C-type natriuretic peptide stimulates chicken myoblast differentiation through NPRB/NPRC receptors and metabolism pathway

Skeletal muscle development is closely related with the amount of meat production and its quality in chickens. Natriuretic peptides(NPs) play an important role in myotube formation and fat oxidation of skeletal muscle in animals. The effect of C-type natriuretic peptide(CNP), an important member of the NPs, and its underlying molecular mechanisms in skeletal muscle are incompletely understood. Treatment of myoblasts with CNP led to enhanced proliferation/differentiation and significantly upregulated(P<0.05) m RNA expression of the CNP receptors natriuretic peptide receptor B(NPRB) and the clearance receptor C(NPRC). In cells exposed to CNP, 142 differentially expressed genes(84 up-regulation and 58 down-regulation)(P<0.05) were identified by RNA-sequencing compared with those in control cells. Sixteen genes were significantly enriched(P<0.05) in the metabolic pathway, and six of them(phospholipase C β4, phospholipase C β2, phosphoglycerate mutase 1, creatine kinase B, peroxiredoxin 6 and CD38) were closely related to skeletal muscle development and differentially expressed. In conclusion, CNP stimulated differentiation of myoblasts by upregulating expression of the NPRB and NPRC receptors and enriching key genes in the metabolic pathway.

Bile acids and their receptors: Potential therapeutic targets in inflammatory bowel disease

Chronic and recurrent inflammatory disorders of the gastrointestinal tract caused by a complex interplay between genetics and intestinal dysbiosis are called inflammatory bowel disease.As a result of the interaction between the liver and the gut microbiota,bile acids are an atypical class of steroids produced in mammals and traditionally known for their function in food absorption.With the development of genomics and metabolomics,more and more data suggest that the pathophysiological mechanisms of inflammatory bowel disease are regulated by bile acids and their receptors.Bile acids operate as signalling molecules by activating a variety of bile acid receptors that impact intestinal flora,epithelial barrier function,and intestinal immunology.Inflammatory bowel disease can be treated in new ways by using these potential molecules.This paper mainly discusses the increasing function of bile acids and their receptors in inflammatory bowel disease and their prospective therapeutic applications.In addition,we explore bile acid metabolism and the interaction of bile acids and the gut microbiota.

Role of peroxisome proliferator-activated receptors gene polymorphisms in type 2 diabetes and metabolic syndrome

Metabolic syndrome(MetS) and type 2 diabetes mellitus(T2DM) are the serious public health problems worldwide.Moreover,it is estimated that MetS patients have about five-fold greater risk of the T2 DM development compared with people without the syndrome.Peroxisome proliferator-activated receptors are a subgroup of the nuclear hormone receptor superfamily of ligand-activated transcription factors which play an important role in the pathogenesis of MetS and T2 DM.All three members of the peroxisome proliferator-activated receptor(PPAR) nuclear receptor subfamily,PPARα,PPARp/5 and PPARγ are critical in regulating insulin sensitivity,adipogenesis,lipid metabolism,and blood pressure.Recently,more and more studies indicated that the gene polymorphism of PPARs,such as Leu^(162)Val and Val^(227)Ala of PPARα,+294T> C of PPARβ/δ,Pro^(12)Ala and C1431 T of PPARγ,are significantly associated with the onset and progressing of MetS and T2 DM in different population worldwide.Furthermore,a large body of evidence demonstrated that the glucose metabolism and lipid metabolism were influenced by gene-gene interaction among PPARs genes.However,given the complexity pathogenesis of metabolic disease,it is unlikely that genetic variation of a single locus would provide an adequate explanation of inter-individual differences which results in diverse clinical syndromes.Thus,gene-gene interactions and gene-environment interactions associated with T2 DM and MetS need future comprehensive studies.

Effect of Marine Collagen Peptides on Markers of Metabolic Nuclear Receptors in Type 2 Diabetic Patients with/without Hypertension

