Paclitaxel ameliorates fibrosis in hepatic stellate cells via inhibition of TGF-β/Smad activity

AIM: To investigated if paclitaxel can attenuate hepatic fi brosis in rat hepatic stellate cells (RHSCs). METHODS: RHSCs were cultured in vitro and randomly assigned to four groups: normal control group (treated only with Dulbecco's Modified Eagle's Medium), Taxol group (200 nmol/L paclitaxel was added to the cell culture), transforming growth factor (TGF)-β group (5 ng/mL recombinant human TGF-β1 was added to the cell culture), and TGF-β + Taxol group. TGF-β signaling cascade and status of various extracel...     

Hypermethylation of TGF-β1 gene promoter in gastric cancer

AIM:To examine transforming growth factor-β1(TGF-β1)promoter methylation in gastric cancer and to determine if Helicobacter pylori(H.pylori)or interleukin(IL)-1β could induce TGF-β1 hypermethylation in vitro.METHODS:We examined the frequency and extent of TGF-β1 promoter methylation using methylationspecific PCR in the gastric tissues from 47 gastric cancer patients and 39 non-gastric cancer subjects.H.pylori infection was confirmed by a positive result from either a serological test,histological analysis or C13urea breath test.GES-1 and MKN-45 cells co-cultured with H.pylori or treated with IL-1β for 12,24 and 48 h in vitro tested the effects of H.pylori or IL-1β on TGF-1β.RESULTS:Twenty-four/forty-seven(51%)cases of gastric cancer(GC)tissues showed TGF-β1 promoter methylation,15/47(31.9%)cases of matched noncancerous gastric mucosa tissues from the GC patients,and 11/39(28%)case of the normal gastric mucosa tissues from non-GC subjects showed TGF-β1 promoter methylation(51%vs 28%,P<0.05).Significantly higher levels of methylation of TGF-β1 were found in the tumor tissues than in non-tumor tissues from GC patients(0.24±0.06 vs 0.17±0.04,P<0.05)and normal gastric tissues from non-GC subjects(0.24±0.06 vs 0.15±0.03,P<0.05).TGF-β1 methylation was found in 48.3% of H.pylori-positive gastric mucosal tissues whereas only 23.1% of H.pylori-negative gastric mucosal tissues showed TGF-β1 methylation(48.3%vs 23.1%,P<0.05).IL-1β appeared to induce a dose-dependent methylation of TGF-β1 and the strongest methylation was observed in GES-1 cells treated with 2.5 ng/mL of IL-1β for 48 h.Further studies showed that pre-treatment of GES-1 cells with 20ng/mL IL-1RA for 1 h could partially abolish the effect of IL-1β on TGF-β1 methylation.Infection of GES-1cells by H.pylori was not found to induce significant TGF-β1 promoter methylation.CONCLUSION:Our data revealed that TGF-1 promoter is methylated in GC patients.IL-1β may be an important mediator for H.pylori induced gene methylation during GC     

依那普利和厄贝沙坦对肾血管性高血压大鼠颈动脉重构及转化生长因子β1/Smads表达的影响

目的观察依那普利和厄贝沙坦单用及联用对肾血管性高血压大鼠(RHR)颈动脉重构及转化生长因子β1(TGF-β1)/Smads表达的影响。方法 8～12周龄雄性Sprague-Dawley(SD)大鼠30只。建立"两肾一夹"RHR模型,设立模型组、假手术组、依那普利组[10mg/(kg·d)]、厄贝沙坦组[50mg/(kg·d)]、联合用药组[厄贝沙坦25mg/(kg·d)+依那普利5mg/(kg·d)],每组6只大鼠。药物连续干预6周。采用HE染色、Masson染色法及免疫组化染色检测颈动脉中膜形态及结构变化并测量中膜厚度、中膜厚度/腔径以及颈动脉中膜α肌动蛋白(α-actin)、增殖细胞核抗原(PCNA)、TGF-β1、磷酸化Smad2/3(p-Smad2/3)、Smad7的表达水平。结果 RHR模型组颈动脉中膜明显肥厚,平滑肌细胞体积增大,排列紊乱;中膜厚度、中膜厚度/腔径、颈动脉中膜平滑肌细胞的增殖指数及胶原纤维面积百分比均高于假手术组[中膜厚度(91.28±11.17)比(52.15±7.18)μm,中膜厚度/腔径(20.75±3.07)%比(9.94±1.52)%,增殖指数(35.31±12.97)%比(1.84±0.52)%,胶原纤维面积百分比(67.53±7.68)%比(15.35±4.47)%,均P<0.01];TGF-β1和p-Smad2/3的表达较假手术组均增多(均P<0.05),Smad7表达较假手术组减少(P<0.01)。依那普利和厄贝沙坦均能改善颈动脉平滑肌肥大和胶原沉积,减小RHR颈动脉中膜厚度、中膜厚度/腔径、平滑肌细胞的增殖指数、胶原纤维面积百分比及TGF-β1和p-Smad2/3的表达(P<0.05),增加Smad7表达(P<0.01),且两药联用较单用更能改善颈动脉重构,降低TGF-β1和p-Smad2/3的表达(P<0.05),增加Smad7表达(P<0.05)。结论依那普利和厄贝沙坦通过影响TGF-β1/Smads信号通路中TGF-β1、p-Smad2/3和Smad7的表达而改善RHR颈动脉重构,且两药联用有协同作用。     

