Insights into the role of RNA m6A modification in the metabolic process and related diseases.

According to the latest consensus, many traditional diseases are considered metabolic diseases, such as cancer, type 2 diabetes, obesity, and cardiovascular disease. Currently, metabolic diseases are increasingly prevalent because of the ever-improving living standards and have become the leading threat to human health. Multiple therapy methods have been applied to treat these diseases, which improves the quality of life of many patients, but the overall effect is still unsatisfactory. Therefore, intensive research on the metabolic process and the pathogenesis of metabolic diseases is imperative. N6-methyladenosine (m6A) is an important modification of eukaryotic RNAs. It is a critical regulator of gene expression that is involved in different cellular functions and physiological processes. Many studies have indicated that m6A modification regulates the development of many metabolic processes and metabolic diseases. In this review, we summarized recent studies on the role of m6A modification in different metabolic processes and metabolic diseases. Additionally, we highlighted the potential m6A-targeted therapy for metabolic diseases, expecting to facilitate m6A-targeted strategies in the treatment of metabolic diseases.

Berberine improves DSS-induced colitis in mice by modulating the fecal-bacteria-related bile acid metabolism.

Ulcerative colitis (UC) has been confirmed as a disease with a high incidence and low cure rate worldwide. In severe cases, UC can develop into colon cancer. Modern research has confirmed that berberine (BBR) can treat UC by inhibiting the expressions of inflammatory factors. However, the contribution of gut microbiota and flora metabolites in treating UC with BBR remains unclear. In this study, the ameliorative effects of BBR on gut microbiota dysbiosis and flora metabolites were investigated in a dextran sodium sulfate (DSS)-induced UC rodent model. We found that BBR significantly improved the pathological phenotype, attenuated intestinal barrier disruption, and mitigated colonic inflammation in DSS mice. By 16 S rDNA sequencing, BBR alleviated gut microbiota dysbiosis in UC mice. Moreover, the gut microbiota depletion experiment confirmed that the therapeutic effect of BBR was inextricably correlated with the gut microbiota. Besides, the flora metabolites (e.g., short-chain fatty acids, bile acids, and 5-hydroxytryptamine) were studied using HPLC-MS. The results suggested that BBR ameliorated the bile acid imbalance induced by DSS in the liver and gut. Furthermore, BBR treatment repaired gut barrier damage. The above results revealed that BBR alleviated DSS-induced UC in mice by restoring the disturbed gut microbiota, elevating unconjugated and secondary bile acids in the gastrointestinal tract, and activating the FXR and TGR5 signal pathway. This study provides novel insights into the mechanism of BBR in treating UC.

Tannic Acid Suppresses HBV Replication via the Regulation of NF-κB, MAPKs, and Autophagy in HepG2.2.15 Cells.

Hepatitis B virus (HBV) infection is a serious global health problem that threatens the health of human. Tannic acid (TA), a natural polyphenol in foods, fruits, and plants, exhibits a variety of bioactive functions. In our research, we decide to explore the pharmacological mechanism of TA against HBV replication. Our results showed that TA effectively reduced the content of HBV DNA and viral antigens (HBsAg and HBeAg) in HepG2.2.15 cells. Meanwhile, TA significantly decreased the mRNA expression of HBV RNA, which include total HBV RNA, HBV pregenomic RNA, and HBV precore mRNA. Besides, TA evidently downregulated the activity of HBV promoters in HepG2.2.15 cells. Furthermore, we found that TA upregulated the expression of IL-8, TNF-α, IFN-α, and IFN-α-mediated antiviral effectors in HepG2.2.15 cells. On the contrary, TA downregulated the expression of IL-10 and hepatic nuclear factor 4 (HNF4α). In addition, TA activated the NF-κB and MAPK pathways that contributed to the inhibition of HBV replication. Finally, TA treatment led to the occurrence of autophagy, which accelerated the elimination of HBV components in HepG2.2.15 cells. Taken together, our results elucidated the suppressive effect of TA on HBV replication and provided inspiration for its clinical application in HBV treatment.

Structural characterization and anti-inflammatory activity of polysaccharides from Astragalus membranaceus.

In this study, two homogeneous polysaccharides (APS-A1 and APS-B1) were isolated from Astragalus membranaceus by DEAE-52 cellulose and Sephadex G-100 column chromatography. Their chemical structures were characterized by molecular weight distribution, monosaccharide composition, infrared spectrum, methylation analysis, and NMR. The results revealed that APS-A1 (2.62 × 106 Da) was a 1,4-α-D-Glcp backbone with a 1,4,6-α-D-Glcp branch every ten residues. APS-B1 (4.95 × 106 Da) was a heteropolysaccharide composed of glucose, galactose, and arabinose (75.24:17.27:19.35). Its backbone consisted of 1,4-α-D-Glcp, 1,4,6-α-D-Glcp, 1,5-α-L-Araf and the sidechains composed of 1,6-α-D-Galp and T-α/ß-Glcp. Bioactivity assays showed that APS-A1 and APS-B1 had potential anti-inflammatory activity. They could inhibit the production of inflammatory factors (TNF-α, IL-6, and MCP-1) in LPS-stimulated RAW264.7 macrophages via NF-κB and MAPK (ERK, JNK) pathways. These results suggested that the two polysaccharides could be potential anti-inflammatory supplements.

