TET2 regulation of alcoholic fatty liver via Srebp1 mRNA in paraspeckles.

Epigenetic modifications have emerged as key regulators of metabolism-related complex diseases including the alcoholic fatty liver disease (AFLD) prevalent chronic liver disorder with significant economic implications. Building upon previous research that emphasizes ten-eleven translocation (TET) proteins' involvement in adipocyte insulin sensitization and fatty acid oxidation, we explored the role of TET2 protein in AFLD pathogenesis which catalyzes 5-methylcytosine into 5-hydroxymethylcytosine in DNA/RNA. Our findings revealed that TET2 deficiency exacerbates AFLD progression. And TET2 influenced the expression and activity of sterol regulatory element binding protein 1 (SREBP1), a key regulator of hepatic lipid synthesis, by modulating Srebp1 mRNA retention. Employing RIP-qPCR and bisulfite sequencing techniques, we provided evidence of TET2-mediated epigenetic modifications on Srebp1 mRNA, thereby affecting lipid metabolism. Through elucidating the role of methylation in RNA nuclear retention via paraspeckles, our study enhances understanding of AFLD pathogenesis from an epigenetic perspective, paving the way for identifying potential therapeutic targets.

Evaluation of the Protective Bioactivity and Molecular Mechanism Verification of Lactoferrin in an Alzheimer's Mouse Model with Ulcerative Enteritis.

The development of new drug therapies for Alzheimer's disease (AD) is an important research topic today, but the pathogenesis of AD has not been thoroughly studied, and there are still several shortcomings in existing drug therapies. Therefore, this study aims to explore the molecular mechanism of lactoferrin in the treatments of AD and ulcerative colitis (UC) which are susceptible to AD, starting from the principle of "one drug, two diseases, and the same treatment." This study used pathological staining and specific indicators staining to preliminarily evaluate the interventions of lactoferrin on UC injury and AD progression. And 16s RNA full-length sequencing was used to investigate the effect of lactoferrin on the abundance of intestinal microbiota in AD mice. Then, intestinal tissue and brain tissue metabolomics analysis were used to screen specific metabolic pathways and preliminarily verify the metabolic mechanism of lactoferrin in alleviating 2 diseases by regulating certain specific metabolites. Moreover, lactoferrin significantly changed the types and abundance of gut microbiota in AD mice complicated by UC. To conclude, this study proved the clinical phenomenon of AD susceptibility to UC, and verified the therapeutic effect of lactoferrin on 2 diseases. More importantly, we revealed the possible molecular mechanism of LF, not only does it enrich the cognitive level of lactoferrin in alleviating AD by regulating the gut microbiota through the brain gut axis from the perspective of the theory of "food nutrition promoting human health," but it also provides a practical basis for the subsequent research and development of lactoferrin and drug validation from the perspective of "drug food homology."

Adipose improves muscular atrophy caused by Sirtuin1 deficiency by promoting mitochondria synthesis.

Muscular dysplasia is a common muscle disease, but its pathological mechanism is still unclear. Adipose is originally identified as a highly conservative and widely expressed anti-obesity gene, and our previous study has reported that Adipose is also a positive regulator of myogenesis. Considering the vital role of during muscle development, this study was to demonstrate a potential relationship between Sirtuin1 and Adipose and clarified the mechanism by which Adipose regulated muscle development. Our results showed that the muscle fiber cross-sectional area and myosin heavy chain protein level were significantly reduced in Sirtuin1+/- mice. Moreover, the longitudinal section of muscle fibers was obviously irregular. Sirtuin1 knockdown significantly reduced the expression levels of Adipose and its upstream transcriptional regulator Kruppel like factor 15 and notably inhibited the AMP-activated protein kinase α-peroxisome proliferator-activated receptor gamma coactivator 1α signaling pathway in skeletal muscle. However, Adipose over-expression activated this signaling pathway and promoted mitochondrial biosynthesis in C2C12 myoblasts. Adipose over-expression also enhanced glucose absorption of C2C12 cells, suggesting the increased needs for cells for metabolic substrates. In C2C12 cells with hydrogen peroxide treatment, Adipose over-expression repressed hydrogen peroxide-elicited apoptosis and mitochondrial loss, while Sirtuin1-specific inhibitor dramatically weakened these roles of Adipose. Taken together, our findings reveal that Adipose rescues the adverse effects of Sirtuin1 deficiency or hydrogen peroxide on muscle development by activating the AMP-activated protein kinase α- peroxisome proliferator-activated receptor gamma coactivator 1α pathway to promote mitochondria synthesis, which provides theoretical basis for developing new therapeutic targets against some muscle diseases.

sSTEAP4 regulates cellular homeostasis and improves high-fat-diet-caused oxidative stress in hepatocytes.

