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International Journal of Molecular... Mar 2019Adiponectin regulates metabolism through blood glucose control and fatty acid oxidation, partly mediated by downstream effects of adiponectin signaling in skeletal... (Review)
Review
Adiponectin regulates metabolism through blood glucose control and fatty acid oxidation, partly mediated by downstream effects of adiponectin signaling in skeletal muscle. More recently, skeletal muscle has been identified as a source of adiponectin expression, fueling interest in the role of adiponectin as both a circulating adipokine and a locally expressed paracrine/autocrine factor. In addition to being metabolically responsive, skeletal muscle functional capacity, calcium handling, growth and maintenance, regenerative capacity, and susceptibility to chronic inflammation are all strongly influenced by adiponectin stimulation. Furthermore, physical exercise has clear links to adiponectin expression and circulating concentrations in healthy and diseased populations. Greater physical activity is generally related to higher adiponectin expression while lower adiponectin levels are found in inactive obese, pre-diabetic, and diabetic populations. Exercise training typically restores plasma adiponectin and is associated with improved insulin sensitivity. Thus, the role of adiponectin signaling in skeletal muscle has expanded beyond that of a metabolic regulator to include several aspects of skeletal muscle function and maintenance critical to muscle health, many of which are responsive to, and mediated by, physical exercise.
Topics: Adiponectin; Autophagy; Exercise; Humans; Muscle, Skeletal; Protein Processing, Post-Translational; Regeneration
PubMed: 30934678
DOI: 10.3390/ijms20071528 -
Wiener Medizinische Wochenschrift (1946) Sep 2018Cholesterol is an essential lipid for mammalian cells and its homeostasis is tightly regulated. Disturbance of cellular cholesterol homeostasis is linked to... (Review)
Review
Cholesterol is an essential lipid for mammalian cells and its homeostasis is tightly regulated. Disturbance of cellular cholesterol homeostasis is linked to atherosclerosis and cardiovascular diseases. A central role in the sensing and regulation of cholesterol homeostasis is attributed to the endoplasmic reticulum (ER). This organelle harbours inactive transcription factors, which sense ER cholesterol levels and initiate transcriptional responses after activation and translocation into the nucleus. Thereupon, these responses enable adaption to high or low cellular cholesterol levels. Besides the abovementioned canonical functions, ER stress-induced by metabolic burden-and the resulting unfolded protein response influence cholesterol metabolism relevant to metabolic disorders. This review summarizes basic as well as recent knowledge on the role of the ER in terms of regulation of cholesterol metabolism.
Topics: Animals; Cholesterol; Endoplasmic Reticulum; Endoplasmic Reticulum Stress; Humans; Lipid Metabolism; Unfolded Protein Response
PubMed: 29488036
DOI: 10.1007/s10354-018-0626-2 -
Frontiers in Immunology 2020The interplay between cellular stress and immune response can be variable and sometimes contradictory. The mechanisms by which stress-activated pathways regulate the... (Review)
Review
The interplay between cellular stress and immune response can be variable and sometimes contradictory. The mechanisms by which stress-activated pathways regulate the inflammatory response to a pathogen, in autoimmunity or during cancer progression remain unclear in many aspects, despite our recent knowledge of the signalling and transcriptional pathways involved in these diseases. In this context, over the last decade many studies demonstrated that cholesterol metabolism is an important checkpoint for immune homeostasis and cancer progression. Indeed, cholesterol is actively metabolized and can regulate, through its mobilization and/or production of active derivatives, many aspects of immunity and inflammation. Moreover, accumulation of cholesterol has been described in cancer cells, indicating metabolic addiction. The nuclear receptors liver-X-receptors (LXRs) are important regulators of intracellular cholesterol and lipids homeostasis. They have also key regulatory roles in immune response, as they can regulate inflammation, innate and adaptive immunity. Moreover, activation of LXRs has been reported to affect the proliferation and survival of different cancer cell types that show altered metabolic pathways and accumulation of cholesterol. In this minireview we will give an overview of the recent understandings about the mechanisms through which LXRs regulate inflammation, autoimmunity, and cancer, and the therapeutic potential for future treatment of these diseases through modulation of cholesterol metabolism.
