Carboxylesterase 2a deletion provokes hepatic steatosis and insulin resistance in mice involving impaired diacylglycerol and lysophosphatidylcholine catabolism

Alisol B alleviates MASLD by activating liver autophagy and fatty acid oxidation via Ces2a

Metabolic dysfunction-associated steatotic liver disease (MASLD) is a prevalent global health issue characterized by excessive fat accumulation in the liver, often linked to obesity and metabolic syndrome. Despite advancements in understanding its pathogenesis, effective therapeutic strategies remain limited. This study investigates the potential of Alisol B, a natural compound from traditional Chinese medicine, in modulating lipid metabolism and autophagy in hepatocytes. We employed a combination of in vivo and in vitro approaches, including mouse models, cell culture assays, and transcriptomic profiling, to evaluate Alisol B's therapeutic efficacy against MASLD and elucidate its underlying mechanisms. Our findings reveal that Alisol B significantly reduces lipid accumulation and enhances fatty acid metabolism by upregulating Ces2a, a key regulator of lipid catabolism, as confirmed by RNA sequencing and Western blot analyses. Additionally, transcriptomic analysis indicates that Alisol B activates critical signaling pathways related to fatty acid metabolism and autophagy, including AMPK signaling. Importantly, in vitro studies demonstrate that Alisol B effectively reduces triglyceride levels in hepatocytes without compromising cell viability. Pharmacological inhibition of Ces2a further underscores its essential role in mediating Alisol B's therapeutic effects. These results suggest that Alisol B holds promise as a novel therapeutic agent for MASLD, warranting further exploration of its clinical applications and potential as a targeted treatment for metabolic disorders.

Exploring the lipid-lowering effects of cinnamic acid and cinnamaldehyde from the perspective of the gut microbiota and metabolites

The increasing incidence and associated metabolic complications pose major challenges in the treatment of hyperlipidaemia. Cinnamon is a food and medicinal resource associated with lipid metabolism, but the mechanism by which its active components, cinnamic acid (CA) and cinnamaldehyde (CM), alleviate hyperlipidaemia remains unclear. Biochemical, pathological, gut microbiota, and metabolomic analyses were performed to investigate the effects of CA and CM on HFD-fed mice and the underlying mechanisms involved. Supplementation with CA and CM reduced body weight, liver, and adipose tissue accumulation in HFD-induced mice; improved glucose and lipid metabolism; and decreased inflammation and oxidative stress levels, with CM showing superior efficacy. Faecal microbiota transplantation confirmed that the therapeutic effect was closely related to core gut bacteria and metabolites. Specifically, CA and CM inhibited the growth of lipid metabolism-related genera (e.g., Turicibacter and Romboutsia) and metabolites (e.g., PC, LysoPCs, prostaglandin E2, and arachidonic acid) while promoting the growth of beneficial genera (e.g., Oscillospiraceae and Colidextribacter) and metabolites (e.g., linoleic acid, phytosphingosine, and stercobilin). Additionally, Spearman's correlation analysis revealed that serum and hepatic lipids, as well as inflammatory factors, were positively correlated with Erysipelatoclostridium, Turicibacter, Eubacterium fissicatena, Enterorhabdus, cervonoyl ethanolamide, and acetoxystachybotrydial acetate, whereas they were negatively correlated with Lachnospiraceae NK4A136, stercobilin, LysoPE (15:0/0:0), and phytosphingosine. In contrast, hepatic oxidative stress markers exhibited the opposite correlation pattern. In conclusion, CA and CM have the potential to regulate the core gut microbiota and metabolites to improve lipid metabolism and decrease related inflammation and oxidative stress levels.

