PubMed:12675842 JSONTXT

{"project":"PubmedHPO","denotations":[{"id":"T1","span":{"begin":203,"end":224},"obj":"HP_0003774"},{"id":"T2","span":{"begin":211,"end":224},"obj":"HP_0000083"},{"id":"T3","span":{"begin":515,"end":542},"obj":"HP_0005576"}],"text":"Uremic toxins of organic anions up-regulate PAI-1 expression by induction of NF-kappaB and free radical in proximal tubular cells.\nBACKGROUND: Uremic toxins have been suggested to promote progression of chronic renal failure. We have shown that organic anion transporter-mediated uptake of uremic toxins induces oxidative stress in opossum kidney renal tubular cells overexpressing the transporter. Plasminogen activator inhibitor-1 (PAI-1) and nuclear factor-kappa B (NF-kappaB) are major factors known to promote tubulointerstitial fibrosis. The present study examined the signaling pathway that is activated by uremic toxins to induce PAI-1 and activate NF-kappaB in human renal proximal tubular cells (HK-2).\nMETHODS: Uremic toxins in the form of organic anion were examined their ability to induce oxidative stress, PAI-1 gene expression, and NF-kappaB activation in HK-2. PAI-1 expression was measured by enzyme-linked immunosorbent assay (ELISA) and the Northern blotting. Human PAI-1 promoter activity was estimated by luciferase reporter gene (NKkappaB-luc) assay. NF-kappaB activation was measured by the pNFkappaB-luc reporter gene and electrophretic gel mobility shift assay.\nRESULTS: Among organic anion species tested, indoxyl sulfate and indoleacetic acid induced free radical production in HK-2. A nonspecific transporter inhibitor (probenecid) suppressed the IS-stimulated radical production. Indoxyl sulfate and indoleacetic acid dose dependently increased the expressions of PAI-1 mRNA and protein in these cells. The luciferase reporter gene assay revealed that indoxyl sulfate and indoleacetic acid dose dependently activated NF-kappaB and PAI-1 promoter. Activation of NF-kappaB was also confirmed by an electrophoretic gel mobility shift assay. Both antioxidant and NF-kappaB inhibitors dose dependently inhibited the activation of PAI-1 promoter by indoxyl sulfate.\nCONCLUSION: Uremic toxins induce free radical production by renal tubular cells and activate NF-kappaB which, in turn, up-regulates PAI-1 expression. Thus, progression of chronic renal failure may be promoted by PAI-1 up-regulation induced by uremic toxins."}

{"project":"DisGeNET5_gene_disease","denotations":[{"id":"12675842-16#62#67#gene5054","span":{"begin":2102,"end":2107},"obj":"gene5054"},{"id":"12675842-16#21#42#diseaseC0022661","span":{"begin":2061,"end":2082},"obj":"diseaseC0022661"},{"id":"12675842-16#21#42#diseaseC1561643","span":{"begin":2061,"end":2082},"obj":"diseaseC1561643"},{"id":"12675842-16#21#42#diseaseC2316810","span":{"begin":2061,"end":2082},"obj":"diseaseC2316810"}],"relations":[{"id":"62#67#gene505421#42#diseaseC0022661","pred":"associated_with","subj":"12675842-16#62#67#gene5054","obj":"12675842-16#21#42#diseaseC0022661"},{"id":"62#67#gene505421#42#diseaseC1561643","pred":"associated_with","subj":"12675842-16#62#67#gene5054","obj":"12675842-16#21#42#diseaseC1561643"},{"id":"62#67#gene505421#42#diseaseC2316810","pred":"associated_with","subj":"12675842-16#62#67#gene5054","obj":"12675842-16#21#42#diseaseC2316810"}],"text":"Uremic toxins of organic anions up-regulate PAI-1 expression by induction of NF-kappaB and free radical in proximal tubular cells.\nBACKGROUND: Uremic toxins have been suggested to promote progression of chronic renal failure. We have shown that organic anion transporter-mediated uptake of uremic toxins induces oxidative stress in opossum kidney renal tubular cells overexpressing the transporter. Plasminogen activator inhibitor-1 (PAI-1) and nuclear factor-kappa B (NF-kappaB) are major factors known to promote tubulointerstitial fibrosis. The present study examined the signaling pathway that is activated by uremic toxins to induce PAI-1 and activate NF-kappaB in human renal proximal tubular cells (HK-2).\nMETHODS: Uremic toxins in the form of organic anion were examined their ability to induce oxidative stress, PAI-1 gene expression, and NF-kappaB activation in HK-2. PAI-1 expression was measured by enzyme-linked immunosorbent assay (ELISA) and the Northern blotting. Human PAI-1 promoter activity was estimated by luciferase reporter gene (NKkappaB-luc) assay. NF-kappaB activation was measured by the pNFkappaB-luc reporter gene and electrophretic gel mobility shift assay.\nRESULTS: Among organic anion species tested, indoxyl sulfate and indoleacetic acid induced free radical production in HK-2. A nonspecific transporter inhibitor (probenecid) suppressed the IS-stimulated radical production. Indoxyl sulfate and indoleacetic acid dose dependently increased the expressions of PAI-1 mRNA and protein in these cells. The luciferase reporter gene assay revealed that indoxyl sulfate and indoleacetic acid dose dependently activated NF-kappaB and PAI-1 promoter. Activation of NF-kappaB was also confirmed by an electrophoretic gel mobility shift assay. Both antioxidant and NF-kappaB inhibitors dose dependently inhibited the activation of PAI-1 promoter by indoxyl sulfate.\nCONCLUSION: Uremic toxins induce free radical production by renal tubular cells and activate NF-kappaB which, in turn, up-regulates PAI-1 expression. Thus, progression of chronic renal failure may be promoted by PAI-1 up-regulation induced by uremic toxins."}