Lipotoxic hepatocytes promote nonalcoholic fatty liver disease progression by delivering microRNA-9-5p and activating macrophages

Role and therapeutic perspectives of extracellular vesicles derived from liver and adipose tissue in metabolic dysfunction-associated steatotic liver disease

The global epidemic of metabolic diseases has led to the emergence of metabolic dysfunction-associated steatotic liver disease (MASLD) and metabolic dysfunction-associated steatohepatitis (MASH), which pose a significant threat to human health. Despite recent advances in research on the pathogenesis and treatment of MASLD/MASH, there is still a lack of more effective and targeted therapies. Extracellular vesicles (EVs) discovered in a wide range of tissues and body fluids encapsulate different activated biomolecules and mediate intercellular communication. Recent studies have shown that EVs derived from the liver and adipose tissue (AT) play vital roles in MASLD/MASH pathogenesis and therapeutics, depending on their sources and intervention types. Besides, adipose-derived stem cell (ADSC)-derived EVs appear to be more effective in mitigating MASLD/MASH. This review presents an overview of the definition, extraction strategies, and characterisation of EVs, with a particular focus on the biogenesis and release of exosomes. It also reviews the effects and potential molecular mechanisms of liver- and AT-derived EVs on MASLD/MASH, and emphasises the contribution and clinical therapeutic potential of ADSC-derived EVs. Furthermore, the future perspective of EV therapy in a clinical setting is discussed.

Epigenetic modifications in obesity-associated diseases

The global prevalence of obesity has reached epidemic levels, significantly elevating the susceptibility to various cardiometabolic conditions and certain types of cancer. In addition to causing metabolic abnormalities such as insulin resistance (IR), elevated blood glucose and lipids, and ectopic fat deposition, obesity can also damage pancreatic islet cells, endothelial cells, and cardiomyocytes through chronic inflammation, and even promote the development of a microenvironment conducive to cancer initiation. Improper dietary habits and lack of physical exercise are important behavioral factors that increase the risk of obesity, which can affect gene expression through epigenetic modifications. Epigenetic alterations can occur in early stage of obesity, some of which are reversible, while others persist over time and lead to obesity-related complications. Therefore, the dynamic adjustability of epigenetic modifications can be leveraged to reverse the development of obesity-associated diseases through behavioral interventions, drugs, and bariatric surgery. This review provides a comprehensive summary of the impact of epigenetic regulation on the initiation and development of obesity-associated cancers, type 2 diabetes, and cardiovascular diseases, establishing a theoretical basis for prevention, diagnosis, and treatment of these conditions.

Investigating the Role of Non-Coding RNA in Non-Alcoholic Fatty Liver Disease

Non-coding RNAs (ncRNAs) are RNA molecules that do not code for protein but play key roles in regulating cellular processes. NcRNAs globally affect gene expression in diverse physiological and pathological contexts. Functionally important ncRNAs act in chromatin modifications, in mRNA stabilization and translation, and in regulation of various signaling pathways. Non-alcoholic fatty liver disease (NAFLD) is a set of conditions caused by the accumulation of triacylglycerol in the liver. Studies of ncRNA in NAFLD are limited but have demonstrated that ncRNAs play a critical role in the pathogenesis of NAFLD. In this review, we summarize NAFLD's pathogenesis and clinical features, discuss current treatment options, and review the involvement of ncRNAs as regulatory molecules in NAFLD and its progression to non-alcoholic steatohepatitis (NASH). In addition, we highlight signaling pathways dysregulated in NAFLD and review their crosstalk with ncRNAs. Having a thorough understanding of the disease process's molecular mechanisms will facilitate development of highly effective diagnostic and therapeutic treatments. Such insights can also inform preventive strategies to minimize the disease's future development.

