Harmful and Beneficial Role of ROS 2017.

Does Metformin Modulate Endoplasmic Reticulum Stress and Autophagy in Type 2 Diabetic Peripheral Blood Mononuclear Cells?

Since type 2 diabetes (T2D) is associated with oxidative stress and metformin has been shown to exert a protective role against the said stress, we wondered whether metformin treatment might also modulate endoplasmic reticulum (ER) stress and autophagy in leukocytes of T2D patients. We studied 53 T2D patients (37 of whom had been treated with metformin 1700 mg for at least 1 year) and 30 healthy volunteers. Leukocytes from both groups of T2D patients exhibited increased protein levels of 78-kDa glucose-regulated protein (GRP78) with respect to controls, whereas activating transcription factor 6 (ATF6) was enhanced specifically in nonmetformin-treated T2D, and (s-xbp1) and phosphorylated euk…

Lipidomics reveals altered biosynthetic pathways of glycerophospholipids and cell signaling as biomarkers of the polycystic ovary syndrome

// Mariona Jove 1, * , Irene Pradas 1, * , Alba Naudi 1, * , Susana Rovira-Llopis 2 , Celia Banuls 2 , Milagros Rocha 2 , Manuel Portero-Otin 1 , Antonio Hernandez-Mijares 2, 3, 4, # , Victor M. Victor 2, 5, # and Reinald Pamplona 1, # 1 Department of Experimental Medicine, Lleida University-Institute for Research in Biomedicine of Lleida (UdL-IRBLleida), 25198 Lleida, Spain 2 Foundation for the Promotion of Healthcare and Biomedical Research in the Valencian Community (FISABIO), Service of Endocrinology, University Hospital Dr. Peset, 46017 Valencia, Spain 3 Fundacion Investigacion Hospital Clinico Universitario/INCLIVA, Valencia University, 46010 Valencia, Spain 4 Department of Medicine, …

Testosterone Levels in Males with Type 2 Diabetes and Their Relationship with Cardiovascular Risk Factors and Cardiovascular Disease

ABSTRACT Introduction One of the factors involved in type 2 diabetes in males is a reduction in levels of testosterone, which has been shown to predict resistance to insulin and the development of cardiovascular diseases. Aim To assess the levels of testosterone in patients with type 2 diabetes and to evaluate their relationship with cardiovascular risk factors, peripheral arterial disease (PAD) and silent myocardial ischemia (SMI). Methods Total testosterone and sex hormone binding globulin were measured and free and bioavailable testosterones were calculated using Vermeulen's formula. Levels of total testosterone ≥12 nmol/L or free testosterone >225 pmol/L were considered normal. PAD was …

Endothelial Nitric Oxide Synthase Regulates T Cell Receptor Signaling at the Immunological Synapse

The role of nitric oxide (NO) in T cells remains controversial, and the origin and localization of endogenous NO and whether it regulates lymphocyte activation are unclear. We show here that, within minutes of binding to antigen, T cells produce NO via endothelial nitric oxide synthase (eNOS). This process required increased intracellular Ca2+ and phosphoinositide3-kinase activity. By using an eNOS-green fluorescent fusion protein and fluorescent probes to detect NO, we show that eNOS translocates with the Golgi apparatus to the immune synapse of T helper cells engaged with antigen-presenting cells (APC), where it was fully activated. Overexpression of eNOS prevented the central coalescence…

Targeting antioxidants to mitochondria: a potential new therapeutic strategy for cardiovascular diseases.

Mitochondria produce large amounts of free radicals and play an important role in the life and death of a cell. Thus, mitochondrial oxidative damage and dysfunction contribute to a number of cell pathologies that manifest themselves through a range of conditions including ischemia-reperfusion injury, sepsis, diabetes, atherosclerosis and, consequently, cardiovascular diseases (CVD). In fact, endothelial dysfunction, characterized by a loss of nitric oxide (NO) bioactivity, occurs early on in the development of atherosclerosis, and determines future vascular complications. Although the molecular mechanisms responsible for mitochondria-mediated disease processes are not yet clear, oxidative s…

A single acute dose of pinitol from a naturally-occurring food ingredient decreases hyperglycaemia and circulating insulin levels in healthy subjects.

A limited amount of research suggests that oral ingestion of pinitol (3-O-methyl-d-chiro-inositol) positively influences glucose tolerance in humans. This study assessed the effects of different doses of pinitol supplementation on glucose tolerance, insulin sensitivity and plasma pinitol concentrations. Thirty healthy subjects underwent two one-day trials in which they consumed a nutritive beverage (Fruit Up®) containing 2.5, 4.0 or 6.0g of pinitol and a corresponding placebo equivalent in both energy and carbohydrates. Blood samples were collected frequently over the 240-min test period. The pinitol-enriched beverage reduced serum glucose and insulin at 45 and 60min, but only at a dose of …

Malnutrition impairs mitochondrial function and leukocyte activation

Abstract Background The aim of this study was to evaluate markers of inflammation, oxidative stress and endothelial function in a disease-related malnutrition (DRM) outpatient population. Methods For this cross-sectional study, a total of 83 subjects were included and clustered in 3 groups: 34 with normonutrition (NN), 21 with DRM without inflammation (DRM-I) and 28 with DRM and inflammation (DRM + I). Nutritional diagnosis was conducted for all subjects according to ASPEN. Biochemical parameters, proinflammatory cytokines, reactive oxygen species production, glutathione, mitochondrial membrane potential, oxygen consumption, adhesion molecules and leukocyte-endothelium interactions were eva…

Effects of metformin on mitochondrial function of leukocytes from polycystic ovary syndrome patients with insulin resistance.

ObjectiveOxidative stress and mitochondrial dysfunction are implicated in polycystic ovary syndrome (PCOS). The present study assesses the effect of metformin treatment on mitochondrial function in polymorphonuclear cells from PCOS subjects. Additionally, we evaluate endocrine parameters and levels of interleukin 6 (IL6) and tumour necrosis factor alpha (TNFα).Design and methodsOur study population was comprised of 35 women of reproductive age diagnosed with PCOS and treated with metformin for 12 weeks, and their corresponding controls (n=41), adjusted by age and BMI. We evaluated the alteration of endocrinological and anthropometrical parameters and androgen levels. Mitochondrial O2 consum…

Discrepancies Between Nitroglycerin and NO-Releasing Drugs on Mitochondrial Oxygen Consumption, Vasoactivity, and the Release of NO

It has been generally acknowledged that the actions of glyceryl trinitrate (GTN) are a result of its bioconversion into NO. However, recent observations have thrown this idea into doubt, with many studies demonstrating that NO is present only when there are high concentrations of GTN. We have explored this discrepancy by developing a new approach that uses confocal microscopy to directly detect NO. Intracellular levels of NO in the rat aortic vascular wall have been compared with those present after incubation with 3 different NO donors (DETA-NO, 3-morpholinosydnonimine, and S -nitroso- N -acetylpenicillamine), endothelial activation with acetylcholine, or administration of GTN. We have al…

Insulin resistance and diabetes in hyperthyroidism: a possible role for oxygen and nitrogen reactive species.

In addition to insulin, glycemic control involves thyroid hormones. However, an excess of thyroid hormone can disturb the blood glucose equilibrium, leading to alterations of carbohydrate metabolism and, eventually, diabetes. Indeed, experimental and clinical hyperthyroidism is often accompanied by abnormal glucose tolerance. A common characteristic of hyperthyroidism and type 2 diabetes is the altered mitochondrial efficiency caused by the enhanced production of reactive oxygen and nitrogen species. It is known that an excess of thyroid hormone leads to increased oxidant production and mitochondrial oxidative damage. It can be hypothesised that these species represent the link between hype…

Moderate weight loss attenuates chronic endoplasmic reticulum stress and mitochondrial dysfunction in human obesity

Abstract Objective In obese patients undergoing caloric restriction, there are several potential mechanisms involved in the improvement of metabolic outcomes. The present study further explores whether caloric restriction can modulate endoplasmic reticulum (ER) stress and mitochondrial function, as both are known to be mechanisms underlying inflammation and insulin resistance (IR) during obesity. Methods A total of 64 obese patients with BMI ≥35 kg/m2 underwent a dietary program consisting of 6 weeks of a very-low-calorie diet followed by 18 weeks of low-calorie diet. We evaluated changes in the metabolic and inflammatory markers -TNFα, hsCRP, complement component 3 (C3c), and retinol bindi…

PGK1-AR axis: Benefits of a novel actor in PCOS pathology.

