Oral mucositis, a severe oral ulceration, is a common toxic effect of radio- or chemoradio-therapy and a limiting factor to using the maximum dose of radiation for effective cancer treatment. Among cancer patients, at least 40% and up to 70%, of individuals treated with standard chemotherapy regimens or upper-body radiation, develop oral mucositis. To date, there is no FDA approved drug to treat oral mucositis in cancer patients. The key challenges for oral mucositis treatment are to repair and protect ulcerated oral mucosa without promoting cancer cell growth. Oral mucositis is the result of complex, multifaceted pathobiology, involving a series of signaling pathways and a chain of interactions between the epithelium and submucosa. Among those pathways and interactions, the activation of nuclear factor-kappa B (NF-κB) is critical to the inflammation process of oral mucositis. We recently found that activation of TGFβ (transforming growth factor β) signaling is associated with the development of oral mucositis. Smad7, the negative regulator of TGFβ signaling, inhibits both NF-κB and TGFβ activation and thus plays a pivotal role in the prevention and treatment of oral mucositis by attenuating growth inhibition, apoptosis, and inflammation while promoting epithelial migration. The major objective of this review is to evaluate the known functions of Smad7, with a particular focus on its molecular mechanisms and its function in blocking multiple pathological processes in oral mucositis.
Animals ; Humans ; Mouth Diseases ; metabolism ; pathology ; prevention & control ; Smad7 Protein ; metabolism ; Stomatitis ; metabolism ; pathology ; prevention & control

Transforming growth factor-β (TGF-β) is a driving force of renal fibrosis, which may lead to chronic kidney diseases and even end stage renal diseases. By activating canonical and non-canonical signaling pathways, TGF-β promotes the synthesis of extracellular matrix while preventing their degradation. In the injured kidney, TGF-β induces apoptosis, proliferation and fibrotic response of renal cells including epithelial cells, endothelial cells, podocytes, fibroblasts, pericytes and macrophages, and it also promotes transdifferentiation, activation and proliferation of myofibroblasts. Additionally, TGF-β exerts profibrotic effects by interplaying with other signaling pathways like BMP-7, Wnt/β-catenin and MAP kinase. Smad3 is the central pathological gene in renal fibrosis, and epigenetic regulation of TGF-β/Smad3 is a hot topic in kidney field. Although direct targeting TGF-β may cause side effects including tumorigenesis and immune diseases, the therapeutic strategies targeting the balance of downstream Smad3 and Smad7 may prevent or delay the progression of fibrotic kidney disease.
Epigenesis, Genetic ; Fibrosis ; Humans ; Kidney Diseases ; pathology ; Signal Transduction ; Smad3 Protein ; metabolism ; Smad7 Protein ; metabolism ; Transforming Growth Factor beta ; metabolism

No abstract available.
Crohn Disease/*drug therapy ; Female ; Humans ; Immunosuppressive Agents/*administration & dosage ; Male ; Oligonucleotides/*administration & dosage ; Smad7 Protein/*antagonists & inhibitors

OBJECTIVETo investigate the relationship between expression of Smad3, Smad7 and ventricular remodeling in rats after myocardial infarction.

METHODSMyocardial infarction was induced by left anterior descending coronary artery ligation in rats (n = 11) and sham-operated rats were used as control (n = 10). The rats were sacrificed 8 weeks later. Heart weight/body weight (HW/BW), mean blood pressure, left ventricular end diastolic pressure (LVEDP), collagen content in the un-infarcted area were examined. The mRNA levels of transforming growth factor (TGF)beta(1), Smad 3, Smad7 were determined by RT-PCR.

RESULTCompared with controls, the level of HW/BW, LVEDP and collagen content were significant increased. The mRNA expression of TGFbeta(1) and Smad3 was significantly increased in areas of myocardial infarction, border of the infarction, interventricular septum and right ventricle. The expression of Smad7 mRNA in these areas was decreased.

CONCLUSIONThese results indicated that TGFbeta(1)-Smads signaling was correlated to the ventricular remodeling after myocardial infarction. Smad3 might promote the process while Smad7 inhibit the process.

Animals ; Male ; Myocardial Infarction ; metabolism ; physiopathology ; RNA, Messenger ; metabolism ; Rats ; Rats, Wistar ; Smad3 Protein ; genetics ; metabolism ; Smad7 Protein ; genetics ; metabolism ; Transforming Growth Factor beta ; metabolism ; Ventricular Remodeling

OBJECTIVETo explore the effects of Sini Decoction (SD) on the expressions of Samd2 and Smad7 isoproterenol (Iso) induced myocardial fibrosis rats.

METHODSTotally 19 Wistar rats were randomly divided into 3 groups, i.e., the control group, the model group, and the SD group. Iso was injected to rats in the model group and the SD group, while normal saline was injected to rats in the control group. SD was given to rats in the SD group by gastrogavage, while normal saline was administered to rats in the control group and the model group by gastrogavage. Four weeks later Masson staining and electron microscopic analysis were performed in each group. The protein and mRNA expressions of Smad2 and Smad7 were detected using immunohistochemical assay and RT-PCR.

