Low-dose paclitaxel ameliorates renal fibrosis in rat UUO model by inhibition of TGF-beta/Smad activity.
Transforming growth factor-beta (TGF-beta) has a pivotal function in the progression of renal fibrosis in a wide variety of renal diseases. Smad proteins have been identified to have an important function in regulating the expression of extracellular matrix (ECM) proteins through TGF-beta signaling pathway. Aberrant TGF-beta/Smad signaling can be modulated by stabilization of microtubules with paclitaxel. In this study, we investigated if paclitaxel can attenuate tubulointerstitial fibrosis in a rat model of unilateral ureteral obstruction (UUO). Rats in groups of six were subjected to UUO and received low-dose intraperitoneal injection of paclitaxel (0.3 mg/kg) twice a week. They were killed at day 7 and 14 after UUO or Sham operation. TGF-beta signaling cascade and status of various ECM proteins were evaluated by RT-PCR, western blotting and immunohistochemical or immunofluorescence staining. The paclitaxel treatment markedly suppressed Smad2 and Smad3 phosphorylation. This was associated with attenuated expression of integrin-linked kinase, collagens I and III, fibronectin (FN) and alpha-smooth muscle actin, and a substantial decrease in renal fibrosis in animals that underwent UUO and received paclitaxel. These data indicate that the low-dose paclitaxel ameliorates renal tubulointerstitial fibrosis by modulating TGF-beta signaling, and thus, the paclitaxel may have some therapeutic value in humans.
Department of Nephrology, Second Xiangya Hospital, Central South University, Changsha, Hunan, PR China.
Dongshan
D
Zhang
Lin
L
Sun
Wang
W
Xian
Fuyou
F
Liu
Guanghui
G
Ling
Li
L
Xiao
Yanhong
Y
Liu
Youmin
Y
Peng
Yoshisuke
Y
Haruna
Yashpal S
YS
Kanwar
D000818:Animals; D005109:Extracellular Matrix / Q000378:metabolism; D007668:Kidney / Q000473:pathology; D008297:Male; D009400:Nephrosclerosis / Q000209:etiology / Q000473:pathology / Q000517:prevention & control*; D017239:Paclitaxel / Q000494:pharmacology / Q000627:therapeutic use*; D051381:Rats; D017208:Rats, Wistar; D015398:Signal Transduction / Q000187:drug effects; D051785:Smad Proteins / Q000037:antagonists & inhibitors*; D016212:Transforming Growth Factor beta / Q000037:antagonists & inhibitors*; D050257:Tubulin Modulators / Q000494:pharmacology / Q000627:therapeutic use*; D014517:Ureteral Obstruction / Q000150:complications
D051785:Smad Proteins; D016212:Transforming Growth Factor beta; D050257:Tubulin Modulators; D017239:Paclitaxel