Perspectives and Potential Applications of Mitochondria-Targeted Antioxidants in Cardiometabolic Diseases and Type 2 Diabetes

There is abundant evidence to suggest that mitochondrial dysfunction is a main cause of insulin resistance and related cardiometabolic comorbidities. On the other hand, insulin resistance is one of the main characteristics of type 2 diabetes, obesity, and metabolic syndrome. Lipid and glucose metabolism require mitochondria to generate energy, and when O2 consumption is low due to inefficient nutrient oxidation, there is an increase in reactive oxygen species, which can impair different types of molecules, including DNA, lipids, proteins, and carbohydrates, thereby inducing proinflammatory processes. Factors which contribute to mitochondrial dysfunction, such as mitochondrial biogenesis and…

Gold Nanoparticles Supported on Nanoparticulate Ceria as a Powerful Agent against Intracellular Oxidative Stress

Ceria-supported gold nanoparticles are prepared exhibiting peroxidase activity and acting as radical traps. Au/CeO2 shows a remarkable biocompatibility as demonstrated by measuring cellular viability, proliferation, and lack of apoptosis for two human cell lines (Hep3B and HeLa). The antioxidant activity of Au/CeO2 against reactive oxygen species (ROS) is demonstrated by studying the cellular behavior of Hep3B and HeLa in a model of cellular oxidative stress. It is determined that Au/CeO2 exhibits higher antioxidant activity than glutathione, the main cytosolic antioxidant compound, and its CeO2 carrier. Overall the result presented here shows the potential of implementing well-established …

Effect of Roux-en-Y Bariatric Bypass Surgery on Subclinical Atherosclerosis and Oxidative Stress Markers in Leukocytes of Obese Patients: A One-Year Follow-Up Study

Little is known about the mechanisms underlying the cardioprotective effect of Roux en-Y gastric bypass (RYGB) surgery. Therefore, the aim of the present study was to investigate whether weight loss associated with RYGB improves the oxidative status of leukocytes and ameliorates subclinical atherosclerotic markers. This is an interventional study of 57 obese subjects who underwent RYGB surgery. We determined biochemical parameters and qualitative analysis of cholesterol, leukocyte and systemic oxidative stress markers &mdash

Relationship between erectile dysfunction and silent myocardial ischemia in type 2 diabetic patients with no known macrovascular complications.

ABSTRACT Introduction Erectile dysfunction (ED) is associated with cardiovascular disease (CVD) because it is highly prevalent among those with cardiovascular risk factors (CVRFs). Moreover, it precedes the development of CVD and is considered a subrogate marker of subclinical CVD. Aim The aim of this study was to evaluate the presence of ED among patients with type 2 diabetes (DM2) without macroangiopathy, and to assess the association between ED and other CVRFs, chronic diabetes complications, silent myocardial ischemia (SMI), and peripheral arterial disease (PAD). Methods One hundred fifty‐four male patients with DM2 and without clinical evidence of CVD were included in the study. The pr…

Chronic consumption of an inositol-enriched carob extract improves postprandial glycaemia and insulin sensitivity in healthy subjects: A randomized controlled trial

Background & aims: Inositols are thought to be mediators of the insulin signalling pathway. We assessed the effects of inositols on glycaemic control in fasting and postprandial states and evaluated lipoprotein profile and LDL particle size in healthy population. Methods: A 12-week double-blind clinical trial was performed with forty healthy subjects administered either an inositol-enriched beverage (IEB) -containing 2.23 g of inositols in 250 ml- or a sucrose-sweetened beverage (SB) twice a day. Anthropometric measurements, fasting glucose levels, insulin and HOMA-IR index, lipoprotein profile and postprandial glucose concentrations (measured using the continuous glucose monitoring system …

Regulation of Oxygen Distribution in Tissues by Endothelial Nitric Oxide

Nitric oxide (NO) decreases cellular oxygen (O 2 ) consumption by competitively inhibiting cytochrome c oxidase. Here, we show that endogenously released endothelial NO, either basal or stimulated, can modulate O 2 consumption both throughout the thickness of conductance vessels and in the microcirculation. Furthermore, we have shown that such modulation regulates O 2 distribution to the surrounding tissues. We have demonstrated these effects by measuring O 2 consumption in blood vessels in a hypoxic chamber and O 2 distribution in the microcirculation using the fluorescent oxygen-probe Ru(phen) 3 2+ . Removal of NO by physical or pharmacological means, or in eNOS −/− mice, abolishes this …

Nano-Jewels in Biology. Gold and Platinum on Diamond Nanoparticles as Antioxidant Systems Against Cellular Oxidative Stress

Diamond nanoparticles (DNPs) obtained by explosive detonation have become commercially available. These commercial DNPs can be treated under Fenton conditions (FeSO(4) and H(2)O(2) at acidic pH) to obtain purer DNP samples with a small average particle size (4 nm) and a large population of surface OH groups (HO-DNPs). These Fenton-treated HO-DNPs have been used as a support of gold and platinum nanoparticles (≤2 nm average size). The resulting materials (Au/HO-DNP and Pt/HO-DNP) exhibit a high antioxidant activity against reactive oxygen species induced in a hepatoma cell line. In addition to presenting good biocompatibility, Au/HO- and Pt/HO-DNP exhibit about a two-fold higher antioxidant …

Serum lipid responses to phytosterol-enriched milk in a moderate hypercholesterolemic population is not affected by apolipoprotein E polymorphism or diameter of low-density lipoprotein particles

Background/Objectives: The importance of both low-density lipoprotein cholesterol (LDLc) size and the apolipoprotein E (Apo E) in the atherogenic process is known, but there is little information with regard to the effect of phytosterols (PS) on these parameters. The aim of this study was to evaluate the influence of PS on lipid profile and LDLc size according to Apo E genotype. Subjects/Methods: This was a randomized parallel trial employing 75 mild-hypercholesterolemic subjects and consisting of two 3-month intervention phases. After 3 months of receiving a standard healthy diet, subjects were divided into two intervention groups: a diet group (n = 34) and a diet+PS group (n = 41) that re…

Influence of obesity on atherogenic dyslipidemia in women with polycystic ovary syndrome.

Background Obesity is known to underlie, at least partially, dyslipidemia in polycystic ovary syndrome (PCOS), but it is unclear whether PCOS status per se increases the risk of alterations of lipoprotein subfractions, which differ in size and atherogenic potential. Our objective was to evaluate whether PCOS influences lipoprotein profile and LDL and HDL subfractions and to study the impact of obesity on these parameters. Materials and methods This was a case–control study conducted in an academic medical centre. The study population consisted of 54 women of fertile age with PCOS and 60 controls adjusted for age and BMI. Biochemical lipid profile and LDL and HDL lipoprotein subfractions (me…

Does Glycemic Control Modulate the Impairment of NLRP3 Inflammasome Activation in Type 2 Diabetes?

Since mitochondrial dysfunction is associated with NOD-like receptor family protein 3 (NLRP3) activation in type 2 diabetes (T2D), which can eventually lead to an impaired immune response, we set out to determine if glycemic control modulates the effects of T2D on the NLRP3 inflammasome. We have studied leukocytes from 61 diabetic patients [25 with glycated hemoglobin (HbA(1c)) 7% and 36 with HbA(1c) 8%] and 40 healthy controls. Total and mitochondrial reactive oxygen species (ROS) production was enhanced in T2D patients, and mitochondrial ROS was more pronounced in those with poor glycemic control. Levels of gene and protein expression of NLRP3 were decreased in both diabetic groups and mo…

Association between irisin and homocysteine in euglycemic and diabetic subjects

Abstract Objectives The aim of study was to explore whether a relationship exists between homocysteine and irisin in type 2 diabetes (T2D) patients—a population with a high risk of developing cardiovascular disease—and euglycemic controls. Design and methods 69 T2D patients and 75 control subjects (adjusted by body mass index (BMI)) were included in the study. Irisin and homocysteine concentrations and anthropometric and biochemical variables were determined. Results Levels of homocysteine were significantly higher (11.0 ± 3.0 vs 12.4 ± 4.2 μmol/l) and levels of irisin were lower (279 ± 58 vs 263 ± 38 ng/ml) in T2D patients. When both T2D and controls were considered, irisin was found to co…

[11C]-DASB microPET imaging in the aged rat: Frontal and meso-thalamic increases in serotonin transporter binding

Whereas molecular imaging studies in the aging human brain have predominantly demonstrated reductions in serotonin transporter (5-HTT) availability, the majority of the rodent studies, using autoradiographic methods, report increases in neural 5-HTT levels with age. To our knowledge, however, no previous rodent studies have assessed this topic in vivo, and therefore it remains unclear whether this discrepancy arises from methodological or inter-species differences. We performed an [(11)C]-DASB microPET study to evaluate the effects of aging on 5-HTT availability in the rat brain. To generate binding potential estimates, quantitative tracer kinetic modeling was applied using the simplified r…

Mitochondria, the NLRP3 Inflammasome, and Sirtuins in Type 2 Diabetes: New Therapeutic TargetsReviewing Editors:Markus Bachschmid, Dylan Burger, Vittorio Calabrese, Amadou Camara, Lukas Kubala, Giuseppe Poli, and Chandan K. Sen

Abstract Significance: Type 2 diabetes mellitus and hyperglycemia can lead to the development of comorbidities such as atherosclerosis and microvascular/macrovascular complications. Both type 2 dia...

Are Mitochondrial Fusion and Fission Impaired in Leukocytes of Type 2 Diabetic Patients?

