Search results for "ENERGETICS"

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

2016

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 (…

Stem Cell-Derived, microRNA-Carrying Extracellular Vesicles: A Novel Approach to Interfering with Mesangial Cell Collagen Production in a Hyperglycae…

2016

Extracellular vesicles (EVs) that are derived from stem cells are proving to be promising therapeutic options. We herein investigate the therapeutic potential of EVs that have been derived from different stem cell sources, bone-marrow (MSC) and human liver (HLSC), on mesangial cells (MCs) exposed to hyperglycaemia. By expressing a dominant negative STAT5 construct (ΔNSTAT5) in HG-cultured MCs, we have demonstrated that miR-21 expression is under the control of STAT5, which translates into Transforming Growth Factor beta (TGFβ) expression and collagen production. A number of approaches have been used to show that both MSC- and HLSC-derived EVs protect MCs from HG-induced damage via the trans…

Levosimendan protects human hepatocytes from ischemia-reperfusion injury.

2017

Background Ischemia-reperfusion injury (IRI) is a major challenge in liver transplantation. The mitochondrial pathway plays a pivotal role in hepatic IRI. Levosimendan, a calcium channel sensitizer, was shown to attenuate apoptosis after IRI in animal livers. The aim of this study was to investigate the effect of levosimendan on apoptosis in human hepatocytes. Methods Primary human hepatocytes were either exposed to hypoxia or cultured under normoxic conditions. After the hypoxic phase, reoxygenation was implemented and cells were treated with different concentrations of levosimendan (10ng/ml, 100ng/ml, 1000ng/ml). The overall metabolic activity of the cells was measured using 3-(4,5-dimeth…

Bcl-xL knockout attenuates mitochondrial respiration and causes oxidative stress that is compensated by pentose phosphate pathway activity

2017

Bcl-xL is an anti-apoptotic protein that localizes to the outer mitochondrial membrane and influences mitochondrial bioenergetics by controlling Ca2+ influx into mitochondria. Here, we analyzed the effect of mitochondrial Bcl-xL on mitochondrial shape and function in knockout (KO), wild type and rescued mouse embryonic fibroblast cell lines. Mitochondria of KO cells were more fragmented, exhibited a reduced ATP concentration, and reduced oxidative phosphorylation (OXPHOS) suggesting an increased importance of ATP generation by other means. Under steady-state conditions, acidification of the growth medium as a readout for glycolysis was similar, but upon inhibition of ATP synthase with oligo…

Nature lessons: the whitefly bacterial endosymbiont is a minimal amino acid factory with unusual energetics

2016

Reductive genome evolution is a universal phenomenon observed in endosymbiotic bacteria in insects. As the genome reduces its size and irreversibly losses coding genes, the functionalities of the cell system, including the energetics processes, are more restricted. Several energetic pathways can also be lost. How do these reduced metabolic networks sustain the energy needs of the system? Among the bacteria with reduced genomes Candidatus Portiera aleyrodidarum, obligate endosymbiont of whiteflies, represents an extreme case since lacks several key mechanisms for ATP generation. Thus, to analyze the cell energetics in this system, a genome-scale metabolic model of this endosymbiont was const…

Mitochondrial targeting as a novel therapy for stroke

2018

Stroke is a main cause of mortality and morbidity worldwide. Despite the increasing development of innovative treatments for stroke, most are unsuccessful in clinical trials. In recent years, an encouraging strategy for stroke therapy has been identified in stem cells transplantation. In particular, grafting cells and their secretion products are leading with functional recovery in stroke patients by promoting the growth and function of the neurovascular unit – a communication framework between neurons, their supply microvessels along with glial cells – underlying stroke pathology and recovery. Mitochondrial dysfunction has been recently recognized as a hallmark in ischemia/reperfusion neur…

The Unfolded Protein Response Plays a Predominant Homeostatic Role in Response to Mitochondrial Stress in Pancreatic Stellate Cells.

2016

Activated pancreatic stellate cells (PaSC) are key participants in the stroma of pancreatic cancer, secreting extracellular matrix proteins and inflammatory mediators. Tumors are poorly vascularized, creating metabolic stress conditions in cancer and stromal cells that necessitate adaptive homeostatic cellular programs. Activation of autophagy and the endoplasmic reticulum unfolded protein response (UPR) have been described in hepatic stellate cells, but the role of these processes in PaSC responses to metabolic stress is unknown. We reported that the PI3K/mTOR pathway, which AMPK can regulate through multiple inputs, modulates PaSC activation and fibrogenic potential. Here, using primary a…

The Role of the Energetics of Adsorption in Kinetic Studies

1981

Variability in energy expenditure is much greater in males than females

2022

In mammals, trait variation is often reported to be greater among males than females. However, to date, mainly only morphological traits have been studied. Energy expenditure represents the metabolic costs of multiple physical, physiological, and behavioral traits. Energy expenditure could exhibit particularly high greater male variation through a cumulative effect if those traits mostly exhibit greater male variation, or a lack of greater male variation if many of them do not. Sex differences in energy expenditure variation have been little explored. We analyzed a large database on energy expenditure in adult humans (1494 males and 3108 females) to investigate whether humans have evolved s…

Low-intensity exercise stimulates bioenergetics and increases fat oxidation in mitochondria of blood mononuclear cells from sedentary adults.

2020

Aim Exercise training induces adaptations in muscle and other tissue mitochondrial metabolism, dynamics, and oxidative phosphorylation capacity. Mitochondrial fatty acid oxidation was shown to be pivotal for the anti‐inflammatory status of immune cells. We hypothesize that exercise training can exert effects influence mitochondrial fatty acid metabolism in peripheral blood mononuclear cells (PBMCs). The aim was to investigate the effect of exercise on the fatty acid oxidation‐dependent respiration in PBMCs. Design Twelve fasted or fed volunteers first performed incremental‐load exercise tests to exhaustion on a cycle ergometer to determine the optimal workload ensuring maximal health benefi…