Aberrant TGF-β1 signaling contributes to the development of primary biliary cirrhosis in murine model

AIM:To investigate whether transforming growth factor-β1(TGF-β1)signaling pathway is involved in the pathogenesis of primary biliary cirrhosis(PBC).METHODS:A murine model of PBC was developed by injection of polyinosinic polycytidylic acids(polyⅠ:C)in C57BL/6 mice,and the liver expressions of TGFβ1,TGF-βreceptorⅠ(TβRⅠ),TGF-βreceptorⅡ(TβRⅡ),p-Smad2/3,monoclonalα-smooth muscle actin antibody(α-SMA)andα1(Ⅰ)collagen in the mouse model and control mice were evaluated by immunohistochemistry,immunoblotting and real-time polymerase chain reaction(RT-PCR).Lymphocyte subsets in liver were analyzed using flow cytometry.RESULTS:The mouse model had several key phenotypic features of human PBC,including elevated levels of alkaline phosphatase,antimitochondrial antibodies,portal bile ducts inflammation,and progressive collagen deposition.Compared with control mice,protein and mRNA levels of TGFβ1,TβRⅠ,TβRⅡ,p-Smad2/3,α-SMA andα1(Ⅰ)collagen in liver(1.7±0.4 vs 8.9±1.8,0.8±0.2 vs 5.1±1.5,0.6±0.01 vs5.1±0.1,0.6±0.3 vs 2.0±0.3,0.9±0.4 vs 3.4±0.6,0.8±0.4 vs 1.7±0.3,1.1±1.2 vs 11.8±0.6,P<0.05),and the total number and percentage of CD4+CD25+FOXP3+and CD8+lymphocytes(0.01±0.001vs 0.004±0.00,0.12±0.04 vs 0.52±0.23,P<0.01)were higher in the mouse model.CONCLUSION:TGFβ1 might play a dual role in the development of PBC:it suppresses inflammatory response but operates to enhance fibrogenesis.The aberrant activity of TGF-β1 signaling contributes to the development of PBC.     

霉酚酸酯对IgA肾病大鼠肾组织中TGF-β1及Smad2/3表达的影响

目的 观察霉酚酸酯(MMF)对IgA肾病(IgAN)大鼠肾组织中转化生长因子-β1(TGF-β1),Smad2/3表达的影响,探讨MMF治疗IgAN的可能作用机制.方法 将24只雄性Wistar大鼠随机分为模型组、MMF组、对照组各8只,前两组均采用灌服牛血清白蛋白(BSA)和尾静脉注射脂多糖(LPS)的方法建立IgAN模型,其后MMF组予MMF 10 mg/(kg·d)每日灌胃1次,对照组和模型组予等量蒸馏水灌胃,持续至12周末.三组均每4周测定一次尿红细胞计数、24 h尿蛋白定量,制模成功后检测血生化指标;第12周末观察肾脏组织学改变和免疫复合物沉积情况,免疫组织化学方法检测肾组织中TGF-β1、Smad2/3的表达.结果 第6～8周末,模型组与MMF组尿红细胞计数及24 h尿蛋白定量均明显升高,与对照组相比差异有显著性(P均＜0.05);第10 ～ 12周末,MMF组尿红细胞计数及24 h尿蛋白定量均较模型组明显减少,差异有显著性(P均＜0.05);三组血生化指标无统计学差异(P均＞0.05).与对照组相比,模型组肾小球系膜细胞增生、系膜基质增多、伴弥漫性IgA沉积,TGF-β1及Smad2/3蛋白表达均明显增高(P均＜0.05);MMF组上述病理变化均明显轻于模型组、TGF-β1及Smad2/3蛋白表达均明显低于模型组(P均＜0.05).结论MMF治疗IgAN的病理机制可能是通过下调Smad2/3、TGF-β1表达发挥肾脏保护作用.     

