Improvement of MASLD and MASH by suppression of hepatic N-acetyltransferase 10.

OBJECTIVE: Metabolic dysfunction-associated steatotic liver disease (MASLD) and metabolic dysfunction-associated steatohepatitis (MASH) are characterized by excessive triglyceride accumulation in the liver. However, due to an incomplete understanding of its pathogenesis, more efforts are needed to identify specific and effective treatments. N4-acetylcytidine (ac4C) is a newly discovered RNA modification to regulate mRNA. N-acetyltransferase 10 (NAT10) has not been fully explored in MASLD and MASH. METHODS: The clinical relevance of NAT10 was evaluated based on its expression in various mouse and human models of MASLD and MASH. Acetylated RNA immunoprecipitation sequencing and mRNA stability assays were used to explore the role of NAT10 in regulating ac4C modification and expression of target genes. Genetically engineered mice were employed to investigate the role of NAT10 in MASLD and MASH progression. RESULTS: Hepatic NAT10 expression was significantly increased in multiple mice and humans of MASLD and MASH. Genetic knockout of NAT10 protected mice from diet-induced hepatic steatosis and steatohepatitis, whereas overexpression of NAT10 exacerbated high-fat-diet-induced liver steatosis. Mechanistically, NAT10 binds to Srebp-1c mRNA, promoting its stability and expression, thereby upregulating lipogenic enzymes. Treatment with Remodelin, a NAT10-specific inhibitor, effectively ameliorates liver steatosis and dyslipidemia in a preclinical mouse model. CONCLUSIONS: Our findings indicate that NAT10 could regulate lipid metabolism in MASLD and MASH by stabilizing Srebp-1c mRNA and upregulating lipogenic enzymes. This study highlights the role of NAT10 and RNA acetylation in the pathogenesis of MASLD and MASH. Thus, our findings suggest a promising new therapeutic approach, such as the use of NAT10 inhibitor, for treating metabolic liver disease.

Amelioration of nonalcoholic fatty liver disease by inhibiting the deubiquitylating enzyme RPN11.

Nonalcoholic fatty liver disease (NAFLD), including its more severe manifestation nonalcoholic steatohepatitis (NASH), is a global public health challenge. Here, we explore the role of deubiquitinating enzyme RPN11 in NAFLD and NASH. Hepatocyte-specific RPN11 knockout mice are protected from diet-induced liver steatosis, insulin resistance, and steatohepatitis. Mechanistically, RPN11 deubiquitinates and stabilizes METTL3 to enhance the m6A modification and expression of acyl-coenzyme A (CoA) synthetase short-chain family member 3 (ACSS3), which generates propionyl-CoA to upregulate lipid metabolism genes via histone propionylation. The RPN11-METTL3-ACSS3-histone propionylation pathway is activated in the livers of patients with NAFLD. Pharmacological inhibition of RPN11 by Capzimin ameliorated NAFLD, NASH, and related metabolic disorders in mice and reduced lipid contents in human hepatocytes cultured in 2D and 3D. These results demonstrate that RPN11 is a novel regulator of NAFLD/NASH and that suppressing RPN11 has therapeutic potential for the treatment.

Transcription factor DgMYB recruits H3K4me3 methylase to DgPEROXIDASE to enhance chrysanthemum cold tolerance.

Cold affects the growth and development of plants. MYB transcription factors and histone H3K4me3 transferase ARABIDOPSIS TRITHORAXs (ATXs) play important regulatory functions in the process of plant resistance to low-temperature stress. In this study, DgMYB expression was responsive to low temperature, and overexpression of DgMYB led to increased tolerance, whereas the dgmyb mutant resulted in decreased tolerance of Chrysanthemum morifolium (Dendranthema grandiflorum var. Jinba) to cold stresses. Interestingly, we found that only peroxidase (POD) activity differed substantially between wild type (WT), overexpression lines, and the mutant line. A DgATX H3K4me3 methylase that interacts with DgMYB was isolated by further experiments. DgATX expression was also responsive to low temperature. Overexpression of DgATX led to increased tolerance, whereas the dgatx mutant resulted in decreased tolerance of chrysanthemum to cold stresses. Moreover, the dgmyb, dgatx, and dgmyb dgatx double mutants all led to reduced H3K4me3 levels at DgPOD, thus reducing DgPOD expression. Together, our results show that DgMYB interacts with DgATX, allowing DgATX to specifically target DgPOD, altering H3K4me3 levels, increasing DgPOD expression, and thereby reducing the accumulation of reactive oxygen species (ROS) in chrysanthemum.