Topics: Adaptive Immunity; Animals; Autoimmunity; Cholesterol; Humans; Immunity, Innate; Inflammation; Lipid Metabolism; Liver X Receptors; Metabolic Networks and Pathways; Neoplasms; Signal Transduction
PubMed: 33224146
DOI: 10.3389/fimmu.2020.584303 -
Free Radical Biology & Medicine Nov 2016Understanding molecular mechanisms that underlie the recent emergence of metabolic diseases such as diabetes and heart failure has revealed the need for a... (Review)
Review
Understanding molecular mechanisms that underlie the recent emergence of metabolic diseases such as diabetes and heart failure has revealed the need for a multi-disciplinary research integrating the key metabolic pathways which change the susceptibility to environmental or pathologic stress. At the physiological level these include the circadian control of metabolism which aligns metabolism with temporal demand. The mitochondria play an important role in integrating the redox signals and metabolic flux in response to the changing activities associated with chronobiology, exercise and diet. At the molecular level this involves dynamic post-translational modifications regulating transcription, metabolism and autophagy. In this review we will discuss different examples of mechanisms which link these processes together. An important pathway capable of linking signaling to metabolism is the post-translational modification of proteins by O-linked N-acetylglucosamine (O-GlcNAc). This is a nutrient regulated protein modification that plays an important role in impaired cellular stress responses. Circadian clocks have also emerged as critical regulators of numerous cardiometabolic processes, including glucose/lipid homeostasis, hormone secretion, redox status and cardiovascular function. Central to these pathways are the response of autophagy, bioenergetics to oxidative stress, regulated by Keap1/Nrf2 and mechanisms of metabolic control. The extension of these ideas to the emerging concept of bioenergetic health will be discussed.
Topics: Acetylglucosamine; Animals; Autophagy; Circadian Clocks; Energy Metabolism; Humans; Kelch-Like ECH-Associated Protein 1; Mitochondria; Oxidation-Reduction; Oxidative Stress; Protein Processing, Post-Translational; Signal Transduction
PubMed: 27242268
DOI: 10.1016/j.freeradbiomed.2016.05.022 -
The Journal of Experimental Biology Mar 2024From bacteria to metazoans, higher density populations have lower per capita metabolic rates than lower density populations. The negative covariance between population...
From bacteria to metazoans, higher density populations have lower per capita metabolic rates than lower density populations. The negative covariance between population density and metabolic rate is thought to represent a form of adaptive metabolic plasticity. A relationship between density and metabolism was actually first noted 100 years ago, and was focused on spermatozoa; even then, it was postulated that adaptive plasticity drove this pattern. Since then, contemporary studies of sperm metabolism specifically assume that sperm concentration has no effect on metabolism and that sperm metabolic rates show no adaptive plasticity. We did a systematic review to estimate the relationship between sperm aerobic metabolism and sperm concentration, for 198 estimates spanning 49 species, from protostomes to humans from 88 studies. We found strong evidence that per capita metabolic rates are concentration dependent: both within and among species, sperm have lower metabolisms in dense ejaculates, but increase their metabolism when diluted. On average, a 10-fold decrease in sperm concentration increased per capita metabolic rate by 35%. Metabolic plasticity in sperm appears to be an adaptive response, whereby sperm maximize their chances of encountering eggs.
Topics: Humans; Male; Semen; Sperm Motility; Spermatozoa; Energy Metabolism
PubMed: 38380562
DOI: 10.1242/jeb.246674 -
Expert Opinion on Drug Metabolism &... Jul 2012The xenobiotic detoxification system, which protects the human body from external chemicals, comprises drug-metabolizing enzymes and transporters whose expressions are... (Review)
Review
INTRODUCTION
The xenobiotic detoxification system, which protects the human body from external chemicals, comprises drug-metabolizing enzymes and transporters whose expressions are regulated by pregnane X receptor (PXR) and the constitutive androstane receptor (CAR). The progress made in a large number of recent studies calls for a timely review to summarize and highlight these key discoveries.
AREAS COVERED
This review summarizes recent advances in elucidating the roles of PXR and CAR in the xenobiotic detoxification system. It also highlights the progress in understanding the regulation of PXR and CAR activity at the post-translational levels, as well as the structural basis for the regulation of these two xenobiotic sensors.
EXPERT OPINION
Future efforts are needed to discover novel agonists and antagonists with species and isoform selectivity, to systematically understand the regulation of PXR and CAR at multiple levels (transcriptional, post-transcriptional and post-translational levels) in response to xenobiotics exposure, and to solve the structures of the full-length receptors, which will be enabled by improved protein expression and purification techniques and approaches. In addition, more efforts will be needed to validate PXR and CAR as disease-related therapeutic targets and thus expand their roles as master xenobiotic sensors.
