PSTPIP2 Inhibits Cisplatin-induced Acute Kidney Injury By Suppressing Apoptosis Of Renal Tubular Epithelial Cells

Cisplatin is a chemotherapeutic drug with significant clinical effects.It has a wide range of applications in the treatment of various solid tumors.However,a series of serious adverse reactions caused by cisplatin,such as acute kidney disease,cannot be ignored.Injury,bone marrow suppression,gastrointestinal reactions,etc.Acute kidney injury can lead to serious disorders of kidney function.Cells in the injured tissue shrink irregularly and easily fall off when the position changes.From the pathological characteristics,the death and proliferation of kidney cells are delayed,and the infiltration of macrophages and the release of inflammatory factors are delayed.There are many causes of acute kidney injury,such as ischemia-reperfusion,nephrotoxic drugs and sepsis.At present,there is no good solution for acute kidney injury induced by cisplatin.Proline-serine-threonine phosphatase interacting protein 2(PSTPIP2)is a skeletal protein located on the cell membrane.It is involved in innate immunity and autoinflammatory diseases.It inhibits the occurrence of inflammation and stimulates The activity of phages participates in the movement of neutrophils and the differentiation of osteoclasts.Recently,we discovered the specific role of proline-serine-threonine phosphatase interacting protein 2(PSTPIP2)in cisplatin-induced acute kidney injury.However,the role of PSTPIP2 in the experimental model of cisplatin-induced acute kidney injury has not been extensively studied.In this study,we found that PSTPIP2 is under-expressed in both acute kidney injury mice and HK2 cells,and the relationship between PSTPIP2 and acute kidney injury is still unclear.Whether it is involved in renal tubular epithelial apoptosis requires further investigation.Experimental exploration.To further explore the role of PSTPIP2 protein in acute kidney injury.In this study,C57 male mice and HK2 cell lines were used as the research objects.The effects of PSTPIP2 on renal tubular epithelium in acute kidney injury were observed through in vivo and in vitro experiments.The main research content of this topic includes the following 4 parts:1.Explore the expression of PSTPIP2 in vivo and in vitro in acute kidney injuryIn this study,we first judged the success of the model based on the pathological sections of the mouse kidney and the biochemical indicators of the serum,and then isolated the mouse kidneys and used Western blot to detect the expression of PSTPIP2 at the protein level,and found that the expression of PSTPIP2 was reduced.HK2 cells were used to induce acute kidney injury in vitro.Western blot analysis showed that KIM1 was significantly up-regulated and PSTPIP2 expression was down-regulated.Immunofluorescence staining showed that the expression patterns of KIM-1 and PSTPIP2 were similar.Taken together,these results indicate that PSTPIP2 expression is reduced in cisplatin-treated mice and cisplatin-treated HK-2 cells.2.In vivo verification of the role of PSTPIP2 in acute kidney injuryRAAV9–PSTPIP2 was injected through the tail vein and r AAV9 was injected as a control group.After the model was established,the success of the model was verified by pathological sections of kidney tissue,changes in mouse body weight and changes in serum indexes.Macroscopically,r AAV9-PSTPIP2 can significantly improve renal function and improve the protection of kidney morphology.PAS staining histological analysis showed that compared with the CP group,the tissue damage in the r AAV9-PSTPIP2 group was significantly reduced.Compared with the CP group,the r AAV9-PSTPIP2 group increased slightly.Similar to the normal group,similarly,r AAV9-PSTPIP2 significantly reduced the increase in GR and BUN levels.Western blot analysis showed that the expression of KIM-1 protein was significantly up-regulated in the CP treatment group,while r AAV9-PSTPIP2 could reduce the expression of KIM-1 protein.These results indicate that PSTPIP2 can significantly slow down the acute kidney injury caused by cisplatin.3.Verification of STPIP2 inhibiting apoptosis in vivo and in vitroOn the basis of successful viral infection,TUNEL staining was used to detect the apoptotic changes in the kidney tissues of each group of mice,and Western blot was used to detect changes in the apoptosis marker protein Capase-3.The results showed that PSTPIP2 can inhibit kidney apoptosis,and at the same time Transfect HK2 cells with p EX-2-PSTPIP2 and si RNA-PSTPIP2,up-regulate and down-regulate the expression of PSTPIP2 in HK2 cells,and further detect the expression levels of Kim-1and Capase-3 proteins by Western blot,and quantitatively analyze by draining cytometry Apoptotic changes.The results showed that after overexpression of PSTPIP2,the apoptotic index was significantly reduced,and after the silencing of PSTPIP2,the apoptotic index was significantly increased.Both in vivo and in vitro results show that PSTPIP2 plays an anti-apoptotic effect in acute kidney injury.4.Further explore the protective mechanism of PSTPIP2 on acute kidney injury through HDAC inhibitorsWe have studied the epigenetic mechanism of PSTPIP2 regulation.Find the enrichment sites of epigenetic markers through the data of UCSC genome browser.Chromatin immunoprecipitation(Ch IP)test found that cisplatin treatment reduced histone acetylation in the promoter region of PSTPIP2 gene.The results indicate that TSA up-regulates H3K27 Ac protein expression.Compared with the CP group,the expression of KIM-1 and Caspase-3 proteins in the CP and TSA treatment groups was down-regulated.