Objective To explore Effects of marine collagen peptides （MCPs） on markers of metablic nuclear receptors, i.e peroxisome proliferator-activated receptor （PPARs）, liver X receptor （LXRs） and farnesoid X receptor （FXRs） in type 2 diabetic patients with/without hypertension. Method Study population consisted of 200 type 2 diabetic patients with/without hypertension and 50 healthy subjects, all of whom were randomly assigned to MCPs-treated diabetics （n=50）, placebo-treated diabetics （n=50）, MCPs-treated diabetics with hypertension （n=50）, placebo-treated diabetics with hypertension （n=50）, and healthy controls （n=50）. MCPs or placebo （water-soluble starch） were given daily before breakfast and bedtime over three months. Levels of free fatty acid, cytochrome P450, leptin, resistin, adiponectin, bradykinin, NO, and Prostacyclin were determined before intervention, and 1.5 months, and 3 months after intervention. Hypoglycemia and the endpoint events during the study were recorded and compared among the study groups. Result At the end of the study period, MCPs-treated patients showed marked improvement compared with patients receiving placebo. The protection exerted by MCPs seemed more profound in diabetics than in diabetics with hypertension. In particular, after MCPs intervention, levels of free fatty acid, hs-CRP, resistin, Prostacyclin decreased significantly in diabetics and tended to decrease in diabetic and hypertensive patients whereas levels of cytochrome P450, leptin, NO tended to decrease in diabetics with/without hypertension. Meanwhile, levels of adiponectin and bradykinin rose markedly in diabetics following MCPs administration. Conclusion MCPs could offer protection against diabetes and hypertension by affecting levels of molecules involved in diabetic and hypertensive pathogenesis. Regulation on metabolic nuclear receptors by MCPs may be the possible underlying mechanism for its observed effects in the study. Further study into its action may shed light on development of new drugs based on bioactive peptides from marine sources.

METABOLIC KINETICS OF BRAIN MUSCARINIC CHOLINERGIC RECEPTORS IN NORMAL AND HYPOTHYROID MICE

A technique for studying in vivo the production rate and turnover rate constant of mouse brain M-receptors was established. A single injection of 25 mg / kg of Benzilylcholine Mustard to living mice resulted in 90 % irreversible block of brain M-receptors. The time course of the receptor density was then monitored by 3H-QNB binding assay and the production rate and turnover rate constant were calculated from the time course curve with a computer program. It was found that in normal mice the turnover rate constant was about 0.035 h-1 (half-life was about 20 h) and the production rate was 30-42 fmol / (h ·mg protein). Parallel experiments revealed a significant slow down of the turnover of brain M-receptors in hypothyroid mice (turnover rate constant was 0.0257±0.0012 h-1 in hypothyroid vs. 0.0356±0.0021 h-1 in normal) while the production rate was not changed significantly. The results suggest that thyroid hormones have a regulatory action on the turnover of brain M-receptors and the elevation of brain M-receptor density together with slow down of the turnover of brain M- receptors is probably one of the important mechanisms relevant to the brain dysfunction in hypothyroidism.

Role of peroxisome proliferators-activated receptors in the pathogenesis and treatment of nonalcoholic fatty liver disease

Nonalcoholic fatty liver disease （NAFLD） is highly prevalent and can result in nonalcoholic steatohepatitis （NASH） and progressive liver disease including cirrhosis and hepatocellular carcinoma. A growing body of literature implicates the peroxisome proliferators- activated receptors （PPARs） in the pathogenesis and treatment of NAFLD. These nuclear hormone receptors impact on hepatic triglyceride accumulation and insulin resistance. The aim of this review is to describe the data linking PPARα and PPART to NAFLD/NASH and to discuss the use of PPAR ligands for the treatment of NASH.

Thyroid hormones and thyroid hormone receptors: Effects of thyromimetics on reverse cholesterol transport

Reverse cholesterol transport (RCT) is a complex process which transfers cholesterol from peripheral cells to the liver for subsequent elimination from the body via feces. Thyroid hormones (THs) affect growth, develop- ment, and metabolism in almost all tissues. THs exert their actions by binding to thyroid hormone receptors (TRs). There are two major subtypes of TRs, TRα and TRβ, and several isoforms (e.g. TRα1, TRα2, TRβ1, and TRβ2). Activation of TRα1 affects heart rate, whereas activation of TRβ1 has positive effects on lipid and lipoprotein metabolism. Consequently, particular interest has been focused on the development of thyromimetic compounds targeting TRβ1, not only because of their ability to lower plasma cholesterol but also due their ability to stimulate RCT, at least in pre-clinical models. In this review we focus on THs, TRs, and on the effects of TRβ1-modulating thyromimetics on RCT in various animal models and in humans.

