title: Delayed administration of suramin attenuates the progression of renal fibrosis in obstructive nephropathy.
abstract: We recently showed that suramin treatment prevents the onset of renal fibrosis in a model of obstructive nephropathy induced by unilateral ureteral obstruction (UUO). In this study, we further assessed the effect of delayed administration of suramin on the progression of tubulointerstitial fibrosis. Mice were given a single dose of suramin at 20 mg/kg starting at day 3 of obstruction, and kidneys were harvested after an additional 7 or 14 days of obstruction. Suramin completely blocked further increase in expression of type I collagen and fibronectin and largely suppressed expression of α-smooth muscle actin (α-SMA) in both treatment groups. UUO injury induced phosphorylation of Smad-3, a key mediator of transforming growth factor-β (TGF-β) signaling, epidermal growth factor receptor, and platelet-derived growth factor receptor after 3 days and further increased at 10 days after UUO injury. When suramin was administered at 3 days after obstruction, phosphorylation of these molecules was not further increased in the obstructed kidney. Suramin treatment also inhibited activation of signal transducer and activator of transcription 3 and extracellular signal-regulated kinase 1 and 2, two signaling pathways associated with renal fibrogenesis. Furthermore, delayed application of suramin suppressed TGF-β1-induced expression of α-SMA and fibronectin in cultured renal interstitial fibroblasts. These results indicate that administration of suramin is effective in attenuating the progression of renal fibrosis after injury and suggest the potential clinical application of suramin as an antifibrotic treatment in patients with chronic kidney disease.
authors.affiliation: Department of Nephrology, Shanghai East Hospital, Tongji University School of Medicine, Shanghai, China.
authors.forename: Na
authors.initials: N
authors.lastname: Liu
authors.forename: Evelyn
authors.initials: E
authors.lastname: Tolbert
authors.forename: Murugavel
authors.initials: M
authors.lastname: Ponnusamy
authors.forename: Haidong
authors.initials: H
authors.lastname: Yan
authors.forename: Shougang
authors.initials: S
authors.lastname: Zhuang
mesh_terms: D000199:Actins / Q000378:metabolism; D000818:Animals; D015153:Blotting, Western; D002478:Cells, Cultured; D024042:Collagen Type I / Q000096:biosynthesis; D018450:Disease Progression; D066246:ErbB Receptors / Q000096:biosynthesis / Q000235:genetics; D048049:Extracellular Signal-Regulated MAP Kinases / Q000378:metabolism; D005347:Fibroblasts / Q000187:drug effects / Q000378:metabolism; D005353:Fibronectins / Q000096:biosynthesis; D005355:Fibrosis; D007150:Immunohistochemistry; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D009395:Nephritis, Interstitial / Q000188:drug therapy* / Q000209:etiology / Q000473:pathology; D010766:Phosphorylation; D017479:Receptors, Platelet-Derived Growth Factor / Q000096:biosynthesis / Q000235:genetics; D051900:Smad3 Protein / Q000378:metabolism; D013498:Suramin / Q000627:therapeutic use*; D014517:Ureteral Obstruction / Q000150:complications / Q000188:drug therapy* / Q000473:pathology
chemical_list: D000199:Actins; D024042:Collagen Type I; D005353:Fibronectins; D051900:Smad3 Protein; C497791:Smad3 protein, mouse; D013498:Suramin; C541485:EGFR protein, mouse; D066246:ErbB Receptors; D017479:Receptors, Platelet-Derived Growth Factor; D048049:Extracellular Signal-Regulated MAP Kinases