Carboxylesterase 2A gene knockout or enzyme inhibition alleviates steatohepatitis in rats by regulating PPARγ and endoplasmic reticulum stress

Metabolic dysfunction associated steatotic liver disease (MASLD) is a widespread liver disease that progresses from simple steatosis to severe steatohepatitis stage. Despite the recognized importance of carboxylesterase 2 (CES2) in hepatic lipid metabolism, the role of CES2 in hepatic inflammation remains unclear. The rat genome encodes six Ces2 genes and Ces2a shows high expression in the liver and intestine. Lipid metabolism, inflammation, fibrosis, and endoplasmic reticulum (ER) stress were investigated in Ces2a knockout (KO) rats. KO rats showed spontaneous liver lipid accumulation due to increased lipogenesis and reduced fatty acid oxidation. Non-targeted lipidomic analysis revealed enhanced lysophosphatidylcholines (LPCs) and phosphatidylcholines (PCs) in KO rats and increased concentrations of ligands, thus activating the expression of PPARγ. Although there was simple lipid accumulation in the liver of KO rats, Ces2a deficiency showed a significant protective effect against LPS and diet-induced hepatic steatohepatitis by inhibiting ER stress regulated by PPARγ activation. In line with this, treatment with tanshinone IIA, a CES2 inhibitor, significantly alleviated the progression of steatohepatitis induced by the MCD diet. In conclusion, the increased PPARγ expression in Ces2a deficiency may counteract liver inflammation and ER stress despite the presence of simple steatosis. Therefore, CES2 inhibition represents a potential therapeutic approach for steatohepatitis.

Near-infrared fluorescence imaging tool with large Stokes shift for sensitively detecting carboxylesterase 2 and monitoring its expression in non-alcoholic fatty liver disease

Non-alcoholic fatty liver disease (NAFLD) now affects more than one quarter of the global population and becomes a heavy public health burden. However, the underlying mechanism for the pathogenesis of NAFLD is still not clear. Carboxylesterase 2 (CES2), highly abundant in the liver and intestine, plays an important role in endogenous lipid metabolism and lipolysis. So far, the literatures for the role of CES2 in the development of NAFLD are still limited. In this study, we designed and synthesized a near-infrared fluorescent probe (HP-LZ-CES2) which can be specifically recognized and hydrolyzed by CES2, releasing a benzoate residue and a fluorophore (HP-LZ) with good fluorescence signal. With this probe, CES2 levels can be quantitatively measured in vitro and qualitatively visualized in living cells and mice. The probe has the advantages of large Stokes shift, high detection sensitivity and good selectivity. Further, the CES2 expression levels were visually investigated in both high-fat cells as the in vitro model for NAFLD and high-fat diet fed mouse as the in vivo model for NAFLD. The cell imaging experiments indicated a reduction of fluorescence signal in high-fat hepatic cells. The in vivo experiments showed an obvious reduction of fluorescence in the liver of NAFLD mouse model, which is consistent with the hepatic cell experiments. In contrast, an enhancement of fluorescence was observed in the intestine of NAFLD mouse model. As a result, the NAFLD mouse model can be visually distinguished from the normal chow mouse by vision. Therefore, the proposed probe can be an auxiliary tool for the diagnosis of NAFLD and a visual tool for understanding CES2's role in the development of NAFLD.

Intestinal human carboxylesterase 2 (CES2) expression rescues drug metabolism and most metabolic syndrome phenotypes in global Ces2 cluster knockout mice

