Objective To investigate the effect of transforming growth factor-β1 (TGF-β1) gene transfer on the biological characteristics of osteoblasts. Methods The expression of TGF-β1 in the transfected osteoblasts was detected by in situ hybridization and assay of TGF-β1 activity in the supernatant (minklung epithelium cell growth -inhibition test). The effects of gene transfer andsupernatant of the transfected osteoblasts on the proliferation and alkaline phosphatase(ALP) activity of osteoblasts were detected by 3 H-TdR and MTT. Results The results of in situ hybridization analysis suggested that the osteoblasts transfected by TGF-β1 gene could express TGF-β1 obviously. The complex medium, which was the mixture of serum-free DMEM and the activated supernatant according to 1∶1, 1∶2, 1∶4, could inhibit growth of Mv-1-Lu evidently and the ratios ofinhibition were 16.3%, 22.7%, 28.2% respectively. TGF-β1 gene transfer hadno effect on the biological characteristics of osteoblasts, but the activated supernatant of transfected osteoblasts stimulated proliferation and inhibited ALPactivity of osteoblasts. Conclusion TGF-β1 gene transfer promotes the expression of TGF-β1 and the biological characteristics of trasfected osteoblasts are stable, which is helpful for gene therapy of bone defects in vivo.
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 explore the effectiveness of the transforming growth factor-β1(TGF-β1) and tumor necrosis factor-α(TNF-α) inducing human bronchial epithelial(HBE) cells to optimize epithelia-mesenchymal transformation(EMT) model. Methods Blank control, TGF-β1 10 ng/ml, TNF-α 10 ng/ml, TGF-β1 10 ng/ml+TNF-α 10 ng/ml induced human epithelial cells for 24 hours. Then the change of morphological alteration were observed by applying CCK8, cells migration assay and Western blot technique. Results When TGF-β1 plus TNF-α induced human epithelial cells for 24 hours, most of HBE cells traits changed including morphological alteration from cobblestone to fusiform, connection between cells vanishing, intercellular space broadening. In the experiments of checking cell migration capacity by the vitro scratch test, the group spacing was 420.06±10.38 μm in the blank control group, 499.86±34.00 μm in the TGF-β1 10 ng/ml group, 514.93±10.56 μm in the TNF-α 10 ng/ml group, 569.68±33.58 μm in the TGF-β1 10 ng/ml+TNF-α10 ng/ml group. TGF-β1 cooperated with TNF-α led to scratch spacing narrowing significantly. Western blot analysis showed that expression of E-cadherin and Vimentin varied significantly in the TGF-β1+TNF-α group. Conclusion Inducing human bronchial epithelial cell by TGF-β1 cooperated with TNF-α optimizes EMT model.
Objective To investigate the expression of vascular endothelial growth factor-A （VEGF-A） and the phenotypic transition after the activation of fibroblasts by the supernatant of cultured tumor cells．Methods The growth tendency of fibroblasts was tested by the MTT assay．The expressions of alpha-smooth muscle actin （α-SMA） and VEGF-A mRNA were tested by RT-PCR．The expressions of α-SMA and VEGF-A protein were tested by immunohistochemistry and Western blot．Results The MTT assay indicated that the conditional medium which contained tumor cells supernatant could obviously promote the growth of the fibroblasts． RT-PCR and Western blot manifested that α-SMA expressed by the fibroblasts which cultured by normal medium reached its peak on day 5，then decreased to a low level on day 7．When the medium contained 2 ng/ml transforming growth factor-β1 （TGF-β1），the fibroblasts could steadily express more α-SMA．But the above two mediums could not make the fibroblasts express the VEGF-A. When using the conditional medium，the α-SMA peak advanced on the third day and maintained at a high level，so as the expression of the VEGF-A．Conclusions The results suggested that fibroblasts can be activated to be myofibroblasts when using the conditional medium．The best activation time of the fibroblasts is consistent with the time of the VEGF-A expression at the highest level by the activated fibroblasts．The fibroblasts which activated at the best time are expected to become a kind of cells which can be used for promoting revascularization．
【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 study the influence of transforming growth factor-β1(TGF-β1), dentin non-collagen proteins(dNCPs) and their complexon tissue engineering pulp system. Methods Collagen I and dentin powder were used to construct the system of pulp cells in 3dimensional culture, dentin powder was added in the gel. The tissue engineering pulp were divided TGF-β1 group, dNCPs group, TGF-β1/dNCPsgroup and control group.After3, 6 and 14 days, the appearance and the differentiation of pulp cells were observed by HE staining and immunohistochemical staining -respectively. Results Collagen I could form netted collagen gel construction. Growing condition of pulp cells in gel was similar to that of pulp cells in vivo. After the TGF-β1 and dNCPswere added, the pulp cells had some characteristics of odontoblasts and had unilateral cell process after culture 6 days. Pulp cells arranged with parallel columnar and form dentin-pulp-like complex after 14 days. Immunohistochemical staining showed dentin salivary protein(DSP) began to express in some cells.The number of positive cell was most in the TGF-β1 group. No positive cells were detected in the control group. Conclusion The transforming growth factor-β1 and noncollagen proteins can stimulate the pulp cells to transform into odontoblasts to some extent, which promote the formation of tissue engineering pulp.
