Glycerol as a precursor for hepatic de novo glutathione synthesis in human liver

ZBED3 exacerbates hyperglycemia by promoting hepatic gluconeogenesis through CREB signaling

BACKGROUND

Elevated hepatic glucose production (HGP) is a prominent manifestation of impaired hepatic glucose metabolism in individuals with diabetes. Increased hepatic gluconeogenesis plays a pivotal role in the dysregulation of hepatic glucose metabolism and contributes significantly to fasting hyperglycemia in diabetes. Previous studies have identified zinc-finger BED domain-containing 3 (ZBED3) as a risk gene for type 2 diabetes (T2DM), and its single nucleotide polymorphism (SNPs) is closely associated with the fasting blood glucose level, suggesting a potential correlation between ZBED3 and the onset of diabetes. This study primarily explores the effect of ZBED3 on hepatic gluconeogenesis and analyzes the relevant signaling pathways that regulate hepatic gluconeogenesis.

METHODS

The expression level of ZBED3 was assessed in the liver of insulin-resistant (IR)-related disease. RNA-seq and bioinformatics analyses were employed to examine the ZBED3-related pathway that modulated HGP. To investigate the role of ZBED3 in hepatic gluconeogenesis, the expression of ZBED3 was manipulated by upregulation or silencing using adeno-associated virus (AAV) in mouse primary hepatocytes (MPHs) and HHL-5 cells. In vivo, hepatocyte-specific ZBED3 knockout mice were generated. Moreover, AAV8 was employed to achieve hepatocyte-specific overexpression and knockdown of ZBED3 in C57BL/6 and db/db mice. Immunoprecipitation and mass spectrometry (IP-MS) analyses were employed to identify proteins that interacted with ZBED3. Co-immunoprecipitation (co-IP), glutathione S-transferase (GST) - pulldown, and dual-luciferase reporter assays were conducted to further elucidate the underlying mechanism of ZBED3 in regulating hepatic gluconeogenesis.

RESULTS

The expression of ZBED3 in the liver of IR-related disease models was found to be increased. Under the stimulation of glucagon, ZBED3 promoted the expression of hepatic gluconeogenesis-related genes PGC1A, PCK1, G6PC, thereby increasing HGP. Consistently, the rate of hepatic gluconeogenesis was found to be elevated in mice with hepatocyte-specific overexpression of ZBED3 and decreased in those with ZBED3 knockout. Additionally, the knockdown of ZBED3 in the liver of db/db mice resulted in a reduction in hepatic gluconeogenesis. Moreover, the study revealed that ZBED3 facilitated the nuclear translocation of protein arginine methyltransferases 5 (PRMT5) to influence the regulation of PRMT5-mediated symmetrical dimethylation of arginine (s-DMA) of cyclic adenosine monophosphate (cAMP) response element binding protein (CREB), which in turn affects the phosphorylation of CREB and ultimately promotes HGP.

CONCLUSIONS

This study indicates that ZBED3 promotes hepatic gluconeogenesis and serves as a critical regulator of the progression of diabetes.

Supplementation with Chinese herbal preparations protect the gut-liver axis of Hu sheep, promotes gut-liver circulation, regulates intestinal flora and immunity

The gut-liver axis in ruminants can explain nutrient regulation, the gut-liver cycle, and immune function in ruminant biology through the gut microbe-gut metabolite-liver metabolite relationship. to investigate the effects of herbal feed additives on the gut-liver axis of Hu sheep. In this study, a broadly targeted UPLC-MS/MS metabolomics approach and 16s sequencing of gut microorganisms were used to detect, identify and quantify changes in ileal microorganisms, liver metabolites and ileal metabolites following the addition of Chinese herbal preparations. The addition of a 0.5% herbal feed additive increased ileal IgA, IgG and complement C3 levels. The addition of Chinese herbal preparations can increase the abundance of Firmicutes, Actinobacteriota, Bacteroidota, at the portal level of the ileum, increase the metabolism of organic matter and its derivatives, bile acids, amino acids and their metabolites, coenzymes, and vitamins in the liver and ileum, enhance nutrient absorption and waste metabolism, accelerate liver metabolism, promote gut-liver circulation, and improve ileal and liver immunity. This study provides a theoretical basis for understanding the effects of herbal feed additives on the gut-liver axis in ruminants.