Topics: Animals; Constitutive Androstane Receptor; Drug Interactions; Gene Expression Regulation; Humans; Inactivation, Metabolic; Ligands; Models, Animal; Pregnane X Receptor; Protein Binding; Protein Processing, Post-Translational; Receptors, Cytoplasmic and Nuclear; Receptors, Steroid; Signal Transduction; Xenobiotics
PubMed: 22554043
DOI: 10.1517/17425255.2012.685237 -
Yakugaku Zasshi : Journal of the... 2017Since more than 70% of clinically used drugs are excreted from the body through metabolic processes, drug metabolism is a key determinant of pharmacokinetics, drug... (Review)
Review
Since more than 70% of clinically used drugs are excreted from the body through metabolic processes, drug metabolism is a key determinant of pharmacokinetics, drug response and drug toxicity. Much progress has been made in understanding drug-drug interactions via the inhibition or induction of cytochrome P450s (P450, CYP), as well as the effects of genetic polymorphisms of P450s on pharmacokinetics, and this has facilitated the progress of optimized pharmacotherapy in the clinic. Now, similar information is needed for non-CYP enzymes, especially concerning Phase I enzymes, based on advanced basic and clinical studies. Recently, it was revealed that post-transcriptional regulation by microRNAs or RNA editing plays a significant role in regulating the expression of drug-metabolizing enzymes, thus conferring variability in the detoxification and metabolic activation of drugs or chemicals. Changes in the expression profile of microRNAs in tissues or body fluids can be a biomarker of drug response and toxicity; therefore, such studies could also be useful for drug repositioning. In addition, microRNAs are involved in pharmacogenetics, because single nucleotide polymorphisms in microRNA binding sites of mRNAs, or microRNAs themselves, may cause changes in gene expression. Some microRNA-related polymorphisms could be biomarkers of the clinical outcome of pharmacotherapy. In this review article, recent progress and future directions for drug metabolism studies are discussed.
Topics: Binding Sites; Cytochrome P-450 Enzyme System; Drug Interactions; Drug Therapy; Drug-Related Side Effects and Adverse Reactions; Humans; Inactivation, Metabolic; MicroRNAs; Pharmaceutical Preparations; Pharmacogenetics; Pharmacokinetics; Polymorphism, Genetic; Polymorphism, Single Nucleotide; RNA Editing; RNA Processing, Post-Transcriptional
PubMed: 28566576
DOI: 10.1248/yakushi.16-00250-5 -
Scientific Reports Feb 2022The aims of the current study, therefore, were to compare (1) free-living MPS and (2) muscle and metabolic adaptations to resistance exercise in South Asian and white...
The aims of the current study, therefore, were to compare (1) free-living MPS and (2) muscle and metabolic adaptations to resistance exercise in South Asian and white European adults. Eighteen South Asian and 16 White European men were enrolled in the study. Free-living muscle protein synthesis was measured at baseline. Muscle strength, body composition, resting metabolic rate, VO and metabolic responses (insulin sensitivity) to a mixed meal were measured at baseline and following 12 weeks of resistance exercise training. Free-living muscle protein synthesis was not different between South Asians (1.48 ± 0.09%/day) and White Europeans (1.59 ± 0.15%/day) (p = 0.522). In response to resistance exercise training there were no differences, between South Asians and White Europeans, muscle mass, lower body strength or insulin sensitivity. However, there were differences between the ethnicities in response to resistance exercise training in body fat, resting carbohydrate and fat metabolism, blood pressure, VO and upper body strength with responses less favourable in South Asians. In this exploratory study there were no differences in muscle protein synthesis or anabolic and metabolic responses to resistance exercise, yet there were less favourable responses in several outcomes. These findings require further investigation.
Topics: Adipose Tissue; Adult; Asia, Southeastern; Asian People; Body Composition; Carbohydrate Metabolism; Europe; Exercise; Humans; Insulin Resistance; Lipid Metabolism; Male; Muscle Proteins; Muscle Strength; Muscle, Skeletal; Resistance Training; White People; Young Adult
PubMed: 35169204
DOI: 10.1038/s41598-022-06446-7 -
Genome Biology Sep 2021Drought is a major environmental disaster that causes crop yield loss worldwide. Metabolites are involved in various environmental stress responses of plants. However,...
BACKGROUND
Drought is a major environmental disaster that causes crop yield loss worldwide. Metabolites are involved in various environmental stress responses of plants. However, the genetic control of metabolomes underlying crop environmental stress adaptation remains elusive.