Objective To validate the mechanism of effect of hepatic artery ischemia on biliary fibrosis after liver transplantation and the prevention method. Methods Eighteen male dogs were established into the concise auto orthotopic liver transplantation models and assigned into three groups randomly: hepatic artery ischemia (HAI) group, TBB group (transferred the blood by a bridge duct ) and control group, each group contained 6 dogs. After opening portal vein, the samples were cut from liver in each group at the time of 6 h, 3 d and 14 d. The pathological modifications of intrahepatic bile ducts were observed and expression of transforming growth factor-β1 (TGF-β1) were detected in the three times. Expressions of Smad3 and phosphate-Smad3 as well as mRNA of α-smooth muscle actin (α-SMA) in intrahepatic bile ducts were detected 14 d after opening portal vein.Results Compared with control group, the collagen deposition and lumens stenosis in biliary vessel wall were more obviously in HAI group. In TBB group, the pathological modifications were slighter compared with HAI group. The positive cell index of TGF-β1 reached peak on day 3 after opening portal vein, then decreased in TBB group, and which in HAI group kept increase and was significantly higher than that in TBB group （Plt;0.05）. The expression level of phosphate-Smad3 and transcriptional level of α-SMA mRNA were 1.04±0.13 and 1.12±0.55 in TBB group on day 14 after opening portal vein, which were significantly higher than those in control group (0.59±0.09 and 0.46±0.18) and lower than those in HAI group (1.82±0.18 and 1.86±0.73), the diversities among three groups were significant (Plt;0.05). There was not significant difference of expression of Smads among three groups (Pgt;0.05). Conclusions Hepatic artery ischemia could increase the deposition of collagen fibers and the transdifferentiation of myofibroblast in bile duct and result in the biliary fibrosis by activating the TGF-β1/Smads signaling pathway. The bridging bypass device could lessen the biliary fibrosis caused by hepatic artery ischemia by inhibiting the activation of TGF-β1/Smads signal transduction passageway.
ObjectiveTo investigate the effect of diammonium glycyrrhizinate (DG) plus bone marrow mesenchymal stem cells (MSCs) transplantation in the treatment of acute exacerbation of pulmonary fibrosis induced by bleomycin (BLM) in rats.MethodsMSCs were isolated from male Wistar rats and cultured in vitro. Twenty-four female Wistar rats were randomly divided into 4 groups. The NC group was intratracheally injected with normal saline; the BLM group, the MSC group and the DGMSC group were intratracheally injected with BLM for 7 days; then the MSC group was injected with 0.5 mL of MSCs solution (2.5×106 cells) into the tail vein; the DGMSC group was intraperitoneally injected with DG for 21 days in a dose of 150 mg·kg–1·d–1 on the base of the MSCs injection. The rats were sacrificed on the 28th day and the lung tissue was extracted. Pathological examination was performed to determine the degree of alveolitis and pulmonary fibrosis. Immunofluorescence was used to detect the number and distribution of alveolar type Ⅱ epithelial cells. Alkali hydrolysis method was used to determine the content of hydroxyproline (HYP) in lung tissue; thiobarbituric acid method was used to measure the content of malondialdehyde (MDA) in lung tissue; colorimetric method was used to determine the superoxide dismutase activity (SOD) and total antioxidant capacity (T-AOC); enzyme linked immunosorbent assay was used to detect the expression levels of tumor necrosis factor-α (TNF-α ) and transforming growth factor-β1 (TGF-β1) in lung tissue homogenates.ResultsThe DG combined with MSCs injection can reduce the degree of alveolitis and pulmonary fibrosis in BLM model rats. The content of HYP and TGF-β1 in lung tissue homogenate of the DGMSC group were significantly lower than those in the MSC group (P<0.05). Meanwhile, DG combined with MSCs injection significantly increased the antioxidant capacity of the BLM model rats. MDA content decreased, SOD activity and T-AOC ability improved significantly in the DGMSC group compared with the MSC group (P<0.05). The alveolar type Ⅱ epithelial cells were significantly increased and the cell morphology was maintained in the DGMSC group compared with the MSC group.ConclusionsDG has a synergistic effect with MSCs in treatment of acute exacerbation of pulmonary fibrosis. The mechanism may be related to reducing inflammatory factors during pulmonary fibrosis, attenuating oxidative stress and promoting MSCs migration into lung tissue and transformation to alveolar type Ⅱ epithelial cells.
