Dysfunction of estrogen-related receptor alpha-dependent hepatic VLDL secretion contributes to sex disparity in NAFLD/NASH development

miR-125b-5p regulates FFA-induced hepatic steatosis in L02 cells by targeting estrogen-related receptor alpha

BACKGROUND & AIMS

NAFLD is a global and complex liver disease caused by multiple factors. Intrahepatocellular steatosis is the primary prerequisite for the occurrence and development of NAFLD. It has been shown that miR-125b-5p is highly correlated with NAFLD, and ESRRA is a factor that regulates lipid metabolism. The purpose of our study is to investigate whether miR-125b-5p regulates FFA-induced steatosis in L02 cells by targeting ESRRA.

APPROACHES AND RESULTS

Estrogen-related receptor alpha (ESRRA) was identified as a direct target of miR-125b-5p through database prediction and a dual-luciferase reporter gene assay. L02 cells were induced with free fatty acids (OA:PA, 2:1) at concentrations of 0.3 mM, 0.6 mM, 0.9 mM, 1.2 mM and 1.5 mM for 24 h, 48 h and 72 h, respectively. The degree of hepatocyte steatosis and triglyceride content were separately manifested by oil red O staining and colorimetric method. Cell viability per group was detected by CCK-8 assay. Eventually, 0.9 mM and 24 h were screened out as the optimal concentration and time for establishing the in-vitro model of hepatic steatosis. Followingly, miR-125b-5p and ESRRA were knocked down by transient transfection. We monitored the expressions of lipid metabolism factors SREBP-1c, ACC1 and FAS and determine triglyceride content within the cells per group. The data showed that knockdown of ESRRA led to down-regulation of the expressions of SREBP-1, ACC1, FAS and triglyceride content. Meanwhile, knockdown of ESRRA and miR-125b-5p resulted that the expressions of ESRRA, SREBP-1, ACC1, FAS and triglyceride content rebounded.

CONCLUSIONS

MiR-125b-5p down-regulates the expressions of lipid metabolism-related factors by negatively regulating ESRRA, thereby improving hepatic steatosis.

Multiomics Reveal the Effects and Regulatory Mechanism of Naringin on Metabolic Dysfunction-Associated Fatty Liver Disease of Laying Hens

This study aimed to utilize aged laying hens as a model to investigate the effects of naringin on the occurrence and progression of metabolic dysfunction-associated fatty liver disease (MAFLD), along with its underlying regulatory mechanisms. A total of 288 aged laying hens, 50-week-old, were divided into four groups: a normal diet (ND) group, and three naringin groups receiving 200 mg/kg (N1), 400 mg/kg (N2), and 600 mg/kg (N3). The experiment lasted for 10 weeks, after which serum, liver, and cecal contents were collected from the hens. Results indicated that dietary naringin supplementation reduced hepatic lipid deposition, lowered blood lipid levels, improved antioxidant capacity, and promoted estradiol secretion. Additionally, 16S rDNA analysis revealed that naringin enhanced microbial diversity in the cecum and regulated the abundance of gut microbes associated with fatty liver. Untargeted metabolomics of blood demonstrated that naringin decreased the concentration of glycerophospholipid and sterol lipid metabolites while increasing levels of pantothenic acids and amino acid metabolites. Furthermore, liver transcriptome analysis indicated that naringin interfered with fatty acid synthesis and transport processes while enhancing fatty acid oxidation. Dietary naringin supplementation can mitigate the occurrence of MAFLD by regulating the gut-liver axis and estrogen signaling, particularly in postmenopausal women.

SGLT2 inhibitor empagliflozin ameliorates tubulointerstitial fibrosis in DKD by downregulating renal tubular PKM2

BACKGROUND AND OBJECTIVE

Sodium-glucose cotransporter 2 (SGLT2) inhibitors have been shown to prevent the progression of diabetic kidney disease (DKD). However, their impact on renal fibrosis remains largely uninvestigated. This study aimed to explore the effect of SGLT2 inhibitor empagliflozin on renal fibrosis in DKD patients and DKD models, and the molecular mechanisms involved.

METHODS

Kidney samples of DKD patients and DKD models were used in this study. DKD mouse models included STZ-treated CD-1 mice and HFD-fed C57BL/6 mice were all treated with empagliflozin for 6 to 12 weeks. Kidney pathological changes were analysed and fibrotic factors were detected. HK-2 cells were treated with normal glucose (NG), high glucose (HG), or HG with empagliflozin. RNA sequencing was employed to identify the differentially expressed genes. Epithelial-mesenchymal transition (EMT) markers were detected. Binding of transcription factor and target gene was determined using a dual-luciferase reporter assay.

RESULTS

Empagliflozin significantly ameliorated kidney fibrosis in DKD patients and DKD models. This was evidenced by tubulointerstitial fibrosis reduction observed through PAS and Masson staining, along with fibrotic factors downregulation. RNA sequencing and the subsequent in vitro and in vivo validation identified PKM2 as the most significantly upregulated glycolytic enzyme in DKD patients and models. Empagliflozin downregulated PKM2 and alleviated EMT and renal fibrosis. Importantly, empagliflozin improves fibrosis by downregulating PKM2. The downregulation of PKM2 by empagliflozin was achieved by inhibiting the binding of estrogen-related receptor α at the promoter.

CONCLUSIONS

Empagliflozin ameliorates kidney fibrosis via downregulating PKM2 in DKD.

The association of advanced lung cancer inflammation index with non-alcoholic fatty liver disease in NHANES 2017-2020

Background

The advanced lung cancer inflammation index (ALI) is a composite index that combines inflammation and nutritional status, and non-alcoholic fatty liver disease (NAFLD) is associated with inflammation, nutritional status, and obesity. This study aimed to investigate the possible relationship between ALI and NAFLD.

Methods

We extracted cohort datasets from the 2017-2020 National Health and Nutrition Examination Survey (NHANES) for the study. Weighted analyses and multivariate linear regression models were applied to assess the association between ALI and NAFLD. Fitted curves and threshold effects analyses were used to characterize nonlinear relationships.

Results

A total of 6,595 adults aged 18-80 years were included in this study. In multivariate linear regression analysis, there was a significant positive association between ALI and NAFLD [OR: 1.02, 95% CI (1.01, 1.02)]. In subgroup analyses, this positive association was maintained in females [OR: 1.02, 95% CI (1.01, 1.02)] and not in males. In addition, we found that the association between ALI and NAFLD was nonlinear, with an L-shaped relationship and an inflection point of 32.47. ALI showed a U-shaped association with NAFLD in the male population, with an inflection point of 40.65, and an L-shaped association in the female population, with an inflection point of 30.61.

Conclusion

Our study suggests that there is a significant positive association between high ALI levels and NAFLD prevalence in the US adult population. However, more clinical cohort studies are needed to confirm this finding.

MASLD: Prevalence, Mechanisms, and Sex-Based Therapies in Postmenopausal Women

Metabolic dysfunction-associated steatotic liver disease (MASLD) is the most common chronic liver disease influenced by genetic, lifestyle, and environmental factors. While MASLD is more prevalent in men, women are at increased risk after menopause, highlighting the critical pathogenetic role of sex hormones. The complex interplay between estrogen deficiency, visceral fat accumulation, metabolic syndrome (MetS), and inflammation accelerates disease progression, increases cardiovascular (CV) risk, and triggers a cycle of worsening adiposity, metabolic dysfunction, and psychological problems, including eating disorders. Weight loss in postmenopausal women can significantly improve both metabolic and psychological outcomes, helping to prevent MASLD and related conditions. This review examines the prevalence of MASLD, its comorbidities (type 2 diabetes T2D, CV, mental disorders), pathogenetic mechanisms, and pharmacological treatment with GLP-1 receptor agonists (GLP1-RAs), with a focus on postmenopausal women. Given the use of GLP1-RAs in the treatment of obesity and T2D in MASLD patients, and the increase in MetS and MASLD after menopause, this review analyzes the potential of a stable GLP-1-estrogen conjugate as a therapeutic approach in this subgroup. By combining the synergistic effects of both hormones, this dual agonist has been shown to increase food intake and food reward suppression, resulting in greater weight loss and improved insulin sensitivity, glucose, and lipid metabolism. Therefore, we hypothesize that this pharmacotherapy may provide more targeted therapeutic benefits than either hormone alone by protecting the liver, β-cells, and overall metabolic health. As these effects are only supported by preclinical data, this review highlights the critical need for future research to evaluate and confirm the mechanisms and efficacy in clinical settings, particularly in postmenopausal women.

GOLM1 promotes cholesterol gallstone formation via ABCG5-mediated cholesterol efflux in metabolic dysfunction-associated steatohepatitis livers

BACKGROUND/AIMS

Metabolic dysfunction-associated steatohepatitis (MASH) is a significant risk factor for gallstone formation, but mechanisms underlying MASH-related gallstone formation remain unclear. Golgi membrane protein 1 (GOLM1) participates in hepatic cholesterol metabolism and is upregulated in MASH. Here, we aimed to explore the role of GOLM1 in MASH-related gallstone formation.