YuPingFengSan ameliorates LPS-induced acute lung injury and gut barrier dysfunction in mice.

ETHNOPHARMACOLOGICAL RELEVANCE: Yupingfengsan (YPFS) is a traditional Chinese medicine decoction. YPFS comprises Astragalus mongholicus Bunge (Huangqi), Atractylodes rubra Dekker (Baizhu), and Saposhnikovia divaricata (Turcz.ex Ledeb.) Schischk (Fangfeng). YPFS is commonly used to treat chronic obstructive pulmonary disease, asthma, respiratory infections, and pneumonia, but the mechanism of action remains unclear. AIM OF THE STUDY: Acute lung injury (ALI) and its severe form of acute respiratory distress syndrome (ARDS) cause morbidity and mortality in critical patients. YPFS is a commonly used herbal soup to treat respiratory and immune system diseases. Nevertheless, the effect of YPFS on ALI remains unclear. This study aimed to investigate the effect of YPFS on lipopolysaccharide (LPS)-induced ALI in mice and elucidate its potential molecular mechanisms. MATERIALS AND METHODS: The major components of YPFS were detected by High-performance liquid chromatography (HPLC). C57BL/6J mice were given YPFS for seven days and then treated with LPS. IL-1ß, IL-6, TNF-α, IL-8, iNOS, NLRP3, PPARγ, HO-1, ZO-1, Occludin, Claudin-1, AQP3, AQP4, AQP5, ENaCα, ENaCß, EnaCγ mRNA in lung and ZO-1, Occludin, Claudin-1, AQP3, AQP4, AQP5, ENaCα, ENaCß, and EnaCγ mRNA in colon tissues were measured by Real-Time Quantitative PCR (RT-qPCR). The expressions of TLR4, MyD88, NOD-like receptor thermal protein domain associated protein 3 (NLRP3), ASC, MAPK signaling pathway, Nrf2, and HO-1 in the lung were detected by Western blot. Plasma inflammatory factors Interleukin (IL)-1ß, IL-6, and Tumor Necrosis Factor-α (TNF-α) were determined by Enzyme-linked Immunosorbent Assay (ELISA). Lung tissues were processed for H & E staining, and colon tissues for HE, WGA-FITC, and Alcian Blue staining. RESULTS: The results showed that YPFS administration alleviated lung injury and suppressed the production of inflammatory factors, including IL-1ß, IL-6, and TNF-α. Additionally, YPFS reduced pulmonary edema by promoting the expressions of aquaporin and sodium channel-related genes (AQP3, AQP4, AQP5, ENaCα, ENaCß, and EnaCγ). Further, YPFS intervention exhibited a therapeutic effect on ALI by inhibiting the activation of the NLRP3 inflammasome and MAPK signaling pathways. Finally, YPFS improved gut barrier integrity and suppressed intestinal inflammation in LPS-challenged mice. CONCLUSIONS: YPFS protected mice against LPS-induced ALI by attenuating lung and intestinal tissue damage. This study sheds light on the potential application of YPFS to treat ALI/ARDS.

Dihydromyricetin inhibits Hepatitis B virus replication by activating NF-κB, MAPKs, and autophagy in HepG2.2.15 cells.

BACKGROUND: Hepatitis B virus (HBV) infection is a severe global health problem, and there has been no effective method to eliminate HBV. This study was designed to explore the pharmacological mechanism of Dihydromyricetin (DHM) treatment on HBV replication in vitro. METHODS AND RESULTS: DHM is a flavonoid compound from Ampelopsis grossedentata. Using HepG2.2.15 cells, which can stably express HBV in vitro, we demonstrated that DHM treatment dramatically reduced HBV replication and secretions of HBsAg and HBeAg. Meanwhile, DHM inhibited mRNA expression of HBV RNAs in HepG2.2.15 cells, including Total HBV RNA, HBV pregenomic RNA (pgRNA), and HBV precore mRNA (pcRNA). Also, DHM elevated the mRNA expressions of inflammatory cytokines and antiviral effectors. In contrast, DHM decreased the mRNA level of HNF4α, which positively correlated with HBV replication. Further studies show that the activation of nuclear factor-kappa B (NF-κB) and mitogen-activated protein kinase (MAPK) signaling pathway played a critical role in DHM-initiated inhibition of HBV replication in HepG2.2.15 cells. Besides, activated autophagy was another contributor that may accelerate the clearance of HBV components. CONCLUSION: In summary, DHM could suppress HBV replication by activating NF-κB, MAPKs, and autophagy in HepG2.2.15 cells. Our studies shed light on the future application of DHM for the clinical treatment of HBV infection.

Reprogramming epiblast stem cells into pre-implantation blastocyst cell-like cells.

