Impact of regulating the RANKL/RANK/TLR4 signaling pathway on sepsis-associated acute kidney injury
NIU Xinrong
LI Hui
CHEN Weilin
Abstract：Objective To investigate the role and possible mechanisms of the receptor activator of nuclear factor-κB ligand(RANKL)/receptor activator of nuclear factor-κB(RANK)/toll-like receptor 4(TLR4)signaling pathway in the inflammatory response of sepsis-associated acute kidney injury(SA-AKI).Methods Twenty-four male C57BL/6 mice were randomly assigned into the sham operation group(S group),cecal ligation and puncture(CLP)-induced sepsis model group(C group),recombinant RANKL pretreatment group(R group),and anti-RANKL pretreatment group(A group),with 6 mice in each group.Two hours before surgery,CLP-induced in R group and A group were intraperitoneally injected with recombinant RANKL and anti-RANKL antibody,respectively.Blood was collected 24 hours after modeling,and mice were sacrificed to harvest kidney tissue.Creatinine(Scr)and blood urea nitrogen(BUN)levels were measured using commercial kits.Enzyme-linked immunosorbent assay(ELISA)was performed to detect serum interleukin 6(IL-6),IL-1β,and tumour necrosis factor alpha(TNF-α)levels.Hematoxylin and eosin(H&E)staining was performed to observe the histopathological changes in mouse kidney tissue.Reverse transcription quantitative polymerase chain reaction(RT-qPCR)and Western blotting were used to detect the mRNA and protein expression levels of RANKL,RANK,and TLR4 in mouse kidney tissue,respectively.Results Compared with those of S group,mice in the C group had significantly higher serum Scr,BUN,IL-1β,TNF-α,and IL-6 levels.Histopathological assessment of kidney tissue showed partial ischemic shrinkage of renal glomeruli,widening of the glomerular interstitium,necrosis and shedding of renal tubular epithelial cells into the lumen,enlargement of tubular lumens,renal interstitial edema,inflammatory cell infiltration,and a significant increase in renal pathology scores in mice of C group.The mRNA and protein expressions of RANKL in kidney tissue were significantly downregulated,while RANK and TLR4 were significantly upregulated in mice of C group than S group(all P＜0.05).Compared with those of the C group,mice in the R group showed significantly lower serum Scr,BUN,IL-1β,TNF-α,IL-6 levels and pathological scores,alleviated renal damage,higher mRNA and protein expressions of RANKL in kidney tissue,and lower levels of RANK and TLR4(all P＜0.05).In contrast,mice in the A group showed significantly worse renal function,higher inflammatory factor levels,more aggravated kidney damage,lower mRNA and protein expressions of RANKL in kidney tissue,and higher levels of RANK and TLR4 mRNA than those of C group(all P＜0.05).Conclusion Increasing the signal transduction of the RANKL/RANK/TLR4 signaling pathway can alleviate the inflammatory response and protect against CLP-induced acute kidney injury in mice with SA-AKI.
Keywords：sepsisacute kidney injuryreceptor activator of nuclear factor-κB ligand(RANKL)/receptor activator of nuclear factor-κB(RANK)/toll-like receptor 4(TLR4)signaling pathwayinflammatory response
Publication Date：2025-03-26
Online Publishing Date：2025-08-15(First online date of this platform, not the publication date of the document)
Pages：6( 381-385,390 )