G protein-coupled receptors as potential targets for nonalcoholic fatty liver disease treatment

Nonalcoholic fatty liver disease(NAFLD)is a broad-spectrum disease,ranging from simple hepatic steatosis to nonalcoholic steatohepatitis,which can progress to cirrhosis and liver cancer.Abnormal hepatic lipid accumulation is the major manifestation of this disease,and lipotoxicity promotes NAFLD progression.In addition,intermediate metabolites such as succinate can stimulate the activation of hepatic stellate cells to produce extracellular matrix proteins,resulting in progression of NAFLD to fibrosis and even cirrhosis.G protein-coupled receptors(GPCRs)have been shown to play essential roles in metabolic disorders,such as NAFLD and obesity,through their function as receptors for bile acids and free fatty acids.In addition,GPCRs link gut microbiota-mediated connections in a variety of diseases,such as intestinal diseases,hepatic steatosis,diabetes,and cardiovascular diseases.The latest findings show that gut microbiota-derived acetate contributes to liver lipogenesis by converting dietary fructose into hepatic acetyl-CoA and fatty acids.GPCR agonists,including peptides and natural products like docosahexaenoic acid,have been applied to investigate their role in liver diseases.Therapies such as probiotics and GPCR agonists may be applied to modulate GPCR function to ameliorate liver metabolism syndrome.This review summarizes the current findings regarding the role of GPCRs in the development and progression of NAFLD and describes some preclinical and clinical studies of GPCR-mediated treatment.Overall,understanding GPCR-mediated signaling in liver disease may provide new therapeutic options for NAFLD.

An innovative approach for the treatment of Alzheimer's disease: the role of peroxisome proliferator-activated receptors and their ligands in development of alternative therapeutic interventions

Alzheimer＇s disease is a multifactorial pathology, for which no cure is currently available. Nowadays, researchers are moving towards a new hypothesis of the onset of the illness, linking it to a metabolic impairment, q-his innovative approach will lead to the identification of new targets for the preparation of new effective drugs. Peroxisome proliferator-activated receptors and their ligands are the ideal candidates to reach the necessary breakthrough to defeat this complicate disease.

GLP-1 receptor agonists and myocardial metabolism in atrial fibrillation

Atrial fibrillation(AF)is the most common cardiac arrhythmia.Many medical conditions,including hypertension,diabetes,obesity,sleep apnea,and heart failure(HF),increase the risk for AF.Cardiomyocytes have unique metabolic characteristics to maintain adenosine triphosphate production.Significant changes occur in myocardial metabolism in AF.Glucagon-like peptide-1 receptor agonists(GLP-1RAs)have been used to control blood glucose fluctuations and weight in the treatment of type 2 diabetes mellitus(T2DM)and obesity.GLP-1RAs have also been shown to reduce oxidative stress,inflammation,autonomic nervous system modulation,and mitochondrial function.This article reviews the changes in metabolic characteristics in cardiomyocytes in AF.Although the clinical trial outcomes are unsatisfactory,the findings demonstrate that GLP-1 RAs can improve myocardial metabolism in the presence of various risk factors,lowering the incidence of AF.

Xenobiotic receptors in mediating the effect of sepsis on drug metabolism

Sepsis is an infection-induced systemic inflammatory syndrome.The immune response in sepsis is characterized by the activation of both proinflammatory and anti-inflammatory pathways.When sepsis occurs,the expression and activity of many inflammatory cytokines are markedly affected.Xenobiotic receptors are chemical-sensing transcription factors that play essential roles in the transcriptional regulation of drug-metabolizing enzymes(DMEs).Xenobiotic receptors mediate the functional crosstalk between sepsis and drug metabolism because the inflammatory cytokines released during sepsis can affect the expression and activity of xenobiotic receptors and thus impact the expression and activity of DMEs.Xenobiotic receptors in turn may affect the clinical outcomes of sepsis.Thisreview focuses on the sepsis-induced inflammatory response and xenobiotic receptors such as pregnane X receptor(PXR),aryl hydrocarbon receptor(AHR),glucocorticoid receptor(GR),and constitutive androstane receptor(CAR),DMEs such as CYP1A,CYP2B6,CYP2C9,and CYP3A4,and drug transporters such as p-glycoprotein(P-gp),and multidrug resistance-associated protein(MRPs)that are affected by sepsis.Understanding the xenobiotic receptor-mediated effect of sepsis on drug metabolism will help to improve the safe use of drugs in sepsis patients and the development of new xenobiotic receptor-based therapeutic strategies for sepsis.

RARRES2's impact on lipid metabolism in triplenegative breast cancer:a pathway to brain metastasis

Breast cancer brain metastasis(BCBrM)is a crucial and hard area of research which guarantees an urgent need to understand the underlying molecular mechanisms.A recent study by Li et al.[1]published in Military Medical Research investigated the role of retinoic acid receptor responder 2(RARRES2)in regulating lipid metabolism in BCBrM,highlighting the clinical relevance of alterations in lipid metabolites,such as phosphatidylcholine(PC)and triacylglycerols(TAGs),by RARRES2 through the modulation of phosphatase and tensin homologue(PTEN)-mammalian target of rapamycin(mTOR)-sterol regulatory element-binding protein 1(SREBP1)signaling pathway.This commentary aims to elaborate on the key findings and their relevance to the field.