METHODS

The UK Biobank cohort was used for etiological analysis. GOLM1 knockout (GOLM1-/-) and wild-type (WT) mice were fed with a high-fat diet (HFD). Livers were excised for histology and immunohistochemistry analysis. Gallbladders were collected to calculate incidence of cholesterol gallstones (CGSs). Biles were collected for biliary lipid analysis. HepG2 cells were used to explore underlying mechanisms. Human liver samples were used for clinical validation.

RESULTS

MASH patients had a greater risk of cholelithiasis. All HFD-fed mice developed MASH, and the incidence of gallstones was 16.7% and 75.0% in GOLM1-/- and WT mice, respectively. GOLM1-/- decreased biliary cholesterol concentration and output. In vivo and in vitro assays confirmed that GOLM1 facilitated cholesterol efflux through upregulating ATP binding cassette transporter subfamily G member 5 (ABCG5). Mechanistically, GOLM1 translocated into nucleus to promote osteopontin (OPN) transcription, thus stimulating ABCG5-mediated cholesterol efflux. Moreover, GOLM1 was upregulated by interleukin-1β (IL-1β) in a dose-dependent manner. Finally, we confirmed that IL-1β, GOLM1, OPN, and ABCG5 were enhanced in livers of MASH patients with CGSs.

CONCLUSION

In MASH livers, upregulation of GOLM1 by IL-1β increases ABCG5-mediated cholesterol efflux in an OPN-dependent manner, promoting CGS formation. GOLM1 has the potential to be a molecular hub interconnecting MASH and CGSs.

Influence of Sex in the Development of Liver Diseases

The liver is a sexually dimorphic organ. Sex differences in prevalence, progression, prognosis, and treatment prevail in most liver diseases, and the mechanism of how liver diseases act differently among male versus female patients has not been fully elucidated. Biological sex differences in normal physiology and disease arise principally from sex hormones and/or sex chromosomes. Sex hormones contribute to the development and progression of most liver diseases, with estrogen- and androgen-mediated signaling pathways mechanistically involved. In addition, genetic factors in sex chromosomes have recently been found to contribute to the sex disparity of many liver diseases, which might explain, to some extent, the difference in gene expression pattern, immune response, and xenobiotic metabolism between men and women. Although increasing evidence suggests that sex is one of the most important modulators of disease prevalence and outcomes, at present, basic and clinical studies have long been sex unbalanced, with female subjects underestimated. As such, this review focuses on sex disparities of liver diseases and summarizes the current understanding of sex-specific mechanisms, including sex hormones, sex chromosomes, etc. We anticipate that understanding sex-specific pathogenesis will aid in promoting personalized therapies for liver disease among male versus female patients.

PPARα-ERRα crosstalk mitigates metabolic dysfunction-associated steatotic liver disease progression

BACKGROUND AND AIMS

Metabolic dysfunction-associated steatotic liver disease (MASLD), the most prevalent liver disease worldwide, continues to rise. More effective therapeutic strategies are urgently needed. We investigated how targeting two key nuclear receptors involved in hepatic energy metabolism, peroxisome proliferator-activated receptor alpha (PPARα) and estrogen-related receptor alpha (ERRα), ameliorates MASLD.

METHODS

The PPARα agonist pemafibrate and/or ERRα inverse agonist C29 were administered in a short- and long-term Western diet plus fructose model, and a diabetic-background streptozotocin-Western diet model (STZ-WD). Liver and adipose tissue morphology, histological samples, serum metabolites, RNA and protein levels were analysed and scanning electron microscopy was performed. In addition, we performed cell-based assays and immunohistochemistry and immunofluorescence stainings with light and super-resolution confocal microscopy of healthy, MASLD and MASH human livers.

RESULTS

The ligand combinations' efficacy was highlighted by reduced liver steatosis across all mouse models, alongside improvements in body weight, inflammation, and fibrosis in both long-term models. Additionally, tumour formation was prevented in the STZ-WD mice model. Cell-based assays demonstrated that ERRα inhibits PPARα's activity, explaining why ERRα blockage improves inflammatory and lipid metabolism gene profiles and enhances lipid-lowering effects. Complementary RNA sequencing and shotgun proteomics, combined with enrichment analysis, jointly identified downregulated serum amyloid A1/A2 as essential components underlying the combination treatment's effectiveness. MASLD/MASH patient livers showed reduced PPARα and increased ERRα levels supporting disrupted NR crosstalk in the hepatocyte nucleus.

CONCLUSION

Our study supports that dual nuclear receptor targeting, which simultaneously increases PPARα and diminishes ERRα activity, may represent a viable novel strategy against MASLD.

IMPACT AND IMPLICATIONS

Our research introduces a novel therapeutic strategy against MASLD by simultaneously increasing PPARα activity while diminishing ERRα activity. With PPARα agonists already tested in phase III clinical trials, ERRα ligands/modulators need further (clinical) development to make our findings applicable to both MASLD patients and physicians.

Curcumin Supplementation as a Preventive Strategy Against Tamoxifen-Induced Nonalcoholic Fatty Liver Disease in ER+ Breast Cancer Patients: A Triple-Blind Randomized Placebo-Controlled Trial

Tamoxifen, a common treatment for estrogen receptor (ER)‑positive breast cancer, is associated with an increased risk of developing nonalcoholic fatty liver disease (NAFLD). Curcumin, a compound in turmeric, has shown potential in mitigating liver disease progression. This study aims to evaluate the efficacy and safety of curcumin in preventing NAFLD in breast cancer patients initiating tamoxifen therapy.In this 6‑month triple‑blind, randomized placebo‑controlled trial, 44 ER+ breast cancer patients scheduled to receive tamoxifen were assigned to receive either curcumin (500 mg daily) or a placebo. NAFLD grade was assessed via ultrasound at baseline and after 6 months. Laboratory values and demographic data were collected, and adverse effects were monitored. Statistical analyses was performed using SPSS version 16.Data of a total of 44 participants (22 participants in each group, mean age: 47.1 ± 6.0 years) were analyses. There were no significant differences between the placebo and curcumin groups regarding the demographic and baseline laboratory values. At study completion, significantly fewer patients in the curcumin group showed an increased NAFLD grade compared to the placebo group (13.6% vs. 54.5%; p = 0.03). Additionally, the prevalence of NAFLD grade ≥ 2 was lower in the curcumin group (13.6% vs. 40.9%; p = 0.04). No adverse effects related to curcumin were reported. Curcumin supplementation demonstrated a protective effect against tamoxifen‑induced NAFLD in ER+ breast cancer patients, suggesting its potential as a prophylactic adjunct to tamoxifen therapy. Larger multi‑centric trials are warranted to confirm these findings.

Non-canonical hepatic androgen receptor mediates glucagon sensitivity in female mice through the PGC1α/ERRα/mitochondria axis

Glucagon has recently been found to modulate liver fat content, in addition to its role in regulating gluconeogenesis. However, the precise mechanisms by which glucagon signaling synchronizes glucose and lipid metabolism in the liver remain poorly understood. By employing chemical and genetic approaches, we demonstrate that inhibiting the androgen receptor (AR) impairs the ability of glucagon to stimulate gluconeogenesis and lipid catabolism in primary hepatocytes and female mice. Notably, AR expression in the liver of female mice is up to three times higher than that in their male littermates, accounting for the more pronounced response to glucagon in females. Mechanistically, hepatic AR promotes energy metabolism and enhances lipid breakdown for liver glucose production in response to glucagon treatment through the peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC1α)/estrogen-related receptor alpha (ERRα)-mitochondria axis. Overall, our findings highlight the crucial role of hepatic AR in mediating glucagon signaling and the sexual dimorphism in hepatic glucagon sensitivity.

Disparities in Metabolic Dysfunction-Associated Steatotic Liver Disease Prevalence, Diagnosis, Treatment, and Outcomes: A Narrative Review

BACKGROUND

Metabolic dysfunction-associated steatotic liver disease (MASLD), formerly known as non-alcoholic fatty liver disease (NAFLD), is a leading cause of morbidity and mortality, and health disparities have been shown to influence disease burden.

AIM

In this review, we aim to characterize disparities in prevalence, diagnosis, treatment, and outcomes of MASLD, and to make recommendations for next steps to minimize these disparities.

METHODS

Literature search on PubMed and Scopus databases was conducted to identify relevant articles published before September 2, 2024.

RESULTS

Relative to women and White populations, MASLD is more common in men and Hispanic populations and less common in Black populations. It is also more prevalent among those with lower SES. Noninvasive clinical scores may perform differently across groups, and screening practices vary both for initial disease and for progression to metabolic dysfunctionassociated steatohepatitis (MASH), formerly called non-alcoholic steatohepatitis (NASH). Women and Black and Hispanic patients suffer worse outcomes including rates of progression to MASH and mortality.

CONCLUSIONS

Health disparities related to race, ethnicity, gender, and socioeconomic factors impact multiple stages of care for patients with MASLD.

ASGR1 Deficiency Inhibits Atherosclerosis in Western Diet-Fed ApoE-/- Mice by Regulating Lipoprotein Metabolism and Promoting Cholesterol Efflux

BACKGROUND

Atherosclerosis is the most common cause of cardiovascular diseases. Clinical studies indicate that loss-of-function ASGR1 (asialoglycoprotein receptor 1) is significantly associated with lower plasma cholesterol levels and reduces cardiovascular disease risk. However, the effect of ASGR1 on atherosclerosis remains incompletely understood; whether inhibition of ASGR1 causes liver injury remains controversial. Here, we comprehensively investigated the effects and the underlying molecular mechanisms of ASGR1 deficiency and overexpression on atherosclerosis and liver injury in mice.

