ABSTRACT
ObjectiveTo observe the mechanism of modified Shengjiangsan in necroptosis and renal fibrosis of rats with diabetic nephropathy based on receptor-interacting protein （RIP）1/RIP3/mixed lineage kinase domain-like protein （MLKL） signaling pathway. MethodSeventy-five SD rats were randomly divided into a model group， a normal group， three high， medium， and low-dose modified Shengjiangsan groups （4.365， 8.73， 17.46 g·kg-1）， and an irbesartan group （0.013 5 g·kg-1）. After 4 weeks of intragastric administration， the levels of 24 h urine protein （UTP）， tumor necrosis factor-α （TNF-α）， and interleukin-1β （IL-1β） of rats in each group were determined， as well as the changes in degree of renal pathology. Real-time quantitative polymerase chain reaction （Real-time PCR） and immunohistochemistry were used to detect the mRNA and protein expression levels of IL-1β， TNF-α， monocyte chemoattractant protein-1 （MCP-1）， transforming growth factor-β1 （TGF-β1）， and nuclear factor kappa B （NF-κB） in kidney tissues of rats. Western blot assay was used to detect the expression levels of key proteins in the RIP1/RIP3/MLKL signaling pathway. ResultAs compared with the normal group， the renal interstitial fibrosis in the model group was obvious， and the 24 h UTP， IL-1β， TNF-α levels were significantly increased （P<0.05）. In the model group， the mRNA and protein expression levels of IL-1β， TNF-α， MCP -1， TGF-β1， and NF-κB in the kidney tissues were significantly increased （P<0.05）， and protein expression levels of RIP1， RIP3， p-MLKL， and MLKL were significantly increased （P<0.05）. Compared with the model group， all modified Shengjiangsan groups and the irbesartan group improved the levels of renal interstitial fibrosis in rats to varying degrees. As compared with the model group， the 24 h UTP levels in all modified Shengjiangsan groups and the irbesartan group were decreased to varying degrees （P<0.05）， the content of IL-1β and TNF-α in the serum were decreased （P<0.05）， the mRNA and protein expression levels of IL-1β， TNF-α， MCP-1， TGF-β1， and NF-κB in renal tissues was down-regulated （P<0.05）， and the protein expression levels of RIP1， RIP3， p-MLKL， and MLKL were down-regulated （P<0.05）. ConclusionModified Shengjiangsan ameliorates renal injury of rats with diabetic nephropathy， and the mechanism may be related to the down-regulation of the RIP1/RIP3/MLKL signaling pathway， the prevention of renal tissue necroptosis， and the inhibition of renal fibrosis.