AIM: Nonalcoholic fatty liver disease (NAFLD) has become a global epidemic, but its pathogenesis is unclear. STEAP4, a member of six transmembrane protein family, integrates inflammatory and metabolic responses. Our present aim is to explore the roles of STEAP4 in maintaining cellular homeostasis and improving high-fat-diet (HFD)-caused oxidative stress in hepatocytes. MAIN METHODS: NAFLD model was established by HFD-feeding mice. The effects of over-nutrition on liver were detected by serum biochemical analysis and bulk RNA-seq. The levels of gene expression were measured by QPCR and Western Blot. Immunofluorescent staining was applied to determine the localization of STEAP4. AMPK agonist was employed to investigate the link between STEAP4 and AMPK pathway. KEY FINDINGS: Sus scrofa STEAP4 (sSTEAP4) relieved oxidative stress and rescued the viability of hepatocytes. sSTEAP4 increased AKT phosphorylation and SOD2 level in hepatocytes, whether or not treated with H2O2, suggesting sSTEAP4 has regulatory effects on insulin signaling and antioxidant pathways. However, sSTEAP4 inhibited AMPK phosphorylation and Beclin1/LC3 expression under H2O2-deficiency situation, but the results were conversed with H2O2 stimulation. The cellular ER stress was aggravated with the increased energy during oxidative stress, indicating that sSTEAP4 might regulate the energetic communication between ER and mitochondria by intervening mitochondrial energy production. In addition, sSTEAP4 was demonstrated to localize in the membranes of plasma and ER in HepG2 hepatocytes. SIGNIFICANCE: Our results reveal that sSTEAP4 based on the needs of cell itself to improve hepatic oxidative stress and HFD-caused NAFLD, which might provide a new therapeutic scheme for NAFLD.

PPARγ enhanced Adiponectin polymerization and trafficking by promoting RUVBL2 expression during adipogenic differentiation.

Adipocyte differentiation is an essential part of adipose tissue development, and is closely related to obesity and obesity-related diseases. In this study, we found that the expression of PPARγ, RUVBL2 and Adiponectin were concurrently obviously increased in the 5th-7th day of 3T3-L1 cell differentiation. PPARγ overexpression or the PPARγ activator facilitated Adiponectin trafficking and secretion and upregulated RUVBL2 expression as well as AS160 phosphorylation during adipogenic differentiation of 3T3-L1 cells. Consistently RUVBL2 overexpression also enhanced the polymerization and secretion of Adiponectin, in contrast, RUVBL2 knockdown reduced Adiponectin secretion. Further, PPARγ significantly enhanced RUVBL2 promoter activity and transcription. The progressive deletions and mutations of RUVBL2 promoter for PPARγ binding sites suggested that the PPARγ binding motif situated at -804/-781 bp is an essential component required for RUVBL2 promoter activity. Chromatin immunoprecipitation (ChIP) assays determined that PPARγ can directly interact with the RUVBL2 promoter DNA. Taken together, these data suggest that PPARγ promotes the expression, polymerization and secretion of Adiponectin by activating RUVBL2 transcriptionally, which accelerates 3T3-L1 cell differentiation.

Sirt1 Promotes the Restoration of Hepatic Progenitor Cell (HPC)-Mediated Liver Fatty Injury in NAFLD Through Activating the Wnt/ß-Catenin Signal Pathway.

Non-alcoholic fatty liver disease (NAFLD) has developed into the world's largest chronic epidemic. In NAFLD, hepatic steatosis causes hepatocytes dysfunction and even apoptosis. The liver has a strong restoration or regeneration ability after an injury, however, it is unclear through which pattern fatty liver injury in NAFLD is repaired and what the repair mechanism is. Here, we found that in the high-fat diet (HFD)-induced NAFLD mice model, fatty liver injury caused the significant ductular reaction (DR), which is a marker to promote the repair of liver injury. SOX9+ and HNF4α+ biphenotype also suggested that hepatic progenitor cells (HPCs) were activated by fatty liver injury in the HFD-elicited NAFLD mice model. Concurrently, fatty liver injury also activated the Wnt/ß-catenin signal pathway, which is a necessary process for HPC differentiation into mature hepatocytes. However, Sirt1 knockdown weakened HPC activation and Wnt/ß-catenin signal in Sirt1+/- mice with HFD feeding. In rat-derived WB-F344 hepatic stem cell line, Sirt1 overexpression (OE) or Sirt1 activator-Resveratrol promoted HPC differentiation via activating Wnt/ß-catenin signal pathway. Glycogen PAS staining demonstrated that Sirt1 OE promoted WB-F344 cells to differentiate into mature hepatocytes with glycogen synthesis ability, while Sirt1 inhibitor EX527 or Wnt/ß-catenin pathway inhibitor HF535 decreased glycogen positive cells. Together, our data suggested that Sirt1 plays a vital role in activating HPCs to repair fatty liver injury or promote liver regeneration through the Wnt/ß-catenin signal pathway in NAFLD, which might provide a new strategy for fatty liver injury or NAFLD therapy.

