Search results for "Phosphorylation"
showing 10 items of 975 documents
Novel noninvasive embryo selection algorithm combining time-lapse morphokinetics and oxidative status of the spent embryo culture medium.
2019
Objective To develop a noninvasive embryo selection algorithm consisting of time-lapse morphokinetics and the oxidative status of the spent embryo culture medium determined using the Thermochemiluminescence (TCL) Analyzer. Design Retrospective cohort. Setting Not applicable. Patient(s) From women participating in the oocyte donation program, data from 505 samples of spent embryo culture media samples from 292 intracytoplasmic sperm injection cycles. Intervention(s) None. Main Outcome Measure(s) Morphokinetic parameters assessed during incubation in the time-lapse system Embryoscope. Oxidative parameters (H1sm, H2sm, and H3sm) from the spent culture medium on day 5 of incubation measured usi…
Mechanisms of action of metformin in type 2 diabetes: Effects on mitochondria and leukocyte-endothelium interactions.
2020
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…
Coffee silverskin extract protects against accelerated aging caused by oxidative agents
2016
Nowadays, coffee beans are almost exclusively used for the preparation of the beverage. The sustainability of coffee production can be achieved introducing new applications for the valorization of coffee by-products. Coffee silverskin is the by-product generated during roasting, and because of its powerful antioxidant capacity, coffee silverskin aqueous extract (CSE) may be used for other applications, such as antiaging cosmetics and dermaceutics. This study aims to contribute to the coffee sector’s sustainability through the application of CSE to preserve skin health. Preclinical data regarding the antiaging properties of CSE employing human keratinocytes and Caenorhabditis elegans are col…
Homocysteine Induces Apoptosis of Human Umbilical Vein Endothelial Cells via Mitochondrial Dysfunction and Endoplasmic Reticulum Stress
2017
Homocysteine- (Hcy-) induced endothelial cell apoptosis has been suggested as a cause of Hcy-dependent vascular injury, while the proposed molecular pathways underlying this process are unclear. In this study, we investigated the adverse effects of Hcy on human umbilical vein endothelial cells (HUVEC) and the underlying mechanisms. Our results demonstrated that moderate-dose Hcy treatment induced HUVEC apoptosis in a time-dependent manner. Furthermore, prolonged Hcy treatment increased the expression of NOX4 and the production of intracellular ROS but decreased the ratio of Bcl-2/Bax and mitochondrial membrane potential (MMP), resulting in the leakage of cytochrome c and activation of caspa…
Cholesterol Hydroxylating Cytochrome P450 46A1: From Mechanisms of Action to Clinical Applications
2021
Cholesterol, an essential component of the brain, and its local metabolism are involved in many neurodegenerative diseases. The blood-brain barrier is impermeable to cholesterol; hence, cholesterol homeostasis in the central nervous system represents a balance betweenin situbiosynthesis and elimination. Cytochrome P450 46A1 (CYP46A1), a central nervous system-specific enzyme, converts cholesterol to 24-hydroxycholesterol, which can freely cross the blood-brain barrier and be degraded in the liver. By the dual action of initiating cholesterol efflux and activating the cholesterol synthesis pathway, CYP46A1 is the key enzyme that ensures brain cholesterol turnover. In humans and mouse models,…
Adult rat myelin enhances axonal outgrowth from neural stem cells.
2018
Axon regeneration after spinal cord injury (SCI) is attenuated by growth inhibitory molecules associated with myelin. We report that rat myelin stimulated the growth of axons emerging from rat neural progenitor cells (NPCs) transplanted into sites of SCI in adult rat recipients. When plated on a myelin substrate, neurite outgrowth from rat NPCs and from human induced pluripotent stem cell (iPSC)-derived neural stem cells (NSCs) was enhanced threefold. In vivo, rat NPCs and human iPSC-derived NSCs extended greater numbers of axons through adult central nervous system white matter than through gray matter and preferentially associated with rat host myelin. Mechanistic investigations excluded …
Targeting the Endoplasmic Reticulum Unfolded Protein Response to Counteract the Oxidative Stress-Induced Endothelial Dysfunction
2017
In endothelial cells, the tight control of the redox environment is essential for the maintenance of vascular homeostasis. The imbalance between ROS production and antioxidant response can induce endothelial dysfunction, the initial event of many cardiovascular diseases. Recent studies have revealed that the endoplasmic reticulum could be a new player in the promotion of the pro- or antioxidative pathways and that in such a modulation, the unfolded protein response (UPR) pathways play an essential role. The UPR consists of a set of conserved signalling pathways evolved to restore the proteostasis during protein misfolding within the endoplasmic reticulum. Although the first outcome of the U…
Overexpression of glucose 6 phosphate dehydrogenase preserves mouse pancreatic beta cells function until late in life.
2021
NAD(P)H donates electrons for reductive biosynthesis and antioxidant defense across all forms of life. Glucose-6- phosphate dehydrogenase (G6PD) is a critical enzyme to provide NADPH. G6PD deficiency is present in more than 400 million people worldwide. This enzymopathy provides protection against malaria but sensitizes cells to oxidative stressors. Oxidative stress has been involved in the pathogenesis of the diabetic complications and several studies have provided evidences of a link between G6PD deficiency and type 2 diabetes (T2D). We hypothesized that a moderate overexpression of G6PD (G6PD-Tg) could protect β-cells from age-associated oxidative stress thus reducing the risk of develop…
Effects of intrinsic aerobic capacity, aging and voluntary running on skeletal muscle sirtuins and heat shock proteins
2016
Aim Sirtuins are proteins that connect energy metabolism, oxidative stress and aging. Expression of heat shock proteins (Hsps) is regulated by heat shock factors (HSFs) in response to various environmental and physiological stresses, such as oxidative stress. Oxidative stress accumulates during aging which makes cells more prone to DNA damage. Although many experimental animal models have been designed to study the effects of knockdown or overexpression of sirtuins, HSFs and Hsps, little is known about how aging per se affects their expression. Here we study the impact of intrinsic aerobic capacity, aging and voluntary exercise on the levels of sirtuins, HSFs and Hsps in skeletal muscle. Me…
Desensitization of cAMP Accumulation via Human β3-Adrenoceptors Expressed in Human Embryonic Kidney Cells by Full, Partial, and Biased Agonists
2019
β3-Adrenoceptors couple not only to cAMP formation but, at least in some cell types, also to alternative signaling pathways such as phosphorylation of extracellular signal-regulated kinase (ERK). β3-Adrenoceptor agonists are used in long-term symptomatic treatment of the overactive bladder syndrome; it is only poorly understood which signaling pathway mediates the clinical response and whether it undergoes agonist-induced desensitization. Therefore, we used human embryonic kidney cells stably transfected with human β3-adrenoceptors to compare coupling of ligands with various degrees of efficacy, including biased agonists, to cAMP formation and ERK phosphorylation, particularly regarding des…