Orosomucoid 2 maintains hepatic lipid homeostasis through suppression of de novo lipogenesis.

Non-alcoholic fatty liver disease (NAFLD) is caused by imbalance in lipid metabolism. In this study, we show that the hepatokine orosomucoid (ORM) 2 is a key regulator of de novo lipogenesis in the liver. Hepatic and plasma ORM2 levels are markedly decreased in obese murine models and patients with NAFLD. Through multiple loss- and gain-of function studies, we demonstrate that ORM2 is essential to maintain hepatic and systemic lipid homeostasis. At the mechanistic level, ORM2 binds to inositol 1, 4, 5-trisphosphate receptor type 2 to activate AMP-activated protein kinase signaling, thereby inhibiting sterol regulatory element binding protein 1c-mediated lipogenic gene program. Notably, intraperitoneal injections of recombinant ORM2 protein or stabilized ORM2-FC fusion protein markedly improved liver steatosis, steatohepatitis and atherosclerosis in preclinical mouse models, without adverse effects on body weight or food intake. Thus, these findings suggest that ORM2 may serve as a potential target for therapeutic intervention in NAFLD, non-alcoholic steatohepatitis and related lipid disorders.

DgbZIP3 interacts with DgbZIP2 to increase the expression of DgPOD for cold stress tolerance in chrysanthemum.

The bZIP transcription factor plays a very important role in abiotic stresses, e.g. drought, salt, and low-temperature stress, but the mechanism of action at low temperature is still unclear. In this study, overexpression of DgbZIP3 led to increased tolerance of chrysanthemum (Chrysanthemum morifolium Ramat.) to cold stress, whereas antisense suppression of DgbZIP3 resulted in decreased tolerance. Electrophoretic mobility shift assay (EMSA), chromatin immunoprecipitation (ChIP), luciferase complementary imaging analysis (LCI), and dual-luciferase reporter gene detection (DLA) experiments indicated that DgbZIP3 directly bound to the promoter of DgPOD and activated its expression. DgbZIP2 was identified as a DgbZIP3-interacting protein using yeast two-hybrid, co-immunoprecipitation, LCI, and bimolecular fluorescence complementation assays. Overexpression of DgbZIP2 led to increased tolerance of chrysanthemum to cold stress, whereas antisense suppression of DgbZIP2 resulted in decreased tolerance. A ChIP-qPCR experiment showed that DgbZIP2 was highly enriched in the promoter of DgPOD, while DLA, EMSA, and LCI experiments further showed that DgbZIP2 could not directly regulate the expression of DgPOD. The above results show that DgbZIP3 interacts with DgbZIP2 to regulate the expression of DgPOD to promote an increase in peroxidase activity, thereby regulating the balance of reactive oxygen species and improving the tolerance of chrysanthemum to low-temperature stress.

Lysine decrotonylation of glutathione peroxidase at lysine 220 site increases glutathione peroxidase activity to resist cold stress in chrysanthemum.

Lysine crotonylation is a protein post-translational modification that has been newly discovered in recent years. There are few studies on the lysine crotonylation of proteins in plants, and their functions in response to cold stress are still unclear. In this study, the chrysanthemum (Chrysanthemum morifolium Ramat.) glutathione peroxidase (GPX) gene was selected and named DgGPX1, and was found to be responsive to low temperature. Overexpression of DgGPX1 improved the cold resistance of transgenic chrysanthemum by increasing GPX activity to reduce the accumulation of reactive oxygen species (ROS) under low-temperature conditions. Furthermore, the level of DgGPX1 lysine crotonylation at lysine (K) 220 decreased under low temperature in chrysanthemum. Lysine decrotonylation of DgGPX1 at K220 further increased GPX activity to reduce ROS accumulation under cold stress, and thereby enhanced the cold resistance of chrysanthemum. The above results show that lysine decrotonylation of DgGPX1 at K220 increases GPX activity to resist cold stress in chrysanthemum.

DgMYB2 improves cold resistance in chrysanthemum by directly targeting DgGPX1.

MYB transcription factors play important roles in plant responses to cold stress, but the associated underlying mechanisms remain unclear. In this study, a cold-induced MYB transcription factor, DgMYB2, was isolated from chrysanthemum (Chrysanthemum morifolium Ramat). DgMYB2 was localized to the nucleus and exhibited transactivational activity. Overexpression of DgMYB2 improved cold tolerance in chrysanthemum, while cold tolerance in the antisense suppression lines decreased compared to that of the wild type. Additionally, electrophoretic mobility shift assays, chromatin immunoprecipitation, luciferase complementary imaging analysis, and dual-luciferase reporter gene detection experiments confirmed that DgMYB2 directly targets DgGPX1 and increases the activity of glutathione peroxidase to reduce the accumulation of reactive oxygen species, thereby improving cold resistance in chrysanthemum.