Hydroxysafflor yellow A inhibits the hyperactivation of rat platelets by regulating the miR-9a-5p/SRC axis

Pathological platelet activation plays a vital role in the prevalence of cardiovascular diseases. Hydroxysafflor yellow A (HSYA) has been shown to have significant anti-platelet aggregation and anti-activation effects, but its mechanism of action is unclear. Our study showed that HSYA inhibited the expression of platelet surface glycoproteins IIβ/III α (GPIIβ/III α) and thromboxane A2 (TXA2) during platelet activation and reduced platelet Ca2+ accumulation. HSYA significantly reduced the number of platelets and inhibited adrenaline-induced platelet hyperaggregation in rats. Transcriptomic analysis of platelets suggested that HSYA significantly suppressed SRC and MAPK3 (ERK1/2) gene expression. YEEI peptide, an SRC activator, could significantly reverse the inhibition of HSYA on the phosphorylation of SRC/PLCγ2/PKCδ/MEK/ERK1/2 pathway proteins and reverse the effect of HSYA on platelet activation-related markers GPIIβ/IIIα protein, TXA2 and cAMP. The SRC genes were further predicted by transcriptome analysis of HSYA-regulated miRNAs combined with bioinformatics techniques. The results suggested that HSYA could significantly upregulate the expression level of the miR-9a-5p gene and further confirmed that miR-9a-5p had a targeted regulatory relationship with SRC by dual-luciferase activity reporter and cell transfection experiments. The inhibitory effect of HSYA on the SRC/PLCγ2/PKCδ/MEK/ERK1/2 pathway was significantly reversed after platelets were transfected with the miR-9a inhibitor, while SRC siRNA attenuated the effect of the miR-9a inhibitor. SRC siRNA was able to attenuate the effect of the miR-9a inhibitor. In conclusion, this study suggests that HSYA can inhibit the activation of the SRC/PLCγ2/PKC δ/MEK/ERK1/2 axis by upregulating platelet miR-9a-5p, thereby reducing the activation of platelets and inhibiting platelet aggregation.

The emerging significance of mitochondrial targeted strategies in NAFLD treatment

Nonalcoholic fatty liver disease (NAFLD) is the most prevalent chronic liver disease worldwide, ranging from liver steatosis to nonalcoholic steatohepatitis, which ultimately progresses to fibrosis, cirrhosis, and hepatocellular carcinoma. Individuals with NAFLD have a higher risk of developing cardiovascular and extrahepatic cancers. Despite the great progress being made in understanding the pathogenesis and the introduction of new pharmacological targets for NAFLD, no drug or intervention has been accepted for its management. Recent evidence suggests that NAFLD may be a mitochondrial disease, as mitochondrial dysfunction is involved in the pathological processes that lead to NAFLD. In this review, we describe the recent advances in our understanding of the mechanisms associated with mitochondrial dysfunction in NAFLD progression. Moreover, we discuss recent advances in the efficacy of mitochondria-targeted compounds (e.g., Mito-Q, MitoVit-E, MitoTEMPO, SS-31, mitochondrial uncouplers, and mitochondrial pyruvate carrier inhibitors) for treating NAFLD. Furthermore, we present some medications currently being tested in clinical trials for NAFLD treatment, such as exercise, mesenchymal stem cells, bile acids and their analogs, and antidiabetic drugs, with a focus on their efficacy in improving mitochondrial function. Based on this evidence, further investigations into the development of mitochondria-based agents may provide new and promising alternatives for NAFLD management.

Controlled attenuation parameters to assess liver steatosis in obese patients with polycystic ovary syndrome

Objectives

This study was performed to investigate the changes and influencing factors of liver controlled attenuation parameter (CAP) in obese patients with polycystic ovary syndrome (PCOS), and to determine the prevalence and risk factors of nonalcoholic fatty liver disease (NAFLD) in PCOS patients with obesity.

Methods

Forty-one PCOS patients with obesity and twenty age- and body mass index (BMI)-matched control women without PCOS were enrolled in this study. General data, body composition, biochemical parameters, sex hormones, and liver CAP in the two groups were collected and compared. Liver CAP was measured using transient elastography.

Results

NAFLD was more common in the Obese PCOS group than in the control group (75.61% vs. 45.00%, P=0.018). Compared to the control group, the obese PCOS group showed apparent increases in alanine transaminase (ALT), aspartate transaminase (AST), CAP, triglyceride (TG), total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), totle testosterone (TT), free androgen index (FAI), fasting insulin (FIns), and homeostasis model assessment-insulin resistance (HOMA-IR), along with lower high-density lipoprotein cholesterol (HDL-C) and sex hormone binding globulin (SHBG) levels. In addition, as shown by Spearman analysis, liver CAP in PCOS patients with obesity had a positive correlation with ALT, AST, TG, TT, FAI, FIns, and HOMA-IR, and a negative correlation with SHBG. Logistic regression analysis showed that TG, TT, FIns, and HOMA-IR were risk factors for NAFLD, while TT was an independent risk factor for NAFLD in PCOS patients with obesity.