Carboxylesterase 2 (CES2) is expressed mainly in liver and intestine, but most abundantly in intestine. It hydrolyzes carboxylester, thioester, and amide bonds in many exogenous and endogenous compounds, including lipids. CES2 therefore not only plays an important role in the metabolism of many (pro-)drugs, toxins and pesticides, directly influencing pharmacology and toxicology in humans, but it is also involved in energy homeostasis, affecting lipid and glucose metabolism. In this study we investigated the pharmacological and physiological functions of CES2. We constructed Ces2 cluster knockout mice lacking all eight Ces2 genes (Ces2-/- strain) as well as humanized hepatic or intestinal CES2 transgenic strains in this Ces2-/- background. We showed that oral availability and tissue disposition of capecitabine were drastically increased in Ces2-/- mice, and tissue-specifically decreased by intestinal and hepatic human CES2 (hCES2) activity. The metabolism of the chemotherapeutic agent vinorelbine was strongly reduced in Ces2-/- mice, but only marginally rescued by hCES2 expression. On the other hand, Ces2-/- mice exhibited fatty liver, adipositis, hypercholesterolemia and diminished glucose tolerance and insulin sensitivity, but without body mass changes. Paradoxically, hepatic hCES2 expression rescued these metabolic phenotypes but increased liver size, adipose tissue mass and overall body weight, suggesting a "healthy" obesity phenotype. In contrast, intestinal hCES2 expression efficiently rescued all phenotypes, and even improved some parameters, including body weight, relative to the wild-type baseline values. Our results suggest that the induction of intestinal hCES2 may combat most, if not all, of the adverse effects of metabolic syndrome. These CES2 mouse models will provide powerful preclinical tools to enhance drug development, increase physiological insights, and explore potential solutions for metabolic syndrome-associated disorders.

Oxymatrine relieves non-alcoholic fatty liver disease by promoting sirtuin 1/adenosine 5'-monophosphate-activated protein kinase pathway and peroxisome proliferator activated receptor alpha-mediated hepatic fatty acid oxidation

Non-alcoholic fatty liver disease (NAFLD) is a liver disease without approved treatment. Oxymatrine (OMT) has protective effects in various liver diseases. We aimed to investigate the roles and mechanisms of OMT in NAFLD. NAFLD models were established using high-fat and high-sucrose diet-fed rats and oleic acid (OA)-stimulated hepatocytes, respectively. Then, OMT was used to treat the NAFLD models, with metformin as a positive control. Liver damage, lipid accumulation and hepatic lipid profile of NAFLD rats were assessed. Peroxisome proliferator activated receptor alpha (PPARα), sirtuin 1 (Sirt1)/adenosine 5'-monophosphate-activated protein kinase (AMPK) pathway- and fatty acid oxidation (acyl-CoA oxidase 1 and carnitine palmitoyltransferase 1A)-associated proteins were measured both in vivo and in vitro. Furthermore, hepatocytes were transfected with si-Sirt1 and oe-PPARα to verify the mechanisms of OMT in NAFLD. NAFLD rats supplemented with OMT displayed reduced liver damage and lipid accumulation. After OMT intervention, the liver lipid profile of NAFLD rats was changed greatly, most of the top differentially expressed lipid metabolites were triglyceride, moreover, diacylglycerol content was decreased in NAFLD rats. OMT activated the Sirt1/AMPK pathway and PPARα, and upregulated acyl-CoA oxidase 1 and carnitine palmitoyltransferase 1A expressions in NAFLD models. In vitro, OMT enhanced viability, and improved lipid accumulation in OA-stimulated hepatocytes. However, the protective functions of OMT in OA-exposed hepatocytes were offset by Sirt1 knockdown, while PPARα overexpression further counteracted the effects of Sirt1 knockdown. OMT could relieve NAFLD by promoting Sirt1/AMPK pathway- and PPARα-mediated hepatic fatty acid oxidation, indicating that OMT is a potential approach for NAFLD treatment.

Association between indoor PM2.5 components and accelerated biological aging in schizophrenia patients: Evidence from multi-omics mechanisms