RESULTS
Here, we perform non-targeted metabolic profiling of leaves for 385 maize natural inbred lines grown under well-watered as well as drought-stressed conditions. A total of 3890 metabolites are identified and 1035 of these are differentially produced between well-watered and drought-stressed conditions, representing effective indicators of maize drought response and tolerance. Genetic dissections reveal the associations between these metabolites and thousands of single-nucleotide polymorphisms (SNPs), which represented 3415 metabolite quantitative trait loci (mQTLs) and 2589 candidate genes. 78.6% of mQTLs (2684/3415) are novel drought-responsive QTLs. The regulatory variants that control the expression of the candidate genes are revealed by expression QTL (eQTL) analysis of the transcriptomes of leaves from 197 maize natural inbred lines. Integrated metabolic and transcriptomic assays identify dozens of environment-specific hub genes and their gene-metabolite regulatory networks. Comprehensive genetic and molecular studies reveal the roles and mechanisms of two hub genes, Bx12 and ZmGLK44, in regulating maize metabolite biosynthesis and drought tolerance.
CONCLUSION
Our studies reveal the first population-level metabolomes in crop drought response and uncover the natural variations and genetic control of these metabolomes underlying crop drought adaptation, demonstrating that multi-omics is a powerful strategy to dissect the genetic mechanisms of crop complex traits.
Topics: Adaptation, Physiological; Benzoxazines; Biosynthetic Pathways; Droughts; Gene Expression Regulation, Plant; Genetic Association Studies; Genetic Variation; Genomics; Glucosides; Metabolic Networks and Pathways; Metabolome; Metabolomics; Molecular Sequence Annotation; Plant Proteins; Quantitative Trait Loci; Tryptophan; Zea mays
PubMed: 34488839
DOI: 10.1186/s13059-021-02481-1 -
Basic & Clinical Pharmacology &... Jan 2007Newer antipsychotics introduced in clinical practice in recent years include clozapine, risperidone, olanzapine, quetiapine, sertindole, ziprasidone, aripiprazole and... (Comparative Study)
Comparative Study Review
Newer antipsychotics introduced in clinical practice in recent years include clozapine, risperidone, olanzapine, quetiapine, sertindole, ziprasidone, aripiprazole and amisulpride. These agents are subject to drug-drug interactions with other psychotropic agents or with medications used in the treatment of concomitant physical illnesses. Most pharmacokinetic interactions with newer antipsychotics occur at the metabolic level and usually involve changes in the activity of the major drug-metabolizing enzymes involved in their biotransformation, i.e. the cytochrome P450 (CYP) monooxygenases and/or uridine diphosphate-glucuronosyltransferases (UGT). Clozapine is metabolized primarily by CYP1A2, with additional contribution by other CYP isoforms. Risperidone is metabolized primarily by CYP2D6 and, to a lesser extent, CYP3A4. Olanzapine undergoes both direct conjugation and CYP1A2-mediated oxidation. Quetiapine is metabolized by CYP3A4, while sertindole and aripiprazole are metabolized by CYP2D6 and CYP3A4. Ziprasidone pathways include aldehyde oxidase-mediated reduction and CYP3A4-mediated oxidation. Amisulpride is primarily excreted in the urine and undergoes relatively little metabolism. While novel antipsychotics are unlikely to interfere with the elimination of other drugs, co-administration of inhibitors or inducers of the major enzymes responsible for their metabolism may modify their plasma concentrations, leading to potentially significant effects. Most documented metabolic interactions involve antidepressant and anti-epileptic drugs. Of a particular clinical significance is the interaction between fluvoxamine, a potent CYP1A2 inhibitor, and clozapine. Differences in the interaction potential among the novel antipsychotics currently available may be predicted based on their metabolic pathways. The clinical relevance of these interactions should be interpreted in relation to the relative width of their therapeutic index. Avoidance of unnecessary polypharmacy, knowledge of the interaction profiles of individual agents, and careful individualization of dosage based on close evaluation of clinical response and, possibly, plasma drug concentrations are essential to prevent and minimize potentially adverse drug interactions in patients receiving newer antipsychotics.
Topics: Antipsychotic Agents; Biological Availability; Biotransformation; Drug Interactions; Drug-Related Side Effects and Adverse Reactions; Humans
PubMed: 17214606
DOI: 10.1111/j.1742-7843.2007.00017.x