Mitochondrial fusion/fission alterations have been evaluated in different tissues of type 2 diabetic (T2D) patients. However, it is not known whether mitochondrial dynamics is disturbed in the leukocytes of T2D patients and whether glycemic control affects its regulation. Anthropometric and metabolic parameters in 91 T2D patients (48 with glycated hemoglobin [HbA1c]6.5% and 43 with HbA1c6.5%) were characteristic of the disease when compared with 78 control subjects. We observed increased reactive oxygen species production in leukocytes from diabetic patients, together with a reduced mitochondrial oxygen consumption rate, especially in poorly controlled patients. Mitochondrial fusion was red…

Testosterone administration increases leukocyte-endothelium interactions and inflammation in transgender men

Objective To evaluate the effect of testosterone treatment on metabolic and inflammation parameters and leukocyte-endothelium interactions in transgender men (TGM). Design Prospective observational study. Setting University hospital. Patient(s) One hundred fifty-seven TGM. Intervention(s) Administration of testosterone undecanoate (1,000 mg, intramuscular) every 12 weeks. Main Outcome Measure(s) Endocrine parameters, adhesion molecules (vascular cell adhesion molecule-1, intercellular cell adhesion molecule-1, and E-selectin), proinflammatory cytokines interleukin-6, and tumor necrosis factor alpha were evaluated in serum before and after treatment using Luminex’s xMAP technology. In additi…

Gastrin: an acid-releasing, proliferative and immunomodulatory peptide?

Gastrin release is affected by gastric inflammatory conditions. Antral G cells respond to inflammatory mediators by increasing gastrin secretion. Accumulating experimental evidence suggests that gastrin exerts immunomodulatory and proinflammatory effects. Gastrin could be a contributing factor to these pathologies, which may constitute a new justification for pharmacological blockade of gastrin action.

The role of reactive oxygen species in obesity therapeutics.

Obesity is a major risk factor for multiple severe health conditions, including cardiovascular diseases, diabetes and cancer. It is often related to an increased risk of morbidity and mortality and, as it can be accompanied by non-fatal health problems, quality of life is seriously reduced due to related conditions including hypertension, sleep apnea, osteoarthritis, respiratory problems and infertility. Evidence suggests that oxidative stress is related to obesity and its complications. In obese patients, there is an increase in levels of reactive oxygen species and nitrogen species and antioxidant defenses are undermined in comparison to normal-weight counterparts. In addition, these para…

Effect of weight loss on C3 and C4 components of complement in obese patients

Eur J Clin Invest 2012; 42 (5): 503–509 Abstract Background  Circulating C3 levels are elevated in obese patients, but how this factor is affected after weight loss through diet is a question that is yet unanswered. Therefore, the aim of this study was to evaluate the effects of weight loss on lipid and hydrocarbonated metabolism parameters and on the levels of C3 and C4 components of complement in obese patients. Design  This is a longitudinal intervention study based on a 6-week very low-calorie diet (VLCD), a liquid formula of 603 kcal/day. A total of 131 middle-aged patients were distributed among grades II, III and IV of obesity. Anthropometric parameters, total cholesterol, triglyceri…

The consumption of a bread enriched with dietary fibre and l-carnitine improves glucose homoeostasis and insulin sensitivity in patients with metabolic syndrome

The aim of this study was to evaluate the efficacy of a bakery product enriched with dietary fibre and L-carnitine in countering glucose homoeostasis and insulin sensitivity in patients with and without MetS. This was a 12-week, double-blind, randomized placebo-controlled trial employing fifty-four subjects (28 with MetS and 26 without MetS). After one month (run-in period), subjects were divided into two intervention groups: one received dietary fibre (5.59 g of soluble fibre and 9.49 g of insoluble fibre) plus 2325 mg of L-carnitine enriched bread (n = 26) and the other received placebo bread (n = 28). Anthropometric measurements, biochemical parameters inflammatory markers and LDL subfra…

Efavirenz induces alterations in lipid metabolism through AMPK activation

Summary of results EFV produced an immediate reduction of mitochondrialfunction, evident by the significant and dose-dependentinhibition of mitochondrial O2 consumption and thedecrease of intracellular ATP and Δψm. This metabolicstress promoted the activation of AMPK, triggering severalof its signalling pathways, as EFV induced an increment inCD36 mRNA expression and in intracellular lipid content,which could have been a result of the formation of lipiddroplets. This intracellular lipid increase was not presentin cells treated with Compound C, which points to a keyrole for AMPK in these mechanisms. Conclusion Given that EFV treatment is usually prolonged, thesemechanisms may effect the gene…

In vivo biodistribution of amino-functionalized ceria nanoparticles in rats using positron emission tomography.

A variety of nanoparticles have been proposed for several biomedical applications. To gauge the therapeutic potential of these nanoparticles, in vivo biodistribution is essential and mandatory. In the present study, ceria nanoparticles (5 nm average particle size) were labeled with F-18 to study their in vivo biodistribution in rats by positron emission tomography (PET). The F-18 isotope was anchored by reaction of N-succinimidyl 4-[F-18]fluorobenzoate (F-18-SFB) with a modified nanoparticle surface obtained by silylation with 3-aminopropylsilyl. Radiolabeled ceria nanoparticles accumulated mainly in lungs, spleen, and liver. Metabolic products of the radiolabeled nanoparticulate material w…

Metabolic syndrome enhances endoplasmic reticulum, oxidative stress and leukocyte–endothelium interactions in PCOS

Polycystic ovary syndrome (PCOS) is associated with insulin resistance, which can lead to metabolic syndrome (MetS). Oxidative stress and leukocyte-endothelium interactions are related to PCOS. Our aim was to evaluate whether the presence of MetS in PCOS patients can influence endoplasmic reticulum (ER) and oxidative stress and leukocyte-endothelium interactions.This was a prospective controlled study conducted in an academic medical center. The study population consisted of 148 PCOS women (116 without/32 with MetS) and 112 control subjects (87 without / 25 with MetS). Metabolic parameters, reactive oxygen species (ROS) production, ER stress markers (GRP78, sXBP1, ATF6), leukocyte-endotheli…

Molecular Strategies for Targeting Antioxidants to Mitochondria: Therapeutic Implications

Mitochondrial function and specifically its implication in cellular redox/oxidative balance is fundamental in controlling the life and death of cells, and has been implicated in a wide range of human pathologies. In this context, mitochondrial therapeutics, particularly those involving mitochondria-targeted antioxidants, have attracted increasing interest as potentially effective therapies for several human diseases. For the past 10 years, great progress has been made in the development and functional testing of molecules that specifically target mitochondria, and there has been special focus on compounds with antioxidant properties. In this review, we will discuss several such strategies, …

Comparability of two different polyacrylamide gel electrophoresis methods for the classification of LDL pattern type

Abstract Background The measurement of small dense low-density lipoprotein (sdLDL) particles is relevant when assessing cardiovascular risk. However, there is as yet no referenced method for the determination of LDL subfractions or a standardized comparison of the methods currently available. Therefore, the aim of this study was to compare the pattern of LDL particles measured by polyacrylamide tube gel electrophoresis (PTGE) and polyacrylamide gradient gel electrophoresis (PGGE) and to correlate the results with triglyceride concentration. Materials and methods Serum samples were collected from 177 patients. Lipid profile and LDL particle size were assessed using PTGE and PGGE. Results Pea…

Characterization of Differentially Expressed Circulating miRNAs in Metabolically Healthy versus Unhealthy Obesity

Obese individuals without metabolic comorbidities are categorized as metabolically healthy obese (MHO). MicroRNAs (miRNAs) may be implicated in MHO. This cross-sectional study explores the link between circulating miRNAs and the main components of metabolic syndrome (MetS) in the context of obesity. We also examine oxidative stress biomarkers in MHO vs. metabolically unhealthy obesity (MUO). We analysed 3536 serum miRNAs in 20 middle-aged obese individuals: 10 MHO and 10 MUO. A total of 159 miRNAs were differentially expressed, of which, 72 miRNAs (45.2%) were higher and 87 miRNAs (54.7%) were lower in the MUO group. In addition, miRNAs related to insulin signalling and lipid metabolism pat…

Mitochondrial complex I impairment in leukocytes from type 2 diabetic patients.

Diabetes is associated with oxidative stress. This study evaluated the rates of oxidative stress and mitochondrial impairment in type 2 diabetes patients. The study population consisted of 182 diabetic patients and 50 body-composition- and age-matched controls. We assessed anthropometric and metabolic parameters and mitochondrial function by evaluating mitochondrial oxygen (O2) consumption, reactive oxygen species (ROS) production, glutathione (GSH) levels, GSH/GSSG ratio, mitochondrial membrane potential, and mitochondrial complex I activity in polymorphonuclear cells from diabetes type 2 patients. We found an increase in waist circumference and augmented serum levels of triglycerides, pro…

Mitochondrial Alterations and Enhanced Human Leukocyte/Endothelial Cell Interactions in Type 1 Diabetes

Type 1 diabetes has been associated with oxidative stress. This study evaluates the rates of oxidative stress, mitochondrial function, leukocyte&ndash

Induction of oxidative stress and human leukocyte/endothelial cell interactions in polycystic ovary syndrome patients with insulin resistance.

