Inhibition Of Semaphorin-3a Suppresses Lipopolysaccharide-induced Acute Kidney Injury

Objective:Semaphorin-3a(Sema3A),a soluble axon guidance cue,appears to play an important role in the development of acute kidney injury(AKI),and has been regarded as an early diagnostic marker to evaluate the progression of AKI.But,the role of Sema3A in sepsis-associated AKI remains unknown.Lipopolysaccharide(LPS)was used to simulate sepsis related AKI in animal model,this study aims to determine the role of Sema3A in LPS-induced AKI in vivo and in vitro.Methods:Male C57BL/6 mice were intraperitoneally injected with LPS(10 mg/kg)to generated AKI model.Renal function was detected by animal blood according to the manufacturer instruction.Kidney tissues sections were stained with hematoxylin and eosin for histopathologic analysis.The expressions of Sema3A,neutrophils,and macrophages were tested by immunohistochemistry.Sema3A expression in kidney tissues was also examined by Western blot.Cell apoptosis in kidney tissues was analyzed by Terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling staining.The expressions of relevant inflammatory proteins in NRK-52E cells were detected by Western blot assay and Fluorescence Microscopy Analysis.Cell apoptosis in NRK-52E cells were measured by Western blot and Flow cytometry.Results:In our in vivo research,Sema3A was found in tubular epithelial cells(TECs),which presented a higher level after LPS treatment.Meanwhile,the results of our in vitro experiment showed that Sema3 A was also elevated in NRK-52E cells treated by LPS.Importantly,inhibition of Sema3A by(-)-epigallocatechin gallate(EGCG)could significantly reduce kidney inflammation in mice and apoptosis of TECs.Likewise,EGCG intervention also ameliorated the inflammation and apoptosis of cells in vitro.Furthermore,our research also found that the Racl/NF-?Bp65 and JNK pathways were possibly involved in the Sema3A-mediated inflammation and apoptosis of TECs,respectively.Conclusion:Our research suggested that Sema3A might play a pathogenic role by promoting inflammation and apoptosis of TECs in LPS-induced AKI.So,Sema3A probably serves as a useful target in ameliorating sepsis associated AKI,it may also be combined with other targets for early treatment of sepsis-associated AKI.