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.
【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.
ObjectiveTo investigate the effect of dust fine particles on tumor necrosis factor-α (TNF-α), matrix metalloproteinase (MMP), transforming growth factor-β1 (TGF-β1), and collagens in the lung tissue of rats.MethodsAccording to random number table method, 96 male Wistar rats were divided into an untreated control group, a treated control group and an experimental group, with 32 rats in each group. The experimental group was exposed to the wind tunnel simulation of sandstorm (5 days per week, 5 hours per day); the untreated control group was put in the standard living environment next to the wind tunnel; the treated control group was exposed to the same wind tunnel simulation of sandstorm for 5 hours every day, the speed of wind was the same as the experimental group, but without dust; On the 30th, 60th, 90th, and 120th day, the levels of TNF-α, MMP-2, MMP-9, TGF-β1, lung collagen type Ⅰ and Ⅲ in the lung tissue of rats were determined by enzyme linked immunosorbent assay.ResultsCompared with the untreated control group and the treated control group, the content of TNF-α was higher in the experimental group on 30th, 60th, 90th and 120th day (all P<0.05). The contents of MMP-9 and MMP-2 in the experimental group on 60th and 90th day were significantly higher than those in the untreated group and the treated control group, respectively (all P<0.05). On the 30th, 60th, 90th, and 120th day, the content of TGF-β1 in the experimental group was significantly higher compared with the two control groups (all P<0.05). The contents of lung collagen type Ⅰ and type Ⅲ were higher in the experimental group on 60th, 90th and 120th day, respectively, compared with the two control groups (all P<0.05).ConclusionsThe strong sandstorm environmental exposure to a certain period of time can promote lung interstitial collagen deposition in rat. With the prolonged exposure time, the deposition of collagen increases. TNF-α, MMP-2, MMP-9 and TGF-β1 may all participate and induce the process of pulmonary fibrosis.
ObjectiveTo investigate the effects of 3-(5'-hydroxymethyl-2'-furyl)-1-benzylindazole (YC-1), a hypoxia-inducible factor-1α (HIF-1α) inhibitor, on hypoxia induced rat pulmonary arterial adventitial fibroblasts (AFs) proliferation and collagen synthesis, and explore the molecular mechanism.MethodsUnder hypoxic condition, rat AFs were cultured in DMEM medium supplemented with 10% fetal bovine serum in vitro. The cells were divided into five groups, ie. a normoxia group, a hypoxia group and three hypoxia+YC-1 groups (treated with YC-1 at concentration of 0.01, 0.05 and 0.1 mmol/L, respectively). The cells proliferation was determined by MTT method. Collagen synthesis of AFs was measured by 3H-proline incorporation assay. The expression of HIF-1α in AFs in different conditions was measured by Western blot, and the mRNA expression of transforming growth factor-β1 (TGF-β1) was measured by reverse-transcription polymerase chain reaction.ResultsThe proliferation rate and the incorporation data of 3H-proline in the hypoxia group were significantly increased as compared with those in the control group (both P<0.01). YC-1 significantly reduced the proliferation rate and incorporation data of3H-proline induced by hypoxia in a dose-dependent manner. YC-1 could also down-regulate the expressions of HIF-1α and TGF-β1 mRNA significantly (both P<0.01). Compared with the hypoxia group, the expressions of HIF-1α and TGF-β1 mRNA decreased respectively by 65% and 61% in the hypoxia+YC-1 (0.1 mmol/L) group (bothP<0.01).ConclusionsYC-1 can inhibit hypoxia-induced AFs proliferation and collagen synthesis in a dose-dependent manner. The mechanism may relate to YC-1’s inhibitory effect on expressions of HIF-1α and TGF-β1 mRNA.
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.
For observation of the change of transforming growth factor-beta 1 (TGF-beta 1) gene expression in the process of skin wound healing, the following experiments were performed. Sixteen Wistar rats were chosen. At each side of the rat’s back, a 1 cm x 1.5 cm middle-thick skin wound was made. After 3, 6, 9 and 12 days, the specimens were taken from the wounds. For each specimen, half of it was used for RNA extraction, and underwent dot blotting; and the other half was frozen immediately and underwent in situ hybridization. The probes were dig-labeled PDGF-BB cDNA probe and TGF-beta 1 probe. The results showed that TGF-beta 1 gene was expressed mainly in fibroblast, epithelial cell and capillary endothelial cell. The peak of TGF-beta 1 mRNA content was in the 6th day postoperatively. After that, the content of TGF-beta 1 decreased to normal. It was suggested that TGF-beta 1 gene expression was in close relation with healing process. TGF-beta 1 may play an important regulatory role in the skin wound healing.