Insulin resistance is a feature of polycystic ovary syndrome (PCOS) and is related to mitochondrial and endothelial function.We tested whether hyperandrogenic insulin-resistant women with PCOS, who have an increased risk of vascular disease, display impaired leukocyte-endothelium interactions, and mitochondrial dysfunction.This was a prospective controlled study conducted in an academic medical center.The study population consisted of 43 lean reproductive-age women with PCOS and 39 controls subjects.We evaluated anthropometric and metabolic parameters, adhesion molecules, and interactions between leukocytes and human umbilical vein endothelial cells. Mitochondrial function was studied by as…

Involvement of leucocyte/endothelial cell interactions in anorexia nervosa.

Background Anorexia nervosa is a common psychiatric disorder in adolescence and is related to cardiovascular complications. Our aim was to study the effect of anorexia nervosa on metabolic parameters, leucocyte–endothelium interactions, adhesion molecules and proinflammatory cytokines. Materials and Methods This multicentre, cross-sectional, case–control study employed a population of 24 anorexic female patients and 36 controls. We evaluated anthropometric and metabolic parameters, interactions between leucocytes polymorphonuclear neutrophils (PMN) and human umbilical vein endothelial cells (HUVEC), proinflammatory cytokines such as tumour necrosis factor alpha (TNF-α) and interleukin-6 (IL…

Therapeutic implications of targeting antioxidants to mitochondria

Abstract Redox and oxidative balance are mainly regulated by mitochondria, which control the life and death of cells and organisms, and are therefore implicated in multiple pathologies. Mitochondria can be considered key organelles to be used in different therapeutically approaches, and mitochondria-targeted antioxidants have already shown great potential in the treatment of various human diseases. In fact, major progress has been achieved in the development of different molecules targeted to mitochondria. In this chapter, we will discuss the various strategies that have been employed, such as molecules conjugated with lipophilic cations (e.g., triphenylphosphonium) and peptide-based compou…

Metformin modulates human leukocyte/endothelial cell interactions and proinflammatory cytokines in polycystic ovary syndrome patients

Abstract Objective We aim to assess the effect of metformin treatment on metabolic parameters, endothelial function and inflammatory markers in polycystic ovary syndrome (PCOS) subjects. Methods The study population consisted of 40 reproductive-age women with PCOS, who underwent treatment with metformin during a 12-week period, and their corresponding matched controls (n = 44). We evaluated endocrinological parameters, adhesion molecules (vascular cell adhesion molecule 1 (VCAM-1), intercellular cell adhesion molecule 1 (ICAM-1) and E-selectin) and proinflammatory cytokines (interleukin 6 (IL-6) and tumor necrosis factor alpha (TNFα)) in serum. In addition, interactions between human umbili…

THE EFFECTS OF AGING ON DOPAMINERGIC NEUROTRANSMISSION A microPET STUDY OF [11C]-raclopride BINDING IN THE AGED RODENT BRAIN

Rodent models are frequently used in aging re search to investigate biochemical age effects and aid in the development of therapies for pathological and non pathological age related degenerative processes In order to validate the use of animal models in aging research and pave the way for longitudinal intervention based animal studies, the consistency of cerebral aging processes across species needs to be evaluated The dopaminergic system seems particularly susceptible to the aging process, and one of the most consistent findings in human brain aging research is a decline in striatal D2-like receptor (D2R) availability, quantifiable by positron emission tomography (PET) imaging In this stud…

Mitochondrial dynamics in type 2 diabetes: Pathophysiological implications

Mitochondria play a key role in maintaining cellular metabolic homeostasis. These organelles have a high plasticity and are involved in dynamic processes such as mitochondrial fusion and fission, mitophagy and mitochondrial biogenesis. Type 2 diabetes is characterised by mitochondrial dysfunction, high production of reactive oxygen species (ROS) and low levels of ATP. Mitochondrial fusion is modulated by different proteins, including mitofusin-1 (MFN1), mitofusin-2 (MFN2) and optic atrophy (OPA-1), while fission is controlled by mitochondrial fission 1 (FIS1), dynamin-related protein 1 (DRP1) and mitochondrial fission factor (MFF). PARKIN and (PTEN)-induced putative kinase 1 (PINK1) partici…

Insulin Resistance in PCOS Patients Enhances Oxidative Stress and Leukocyte Adhesion: Role of Myeloperoxidase

Cardiovascular diseases and oxidative stress are related to polycystic ovary syndrome (PCOS) and insulin resistance (IR). We have evaluated the relationship between myeloperoxidase (MPO) and leukocyte activation in PCOS patients according to homeostatic model assessment of IR (HOMA-IR), and have explored a possible correlation between these factors and endocrine and inflammatory parameters. This was a prospective controlled study conducted in an academic medical center. The study population consisted of 101 PCOS subjects and 105 control subjects. We divided PCOS subjects into PCOS non-IR (HOMA-IR2.5). Metabolic and anthropometric parameters, total and mitochondrial reactive oxygen species (…

Does Empagliflozin Modulate Leukocyte–Endothelium Interactions, Oxidative Stress, and Inflammation in Type 2 Diabetes?

Sodium-glucose co-transporter 2 inhibitors (iSGLT2) have been linked to cardiovascular risk reduction in patients with type 2 diabetes (T2D). However, their underlying molecular mechanisms remain unclear. This study aimed to evaluate the effects of empagliflozin, a novel potent and selective iSGLT-2, on anthropometric and endocrine parameters, leukocyte–endothelium interactions, adhesion molecules, ROS production, and NFkB-p65 transcription factor expression. According to standard clinical protocols, sixteen T2D patients receiving 10 mg/day of empagliflozin were followed-up for 24 weeks. Anthropometric and analytical measurements were performed at baseline, 12 weeks, and 24 weeks. Interacti…

Chronic periodontitis impairs polymorphonuclear leucocyte-endothelium cell interactions and oxidative stress in humans.

Aim To evaluate the relationship between oxidative stress parameters in polymorphonuclear leucocytes (PMNs) and PMN-endothelial cell interactions in patients with chronic periodontitis (CP) according to different degrees of severity of the disease. Materials and methods For this cross-sectional study, 182 subjects were divided into four groups according to degree of CP: without CP (n = 37), mild CP (n = 59), moderate CP (n = 51), and severe CP (n = 35). We determined anthropometric and biochemical variables, periodontal parameters, inflammatory markers, oxidative stress parameters (superoxide and mitochondrial membrane potential), and PMN-endothelium cell interactions (rolling flux, velocit…

Role of endothelial nitric oxide in pulmonary and systemic arteries during hypoxia

Abstract Our aim was to investigate the role played by endothelial nitric oxide (NO) during acute vascular response to hypoxia, as a modulator of both vascular tone (through guanylate cyclase (sGC) activation) and mitochondrial O2 consumption (through competitive inhibition of cytochrome-c-oxydase (CcO)). Organ bath experiments were performed and O2 consumption (Clark electrode) was determined in isolated aorta, mesenteric and pulmonary arteries of rats and eNOS-knockout mice. All pre-contracted vessels exhibited a triphasic hypoxic response consisting of an initial transient contraction (not observed in vessels from eNOS-knockout mice) followed by relaxation and subsequent sustained contra…

Microbiota-Mitochondria Inter-Talk: A Potential Therapeutic Strategy in Obesity and Type 2 Diabetes

The rising prevalence of obesity and type 2 diabetes (T2D) is a growing concern worldwide. New discoveries in the field of metagenomics and clinical research have revealed that the gut microbiota plays a key role in these metabolic disorders. The mechanisms regulating microbiota composition are multifactorial and include resistance to stress, presence of pathogens, diet, cultural habits and general health conditions. Recent evidence has shed light on the influence of microbiota quality and diversity on mitochondrial functions. Of note, the gut microbiota has been shown to regulate crucial transcription factors, coactivators, as well as enzymes implicated in mitochondrial biogenesis and meta…

Integrated molecular signaling involving mitochondrial dysfunction and alteration of cell metabolism induced by tyrosine kinase inhibitors in cancer.