Objective To observe the effects of cigarette smoke extract ( CSE) on the proliferation and secretion of hydrogen peroxide ( H2O2 ) in human lung fibroblasts ( HLFs) induced by transforming growth factor-β1 ( TGF-β1 ) . Methods Cultured HLFs were divided into a normal group and a model group induced by TGF-β1 ( 5 ng/mL) , then intervened with CSE at different concentrations ( 0% , 2. 5% , 5% ,10% , respectively) . Brdu ELISA assay was used to detect cell proliferation. H2O2 release from cultured cells was assayed using a fluorimetric method. Cellular localization of H2O2 and expression of α-SMA were performed using a fluorescent-labeling strategy. Results TGF-β1 stimulated group showed positive expression of α-SMA, implying TGF-β1 had induced fibroblasts to differentiate into myofibroblasts. In TGF-β1 stimulated group, 2. 5% and 5% CSE promoted cell proliferation ( P lt; 0. 01 or 0. 05) , while 10% CSE inhibited cell proliferation ( P lt; 0. 01) . In the normal group, both low and high concentration of CSE inhibited cell proliferation ( P lt; 0. 01 or P lt; 0. 05) , and the inhibition effect was dose-dependent. HLF induced by TGF-β1 generated low constitutive levels of extracellular H2O2 that was markedly enhanced by CSE treatment ( P lt; 0. 01) . Pretreatment with DPI, an inhibitor of NADPH oxidase, abolished secretion of H2O2 . Cellular localization of H2O2 by a fluorescent-labeling strategy demonstrated that extracellular secretion of H2O2 is specific to the myofibroblast. Conclusions Low concentration of CSE can promote myofibroblast proliferation, and markedly increase extracellular secretion of H2O2 . CSE possibly take part in the development and progress of idiopathic pulmonary fibrosis by increasing oxidative stress.
Objective To study the inhibitory effects of curcumin on bleomycin-induced pulmonary fibrosis in rats at the fibrosing stage and explore its possible mechanism.Methods 96 male SD rats were randomly divided into a normal control group，a fibrosis model group，a fibrosis model treated with prednisone group and a fibrosis model treated with curcumin group.Pulmonary fibrosis were induced by instilled bleomycin through tracheal.From day 15 after bleomycin administration，the curcumin group and prednisone group were given curcumin（300 mg/kg） or prednisone（5 mg/kg） per day by intragastric administration，respectively.The normal control group and fibrosis model group were given 1% sodium carboxymethyl cellulose（10 mL/kg） as control.Six rats of each group were randomly sacrificed on day 21，28，42 and 56 after bleomycin administration，respectively.The histological changes of the lung were evaluated by HE and Masson’s trichrome staining.Lung expressions of transforming growth factor-β1（TGF-β1） and hydroxyproline were assessed by immuno-histochemistry and digestion method，respectively.Results Pulmonary fibrosis and hydroxyproline level in the curcumin group were significantly reduced as compared with those in the model group on day 42 and 56.The expession of TGF-β1 in the curcumin group was significantly lower than that in the model group on day 28，42 and 56，and was not significantly different from the normal group on day 56.Conclusion Curcumin could alleviate bleomycin-induced pulmonary fibrosis in rats at the fibrosing stage by inhibiting the expressions of TGF-β1.