Salvia elegans Vahl Counteracting Metabolic Syndrome and Depression in Mice on a High-Fat Diet

Salvia elegans Vahl is a plant commonly used in Mexico as a remedy for nervous disorders, inflammatory diseases, and "ringing in the ears"; the latter can be associated with arteriosclerotic conditions and arterial hypertension. Therefore, based on medicinal use, this work aimed to evaluate the hydroalcoholic extract (SeHA, 100 mg/kg) of this plant and two fractions, ethyl acetate (SeFAc, 50 mg/kg), and obtained from SeFAc fractionation denominated SeF3 (10 mg/kg), on several alterations derived from metabolic syndrome (MetS) derived from the ingestion of a high-calorie diet (high-fat diet), in ICR (Institute of Cancer Research) mice, leading to chronic inflammation that results in neurological damage such as depression. Therefore, several MetS-related parameters, such as forced swim tests, hypertension, serum corticosterone levels, glucose, triglycerides, cholesterol, adiposity index, and insulin resistance, will be evaluated. Additionally, tumor necrosis factor (TNF)-α, interleukin (IL)-1β, IL-6, and IL-10 levels were measured in kidneys, fat tissue, brains, and spleens. It was proven that all those S. elegans-derived treatments reversed the damage, showing antidepressant, antihypertensive, antihyperglycemic, and antidyslipidemic effects and decreased adiposity, insulin resistance, and serum corticosterone. They induced a modulatory response by modifying the levels of TNF-α, IL-1β, IL-6, and IL-10 in different organs. High-performance liquid chromatography (HPLC) analysis of the acetate of ethyl fraction from S. elegans (SeFAc) fraction revealed the presence of rosmarinic and caffeic acids as well as flavonoids, while the fraction from SeFAc called SeF3 Was identified by gas mass as methyl glucose, glycerol, and known sterols, among others. Thus, it was concluded that S. elegans protects against the harmful effects of MetS.

A robust ultra-performance liquid chromatography-tandem mass spectrometry method for simultaneous determination of 10 components in glutathione cycle

Glutathione (GSH) is an important antioxidant that is generated and degraded via the GSH cycle. Quantification of the main components in the GSH cycle is necessary to evaluate the process of GSH. In this study, a robust ultra-performance liquid chromatography-tandem mass spectrometry method for the simultaneous quantification of 10 components (GSH; γ-glutamylcysteine; cysteinyl-glycine; n-acetylcysteine; homocysteine; cysteine; cystine; methionine; glutamate; pyroglutamic acid) in GSH cycle was developed. The approach was optimized in terms of derivative, chromatographic, and spectrometric conditions as well as sample preparation. The unstable thiol groups of GSH, γ-glutamylcysteine, cysteinyl-glycine, n-acetylcysteine, cysteine, and homocysteine were derivatized by n-ethylmaleimide. The derivatized and underivatized analytes were separated on an amino column with gradient elution. The method was further validated in terms of selectivity (no interference), linearity (R2 > 0.99), precision (% relative standard deviation [RSD%] range from 0.57 to 10.33), accuracy (% relative error [RE%] range from -3.42 to 10.92), stability (RSD% < 5.68, RE% range from -2.54 to 4.40), recovery (RSD% range from 1.87 to 7.87) and matrix effect (RSD% < 5.42). The validated method was applied to compare the components in the GSH cycle between normal and oxidative stress cells, which would be helpful in clarifying the effect of oxidative stress on the GSH cycle.

Impacts of small-molecule STAT3 inhibitor SC-43 on toxicity, global proteomics and metabolomics of HepG2 cells

OBJECTIVE

In this study, we aimed to investigate the cytotoxicity and potential mechanisms of SC-43 by analyzing the global proteomics and metabolomics of HepG2 cells exposed to SC-43.

METHODS

The effect of SC-43 on cell viability was evaluated through CCK-8 assay. Proteomics and metabolomics studies were performed on HepG2 cells exposed to SC-43, and the functions of differentially expressed proteins and metabolites were categorized. Drug affinity responsive target stability (DARTS) was utilized to identify the potential binding proteins of SC-43 in HepG2 cells. Finally, based on the KEGG pathway database, the co-regulatory mechanism of SC-43 on HepG2 cells was elucidated by conducting a joint pathway analysis on the differentially expressed proteins and metabolites using the MetaboAnalyst 5.0 platform.

