Resveratrol inhibits the expression of typeⅠ and type Ⅲ collagen induced by AngⅡ in cardiac fibroblasts through regulating the TGF-β1/Smad3 signaling pathway / 西安交通大学学报(医学版)

Objective To explore the inhibitory effect of resveratrol on hypertension-related myocardial fibrosis and the key role of TNF-β/Smads signaling pathway in the anti-fibrosis of resveratrol.Methods The expression of vimentin in the primary rat CFs was evaluated by immunofluorescence to determine the cell type.CFs were treated in different conditions,the mRNA expression levels of type Ⅰ and type Ⅲ collagen and TGF-β1 were detected by Real-time PCR;the protein expression levels of type Ⅰ and type Ⅲ collagen,TGF-β1 ,Smad-3 and P-Smad-3 were detected by Western blot.The secretion levels of type Ⅰ collagen and TGF-β1 in CFs supernatant were measured by ELISA assay.Results Rat CFs were successfully extracted,and vimentin expression was obvious. Real-time PCR results indicated that the gene expression levels of collagen Ⅰ and Ⅲ and TGF-β1 in CFs by exposure to AngⅡ were significantly increased as compared with those in normal group (P＜0.05).However,AngⅡ-induced collagen Ⅰ and Ⅲ and TGF-β1 mRNA upregulation was inhibited by Res treatment (P＜0.05).Western blot analysis showed that the protein expressions of collagen Ⅰ and Ⅲ and TGF-β1 in CFs were also increased after exposed to AngⅡ when compared to the normal controls (P＜0.05).Similarly,AngⅡ-mediated collagen Ⅰ and Ⅲand TGF-β1 upregulation was prevented by Res treatment (P＜0.05).In addition,the phosphorylation level of Smad-3 was enhanced by both interventions (P＜0.05).However,AngⅡ stimulated TGF-β1 upregulation while Smad-3 phosphorylation was suppressed by Res treatment (P＜0.05).The secretion levels of collagen Ⅰ and TGF-β1 in CFs supernatant increased significantly in CFs exposed to AngⅡ condition as compared with those in normal condition (P＜0.05).However,AngⅡ increased collagen Ⅰ and TGF-β1 secretion was prevented by Res intervention (P＜0.05).Conclusion Resveratrol inhibits the expressions of type Ⅰ and type Ⅲ collagen induced by AngⅡ in cardiac fibroblasts through regulating the TGF-β1/Smad3 signaling pathway.

Smads as therapeutic targets for chronic kidney disease

Renal fibrosis is a hallmark of chronic kidney disease (CKD). It is generally thought that transforming growth factor-beta1 (TGF-beta1) is a key mediator of fibrosis and mediates renal scarring positively by Smad2 and Smad3, but negatively by Smad7. Our recent studies found that in CKD, TGF-beta1 is not a sole molecule to activate Smads. Many mediators such as angiotensin II and advanced glycation end products can also activate Smads via both TGF-beta-dependent and independent mechanisms. In addition, Smads can interact with other signaling pathways, such as the mitogen-activated protein kinase and nuclear factor-kappaB (NF-kappaB) pathways, to regulate renal inflammation and fibrosis. In CKD, Smad2 and Smad3 are highly activated, while Smad7 is reduced or lost. In the context of fibrosis, Smad3 is pathogenic and mediates renal fibrosis by upregulating miR-21 and miR-192, but down-regulating miR-29 and miR-200 families. By contrast, Smad2 and Smad7 are protective. Overexpression of Smad7 inhibits both Smad3-mediated renal fibrosis and NF-kappaB-driven renal inflammation. Interestingly, Smad4 has diverse roles in renal fibrosis and inflammation. The complexity and distinct roles of individual Smads in CKD suggest that treatment of CKD should aim to correct the imbalance of Smad signaling or target the Smad3-dependent genes related to fibrosis, rather than to block the general effect of TGF-beta1. Thus, treatment of CKD by overexpression of Smad7 or targeting Smad3-dependent miRNAs such as downregulation of miR-21 or overexpression of miR-29 may represent novel therapeutic strategies for CKD.

Expression and mutational analysis of TGF-beta/Smads signaling in human cervical cancers / 부인종양

OBJECTIVE: To define the molecular basis of TGF-beta1 function in cervical carcinogenesis, we explored the expression and mutational status of TGF-beta1, TGF-beta1 receptors, and Smads, the regulators of the TGF-beta1 signaling pathway, in human cervical cancers. METHODS: Expression of TGF-beta1, TGF-beta1 receptors, and Smads transcripts were determined by quantitative reverse transcription-polymerase chain reaction (RT-PCR), and sequence alteration was analyzed using RT-PCR-single-strand conformation polymorphism (SSCP) analysis. Genomic levels of TGF-beta1, TGF-beta1 receptors and Smads was also measured by quantitative genomic PCR. RESULTS: Abnormal overexpression of TGF-beta1 and abnormal reduction of type II TGF-beta1 receptor were identified in 36% (18 of 50) and 20% (10 of 50) of cervical cancer tissues, respectively. 22% (11 of 50) in Smad2 and 14% (7 of 50) in Smad4 revealed tumor specific mRNA reduction less than a half of normal means. In addition, no evidence for sequence alterations of the gene was found by RT-PCR-SSCP analysis. CONCLUSION: Our study demonstrates that disruption of TGF-beta/Smad signaling pathway exist in human cervical cancer, suggesting that abnormal expressions of the member of TGF-beta/Smad signaling pathway might contribute to the malignant progression of human cervical tumors via suppressing the tumor suppression function of TGF-beta1 1's tumor suppression function.