Conclusion

PCOS patients with obesity had a significantly higher prevalence of NAFLD. Furthermore, in PCOS patients with obesity, liver CAP was associated with disorders of lipid metabolism, insulin resistance, and hyperandrogenemia, with elevated testosterone levels being an independent risk factor for NAFLD in PCOS patients with obesity.

Therapeutic Effects of microRNAs on Nonalcoholic Fatty Liver Disease (NAFLD) and Nonalcoholic Steatohepatitis (NASH): A Systematic Review and Meta-Analysis

Nonalcoholic fatty liver disease (NAFLD) has emerged as a global health problem that affects people even at young ages due to unhealthy lifestyles. Without intervention, NAFLD will develop into nonalcoholic steatohepatitis (NASH) and eventually liver cirrhosis and hepatocellular carcinoma. Although lifestyle interventions are therapeutic, effective implementation remains challenging. In the efforts to establish effective treatment for NAFLD/NASH, microRNA (miRNA)-based therapies began to evolve in the last decade. Therefore, this systematic review aims to summarize current knowledge on the promising miRNA-based approaches in NAFLD/NASH therapies. A current systematic evaluation and a meta-analysis were conducted according to the PRISMA statement. In addition, a comprehensive exploration of PubMed, Cochrane, and Scopus databases was conducted to perform article searches. A total of 56 different miRNAs were reported as potential therapeutic agents in these studies. miRNA-34a antagonist/inhibitor was found to be the most studied variant (n = 7), and it significantly improved the hepatic total cholesterol, total triglyceride, Aspartate Aminotransferase (AST), and Alanine Transaminase (ALT) levels based on a meta-analysis. The biological processes mediated by these miRNAs involved hepatic fat accumulation, inflammation, and fibrosis. miRNAs have shown enormous therapeutic potential in the management of NAFLD/NASH, wherein miRNA-34a antagonist has been found to be an exceptional potential agent for the treatment of NAFLD/NASH.

Dihydromyricetin Inhibits M1 Macrophage Polarization in Atherosclerosis by Modulating miR-9-Mediated SIRT1/NF-κB Signaling Pathway

Dihydromyricetin (DMY), a natural flavonoid compound extracted from the stems and leaves of Ampelopsis grossedentata, has been found as a potential therapeutic chemical for treating atherosclerosis. This study explores the underlying mechanism of DMY repressing M1 macrophage polarization in atherosclerosis. We showed that DMY treatment markedly decreased M1 macrophage markers (e.g., Tnf-α and IL-1β) and p65-positive macrophage numbers in the vessel wall of Apoe-deficient (Apoe^-/-) mice. Overexpression of miR-9 or knockdown of SIRT1 in macrophages reversed the effect of DMY on M1 macrophage polarization. The data we presented in the study indicate that the miR-9-mediated SIRT1/NF-κB pathway plays a pivotal role in M1 macrophage polarization and is one of the molecular mechanisms underlying the anti-atherosclerosis effects of DMY. We provide new solid evidence that DMY may be explored as a potential therapeutic adjuvant for treating atherosclerosis.

Lactobacillus plantarum ZJUIDS14 alleviates non-alcoholic fatty liver disease in mice in association with modulation in the gut microbiota

This present study was designed to explore the protective role of Lactobacillus plantarum ZJUIDS14 against Non-alcoholic Fatty Liver Disease (NAFLD) in a high-fat-diet (HFD)-induced C57BL/6 mice model. The probiotic (10⁹ CFU/every other day) was administered by oral gavage for 12 weeks. We found that L. plantarum ZJUIDS14 intervention significantly alleviated HFD related hepatic steatosis, liver damage, insulin resistance, and increased hepatic expression of peroxisome proliferator activated receptor α (PPAR-α) while stimulating the activation of AMP-activated protein kinase (AMPK). Furthermore, L. plantarum ZJUIDS14 improved mitochondrial function as reflected by an increase in dynamin related protein 1 (DRP1) and a decrease of proteins associated with oxidative phosphorylation (OXPHOS) after the treatment. Additionally, mice from the L. plantarum ZJUIDS14 group had a restored intestinal flora and homeostasis involving Coprostanoligenes group, Ruminococcaceae UCG-014, Allobaculum, Ruminiclostridium 1, and Roseburia. Meanwhile, these five genera exhibited a significant (negative or positive) association with ileum inflammation mRNA levels and SCFA contents, by Spearman's correlation analysis. In general, our data demonstrated that L. plantarum ZJUIDS14 mitigates hepatic steatosis and liver damage induced by HFD. Specifically, they strengthened the integrity of the intestinal barrier, regulated gut microbiota, and improved mitochondrial function. Our data provide an experimental basis for L. plantarum ZJUIDS14 as a promising candidate to prevent NAFLD.

