BACKGROUND: Follicular lymphomas present with various immunohistologic patterns. The immunohistochemical markers used in the diagnosis of follicular lymphoma show variable degrees of sensitivity and specificity, and thus, additional germinal center markers are required. Smad1 has been reported to be overexpressed in follicular lymphoma, but little is known regarding the expression patterns of Smad proteins in human lymphoid tissue. METHODS: In the present study, we performed immunohistochemistry for traditional germinal center markers and for Smad1 in human reactive lymphoid and follicular lymphoma tissues to investigate Smad1's usefulness in the diagnosis of follicular lymphoma. RESULTS: In the reactive germinal centers, most cells were positive for Smad1. Among the 27 follicular lymphoma cases, 17 of 21 (80%) were Smad1 positive, 17 of 27 (63%) were positive for CD10, and 23 of 27 (85%) were positive for Bcl6. Notably, three cases expressed CD10 only, and one only expressed Bcl6. All these cases were grade 3 tumors and showed follicular and diffuse growth patterns. CONCLUSIONS: These results indicate that Smad1 is a candidate as a germinal center marker. Furthermore, they suggest that the Smad signaling pathway might be involved in follicular lymphoma.
Diagnosis ; Germinal Center ; Humans ; Immunohistochemistry ; Lymphoid Tissue ; Lymphoma ; Lymphoma, Follicular* ; Sensitivity and Specificity ; Smad Proteins

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

TGF-β signaling plays a tumor suppressive role in normal and premalignant cells but promotes tumor progression during the late stages of tumor development. The TGF-β signaling pathway is tightly regulated at various levels, including transcriptional and post-translational mechanisms. Ubiquitination of signaling components, such as receptors and Smad proteins is one of the key regulatory mechanisms of TGF-β signaling. Tripartite motif (TRIM) family of proteins is a highly conserved group of E3 ubiquitin ligase proteins that have been implicated in a variety of cellular functions, including cell growth, differentiation, immune response, and carcinogenesis. Recent emerging studies have shown that some TRIM family proteins function as important regulators in tumor initiation and progression. This review summarizes current knowledge of TRIM family proteins regulating the TGF-β signaling pathway with relevance to cancer.
Carcinogenesis ; Humans ; Smad Proteins ; Transforming Growth Factor beta ; Ubiquitin ; Ubiquitin-Protein Ligases ; Ubiquitination

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

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

BACKGROUND: The transforming growth factor-β/SMAD (TGF-β/SMAD) pathway plays an important role in tissue repair and collagen synthesis. Low-level light therapy (LLLT) is increasingly used to alleviate pain and inflammation and promote wound healing. However, few studies have directly compared the effects of different wavelengths of light-emitting diodes (LEDs) or examined their individual effects at the molecular level. OBJECTIVE: Here we used a mouse model to investigate the effect of blue (410 nm), red (630 nm), and infrared (830 nm) LEDs on wound closure and assessed the underlying changes in a signal transduction pathway. METHODS: A full-thickness wound was created on the dorsal skin of mice using a 6-mm-diameter punch. In part I, the wounds were irradiated using blue, red, and infrared LEDs. In part II, the wounds were irradiated at different time points. Photo documentation, serial skin biopsies, wound measurements, and immunohistochemical staining using TGF-β/SMAD pathway-related molecules were performed. RESULTS: The overall wound closure percentage was highest during the first 10 days when an 830-nm LED was used. The wound closure process was accelerated when the irradiation was initiated immediately after wounding. Irradiation using 830-nm LED upregulated TGF-β and collagen-1 but downregulated SMAD7. CONCLUSION: Our findings show that LLLT using an 830-nm wavelength LED delivered immediately after wound formation may have the best effect on wound healing by upregulating the TGF-β/SMAD signaling pathway.
Animals ; Biopsy ; Collagen ; Inflammation ; Low-Level Light Therapy* ; Mice ; Signal Transduction ; Skin ; Smad Proteins ; Wound Healing* ; Wounds and Injuries*

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

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

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