METHODS

We engineered Asgr1 knockout mice (Asgr1-/-), Asgr1 and ApoE double-knockout mice (Asgr1-/-ApoE-/-), and ASGR1-overexpressing mice on an ApoE-/- background and then fed them different diets to assess the role of ASGR1 in atherosclerosis and liver injury.

RESULTS

After being fed a Western diet for 12 weeks, Asgr1-/-ApoE-/- mice exhibited significantly decreased atherosclerotic lesion areas in the aorta and aortic root sections, reduced plasma VLDL (very-low-density lipoprotein) cholesterol and LDL (low-density lipoprotein) cholesterol levels, decreased VLDL production, and increased fecal cholesterol contents. Conversely, ASGR1 overexpression in ApoE-/- mice increased atherosclerotic lesions in the aorta and aortic root sections, augmented plasma VLDL cholesterol and LDL cholesterol levels and VLDL production, and decreased fecal cholesterol contents. Mechanistically, ASGR1 deficiency reduced VLDL production by inhibiting the expression of MTTP (microsomal triglyceride transfer protein) and ANGPTL3 (angiopoietin-like protein 3)/ANGPTL8 (angiopoietin-like protein 8) but increasing LPL (lipoprotein lipase) activity, increased LDL uptake by increasing LDLR (LDL receptor) expression, and promoted cholesterol efflux through increasing expression of LXRα (liver X receptor-α), ABCA1 (ATP-binding cassette subfamily A member 1), ABCG5 (ATP-binding cassette subfamily G member 5), and CYP7A1 (cytochrome P450 family 7 subfamily A member 1). These underlying alterations were confirmed in ASGR1-overexpressing ApoE-/- mice. In addition, ASGR1 deficiency exacerbates liver injury in Western diet-induced Asgr1-/-ApoE-/- mice and high-fat diet-induced but not normal laboratory diet-induced and high-fat and high-cholesterol diet-induced Asgr1-/- mice, while its overexpression mitigates liver injury in Western diet-induced ASGR1-overexpressing ApoE-/- mice.

CONCLUSIONS

Inhibition of ASGR1 inhibits atherosclerosis in Western diet-fed ApoE-/- mice, suggesting that inhibiting ASGR1 may serve as a novel therapeutic strategy to treat atherosclerosis and cardiovascular diseases.

Andrographolide prevents renal fibrosis via decelerating lipotoxicity-mediated premature senescence of tubular epithelial cells

Excessive lipid accumulation often occurs in the early stage of chronic kidney disease (CKD) which is prone to induce oxidative stress and mitochondrial damage, promoting the progression of kidney fibrosis. Andrographolide (AP), a multifunctional natural terpenoids derived from Andrographis paniculate, has been suggested to play beneficial roles in metabolic disorders-associated disease. Here, we reported that AP effectively counteracts tubule injury and interstitial fibrosis in mice fed with a long-term high-fat diet (HFD). AP treatment decreased HFD-induced lipid accumulation in kidney parenchyma and attenuated lipotoxicity-mediated oxidative stress and mitochondrial dysfunction, resulting in a marked decrease in tubular cell senescence. Importantly, AP inhibited senescence-associated secretory phenotype (SASP) secretion by senescent tubular cells, and in turn suppressed proliferation and activation of fibroblasts in a paracrine effect. Furthermore, we revealed that AP functions as an AMP-activated protein kinase (AMPK) activator to ameliorate renal lipid accumulation through coordinately modulating AMP-activated protein kinase AMPK target genes. By stimulation of AMPK activity, AP protects injured kidney against tubular cell senescence and fibroblast activation. These results suggest the potential therapeutic application of AP in the prevention and treatment of CKD, highlighting the promising drug strategy of targeting the lipotoxicity-mediated premature senescence in tubular cells.

Estrogen: the forgotten player in metaflammation

Metaflammation is low-grade inflammation triggered by chronic metabolic imbalance and caused by dysregulated metabolites in metabolic inflammatory syndrome (MIS), which includes four diseases: obesity, type 2 diabetes mellitus (T2DM), atherosclerosis (AS), and nonalcoholic fatty liver diseases (NAFLD, recently proposed to be replaced by metabolic dysfunction-associated steatotic liver disease, MASLD). These diseases exhibit apparent sex dimorphism as regards MIS. Estrogen not only plays a crucial role in gender differences in adults but also possesses an anti-inflammatory effect on many metabolic diseases. In this study, we present a prediction of the differential proteins and signal transduction of estrogen in MIS through network pharmacology and review the validated studies on obesity, T2DM, AS, and NAFLD. Subsequently, we compared them to obtain valuable targets, identify current gaps, and provide perspectives for future research on the mechanisms of estrogen in metaflammation.

Lipoprotein Metabolism, Dyslipidemia, and Lipid-Lowering Therapy in Women: A Comprehensive Review

Lipid-lowering therapy (LLT) is a cornerstone of atherosclerotic cardiovascular disease prevention. Although LLT might lead to different reductions in low-density lipoprotein cholesterol (LDL-C) levels in women and men, LLT diminishes cardiovascular risk equally effectively in both sexes. Despite similar LLT efficacy, the use of high-intensity statins, ezetimibe, and proprotein convertase subtilisin/kexin type 9 inhibitors is lower in women compared to men. Women achieve the guideline-recommended LDL-C levels less often than men. Greater cholesterol burden is particularly prominent in women with familial hypercholesterolemia. In clinical practice, women and men with dyslipidemia present with different cardiovascular risk profiles and disease manifestations. The concentrations of LDL-C, lipoprotein(a), and other blood lipids differ between women and men over a lifetime. Dissimilar levels of LLT target molecules partially result from sex-specific hormonal and genetic determinants of lipoprotein metabolism. Hence, to evaluate a potential need for sex-specific LLT, this comprehensive review (i) describes the impact of sex on lipoprotein metabolism and lipid profile, (ii) highlights sex differences in cardiovascular risk among patients with dyslipidemia, (iii) presents recent, up-to-date clinical trial and real-world data on LLT efficacy and safety in women, and (iv) discusses the diverse medical needs of women and men with dyslipidemia and increased cardiovascular risk.

Dietary fructose regulates hepatic manganese homeostasis in female mice

Arginase, an enzyme dependent on manganese (Mn), plays a crucial role in the production of urea and processing of ammonia in the liver. Previous studies have shown that overconsumption of fructose disrupts Mn homeostasis in the liver of male mice. However, the potential sex-specific differences in the impact of fructose on hepatic Mn homeostasis remain uncertain. In this study, we provide evidence that heightened fructose intake disrupts liver Mn homeostasis in female mice. Elevated fructose exposure led to a reduction in liver Mn levels, resulting in decreased arginase and manganese superoxide dismutase (Mn-SOD) activity in the liver of female mice. The underlying mechanism involves the upregulation of carbohydrate-responsive element binding protein (ChREBP) expression and the Mn exporting gene Slc30a10 in the liver in response to fructose consumption. In summary, our findings support the involvement of fructose in liver Mn metabolism via the ChREBP/Slc30a10 pathway in female mice, and indicate that there is no disparity in the impact of fructose on hepatic Mn homeostasis between sexes.

Crosstalk interactions between transcription factors ERRα and PPARα assist PPARα-mediated gene expression

OBJECTIVE

The peroxisome proliferator-activated receptor α (PPARα) is a transcription factor driving target genes involved in fatty acid β-oxidation. To what extent various PPARα interacting proteins may assist its function as a transcription factor is incompletely understood. An ORFeome-wide unbiased mammalian protein-protein interaction trap (MAPPIT) using PPARα as bait revealed a PPARα-ligand-dependent interaction with the orphan nuclear receptor estrogen-related receptor α (ERRα). The goal of this study was to characterize the nature of the interaction in depth and to explore whether it was of physiological relevance.

METHODS

We used orthogonal protein-protein interaction assays and pharmacological inhibitors of ERRα in various systems to confirm a functional interaction and study the impact of crosstalk mechanisms. To characterize the interaction surfaces and contact points we applied a random mutagenesis screen and structural overlays. We pinpointed the extent of reciprocal ligand effects of both nuclear receptors via coregulator peptide recruitment assays. On PPARα targets revealed from a genome-wide transcriptome analysis, we performed an ERRα chromatin immunoprecipitation analysis on both fast and fed mouse livers.

RESULTS

Random mutagenesis scanning of PPARα's ligand-binding domain and coregulator profiling experiments supported the involvement of (a) bridging coregulator(s), while recapitulation of the interaction in vitro indicated the possibility of a trimeric interaction with RXRα. The PPARα·ERRα interaction depends on 3 C-terminal residues within helix 12 of ERRα and is strengthened by both PGC1α and serum deprivation. Pharmacological inhibition of ERRα decreased the interaction of ERRα to ligand-activated PPARα and revealed a transcriptome in line with enhanced mRNA expression of prototypical PPARα target genes, suggesting a role for ERRα as a transcriptional repressor. Strikingly, on other PPARα targets, including the isolated PDK4 enhancer, ERRα behaved oppositely. Chromatin immunoprecipitation analyses demonstrate a PPARα ligand-dependent ERRα recruitment onto chromatin at PPARα-binding regions, which is lost following ERRα inhibition in fed mouse livers.

