Astragaloside IV inhibits renal tubulointerstitial fibrosis by blocking TGF-β/Smad signaling pathway in vivo and in vitro.

Astragaloside IV (AS-IV) is a major active ingredient from Radix astragali, which has been considered as a renoprotective agent; however, its molecular mechanisms are unclear. Thus, we designed to investigate the renoprotective effects and mechanisms of AS-IV in rat model of renal fibrosis induced by unilateral ureteral obstruction (UUO) in vivo and TGF-β1-stimulated rat renal fibroblasts (NRK-49F) in vitro. Sprague-Dawley rats were randomly divided into six groups: sham operation, UUO, UUO/AS-IV (3.3, 10, 33 mg·kg(-1)·d(-1)), and UUO/enalapril (4 mg·kg(-1)·d(-1)). Renal function, tubulointerstitial damage index score, extracellular matrix (ECM) deposition, and the expressions of TGF-β1, connective tissue growth factor (CTGF), α-SMA, fibronectin, collagen I, III, Smad2/3, phosphorylated-Smad2/3, and Smad7 were measured. In addition, the expressions of CTGF, α-SMA, fibronectin, collagen I, III, Smad2/3, phosphorylated-Smad2/3, and Smad7 were measured in TGF-β1-stiumlated NRK-49F cell line. AS-IV significantly decreased UUO-induced renal fibrosis and functional impairment, which are associated with inhibition of TGF-β1, CTGF, α-SMA, and collagen matrix expression, and a decrease in serum creatinine and urea nitrogen. The renoprotective effects of AS-IV on fibrosis were associated with up-regulation of Smad7, thereby blocking up-regulations of TGF-β1, CTGF, and α-SMA, and activation of phosphorylated-Smad2/3. These effects were further conformed in NRK-49F cell line stimulated by TGF-β1. Moreover, knockdown of Smad7 gene in NRK-49F cells was able to prevent AS-IV-induced inhibition to Smad2/3 signaling activation, expression of CTGF, α-SMA, and ECM proteins in response to TGF-β1. Renal tubulointerstitial fibrosis was attenuated by treatment with AS-IV, which was closely related to induction of Smad7, thereby inhibiting TGF-β/Smad signaling.

Wang L ，Chi YF ，Yuan ZT ，Zhou WC ，Yin PH ，Zhang XM ，Peng W ，Cai H ... -  《-》

You-gui Pill ameliorates renal tubulointerstitial fibrosis via inhibition of TGF-β/Smad signaling pathway.

You-gui Pill (YGP), a traditional Chinese medicinal prescription, was widely used to warm and recuperate "kidney-yang" clinically for hundreds of years in China. Recent studies found that YGP had a potential benefit for renoprotection. The present study aimed to elucidate the in vivo and in vitro efficacy of YGP on renal tubulointerstitial fibrosis, and the molecular mechanism is also investigated. Rat renal tubulointerstitial fibrosis model was elicited by unilateral ureteral obstruction (UUO). Sprague-Dawley rats underwent UUO and were studied after 14 days. Animals were randomly subjected to six groups: sham, UUO, UUO/YGP (0.14, 0.42, 1.26g/kg/d), and UUO/enalapril (10mg/kg/d). HE, Masson and ELISA were used for evaluate renal injury and function. Immunohistochemical analysis and western blot were used to detect the expressions of α-SMA, fibronectin, collagen matrix and Smads. In vitro studies were investigated in TGF-β1-stiumlated NRK-49F cell line. Oral administration of YGP significantly decreased UUO-induced inflammatory cell infiltration, tubular atrophy and interstitial fibrosis, and there was no significant difference between YGP at 1.26g/kg and enalapril at 10mg/kg treatment (P>0.05). Meanwhile, serum creatinine and blood urea nitrogen levels were reduced dramatically (P<0.01). In coincide with the decreased of TGF-β1, α-SMA, fibronectin and collagen matrix expressions were also declined with YGP treatment in both UUO kidneys and TGF-β1-stimulated NRK-49F cell line. Additionally, nuclear translocation of p-Smad2/3 was markedly down-regulated by YGP (P<0.001), with a relative mild up-regulated expression of Smad7 (P<0.05). Our findings demonstrate that YGP had a renoprotective effect in ameliorating renal tubulointerstitial fibrosis, and this activity possibly via suppression of the TGF-β and its downstream regulatory signaling pathway, including Smad2/3.

Wang L ，Cao AL ，Chi YF ，Ju ZC ，Yin PH ，Zhang XM ，Peng W ... -  《-》

Ureic clearance granule, alleviates renal dysfunction and tubulointerstitial fibrosis by promoting extracellular matrix degradation in renal failure rats, compared with enalapril.

