Objective To observe the expression and distribution of transforming growth factor-β1 (TGF-β1) in the healing process of bile duct and discuss its function and significance in the process of benign biliary stricture formation. Methods An injury to bile duct of dog was made and then repaired. The expression and distribution of TGF-β1 in the tissue at different time of the healing process were studied after operation with immunohistochemical SP staining. Results TGF-β1 staining was observed in the granulation tissue, fibroblasts and endothelial cells of blood vessels. High expression of TGF-β1 was observed in the healing process lasting for a long time. Conclusion The high expression of TGF-β1 is related closely with the fibroblast proliferating activity, extracellular matrix overdeposition and scar proliferation in the healing process of bile duct.
Objective To review the recent advances in transforming growth factor-β(TGF-β) super family study and its role in new bone formation. Methods The latest original articles related to this subject were retrieved extensively,especially the effect of TGF-β, bone morphogenetic proteins(BMPs) and activin(ACT) on distractionosteogenesis. Results TGF-β, BMPs and ACT play important roles in prompting new bone formation and each of them has different effects. Among them, TGF-β can stimulate the proliferation of osteoblast and synthesis ofextra cellular medium; BMPs can initiate the differentiation of interstitial cell toosteocyte; then ACT displays the combine effect of above two factors. Conclusion TGF-β superfamily can regulate new bone formation and thus shorten the course of mandibular distraction osteogenesis.
Objective To investigate the effects of adenovirus-mediated melanoma differentiation-associated gene-7 (mda-7)/IL-24 and/or adriamycin (ADM) on transplanted human hepatoma in nude mice and to explore a new way for hepatoma gene therapy combined with chemotherapy. Methods The recombinant adenovirus vector carrying Ad.mda-7 was constructed; Ad.mda-7 and/or ADM were injected into the tumor-bearing mice. Their effects on the growth of the tumor and the survival time of the mice were observed. The expressions of VEGF and TGF-β1 were detected by an immunohistochemistry method. Results Ad.mda-7 was constructed and expressed in vivo successfully. Compared with other three groups 〔control group (43.4±1.67) d, ADM group (64.2±4.14) d, Ad.mda-7 group (61.4±1.67) d〕, the mice treated with Ad.mda-7 combined with ADM had longer average survival time 〔(83.8±4.82) d, P＜0.01〕; the average size of tumor treated with Ad.mda-7 combined with ADM diminished significantly compared with that treated with ADM or Ad.mda-7 separately (P＜0.01). VEGF and TGF-β1 expressions of Ad.mda-7 group were (56.2±7.7)%, (35.2±4.5)%, respectively, and were lower than those in ADM group (VEGF: P＜0.05; TGF-β1: P＜0.01). VEGF expression of Ad.mda-7+ADM group was (37.3±5.0)%, and was significantly lower than that in other three groups (P＜0.01). TGF-β1 expression of Ad.mda-7+ADM group was (31.2±3.1)% and significantly lower than that in control group and ADM group (P＜0.01), however, there was no significant difference compared with Ad.mda-7 group (Pgt;0.05). Conclusion Ad.mda-7 combined with ADM has b antitumor potency and synergistic effects and suppresses the growth of human HCC xenograft in nude mice, possibly by inducing the apoptosis of hepatoma cell lines and suppressing tumor angiogenesis.
Objective To observe the differences in protein contents of three transforming growth factorbeta(TGF-β) isoforms, β1, β2, β3 andtheir receptor(I) in hypertrophic scar and normal skin and to explore their influence on scar formation. Methods Eight cases of hypertrophic scar and their corresponding normal skin were detected to compare the expression and distribution of TGF-β1, β2, β3 and receptor(I) with immunohistochemistry and common pathological methods. Results Positive signals of TGF-β1, β2, and β3 could all be deteted in normal skin, mainly in the cytoplasm and extracellular matrix of epidermal cells; in addition, those factors could also be found in interfollicular keratinocytes and sweat gland cells; and the positive particles of TGF-β R(I) were mostly located in the membrane of keratinocytes and some fibroblasts. In hypertrophic scar, TGF-β1 and β3 could be detected in epidermal basal cells; TGFβ2 chiefly distributed in epidermal cells and some fibroblast cells; the protein contents of TGF-β1 and β3 were significantly lower than that of normal skin, while the change of TGF-β2 content was undistinguished when compared withnormalskin. In two kinds of tissues, the distribution and the content of TGF-β R(I) hadno obviously difference. ConclusionThe different expression and distribution of TGF-β1, β2 andβ3 between hypertrophic scar and normal skin may beassociated with the mechanism controlling scar formation, in which the role of the TGF-βR (I) and downstream signal factors need to be further studied.
