PURPOSE: To review the recent developments in the structure and function of Smad proteins. DATA SOURCES: Both Chinese- and English-language literatures were searched using MEDLINE/CD-ROM (1997 - 2000) and the Index of...PURPOSE: To review the recent developments in the structure and function of Smad proteins. DATA SOURCES: Both Chinese- and English-language literatures were searched using MEDLINE/CD-ROM (1997 - 2000) and the Index of Chinese-Language Literature (1997 - 2000). STUDY SELECTION: Data from published articles about TGF-beta signal transduction in recent domestic and foreign literature were selected. DATA EXTRACTION: Data were mainly extracted from 22 articles which are listed in the reference section of this review. RESULTS: Smad proteins mediate signal transduction induced by the TGF-beta superfamily. Based on their structural and functional properties, Smad proteins are divided into three groups. The first group, receptor-regulated Smads (R-Smads), are phosphorylated by activated type I receptors and form heteromeric complexes with the second group of Smads, common mediator Smads (Co-Smads). These Smad complexes translocate into the nucleus to influence gene transcription. Inhibitory Smads (I-Smads) are the third group and these antagonize the activity of R-Smads. In the nucleus, Smads can directly contact Smad-binding elements (SBE) in target gene promoters. Through interaction with different transcription factors, transcriptional co-activators or co-repressors, Smads elicit different effects in various cell types. The aberrance of Smad proteins has been noted in several human disorders such as fibrosis, hypertrophic scarring and cancer. CONCLUSION: The structure of Smads determines their function as transcriptional factors which translocate signals from the cell surface to the nucleus where Smads regulate TGF-beta superfamily-dependent gene expression.展开更多
Sm ad蛋白直接参与转化生长因子 (TGF-β)、骨形态发生蛋白 (BMP)和活化素的信号传导 ,TGF-β和 BMP是调节骨代谢的信息转导是由 Sm ad蛋白家族成员承担的。在已经鉴定的 8种 Sm ads成员中 ,与骨代谢密切相关的是 Sm ad 1、Sm ad 5及 Sm...Sm ad蛋白直接参与转化生长因子 (TGF-β)、骨形态发生蛋白 (BMP)和活化素的信号传导 ,TGF-β和 BMP是调节骨代谢的信息转导是由 Sm ad蛋白家族成员承担的。在已经鉴定的 8种 Sm ads成员中 ,与骨代谢密切相关的是 Sm ad 1、Sm ad 5及 Smad 4。实验证明在成骨细胞系 Sm ad是 BMP信号转导的关键因子 ,对 Smad蛋白家族的了解将有助于对 TGF-β和展开更多
OBJECTIVE: To investigate the effect of Banxia Xiexin decoction(BXD) on Helicobacter pylori(Hp)-related peptic ulcers(PUs) and the possible mecha-nism underlying BXD actions via the transforming growth factor-β/small...OBJECTIVE: To investigate the effect of Banxia Xiexin decoction(BXD) on Helicobacter pylori(Hp)-related peptic ulcers(PUs) and the possible mecha-nism underlying BXD actions via the transforming growth factor-β/small mothers against decapentaplegic(TGF-β/Smad) signaling pathway.METHODS: PU patients with cold-heat complex syndrome were randomly assigned to groups that received Chinese or Western medicines with 20 patients in each group. Serum was collected after 7 d of treatment. The healthy group included 20 individuals. Gastric mucosal epithelial cell line GES-1 was cultured in vitro and randomly divided into the following seven groups: control, model, healthy,Western Medicine, prior treatment, low dosage,and high dosage. After 72 h of treatment with the corresponding serum, the m RNA and protein expression levels of TGF-β1, Smad3, and Smad7 were measured by reverse transcription quantitative polymerase chain reaction and western blotting, respectively.RESULTS: The m RNA expression levels of TGF-β1 and Smad3 in GES-1 cells were increased after Hp introduction, and these increased levels were reduced by the BXD-containing serum. The protein levels of p-Smad3, but not TGF-β1 or Smad3, were significantly increased in Hp-treated GES-1 cells,and treatment with the BXD-containing serum markedly decreased the protein levels. Smad7 expression was significantly enhanced following treatment with the BXD-containing serum at transcriptional and protein levels in a dose-dependent manner.CONCLUSION: BXD regulates the TGF-β/Smad signaling pathway by inhibiting the expression of TGF-β1 and Smad3, and increasing the expression of Smad7.展开更多
基金supported by a grant from the National Natural Science Foundation of China(No．G1999054204)； the National Prominent Youth Science Foundation of China(No．39525024)．