RESULTSMasson staining showed the IOD value of the myocardial collagen fiber was 9 303 in the model group, 2 459 in the SD group, and 4 224 in the control group, indicating the myocardial fibrosis was more obvious in the model group than in the SD group and the control group. The IOD value of Smad2 protein was 20 275 and the mRNA IOD of Smad2 protein was 0. 919 in the model group, while they were respectively 9 949 and 0. 561 in the SD group, indicating the protein and mRNA expressions of Smad2 were obviously higher in the model group than in the SD group (P < 0.05). The IOD value of Smad7 protein was 25 667 and the mRNA IOD of Smad7 protein was 0.222 in the model group, while they were respectively 93 147 and 0. 412 in the SD group, indicating the protein and mRNA expressions of Smad7 was obviously lower in the model group than in the SD group (P < 0.05).

CONCLUSIONSD could effectively inhibit Iso induced myocardial fibrosis, and its mechanism may be associated with down-regulating the expression of Smad2 and up-regulating the expression of Smad7.

Animals ; Cardiomyopathies ; metabolism ; pathology ; Drugs, Chinese Herbal ; pharmacology ; Fibrosis ; Isoproterenol ; adverse effects ; Male ; Myocardium ; metabolism ; pathology ; Rats ; Rats, Wistar ; Smad2 Protein ; metabolism ; Smad7 Protein ; metabolism

Objective To investigate the effect of SMAD family member 3(SMAD3) silenced by small interfering RNA (siRNA) on macrophage polarization and transforming growth factor β1 (TGF-β1)/ SMAD family signaling pathway in rheumatoid arthritis (RA). Methods RA macrophages co-cultured with rheumatoid arthritis fibroblast-like synoviocytes (RA-FLS) were used as a cell model. TGF-β1 was used to stimulate macrophages, and SMAD3-specific siRNA (si-SMAD3) and negative control siRNA (si-NC) were transfected into human RA macrophages co-cultured in Transwell^TM chamber. The expression of SMAD3 mRNA was detected by real-time fluorescence quantitative PCR, and the expression of TGF-β1, SMAD3 and SMAD7 protein was detected by Western blot analysis. The contents of TGF-β1 and IL-23 in cell culture supernatant were determined by ELISA. Cell proliferation was detected by CCK-8 assay. Transwell^TM chamber was used to measure cell migration. Results Compared with the model group and the si-NC group, the expression of TGF-β1, SMAD3 mRNA and protein in RA macrophages decreased significantly after silencing SMAD3. In addition, the secretion of IL-23 decreased significantly, and the cell proliferation activity and cell migration were inhibited, with high expression of SMAD7. Conclusion Knockdown of SMAD3 can promote M2 polarization and SMAD7 expression in RA macrophages.
Humans ; Arthritis, Rheumatoid/genetics* ; Interleukin-23 ; Macrophages ; RNA, Messenger ; RNA, Small Interfering/genetics* ; Smad7 Protein/genetics* ; Transforming Growth Factor beta1/genetics* ; Smad3 Protein/genetics* ; Gene Silencing

OBJECTIVETo examine the expression of TGF-beta1, Smad7 and cell apoptosis in oral lichen planus (OLP) and to evaluate the possible pathogenesis of oral lichen planus.

METHODSImmunohistochemical technique was used to study the expression of TGF-beta1 and Smad7 in the epithelia cells of 17 OLP cases and 7 normal oral mucosa (NOM). TUNEL was used for detecting the cell apoptosis in 17 OLP cases and 7 NOM.

RESULTSTGF-beta1 was moderately positive in the epithelia cells of OLP. All the epithelia cells in OLP showed strong cytoplasmic staining. The expression of TGF-beta1 and Smad7 were significantly increased in OLP compared with that in NOM (P < 0.05). Cell apoptotic index (AI) was remarkably increased in epithelia cells in OLP cases, and the cell apoptosis was localized in basal and suprabasal epithelial layers. There was a positive correlation between TGF-beta1 expression and cell apoptosis in the epithelia of OLP (r = 0.69, P <0.05).

CONCLUSIONSHigh expression of TGF-beta1 and Smad7 in the epithelia of OLP suggests that TGF-beta1-Smad7 signal pathway was disturbed in oral lichen planus. The imbalance of TGF-beta1-Smad7 pathway may contribute to the mechanisms of cell apoptosis of epithelial cells in OLP.

Apoptosis ; Case-Control Studies ; Epithelium ; metabolism ; pathology ; Female ; Humans ; Lichen Planus, Oral ; metabolism ; Male ; Mouth Mucosa ; metabolism ; pathology ; Smad7 Protein ; metabolism ; Transforming Growth Factor beta1 ; metabolism

OBJECTIVETo establish a rabbit model of silicotic pulmonary fibrosis and to investigate the effect of cordyceps sinensis in this model.

