目的:研究转化生长因子β1(TGF-β1)促进Tenon囊成纤维细胞的增殖作用及核心蛋白多糖(decorin)对TGF-β1促Tenon囊成纤维细胞增殖的影响。方法:(1)取青光眼患者的Tenon囊组织,采用组织块贴壁培养法进行原代培养细胞培养,细胞经过冷冻与复苏后,观察细胞形态结构与生物学特性。(2)用不同浓度(0.01、0.1、1、5、10ng/mL)TGF-β1作用于Tenon囊成纤维细胞48 h。(3)终浓度为5 ng/mL的TGF-β1 和不同浓度(0.01、0.1、1、2、5μg/mL)的decorin共同作用于Tenon囊成纤维细胞48h。MTT比色法检测Tenon囊成纤维细胞增殖。结果:(1)体外成功培养Tenon囊成纤维细胞,细胞生长活跃,形状稳定,细胞经过冷冻与复苏后,仍能保持其原来的细胞形态结构与稳定的生物学特性。(2)1~10ng/mL TGF-β1能促进Tenon囊成纤维细胞的增殖,并与浓度成正比。(3)2~5μg/mL decorin 能抑制TGF-β1促Tenon囊成纤维细胞增殖作用,其抑制作用与浓度成正比。结论: TGF-β1可刺激Tenon囊成纤维细胞增殖,Decorin能抑制TGF-β1促进细胞增殖的作用,其机理可能通过与TGF-β1结合抑制青光眼滤过手术后瘢痕形成。
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 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.
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 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 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.
Objective To investigate the expression of fibroblast activation protein( FAP) in mouse pulmonary fibrosis and the relationship between FAP and trarisforming growth factor β1 ( TGF-β1 ) .Methods The mouse model with pulmonary fibrosis was established by intratracheally instillation of bleomycin. The expressions of FAP, α-smooth muscle action( α-SMA) , and TGF-β1 in lung tissues were detected with immunohistochemical technique. Results There was no expression of FAP in the normal lung tissue. In the pulmonary fibrosis mice, FAP was found in the fibroblasts existed in bronchiolar adventitia or peribronchiolar ( and perivascular) connective tissue. In the fibroblast foci, the localizations of α-SMA, TGF-β1 , and FAP were similar, but the expression of FAP was more extensive than that of α-SMA and ber than that ofTGF-β1 . The degree of lung fibrosis was bly correlated with FAP, α-SMA, and TGF-β1 ( r = 0. 795,0. 766,0. 628; P lt; 0. 01) . A significantly positive correlation was also observed between TGF-β1 and FAP( r =0. 706, P lt; 0. 01) . Conclusions FAP is especially expressed in the fibroblast foci in pulmonaryfibrosis and bly correlated with the severity of pulmonary fibrosis. FAP and TGF-β1 possibly play a synergistic role in the progression of pulmonary fibrosis.
Objective To investigate the effects of caveolin-1 scaffolding domain peptide ( CSD-p)on expressions of extracellular matrix and Smads in human fetal lung fibroblasts. Methods Human fetal lung fibroblasts were cultured in vitro and divided into four groups. A control group: the cells were cultured in DMEMwithout TGF-β1 or CSD-p. A CSD-p treatment group: the cells were cultured in DMEMcontaining 5 μmol /L CSD-p. A TGF-β1 treatment group: the cells were cultured in DMEMcontaining 5 μg/L TGF-β1 .A TGF-β1 + CSD-p treatment group: the cells were cultured in DMEM containing 5 μg/L TGF-β1 and 5 μmol /L CSD-p. Caveolin -1 mRNA was detected by RT-PCR. Caveolin-1, collagen-Ⅰ, α-SMA, p-Smad2,p-Smad3 and Smad7 proteins were measured by Western blot. Results Compared with the control group,the Caveolin -1 mRNA and protein expressions in the cells of TGF-β1 group significantly reduced ( mRNA:0. 404 ±0. 027 vs. 1. 540 ±0. 262; protein: 0. 278 ±0. 054 vs. 1. 279 ±0. 085; P lt; 0. 01) , and the expression levels of collagen-Ⅰ and α-SMA proteins significantly increased ( collagen-Ⅰ: 1. 127 ±0. 078 vs.0. 234 ±0. 048; α-SMA: 1. 028 ±0. 058 vs. 0. 295 ±0. 024) . Meanwhile, the expression levels of p-Smad2 ( 1. 162 ±0. 049 vs. 0. 277 ±0. 014) and p-Smad3 proteins ( 1. 135 ±0. 057 vs. 0. 261 ±0. 046) increased with statistical significance ( P lt; 0. 01) , but the expression level of Smad7 protein significantly reduced( 0. 379 ±0. 004 vs. 1. 249 ±0. 046, P lt;0. 001) . In the CSD-p group, CSD-p had no significant effects on the expressions of above proteins compared with the control group. But in the TGF-β1 +CSD-p group, the overexpressions of collagen-Ⅰ, α-SMA, p-Smad2 and p-Smad3 induced by TGF-β1 were obviously inhibited by CSD-p ( collagen-Ⅰ: 0. 384 ±0. 040 vs. 1. 127 ±0. 078; α-SMA: 0. 471 ±0. 071 vs. 1. 127 ±0. 078;p-Smad2: 0. 618 ±0. 096 vs. 1. 162 ±0. 049; p-Smad3: 0. 461 ±0. 057 vs. 1. 135 ±0. 057; P lt; 0. 01) .Otherwise, the up-regulation of Smad7 ( 0.924 ±0. 065 vs. 0.379 ±0. 004) was found. Conclusions CSD-p can reduce fibroblast collagen-I and α-SMA protein expressions stimulated by TGF-β1 , possibly through regulation of TGF-β1 /Smads signaling pathway. It is suggested that an increase in caveolin -1 function through the use of CSD-p may be an intervention role in pulmonary fibrosis.