Indoor fine particulate matter (PM2.5) poses a considerable hazard to the aging process, particularly in vulnerable populations such as schizophrenia patients who frequently spend extended periods in indoor environments. Currently, the evidence on which PM2.5 components contribute to accelerated aging remains unclear. To address these issues, we conducted a prospective, repeated-measurement study on 104 schizophrenia patients. Our findings indicated that exposure to PM2.5 components was significantly associated with accelerated biological aging in schizophrenia patients. Notably, the most prominent effects were observed for thallium (1.303, 95 % CI: 0.481-2.125), chromium (1.029, 95 % CI: 0.303-1.756), lead (1.021, 95 % CI: 0.296-1.746), antimony (0.915, 95 % CI: 0.233-1.597), selenium (0.854, 95 % CI: 0.209-1.499), and manganese (0.833, 95 % CI: 0.186-1.480). Multivariate analysis revealed that PM2.5 components predominantly induced alterations in serum glycerophospholipid metabolites, accelerating the aging process. This intricate connection was closely linked to the gut microbiota, particularly to species such as Dorea and Blautia. Mediation analysis showed that the Blautia-PC (16:0/0:0) pathway mediated the largest proportion (30.69 %) of the effect of manganese exposure on accelerating immune biological aging in schizophrenia patients, as measured using the Klemera-Doubal method. These results underscore the need to address pollution sources that harm health, and provide new evidence for improving regional air quality.

2-Arylhydrazinylidene-3-oxo-3-polyfluoroalkylpropanoic acids as selective and effective carboxylesterase inhibitors with powerful antioxidant potential

A series of 2-arylhydrazinylidene-3-oxo acids (AHOAs) was prepared by dealkylation of alkyl-2-arylhydrazinylidene-3-oxo-3-alkanoates with AlBr3. Using X-Ray, NMR spectroscopy, and quantum mechanical calculations (QM), the existence of AHOAs in a thermodynamically favorable Z-form stabilized by two intramolecular H-bonds was established. All AHOAs had acceptable ADME parameters. The esterase profile study showed that polyfluoroalkyl-AHOAs were effective and selective carboxylesterase (CES) inhibitors, while they were inactive against acetyl- and butyrylcholinesterase. In agreement with molecular docking, the most effective CES inhibitors (IC50 as low as 42 nM) were compounds bearing long polyfluoroalkyl substituents. The acids were also active against hCES1 and hCES2, and CF3-containing acids possessed selectivity against hCES2. Non-fluorinated acids did not inhibit CES, but they exhibited potent antioxidant capability. AHOAs having unsubstituted phenyl or electron-donating groups in the arylhydrazinylidene moiety displayed high primary antioxidant activity in the ABTS, FRAP, and ORAC tests, which did not depend on the substituent in the acyl fragment in the ABTS and ORAC assays. The radical-scavenging mechanism of AHOAs was investigated using QM calculations, showing a preference for cleavage of NH rather than OH bonds. For the lead antioxidants, 4-methoxysubstituted AHOAs, protective effects on erythrocyte membranes in AAPH-induced oxidative stress conditions were shown, including membrane stabilizing activity, inhibition of AAPH-induced lipid peroxidation of erythrocyte membranes, and Fe(II)-chelating ability. Thus, a new class of potent and selective CES inhibitors with powerful antioxidant potential has been developed as promising co-drugs capable of regulating the metabolism of esterified drugs and scavenging reactive radicals that form during Phase I biotransformation.

A methionine-choline-deficient diet induces nonalcoholic steatohepatitis and alters the lipidome, metabolome, and gut microbiome profile in the C57BL/6J mouse

