SOLUBLE DIETARY FIBER FROM FERMENTED SOYBEAN DREGS ENHANCES GLUCOSE UPTAKE AND MITIGATES INSULIN RESISTANCE IN HUMAN LIVER CANCER CELL (HEPG2) MODEL VIA AMPK/SIRT1 SIGNAL PATHWAY

摘要

In order to explore glucose uptake and elucidate the underlying mechanism of insulin resistance (IR) in human liver cancer cell (HepG2) upon the intervention of soluble dieta?) , fiber (SDF) from fermented soybean dregs, HepG2 cell model with insulin resistance (HepG2/IR) was established to measure the cell viability and glucose uptake by cholecystokinin (CCK) 8 and glucose oxidase (GOD) kits upon SDF intervention. Meanwhile, protein expression of insulin receptor substrate 1 (IRS-1) and protein kinase B (Akt) in HepG2/IR cells treated with SDF was evaluated by Western blot. Moreover, protein expression of Mfn2 and Drpl associated with mitochondrial dynamics in HepG2/IR cells exposed to SDF was detected Our results revealed that SDF increased glucose uptake in HepG2/IR cells, with evidences of up-regulated p-IRS, Akt, p-adenosine, 5'-monophosphate-activated protein kinase (AMPK), silent information regulator 1 (SIRT1) and irisin. Furthermore, SDF restored the balance of mitochondrial dynamics via up-regulating Mfn2, and down-regulating PGC-l alpha and Drpl in insulin-resistant HepG2 cells. In contrast, after blocking SIRT1 by EX527, the glucose uptake of HepG2/IR cells could not be rescued when treated with SDF. Therefore, SDF can mitigate or rescue insulin resistance to improve glucose uptake via regulating AMPK/SIRT1 signal pathway.