Chinese herbal compound prescription has a unique therapeutic action on chronic kidney disease (CKD) in China. In clinics, Uremic Clearance Granules (UCG), a compounded Chinese patent medicine, has been frequently used to treat chronic renal failure (CRF) patients for nearly 30 years, however, the deep therapeutic mechanisms involved in vivo remain a challenge. This study aims to demonstrate the effects and mechanisms of UCG on renal dysfunction and tubulointerstitial fibrosis by regulating extracellular matrix (ECM) degradation and transforming growth factor (TGF)-beta1/Smad signaling activity in vivo, compared with enalapril. Twenty-six rats were randomly divided into 4 groups, a sham-operated group (Sham group), a vehicle-intervened group (Vehicle group), a UCG-treated group (UCG group) (5g/kg/day) and an enalapril-treated group (Enalapril group) (20mg/kg/day). The rats with renal failure were induced by adenine (150 mg/kg/day) and unilateral ureteral obstruction (UUO), and killed on day 35 after the administration. Proteinuria, urinary N-acetyl-beta-D-glucosaminidase (UNAG), blood biochemical parameters, renal morphological changes, collagen type IV (CIV), matrix metalloproteinase (MMP)-2, MMP-9 and tissue inhibitors of metalloproteinase (TIMP)-1, as well as the key molecular protein expressions in TGF-beta1/Smad signaling pathway were observed, respectively. Adenine administration and UUO induced severe renal damages, as indicated by renal dysfunction, proteinuria and the marked histopathological injuries in the tubules and interstitium, which were associated with MMP-2/TIMP-1 imbalance and TGF-beta1/Smad signaling activity, as shown by up-regulation of the protein expressions of TGF-beta1, TGF-beta receptor type I (RI), TGF-beta receptor type II (RII), Smad2/3, phosphorylated-Smad2/3 (p-Smad2/3) and Smad4, as well as down-regulation of the protein expression of Smad7 in the kidney. UCG treatment, however, significantly not only attenuated renal dysfunction and tubulointerstitial fibrosis, but also improved the protein expressions of MMP-2, TIMP-1, TGF-beta1, TGF-beta RI, p-Smad2/3, Smad4 and Smad7 in the kidney. Besides, the effects of UCG were stronger than those of enalapril partly. UCG similar to enalapril, is renoprotective via ameliorating renal dysfunction and tubulointerstitial fibrosis in the renal failure model. The potential mechanisms by which UCG exerts its therapeutical effects in vivo are through promoting ECM degradation and regulating MMP-2/TIMP-1 balance or signaling molecular activity in TGF-beta1/Smad pathway in the kidney. These findings suggest that UCG treatment is undoubtedly useful in preventing the progression of CRF.

Huang YR ，Wei QX ，Wan YG ，Sun W ，Mao ZM ，Chen HL ，Meng XJ ，Shi XM ，Tu Y ，Zhu Q ... -  《-》

[Effects of Chinese herbal medicine Yiqi Huoxue Formula on TGF-β/smad signal transduction pathway and connective tissue growth factor in rats with renal interstitial fibrosis].

Liu YM ，Liu RH ，Liu WJ ，Liu L ，Wu ZK ，Chen YY ... -  《-》

Fluorofenidone attenuates tubulointerstitial fibrosis by inhibiting TGF-β(1)-induced fibroblast activation.

Novel therapeutic agents are urgently needed to combat renal fibrosis. The purpose of this study was to assess, using complete unilateral ureteral obstruction (UUO) in rats, whether fluorofenidone (AKF-PD) [1-(3-fluorophenyl)-5-methyl-2-(1H)-pyridone] inhibits renal fibrosis, and to determine whether it exerts its inhibitory function on renal fibroblast activation. Sprague-Dawley rats were randomly divided into 3 groups: sham operation, UUO and UUO/AKF-PD (500 mg/kg/day). Renal function, tubulointerstitium damage index score, extracellular matrix (ECM) deposition, and the expressions of TGF-β(1), collagen III, α-SMA, p-Smad2, p-Smad3, p-ERK1/2, p-JNK and p-p38 were measured. In addition, the expressions of α-SMA, fibronectin, CTGF, p-Smad2/3, p-ERK1/2, p-p38 and p-JNK were measured in TGF-β(1)-stimulated normal rat renal fibroblasts (NRK-49F). AKF-PD treatment significantly attenuated tubulointerstitium damage, ECM deposition, the expressions of TGF-β(1), collagen III, α-SMA, p-ERK1/2, p-p38 and p-JNK in vivo. In vitro, AKF-PD dose-dependently inhibited expressions of α-SMA, fibronectin and CTGF. Furthermore, AKF-PD did not inhibit Smad2/3 phosphorylation or nuclear accumulation, but rather attenuated ERK, p38 and JNK activation. AKF-PD treatment inhibits the progression of renal interstitial fibrosis in obstructed kidneys; this is potentially achieved by suppressing fibroblast activation. Therefore, AKF-PD is a special candidate for the treatment of renal fibrosis.

Yuan Q ，Wang R ，Peng Y ，Fu X ，Wang W ，Wang L ，Zhang F ，Peng Z ，Ning W ，Hu G ，Wang Z ，Tao L ... -  《-》