The methionine-choline-deficient (MCD) diet-induced non-alcoholic steatohepatitis (NASH) in mice is a well-established model. Our study aims to elucidate the factors influencing liver pathology in the MCD mouse model by examining physiological, biochemical, and molecular changes using histology, molecular techniques, and OMICS approaches (lipidomics, metabolomics, and metagenomics). Male C57BL/6J mice were fed a standard chow diet, a methionine-choline-sufficient (MCS) diet, or an MCD diet for 10 weeks. The MCD diet resulted in reduced body weight and fat mass, along with decreased plasma triglyceride, cholesterol, glucose, and insulin levels. However, it notably induced steatosis, inflammation, and alterations in gene expression associated with lipogenesis, inflammation, fibrosis, and the synthesis of apolipoproteins, sphingolipids, ceramides, and carboxylesterases. Lipid analysis revealed significant changes in plasma and tissues: most ceramide non-hydroxy-sphingosine lipids significantly decreased in the liver and plasma but increased in the adipose tissue of MCD diet-fed animals. Oxidized glycerophospholipids mostly increased in the liver but decreased in the adipose tissue of the MCD diet-fed group. The gut microbiome of the MCD diet-fed group showed an increase in Firmicutes and a decrease in Bacteroidetes and Actinobacteria. Metabolomic profiling demonstrated that the MCD diet significantly altered amino acid biosynthesis, metabolism, and nucleic acid metabolism pathways in plasma, liver, fecal, and cecal samples. LC-MS data indicated higher total plasma bile acid intensity and reduced fecal glycohyodeoxycholic acid intensity in the MCD diet group. This study demonstrates that although the MCD diet induces hepatic steatosis, the mechanisms underlying NASH in this model differ from those in human NASH pathology.

Transcriptome and Metabolome Based Mechanisms Revealing the Accumulation and Transformation of Sugars and Fats in Pinus armandii Seed Kernels during the Harvesting Period

Pinus armandii seed kernel is a nutrient-rich and widely consumed nut whose yield and quality are affected by, among other things, harvesting time and climatic conditions, which reduce economic benefits. To investigate the optimal harvesting period of P. armandii seed kernels, this study determined the nutrient composition and seed kernel morphology and analyzed the gene expression and metabolic differences of P. armandii seed kernels during the harvesting period by transcriptomics and metabolomics. The results revealed that during the maturation of P. armandii seed kernels, there was a significant increase in the width, thickness, and weight of the seed kernels, as well as a significant accumulation of sucrose, soluble sugars, proteins, starch, flavonoids, and polyphenols and a significant decrease in lipid content. In addition, transcriptomic and metabolomic analyses of P. armandii seed kernels during the harvesting period screened and identified 103 differential metabolites (DEMs) and 8899 differential genes (DEGs). Analysis of these DEMs and DEGs revealed that P. armandii seed kernel harvesting exhibited gene-metabolite differences in sugar- and lipid-related pathways. Among them, starch and sucrose metabolism, glycolysis, and gluconeogenesis were associated with the synthesis and catabolism of sugars, whereas fatty acid degradation, glyoxylate and dicarboxylic acid metabolism, and glycerophospholipid metabolism were associated with the synthesis and catabolism of lipids. Therefore, the present study hypothesized that these differences in genes and metabolites exhibited during the harvesting period of P. armandii seed kernels might be related to the accumulation and transformation of sugars and lipids. This study may provide a theoretical basis for determining the optimal harvesting time of P. armandii seed kernels, changes in the molecular mechanisms of nutrient accumulation, and quality directed breeding.

Liver matrin-3 protects mice against hepatic steatosis and stress response via constitutive androstane receptor

OBJECTIVE

The prevalence of metabolic dysfunction-associated steatotic liver disease (MASLD) continues to rise with the increasing obesity epidemic. Rezdiffra as an activator of a thyroid hormone receptor-beta is the only Food and Drug Administration approved therapy. As such, there is a critical need to improve our understanding of gene expression regulation and signaling transduction in MASLD to develop new therapies. Matrin-3 is a DNA- and RNA-binding protein involved in the pathogenesis of human diseases. Here we examined its previously uncharacterized role in limiting hepatic steatosis and stress response via the constitutive androstane receptor (CAR).

METHODS

Matrin-3 floxed and liver-specific knockout mice were fed either a chow diet or 60 kcal% high-fat diet (HFD) for up to 16 weeks. The mice were euthanized for different analysis including liver histology, lipid levels, and gene expression. Bulk RNA-seq, bulk ATAC-seq, and single-nucleus Multiome were used to examine changes of transcriptome and chromatin accessibility in the liver. Integrative bioinformatics analysis of our data and publicly available datasets and different biochemical assays were performed to identify underlying the molecular mechanisms mediating matrin-3's effects. Liver-tropic adeno-associated virus was used to restore the expression of CAR for lipid, acute phase genes, and histological analysis.