Objective To examine the effects of TGF-β1 on epithelial-myofibroblast transition ( EMT) of A549 cells and its relationship with extracellular regulating kinase1/2 ( ERK1/2) signaling system. Methods Cultured A549 cells were divided into one negative control group and four groups incubated with TGF-β1 for 48 hours at different concentration ( 0.05, 0. 5, 5, 10 μg/L, respectively) . The protein expressions of E-cadherin, α-smooth muscle actin ( α-SMA) , vimentin and fibronectin were assessed by indirect immunofluorescence and Western blot. In the other experiment, cultured A549 cells were incubated with TGF-β1 for different time. The protein and mRNA expressions of E-cadherin and α-SMA were assessed by Western blot and RT-PCR. The protein expressions of vimentin, fibronectin, ERK1 /2, and p-ERK1 /2 were detected by Western blot. Results By indirect immunofluorescence, Western blot, and RT-PCR analysis, E-cadherin expression significantly decreased and α-SMA expression significantly increased in A549 cells treated with TGF-β1 compared with negative controls in a time- and concentrationdependent manner ( Plt;0.05 ) . Vimentin and fibronectin protein expressions significantly increased simultaneously ( Plt;0.05) . The concentration of 5 ng/mL of TGF-β1 was most effective. The ratio of p-ERK1 /2 and ERK1/2 was significantly increased in the TGF-β1 treated cells in a time-dependent manner ( P lt;0. 05) . Conclusions TGF-β1 can induced EMT in A549 cells in vitro in a time- and concentrationdependant manner. This effect may involve in upregulation of ERK1/2 signaling system.
Objective To investigate the mechanismof lung injury caused by paraquat poisoning by observing the changes of fibrogenic cytokines in acute paraquat poisoned rats and the effects of pyrrolidine dithiocarbamate ( PDTC) . Methods Sprague-Dawley rats were randomly divided into three groups, ie. acontrol group ( n =6) , a PDTC group ( n =36) , a paraquat group ( n = 36) , and a paraquat + PDTC group( n =36) . The rats in the PDTC group, the paraquat group, and the paraquat + PDTC group were subdivided into 6 subgroups sacrificed respectively on 1st, 3rd,7th,14th, 28th and 56th day after the treatment. The levels of transforming growth factor-β1( TGF-β1 ) , platelet-derived growth factor ( PDGF) , insulin-like growthfactor-1 ( IGF-1) in serum were measured. Meanwhile the expression of connective tissue growth factor ( CTGF) and hydroxyproline in lung tissues were detected. The relationship of above cytokines with hydroxyproline was analyzed. Results The destructive phase in early ( 1 ~7 d) was characterized by hemorrhage, alveolar edema, and inflammatory cell infiltration. The proliferous phase in later stage ( 14 ~56 d) was characterized by diffused alveolar collapse with fibroblast proliferation and patchy distribution of collagen fibers. Compared with the control group, the level of TGF-β1 on all time points, the level of PDGF from7th to 56th day, the level of IGF-1 from3rd to 56th day in the paraquat group all significantly increased ( P lt;0. 01) . Immunohistochemistry results showed CTGF positive cells mainly located in aleolar epithelialcells, endothelial cells,macrophages in early stage, and fibroblasts were main positive cells on the 28th and the 56th day. The expression of CTGF in the paraquat group increased gradually compared with the control group on different time points ( P lt; 0. 05 or P lt; 0. 01) . Meanwhile, the levels of above cytokines were positively correlated with the level of hydroxyproline. Noteworthy, PDTC treatment led to significant decreases of above cytokines compared with the paraquat group in corresponding time points ( P lt;0. 05 or P lt;0. 01) .Conclusions Over expressions of IGF-1, TGF-β1 , PDGF, IGF-1 and CTGF may play important roles in lung fibrosis of paraquat poisoned rats. PDTC, as a b NF-κB inhibitor, may inhibits NF-κB activity and further significantly decreases expressions of cytokines, leading to significantly attenuated pulmonary inflammation and fibrosis. However, the mechanisms of PDTC intervention still remain to be explored.