KLF15-activating Twist2 ameliorated hepatic steatosis by inhibiting inflammation and improving mitochondrial dysfunction via NF-κB-FGF21 or SREBP1c-FGF21 pathway.

Twist-related protein 2 (TWIST2) is identified as a basic helix-loop-helix (b-HLH) transcription repressor by dimerizing with other b-HLH proteins. The significance of TWIST2 has been emphasized in various tumors; however, few studies report its functions in metabolism and metabolic diseases. Here we aimed to explore the novel role and regulation mechanism of TWIST2 in hepatic steatosis. Our results showed that Twist2 knockdown caused mice obesity, insulin resistance, and hepatic steatosis, which were accompanied with inflammation, endoplasmic reticulum stress, and mitochondrial dysfunction. In vitro, TWIST2 overexpression ameliorated hepatocellular steatosis, inhibited inflammation, and improved mitochondrial content and function with a fibroblast growth factor 21 (FGF21)-dependent pattern. NF-κB negatively regulated FGF21 transcription by directly binding to FGF21 promoter DNA, which was eliminated by TWIST2 overexpression by inhibiting NF-κB expression and translocation to nucleus. TWIST2 overexpression decreased intracellular reactive oxygen species level, increased mitochondrial DNA and biogenesis, and enhanced ATP production and antioxidation ability. Additionally, TWIST2 expression was repressed by insulin-targeting sterol regulatory element-binding protein 1c (SREBP1c) and forkhead box protein O1 and was enhanced by dexamethasone targeting Krüppel-like factor 15, which directly interacted with Twist2 promoter DNA. Together, our studies identify an important role and regulation mechanism of TWIST2 in maintaining hepatic homeostasis by ameliorating steatosis, inflammation, and oxidative stress via the NF-κB-FGF21 or SREBP1c-FGF21 pathway, which may provide a new therapeutic scheme for nonalcoholic fatty liver disease.-Zhou, L., Li, Q., Chen, A., Liu, N., Chen, N., Chen, X., Zhu, L., Xia, B., Gong, Y., Chen, X. KLF15-activating Twist2 ameliorated hepatic steatosis by inhibiting inflammation and improving mitochondrial dysfunction via NF-κB-FGF21 or SREBP1c-FGF21 pathway.

Methamidophos Influences Midgut Proteinase Activity and Subcellular Structures in the Wolf Spider Pardosa pseudoamulata (Araneae: Lycosidae).

A piezoelectric quartz crystal impedance (PQCI) sensor was used to investigate influences of the insecticide methamidophos on proteinase activity in midguts of the wolf spider, Pardosa pseudoamulata (Araneae: Lycosidae). Results from PQCI indicated that low-concentration dose methamidophos (0.008%) can activate the proteinase but high-concentration dose methamidophos (0.016-0.032%) can inhibit the enzyme activity. The changes in subcellular structure of spider midgut cells were also observed. Electron micrographs of spider midgut epithelial cells showed that the low-dose methamidophos did not visibly impact the structure of these cells. Conversely, high-concentration dose methamidophos led to severe changes in the cell structure, including the karyotheca dissolved, the nucleolus, and the endoplasmic reticulum disappeared. These may contribute to changes in proteinase activity of spider. This work documents a feasible method for rapid and reliable detection of proteinase activity.

Biotoxicity of Cry1Ab protein on wolf spider Pardosa pseudoannulata.

In this research, we carried out a tritrophic bioassay to assess the potential effect of Cry1Ab-expressing rice on the foraging behavior of the common wolf spider Pardosa pseudoannulata and its underlying molecular mechanism. Results indicated the Bt-containing spiders expressed a higher foraging range when compared to controls. The high throughput de novo transcriptome sequencing was further carried out for central nervous system (CNS) of P. pseudoannulata with and without Cry1Ab intake. We obtained 120, 985 unigenes with a mean length of 529.73 bp. Functional analysis of differentially expressed genes (DEGs) showed the expression levels of genes related to energy metabolism were changed in response to Cry1Ab, which may contribute to a more active foraging behavior. In addition, some DEGs also have a function related to metal ion binding, implying a potential influence on metal ions-dependent reactions. This may be associated with Cry1Ab resistance mechanism in the spider.