Targeting nuclear receptors for NASH/MASH:From bench to bedside

The onset of metabolic dysfunction-associated steatohepatitis(MASH)or non-alcoholic steatohepatitis(NASH)represents a tipping point leading to liver injury and subsequent hepatic complications in the natural progression of what is now termed metabolic dysfunction-associated steatotic liver diseases(MASLD),formerly known as non-alcoholic fatty liver disease(NAFLD).With no pharmacological treat-ment currently available for MASH/NASH,the race is on to develop drugs targeting multiple facets of hepatic metabolism,inflammation,and pro-fibrotic events,which are major drivers of MASH.Nuclear receptors(NRs)regulate genomic transcription upon binding to lipophilic ligands and govern multiple aspects of liver metabolism and inflammation.Ligands of NRs may include hormones,lipids,bile acids,and synthetic ligands,which upon binding to NRs regulate the transcriptional activities of target genes.NR ligands are presently the most promising drug candidates expected to receive approval from the United States Food and Drug Administration as a pharmacological treatment for MASH.This review aims to cover the current understanding of NRs,including nuclear hormone receptors,non-steroid hormone receptors,circadian NRs,and orphan NRs,which are currently undergoing clinical trials for MASH treatment,along with NRs that have shown promising results in preclinical studies.

Role of incretins and glucagon receptor agonists in metabolic dysfunction-associated steatotic liver disease:Opportunities and challenges

Metabolic dysfunction-associated steatotic liver disease(MASLD)has become the most common chronic liver disease worldwide,paralleling the rising pandemic of obesity and type 2 diabetes.Due to the growing global health burden and com-plex pathogenesis of MASLD,a multifaceted and innovative therapeutic approach is needed.Incretin receptor agonists,which were initially developed for diabetes management,have emerged as promising candidates for MASLD treatment.This review describes the pathophysiological mechanisms and action sites of three major classes of incretin/glucagon receptor agonists:glucagon-like peptide-1 receptor agonists,glucose-dependent insulinotropic polypeptide receptor agonists,and glucagon receptor agonists.Incretins and glucagon directly or indirectly impact various organs,including the liver,brain,pancreas,gastro-intestinal tract,and adipose tissue.Thus,these agents significantly improve glycemic control and weight management and mitigate MASLD pathogenesis.Importantly,this study provides a summary of clinical trials analyzing the effect-iveness and safety of incretin receptor agonists in MASLD management and provides an in-depth analysis highlighting their beneficial effects on improving liver function,hepatic steatosis,and intrahepatic inflammation.There are emerging challenges associated with the use of these medications in the real world,particularly adverse events,drug-drug interactions,and barriers to access,which are discussed in detail.Additionally,this review highlights the evolving role of incretin receptor agonists in MASLD management and suggests future research directions.

Liver as a new target organ in Alzheimer's disease:insight from cholesterol metabolism and its role in amyloid-beta clearance

Alzheimer's disease,the primary cause of dementia,is characterized by neuropathologies,such as amyloid plaques,synaptic and neuronal degeneration,and neurofibrillary tangles.Although amyloid plaques are the primary characteristic of Alzheimer's disease in the central nervous system and peripheral organs,targeting amyloid-beta clearance in the central nervous system has shown limited clinical efficacy in Alzheimer's disease treatment.Metabolic abnormalities are commonly observed in patients with Alzheimer's disease.The liver is the primary peripheral organ involved in amyloid-beta metabolism,playing a crucial role in the pathophysiology of Alzheimer's disease.Notably,impaired cholesterol metabolism in the liver may exacerbate the development of Alzheimer's disease.In this review,we explore the underlying causes of Alzheimer's disease and elucidate the role of the liver in amyloid-beta clearance and cholesterol metabolism.Furthermore,we propose that restoring normal cholesterol metabolism in the liver could represent a promising therapeutic strategy for addressing Alzheimer's disease.

Microbial transformations of bile acids and their receptors in the regulation of metabolic dysfunction-associated steatotic liver disease

Bile acids(BAs)play important roles in the digestion of dietary fats and molecular signal transduction,and modulation of the BA composition usually affects the progression of metabolic diseases.While the liver produces primary BAs,the gut microbiota modifies these products into various forms that greatly increase their diversity and biological functions.Mechanistically,BAs can regulate their own metabolism and transport as well as other key aspects of metabolic processes via dedicated BA receptors.Disruption of BA transport and homeostasis leads to the progression of liver diseases,including metabolic dysfunction-associated steatotic liver disease(MASLD)and hepatocellular carcinoma(HCC).Here,we summarize the microbial transformations of BAs and their downstream signaling in the development of metabolic diseases and present new insights into novel therapeutic strategies targeting BA pathways that may contribute to these diseases.