MicroRNA: role in macrophage polarization and the pathogenesis of the liver fibrosis

Macrophages, as central components of innate immunity, feature significant heterogeneity. Numerus studies have revealed the pivotal roles of macrophages in the pathogenesis of liver fibrosis induced by various factors. Hepatic macrophages function to trigger inflammation in response to injury. They induce liver fibrosis by activating hepatic stellate cells (HSCs), and then inflammation and fibrosis are alleviated by the degradation of the extracellular matrix and release of anti-inflammatory cytokines. MicroRNAs (miRNAs), a class of small non-coding endogenous RNA molecules that regulate gene expression through translation repression or mRNA degradation, have distinct roles in modulating macrophage activation, polarization, tissue infiltration, and inflammation regression. Considering the complex etiology and pathogenesis of liver diseases, the role and mechanism of miRNAs and macrophages in liver fibrosis need to be further clarified. We first summarized the origin, phenotypes and functions of hepatic macrophages, then clarified the role of miRNAs in the polarization of macrophages. Finally, we comprehensively discussed the role of miRNAs and macrophages in the pathogenesis of liver fibrotic disease. Understanding the mechanism of hepatic macrophage heterogeneity in various types of liver fibrosis and the role of miRNAs on macrophage polarization provides a useful reference for further research on miRNA-mediated macrophage polarization in liver fibrosis, and also contributes to the development of new therapies targeting miRNA and macrophage subsets for liver fibrosis.

A long non-coding RNA that harbors a SNP associated with type 2 diabetes regulates the expression of TGM2 gene in pancreatic beta cells

INTRODUCTION

Most of the disease-associated single nucleotide polymorphisms (SNPs) lie in non- coding regions of the human genome. Many of these variants have been predicted to impact the expression and function of long non-coding RNAs (lncRNA), but the contribution of these molecules to the development of complex diseases remains to be clarified.

METHODS

Here, we performed a genetic association study between a SNP located in a lncRNA known as LncTGM2 and the risk of developing type 2 diabetes (T2D), and analyzed its implication in disease pathogenesis at pancreatic beta cell level. Genetic association study was performed on human samples linking the rs2076380 polymorphism with T2D and glycemic traits. The pancreatic beta cell line EndoC-bH1 was employed for functional studies based on LncTGM2 silencing and overexpression experiments. Human pancreatic islets were used for eQTL analysis.

RESULTS

We have identified a genetic association between LncTGM2 and T2D risk. Functional characterization of the LncTGM2 revealed its implication in the transcriptional regulation of TGM2, coding for a transglutaminase. The T2Dassociated risk allele in LncTGM2 disrupts the secondary structure of this lncRNA, affecting its stability and the expression of TGM2 in pancreatic beta cells. Diminished LncTGM2 in human beta cells impairs glucose-stimulated insulin release.

CONCLUSIONS

These findings provide novel information on the molecular mechanisms by which T2D-associated SNPs in lncRNAs may contribute to disease, paving the way for the development of new therapies based on the modulation of lncRNAs.

NOD2-mediated HDAC6/NF-κb signalling pathway regulates ferroptosis induced by extracellular histone H3 in acute liver failure