文摘PURPOSE: To review the recent developments in the structure and function of Smad proteins. DATA SOURCES: Both Chinese- and English-language literatures were searched using MEDLINE/CD-ROM (1997 - 2000) and the Index of Chinese-Language Literature (1997 - 2000). STUDY SELECTION: Data from published articles about TGF-beta signal transduction in recent domestic and foreign literature were selected. DATA EXTRACTION: Data were mainly extracted from 22 articles which are listed in the reference section of this review. RESULTS: Smad proteins mediate signal transduction induced by the TGF-beta superfamily. Based on their structural and functional properties, Smad proteins are divided into three groups. The first group, receptor-regulated Smads (R-Smads), are phosphorylated by activated type I receptors and form heteromeric complexes with the second group of Smads, common mediator Smads (Co-Smads). These Smad complexes translocate into the nucleus to influence gene transcription. Inhibitory Smads (I-Smads) are the third group and these antagonize the activity of R-Smads. In the nucleus, Smads can directly contact Smad-binding elements (SBE) in target gene promoters. Through interaction with different transcription factors, transcriptional co-activators or co-repressors, Smads elicit different effects in various cell types. The aberrance of Smad proteins has been noted in several human disorders such as fibrosis, hypertrophic scarring and cancer. CONCLUSION: The structure of Smads determines their function as transcriptional factors which translocate signals from the cell surface to the nucleus where Smads regulate TGF-beta superfamily-dependent gene expression.
文摘Sm ad蛋白直接参与转化生长因子 (TGF-β)、骨形态发生蛋白 (BMP)和活化素的信号传导 ,TGF-β和 BMP是调节骨代谢的信息转导是由 Sm ad蛋白家族成员承担的。在已经鉴定的 8种 Sm ads成员中 ,与骨代谢密切相关的是 Sm ad 1、Sm ad 5及 Smad 4。实验证明在成骨细胞系 Sm ad是 BMP信号转导的关键因子 ,对 Smad蛋白家族的了解将有助于对 TGF-β和
基金Supported by the National Natural Science Foundation of China(Intervention of Serum with Banxia Xiexin Decoction in Human Gastric Epithelial Cells Co-cultured with Helicobacter pylori in vitro Based on the TGF-β/Smad Signaling Pathway and Epigenetics,No.81403331Research on the Mechanism of Compound Prescription of Chinese Traditional Medicine Regulating the Endocannabinoid System in Non-alcoholic Steatohepatitis,No.81503529+2 种基金Mechanism of Chlorogenic Acid and Geniposide in NASH by Regulating Kupffer Cell Polarization Based on the Gut-liver Axis,No.81673660)the Natural Science Foundation of Fujian Province(Intervention of Serum with Soothing Liver and Invigorating Spleen Recipe in Hep G2.2.15 Cells via the JAK2-STAT3Signaling Pathway,No.2014J01363)the Pilot Project of Science and Technology of Fujian Province(Study of Compound Prescription of Chinese Traditional Medicine for Fibrosis Based on the Endocannabinoid System,No.2016D012)
文摘OBJECTIVE: To investigate the effect of Banxia Xiexin decoction(BXD) on Helicobacter pylori(Hp)-related peptic ulcers(PUs) and the possible mecha-nism underlying BXD actions via the transforming growth factor-β/small mothers against decapentaplegic(TGF-β/Smad) signaling pathway.METHODS: PU patients with cold-heat complex syndrome were randomly assigned to groups that received Chinese or Western medicines with 20 patients in each group. Serum was collected after 7 d of treatment. The healthy group included 20 individuals. Gastric mucosal epithelial cell line GES-1 was cultured in vitro and randomly divided into the following seven groups: control, model, healthy,Western Medicine, prior treatment, low dosage,and high dosage. After 72 h of treatment with the corresponding serum, the m RNA and protein expression levels of TGF-β1, Smad3, and Smad7 were measured by reverse transcription quantitative polymerase chain reaction and western blotting, respectively.RESULTS: The m RNA expression levels of TGF-β1 and Smad3 in GES-1 cells were increased after Hp introduction, and these increased levels were reduced by the BXD-containing serum. The protein levels of p-Smad3, but not TGF-β1 or Smad3, were significantly increased in Hp-treated GES-1 cells,and treatment with the BXD-containing serum markedly decreased the protein levels. Smad7 expression was significantly enhanced following treatment with the BXD-containing serum at transcriptional and protein levels in a dose-dependent manner.CONCLUSION: BXD regulates the TGF-β/Smad signaling pathway by inhibiting the expression of TGF-β1 and Smad3, and increasing the expression of Smad7.