Analysis of N6-Methyladenosine Methylation Modification in Fructose-Induced Non-Alcoholic Fatty Liver Disease.

Improvements in living standards have led to non-alcoholic fatty liver disease (NAFLD), one of the most common chronic liver diseases worldwide. Recent studies have shown that N6-methyladenosine (m6A), a type of RNA modification, is strongly associated with many important biological processes. However, the relationship between m6A methylation modifications and NAFLD remains poorly understood. In the present study, through methylated RNA immunoprecipitation sequencing and RNA transcriptome sequencing in high fructose diet-induced NAFLD mice, we found that hypermethylation-encoding genes were mainly enriched in lipid metabolism processes. We identified 266 overlapping and differentially expressed genes (DEGs) that changed at both the mRNA expression level and m6A modification level. Among them, 193 genes displayed increased expression and m6A modification, indicating that m6A RNA modifications tend to be positively correlated with NAFLD. We further compared the high fructose diet-induced NAFLD mouse model with leptin receptor-deficient mice and found that DEGs enriched in the lipid metabolism pathway were up-regulated in both groups. In contrast, DEGs associated with the immune inflammatory response were up-regulated in the high fructose diet group, but down-regulated in leptin receptor-deficient mice. Taken together, our results demonstrate that m6A methylation modifications may play an important role in the development of NAFLD.

High-Fiber Diet or Combined With Acarbose Alleviates Heterogeneous Phenotypes of Polycystic Ovary Syndrome by Regulating Gut Microbiota.

Objective: Gut microbial dysbiosis is associated with high heterogeneity of polycystic ovary syndrome (PCOS); however, studies about gut microbiota targeted clinical intervention in PCOS are limited. Our study aimed to evaluate the effects of high-fiber diet or combined with acarbose on the clinical phenotypes of PCOS, focusing on the possible influence of gut microbiota in this process. Methods: Twenty-five patients with PCOS were recruited and randomly divided into two groups, W group (n = 14) received the WTP diet (a high-fiber diet composed of whole grains, traditional Chinese medicinal foods, and prebiotics), and A group (n = 11) received the WTP diet combined with acarbose. The follow-up time was 12 weeks. The sex hormonal and glycolipid metabolic parameters, inflammatory factors, brain-gut peptides, and alteration of gut microbiota were evaluated. Results: The PCOS clinical phenotypes, inflammatory state, and brain-gut peptides secretion were all alleviated in both groups, while the hyperandrogenism, insulin resistance, and brain-gut peptides secretion were better improved in the A group. Alpha and beta diversities were altered more significantly in the A group. Amplicon sequence variants (ASVs) were clustered into 14 co-abundant groups (CAGs) as potential functional groups that may respond to the intervention. The CAGs predominantly comprised of Bifidobacterium and Lactobacillus were more enriched, while the CAGs predominantly comprised of Bacteroides vulgatus, Alistipes, Blautia, Lachnospira, and Roseburia were more inhibited in the A group than in W group. Moreover, the CAGs enriched in the A group had a stronger negative correlation with the luteinizing hormone (LH)/follicle-stimulating hormone (FSH) ratio, testosterone, homeostasis model assessment-insulin resistance (HOMA-IR), α-1-acid glycoprotein (α-AGP), and leptin, and positive correlation with adiponectin and spexin, while the CAGs inhibited showed an opposite trend. Conclusions: High-fiber diet could alleviate the chronic metabolic inflammation, reproductive function, and brain-gut peptides secretion of patients with PCOS, and high-fiber diet combined with acarbose could better improve the PCOS clinical phenotypes. The remodeling of gut microbiota by our intervention may play an important role in these improvements. Clinical Trial Registration: http://www.chictr.org.cn/showproj.aspx?proj=4500, ChiCTR-TRC-14005075.

Lysine crotonylation of DgTIL1 at K72 modulates cold tolerance by enhancing DgnsLTP stability in chrysanthemum.