CONCLUSIONS

Our data support the coexistence of multiple layers of transcriptional crosstalk mechanisms between PPARα and ERRα, which may serve to finetune the activity of PPARα as a nutrient-sensing transcription factor.

Asprosin aggravates nonalcoholic fatty liver disease via inflammation and lipid metabolic disturbance mediated by reactive oxygen species

Asprosin (ASP) is a newly-identified adipokine and plays important roles in energy metabolism homeostasis. However, there is no report on whether and how ASP is involved in the pathogenesis of nonalcoholic fatty liver disease (NAFLD). Therefore, in the study, we investigated the protective effects of ASP-deficiency on the liver in the NAFLD model mice and the detrimental effects of ASP treatment on the human normal hepatocytes (LO2 cell line). More important, we explored the underlying mechanism from the perspective of lipid metabolism and inflammation. In the in vivo experiments, our data showed that the ASP-deficiency significantly alleviated the high-fat diet-induced inflammation and NAFLD, inhibited the hepatic fat deposition and downregulated the expressions of fat acid synthase (FASN), peroxisome proliferator-activated receptor γ (PPARγ) and forkhead box protein O1 (FOXO1); moreover, the ASP-deficiency attenuated the inflammatory state and inhibited the activation of the IKK/NF-κBp65 inflammation pathway. In the in vitro experiments, our results revealed that ASP treatment caused and even exacerbated the injury of LO2 cells induced by FFA; In contrast, the ASP treatment upregulated the expressions of PPARγ, FOXO1, FASN, ACC and acyl-CoA oxidase 1 (ACOX1) and elevated the reactive oxygen species (ROS) levels. Accordingly, these results demonstrate that ASP causes NAFLD through disrupting lipid metabolism and promoting the inflammation mediated by ROS.

Exploring the "gene-metabolite" network of ischemic stroke with blood stasis and toxin syndrome by integrated transcriptomics and metabolomics strategy

A research model combining a disease and syndrome can provide new ideas for the treatment of ischemic stroke. In the field of traditional Chinese medicine, blood stasis and toxin (BST) syndrome is considered an important syndrome seen in patients with ischemic stroke (IS). However, the biological basis of IS-BST syndrome is currently not well understood. Therefore, this study aimed to explore the biological mechanism of IS-BST syndrome. This study is divided into two parts: (1) establishment of an animal model of ischemic stroke disease and an animal model of BST syndrome in ischemic stroke; (2) use of omics methods to identify differentially expressed genes and metabolites in the models. We used middle cerebral artery occlusion (MCAO) surgery to establish the disease model, and utilized carrageenan combined with active dry yeast and MCAO surgery to construct the IS-BST syndrome model. Next, we used transcriptomics and metabolomics methods to explore the differential genes and metabolites in the disease model and IS-BST syndrome model. It is found that the IS-BST syndrome model exhibited more prominent characteristics of IS disease and syndrome features. Both the disease model and the IS-BST syndrome model share some common biological processes, such as thrombus formation, inflammatory response, purine metabolism, sphingolipid metabolism, and so on. Results of the "gene-metabolite" network revealed that the IS-BST syndrome model exhibited more pronounced features of complement-coagulation cascade reactions and amino acid metabolism disorders. Additionally, the "F2 (thrombin)-NMDAR/glutamate" pathway was coupled with the formation process of the blood stasis and toxin syndrome. This study reveals the intricate mechanism of IS-BST syndrome, offering a successful model for investigating the combination of disease and syndrome.

The Effect of Menopausal Status, Insulin Resistance and Body Mass Index on the Prevalence of Non-Alcoholic Fatty Liver Disease

Non-alcoholic fatty liver disease (NAFLD) is common and presents in a large proportion-up to 30%-of the global adult female population. Several factors have been linked with NAFLD in women, such as age, obesity, and metabolic syndrome. To extract appropriate details about the topic, we conducted an extensive search using various medical subject headings and entry terms including 'Menopause', 'Non-alcoholic fatty liver disease', 'Insulin resistance', and 'BMI'. This exhaustive search resulted in a total of 180 studies, among which only 19 were able to meet the inclusion criteria. While most of these studies indicated a significant rise in NAFLD prevalence among postmenopausal women, two did not find strong evidence linking menopause with NAFLD. Moreover, it was observed that women with NAFLD had higher insulin resistance levels and BMIs compared to those without the condition. In summary, it is important to consider specific factors like risk profile, hormonal status, and age along with metabolic components when treating women presenting with NAFLD. There is need for data-driven research on how gender affects the sensitivity of biomarkers towards NAFLD as well as the development of sex-specific prediction models-this would help personalize management approaches for women, who stand to benefit greatly from such tailored interventions.

Targeting adipocyte ESRRA promotes osteogenesis and vascular formation in adipocyte-rich bone marrow

Excessive bone marrow adipocytes (BMAds) accumulation often occurs under diverse pathophysiological conditions associated with bone deterioration. Estrogen-related receptor α (ESRRA) is a key regulator responding to metabolic stress. Here, we show that adipocyte-specific ESRRA deficiency preserves osteogenesis and vascular formation in adipocyte-rich bone marrow upon estrogen deficiency or obesity. Mechanistically, adipocyte ESRRA interferes with E2/ESR1 signaling resulting in transcriptional repression of secreted phosphoprotein 1 (Spp1); yet positively modulates leptin expression by binding to its promoter. ESRRA abrogation results in enhanced SPP1 and decreased leptin secretion from both visceral adipocytes and BMAds, concertedly dictating bone marrow stromal stem cell fate commitment and restoring type H vessel formation, constituting a feed-forward loop for bone formation. Pharmacological inhibition of ESRRA protects obese mice against bone loss and high marrow adiposity. Thus, our findings highlight a therapeutic approach via targeting adipocyte ESRRA to preserve bone formation especially in detrimental adipocyte-rich bone milieu.

Androgens exacerbate hepatic triglyceride accumulation in rats with polycystic ovary syndrome by downregulating MTTP expression

PURPOSE

Polycystic ovary syndrome (PCOS) is a common reproductive endocrine disorder, which is closely associated with insulin resistance, glucose and lipid metabolism disorders. Patients with PCOS have a significantly higher risk of non-alcoholic fatty liver disease and are associated with hyperandrogenemia (HA). However, the exact mechanism by which HA exacerbates hepatic steatosis in PCOS has not yet been fully elucidated. This work aims to investigate the effects and underlying mechanisms of androgens on hepatic triglyceride (TG) metabolism in rats with PCOS.

METHODS

Twenty-four female Sprague-Dawley rats were randomly divided into four groups (6 rats/group): control, high-fat diet (HFD), PCOS, and PCOS + flutamide (Flu). Changes in the estrous cycle, liver and ovarian tissue sections, serum total testosterone, serum and liver biochemical indicators, and key enzymes involved in TG metabolism were studied.

RESULTS

Hepatocyte steatosis and TG accumulation were more evident in the PCOS group than in the control and HFD groups. The PCOS group showed apparent increases in the levels of serum alanine aminotransferase, aspartate aminotransferase, TG, free fatty acid, fasting insulin, and homeostasis model assessment of insulin resistance. Hepatic VLDL and apoB-100 levels decreased in the PCOS group. After Flu was administered to block the actions of androgens, the above abnormalities had been improved. The expression of MTTP was greatly decreased in the PCOS group and significantly increased after Flu administration.

CONCLUSION

Hepatic steatosis in PCOS rats was correlated with HA. Androgens may exacerbate hepatic TG accumulation by downregulating MTTP expression in PCOS.

Estrogen related receptor alpha: Potential modulator of age-related macular degeneration

To develop effective therapies for complex blinding diseases such as age-related macular degeneration (AMD), identification of mechanisms involved in its initiation and progression is needed. The estrogen-related receptor alpha (ESRRA) is an orphan nuclear receptor that regulates several AMD-associated pathogenic pathways. However, it has not been investigated in detail in the ocular posterior pole during aging or in AMD. This review delves into the literature highlighting the significance of ESRRA as a molecular target that may be important in the pathobiology of AMD, and discusses data available supporting the targeting of this receptor signaling pathway as a therapeutic option for AMD.

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 treatment 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.

Association between the ZJU index and risk of new-onset non-alcoholic fatty liver disease in non-obese participants: a Chinese longitudinal prospective cohort study

Background

Non-alcoholic fatty liver disease (NAFLD) is increasingly observed in non-obese individuals. The ZJU (Zhejiang University) index has been established as a new and efficient tool for detecting NAFLD, but the relationship between the ZJU index and NAFLD within non-obese individuals still remains unclear.

