Search results for "Amino Acids"
showing 10 items of 1781 documents
On-demand autophagic network adaptations upon limited lipid availability
2020
The de novo synthesis of autophagic vesicles is strongly dependent on sufficient lipid supply. Recently, the RAB GTPase RAB18 was shown to affect autophagy by mediating fatty acid release from lipid droplets, which are lipid sources for autophagosome formation. The stable loss of RAB18 interfered with fatty acid release from the lipid reservoirs and provoked autophagy network adaptations aiming to maintain autophagic activity under lipid limiting conditions.
Cardiolipin synthesis in brown and beige fat mitochondria is essential for systemic energy homeostasis
2018
Summary Activation of energy expenditure in thermogenic fat is a promising strategy to improve metabolic health, yet the dynamic processes that evoke this response are poorly understood. Here we show that synthesis of the mitochondrial phospholipid cardiolipin is indispensable for stimulating and sustaining thermogenic fat function. Cardiolipin biosynthesis is robustly induced in brown and beige adipose upon cold exposure. Mimicking this response through overexpression of cardiolipin synthase (Crls1) enhances energy consumption in mouse and human adipocytes. Crls1 deficiency in thermogenic adipocytes diminishes inducible mitochondrial uncoupling and elicits a nuclear transcriptional respons…
Cell type specific impact of cannabinoid receptor signaling in somatosensory barrel map formation in mice
2019
Endocannabinoids and their receptors are highly abundant in the developing cerebral cortex and play major roles in early developmental processes, for example, neuronal proliferation, migration, and axonal guidance as well as postnatal plasticity. To investigate the role of the cannabinoid type 1 receptor (CB1) in the formation of sensory maps in the cerebral cortex, the topographic representation of the whiskers in the primary somatosensory cortex (barrel field) of adult mice with different cell type specific genetic deletion of CB1 was studied. A constitutive absence of CB1 (CB1-KO) significantly decreased the total area of the somatosensory cortical map, affecting barrel, and septal areas…
Serum Amino Acid Profiles in Childhood Predict Triglyceride Level in Adulthood: A 7-Year Longitudinal Study in Girls.
2016
AbstractContext:Branched-chain and aromatic amino acids are associated with high risk of developing dyslipidemia and type II diabetes in adults.Objective:This study aimed to examine whether serum amino acid profiles associate with triglyceride concentrations during pubertal growth and predict hypertriglyceridemia in early adulthood.Design:This was a 7.5-year longitudinal study.Setting:The study was conducted at the Health Science Laboratory, University of Jyväskylä.Participants:A total of 396 nondiabetic Finnish girls aged 11.2 ± 0.8 years at the baseline participated in the study.Main Outcome Measures:Body composition was assessed by dual-energy x-ray absorptiometry; serum concentrations o…
Decreased consumption of branched-chain amino acids improves metabolic health
2016
Protein-restricted (PR), high-carbohydrate diets improve metabolic health in rodents, yet the precise dietary components that are responsible for these effects have not been identified. Furthermore, the applicability of these studies to humans is unclear. Here, we demonstrate in a randomized controlled trial that a moderate PR diet also improves markers of metabolic health in humans. Intriguingly, we find that feeding mice a diet specifically reduced in branched-chain amino acids (BCAAs) is sufficient to improve glucose tolerance and body composition equivalently to a PR diet via metabolically distinct pathways. Our results highlight a critical role for dietary quality at the level of amino…
Insulin resistance is associated with altered amino acid metabolism and adipose tissue dysfunction in normoglycemic women
2016
AbstractInsulin resistance is associated adiposity, but the mechanisms are not fully understood. In this study, we aimed to identify early metabolic alterations associated with insulin resistance in normoglycemic women with varying degree of adiposity. One-hundred and ten young and middle-aged women were divided into low and high IR groups based on their median HOMA-IR (0.9 ± 0.4 vs. 2.8 ± 1.2). Body composition was assessed using DXA, skeletal muscle and liver fat by proton magnetic resonance spectroscopy, serum metabolites by nuclear magnetic resonance spectroscopy and adipose tissue and skeletal muscle gene expression by microarrays. High HOMA-IR subjects had higher serum branched-chain …
Circulating exosomes deliver free fatty acids from the bloodstream to cardiac cells: Possible role of CD36
2019
Regulation of circulating free fatty acid (FFA) levels and delivery is crucial to maintain tissue homeostasis. Exosomes are nanomembranous vesicles that are released from diverse cell types and mediate intercellular communication by delivering bioactive molecules. Here, we sought to investigate the uptake of FFAs by circulating exosomes, the delivery of FFA-loaded exosomes to cardiac cells and the possible role of the FFA transporter CD36 in these processes. Circulating exosomes were purified from the serum of healthy donors after an overnight fast (F) or 20 minutes after a high caloric breakfast (postprandial, PP). Western blotting, Immunogold Electron Microscopy and FACS analysis of circu…
Deregulated Lipid Sensing by Intestinal CD36 in Diet-Induced Hyperinsulinemic Obese Mouse Model
2016
International audience; The metabolic syndrome (MetS) greatly increases risk of cardiovascular disease and diabetes and is generally associated with abnormally elevated postprandial triglyceride levels. We evaluated intestinal synthesis of triglyceride-rich lipoproteins (TRL) in a mouse model of the MetS obtained by feeding a palm oil-rich high fat diet (HFD). By contrast to control mice, MetS mice secreted two populations of TRL. If the smaller size population represented 44% of total particles in the beginning of intestinal lipid absorption in MetS mice, it accounted for only 17% after 4 h due to the secretion of larger size TRL. The MetS mice displayed accentuated postprandial hypertrigl…
Sterols in Infant Formulas: A Bioaccessibility Study.
2018
The design of infant formulas (IFs) seeks to resemble human milk (HM) composition and functionality. The fat sources used usually comprise vegetable oil blends to mimic the fatty acid composition of HM and introduce changes in the animal/plant sterol ratio. In contrast, the use of milk fat globule membrane (MFGM)-rich ingredients could improve this aspect by increasing the ratio. The present study evaluates the bioaccessibility (BA) of sterols (cholesterol, desmosterol, brassicasterol, campesterol, stigmasterol, and β-sitosterol) in three IFs (with or without MFGM) using an in vitro digestion method simulating infant conditions. Analytical parameters confirmed the suitability of the method …
HMG-CoA reductase promotes protein prenylation and therefore is indispensible for T-cell survival.
2017
AbstractStatins are a well-established family of drugs that lower cholesterol levels via the competitive inhibition of the enzyme 3-hydroxy-3-methylglutaryl coenzyme A reductase (HMGCR). In addition, the pleiotropic anti-inflammatory effects of statins on T cells make them attractive as therapeutic drugs in T-cell-driven autoimmune disorders. Since statins do not exclusively target HMGCR and thus might have varying effects on different cell types, we generated a new mouse strain allowing for the tissue-specific deletion of HMGCR. Deletion of HMGCR expression in T cells led to a severe decrease in their numbers with the remaining cells displaying an activated phenotype, with an increased pro…