JAB1 promotes palmitate-induced insulin resistance via ERK pathway in hepatocytes

Network pharmacology, molecular docking and experimental validation to elucidate the anti-T2DM mechanism of Lanxangia tsaoko

Lanxangia tsaoko (L. tsaoko) is a natural medicine which could be used to treat type 2 diabetes mellitus (T2DM). However, there is no systematic and comprehensive research on the its active compounds and mechanism. This study aimed to investigate the active ingredients and potential mechanism of L. tsaoko for the treatment of T2DM. The chemical constituents of L. tsaoko were identified by UPLC-Q-Exactive Orbitrap/MS. The active compounds and mechanism of L. tsaoko were predicted by network pharmacology. Then the docking modes of key components and core targets were analyzed by molecular docking. Finally, animal experiments were conducted to verify the efficacy and targets of L. tsaoko in T2DM treatment. 70 compounds from L. tsaoko were identified. We obtained 37 active components, including quercetin, genistein and kaempferol, 5 core targets were AKT1, INS, TP53, TNF and IL-6. Mainly involved in PI3K/Akt, MAPK, RAGE/AGE, HIF-1, FoxO signaling pathways. Molecular docking results showed that the L. tsaoko had good binding potential to TNF. Therefore, we took the inflammatory mechanism as the prediction target for experimental verification. Animal experiments showed that L. tsaoko could alleviated colon injury of T2DM mice, improve glucose metabolism and decrease inflammatory levels. L. tsaoko exerted therapeutic effects on T2DM through multi-component, multi-target and multi-pathway regulation. Its action mechanisms were related to PI3K/Akt, MAPK, RAGE/AGE, HIF-1 and FoxO signaling pathways. This study provided new insights for the clinical treatment of T2DM.

ZFYVE28 mediates insulin resistance by promoting phosphorylated insulin receptor degradation via increasing late endosomes production

Insulin resistance is associated with many pathological conditions, and an in-depth understanding of the mechanisms involved is necessary to improve insulin sensitivity. Here, we show that ZFYVE28 expression is decreased in insulin-sensitive obese individuals but increased in insulin-resistant individuals. Insulin signaling inhibits ZFYVE28 expression by inhibiting NOTCH1 via the RAS/ERK pathway, whereas ZFYVE28 expression is elevated due to impaired insulin signaling in insulin resistance. While Zfyve28 overexpression impairs insulin sensitivity and causes lipid accumulation, Zfyve28 knockout in mice can significantly improve insulin sensitivity and other indicators associated with insulin resistance. Mechanistically, ZFYVE28 colocalizes with early endosomes via the FYVE domain, which inhibits the generation of recycling endosomes but promotes the conversion of early to late endosomes, ultimately promoting phosphorylated insulin receptor degradation. This effect disappears with deletion of the FYVE domain. Overall, in this study, we reveal that ZFYVE28 is involved in insulin resistance by promoting phosphorylated insulin receptor degradation, and ZFYVE28 may be a potential therapeutic target to improve insulin sensitivity.

Insulin Resistance and Diabetes Mellitus in Alzheimer's Disease

Type 2 diabetes mellitus is a progressive disease that is characterized by the appearance of insulin resistance. The term insulin resistance is very wide and could affect different proteins involved in insulin signaling, as well as other mechanisms. In this review, we have analyzed the main molecular mechanisms that could be involved in the connection between type 2 diabetes and neurodegeneration, in general, and more specifically with the appearance of Alzheimer's disease. We have studied, in more detail, the different processes involved, such as inflammation, endoplasmic reticulum stress, autophagy, and mitochondrial dysfunction.