【Abstract】Objective To investigate the apoptosis induced by TGF-β1 in human hepatic carcinoma cell lines and its relationship with p53 gene and Smad. Methods Three human hepatic carcinoma cell lines which involving in various status of the p53 gene were used in this study. TGF-β1-induced apoptosis in hepatic carcinoma cell lines was measured by the terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) assay. To study the mechanism of TGF-β1-induced apoptosis, these cell lines were transfected with a TGF-β1-inducible luciferase reporter plasmid containing Smad 4 binding elements (SBE) and luciferase gene using Lipofectamine 2000, then treated with TGF-β1, relative luciferase activity was assayed. Results Of three cell lines studied with TUNEL assay, TGF-β1 induced apoptosis was observed in HepG2 cells (wild type p53). Huh-7 (mutant p53) and Hep3B (deleted p53) cell lines showed less apoptosis. Luciferase activity assay indicated that the response to TGF-β1 induction in HepG2 cells was increased dramatically but was not significant in Huh-7 and Hep3B cell lines. Conclusion HepG2 cells seem to be highly susceptible to TGF-β1-induced apoptosis compared with Hep3B and Huh7 cell lines. Smad 4 is a central mediator of the TGF-β1 signal transduction pathway.
Objective To investigate the effects of bursopentin ( BP5) on expression of extracellular matrix in human lung fibroblasts ( HLFs) and its mechanism.Methods HLFs were cultured in vitro and divided into five groups. The cells in the control group were cultured in DMEMwithout TGF-β1 or BP5. The cells in TGB-β1 treatment group were cultured in DMEMcontaining 5 μg/L TGF-β1 . While in three TGF-β1 + BP5 treatment groups, the cells were cultured in DMEM containing 5 μg/L TGF-β1 and simultaneously intervened with BP5 at three different concentrations ( 2. 5 μg/mL, 5 μg/mL, and 10 μg/mL respectively) . The expression of α-SMA was detected using a fluorescent-labeling strategy. The expressions of Collagen-Ⅰ, p-Smad2/3, p-Smad3, and Smad7 proteins were measured by Western blot. Results The cells in the TGF-β1 treatment group showed positive expression of α-SMA, implying TGF-β1 had induced fibroblasts to differentiate into myofibroblasts. In the TGF-β1 treatment group, the expressions of collagen-Ⅰ( 1. 402 ±0. 158 vs. 0. 605 ±0. 367) , p-Smad2/3 ( 1. 457 ±0. 111 vs. 0. 815 ±0. 039) , and p-Smad3 ( 1. 320 ±0. 147 vs. 0. 623 ±0. 128) increased with statistical significance ( P lt; 0. 01) . Meanwhile the expression of Smad7 reduced ( 0. 614 ±0. 107 vs. 0. 865 ±0. 063, P lt;0. 05) . But in the TGF-β1 + BP5 treatment groups, over-expressions of collagen-Ⅰ, α-SMA, p-Smad2 and p-Smad3 induced by TGF-β1 were obviously inhibited by BP5, especially at the BP5 concentration of 10 μg/mL ( collagen-Ⅰ: 0. 718 ±0. 049 vs. 1. 402 ±0. 158; p-Smad2 /3: 0. 696 ±0. 031 vs. 1. 457 ±0. 111; p-Smad3: 0. 766 ±0. 006 vs. 1. 320 ±0. 147; all P lt; 0. 01) . Otherwise, the up-regulation of Smad7 ( 1. 237 ±0. 173 vs. 0. 614 ±0. 107) was found.Conclusions Bursopentin can reduce the expressions of collagen-Ⅰ and α-SMA protein of fibroblast stimulated by TGF-β1 , maybe through inhibiting TGF-β1 /Smads transduction pathway. It is suggested that bursopentin may have intervention effect on pulmonary fibrosis.
Objective To investigate the effect of imatinib mesylate on radiation-induced lung injury mice and its influence on the oxidative stress and transforming growth factor-β1 (TGF-β1) expression in mice. Methods Forty-five C57BL/6 mice were divided into a treatment group, a control group and a model group. The treatment group and model group were given radiation of 18 Gy delivered in the thorax. After 4 h daily of the radiation, the treatment group received imatinib mesylate of 0.081 g/kg, while the other groups were given normal saline solution. The experiments were continued for 30 days. After the experiments, the lungs of mice were divided into 4 parts. The haematoxylin and eosin and immunohistochemical stain were prepared to observe the situation of pathology and TGF-β1. The lung homogenate was prepared and the levels of superoxide dismutase (SOD), malondialdehyde (MDA), total antioxidant capacity (T-Aoc) and glutathione peroxidase (GSH-PX) were detected. Results The levels of GSH-PX, T-Aoc and SOD were (173.15±12.21) U, (119.33±11.06) U/mgprot and (1.73±0.33) nmol/mgprot in the treatment group, significantly higher than the control group, while the levels of MDA was (0.68±0.08) nmol/mgprot, significantly lower than the control group (P<0.05). The HE and immunohistochemical stain showed that there were mild alveolar inflammatory changes in the treatment group while such changes were serious in the model group. The scores of HE and immunohistochemical were 1.26±0.12 and 0.31±0.12 in the treatment group, significantly lower than those in the control group (P<0.05). Conclusion The imatinib mesylate can effectively ameliorate the oxidative stress and inhibite TGF-β1 expression in radiation-induced lung injury mice.