METHODSThirty healthy male white rabbits were randomly divided into control group, silicosis model group, and intervention group. The rabbits in silicosis model group and intervention group received endotracheal perfusion of silicon dioxide suspension (120 mg/kg), and the control group was treated with the same volume of saline. All the rabbits were sacrificed 30 days later. The lung coefficient was calculated by comparing the lung weight and body weight; the right lung tissue was stained with hematoxylin-eosin (HE). The content of hydroxyproline in lung tissue was measured by alkaline hydrolysis. The mRNA levels of transforming growth factor beta 1 (TGF-β₁) and mothers against decapentaplegic homolog 7 (Smad7) in rabbit lung sections were determined by real-time PCR.

RESULTSNo abnormalities were observed by HE staining in the lung tissues of control group, while fibrosis and silicotic nodules were discovered in the silicosis model group and intervention group. The lung coefficient and the content of hydroxyproline in lung tissue were significantly higher in the silicosis model group than in the control group and intervention group (P < 0.05 or P < 0.01). Compared with the control group, the silicosis model group and intervention group had significantly increased TGF-β₁ mRNA levels but significantly reduced Smad7 mRNA levels (P < 0.02). Compared with the silicosis model group, the intervention group had a significantly reduced TGF-β₁ mRNA level but a significantly increased Smad7 mRNA level (P < 0.05).

CONCLUSIONCordyceps sinensis is able to reduce the expression of TGF-β₁ mRNA and increase the expression of Smad7 mRNA in lung tissues of rabbits with silicotic pulmonary fibrosis, and thus postpone the progression of fibrosis.

Animals ; Cordyceps ; chemistry ; Disease Models, Animal ; Lung ; metabolism ; Male ; Pulmonary Fibrosis ; drug therapy ; metabolism ; Rabbits ; Silicosis ; drug therapy ; metabolism ; Smad7 Protein ; metabolism ; Transforming Growth Factor beta1 ; metabolism

OBJECTIVETo construct a tetracycline-inducible eukaryotic expression vector of rat Smad7.

METHODSThe total RNA was extracted from normal rat kidney with Trizol agent. Rat Smad7 cDNA fragment was cloned by RT-PCR, and was inserted into the restriction site between Nhe I and Hind III of the inducible eukaryotic expression vector pBI-L by tetracycline. pBI-L-Smad7 was constructed by digestion and ligation, and detected by restriction endonuclease digestion and sequencing.

RESULTSThe recombinant eukaryotic expression vector pBI-L-Smad7 was constructed correctly as confirmed by restriction endonuclease digestion and sequencing. The fragment of pBI-L-Smad7 digested with restriction endonucleases and the sequence of inserted Smad7 cDNA were consistent with the results of theoretical analysis.

CONCLUSIONThe tetracycline- inducible eukaryotic expression vector of rat Smad7, pBI-L-Smad7, is constructed successfully, which may facilitate further clinical study of Smad7 gene therapy for tissue and organ fibrosis.

Animals ; Cloning, Molecular ; DNA, Complementary ; genetics ; Eukaryotic Cells ; metabolism ; Gene Expression ; drug effects ; Genetic Therapy ; Genetic Vectors ; genetics ; Rats ; Rats, Sprague-Dawley ; Smad7 Protein ; biosynthesis ; genetics ; Tetracycline ; pharmacology

OBJECTIVETo investigate the effect of Smad7 on the expressions of collagen I and alpha-smooth muscle actin (alpha-SMA) in HSC-T6 cell line activated by transforming growth factor-beta1 (TGF-beta1).

METHODSHSC-T6 cells stably expressing M2-flag protein were selected after co-infection of the cells with pTRE-Smad7-M2-flag and pTet-on. The optimal dose of doxycycline for inducing Smad7 was determined, and the effects of Smad7 over-expression on the expressions of collagen I and alpha-SMA in the cells activated by TGF-beta1 and on Smad2/3 phosphorylation were evaluated using Western blotting.

RESULTSThe optimal dose of doxycycline for inducing Smad7 expression was 2 mg/L. Smad7 over-expression induced by doxycycline decreased the expressions of collagen I and alpha-SMA in HSC-T6 cells activated by TGF-beta1, and down-regulated the level of Smad2/3 phosphorylation.

CONCLUSIONSmad7 over-expression inhibits Smad2/3 phosphorylation, and decreases the expression of collagen I and alpha-SMA in HSC-T6 cells induced by TGF-beta1 to inhibit the progression of liver fibrosis.

Actins ; genetics ; metabolism ; Cells, Cultured ; Collagen Type I ; genetics ; metabolism ; Genetic Therapy ; Hepatocytes ; cytology ; metabolism ; Humans ; Liver Cirrhosis ; metabolism ; therapy ; Smad7 Protein ; pharmacology ; Transforming Growth Factor beta1 ; pharmacology