Endothelial HNF4α potentiates angiogenic dysfunction via enhancement of vascular endothelial growth factor resistance in T2DM

LOX-1 attenuates high glucose-induced autophagy via AMPK/HNF4α signaling in HLSECs

Type 2 diabetes mellitus (T2DM) combined with nonalcoholic fatty liver disease (NAFLD) is a common cause of death. Lectin-like oxidized low-density lipoprotein receptor-1 (LOX-1) is involved in the regulation of autophagy and associated with a variety of diseases, such as atherosclerosis, diabetes, and NAFLD. This study aimed to investigate the effect of LOX-1 on autophagy induced by high glucose levels in human liver sinusoidal endothelial cells (HLSECs) and whether it regulates autophagy through the adenosine monophosphate-activated protein kinase/hepatocyte nuclear factor 4α (AMPK/HNF4α) pathway. In this study, HLSECs cultured with high glucose medium showed increased expression of LOX-1, whereas autophagy was inhibited. High glucose levels decreased the AMPK phosphorylation, increased the HNF4α phosphorylation, and retained the HNF4α in the cytoplasm. By contrast, silencing of LOX-1 reversed the phenomenon induced by high glucose levels and restored the HNF4a localization. Taken together, our findings reveal a novel mechanism of high glucose-induced autophagy in HLSECs, namely, the LOX-1-mediated AMPK/HNF4α signaling pathway. Therefore, LOX-1 is an important target molecule for the regulation of autophagy in HLSECs.

Revealing active components, action targets and molecular mechanism of Gandi capsule for treating diabetic nephropathy based on network pharmacology strategy

Background

Gandi capsule is a traditional Chinese herbal formula used to promote blood circulation and removing blood stasis in clinical. Our previous study has shown that it reduces proteinuria with routine treatment in diabetic nephrophy (DN), but its pharmacological action mechanism is still unknown.

Methods

To facilitate the identification of components, a component database of Gandi capsule and target database of DN were established by ourselves. The components absorbed in blood circle were identified in rat plasma after oral administration of Gandi capsule by UHPLC-QQQ-MS/MS. The potential targets were screened by using Libdock tolls in Discovery studio 3.0. Then Pathway and Network analyses were used to enrich the screened targets. The possible targets were verified by using a surface plasmon resonance (SPR) test and the molecular mechanism focusing these targets for treating DN was clarified by western blot.

Results

Six components in Gandi capsule were identified detected in rat plasma after oral administration by UHPLC-QQQ-MS/MS. After molecular docking analyses in KEGG and Discovery studio, four protein targets including HNF4A, HMGCR, JAK3, and SIRT1, were screened out, and proved as effective binding with baicalin, wogonoside by SPR. And the molecular mechanism was clarified that baicalin and wogonoside inhibit the effect of high glucose (HG)-induced decreased cell viability and podocin expression, and strengthen the activation p-AKT, p-PI3K, and p-AMPK.

Conclusion

Baicalin and wogonoside were screened out to be the active compounds in Gandi capsule and can ameliorate HG-induced podocyte damage by influencing the AMPK and PI3K-AKT signaling pathways by binding with HNF4A, HMGCR, JAK3, and SIRT1.

Graphical abstract

Supplementary Information

The online version contains supplementary material available at 10.1186/s12906-020-03155-4.