Tumorigenesis and cancer progression are closely associated with the transforming growth factor-beta (TGF-beta) and its downstream component Smad. The TGF-beta/Smad signaling pathway, which is activated in prostate cancer, has a regulatory effect on cell adhesion, the actin filament system and cell cycle, as well as the expression of specific genes. Meanwhile, other protein signals such as MAPK and PI3K/Akt/mTOR and some genes may act on the expression of the TGF-beta/Smad pathway. This article updates recent researches on the expression, action and regulatory effect of the TGF-beta/Smad signaling pathway in prostate cancer.
Humans ; Male ; Prostatic Neoplasms ; metabolism ; Signal Transduction ; Smad Proteins ; metabolism ; Transforming Growth Factor beta ; metabolism

Cardiovascular Diseases ; metabolism ; pathology ; Humans ; Smad Proteins ; metabolism ; Trans-Activators ; metabolism

Bone morphogenetic proteins (BMPs) belong to TGF-β superfamily and are a group of important cytokines involved in cell differentiation, proliferation and embryonic development. Multiple BMPs play important roles in several functions of vertebrates. Signaling pathway of BMPs is known to be mediated by Smad proteins, which include 8 members while Smad1, Smad5 and Smad8 are involved in BMPs signal transduction while Smad2 and Smad3 are mediated TGF-β signal transduction. Although several BMPs such as BMP4 and BMP9 have been documented in the liver, BMP13 has not been examined in the liver. BMP13 also known as growth differentiation factor (GDF)-6 or cartilage-derived morphogenetic protein (CDMP)-2 is one of the BMPs family members. Function of BMP13 has been investigated in bone and tendon repair. It can stimulate tendon-like cell proliferation. However, our recent findings revealed that there was expression of BMP13 in the liver and its expression was modulated during metabolic disorders. The current article is to understand biological function of BMP13 especially in the liver.
Bone Morphogenetic Proteins ; metabolism ; physiology ; Growth Differentiation Factor 6 ; metabolism ; physiology ; Humans ; Liver ; metabolism ; Liver Diseases ; metabolism ; Smad Proteins ; metabolism

OBJECTIVE: The purpose of this study is to investigate the potential effects of sclerostin (SOST) on the biological funtions and related mechanisms of cementoblasts under mechanical stress. METHODS: OCCM-30 cells were treated with varying doses of SOST (0, 25, 50, and 100 ng·mL⁻¹) and were loaded with uniaxial compressive stress (2 000 μ strain with a frequency of 0.5 Hz) for six hours. Western blot was utilized to detect the expressions of β-catenin, p-smad1/5/8, and smad1/5/8 proteins. Alkaline phosphatase (ALP) activity was determined, and reverse transcription polymerase chain reaction was used to measure the expressions of runt-related transcription factor 2 (Runx-2), osteocalcin (OCN), bone sialoproteins (BSP), receptor activator of NF-κB ligand (RANKL) and osteoprotegerin (OPG) mRNA. RESULTS: The expression of p-smad
1/5/8 was significantly downregulated with increasing SOST. β-catenin and smad1/5/8 exhibited no difference. ALP activity decreased under mechanical compressive stress with increasing SOST concentrations. Runx-2 expression was reduced with increasing SOST concentrations, and a similar trend was observed for the BSP and OCN expressions. When the SOST concentration was enhanced, RANKL expression gradually increased, whereas the expression of OPG decreased. CONCLUSIONS Under mechanical comprehensive stress, SOST can adjust the bone morphogenetic protein (BMP) /smad signal pathway. Osteosclerosis inhibits the mineralization of cementoblasts under mechanical compressive stress, which may be achieved by inhibiting the expressions of osteogenesis factors (Runx2, OCN, BSP, and others) and by promoting the ratio of cementoclast-related factors (RANKL/OPG) through BMP signal pathways.
Bone Morphogenetic Proteins ; metabolism ; Core Binding Factor Alpha 1 Subunit ; Dental Cementum ; Osteocalcin ; Smad Proteins ; metabolism ; Stress, Mechanical

Humans ; Liver Cirrhosis ; metabolism ; RNA, Messenger ; genetics ; Signal Transduction ; Smad Proteins ; metabolism ; Transforming Growth Factor beta1 ; metabolism

Animals ; Humans ; Liver Cirrhosis ; metabolism ; Signal Transduction ; Smad Proteins ; metabolism ; physiology ; Transforming Growth Factor beta ; metabolism ; physiology

Animals ; Liver ; metabolism ; Liver Regeneration ; Male ; Rats ; Rats, Wistar ; Smad Proteins ; metabolism ; p38 Mitogen-Activated Protein Kinases ; metabolism

OBJECTIVESTo investigate the role of glycyrrhizin on TGFbeta1 stimulated signaling transduction in rat hepatic stellate cells (HSCs).