Methods

A post-hoc evaluation was undertaken using data from a health assessment database by the Wenzhou Medical Center. The participants were divided into four groups based on the quartile of the ZJU Index. Cox proportional hazards regression, Kaplan-Meier analysis and tests for linear trends were used to evaluate the relationship between the ZJU index and NAFLD incidence. Subgroup analysis was conducted to test the consistency of the correlation between ZJU and NAFLD in subsgroups. Receiver operative characteristic (ROC) curve analysis was performed to evaluate the predictive performance of the ZJU index, compared with the Atherogenic index of plasma (AIP) and Remnant lipoprotein cholesterol (RLP-C) index.

Results

A total of 12,127 were included in this study, and 2,147 participants (17.7%) developed NAFLD in 5 years follow-up. Participants in higher ZJU quartiles tended to be female and have higher liver enzymes (including ALP, GGT, ALT, AST), GLU, TC, TG, LDL and higher NAFLD risk. Hazard Ratios (HR) and 95% confidence intervals (CI) for new-onset NAFLD in Q2, Q3, and Q4 were 3.67(2.43 to 5.55), 9.82(6.67 to 14.45), and 21.67(14.82 to 31.69) respectively in the fully adjusted model 3. With increased ZJU index, the cumulative new-onset NAFLD gradually increased. Significant linear associations were observed between the ZJU index and new-onset NAFLD (p for trend all<0.001). In the subgroup analysis, we noted a significant interaction in sex, with HRs of 3.27 (2.81, 3.80) in female and 2.41 (2.21, 2.63) in male (P for interaction<0.01). The ZJU index outperformed other indices with an area under the curve (AUC) of 0.823, followed by AIP (AUC=0.747) and RLP-C (AUC=0.668).

Conclusion

The ZJU index emerges as a promising tool for predicting NAFLD risk in non-obese individuals, outperforming other existing parameters including AIP and RLP-C. This could potentially aid in early detection and intervention in this specific demographic.

Lower creatinine to cystatin C ratio is associated with an increased risk of MASLD: A cross-sectional and prospective study of 368,634 UK Biobank participants

OBJECTIVE

Metabolic dysfunction-associated steatotic liver disease (MASLD) affects many populations, and screening out the high-risk populations at an early stage is a challenge. As a sarcopenia index, the relationship between creatinine to cystatin C ratio (CCR) and MASLD remains unclear. This cross-sectional, prospective study aimed to explore the relationship between CCR and MASLD. Design Firstly, explored the correlation between CCR and MASLD in cross-sectional analyses. Then excluded the population with baseeline diagnosis of MASLD and analyzed the association with baseline CCR levels and the onset of MASLD in the population with available follow-up data. Univariate and multivariate logistic regression analyses were used to calculate odds ratios (ORs) to evaluate the association between CCR levels and MASLD.

PATIENTS AND MEASUREMENTS

This study included 368,634 participants from the UK Biobank for cross-sectional and prospective analyses. The demographic characteristics and laboratory measurements of all participants were obtained from the UK Biobank. MASLD was diagnosed according to the multi-society consensus nomenclature. Hepatic steatosis was defined as FLI  ≥60.

RESULTS

We grouped the study participants according to CCR tertiles. In cross-sectional analyses, participants in CCR tertile 1 had the highest MASLD risk (OR: 1.070, 95% CI: 1.053-1.088, p < .001). And the similar association was observed in the prospective analyses (CCR tertile 1 OR: 1.340, 95% CI: 1.077-1.660, p = .009; CCR tertile 2 OR: 1.217, 95% CI: 1.021-1.450, p = .029, respectively). After stratification by gender, the significant association between CCR and the onset of MASLD was only observed in males (CCR tertile 1 OR: 1.639, 95% CI: 1.160-2.317, p = .005; CCR tertile 2 OR: 1.322, 95% CI: 1.073-1.628, p = .005, respectively).

CONCLUSION

Our results indicated that lower CCR was significantly associated with higher risk of MASLD, based on which predictive models can be developed to screen populations at high risk of developing MASLD.

Enhancing aortic valve drug delivery with PAR2-targeting magnetic nano-cargoes for calcification alleviation

Calcific aortic valve disease is a prevalent cardiovascular disease with no available drugs capable of effectively preventing its progression. Hence, an efficient drug delivery system could serve as a valuable tool in drug screening and potentially enhance therapeutic efficacy. However, due to the rapid blood flow rate associated with aortic valve stenosis and the lack of specific markers, achieving targeted drug delivery for calcific aortic valve disease has proved to be challenging. Here we find that protease-activated-receptor 2 (PAR2) expression is up-regulated on the plasma membrane of osteogenically differentiated valvular interstitial cells. Accordingly, we develop a magnetic nanocarrier functionalized with PAR2-targeting hexapeptide for dual-active targeting drug delivery. We show that the nanocarriers effectively deliver XCT790-an anti-calcification drug-to the calcified aortic valve under extra magnetic field navigation. We demonstrate that the nano-cargoes consequently inhibit the osteogenic differentiation of valvular interstitial cells, and alleviate aortic valve calcification and stenosis in a high-fat diet-fed low-density lipoprotein receptor-deficient (Ldlr-/-) mouse model. This work combining PAR2- and magnetic-targeting presents an effective targeted drug delivery system for treating calcific aortic valve disease in a murine model, promising future clinical translation.

The roles of nuclear receptors in cholesterol metabolism and reverse cholesterol transport in nonalcoholic fatty liver disease

As the most prevalent chronic liver disease globally, NAFLD encompasses a pathological process that ranges from simple steatosis to NASH, fibrosis, cirrhosis, and HCC, closely associated with numerous extrahepatic diseases. While the initial etiology was believed to be hepatocyte injury caused by lipid toxicity from accumulated triglycerides, recent studies suggest that an imbalance of cholesterol homeostasis is of greater significance. The role of nuclear receptors in regulating liver cholesterol homeostasis has been demonstrated to be crucial. This review summarizes the roles and regulatory mechanisms of nuclear receptors in the 3 main aspects of cholesterol production, excretion, and storage in the liver, as well as their cross talk in reverse cholesterol transport. It is hoped that this review will offer new insights and theoretical foundations for the study of the pathogenesis and progression of NAFLD and provide new research directions for extrahepatic diseases associated with NAFLD.

Correlation Between Lipoprotein-Related Phospholipase A2 and Metabolic Syndrome

Background

Lipoprotein-associated phospholipase A2 (Lp-PLA2) has been recognized as a valuable biomarker for identifying the risk of cardiovascular diseases and inflammation. Furthermore, there is strong evidence to suggest that metabolic syndrome is closely associated with chronic inflammation. Accordingly, the present study endeavors to examine the potential correlation between metabolic syndrome and the levels of Lp-PLA2.

Methods

To explore the relationship between Lp-PLA2 levels and metabolic syndrome, and to establish the predictive cut-off value of Lp-PLA2, a retrospective analysis was conducted using medical data from a sample of 3549 Chinese adults (comprising 2182 men and 1367 women) aged between 18 and 50 years, who had undergone health check-ups. In addition, the study also sought to investigate any potential differences in Lp-PLA2 levels based on sex and age.

Results

The analysis of the data indicated that participants had a mean age of 44.2 years, a mean Lp-PLA2 level of 589 IU/L, and a metabolic syndrome prevalence of 22%. Lp-PLA2 levels were significantly different between males and females, and a significant correlation was observed between Lp-PLA2 levels and clinical and metabolic characteristics, including BMI, cholesterol, and triglycerides. Interestingly, Lp-PLA2 demonstrated potential as an indicator of metabolic syndrome, particularly in females, despite other biomarkers, such as TG/HDL-C and WHR, exhibiting better area under the curve.

Conclusion

Our findings suggest that Lp-PLA2 may serve as a useful biomarker for identifying individuals at risk of developing metabolic syndrome, particularly in females. Further research is needed to explore the potential of Lp-PLA2 as a diagnostic and therapeutic target for metabolic syndrome.

17β-Estradiol (E2) Upregulates the ERα/SIRT1/PGC-1α Signaling Pathway and Protects Mitochondrial Function to Prevent Bilateral Oophorectomy (OVX)-Induced Nonalcoholic Fatty Liver Disease (NAFLD)

Premature menopause is associated with an increased prevalence of nonalcoholic fatty liver disease (NAFLD). Menopausal hormone therapy (MHT) has been widely used in clinical practice and has the potential to protect mitochondrial function and alleviate NAFLD. After bilateral oophorectomy (OVX), female rats without 17β-estradiol (E2) intervention developed NAFLD, whereas E2 supplementation was effective in preventing NAFLD in female rats. The altered pathways and cellular events from both comparison pairs, namely, the OVX vs. sham group and the OVX vs. E2 group, were assessed using transcriptomic analysis. KEGG pathways enriched by both transcriptomic and metabolomic analyses strongly suggest that oxidative phosphorylation is a vital pathway that changes during the development of NAFLD and remains unchanged when E2 is applied. Liver tissue from the OVX-induced NAFLD group exhibited increased lipid peroxidation, impaired mitochondria, and downregulated ERα/SIRT1/PGC-1α expression. An in vitro study indicated that the protective effect of E2 treatment on hepatic steatosis could be abolished when ERα or SIRT1 was selectively inhibited. This damage was accompanied by reduced mitochondrial complex activity and increased lipid peroxidation. The current research indicates that E2 upregulates the ERα/SIRT1/PGC-1α signaling pathway and protects mitochondrial function to prevent OVX-induced NAFLD.