OBJECTIVE: To localize the distribution of basic fibroblast growth factor (bFGF) and transforming growth factor-beta(TGF-beta) in tissues from dermal chronic ulcer and hypertrophic scar and to explore their effects on tissue repair. METHODS: Twenty-one cases were detected to localize the distribution of bFGF and TGF-beta, among them, there were 8 cases with dermal chronic ulcers, 8 cases with hypertrophic scars, and 5 cases of normal skin. RESULTS: Positive signal of bFGF and TGF-beta could be found in normal skin, mainly in the keratinocytes. In dermal chronic ulcers, positive signal of bFGF and TGF-beta could be found in granulation tissues. bFGF was localized mainly in fibroblasts cells and endothelial cells and TGF-beta mainly in inflammatory cells. In hypertrophic scar, the localization and signal density of bFGF was similar with those in granulation tissues, but the staining of TGF-beta was negative. CONCLUSION: The different distribution of bFGF and TGF-beta in dermal chronic ulcer and hypertrophic scar may be the reason of different results of tissue repair. The pathogenesis of wound healing delay in a condition of high concentration of growth factors may come from the binding disorder of growth factors and their receptors. bFGF may be involved in all process of formation of hypertrophic scar, but TGF-beta may only play roles in the early stage.
Objective To investigate the effects of sodium ferulate on lung mRNA expression of TGF-β1 signal transduction molecule in rats with pulmonary fibrosis，and explore the mechanism of sodium ferulate on pulmonary fibrosis.Methods A rat model of pulmonary fibrosis was induced by intratracheal injection of bleomycin (5 mg/kg).Thirty SD rats were randomly divided into three groups (n=10 in each group)，ie.a control group，a pulmonary fibrosis model group，and a sodium ferulate group.The lung histopathology and the expression of collagen was examined by HE staining and collagen fibril staining respectively.The expressions of TGF-βRII and Smad4 mRNA in the lung tissue were detected by situ hybridization.And the expression of TGF-β1 mRNA was detected by real-time fluorescence-quantification RT-PCR.Results Collagen fibril staining indicated that the expression of pulmonary collagen in the model group was significantly higher than that in the control group and sodium ferulate group (Plt;0.001).The mRNA expressions of pulmonary TGF-β1，TGF-βRII and Smad4 were significantly higher in the model group than those in the control group (all Plt;0.01)，and were significantly lower in the sodium ferulate group than those in the model group (all Plt;0.05).Conclusions Sodium ferulate can effectively reduce pulmonary fibrosis through inhibition of the mRNA expression of TGF-β1，TGF-βRII and Smad4 in the lung tissue，thus influence the TGF-β1/Smad4 signal transduction way and inhibit the target gene activation.
OBJECTIVE: To explore the expression of alpha-smooth muscle actin (alpha-SMA) induced by transforming growth factor beta 1 (TGF-beta 1). METHODS: Five samples of hypertrophic scars and three samples of normal mature scars were collected as the experimental and control groups respectively. The fibroblasts were isolated from scars, and cultured in 2-dimension or 3-dimension culture system. The immunohistochemical staining method of LSAB were used to investigate the expression of alpha-SMA in fibroblasts in the different concentration of TGF-beta 1. RESULTS: The expression of alpha-SMA in 3-dimension culture system were markedly lower than those in 2-dimension culture system with respect to the fibroblasts in the experimental group. The expression of alpha-SMA in fibroblasts were different in response to various TGF-beta 1 concentration, it was more effective at the concentration of 5 ng/ml. The expression of alpha-SMA in the fibroblasts from hypertrophic scars seemed to be more sensitive to TGF-beta 1 compared to that of the normal mature scars. CONCLUSION: There are concentration-dependent in the expression of alpha-SMA induced by TGF-beta 1 in scar fibroblasts in vitro. The biological characteristics of the fibroblasts from hypertrophic scars and normal mature scars and their sensitivity to the inducement of TGF-beta 1 were different. The inducement of TGF-beta 1 may be depressed by extracellular matrix components and that may decrease the expression of alpha-SMA.