RESULTS

Liver cell viability is significantly impaired by continuous exposure to high concentrations of SC-43. Forty-eight dysregulated proteins (27 upregulated, 21 downregulated) were identified by proteomics analysis, and 184 dysregulated metabolites (65 upregulated, 119 downregulated) were determined by metabolomics in HepG2 cells exposed to SC-43 exposure compared with the control. A joint pathway analysis of proteomics and metabolomics data using the MetaboAnalyst 5.0 platform supported the close correlation between SC-43 toxicity toward HepG2 and the disturbances in pyrimidine metabolism, ferroptosis, mismatch repair, and ABC transporters. Specifically, SC-43 significantly affected the expression of several proteins and metabolites correlated with the above-mentioned functional pathways, such as uridine 5'-monophosphate, uridine, 3'-CMP, glutathione, γ-Glutamylcysteine, TF, MSH2, RPA1, RFC3, TAP1, and glycerol. The differential proteins suggested by the joint analysis were further selected for ELISA validation. The data showed that the RPA1 and TAP1 protein levels significantly increased in HepG2 cells exposed to SC-43 compared to the control group. The results of ELISA and joint analysis were basically in agreement. Notably, DARTS and biochemical analysis indicated that SART3 might be a potential target for SC-43 toxicity in HepG2 cells.

CONCLUSION

In summary, prolonged exposure of liver cells to high concentrations of SC-43 can result in significant damage. Based on a multi-omics analysis, we identified proteins and metabolites associated with SC-43-induced hepatocellular injury and clarified the underlying mechanism, providing new insights into the toxic mechanism of SC-43.

Glucagon-Like Peptide-1: New Regulator in Lipid Metabolism

Glucagon-like peptide-1 (GLP-1) is a 30-amino acid peptide hormone that is mainly expressed in the intestine and hypothalamus. In recent years, basic and clinical studies have shown that GLP-1 is closely related to lipid metabolism, and it can participate in lipid metabolism by inhibiting fat synthesis, promoting fat differentiation, enhancing cholesterol metabolism, and promoting adipose browning. GLP-1 plays a key role in the occurrence and development of metabolic diseases such as obesity, nonalcoholic fatty liver disease, and atherosclerosis by regulating lipid metabolism. It is expected to become a new target for the treatment of metabolic disorders. The effects of GLP-1 and dual agonists on lipid metabolism also provide a more complete treatment plan for metabolic diseases. This article reviews the recent research progress of GLP-1 in lipid metabolism.

A novel GK Ala469Val variant resulting in glycerol kinase deficiency with concurrent hepatoblastoma: A case report

Glycerol kinase deficiency (GKD) is a rare X-linked condition where glycerol cannot be phosphorylated to glycerol-3-phosphate, a key component of gluconeogenesis. Clinical presentation varies widely. We present a novel variant of the responsible GK in a patient with concurrent hepatoblastoma, whose course was complicated by hypoglycemia. Hepatoblastoma has not previously been described with GKD, highlighting the need for further research into GKD and its potential role in the pathogenesis of some forms of hepatoblastoma.

Laminaria japonica polysaccharide alleviates type 2 diabetes by regulating the microbiota-gut-liver axis: A multi-omics mechanistic analysis

The hypoglycemic effects of low-molecular-weight Laminaria japonica polysaccharide (LJO) were investigated in type 2 diabetes mellitus (T2DM) mice, focusing on its effect on the microbiome, metabolome, and transcriptome. The findings demonstrated that LJO significantly reduced fasting blood glucose levels, insulin levels, and inflammatory factors. Additionally, LJO induced changes in gut microbiota composition and increased the concentrations of cecal short-chain fatty acids. Analysis of transcriptomics and metabolomics data revealed that LJO primarily altered the endocrine and digestive systems, signal transduction, and lipid metabolism. It led to a decrease in palmitic acid levels and an increase in glutathione levels. Real-time quantitative polymerase chain reaction assay suggested that LJO upregulated Irs1 expression, consequently reducing insulin resistance. These findings strongly suggest that LJO holds promise in ameliorating T2DM and may serve as a potential dietary supplement for patients with T2DM.