Unmasking the enigma of lipid metabolism in metabolic dysfunction-associated steatotic liver disease: from mechanism to the clinic

Metabolic dysfunction-associated steatotic liver disease (MASLD), formerly defined as non-alcoholic fatty liver disease (NAFLD), is a disorder marked by the excessive deposition of lipids in the liver, giving rise to a spectrum of liver pathologies encompassing steatohepatitis, fibrosis/cirrhosis, and hepatocellular carcinoma. Despite the alarming increase in its prevalence, the US Food and Drug Administration has yet to approve effective pharmacological therapeutics for clinical use. MASLD is characterized by the accretion of lipids within the hepatic system, arising from a disarray in lipid provision (whether through the absorption of circulating lipids or de novo lipogenesis) and lipid elimination (via free fatty acid oxidation or the secretion of triglyceride-rich lipoproteins). This disarray leads to the accumulation of lipotoxic substances, cellular pressure, damage, and fibrosis. Indeed, the regulation of the lipid metabolism pathway is intricate and multifaceted, involving a myriad of factors, such as membrane transport proteins, metabolic enzymes, and transcription factors. Here, we will review the existing literature on the key process of lipid metabolism in MASLD to understand the latest progress in this molecular mechanism. Notably, de novo lipogenesis and the roles of its two main transcription factors and other key metabolic enzymes are highlighted. Furthermore, we will delve into the realm of drug research, examining the recent progress made in understanding lipid metabolism in MASLD. Additionally, we will outline prospective avenues for future drug research on MASLD based on our unique perspectives.

Pancreastatin deteriorates hepatic lipid metabolism via elevating fetuin B in ovariectomized rats

Hepatic steatosis is an important mstetabolic complication in women encountering postmenopausal phase of life. Pancreastatin (PST), has previously been investigated in diabetic and insulin resistant rodents. The present study highlighted the role of PST in ovariectomized rats. Female SD rats were ovariectomized and subsequently fed high fructose diet for 12 weeks. PST inhibitor peptide was intraperitoneally administered for 14 days and further examined for insulin resistance, glucose intolerance development, body mass composition, lipid profile detection and hepatic fibrosis. Gut microbial alterations has also been investigated. Results showed development of glucose intolerance in high fructose fed ovariectomized rats with reduced level of reproductive hormones including estradiol and progesterone. Enhanced lipid production was detected in these rats as they showed increased triglycerides, lipid accumulation in liver tissue (determined by HE staining, Oil Red O staining, Nile Red staining). Sirius Red and Masson's trichome analysis depicted positive results for fibrosis development. We also found gut microbiota alterations in fecal samples of these rats. Furthermore, PST inhibition decreased the expression of hepatic Fetuin B and resumed gut microbial diversity. PST deregulates hepatic lipid metabolism which leads to altered expression of Fetuin B in liver and gut dysbiosis in postmenopausal rats.

Sex- and reproductive status-specific relationships between body composition and non-alcoholic fatty liver disease

BACKGROUND

Sex and reproductive status differences exist in both non-alcoholic fatty liver disease (NAFLD) and body composition. Our purpose was to investigate the relationship between body composition and the severity of liver steatosis and fibrosis in NAFLD in different sex and reproductive status populations.

METHODS

This cross-sectional study included 880 patients (355 men, 417 pre-menopausal women, 108 post-menopausal women). Liver steatosis and fibrosis and body composition data were measured using FibroScan and a bioelectrical impedance body composition analyzer (BIA), respectively, and the following parameters were obtained: liver stiffness measurement (LSM), controlled attenuation parameter (CAP), waist circumference (WC), body mass index (BMI), percent body fat (PBF), visceral fat area (VFA), appendicular skeletal muscle mass (ASM), appendicular skeletal muscle mass index (ASMI), fat mass (FM), fat free mass (FFM), and FFM to FM ratio (FFM/FM). Multiple ordinal logistic regression (MOLR) was used to analyze the independent correlation between body composition indicators and liver steatosis grade and fibrosis stage in different sex and menopausal status populations.

RESULTS

Men had higher WC, ASM, ASMI, FFM, and FFM/FM than pre- or post-menopausal women, while pre-menopausal women had higher PBF, VFA, and FM than the other two groups (p < 0.001). Besides, men had greater CAP and LSM values (p < 0.001). For MOLR, after adjusting for confounding factors, WC (OR, 1.07; 95% CI, 1.02-1.12; P = 0.011) and FFM/FM (OR, 0.52; 95% CI, 0.31-0.89; P = 0.017) in men and visceral obesity (OR, 4.16; 95% CI, 1.09-15.90; P = 0.037) in post-menopausal women were independently associated with liver steatosis grade. WC and visceral obesity were independently associated with liver fibrosis stage in men (OR, 1.05; 95% CI, 1.01-1.09, P = 0.013; OR, 3.92; 95% CI, 1.97-7.81; P < 0.001, respectively).

CONCLUSIONS

Increased WC and low FFM/FM in men and visceral obesity in post-menopausal women were independent correlates of more severe liver steatosis. In addition, increased WC and visceral obesity were independent correlates of worse liver fibrosis in men. These data support the sex- and reproductive status-specific management of NAFLD.

Sex differences in the association between adipose insulin resistance and non-alcoholic fatty liver disease in Chinese adults

BACKGROUND

Adipose insulin resistance (Adipo-IR) is associated with multiple metabolic diseases, including non-alcoholic fatty liver disease (NAFLD). The study aimed to evaluate sex differences in the association between Adipo-IR and NAFLD, and further investigated other potential modifiers.

METHODS

This cross-sectional study enrolled adults without diabetes who underwent physical examinations in Beijing Chao-Yang Hospital. We calculated the Adipo-IR index as the product of the fasting insulin and free fatty acid concentration. We categorized Adipo-IR into four groups according to quartiles, using the first interquartile range (Q1) as the reference. Logistic regression was used stratified by the modifiers after adjustment for potential confounders.

RESULTS

There were 5586 participants in the study, 49.8% (n = 2781) of whom were women and 30.4% (n = 1698) with NAFLD. There was a graded positive association between Adipo-IR and NAFLD, with sex (P = 0.01) and hyperlipidemia (P = 0.02) modifying this association. In the hyperlipidemic women, for one unit increase in log-Adipo-IR, the odds of having NAFLD increased by 385% after adjustment for potential confounders (OR = 4.85, 95%CI 3.54-6.73, P < 0.001). However, it turned out that the odds of having NAFLD increased by 131% (OR = 2.31, 95%CI 1.74-3.11, P < 0.001), 216% (OR = 3.16, 95%CI 2.56-3.93, P < 0.001), 181% (OR = 2.81, 95%CI 1.88-4.28, P < 0.001) in normolipidemic men, hyperlipidemic men, and normolipidemic women, respectively. Similarly, the ORs for the association between Adipo-IR and NAFLD in women with age ≥ 50 years were higher than ORs in women with age < 50 years.

CONCLUSIONS

The positive correlation between Adipo-IR and NAFLD was stronger in hyperlipidemic women, compared with normolipidemic or hyperlipidemic men, or normolipidemic women. The association also strengthened for women over 50 years. Treatment strategies targeting Adipo-IR to alleviate NAFLD may be of value, especially in hyperlipidemic women after menopause.

Relationship between nonalcoholic fatty liver disease and bone mineral density in elderly Chinese

OBJECTIVE

As our society grows older, both bone loss and fatty liver have become important issues. However, the relationship between reduced bone mineral density and fatty liver remains controversial. The purpose of this study was to investigate the relationship between nonalcoholic fatty liver disease and less bone mineral density in the ankles of Chinese people over 65.

METHODS

The research included 716 older adults over the age of 65 who underwent a comprehensive health screening. A logistic regression model was used to investigate the relationship between nonalcoholic fatty liver disease (NAFLD) and ankle bone mineral density.

RESULTS

A logistic regression model was used to analyze the odds ratios of reduced bone mineral density between patients with fatty liver and controls. In the adjusted model, adjustments were made for age, sex, systolic blood pressure, diastolic blood pressure, overweight rate, history of hypertension, history of diabetes, history of smoking, history of alcohol consumption, fasting glucose, hemoglobin, urea, creatinine, triglycerides, total cholesterol, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, waist circumference, total protein, albumin, and globulin. The adjusted OR (aOR) for reduced bone mineral density was 0.66 [95% confidence interval (CI) = 0.45-0.97, P = 0.034 < 0.05]. In subgroup analysis by age, sex, and BMI, women, age > 75 years, and BIM < 25 were statistically significant.

CONCLUSION

This study suggested that NAFLD is associated with a reduced risk of reduced heel bone mass. More research needs to be done to back up the results of this study and look into possible problems.

Sex-Specific Differences in Lipoprotein Production and Clearance

Therapeutic approaches to reduce atherogenic lipid and lipoprotein levels remain the most effective and assessable strategies to prevent and treat cardiovascular disease. The discovery of novel research targets linked to pathways associated with cardiovascular disease development has enhanced our ability to decrease disease burden; however, residual cardiovascular disease risks remain. Advancements in genetics and personalized medicine are essential to understand some of the factors driving residual risk. Biological sex is among the most relevant factors affecting plasma lipid and lipoprotein profiles, playing a pivotal role in the development of cardiovascular disease. This minireview summarizes the most recent preclinical and clinical studies covering the effect of sex on plasma lipid and lipoprotein levels. We highlight the recent advances in the mechanisms regulating hepatic lipoprotein production and clearance as potential drivers of disease presentation. We focus on using sex as a biological variable in studying circulating lipid and lipoprotein levels.