METHODSThe mice HSCs were isolated and cultured with or without glycyrrhizin (1 micromol/L-1000 micromol/L) in vitro after TGFbeta1 stimulation. The mRNA level of Smad2, 3, 7 were measured with RT-PCR; protein expression level of Smad2, 3, 7 and collagen I, III were analyzed with Western blot.

RESULTSTGFbeta1 increased the mRNA level and protein expression of Smad2, 3, 7 in HSC; it also increased protein expression of collagen I and III. 1 micromol/L-1000 micromol/L glycyrrhizin decreased the mRNA level and protein expression of Smad2, 3, 7; it also inhibited protein expression of collagen I and III gradually.

CONCLUSIONInterventing the TGFbeta signaling pathway and decreasing the synthesis of collagen, might be involved in the anti-fibrosis mechanism of glycyrrhizin.

Animals ; Glycyrrhizic Acid ; pharmacology ; Hepatocytes ; metabolism ; Male ; Rats ; Signal Transduction ; Smad Proteins ; metabolism ; Transforming Growth Factor beta ; pharmacology

OBJECTIVETo investigate the changes in Smad 2, 3, 4 and 7 of the transforming growth factor-beta 1 (TGF-b1)/Smad signaling pathways in carbon tetrachloride (CCL4)-induced hepatic fibrosis rats treated with TGF-b1 small interfering (si)RNA.

METHODSRats were randomly divided among five groups: non-fibrotic (normal); fibrosis-induced (model); fibrotic treated with 0.125 mg/kg TGF-b1 siRNA; fibrotic treated with 0.250 mg/kg TGF-b1 siRNA; and fibrotic treated with negative control TGF-b1 siRNA. The expression of Smad 2, 3, 4 and 7 was detected by real-time polymerase chain reaction (for mRNA), immunohistochemistry and Western blotting (for protein).

RESULTSThe mRNA and protein levels of Smad 2, 3 and 4 were significantly lower in the the fibrotic rats treated with either 0.250 mg/kg or 0.125 mg/kg TGF-b1 siRNA than in the fibrotic model or the negative control TGF-b1 siRNA rats (P less than 0.01). Moreover, the mRNA and protein expression levels of Smad 2, 3 and 4 were significantly lower in the 0.250 mg/kg TGF-b1 siRNA group than in the 0.125 mg/kg group (P less than 0.05). Comparing the 0.250 mg/kg and 0.125 mg/kg TGF-b1 siRNA groups to the model group and the TGF-b1 siRNA negative control group showed significantly increased levels of mRNA and protein expression of Smad 7 (P less than 0.01). In addition, the expression levels of Smad 7 were significantly higher in the 0.250 mg/kg TGF-b1 siRNA group than in the 0.125 mg/kg group (P less than 0.05).

CONCLUSIONsiRNA-mediated silencing of TGF-b1 in rats led to significantly reduced expression of Smad 2, 3 and 4, but significantly increased expression of Smad 7. TGF-b1 regulation of Smad signaling molecules may contribute to hepatic fibrosis in rats and represent a target of future therapeutic intervention.

Animals ; Gene Silencing ; Liver Cirrhosis ; metabolism ; RNA, Small Interfering ; Rats ; Smad Proteins ; metabolism ; Transforming Growth Factor beta1 ; genetics

OBJECTIVETo elucidate the effects of interferon-gamma (IFN-gamma) on the transforming growth factor beta (TGF-beta)/Smad pathway in keloid-derived fibroblasts (KFb), and to investigate the underlying mechanism in the treatment of pathologic scar with IFN-gamma.

