Advances in the role of HCV nonstructural protein 5a (NS5A) of 3a genotype in inducing insulin resistance by possible phosphorylation of AKT/PKB

Genome-wide methylation profiling of HCV pathogenesis to develop diabetes and diabetic complications

HCV is key pathological factor for inducting insulin resistance. Such HCV-induced insulin resistance is linked with metabolic syndrome, type 2 diabetes mellitus, extrahepatic manifestations, hepatic fibrosis progression and development of hepatocellular carcinoma. DNA methylation alterations can cause developmental abnormalities, tumours and other diseases. In our study, PBMCs were isolated and genomic DNA was extracted. DNA fragmentation was achieved by sonication to 200-400 bp; subsequently, end repair and adenylation was performed. Manufacturer's guidelines were followed to ligate Cytosine-methylated barcodes to sonicated DNA. EZ DNA Methylation-GoldTM Kit was then employed to treat these DNA segments twice with bisulphite. A Library was maintained, sequenced on an Illumina platform and 150/125 bp paired-end reads generated. GO seq R package was used to perform Gene Ontology (GO) enrichment analysis for genes linked to DMRs and DMPs; gene length bias was corrected. We identified 12 945 significant hypermethylated DMRs among all samples that were screened as those with at least 0.1 methylation level differences and P-value less than 0.05. Fisher's exact test with FDR multiple test correction is used for identification of DMPs and DMRs. High throughput bisulphite sequencing (Illumina) was carried out, and bioinformatics analysis was performed to analyse methylation status. Gene ontology (GO) and KEGG pathway enrichment analysis showed differentially methylated regions enriched in various pathways that include PI3K-AKT/IRS1 signalling pathway, metabolic pathway, oxidative phosphorylation, Renin-angiotensin system that are all involved in developing type-2 diabetes (T2D). Our study provides supporting evidence for significant involvement of HCV infection in development of epigenetic modifications in regulation of metabolic disorders like T2D and its complications.

Insights into the Molecular Mechanisms of Liuwei Dihuang Decoction via Network Pharmacology

The traditional Chinese medicines (TCMs) have been used to treat diseases over a long history, but it is still a great challenge to uncover the underlying mechanisms for their therapeutic effects due to the complexity of their ingredients. Based on a novel network pharmacology-based approach, we explored in this study the potential therapeutic targets of Liuwei Dihuang (LWDH) decoction in its neuroendocrine immunomodulation (NIM) function. We not only collected the known targets of the compounds in LWDH but also predicted the targets for these compounds using the balanced substructure-drug-target network-based inference (bSDTNBI), which is a target prediction method based on network inferring developed by our laboratory. A "target-(pathway)-target" (TPT) network, in which targets of LWDH were connected by relevant pathways, was constructed and divided into several separate modules with strong internal connections. Then the target module that contributes the most to NIM function was determined through a contribution scoring algorithm. Finally, the targets with the highest contribution score to NIM-related diseases in this target module were recommended as potential therapeutic targets of LWDH.

ATG7 regulates hepatic Akt phosphorylation through the c-JUN/PTEN pathway in high fat diet-induced metabolic disorder

Growing evidence has suggested that autophagy-related protein 7 (ATG7) plays an important role in insulin signaling, but the mechanism of ATG7 in hepatic insulin sensitivity is not fully understood. The purpose of the present study is to clarify the underlying molecular mechanisms of ATG7 in obesity development. Serum and liver samples from mice fed a high fat diet (HFD) were evaluated for metabolic profile data and ATG expressions during obesity development. We found that compared with other ATGs, ATG7 expression increased earlier with lower hepatic insulin sensitivity in the 4-wk HFD-fed mice. For in vitro analyses, silencing ATG7 significantly up-regulated insulin-stimulated phosphorylation of protein kinase B (Akt) and down-regulated phosphatase and tension homolog deleted on chromosome ten (PTEN) in HepG2 cells. Replenishing PTEN to ATG7-silenced hepatocytes restored the phosphorylated Akt level. Furthermore, ATG7 silencing led to higher c-JUN expression, which transcriptionally reduced PTEN expression. These results reveal a novel mechanism by which ATG7 regulates Akt phosphorylation via the c-JUN/PTEN pathway at the early stage of HFD-induced metabolic disorder.-Zhao, D., Zhang, S., Wang, X., Gao, D., Liu, J., Cao, K., Chen, L., Liu, R., Liu, J., Long, J. ATG7 regulates hepatic Akt phosphorylation through the c-JUN/PTEN pathway in high fat diet-induced metabolic disorder.