RESULTS

Matrin-3 expression is induced in the steatotic livers of mice. Liver-specific matrin-3 deletion exacerbated HFD-induced steatosis, acute phase response, and inflammation in the liver of female mice. The transcriptome and chromatin accessibility were re-programmed in the liver of these mice with signatures indicating that CAR signaling is dysregulated. Mechanistically, matrin-3 interacts with CAR mRNA, and matrin-3 deficiency promotes CAR mRNA degradation. Consequently, matrin-3 deletion impaired CAR signaling by reducing CAR expression. Matrin-3 levels positively correlate with CAR expression in human livers. Ces2a and Il1r1 were identified as new target genes of CAR. Interestingly, we found that CAR discords with the expression of its target genes including Cyp2b10 and Ces2a in response to HFD, indicating CAR signaling is dysregulated by HFD despite increased CAR expression. Dysregulated CAR signaling upon matrin-3 deficiency reduced Ces2a and de-repressed Il1r1 expression. CAR restoration partially abrogated the dysregulated gene expression, exacerbated hepatic steatosis, acute phase response, and inflammation in liver-specific matrin-3 knockout mice fed a HFD.

CONCLUSIONS

Our findings demonstrate that matrin-3 is a key upstream regulator maintaining CAR signaling upon metabolic stress, and the matrin-3-CAR axis limits hepatic steatosis and stress response signaling that may give insights for therapeutic intervention.

From Hypothalamic Obesity to Metabolic Dysfunction-Associated Steatotic Liver Disease: Physiology Meets the Clinics via Metabolomics

Metabolic health is tightly regulated by neuro-hormonal control, and systemic metabolic dysfunction may arise from altered function of the hypothalamic-anterior pituitary axis (HAPA). Ancient experimental observations of hypothalamic obesity (HO) and liver cirrhosis occurring among animals subjected to hypothalamic injury can now be explained using the more recent concepts of lipotoxicity and metabolic dysfunction-associated steatotic liver disease (MASLD). Lipotoxicity, the range of abnormalities resulting from the harmful effects of fatty acids accumulated in organs outside of adipose tissue, is the common pathogenic factor underlying closely related conditions like hypothalamic syndrome, HO, and MASLD. The hormonal deficits and the array of metabolic and metabolomic disturbances that occur in cases of HO are discussed, along with the cellular and molecular mechanisms that lead, within the MASLD spectrum, from uncomplicated steatotic liver disease to steatohepatitis and cirrhosis. Emphasis is placed on knowledge gaps and how they can be addressed through novel studies. Future investigations should adopt precision medicine approaches by precisely defining the hormonal imbalances and metabolic dysfunctions involved in each individual patient with HO, thus paving the way for tailored management of MASLD that develops in the context of altered HAPA.

In Situ Visualizing Carboxylesterase Activity in Type 2 Diabetes Mellitus Using an Activatable Endoplasmic Reticulum Targetable Proximity Labeling Far-Red Fluorescent Probe