METHODSKeloid tissue of 3 patients were obtained, and then KFb were separated and cultured in vitro. KFb from passages 3 to 5 were used for the study. (1) KFb were divided into control group (incubated with serum-free DMEM), TGF-beta(1) group (treated with 10 ng/mL TGF-beta(1)), IFN-gamma group (treated with 100 ng/mL IFN-gamma), and TGF-beta(1)+IFN-gamma group (incubated with 10 ng/mL TGF-beta(1) combined with 100 ng/mL IFN-gamma). The expression level of mRNA and protein of connective tissue growth factor (CTGF), alpha smooth muscle actin (alpha-SMA) protein and expression of alpha-SMA positive KFb were detected by real-time fluorescent quantitation RT-PCR (FQ-RT-PCR), Western blot and immunofluorescence cytochemical staining. (2) Another sample of KFb was obtained and treated with 10 ng/mL IFN-gamma. The expression level of Smad 3 and Smad 7 protein was detected by Western blot before and 1, 2, 4, 6, 8 h post stimulation (PSH). The expression level of Smad 3 and Smad 7 mRNA was assessed by FQ-RT-PCR before stimulation and 30 mins post stimulation and at PSH, 1, 2, 4, 6, 8. (3) Another sample of KFb was obtained and divided into 1, 10 and 100 ng/mL IFN-gamma groups based on the concentration of IFN-gamma, treated for 4 hours; KFb without IFN-gamma treatment was set up as control group. The expression levels of the protein and mRNA of Smad 3 and Smad 7 were measured by FQ-RT-PCR and Western blot.

RESULTS(1) The level of mRNA and protein of CTGF in IFN-gamma group (0.017 +/- 0.009 and 1.198 +/- 0.004) was respectively lower than that in control group (0.024 +/- 0.013 and 1.229 +/- 0.011, P < 0.05). The level of mRNA and protein of CTGF in TGF-beta(1)+IFN-gamma group (0.634 +/- 0.138 and 1.204 +/- 0.010) was respectively lower than that in TGF-beta(1) group (1.331 +/- 0.298 and 1.727 +/- 0.004, P < 0.01). The fluorescence intensity of alpha-SMA positive KFb (0.922 +/- 0.059) and the expression level of alpha-SMA protein (0.3051 +/- 0.0031) in IFN-gamma group decreased significantly than those in control group (1.055 +/- 0.005 and 0.4513 +/- 0.0094, P < 0.01). The fluorescence intensity of alpha-SMA positive KFb (1.129 +/- 0.004) and the expression level of alpha-SMA protein (0.6734 +/- 0.0098) in TGF-beta(1)+IFN-gamma group decreased significantly than those in TGF-beta(1) group (1.270 +/- 0.005 and 1.3842 +/- 0.0024, P < 0.01). (2) The expression level of Smad 3 mRNA and protein at the first time point after IFN-gamma treatment increased temporarily then decreased gradually, and mRNA expression level reached the nadir at PSH 4, it rose gradually later, though it was still lower at PSH 8 than that before treatment (P < 0.01); protein expression level at PSH 8 was significantly lower than that before treatment (P < 0.01). The expression level of Smad 7 mRNA and protein increased gradually to the maximum at PSH 2 and 4 respectively, then decreased but was still higher at PSH 8 than that before treatment (P < 0.05). (3) Compared with those in control group, the expression levels of Smad 3 mRNA and protein in 1, 10 and 100 ng/mL IFN-gamma group were significantly lower, the expression levels of Smad 7 mRNA and protein were significantly higher (P < 0.05 or P < 0.01). The higher concentration of IFN-gamma, the more significant differences were observed.

CONCLUSIONSIFN-gamma can down-regulate the expression of Smad 3 while up-regulate the expression of Smad 7 in a time- and dose-dependent manner, and reduce the expression level of CTGF and alpha-SMA in the basic state or induced by TGF-beta(1), which shows a significant inhibitory effect on the TGF-beta/Smad signal pathway. This may be an important mechanism in the treatment of pathologic scar by IFN-gamma.

Cells, Cultured ; Fibroblasts ; drug effects ; metabolism ; Humans ; Interferon-gamma ; pharmacology ; Keloid ; metabolism ; RNA, Messenger ; genetics ; Signal Transduction ; drug effects ; Smad Proteins ; metabolism ; Transforming Growth Factor beta1 ; metabolism