Objective To study the pathology and possible mechanism of experimental hydrochloric acid（HCl） inhalation-indued pulmonary fibrosis in rats.Methods 120 male SD rats were randomly divided into a nomal control group，a bleomycin group，a high dose HCl group，a middle dose HCl group and a low dose HCl group.The bleomycin group was intratracheally injected with bleomycin once to induce pulmonary fibrosis.The three HCl groups were intratracheally injected with HCl once per week.The control group was given saline by the same way.Six rats of each group were randomly sacrificed on day 7，14，28 and 42 respectively.The histological changes of lung tissue were studied by HE and Masson’s trichrome staining.Hydroxyproline level in lung tissue was measured by digestion method.Protein and mRNA expression of transforming growth factor-β1（TGF-β1） were assayed by immunohistochemistry and RT-PCR respectively.Results Alveolitis in three HCl groups was significantl compared to control group，most severe at the second week，then remained at a high level which was equivalent to or exceeded the level of the bleomysin group after 28 days.Pulmonary fibrosis in three HCl groups was also significantly more severe than that in the control group，but milder than that in the bleomysin group.The high-dose and middle-dose HCl groups were not significantly different from the bleomysin group on day 42.There was no difference between three HCl groups in the earlier period，but the high-dose HCl group has a significantly difference from low-dose group on day 42.The content of hydroxyproline in high-dose and middle-dose HCl groups was also significantly higher than that in the control group.On day 42 hydroxyproline content in high-dose HCl dose rather middle –or low dose group was similiar with the level of bleomysin group.Content of TGF-β1 mRNA in three HCl groups was comparable to the level of bleomysin group on day 28 and exceeded on day 42.The expression of TGF-β1 in three HCl groups was not significantly different from the bleomysin group on day 42.Conclusion Experimental acid aspiration might contribute to pulmonary fibrosis in rats.Acid induced alveolar epithelial cell damage，abnormal proliferation and repair and fibrosis could be involved..
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 observe the effects of different doses of atorvastatin on bleomycin-induced pulmonary fibrosis in rats. Methods Seventy-five healthy female SD rats were randomly divided into five groups ( 15 rats in each group) , ie. a normal group , a model group, a 10 mg/ kg atorvastatin-treated group, a 20 mg/ kg atorvastatin-treated group, and a 40 mg/ kg atorvastatin-treated group. The rats in the model group and treatment groups were instilled with bleomycin in trachea( 5 mg/kg) , and the normal group were instilled with equal volume of normal saline. The treatment groups were gastric gavaged with different doses of atorvastatin each day from2 nd day on after instillation, and the normal group and model group were gavaged with normal saline. Blood samples were obtained from abdominal aorta in five rats in each group and blood gas analysis was performed on1st week, 2nd week and 4th week respectively after BLM instillation. Then the animals were killed and lung tissue samples were harvested for histopathology study. HE and Masson staining were used to determine the extent of alveolus inflammation and pulmonary fibrosis respectively.Histoimmunochemical stain were used to determine the protein levels of transforming growth factor-β1 ( TGF-β1 ) and connective tissue growth factor( CTGF) in pulmonary tissues. Results The arterial partial pressure of oxygenate ( PaO2 ) in the treatment groups were increased gradually with the increasing of therapeutic dose at each time point and decreased with prolongation of time in the same group. The protein levels of TGF-β1 and CTGF in pulmonary tissues were decreased gradually with prolongation of time. TGF-β1 and CTGF expressed obviously less in the treatment groups than those in the model group at each time point .The higher therapeutic doses were, the less the expressions of TGF-β1 and CTGF were. Conclusion Atorvastatin has remarkable inhibitory effects on BLM-induced pulmonary fibrosis of rats in a dose- and timedependentmanner.