RRC ID 31848
Author Shimizu H, Bolati D, Adijiang A, Muteliefu G, Enomoto A, Nishijima F, Dateki M, Niwa T.
Title NF-κB plays an important role in indoxyl sulfate-induced cellular senescence, fibrotic gene expression, and inhibition of proliferation in proximal tubular cells.
Journal Am J Physiol Cell Physiol
Abstract We previously demonstrated that indoxyl sulfate induces senescence and dysfunction of proximal tubular cells by activating p53 expression. However, little is known about the role of nuclear factor (NF)-κB in these processes. The present study examines whether activation (phosphorylation) of NF-κB by indoxyl sulfate promotes senescence and dysfunction in human proximal tubular cells (HK-2 cells). Indoxyl sulfate induced phosphorylation of NF-κB p65 on Ser-276, which was suppressed by N-acetylcysteine, an antioxidant. Furthermore, indoxyl sulfate induced NF-κB p65 expression. Inhibitors of NF-κB (pyrrolidine dithiocarbamate and isohelenin) and NF-κB p65 small interfering RNA (siRNA) suppressed indoxyl sulfate-induced senescence-associated β-galactosidase activity and expression of p53, transforming growth factor (TGF)-β1, and α-smoothe muscle actin (SMA). The induction of p53 expression and p53 promoter activity by indoxyl sulfate were inhibited by pifithrin-α, p-nitro, an inhibitor of p53, whereas p53-transfected cells showed enhanced p53 promoter activity. NF-κB inhibitors suppressed indoxyl sulfate-induced p21 expression, whereas NF-κB p65 siRNA enhanced its expression. NF-κB inhibitors partially alleviated indoxyl sulfate-induced inhibition of cellular proliferation. NF-κB p65 siRNA-transfected cells showed less proliferation in the presence of indoxyl sulfate than control cells. Phosphorylated NF-κB p65 was expressed and colocalized with p53, p21, β-galactosidase, TGF-β1, and α-SMA in the kidneys of chronic renal failure (CRF) rats. AST-120, which reduces serum indoxyl sulfate level, suppressed their expression in the CRF rat kidneys. Taken together, NF-κB plays an important role in indoxyl sulfate-induced cellular senescence, fibrotic gene expression, and inhibition of proliferation in proximal tubular cells. More notably, indoxyl sulfate accelerates proximal tubular cell senescence with progression of CRF through reactive oxygen species-NF-κB-p53 pathway.
Volume 301(5)
Pages C1201-12
Published 2011-11-1
DOI 10.1152/ajpcell.00471.2010
PII ajpcell.00471.2010
PMID 21832251
MeSH Actins / metabolism Acute Kidney Injury / drug therapy Acute Kidney Injury / metabolism Animals Benzothiazoles / pharmacology Cell Line Cell Proliferation / drug effects Cellular Senescence / drug effects Cellular Senescence / physiology* Cyclin-Dependent Kinase Inhibitor p21 / metabolism Humans Indican / metabolism* Kidney Tubules, Proximal / drug effects Male NF-kappa B / antagonists & inhibitors NF-kappa B / metabolism* Promoter Regions, Genetic Pyrrolidines / pharmacology RNA, Small Interfering / pharmacology Rats Rats, Sprague-Dawley Sesquiterpenes / pharmacology Thiocarbamates / pharmacology Toluene / analogs & derivatives Toluene / pharmacology Transforming Growth Factor beta1 / metabolism Tumor Suppressor Protein p53 / genetics Tumor Suppressor Protein p53 / metabolism beta-Galactosidase / metabolism
IF 3.485
Times Cited 93
DNA material pNF-kappaB RE-TK hRluc(F) (RDB05576) pGL4-phTP53 (RDB07330) pCMFlag_hsTP53 (RDB06754) pCMV_S-FLAG (RDB05956).