Atypical functions of xenobiotic receptors in lipid and glucose metabolism

Xenobiotic receptors are traditionally defined as xenobiotic chemical-sensing receptors,the activation of which transcriptionally regulates the expression of enzymes and transporters involved in the metabolism and disposition of xenobiotics.Emerging evidence suggests that“xenobiotic receptors”also have diverse endobiotic functions,including their effects on lipid metabolism and energy metabolism.Dyslipidemia is a major risk factor for cardiovascular disease,diabetes,obesity,metabolic syndrome,stroke,nonalcoholic fatty liver disease(NAFLD),and nonalcoholic steatohepatitis(NASH).Understanding the molecular mechanism by which transcriptional factors,including the xenobiotic receptors,regulate lipid homeostasis will help to develop preventive and therapeutic approaches.This review describes recent advances in our understanding the atypical roles of three xenobiotic receptors:aryl hydrocarbon receptor(AhR),pregnane X receptor(PXR),and constitutive androstane receptor(CAR),in metabolic disorders,with a particular focus on their effects on lipid and glucose metabolism.Collectively,the literatures suggest the potential values of AhR,PXR and CAR as therapeutic targets for the treatment of NAFLD,NASH,obesity and diabetes,and cardiovascular diseases.

Peroxisome proliferator-activated receptor agonists:A new hope towards the management of alcoholic liver disease

In this editorial,we examine a paper by Koizumi et al,on the role of peroxisome proliferator-activated receptor(PPAR)agonists in alcoholic liver disease(ALD).The study determined whether elafibranor protected the intestinal barrier and reduced liver fibrosis in a mouse model of ALD.The study also underlines the role of PPARs in intestinal barrier function and lipid homeostasis,which are both affected by ALD.Effective therapies are necessary for ALD because it is a critical health issue that affects people worldwide.This editorial analyzes the possibility of PPAR agonists as treatments for ALD.As key factors of inflammation and metabolism,PPARs offer multiple methods for managing the complex etiology of ALD.We assess the abilities of PPARα,PPARγ,and PPARβ/δagonists to prevent steatosis,inflammation,and fibrosis due to liver diseases.Recent research carried out in preclinical and clinical settings has shown that PPAR agonists can reduce the severity of liver disease.This editorial discusses the data analyzed and the obstacles,advantages,and mechanisms of action of PPAR agonists for ALD.Further research is needed to understand the efficacy,safety,and mechanisms of PPAR agonists for treating ALD.

Regulation of bone metabolism mediated byβ-adrenergic receptor and its clinical application

Recent studies have confirmed thatβ-adrenergic receptors(β-ARs)are expressed on the surface of osteoblasts and osteoclasts,and that the sympathetic nervous system can regulate bone metabolism by activating them.β-AR blockers(BBs)are commonly used in the treatment of cardiovascular diseases in the elderly.It is important to investigate whether BBs have a beneficial effect on bone metabolism in the treatment of cardiovascular diseases,so as to expand their clinical application.This article reviews the effects of BB on bone metabolism and the progress of clinical research.

Impact of obese levels on the hepatic expression of nuclear receptors and drug-metabolizing enzymes in adult and offspring mice

The prevalence of obesity-associated conditions raises new challenges in clinical medication.Although altered expression of drug-metabolizing enzymes(DMEs)has been shown in obesity,the impacts of obese levels(overweight,obesity,and severe obesity)on the expression of DMEs have not been elucidated.Especially,limited information is available on whether parental obese levels affect ontogenic expression of DMEs in children.Here,a high-fat diet(HFD)and three feeding durations were used to mimic different obese levels in C57BL/6 mice.The hepatic expression of five nuclear receptors(NRs)and nine DMEs was examined.In general,a trend of induced expression of NRs and DMEs(except for Cyp2c29 and 3a11)was observed in HFD groups compared to low-fat diet(LFD)groups.Differentialeffects of HFD on the hepatic expression of DMEs were found in adult mice at different obese levels.Family-based dietary style of an HFD altered the ontogenic expression of DMEs in the offspring older than 15 days.Furthermore,obese levels of parental mice affected the hepatic expression of DMEs in offspring.Overall,the results indicate that obese levels affected expression of the DMEs in adult individuals and that of their children.Drug dosage might need to be optimized based on the obese levels.