Cancer cells have unlimited replicative potential, insensitivity to growth-inhibitory signals, evasion of apoptosis, cellular stress, and sustained angiogenesis, invasiveness and metastatic potential. Cancer cells adequately adapt cell metabolism and integrate several intracellular and redox signaling to promote cell survival in an inflammatory and hypoxic microenvironment in order to maintain/expand tumor phenotype. The administration of tyrosine kinase inhibitor (TKI) constitutes the recommended therapeutic strategy in different malignancies at advanced stages. There are important interrelationships between cell stress, redox status, mitochondrial function, metabolism and cellular signali…

MicroRNAs and Oxidative Stress: An Intriguing Crosstalk to Be Exploited in the Management of Type 2 Diabetes

Type 2 diabetes is a chronic disease widespread throughout the world, with significant human, social, and economic costs. Its multifactorial etiology leads to persistent hyperglycemia, impaired carbohydrate and fat metabolism, chronic inflammation, and defects in insulin secretion or insulin action, or both. Emerging evidence reveals that oxidative stress has a critical role in the development of type 2 diabetes. Overproduction of reactive oxygen species can promote an imbalance between the production and neutralization of antioxidant defence systems, thus favoring lipid accumulation, cellular stress, and the activation of cytosolic signaling pathways, and inducing β-cell dysfunction, insul…

Association of Serum Retinol Binding Protein 4 with Atherogenic Dyslipidemia in Morbid Obese Patients

Retinol binding protein 4 (RBP4) is an adipokine that may contribute to the development of insulin resistance. However, how this adipokine is affected and its possible involvement in lipid metabolism in obese patients with varying degrees of insulin resistance is yet to be determined. A total of 299 middle-aged morbid obese patients (BMI>40 kg/m(2)) were divided in euglycemic, metabolic syndrome or type 2 diabetic. Anthropometric measurements, biochemical variables and systemic RBP4 levels were determined. RBP4 levels were significantly higher in patients with metabolic syndrome and type 2 diabetes than in euglycemic subjects (42.9±14.6; 42.3±17.0 and 37.4±11.7 µg/ml, respectively) and corr…

Association between Proinflammatory Markers, Leukocyte–Endothelium Interactions, and Carotid Intima–Media Thickness in Type 2 Diabetes: Role of Glycemic Control

Glycated hemoglobin monitorization could be a tool for maintaining type 2 diabetes (T2D) under control and delaying the appearance of cardiovascular events. This cross-sectional study was designed to assess the role of glycemic control in modulating early-stage markers of cardiovascular complications. One hundred and eight healthy controls and 161 type 2 diabetic patients were recruited and distributed according to their glycemic control, setting the threshold at 6.5% (good control). Biochemical and anthropometrical parameters were registered during the initial visit, and peripheral blood was extracted to obtain polymorphonuclear cells and analyze inflammatory markers, adhesion molecules, l…

Relationship Between Oxidative Stress, ER Stress, and Inflammation in Type 2 Diabetes: The Battle Continues

Type 2 diabetes (T2D) is a metabolic disorder characterized by hyperglycemia and insulin resistance in which oxidative stress is thought to be a primary cause. Considering that mitochondria are the main source of ROS, we have set out to provide a general overview on how oxidative stress is generated and related to T2D. Enhanced generation of reactive oxygen species (ROS) and oxidative stress occurs in mitochondria as a consequence of an overload of glucose and oxidative phosphorylation. Endoplasmic reticulum (ER) stress plays an important role in oxidative stress, as it is also a source of ROS. The tight interconnection between both organelles through mitochondrial-associated membranes (MAM…

Erythrocytes labeled with [18F]SFB as an alternative to radioactive CO for quantification of blood volume with PET

Inhaled radioactive CO is currently the tracer of choice for blood volume quantification by positron emission tomography (PET). This measurement is of great interest for several clinical and research applications. However, owing to the short half-life of the radiolabeled CO, it can only be used in centers equipped with a cyclotron. In the present work, we propose an alternative method to label the red blood cells with [(18) F] in order to obtain blood volume measurements by PET. The use of the radioactive synthon [(18) F] N-succinimidyl 4-[(18) F]fluorobenzoate ([(18) F]SFB) was evaluated for erythrocyte labeling and PET blood volume imaging. The images provided by [(18) F]SFB labeled eryth…

The purine analogues abacavir and didanosine increase acetaminophen-induced hepatotoxicity by enhancing mitochondrial dysfunction

Background NRTIs are essential components of HIV therapy with well-documented, long-term mitochondrial toxicity in hepatic cells, but whose acute effects on mitochondria are unclear. As acetaminophen-induced hepatotoxicity also involves mitochondrial interference, we hypothesized that it would be exacerbated in the context of ART. Methods We evaluated the acute effects of clinically relevant concentrations of the most widely used NRTIs, alone or combined with acetaminophen, on mitochondrial function and cellular viability. Results The purine analogues abacavir and didanosine produced an immediate and concentration-dependent inhibition of oxygen consumption and complex I and III activity. Th…

Pinitol alleviates systemic inflammatory cytokines in human obesity by a mechanism involving unfolded protein response and sirtuin 1

Summary Background & aims It is known that pinitol acts as a mediator of the insulin-signaling pathway, though little is known about its anti-inflammatory effect in human obesity. Therefore, this study aimed to evaluate the effect of pinitol on peripheral blood mononuclear cells (PBMCs) and visceral (VAT) and subcutaneous adipose tissues (SAT), focusing on the involvement of endoplasmic reticulum (ER) stress and sirtuin 1 (SIRT1). Methods In the intervention study, thirteen obese subjects consumed a pinitol-enriched beverage (PEB) for 12 weeks. In the ex vivo study, a biopsy of VAT and SAT was removed from thirty-four obese patients and incubated with D-pinitol for 48 h. Results The consump…

The mitochondria-targeted antioxidant MitoQ modulates oxidative stress, inflammation and leukocyte-endothelium interactions in leukocytes isolated from type 2 diabetic patients

It is not known if the mitochondria-targeted antioxidants such as mitoquinone (MitoQ) can modulate oxidative stress and leukocyte-endothelium interactions in T2D patients. We aimed to evaluate the beneficial effect of MitoQ on oxidative stress parameters and leukocyte-endothelium interactions in leukocytes of T2D patients. The study population consisted of 98 T2D patients and 71 control subjects. We assessed metabolic and anthropometric parameters, mitochondrial reactive oxygen species (ROS) production, glutathione peroxidase 1 (GPX-1), NFκB-p65, TNFα and leukocyte-endothelium interactions. Diabetic patients exhibited higher weight, BMI, waist circumference, SBP, DBP, glucose, insulin, HOMA…

Phytosterols: Nutritional Health Players in the Management of Obesity and Its Related Disorders

Obesity and its related disorders, such as diabetes and cardiovascular risk, represent an emerging global health issue. Even though genetic factors seem to be the primary actors in the development and progression of these diseases, dietary choices also appear to be of crucial importance. A healthy diet combined with physical activity have been shown to ameliorate glycaemic levels and insulin sensitivity, reduce body weight and the risk of chronic diseases, and contribute to an overall improvement in quality of life. Among nutrients, phytosterols have become the focus of growing attention as novel functional foods in the management of metabolic disorders. Phytosterols are natural plant compo…

Effects of simvastatin, ezetimibe and simvastatin/ezetimibe on mitochondrial function and leukocyte/endothelial cell interactions in patients with hypercholesterolemia

Cholesterol-lowering therapy has been related with several beneficial effects; however, its influence on oxidative stress and endothelial function is not fully elucidated.To investigate the effect of simvastatin and ezetimibe on mitochondrial function and leukocyte-endothelium interactions in polymorphonuclear cells of hyperlipidemic patients.Thirty-nine hyperlipidemic patients were randomly assigned to one of two groups: one received simvastatin (40 mg/day) and the other received ezetimibe (10 mg/day) for 4 weeks, after which both groups were administered combined therapy for an additional 4-week period. Lipid profile, mitochondrial parameters (oxygen consumption, reactive oxygen species (…

Understanding the implication of autophagy in the activation of hepatic stellate cells in liver fibrosis: are we there yet?

Liver fibrosis (LF) occurs as a result of persistent liver injury and can be defined as a pathologic, chronic, wound-healing process in which functional parenchyma is progressively replaced by fibrotic tissue. As a phenomenon involved in the majority of chronic liver diseases, and therefore prevalent, it exerts a significant impact on public health. This impact becomes even more patent given the lack of a specific pharmacological therapy, with LF only being ameliorated or prevented through the use of agents that alleviate the underlying causes. Hepatic stellate cells (HSCs) are fundamental mediators of LF, which, activated in response to pro-fibrotic stimuli, transdifferentiate from a quies…

Effects of phytosterol ester-enriched low-fat milk on serum lipoprotein profile in mildly hypercholesterolaemic patients are not related to dietary cholesterol or saturated fat intake

Phytosterols (PS) are recommended to reduce LDL-cholesterol. However, the influence of cholesterol and fat intake on the lipid-lowering effect of PS in mildly hypercholesterolaemia is unclear. Thus, the aim of the present study was to evaluate whether the efficacy of PS is related to the composition of saturated fat and dietary cholesterol intake. Additionally, serum carotenoid content was analysed to evaluate to what extent it was undermined by PS. This was a 3-month randomised, parallel trial with a three-arm design. Patients were divided into three groups: healthy diet (n 24), healthy diet + PS (n 31) and free diet + PS (n 29), receiving 2 g/d of PS. Healthy and free diets were character…

Human leukocyte/endothelial cell interactions and mitochondrial dysfunction in type 2 diabetic patients and their association with silent myocardial ischemia.

OBJECTIVE Diabetes is associated with oxidative stress and increased mortality, but a possible correlation between leukocyte-endothelium interactions, oxidative stress, and silent myocardial ischemia (SMI) is yet to be confirmed. RESEARCH DESIGN AND METHODS Mitochondrial dysfunction and interactions between leukocytes and human umbilical vein endothelial cells were evaluated in 200 type 2 diabetic patients (25 with SMI) and 60 body composition– and age-matched control subjects. A possible correlation between these parameters and the onset of SMI was explored, and anthropometric and metabolic parameters were also analyzed. RESULTS Waist, levels of triglycerides, proinflammatory cytokines (i…

eNOS S-nitrosylates β-actin on Cys374 and regulates PKC-θ at the immune synapse by impairing actin binding to profilin-1.