Acute liver failure (ALF) is life-threatening and often associated with high mortality rates. The aim of the present study was to investigate whether extracellular histone H3 could induce ferroptosis in hepatic macrophages in ALF and explore its potential mechanism. RAW264.7 macrophages and C57BL/6 mice were used in this study. LPS, D-galactosamine (D-Gal), histone H3, histone H3 antibody, NOD2 agonist Muramyl Dipeptide (MDP) and HDAC6-siRNA were administered in this study. The key molecules of ferroptosis, NOD2, HDAC6 and the NF-κb pathway, were detected. In vitro, histone H3 was released into the extracellular environment from cell nucleus after LPS exposure. In addition, histone H3 could induce ferroptosis in RAW264.7 macrophages with increased level of Fe²⁺ and ROS and decreased levels of GPX4 and GSH. MDP further aggravated ferroptosis in RAW264.7 macrophages stimulated by histone H3, which was accompanied by elevated NOD2, HDAC6, p-P65 and IκBα. HDAC6-siRNA ameliorated ferroptosis in RAW264.7 macrophages induced by histone H3, which was accompanied by decreased levels of HDAC6, p-P65 and IκBα. However, HDAC6-siRNA did not alter NOD2 levels in RAW264.7 macrophages administered histone H3. In vivo, the levels of NOD2, HDAC6 the NF-κb pathway and ferroptosis were increased in ALF mice, which were downregulated by histone H3 antibody and upregulated by histone H3. Extracellular histone H3 could induce ferroptosis in hepatic macrophages in ALF by regulating theNOD2-mediated HDAC6/NF-κb signalling pathway.

miR-146a-5p promotes epithelium regeneration against LPS-induced inflammatory injury via targeting TAB1/TAK1/NF-κB signaling pathway

Intestinal inflammation often restricts the health and production of animals. MiR-146a has been proved to be an anti-inflammatory molecule in inflammatory disorders, but its role in the intestinal injury and regeneration remains unclear. The study aimed to explore the inflammatory response of intestinal epithelial cells (IECs) in intestinal tissue-specific miR-146a-5p knockout mouse models. We identified the role of miR-146a-5p in inhibiting inflammatory response and promoting proliferation under lipopolysaccharide (LPS) stimulation in vitro and vivo. LPS stimulation significantly increased the expression of TNF-α, IL6 and inhibited IPEC-J2 cell proliferation. Overexpression of miR-146a-5p can reverse the effect of LPS stimulation, and promote the proliferation of intestinal epithelial cells. In the LPS challenge experiment in intestine-specific miR-146a knock-out mice (CKO) and Floxp^+/+ mice (CON), CKO mice were more sensitive to LPS stimulation, with more weight loss and more severe intestinal morphological damage than CON mice. Also, miR-146a-5p regulated LPS-induced intestinal injury, inflammation by targeting TAB1. Taken together, miR-146a may function as an anti-inflammatory factor in IECs by targeting TAB1/TAK1-IKK-NF-κB signaling pathway. miR-146a-5p may represent a promising biomarker for inflammatory disorders, and may provide an effective therapeutic method to alleviate weaning stress in piglets and some experimental basis to improve the intestinal health of livestock.

CDC7 as a novel biomarker and druggable target in cancer

Due to the bottlenecks encountered in traditional treatment for tumor, more effective drug targets need to be developed. Cell division cycle 7 kinase plays an important role in DNA replication, DNA repair and recombination signaling pathways. In this review, we first describe recent studies on the role of CDC7 in DNA replication in normal human tissues, and then we integrate new evidence focusing on the important role of CDC7 in replication stress tolerance of tumor cells and its impact on the prognosis of clinical oncology patients. Finally, we comb through the CDC7 inhibitors identified in recent studies as a reference for further research in clinical practice.

Update on genetics and epigenetics in metabolic associated fatty liver disease

Nonalcoholic fatty liver disease (NAFLD) is becoming the most frequent chronic liver disease worldwide. Metabolic (dysfunction) associated fatty liver disease (MAFLD) is suggested to replace the nomenclature of NAFLD. For individuals with metabolic dysfunction, multiple NAFLD-related factors also contribute to the development and progression of MAFLD including genetics and epigenetics. The application of genome-wide association study (GWAS) and exome-wide association study (EWAS) uncovers single-nucleotide polymorphisms (SNPs) in MAFLD. In addition to the classic SNPs in PNPLA3, TM6SF2, and GCKR, some new SNPs have been found recently to contribute to the pathogenesis of liver steatosis. Epigenetic factors involving DNA methylation, histone modifications, non-coding RNAs regulations, and RNA methylation also play a critical role in MAFLD. DNA methylation is the most reported epigenetic modification. Developing a non-invasion biomarker to distinguish metabolic steatohepatitis (MASH) or liver fibrosis is ongoing. In this review, we summarized and discussed the latest progress in genetic and epigenetic factors of NAFLD/MAFLD, in order to provide potential clues for MAFLD treatment.