Protective Effect And Mechanism Of Tetramethylpyrazine On LPS Induced Impaired Glycocalyx Of Kidney Endothelial Cells In AKI Mice

Background:Acute kidney injury(AKI)is a common clinical comprehensive and complex disease syndrome,loss of renal function is mainly caused by glomerular filtration decreased rapidly.In the glomeruli,glomerular filtration barrier is an important part of selective filtration of blood vessels,the endothelial cells,as an important part of the glomerular filtration barrier,are covered by glycocalyx,which is a negatively charged network of glycoproteins,proteoglycans and soluble biomacromolecule,is an important part of high selectivity through the glomerular wall.Heparan sulfate as an important component of the glycocalyx,its shedding or degradation will involve the morphological and functional changes of glomerular endothelial cells.Tetramethylpyrazine,a natural compound of active alkaloid isolated from Ligusticum wallichii(Chuan Xiong),has shown biological effects such as anti-inflammatory,anti-cancer,anti-oxidative and antiapoptosis.The purpose of our study is to investigate the pathogenesis of AKI induced by lipopolysaccharide.Study on the mechanism of TMP on AKI induced by LPS though experimental animal kidney pathology observation,urine protein,serum creatinine,serum urea nitrogen,MDA,ROS,SOD oxidation indicators of renal tissue and endothelial cells,HS fluorescence mechanism of renal tissue and endothelial cells.To evaluate the effect of TMP on the prevention and treatment of AKI caused by LPS,and to provide a new theoretical basis for the clinical diagnosis and treatment of AKI.Methods:In vivo exqeriment:Male C57BL/6 mice were randomly divided into 5 gropns:control group,model group(Lps group 10 mg/kg),treatment group(lps+tmp group 50 mg/kg,100 mg/kg,200 mg/kg),normal group)and model group were given normal saline for 1 week.The treatment group was given TMP(50 mg/kg,100 mg/kg,200 mg/kg)respectively for one week.Injection of lipopolysaccharide after 1 hour of gavage on Day 7,the blood and kidney were collected and preserved 24 hours after intraperitoneal injection of LPS.HE staining was used to evaluate renal injury.Permeability of renal capillaries was measured by Evans blue dye.Serum urea nitrogen,serum creatinine and SOD,MDA,ROS of kindey tissue were detected by corresponding kit.The content of HS in renal tissue was detected by immunofluorescence.In vitro,human umbilical vein endothelial cells were divided into 5 groups.Normal group,model group(Lps 1 ?g/ml),the treatment group(lps+tmp 100?M/ml,200 ?M/ml,300 ?M/ml).The corresponding kit was used to detect the content of MDA,SOD in the cells,and immunofluorescence was used to detect the content of ros,changes of mitochondrial membrane potential and the content of HS on the membrane surface in cellResults:Compared with the normal group,the renal tissue injury in the model group was obviously serious,the concentration of evans blue in the renal tissue,serum urea nitrogen,serum creatinine were significantly increased in the model group,but in the treatment group,especially in the middle and high dose group.It can effectively reduce the degree of renal injury,can significantly reduce the content of Evans blue in the renal tissue,serum urea nitrogen,serum creatinine.At the same time,TMP can protect the integrity of endothelial glycocalyx and the integrity of glomerular capillaries by reducing the stress response in vivo and protecting mitochondrial membrane potential,which inhibits hs shedding or degradation caused by LPS.In turn,the renal injury induced by LPS was alleviated.Conclusions:In conclusion,this study demonstrated that tetramethylpyrazine protects the integrity of the glycocalyx and helps to alleviate lipopolysaccharide induced acute kidney injury.This study is beneficial to the development of glycocalyx protective drugs as a potential target for the treatment of AKI.