肺心清胶囊对大鼠肺纤维化及其细胞因子TGF-β1、Smad2/3作用的实验研究

目的 观察肺心清胶囊对博来霉素所致大鼠肺纤维化的干预作用及对表达水平的影响,探讨其可能机制.方法 32只健康雄性SD大鼠,随机分为4组:空白对照组(CG),模型组(MG),强的松治疗组(DG),肺心清胶囊治疗组(EG),每组8只;除空白对照组外,其余各组采用一次性气管内滴注博莱霉素制备肺纤维化大鼠模型,CG组气管内注射等量生理盐水,DG组、EG组于造模后24小时开始给予相应的干预药物,DG、MG组给予生理盐水,分别予干预第28天处死各组动物,取左肺下叶采用HE染色及免疫组化方法观察其病理变化,检测肺组织TGF-β1,Smad2/3表达.结果 与模型组比较,肺心清胶囊治疗组的肺泡炎和肺纤维化程度明显减轻,肺组织TGF-β1、Smad2/3表达下降.结论 肺心清胶囊具有抗肺纤维化作用可能是通过TGF-β1及其信号通路Smad2/3的抑制而发挥作用.     

TGF-β1/Smad2信号通路参与海水淹溺肺损伤引起的细胞凋亡

目的探讨TGF-β1/Smad2信号通路是否参与海水淹溺肺损伤引发的细胞凋亡过程。 方法体外培养A549人肺癌细胞,用浓度为20%、40%、60%的海水进行处理,根据MTT实验结果,筛选出最适浓度的海水用于后续研究;用抑制剂SB431542预处理细胞后,再用最适浓度的海水进行处理,然后采用Real-time PCR与Western blot检测凋亡相关指标Cleaved Caspase-3的表达水平、流式细胞术与Hoechst染色观察细胞凋亡情况,同时应用Real-time PCR与Western blot对TGF-β1、Smad2和p-Smad2的表达水平进行检测。 结果随着海水浓度的增加,A549细胞的活力逐渐降低,最终选用浓度为40%的海水进行后续研究;海水处理可使细胞发生明显的凋亡现象,而抑制剂SB431542可明显恢复由海水引发的凋亡水平;同时,发现海水使TGF-β1的表达水平显著上调,抑制剂SB431542处理后这种异常上调可显著被缓解,而Smad2的表达水平无显著性变化,但海水可使p-Smad2表达水平显著上调,且抑制剂SB431542处理后p-Smad2的表达水平可明显被抑制。 结论海水淹溺肺损伤可能通过激活TGF-β1/Smad2信号通路,调节凋亡执行蛋白Caspase-3的活性,从而促使肺组织细胞发生凋亡。     

PGD2对小鼠肺成纤维细胞TGF-β1/Smads信号通路的影响

目的探讨前列腺素D2(PGD2)对小鼠肺成纤维细胞TGF-β1/Smads信号通路的影响,为哮喘气道重塑提供分子研究基础。方法采用随机分组的方法,分别采用不同浓度的PGD2受体抑制剂Laropiprant(0.3、1、3、10、30μmol/m L)不同时间(12、24、48、72、96 h)作用于肺成纤维细胞,采用MTT法检测Laropiprant对于细胞生长的抑制作用。设正常对照组、Laropiprant 0.3μmol/m L组、1μmol/m L组、3μmol/m L组、10μmol/m L组、30μmol/m L组,每组加入PGD2刺激剂TGF-β2(2.5 ng/m L)培养24 h后,再加入相应浓度的Laropiprant刺激24 h,分别用PCR法和Western blotting法检测细胞TGF-β1、Smad3以及Smad4的表达。结果加入TGF-β2(2.5 ng/m L)处理24 h后,随着Laropiprant的浓度增加,细胞TGF-β1、Smad3以及Smad4的mRNA及蛋白表达与正常对照组相比呈下降趋势(P均<0.05)。不同浓度的Laropiprant作用于细胞不同时间后,细胞生长抑制率随Laropiprant浓度增高和作用时间延长呈上升趋势,Laropiprant在浓度达到1μmol/L,作用时间为24~96 h时,细胞生长抑制率明显提高。结论L-929小鼠肺成纤维细胞中PGD2可能通过调节TGF-β1/Smads信号通路引起气道重构。