Recently, a new wave of synthetic embryo systems (SESs) has been established from cultured cells for efficient and ethical embryonic development research. We recently reported our epiblast stem cell (EPISC) reprogramming SES that generates numerous blastocyst (BC)-like hemispheres (BCLH) with pluripotent and extraembryonic cell features detected by microscopy. Here, we further explored the system over key time points with single-cell RNA-sequencing analysis. We found broad induction of the 2C-like reporter MERVL and RNA velocities diverging to three major cell populations with gene expression profiles resembling those of pluripotent epiblast, primitive endoderm, and trophectoderm. Enrichment of those three induced BC-like cell fates involved key gene-regulatory networks, zygotic genome activation-related genes, and specific RNA splicing, and many cells closely resembled in silico models. This analysis confirms the induction of extraembryonic cell populations during EPISC reprogramming. We anticipate that our unique BCLH SES and rich dataset may uncover new facets of cell potency, improve developmental biology, and advance biomedicine.

Quinolinate Phosphoribosyltransferase is an Antiviral Host Factor Against Hepatitis C Virus Infection.

HCV infection can decrease NAD+/NADH ratio, which could convert lipid metabolism to favor HCV replication. In hepatocytes, quinolinate phosphoribosyl transferase (QPRT) catabolizes quinolinic acid (QA) to nicotinic acid mononucleotide (NAMN) for de novo NAD synthesis. However, whether and how HCV modulates QPRT hence the lipogenesis is unknown. In this work, we found QPRT was reduced significantly in livers of patients or humanized C/OTg mice with persistent HCV infection. Mechanistic studies indicated that HCV NS3/4A promoted proteasomal degradation of QPRT through Smurf2, an E3 ubiquitin-protein ligase, in Huh7.5.1 cells. Furthermore, QPRT enzymatic activity involved in suppression of HCV replication in cells. Activation of QPRT with clofibrate (CLO) or addition of QPRT catabolite NAD both inhibited HCV replication in cells, probably through NAD+-dependent Sirt1 inhibition of cellular lipogenesis. More importantly, administration of CLO, a hypolipidemic drug used in clinics, could significantly reduce the viral load in HCV infected C/OTg mice. Take together, these results suggested that HCV infection triggered proteasomal degradation of QPRT and consequently reduced de novo NAD synthesis and lipogenesis, in favor of HCV replication. Hepatic QPRT thus likely served as a cellular factor that dampened productive HCV replication.

C1orf61 acts as a tumor activator in human hepatocellular carcinoma and is associated with tumorigenesis and metastasis.

The genomic amplification of chromosome 1q long arm, the chromosomal region containing C1orf61, is a common event in human cancers. However, the expression pattern of chromosome 1 open reading frame 61 (C1orf61) in hepatocellular carcinoma (HCC) and its effects on HCC progression remain unclear. We have previously reported that C1orf61 is highly up-regulated during human embryogenesis. In this study, we report that C1orf61 expression is associated with the progression of liver disease. We found that C1orf61 is up-regulated in hepatic cirrhosis tissues and is further up-regulated in primary HCC tumors. Moreover, hepatitis B virus (HBV)-positive patients exhibited significantly higher levels of C1orf61 expression than HBV-negative patients. The evaluation of highly malignant HCC cell lines revealed high protein expression levels of C1orf61. Furthermore, the C1orf61 protein was found to be predominantly distributed within the cytoplasm. The ectopic expression of C1orf61 in the nonmalignant L02 cell line promoted cellular proliferation and colony formation in vitro, as well as cell cycle progression via the regulation of the expression of specific cell cycle-related proteins. In addition, the overexpression of C1orf61 in L02 cells facilitated cellular invasion and metastasis. The down-regulation of epithelial markers (E-cadherin and occludin) and the up-regulation of mesenchymal markers (N-cadherin, vimentin, and snail) suggested that the overexpression of C1orf61 induced the epithelial-mesenchymal transition (EMT) that is linked to metastasis. Taken together, our findings demonstrate, for the first time, the roles of C1orf61 in HCC tumorigenesis and metastasis.

Human T-cell leukemia virus type 1 oncoprotein tax represses ZNF268 expression through the cAMP-responsive element-binding protein/activating transcription factor pathway.

Expression of the human T-cell leukemia virus type 1 (HTLV-1) oncoprotein Tax is correlated with cellular transformation, contributing to the development of adult T-cell leukemia. In this study, we investigated the role of Tax in the regulation of the ZNF268 gene, which plays a role in the differentiation of blood cells and the pathogenesis of leukemia. We demonstrated that ZNF268 mRNA was repressed in HTLV-1-infected cells. We also showed that stable and transient expression of HTLV-1 Tax led to repression of ZNF268. In addition, by using reporter constructs that bear the human ZNF268 promoter and its mutants, we showed that Tax repressed ZNF268 promoter in a process dependent on a functional cAMP-responsive element. By using Tax, cAMP-responsive element-binding protein (CREB)-1, CREB-2, and their mutants, we further showed that Tax repressed ZNF268 through the CREB/activating transcription factor pathway. Electrophoretic mobility shift assays and chromatin immunoprecipitation demonstrated the formation of the complex of Tax.CREB-1 directly at the cAMP-responsive element both in vitro and in vivo. These findings suggest a role for ZNF268 in aberrant T-cell proliferation observed in HTLV-1-associated diseases.