Background: Radix Astragali (Astragalus membranaceus var. mongholicus (Bunge)) and Coptis chinensis (Coptis chinensis var. angustiloba) are two commonly prescribed traditional Chinese herbs for diabetes. Astragalus Polysaccharide (AP) and Berberine (BBR) are active ingredients of these two herbs respectively and they are scientifically proved to have immunomodulatory and anti-inflammatory effects. They are also known for their antidiabetic potential by ameliorating insulin resistance (IR). AP and BBR have shown different advantages in treating diabetes according to previous reports. However, very few studies focus on the combined activities of the two potential antidiabetic ingredients. In this study, we discovered that reactive oxygen species (ROS) accumulated in IR-hepG2 cells and APBBR can decrease ROS level in model group significantly. We conjectured that APBBR can ameliorate IR in hepG2 cells by decreasing ROS level. In order to verify this hypothesis, we obtained phenotype and transcriptome information of IR-HepG2 cells and explore the underlying mechanism of the combination of AP and BBR(APBBR) activity on the relationship between ROS change in IR at whole-transcriptome level, so as to shed new light to efficacy and application of APBBR in treating diabetes.
Methods: The IR cell model was established with high-level insulin intervention. Glucose content, HepG2 cell viability as well as ROS level was detected to study the effect of IR-hepG2 cell phenotype. Unbiased genome-wide RNA sequencing was used to investigate alterations in experimental groups. Then, GO and KEGG functional enrichment was performed to explore the function and pathway of target genes. Venn analysis found out the differentially expressed lncRNAs that had close relationship with IR and ROS. Finally, we screened out candidate lncRNAs and these target genes to construct interaction network of differentiated lncRNA-miRNA-mRNA by according to the principle of competitive endogenous RNA (ceRNA).
Results: The biochemical experiments showed that APBBR administration could improve the proliferation activity of IR-HepG2 cells and decrease ROS level in model cells. The GO and KEGG functional enrichment analyses demonstrated several mRNAs remarkably enriched in biological processes and signaling pathways related to ROS production and IR progression. Interaction network suggest that APBBR ameliorates IR in HepG2 cells by regulating the expression of multiple genes and activating relevant signaling pathway to decrease ROS level. Thus, we demonstrated that APBBR ameliorated IR in hepG2 cells via the ROS-dependent pathway.
Keywords: Astragalus polysaccharide combined with berberine; Competing endogenous RNA network; IR-HepG2 cell model; Insulin resistance; Long non-coding RNA; Messenger RNA; ROS.
©2020 Lin and Mao.