Lysine crotonylation of proteins is a recently identified post-translational modification (PTM) in plants. However, the function of lysine-crotonylated proteins in response to abiotic stress in plants has not been reported. In this study, we identified a temperature-induced lipocalin-1-like gene (DgTIL1) from chrysanthemum and showed that it was notably induced in response to cold stress. Overexpression of DgTIL1 enhanced cold tolerance in transgenic chrysanthemum. Ubiquitin membrane yeast two-hybrid (MYTH) system and bimolecular fluorescence complementation (BIFC) assays showed that DgTIL1 interacts with a nonspecific lipid transfer protein (DgnsLTP), which can promote peroxidase (POD) gene expression and POD activity to reduce the accumulation of reactive oxygen species (ROS) and improve resistance to cold stress in DgnsLTP transgenic chrysanthemum. In addition, we found that DgTIL1 was lysine crotonylated at K72 in response to low temperature in chrysanthemum. Moreover, lysine crotonylation of DgTIL1 prevented DgnsLTP protein degradation in tobacco and chrysanthemum. Inhibition of DgnsLTP degradation by lysine crotonylation of DgTIL1 further enhanced POD expression and POD activity, reduced the accumulation of ROS under cold stress in DgTIL1 transgenic chrysanthemum, thus promoting the cold resistance of chrysanthemum.

Liraglutide Improves Non-Alcoholic Fatty Liver Disease In Diabetic Mice By Modulating Inflammatory Signaling Pathways.

BACKGROUND: Many chronic metabolic diseases, such as obesity and type 2 diabetes (T2DM), are closely related to a chronic low-grade inflammatory state in tissues. The high prevalence of non-alcoholic fatty liver disease (NAFLD) in patients with T2DM is related to the role of inflammation in the disease. In this study, we investigated the role of liraglutide in improving lipid metabolism disorders and preventing their progression to NAFLD by modulating inflammatory signaling pathways, thereby providing new treatment options for NAFLD. METHODS: We designed a 2×2 factorial analysis experiment. A mouse model of NAFLD with T2DM was established by feeding the animals a high-fat diet (HFD). The NAFLD mice with HFD-induced diabetes were treated with liraglutide for 10 weeks. Hematoxylin and eosin staining, Oil Red O staining and electron microscopy were used to observe the accumulation of triglycerides in the liver. RT-PCR and Western blotting were used to analyze the expression of α-SMA, IL-1ß, TNF-α, NF-κB and the NF-κB inhibitory protein IκB in the liver at the gene and protein levels, respectively. RESULTS: Liraglutide reduced the body weight and fasting blood glucose levels of HFD-fed mice. The expression of α-SMA, IL-1ß, TNF-α, and NF-κB in the liver of HFD-fed mice was increased at the mRNA and protein levels, but liraglutide treatment decreased the expression of these molecules. The expression of IκB in the liver decreased at the mRNA and protein levels but was upregulated after liraglutide treatment. CONCLUSION: Based on the current findings, liraglutide can significantly improve hepatic steatosis, primarily by downregulating the expression of inflammatory signaling mediators in the TNF-α pathway.

KIF20A promotes cellular malignant behavior and enhances resistance to chemotherapy in colorectal cancer through regulation of the JAK/STAT3 signaling pathway.

BACKGROUND/AIMS: Kinesin family member 20A (KIF20A) is upregulated in multiple cancers and plays important roles in promoting malignant behavior, whereas its exact role in CRC remains unknown. RESULTS: Both genomic and protein expression levels showed that KIF20A was upregulated in CRC. Further functional analyses revealed that KIF20A had a crucial role in improving cell proliferation and resistance to chemotherapy in CRC. Finally, we provided distinct mechanistic evidence that KIF20A achieved all of its pathological functions in CRC by activating the JAK/STAT3 pathway. CONCLUSION: Our results suggested that KIF20A regulated a set of malignant characteristics in CRC by activating the JAK/STAT3 pathway. Our findings indicate a new direction for the development of more effective therapeutic treatments for CRC. METHODS: Three Gene Expression Omnibus datasets and The Cancer Genome Atlas datasets were used to investigate the expression level of KIF20A in CRC. Further experiments included immunohistochemical staining, western blot analysis, qRT-PCR, gene silencing, and a cell-injected xenograft mouse model to investigate the interaction between KIF20A and the JAK/STAT3 signaling pathway in both patient-derived specimens and CRC cell lines.

Liraglutide ameliorates nonalcoholic fatty liver disease in diabetic mice via the IRS2/PI3K/Akt signaling pathway.