The actin cytoskeleton coordinates the organization of signaling microclusters at the immune synapse (IS); however, the mechanisms involved remain poorly understood. We show here that nitric oxide (NO) generated by endothelial nitric oxide synthase (eNOS) controls the coalescence of protein kinase C-¿ (PKC-¿) at the central supramolecular activation cluster (c-SMAC) of the IS. eNOS translocated with the Golgi to the IS and partially colocalized with F-actin around the c-SMAC. This resulted in reduced actin polymerization and centripetal retrograde flow of ß-actin and PKC-¿ from the lamellipodium-like distal (d)-SMAC, promoting PKC-¿ activation. Furthermore, eNOS-derived NO S-nitrosylated ß-…

Systemic Oxidative Stress and Visceral Adipose Tissue Mediators of NLRP3 Inflammasome and Autophagy Are Reduced in Obese Type 2 Diabetic Patients Treated with Metformin.

Obesity is a low-grade inflammatory condition affecting a range of individuals, from metabolically healthy obese (MHO) subjects to type 2 diabetes (T2D) patients. Metformin has been shown to display anti-inflammatory properties, though the underlying molecular mechanisms are unclear. To study whether the effects of metformin are mediated by changes in the inflammasome complex and autophagy in visceral adipose tissue (VAT) of obese patients, a biopsy of VAT was obtained from a total of 68 obese patients undergoing gastric bypass surgery. The patients were clustered into two groups: MHO patients and T2D patients treated with metformin. Patients treated with metformin showed decreased levels o…

Oxidative and endoplasmic reticulum stress is impaired in leukocytes from metabolically unhealthy vs healthy obese individuals.

BACKGROUND: Oxidative stress and inflammation are related to obesity, but the influence of metabolic disturbances on these parameters and their relationship with endoplasmic reticulum (ER) stress is unknown. Therefore, this study was performed to evaluate whether metabolic profile influences ER and oxidative stress in an obese population with/without comorbidities. SUBJECTS AND METHODS: A total of 113 obese patients were enrolled in the study; 29 were metabolically healthy (MHO), 53 were metabolically abnormal (MAO) and 31 had type 2 diabetes (MADO). We assessed metabolic parameters, proinflammatory cytokines (TNF alpha and IL-6), mitochondrial and total reactive oxygen species (ROS) produc…

The Mitochondria-Targeted Antioxidant MitoQ Modulates Mitochondrial Function and Endoplasmic Reticulum Stress in Pancreatic β Cells Exposed to Hyperglycaemia.

Background/aims Mitochondria-targeted antioxidants such as mitoquinone (MitoQ) have demonstrated protective effects against oxidative damage in several diseases. The increase in reactive oxygen species (ROS) production during glucose metabolism in β cells can be exacerbated under hyperglycaemic conditions such as type 2 diabetes (T2D), thus contributing to β cell function impairment. In the present work, we aimed to evaluate the effect of MitoQ on insulin secretion, oxidative stress, endoplasmic reticulum (ER) stress and nuclear factor kappa B (NFκB) signalling in a pancreatic β cell line under normoglycaemic (NG, 11.1 mM glucose), hyperglycaemic (HG, 25 mM glucose) and lipidic (palmitic ac…

Mitophagy in human astrocytes treated with the antiretroviral drug Efavirenz: Lack of evidence or evidence of the lack

Efavirenz (EFV), a first generation non-nucleoside analogue reverse transcriptase inhibitor widely employed in combination antiretroviral therapy regimens over the last 20 years, has been associated with a wide range of neuropsychiatric effects and has also been linked with HIV-associated neurocognitive disorder (HAND). EFV has been reported to alter mitochondrial dysfunction and bioenergetics in different cell types, including astrocytes. Here, we analyzed whether this mitochondrial effect is associated with alterations in autophagy and, more specifically, mitophagy. U251-MG cells were exposed to EFV (10 and 25 μM; 24 h) and the effect was compared with that of CCCP - an uncoupler of the m…

Mitochondrial (dys)function - a factor underlying the variability of efavirenz-induced hepatotoxicity?

Background and Purpose The non-nucleoside analogue reverse transcriptase inhibitor efavirenz is associated with hepatic toxicity and metabolic disturbances. Although the mechanisms involved are not clear, recent evidence has pinpointed a specific mitochondrial action of efavirenz accompanied by the induction of an endoplasmic reticulum (ER) stress/unfolded protein response in human hepatic cells. The aim of this study was to further investigate the involvement of this organelle by evaluating efavirenz's effects in cells lacking functional mitochondria (rho°) and comparing them with those of the typical mitotoxic agent rotenone, a standard complex I inhibitor, and the ER stress inducer thaps…

Mitochondria and T2D: Role of Autophagy, ER Stress, and Inflammasome.

Type 2 diabetes (T2D) is one of the main current threats to human health. Both T2D and its numerous clinical complications are related to mitochondrial dysfunction and oxidative stress. Over the past decade, great progress has been made in extending our knowledge about the signaling events regulated by mitochondria. However, the links among mitochondrial impairment, oxidative stress, autophagy, endoplasmic reticulum (ER) stress, and activation of the inflammasome still need to be clarified. In light of this deficit, we aim to provide a review of the existing literature concerning the complicated crosstalk between mitochondrial impairment, autophagy, ER stress, and the inflammasome in the mo…

Altered Mitochondrial Function and Oxidative Stress in Leukocytes of Anorexia Nervosa Patients

ContextAnorexia nervosa is a common illness among adolescents and is characterised by oxidative stress.ObjectiveThe effects of anorexia on mitochondrial function and redox state in leukocytes from anorexic subjects were evaluated.Design and settingA multi-centre, cross-sectional case-control study was performed.PatientsOur study population consisted of 20 anorexic patients and 20 age-matched controls, all of which were Caucasian women.Main outcome measuresAnthropometric and metabolic parameters were evaluated in the study population. To assess whether anorexia nervosa affects mitochondrial function and redox state in leukocytes of anorexic patients, we measured mitochondrial oxygen consumpt…

Effect of consumption of a carob pod inositol-enriched beverage on insulin sensitivity and inflammation in middle-aged prediabetic subjects.

This study assessed the effects of an inositol-enriched beverage (IEB) on blood glucose levels and inflammation status in subjects with an impaired fasting glucose (IFG) state according to body mass index (BMI). This was a 12 week, double-blind, randomized, controlled trial employing forty-four IFG subjects (fasting glucose levels 100-125 mg dl-1) that were divided into two intervention groups: one receiving a IEB (n = 24) containing mainly pinitol (2.0 g twice a day), and the other a sweetened beverage based on sucrose (SB; n = 20). Anthropometric and biochemical measurements, postprandial and fasting nocturnal glycaemia (continuous glucose monitoring system), and inflammatory parameters (…

Mitochondrial Oxidative Stress in Diabetes

Abstract Diabetes is a multifactorial disease associated with serious comorbidities. This condition has been related to oxidative stress and, as a consequence, to overproduction of reactive oxygen species (ROS), which are known to be produced by different sources in diabetes. Excessive production of ROS can be harmful, making antioxidant defenses of vital importance. Dietary antioxidants, such as vitamin E or vitamin C, polyphenols and flavonoids have been used to modulate the oxidative stress created in diabetes, producing contradictory results in clinical trials, perhaps as a consequence of the targets selected and/or the design of the studies in question. This chapter considers the proce…

Complex I dysfunction and tolerance to nitroglycerin: an approach based on mitochondrial-targeted antioxidants.

Nitroglycerin (GTN) tolerance was induced in vivo (rats) and in vitro (rat and human vessels). Electrochemical detection revealed that the incubation dose of GTN (5×10 −6 mol/L) did not release NO or modify O 2 consumption when administered acutely. However, development of tolerance produced a decrease in both mitochondrial O 2 consumption and the K m for O 2 in animal and human vessels and endothelial cells in a noncompetitive action. GTN tolerance has been associated with impairment of GTN biotransformation through inhibition of aldehyde dehydrogenase (ALDH)-2, and with uncoupling of mitochondrial respiration. Feeding rats with mitochondrial-targeted antioxidants (mitoquinone [MQ]) and i…

Does Metformin Protect Diabetic Patients from Oxidative Stress and Leukocyte-Endothelium Interactions?