Carboxylesterase (CE), an enzyme widely present in organisms, is involved in various physiological and pathological processes. Changes in the levels of CEs in the liver may predict the presence of type 2 diabetes mellitus (T2DM). Here, a novel dicyanoisophorone (DCI)-based proximity-labeled far-red fluorescent probe DCI2F-Ac with endoplasmic reticulum targeting was proposed for real-time monitoring and imaging of the CEs activity. DCI2F-Ac featured very low cytotoxicity and biotoxicity and was highly selective and sensitive for CEs. Compared with traditional CEs probes, DCI2F-Ac was covalently anchored directly to CEs, thus effectively reducing the loss of in situ fluorescent signals due to diffusion. Through the "on-off" fluorescence signal readout, DCI2F-Ac was able to distinguish cell lines and screen for CEs inhibitors. In terms of endoplasmic reticulum (ER) stress, it was found that thapsigargin (Tg) induced upregulation of CEs levels but not tunicamycin (Tm), which was related to the calcium homeostasis of the ER. DCI2F-Ac could efficiently detect downregulated CEs in the livers of T2DM, and the therapeutic efficacy of metformin, acarbose, and a combination of these two drugs was assessed by tracking the fluctuation of CEs levels. The results showed that combining metformin and acarbose could restore CEs levels to near-normal levels with the best antidiabetic effect. Thus, the DCI2F-Ac probe provides a great opportunity to explore the untapped potential of CEs in liver metabolic disorders and drug efficacy assessment.

Role of carboxylesterase and arylacetamide deacetylase in drug metabolism, physiology, and pathology

Carboxylesterases (CES1 and CES2) and arylacetamide deacetylase (AADAC), which are expressed primarily in the liver and/or gastrointestinal tract, hydrolyze drugs containing ester and amide bonds in their chemical structure. These enzymes often catalyze the conversion of prodrugs, including the COVID-19 drugs remdesivir and molnupiravir, to their pharmacologically active forms. Information on the substrate specificity and inhibitory properties of these enzymes, which would be useful for drug development and toxicity avoidance, has accumulated. Recently,in vitroandin vivostudies have shown that these enzymes are involved not only in drug hydrolysis but also in lipid metabolism. CES1 and CES2 are capable of hydrolyzing triacylglycerol, and the deletion of their orthologous genes in mice has been associated with impaired lipid metabolism and hepatic steatosis. Adeno-associated virus-mediated human CES overexpression decreases hepatic triacylglycerol levels and increases fatty acid oxidation in mice. It has also been shown that overexpression of CES enzymes or AADAC in cultured cells suppresses the intracellular accumulation of triacylglycerol. Recent reports indicate that AADAC can be up- or downregulated in tumors of various organs, and its varied expression is associated with poor prognosis in patients with cancer. Thus, CES and AADAC not only determine drug efficacy and toxicity but are also involved in pathophysiology. This review summarizes recent findings on the roles of CES and AADAC in drug metabolism, physiology, and pathology.

Finasteride delays atherosclerosis progression in mice and is associated with a reduction in plasma cholesterol in men

Finasteride is commonly prescribed to treat benign prostate hyperplasia and male-pattern baldness in cis men and, more recently, trans individuals. However, the effect of finasteride on cardiovascular disease remains elusive. We evaluated the role of finasteride on atherosclerosis using low-density lipoprotein (LDL) receptor-deficient (Ldlr-/-) mice. Next, we examined the relevance to humans by analyzing the data deposited between 2009 and 2016 in the National Health and Nutrition Examination Survey. We show that finasteride reduces total plasma cholesterol and delays the development of atherosclerosis in Ldlr-/- mice. Finasteride reduced monocytosis, monocyte recruitment to the lesion, macrophage lesion content, and necrotic core area, the latter of which is an indicator of plaque vulnerability in humans. RNA sequencing analysis revealed a downregulation of inflammatory pathways and an upregulation of bile acid metabolism, oxidative phosphorylation, and cholesterol pathways in the liver of mice taking finasteride. Men reporting the use of finasteride showed lower plasma levels of cholesterol and LDL-cholesterol than those not taking the drug. Our data unveil finasteride as a potential treatment to delay cardiovascular disease in people by improving the plasma lipid profile.

Isoquercitrin attenuates the progression of non-alcoholic steatohepatitis in mice by modulating galectin-3-mediated insulin resistance and lipid metabolism

BACKGROUND

Non-alcoholic steatohepatitis (NASH) is a global health problem with no effective treatment. Isoquercitrin (IQ) alters hepatic lipid metabolism and inhibits adipocyte differentiation. The underlying regulatory mechanisms of IQ in regulating insulin resistance (IR) and lipid metabolism remain unclear.