Purpose: High prevalence of nonalcoholic fatty liver disease (NAFLD) among patients with type 2 diabetes has implicated the role of hepatic insulin resistance (IR) in the diseases. To better understand the underlying mechanism, we have evaluated the pathophysiological effects of Liraglutide on NAFLD via the insulin signaling pathway. Patients and methods: A 2×2 factorial experiment was designed. High-fat diet (HFD)-induced NAFLD mice with diabetes were treated with Liraglutide for 10 weeks, while the control mice were saline-treated. Hepatic expressions of InsR, IGF-1R, IRS2, PI3K and Akt at mRNA and protein levels were analyzed with RT-PCR and Western blotting. Hematoxylin and eosin staining, Oil Red O staining and electron microscopy were used to visualize triglyceride accumulation in liver. Results: Liraglutide significantly decreased body weight, fasting blood glucose levels and HOMA-IR scores in HFD mice. Compared with the control mice fed with chow diet, hepatic expressions of InsR, IRS2, PI3K and Akt at both mRNA and protein levels in HFD mice were significantly reduced, but upregulated after Liraglutide treatment. Furthermore, Liraglutide treatment was found to improve hepatic steatosis. Conclusion: The current study thereby provides evidence that Liraglutide ameliorates NAFLD and improves hepatic steatosis mainly by upregulation of the IRS2/PI3K/Akt signaling mediators.

Prevalence of abnormal glucose homeostasis in Chinese patients with non-transfusion-dependent thalassemia.

Purpose: To determine the prevalence and underlying pathology of abnormal glucose homeostasis in Chinese patients with non-transfusion-dependent thalassemia (NTDT). Patients and methods: In this study, we enrolled 211 patients aged 4-63 years with NTDT, including 79 ß thalassemia intermedia patients, 114 Hb H disease patients and 18 Hb E/ß thalassemia patients. All had oral glucose tolerance test, serum ferritin (SF), homeostasis model assessment (HOMA) and liver iron concentration (LIC) measurement. One hundred and twenty healthy age-matched controls were also used for the comparative purpose. Iron load was assessed by using SF and hepatic load by LIC using validated MRI techniques. Results: The 211 patients were divided into three groups according to their fasting and 2 hrs postprandial blood glucose levels: hypoglycemic, normal glucose tolerance (NGT) and hyperglycemic groups. In this study, 149 patients had NGT, 33 had hypoglycemia, 4 had diabetes and 25 had impaired glucose tolerance (IGT). None had impaired fasting glucose. There was a significant correlation between 2 hrs postprandial blood glucose levels and age, PINS120, HOMA-IR, alanine aminotransferase and LIC (P<0.05). Risk factors for IGT in NTDT patients were older age (≥24 years) and SF concentration of ≥2,500 ng/mL. Conclusion: Age ≥24 years and SF ≥2,500 ng/mL of NTDT patients were at a greater risk for impaired glucose tolerance.

Integrated Bioinformatics Analysis Identifies Hub Genes Associated with the Pathogenesis and Prognosis of Esophageal Squamous Cell Carcinoma.

Esophageal squamous cell carcinoma (ESCC) accounts for over 90% of all esophageal tumors. However, the molecular mechanism underlying ESCC development and prognosis remains unclear, and there are still no effective molecular biomarkers for diagnosing or predicting the clinical outcome of patients with ESCC. Here, using bioinformatics analyses, we attempted to identify potential biomarkers and therapeutic targets for ESCC. Differentially expressed genes (DEGs) between ESCC and normal esophageal tissue samples were obtained through comprehensive analysis of three publicly available gene expression profile datasets from the Gene Expression Omnibus database. The biological roles of the DEGs were identified by Gene Ontology (GO) annotation and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis. Moreover, the Cytoscape 3.7.1 platform and subsidiary tools such as Molecular Complex Detection (MCODE) and CytoHubba were used to visualize the protein-protein interaction (PPI) network of the DEGs and identify hub genes. A total of 345 DEGs were identified between normal esophageal and ESCC samples, which were enriched in the KEGG pathways of the cell cycle, endocytosis, pancreatic secretion, and fatty acid metabolism. Two of the highest scoring models were selected from the PPI network using Molecular Complex Detection. Moreover, CytoHubba revealed 21 hub genes with a valuable influence on the progression of ESCC in these patients. Among these, the high expression levels of five genes-SPP1, SPARC, BGN, POSTN, and COL1A2-were associated with poor disease-free survival of ESCC patients, as indicated by survival analysis. Taken together, we identified that elevated expression of five hub genes, including SPP1, is associated with poor prognosis in ESCC patients, which may serve as potential prognostic biomarkers or therapeutic target for ESCC.