title: Receptor activator of NF-kappaB and podocytes: towards a function of a novel receptor-ligand pair in the survival response of podocyte injury.
abstract: BACKGROUND
  Glomerulosclerosis correlates with reduction in podocyte number that occurs through mechanisms which include apoptosis. Podocyte injury or podocyte loss in the renal glomerulus has been proposed as the crucial mechanism in the development of glomerulosclerosis. However, the mechanism by which podocytes respond to injury is poorly understood. TNF and TNF receptor superfamilies are important in the pathogenesis of podocyte injury and apoptosis. The ligand of receptor activator of NF-kappaB (RANKL) and receptor activator of NF-kappaB (RANK) are members of the TNF and receptor superfamilies. We investigated whether RANK-RANKL is a receptor-ligand complex for podocytes responding to injury.
  
  
  RESULTS
  In this study, RANKL and RANK were examined in human podocyte diseases and a rat model of puromycin aminonucleoside nephrosis (PAN). Compared with controls, RANK and RANKL were increased in both human podocyte diseases and the rat PAN model; double immunofluorescence staining revealed that RANK protein expression was mainly attributed to podocytes. Immunoelectron microscopy showed that RANK was localized predominantly at the top of the foot process membrane and the cytoplasm of rat podocyte. In addition, RANK was upregulated in mouse podocytes in vitro after injury induced by puromycin aminonucleoside (PA). Knockdown of RANK expression by small interference RNA (siRNA) exacerbated podocyte apoptosis induced by PA. However, RANKL inhibited significantly the apoptosis of podocytes induced by PA.
  
  
  CONCLUSIONS
  These findings suggest the increase in RANK-RANKL expression is a response to podocyte injury, and RANK-RANKL may be a novel receptor-ligand complex for the survival response during podocyte injury.
authors: Department of Nephrology, Guangdong General Hospital, Guangdong Academy of Medical Sciences, Guangzhou, Guangdong, China.
authors: Shuangxin
authors: S
authors: Liu
authors: Wei
authors: W
authors: Shi
authors: Houqin
authors: H
authors: Xiao
authors: Xinling
authors: X
authors: Liang
authors: Chunyu
authors: C
authors: Deng
authors: Zhiming
authors: Z
authors: Ye
authors: Ping
authors: P
authors: Mei
authors: Suxia
authors: S
authors: Wang
authors: Xiaoying
authors: X
authors: Liu
authors: Zhixin
authors: Z
authors: Shan
authors: Yongzheng
authors: Y
authors: Liang
authors: Bin
authors: B
authors: Zhang
authors: Wenjian
authors: W
authors: Wang
authors: Yanhui
authors: Y
authors: Liu
authors: Lixia
authors: L
authors: Xu
authors: Yunfeng
authors: Y
authors: Xia
authors: Jianchao
authors: J
authors: Ma
authors: Zhilian
authors: Z
authors: Li
mesh_terms: D000818:Animals; D000964:Antimetabolites, Antineoplastic / Q000009:adverse effects / Q000494:pharmacology; D017209:Apoptosis / Q000187:drug effects; D002461:Cell Line, Transformed; D002470:Cell Survival / Q000187:drug effects; D004195:Disease Models, Animal; D005260:Female; D005786:Gene Expression Regulation / Q000187:drug effects; D005923:Glomerulosclerosis, Focal Segmental / Q000378:metabolism* / Q000473:pathology; D006801:Humans; D007678:Kidney Glomerulus / Q000293:injuries* / Q000378:metabolism / Q000473:pathology; D008297:Male; D051379:Mice; D016513:Mice, SCID; D009401:Nephrosis / Q000139:chemically induced / Q000378:metabolism / Q000473:pathology; D050199:Podocytes / Q000378:metabolism* / Q000473:pathology; D011691:Puromycin / Q000009:adverse effects / Q000494:pharmacology; D053245:RANK Ligand / Q000378:metabolism*; D051381:Rats; D053246:Receptor Activator of Nuclear Factor-kappa B / Q000378:metabolism*
chemical_list: D000964:Antimetabolites, Antineoplastic; D053245:RANK Ligand; D053246:Receptor Activator of Nuclear Factor-kappa B; C505686:TNFRSF11A protein, human; C505688:TNFSF11 protein, human; C505687:Tnfrsf11a protein, mouse; C505689:Tnfsf11 protein, mouse; D011691:Puromycin