PURPOSE

This study was aimed at investigating the effects of IQ on NASH and deciphering whether the underlying mechanisms are via modulation of galectin-3 mediated IR and lipid metabolism.

METHODS

IR-HepG2 cell lines were used to demonstrate the ability of IQ to modulate galectin-3-mediated glucose disposal and lipid metabolism. A 20-week high-fat diet (HFD)-induced NASH model was established in C57BL/6J mice, and the protective effect of IQ on lipid disposal in the liver was verified. Further, the mRNA and protein levels of glucose and lipid metabolism were investigated, and lysophosphatidylcholine (LPC) and acylcarnitine (AC) profiling were performed to characterize the changes in endogenous substances associated with mitochondrial function and lipid metabolism in serum and cells. Furthermore, the pharmacokinetic features of IQ were explored in a rat model of NASH.

RESULTS

IQ restored liver function and ameliorated inflammation and lipid accumulationin NASH model mice. Notably, significant regulation of the proteins included fatty acid-generating and transporting, cholesterol metabolism enzymes, nuclear transcription factors, mitochondrial metabolism, and IR-related enzymes was noted to be responsible for the therapeutic mechanisms of IQ against experimental NASH. Serum lipid metabolism-related metabolomic assay confirmed that LPC and AC biosynthesis mostly accounted for the therapeutic effect of IQ in mice with NASH and that IQ maintained the homeostasis of LPC and AC levels.

CONCLUSION

This is the first study showing that IQ protects against of NASH by modulating galectin-3-mediated IR and lipid metabolism. The mechanisms responsible for liver protection and improved lipid metabolic disorder by IQ may be related to the suppression of IR and regulation of mitochondrial function and lipid metabolism. Galectin-3 down-regulation represents a potentially novel approach for the treatment and prevention of NASH.

Metabolic and Hepatic Effects of Empagliflozin on Nonalcoholic Fatty Liver Mice

Purpose

Among chronic liver diseases, non-alcoholic fatty liver disease (NAFLD) is one of the commonest. Although empagliflozin has several therapeutic uses in treating cardiovascular and renal disorders, its impacts and mechanisms on NAFLD are poorly understood. This research aimed to examine the metabolic regulatory mechanism through which empagliflozin protects against NAFLD.

Methods

Equal grouping of twenty-seven male C57BL/6J mice into those fed a normal diet (NCD), those fed a high-fat diet (HFD), and those fed an HFD with empagliflozin (Empa) was approached. HE, oil red O staining, and Masson staining were utilized for evaluating the pathological damage to the liver and the mice's liver and body weights. Lipids, blood glucose, and inflammation index were compared across the three groups. Liquid chromatography/mass spectrometry (LC-MS) has been employed for identifying liver metabolomics.

Results

The findings suggested that empagliflozin mitigated the inflammatory and oxidative stress response associated with the buildup of lipids caused by HFD. Differentially expressed metabolites (DEMs) were identified by metabonomics analysis as present in both the HFD/NCD and Empa/HFD groups. These DEMs were primarily found in lipids and organic acids like lysophosphatidylcholine (lysoPC), lecithin (PC), triglyceride (TG), palmitic acid, and L-isoleucine. Among the enriched pathways that were shown to be important were those involved in the metabolism of histidine, arachidonic acid, the control of lipolysis in adipocytes, and insulin resistance. There was a strong correlation between inflammation and oxidative stress in most of the metabolites. The inflammation and oxidative stress unbalance were ameliorated by empagliflozin.

Conclusion

NAFLD mice model showed considerable improvement in metabolic abnormalities and liver protection after treatment with empagliflozin. The process may include the overexpression of L-isoleucine and the downregulation of lysoPC, PC, TG, and palmitic acid to reduce liver harm caused by lipotoxicity.