Nonalcoholic Fatty Liver Disease and Omega-3 Fatty Acids: Mechanisms and Clinical Use

Nonalcoholic fatty liver disease (NAFLD) is the most common chronic fatty liver disease worldwide, particularly in obese and type 2 diabetic individuals. Currently, there are no therapies for NAFLD that have been approved by the US Food and Drug Administration. Herein, we examine the rationale for using ω3 polyunsaturated fatty acids (PUFAs) in NAFLD therapy. This focus is based on the finding that NAFLD severity is associated with a reduction of hepatic C20-22 ω3 PUFAs. Because C20-22 ω3 PUFAs are pleiotropic regulators of cell function, loss of C20-22 ω3 PUFAs has the potential to significantly impact hepatic function. We describe NAFLD prevalence and pathophysiology as well as current NAFLD therapies. We also present evidence from clinical and preclinical studies that evaluated the capacity of C20-22 ω3 PUFAs to treat NAFLD. Given the clinical and preclinical evidence, dietary C20-22 ω3 PUFA supplementation has the potential to decrease human NAFLD severity by reducing hepatosteatosis and liver injury.

Roles of N6-methyladenosine epitranscriptome in non-alcoholic fatty liver disease and hepatocellular carcinoma

Non-alcoholic fatty liver disease (NAFLD) is a typical chronic liver disease connected to a high risk of developing hepatocellular carcinoma (HCC). The development of NAFLD and HCC has been associated with changes in epigenetics, such as histone modifications and micro RNA (miRNA)-mediated processes. Recently, in the realm of epitranscriptomics, RNA alterations have become important regulators. N6-methyladenosine (m6A) is the most common and crucial alteration for controlling mRNA stability, splicing, and translation. It is particularly important for controlling liver disease progression and hepatic function. This review aims to conclude recent research on the functions of m6A epitranscriptome in the molecular mechanisms behind NAFLD and HCC development, with special attention to the effects of m6A alteration on how HCC develops and its possible roles in the progression of NAFLD to HCC. Additionally, the review discusses the possible effects of m6A alteration on the treatment and diagnostic of NAFLD and HCC. It is crucial to remember that m6A modification is a reversible action controlled via the coordinated functions of the proteins that write and delete, enabling quick adaptability to environmental changes. The review also discusses m6A-binding proteins' function in mRNA alternative splicing, translation, and degradation and their ability to modulate mRNA stability and processing. Understanding RNA modification regulation and its part in the emergence of HCC and NAFLD may provide new avenues for diagnosing and treating these diseases.

Immunomodulatory role of estrogen in ischemic stroke: neuroinflammation and effect of sex

Although estrogen is predominantly related to the maintenance of reproductive functioning in females, it mediates various physiological effects in nearly all tissues, especially the central nervous system. Clinical trials have revealed that estrogen, especially 17β-estradiol, can attenuate cerebral damage caused by an ischemic stroke. One mechanism underlying this effect of 17β-estradiol is by modulating the responses of immune cells, indicating its utility as a novel therapeutic strategy for ischemic stroke. The present review summarizes the effect of sex on ischemic stroke progression, the role of estrogen as an immunomodulator in immune reactions, and the potential clinical value of estrogen replacement therapy. The data presented here will help better understand the immunomodulatory function of estrogen and may provide a basis for its novel therapeutic use in ischemic stroke.

Deleting Gata4 in hepatocytes promoted the progression of NAFLD via increasing steatosis and apoptosis, and desensitizing insulin signaling

Gata4 is a member of the zinc finger GATA transcription factor family and is required for liver development during the embryonic stage. Gata4 expression is repressed during NAFLD progression, however how it functions in this situation remains unclear. Here, Gata4 was deleted specifically in hepatocytes via Cre recombinase driven by the Alb promoter region. Under a high-fat diet (HFD) or methionine and choline deficient diet (MCD), Gata4 knockout (KO) male, but not female, mice displayed more severe NAFLD or NASH, evidenced by increased steatosis, fibrosis, as well as a higher NAS score and serum ALT level. The Gata4KO male liver exposed to a HFD or MCD had a reduced ratio of pACC/ACC, similar to the Gata4KO hepatocytes treated with palmitic acid. More cell apoptosis, which is associated with activated JNK signaling and inhibited NFκB signaling, was observed in the Gata4KO male liver and isolated hepatocytes. However, the inflammatory status in the Gata4KO male liver was similar to the control liver. Importantly, lower activation of AKT signaling in the liver, which is consistent with de-sensitized insulin signaling in isolated hepatocytes, was found in the Gata4KO male. In summary, our data demonstrated that loss of Gata4 in hepatocytes promoted NAFLD progression in male mice.

Metal mixtures with longitudinal changes in lipid profiles: findings from the manganese-exposed workers healthy cohort

The majority of epidemiological investigations on metal exposures and lipid metabolism employed cross-sectional designs and focused on individual metal. We explored the associations between metal mixture exposures and longitudinal changes in lipid profiles and potential sexual heterogeneity. We recruited 250 men and 73 women, aged 40 years at baseline (2012), and followed them up in 2020, from the manganese-exposed workers healthy cohort. We detected metal concentrations of blood cells at baseline with inductively coupled plasma mass spectrometry. Lipid profiles were repeatedly measured over 8 years of follow-up. We performed sparse partial least squares (sPLS) model to evaluate multi-pollutant associations. Bayesian kernel machine regression was utilized for metal mixtures as well as evaluating their joint impacts on lipid changes. In sPLS models, a positive association was found between manganese and change in total cholesterol (TC) (beta = 0.169), while a negative association was observed between cobalt (beta =  - 0.134) and change in low density lipoprotein cholesterol (LDL-C) (beta =  - 0.178) among overall participants, which were consistent in men. Interestingly, rubidium was positively associated with change in LDL-C (beta = 0.273) in women, while copper was negatively associated with change in TC (beta =  - 0.359) and LDL-C (beta =  - 0.267). Magnesium was negatively associated with change in TC (beta =  - 0.327). We did not observe the significantly cumulative effect of metal mixtures on lipid changes. In comparison to other metals, manganese had a more significant influence on lipid change [group PIP (0.579) and conditional PIP (0.556) for TC change in men]. Furthermore, male rats exposed to manganese (20 mg/kg) had higher levels of LDL-C in plasma and more apparent inflammatory infiltration, vacuolation of liver cells, nuclear pyknosis, and fatty change than the controls. These findings highlight the potential role of metal mixtures in lipid metabolism with sex-dependent heterogeneity. More researches are needed to explore the underlying mechanisms.

The prevalence of MAFLD and its association with atrial fibrillation in a nationwide health check-up population in China

BACKGROUND AND AIMS

The epidemiological characteristics of MAFLD and its relationship with atrial fibrillation (AF) are limited in China. Therefore, we explored the epidemiological characteristics of MAFLD from adults along with the association of MAFLD and 12-ECG diagnosed AF in a nationwide population from health check-up centers.

METHODS

This observational study used cross-sectional and longitudinal studies with 2,083,984 subjects from 2009 to 2017. Age-, sex-, and regional-standardized prevalence of MAFLD was estimated. Latent class analysis (LCA) was used to identify subclusters of MAFLD. Multivariable logistic regression and mixed-effects Cox regression models were used to analyze the relationship between MAFLD and AF.

RESULTS

The prevalence of MAFLD increased from 22.75% to 35.58% during the study period, with higher rates in males and populations with high BMI or resided in northern regions. The MAFLD population was clustered into three classes with different metabolic features by LCA. Notably, a high proportion of MAFLD patients in all clusters had overweight and prediabetes or diabetes. The MAFLD was significantly associated with a higher risk of AF in the cross-sectional study and in the longitudinal study. In addition, the coexistence of prediabetes or diabetes had the largest impact on subsequent AF.

CONCLUSION

Our findings suggested a high prevalence of MAFLD and a high prevalence of other metabolic diseases in the MAFLD population, particularly overweight and glucose dysregulation. Moreover, MAFLD was associated with a significantly higher risk for existing and subsequent subclinical AF in the Chinese population.

Chemotactic cytokines secreted from Kupffer cells contribute to the sex-dependent susceptibility to non-alcoholic fatty liver diseases in mice

AIMS

The global prevalence of non-alcoholic fatty liver disease (NAFLD) has rapidly increased over the last decade due to an elevated occurrence of metabolic syndromes. Importantly, the prevalence and severity of NAFLD is higher in men than in women. Therefore, in the present study we endeavored to identify the mechanistic disparity between male and female mice.

MAIN METHODS

Global gene transcriptomics analysis was done with the high-fat diet (HFD)-induced NAFLD model of male, female, and ovariectomized (OVX) female mice. The expression of CCL2, CXCL2, and CXCL10 in mRNA level and serum protein level was done by qPCR and ELISA each. Immunohistochemistry staining was used to observe hepatic immune cell infiltration. To analyzing portion of immune cells, flow cytometry was done with isolated liver cells from HFD-fed male and female mice. Primary mouse liver cells were isolated from male and female mice for in vitro studies.