Since metformin can exert beneficial vascular effects, we aimed at studying its effect on reactive oxygen species (ROS) production, antioxidant enzyme expression, levels of adhesion molecules, and leukocyte-endothelium interactions in the leukocytes from type 2 diabetic (T2D) patients. The study was carried out in 72 T2D patients (41 of whom were treated with metformin for at least 12 months at a dose of 1700 mg per day), and in 40 sex- and age-matched control subjects. Leukocytes from T2D patients exhibited enhanced levels of mitochondrial ROS and decreased mRNA levels of glutathione peroxidase 1 (gpx1) and sirtuin 3 (sirt3) with respect to controls, whereas metformin was shown to revert t…

The Mitochondrial Antioxidant SS-31 Modulates Oxidative Stress, Endoplasmic Reticulum Stress, and Autophagy in Type 2 Diabetes

Mitochondrial dysfunction has been shown to play a central role in the pathophysiology of type 2 diabetes (T2D), and mitochondria-targeted agents such as SS-31 are emerging as a promising strategy for its treatment. We aimed to study the effects of SS-31 on leukocytes from T2D patients by evaluating oxidative stress, endoplasmic reticulum (ER) stress and autophagy. Sixty-one T2D patients and 53 controls were included. Anthropometric and analytical measurements were performed. We also assessed reactive oxygen species (ROS) production, calcium content, the expression of ER stress markers GRP78, CHOP, P-eIF2&alpha

Is Myeloperoxidase a Key Component in the ROS-Induced Vascular Damage Related to Nephropathy in Type 2 Diabetes?

AbstractIt is still unclear whether microvascular complications of type 2 diabetes correlate with leukocyte-endothelium interactions and/or myeloperoxidase (MPO) levels. In the present study, we found that serum levels of glucose, the rate of ROS and MPO concentration were higher in type 2 diabetic patients. Patients with nephropathy (39.6%) presented higher MPO levels that correlate positively with the albumin/creatinine ratio (r=0.59, p<0.05). In addition, nephropatic patients showed increased leukocyte-endothelium interactions due to an undermining of polymorphonuclear leukocytes (PMN) rolling velocity and increased rolling flux and adhesion, which was accompanied by a rise in levels of …

Mitochondrial complex I impairment in leukocytes from polycystic ovary syndrome patients with insulin resistance.

Insulin resistance is a feature of polycystic ovary syndrome (PCOS) and is related to mitochondrial function.Our objective was to assess mitochondrial function by evaluating mitochondrial oxygen (O(2)) consumption, reactive oxygen species (ROS) production, levels of glutathione (GSH), the oxidized glutathione/GSH ratio, TNFalpha levels, and membrane potential. Additionally, we have evaluated mitochondrial complex I as a target of the oxidative stress responsible for PCOS in polymorphonuclear cells.This was a prospective controlled study conducted in an academic medical center.The study population consisted of 20 lean reproductive-age women with PCOS and 20 body composition-matched controls.…

Obesity impairs leukocyte‐endothelium cell interactions and oxidative stress in humans

Background:To evaluate the relationship between leukocyte‐endothelial cellinteractions and oxidative stress parameters in non‐diabetic patients with differentgrades of obesity.Material and methods:For this cross‐sectional study, 225 subjects wererecruited from January 1, 2014 to December 31, 2016 and divided into groupsaccording to BMI (40 kg/m²). We determined clin-ical parameters, systemic inflammatory markers, soluble cellular adhesion mole-cules, leukocyte‐endothelium cell interactions—rolling flux, velocity and adhesion—, oxidative stress parameters—total ROS, total superoxide, glutathione—andmitochondrial membrane potential in leukocytes.Results:We verified that HOMA‐IR and hsCRP incr…

Chronic consumption of an inositol-enriched beverage ameliorates endothelial dysfunction and oxidative stress in type 2 diabetes

The anti-diabetic properties of an inositol-enriched beverage (IEB) on the endothelial function and redox status in diabetic subjects were assessed. This was a 12-week, double-blind randomized controlled trial employing thirty-eight diabetic subjects that were divided into two intervention groups: one receiving an IEB and the other a sucrose-enriched beverage. Subjects consuming IEB exhibited a significant decrease in triacylglycerol (8.82%) and HbA1c (4.53%) levels. Continuous glucose monitoring revealed a significant net reduction of 2.51 and 7.11% during postprandial and overnight fasting periods after consumption of IEB, respectively. Moreover, IEB improved endothelial function by reduc…

Metformin induces lipid changes on sphingolipid species and oxidized lipids in polycystic ovary syndrome women.

Metformin is one of the treatments used for pcoS pathology decreasing body weight, plasma androgen, FSH and glucose levels. Unfortunately, there is little known about metformin’s effects on lipid metabolism, a crucial process in pcoS pathology. We have employed a lipidomic approach to explore alterations in the plasma lipid profile of patients with PCOS following metformin treatment. The aim is to offer new insights about the effect of metformin in PCOS patients. Plasma samples were obtained from 27 subjects prior to and following 12 weeks of metformin treatment. A detailed biochemical characterization and lipidomic profile was performed. Metformin reduces BMI, HOMA-IR, fSH and androstenedi…

Evaluation of cardiovascular risk and oxidative stress parameters in hypercholesterolemic subjects on a standard healthy diet including low-fat milk enriched with plant sterols

A healthy diet and plant sterols (PS) are recommended for reducing low-density lipoprotein (LDL) cholesterol and, subsequently, the risk of premature cardiovascular disease PS mediate a decrease in fat-soluble vitamin concentration, which can lead to a general impairment of antioxidative defenses and an increase in oxidative stress. Thus, we evaluated the effects of a healthy diet, including PS-enriched low-fat milk, on cardiovascular risk and oxidative stress parameters in hypercholesterolemic subjects. This was a randomized parallel trial employing 40 subjects and consisting of two 3-month intervention phases. After 3 months on a standard healthy diet, subjects were divided into two inter…

Mechanisms of action of metformin in type 2 diabetes: Effects on mitochondria and leukocyte-endothelium interactions.

Type 2 diabetes (T2D) is a very prevalent, multisystemic, chronic metabolic disorder closely related to atherosclerosis and cardiovascular diseases. It is characterised by mitochondrial dysfunction and the presence of oxidative stress. Metformin is one of the safest and most effective anti-hyperglycaemic agents currently employed as first-line oral therapy for T2D. It has demonstrated additional beneficial effects, unrelated to its hypoglycaemic action, on weight loss and several diseases, such as cancer, cardiovascular disorders and metabolic diseases, including thyroid diseases. Despite the vast clinical experience gained over several decades of use, the mechanism of action of metformin i…

Transdiagnostic neurocognitive deficits in patients with type 2 diabetes mellitus, major depressive disorder, bipolar disorder, and schizophrenia: A 1-year follow-up study

AbstractBackgroundImpairments in neurocognition are critical factors in patients with major depressive disorder (MDD), bipolar disorder (BD), and schizophrenia (SZ), and also in those with somatic diseases such as type 2 diabetes mellitus (T2DM). Intriguingly, these severe mental illnesses are associated with an increased co-occurrence of diabetes (direct comorbidity). This study sought to investigate the neurocognition and social functioning across T2DM, MDD, BD, and SZ using a transdiagnostic and longitudinal approach.MethodsA total of 165 subjects, including 30 with SZ, 42 with BD, 35 with MDD, 30 with T2DM, and 28 healthy controls (HC), were assessed twice at a 1-year interval using a c…

In vivo molecular imaging of the GABA/benzodiazepine receptor complex in the aged rat brain

The GABA-ergic system, known to regulate neural tissue genesis during cortical development, has been postulated to play a role in cerebral aging processes. Using in vivo molecular imaging and voxel-wise quantification, we aimed to assess the effects of aging on the benzodiazepine (BDZ) recognition site of the GABA A receptor. To visualize BDZ site availability, [C-11]-flumazenil microPET acquisitions were conducted in young and old rats. The data were analyzed and region of interest analyses were applied to validate the voxel-wise approach. We observed decreased [C-11]-flumazenil binding in the aged rat brains in comparison with the young control group. More specifically, clusters of reduce…

ER stress in human hepatic cells treated with Efavirenz: Mitochondria again

Background & Aims ER stress is associated with a growing number of liver diseases, including drug-induced hepatotoxicity. The non-nucleoside analogue reverse transcriptase inhibitor Efavirenz, a cornerstone of the multidrug strategy employed to treat HIV1 infection, has been related to the development of various adverse events, including metabolic disturbances and hepatic toxicity, the mechanisms of which remain elusive. Recent evidence has pinpointed a specific mitochondrial effect of Efavirenz in human hepatic cells. This study assesses the induction of ER stress by Efavirenz in the same model and the implication of mitochondria in this process. Methods Primary human hepatocytes and Hep3B…

Relationship between PMN-endothelium interactions, ROS production and Beclin-1 in type 2 diabetes.

Type 2 diabetes is closely related to oxidative stress and cardiovascular diseases. In this study, we hypothesized that polymorphonuclear leukocytes (PMN)-endothelium interactions and autophagy are associated. We evaluated PMN-endothelial interactions, ROS production and autophagy parameters in 47 type 2 diabetic patients and 57 control subjects. PMNs from type 2 diabetic patients exhibited slower rolling velocity (p < 0.001), higher rolling flux (p < 0.001) and adhesion (p < 0.001) in parallel to higher levels of total (p < 0.05) and mitochondrial ROS (p < 0.05). When the protein expression of autophagy markers was analysed, an increase of Beclin-1 (p < 0.05), LC3I (p < 0.05), LC3II (p < 0…

Evidence for a relationship between mitochondrial Complex I activity and mitochondrial aldehyde dehydrogenase during nitroglycerin tolerance: effects of mitochondrial antioxidants.

