Role Of Autophagy Regulated By JNK Signaling Pathway In The Prevention And Treatment Of Diabetic Nephropathy With Curcumin Derivative C66

As a metabolic disease,diabetic nephropathy has been receiving more and more attention.It is generally believed that inflammatory cell infiltration,oxidative stress injury,high-glucose intake and environmental factors are involved in the pathological process.The curcumin derivative C66 is a curcumin-like compound with stable properties and high bioavailability,which is considered to have the effects of resisting oxidation,inflammation and improving the severity of fibrosis.This study attempts to explore new ideas for the prevention and treatment of diabetic nephropathy by detecting the JNK signaling pathway in diabetic kidney and the levels of proteins related to autophagy regulated by JNK signaling pathway.First,the mice were randomly divided into 8 groups(4 groups of JNK1 knockout mice and 4 groups of C57BL/6J mice).A lower dose(50 mg/kg)of STZ was injected once per day for continuous five days to induce jnk1 knockout mice or homologous C57BL/6J mice to form the type I diabete mouse model.One group from each strain of mice was randomly selected as the treatment group: C66 gavage was performed with a dose of 5 mg/kg from the date of modeling,once every other day,and the remaining groups were given an equal volume of 1% sodium carboxymethylcellulose(1% CMC-Na),with the experimental period of 3 months.The blood glucose levels of mice were measured,the urine was collected and the body weight was recorded every two weeks.At the end of the experiment,the basic physiological indexes and renal function indexes were detected;the pathological sections were made for PAS,PASM and Masson staining;the glomerular morphology was observed using transmission electron microscopy;the related inflammation and fibrosis indexes were detected by RT-PCR and Western Blotting methods.The results showed that the levels of proinflammatory factors ICAM-1,VCAM-1 and MCP-1,pro-fibrotic factors TGF-?,CTGF and MCP-1 were increased in the diabetic mice group,the expression was decreased after C66 treatment,and the lesion of jnk1 knockout group with diabetes was milder than that of C57BL/6J mice group.Next,we examined the effect of C66 on the activity of JNK pathway,observed the expression of autophagy-related proteins Beclin-1,LC3II/LC3 I,and p62,and explored the level changes of key factors m TOR and PI3 K that regulate autophagy.Through all the experiments above,we analyzed the role of JNK signaling pathway in the prevention and treatment of diabetic nephropathy with C66.The study found that C66 intervention and jnk1 gene knockout could effectively reduce the level of phosphorylated JNK(p-JNK)in diabetic kidney,the expression of autophagy-related proteins Beclin-1 and LC3II/LC3 I in diabetic mice was increased,while the m RNA exprission of p62 was decreased,and the activation of PI3 K could up-regulate the level of phosphorylated m TOR(p-m TOR)and thus affect the autophagy activity.In summary,the following conclusions have been drawn from the study: 1.C66 plays a protective role in diabetic kidney by inhibiting the activity of JNK pathway;2.The therapeutic effect of jnk1 knockout mice group with diabetes is better than that of homologous C57BL/6J mice group;3.Through up-regulating the expression by way of receiving two-way regulation in diabetic nephropathy,the autophagy activity can not only receive the stimulation of high glucose environment,but also get the regulation by C66 and jnk1 gene knockout.