KEY FINDINGS

We identified sex differences in inflammatory chemokines, CCL2, CXCL2, and CXCL10, with the expression of these chemokines enhanced in male and OVX, but not in female, mice after HFD feeding. Resident Kupffer cells (KCs) were identified as the major source of production of CCL2, CXCL2, and CXCL10 in the mouse NAFLD model. Notably, KCs obtained from male mice expressed higher levels of chemokines than those from female mice, indicating that KCs may mediate the sex discrepancy in NAFLD progression.

SIGNIFICANCE

Our findings offer new insights into the pathology of sex-specific differences in NAFLD, involving chemokines and KCs.

Estrogen-related receptor alpha in select host functions and cancer: new frontiers

Eukaryotic gene expression is under the tight control of transcription factors, which includes the estrogen-related receptor alpha (ERRα). The endogenous ligand(s) acting as ERRα agonist has not been identified and confirmed. ERRα is a prominent member of the nuclear receptors super-family with major roles in energy metabolism, including immunity, cell growth, proliferation and differentiation and a host of other functions in animals. The actions exerted by ERRα towards gene expression regulation are often in association with other transcriptional factors, receptors and signal mediators. Metabolic regulation by ERRα is known for some time that has tremendous impact on host biology like autophagy, angiogenesis, mitochondrial activity, including lipid metabolism. Cellular metabolism and cancer has intricate relationship. On account of the participation of ERRα in metabolism, it has been implicated in various types of cancer onset and progression. In a number of findings, ERRα has been demonstrated to influence several types of cancers, exhibiting as a negative prognostic marker for many. Such diverse role associated with ERRα is due to its interaction with numerous transcriptional factors and other signalling pathways that culminate in providing optimal gene regulation. These observations points to the crucial regulatory roles of ERRα in health and disease. In this article, some of the new findings on the influence of ERRα in host metabolism and biology including cancer, shall be reviewed that will provide a concise understanding of this receptor.

Insulin action and resistance are dependent on a GSK3β-FBXW7-ERRα transcriptional axis

Insulin resistance, a harbinger of the metabolic syndrome, is a state of compromised hormonal response resulting from the dysregulation of a wide range of insulin-controlled cellular processes. However, how insulin affects cellular energy metabolism via long-term transcriptional regulation and whether boosting mitochondrial function alleviates insulin resistance remains to be elucidated. Herein we reveal that insulin directly enhances the activity of the nuclear receptor ERRα via a GSK3β/FBXW7 signaling axis. Liver-specific deletion of GSK3β or FBXW7 and mice harboring mutations of ERRα phosphosites (ERRα3SA) co-targeted by GSK3β/FBXW7 result in accumulated ERRα proteins that no longer respond to fluctuating insulin levels. ERRα3SA mice display reprogrammed liver and muscle transcriptomes, resulting in compromised energy homeostasis and reduced insulin sensitivity despite improved mitochondrial function. This crossroad of insulin signaling and transcriptional control by a nuclear receptor offers a framework to better understand the complex cellular processes contributing to the development of insulin resistance.

Emerging Evidence of Pathological Roles of Very-Low-Density Lipoprotein (VLDL)

Embraced with apolipoproteins (Apo) B and Apo E, triglyceride-enriched very-low-density lipoprotein (VLDL) is secreted by the liver into circulation, mainly during post-meal hours. Here, we present a brief review of the physiological role of VLDL and a systemic review of the emerging evidence supporting its pathological roles. VLDL promotes atherosclerosis in metabolic syndrome (MetS). VLDL isolated from subjects with MetS exhibits cytotoxicity to atrial myocytes, induces atrial myopathy, and promotes vulnerability to atrial fibrillation. VLDL levels are affected by a number of endocrinological disorders and can be increased by therapeutic supplementation with cortisol, growth hormone, progesterone, and estrogen. VLDL promotes aldosterone secretion, which contributes to hypertension. VLDL induces neuroinflammation, leading to cognitive dysfunction. VLDL levels are also correlated with chronic kidney disease, autoimmune disorders, and some dermatological diseases. The extra-hepatic secretion of VLDL derived from intestinal dysbiosis is suggested to be harmful. Emerging evidence suggests disturbed VLDL metabolism in sleep disorders and in cancer development and progression. In addition to VLDL, the VLDL receptor (VLDLR) may affect both VLDL metabolism and carcinogenesis. Overall, emerging evidence supports the pathological roles of VLDL in multi-organ diseases. To better understand the fundamental mechanisms of how VLDL promotes disease development, elucidation of the quality control of VLDL and of the regulation and signaling of VLDLR should be indispensable. With this, successful VLDL-targeted therapies can be discovered in the future.

Engineering stem cells to produce exosomes with enhanced bone regeneration effects: an alternative strategy for gene therapy

BACKGROUND

Exosomes derived from stem cells have been widely studied for promoting regeneration and reconstruction of multiple tissues as "cell-free" therapies. However, the applications of exosomes have been hindered by limited sources and insufficient therapeutic potency.

RESULTS

In this study, a stem cell-mediated gene therapy strategy is developed in which mediator mesenchymal stem cells are genetically engineered by bone morphogenetic protein-2 gene to produce exosomes (MSC-BMP2-Exo) with enhanced bone regeneration potency. This effect is attributed to the synergistic effect of the content derived from MSCs and the up-regulated BMP2 gene expression. The MSC-BMP2-Exo also present homing ability to the injured site. The toxic effect of genetical transfection vehicles is borne by mediator MSCs, while the produced exosomes exhibit excellent biocompatibility. In addition, by plasmid tracking, it is interesting to find a portion of plasmid DNA can be encapsulated by exosomes and delivered to recipient cells.

CONCLUSIONS

In this strategy, engineered MSCs function as cellular factories, which effectively produce exosomes with designed and enhanced therapeutic effects. The accelerating effect in bone healing and the good biocompatibility suggest the potential clinical application of this strategy.

Fluoxetine-induced hepatic lipid accumulation is mediated by prostaglandin endoperoxide synthase 1 and is linked to elevated 15-deoxy-Δ12,14 PGJ2

Major depressive disorder and other neuropsychiatric disorders are often managed with long-term use of antidepressant medication. Fluoxetine, an SSRI antidepressant, is widely used as a first-line treatment for neuropsychiatric disorders. However, fluoxetine has also been shown to increase the risk of metabolic diseases such as non-alcoholic fatty liver disease. Fluoxetine has been shown to increase hepatic lipid accumulation in vivo and in vitro. In addition, fluoxetine has been shown to alter the production of prostaglandins which have also been implicated in the development of non-alcoholic fatty liver disease. The goal of this study was to assess the effect of fluoxetine exposure on the prostaglandin biosynthetic pathway and lipid accumulation in a hepatic cell line (H4-II-E-C3 cells). Fluoxetine treatment increased mRNA expression of prostaglandin biosynthetic enzymes (Ptgs1, Ptgs2, and Ptgds), PPAR gamma (Pparg), and PPAR gamma downstream targets involved in fatty acid uptake (Cd36, Fatp2, and Fatp5) as well as production of 15-deoxy-Δ^12,14 PGJ₂ a PPAR gamma ligand. The effects of fluoxetine to induce lipid accumulation were attenuated with a PTGS1 specific inhibitor (SC-560), whereas inhibition of PTGS2 had no effect. Moreover, SC-560 attenuated 15-deoxy-Δ^12,14 PGJ₂ production and expression of PPAR gamma downstream target genes. Taken together these results suggest that fluoxetine-induced lipid abnormalities appear to be mediated via PTGS1 and its downstream product 15d-PGJ₂ and suggest a novel therapeutic target to prevent some of the adverse effects of fluoxetine treatment.

Lipid Disorders in NAFLD and Chronic Kidney Disease

Nonalcoholic fatty liver disease (NAFLD) is the most common cause of chronic liver dysfunction and is characterized by exaggerated lipid accumulation, inflammation and even fibrosis. It has been shown that NAFLD increases the risk of other chronic diseases, particularly chronic kidney disease (CKD). Lipid in excess could lead to liver and kidney lesions and even end-stage disease through diverse pathways. Dysregulation of lipid uptake, oxidation or de novo lipogenesis contributes to the toxic effects of ectopic lipids which promotes the development and progression of NAFLD and CKD via triggering oxidative stress, apoptosis, pro-inflammatory and profibrotic responses. Importantly, dyslipidemia and release of pro-inflammatory cytokines caused by NAFLD (specifically, nonalcoholic steatohepatitis) are considered to play important roles in the pathological progression of CKD. Growing evidence of similarities between the pathogenic mechanisms of NAFLD and those of CKD has attracted attention and urged researchers to discover their common therapeutic targets. Here, we summarize the current understanding of molecular aberrations underlying the lipid metabolism of NAFLD and CKD and clinical evidence that suggests the relevance of these pathways in humans. This review also highlights the orchestrated inter-organ cross-talk in lipid disorders, as well as therapeutic options and opportunities to counteract NAFLD and CKD.