The medical use of nitroglycerin (GTN) is limited by patient tolerance. The present study evaluated the role of mitochondrial Complex I in GIN biotransformation and the therapeutic effect of mitochondrial antioxidants. The development of GIN tolerance (in rat and human vessels) produced a decrease in mitochondrial 02 consumption. Co-incubation with the mitochondria-targeted antioxidant mitoquinone (MQ 10(-6) mol/L) or with glutathione ester (GEE, 10(-4) mol/L) blocked GTN tolerance and the effects of GTN on mitochondrial respiration and aldehyde dehydrogenase 2 (ALDH-2) activity. Biotransformation of GTN depended on the mitochondria being functionally active, particularly mitochondrial Comp…

Inhibition of Mitochondrial Function by Efavirenz Increases Lipid Content in Hepatic Cells

Efavirenz (EFV) is a non-nucleoside reverse transcriptase inhibitor (NNRTI) widely used in human immunodeficiency virus (HIV) infection therapy. It has been associated with hepatotoxic effects and alterations in lipid and body fat composition. Given the importance of the liver in lipid regulation, we have evaluated the effects of clinically used concentrations of EFV on the mitochondria and lipid metabolism of human hepatic cells in vitro. Mitochondrial function was rapidly undermined by EFV to an extent that varied with the concentration employed; in particular, respiration and intracellular adenosine triphosphate (ATP) levels were reduced whereas reactive oxygen species (ROS) production i…

Low testosterone levels are related to oxidative stress, mitochondrial dysfunction and altered subclinical atherosclerotic markers in type 2 diabetic male patients

Abstract Introduction Low testosterone levels in men are associated with type 2 diabetes and cardiovascular risk. However, the role of testosterone in mitochondrial function and leukocyte-endothelium interactions is unknown. Our aim was to evaluate the relationship between testosterone levels, metabolic parameters, oxidative stress, mitochondrial function, inflammation and leukocyte-endothelium interactions in type 2 diabetic patients. Materials and methods The study was performed in 280 male type 2 diabetic patients and 50 control subjects. Anthropometric and metabolic parameters, testosterone levels, reactive oxygen species (ROS) production, mitochondrial membrane potential, TNFα, adhesio…

The SGLT2 Inhibitor Empagliflozin Ameliorates the Inflammatory Profile in Type 2 Diabetic Patients and Promotes an Antioxidant Response in Leukocytes

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Mitochondrial DNA Haplogroup JT is Related to Impaired Glycaemic Control and Renal Function in Type 2 Diabetic Patients

The association between mitochondrial DNA (mtDNA) haplogroup and risk of type 2 diabetes (T2D) is undetermined and controversial. This study aims to evaluate the impact of the main mtDNA haplogroups on glycaemic control and renal function in a Spanish population of 303 T2D patients and 153 healthy controls. Anthropometrical and metabolic parameters were assessed and mtDNA haplogroup was determined in each individual. Distribution of the different haplogroups was similar in diabetic and healthy populations and, as expected, T2D patients showed poorer glycaemic control and renal function than controls. T2D patients belonging to the JT haplogroup (polymorphism m.4216T&gt

Does Metformin Modulate Mitochondrial Dynamics and Function in Type 2 Diabetic Patients?

Metformin is an effective drug against type 2 diabetes (T2D), a pathogenesis in which mitochondrial dysfunction is one of the main players. Thus, our first aim was to describe the effect of metform...

The HIF1α-PFKFB3 Pathway: A Key Player in Diabetic Retinopathy

Abstract Diabetic retinopathy (DR) is the leading cause of blindness for adults in developed countries. Both microvasculopathy and neurodegeneration are implicated in mechanisms of DR development, with neuronal impairment preceding microvascular abnormalities, which is often underappreciated in the clinic. Most current therapeutic strategies, including anti-vascular endothelial growth factor (anti-VEGF)-antibodies, aim at treating the advanced stages (diabetic macular edema and proliferative diabetic retinopathy) and fail to target the neuronal deterioration. Hence, new therapeutic approach(es) intended to address both vascular and neuronal impairment are urgently needed. The hypoxia-induci…

Low intestinal cholesterol absorption is associated with a reduced efficacy of phytosterol esters as hypolipemic agents in patients with metabolic syndrome

Summary Background & aims Phytosterols (PS) lower LDLc, but their effect on metabolic syndrome (MetS) remains unknown. We evaluated whether low-fat milk enriched with PS improves cardiovascular risk factors in these patients. Methods A randomised parallel trial employing 24 moderate-hypercholesterolaemic MetS patients and consisting of two 3-month intervention phases. After a 3-month healthy diet, patients were divided into two intervention groups: diet (n = 10) and diet + PS (n = 14) (2 g/day). A control group of 24 moderate-hypercholesterolaemic patients without MetS (matched in age and BMI) underwent the same procedure. Results Neither dietary intervention nor enrichment of PS induced an…

Autophagy

In 2008, we published the first set of guidelines for standardizing research in autophagy. Since then, this topic has received increasing attention, and many scientists have entered the field. Our knowledge base and relevant new technologies have also been expanding. Thus, it is important to formulate on a regular basis updated guidelines for monitoring autophagy in different organisms. Despite numerous reviews, there continues to be confusion regarding acceptable methods to evaluate autophagy, especially in multicellular eukaryotes. Here, we present a set of guidelines for investigators to select and interpret methods to examine autophagy and related processes, and for reviewers to provide…

Downregulation of miR-31 in Diabetic Nephropathy and its Relationship with Inflammation

Background/Aims: There is a lack of reliable biological markers for the early diagnosis of diabetic nephropathy (DN) during type 2 diabetes. In this pilot study we aim to assess whether miR-31 levels are modulated by the presence of DN and whether the expression of this miRNA is related to leukocyte-endothelial interactions and inflammation. Methods: Thirty-one T2D patients were enrolled in this pilot study; 18 with no diabetic complications and 13 with diabetic nephropathy. 24 non-diabetic subjects and 13 T2D patients with retinopathy (absent of other complications) were included to test the specificity of miR-31. Following anthropometric and biochemical evaluation, serum miR-31 levels wer…

Is Autophagy Altered in the Leukocytes of Type 2 Diabetic Patients?

It is unknown whether autophagy is altered in the leukocytes of type 2 diabetes (T2D) patients and whether oxidative and endoplasmic reticulum (ER) stresses regulate this mechanism. We studied anthropometric and metabolic parameters and evaluated oxidative stress, chromatin condensation, ER stress, and autophagy parameters in leukocytes of 103 T2D patients versus 109 sex- and age-matched controls. Patients showed increases in glucose, insulin, homeostasis model assessment of insulin resistance, and glycated hemoglobin (HbA1c) compared with controls (p < 0.001). Leukocytes displayed enhanced total and mitochondrial reactive oxygen species (ROS), reduced mitochondrial mass, and increased chro…

Toxicological properties of two fluorescent carbon quantum dots with onion ring morphology and their usefulness as bioimaging agents

In the present work, two carbon quantum dots with onion ring morphology, C-NOR and C-NOR(Eu) with an average size of 40 nm differing in the absence or presence of Eu3+ as Lewis acids during their preparation were synthesized and fully characterized by several techniques. These nanoparticles can be internalized into human HeLa and Hep3B carcinoma cells where they exhibit interesting photoluminescent properties, in the same manner as in solution, confirming their utility as bioimaging agents. To address this possibility, a complete in vitro toxicological study has been performed here. Viability, proliferation, apoptosis and oxidative stress assessments upon limited or continuous exposure were…

The mitochondrial antioxidant SS-31 increases SIRT1 levels and ameliorates inflammation, oxidative stress and leukocyte-endothelium interactions in type 2 diabetes

AbstractThere is growing focus on mitochondrial impairment and cardiovascular diseases (CVD) in type 2 diabetes (T2D), and the development of novel therapeutic strategies in this context. It is unknown whether mitochondrial-targeting antioxidants such as SS-31 protect sufficiently against oxidative damage in diabetes. We aimed to evaluate if SS-31 modulates SIRT1 levels and ameliorates leukocyte-endothelium interactions, oxidative stress and inflammation in T2D patients. Anthropometric and metabolic parameters were studied in 51 T2D patients and 57 controls. Production of mitochondrial reactive oxygen species (ROS), mitochondrial membrane potential, glutathione content, leukocyte-endotheliu…

Effect of Non-Surgical Periodontal Treatment on Oxidative Stress Markers in Leukocytes and Their Interaction with the Endothelium in Obese Subjects with Periodontitis: A Pilot Study

Aim: The primary objective of this pilot study was to evaluate the effect of non-surgical periodontal treatment. The secondary aim was to evaluate the effect of dietary therapy on both parameters of oxidative stress in leukocytes and leukocyte-endothelial cell interactions in an obese population. Methods: This was a pilot study with a before-and-after design. Forty-nine obese subjects with periodontitis were randomized by means of the minimization method and assigned to one of two groups, one of which underwent dietary therapy while the other did not. All the subjects underwent non-surgical periodontal treatment. We determined periodontal, inflammatory and oxidative stress parameters&mdash