转化生长因子-β1介导的足细胞凋亡

足细胞（podocyte）,即肾小球脏层上皮细胞,直接附着在肾小球基底膜（GBM）上,是肾小球血液滤过屏障重要的细胞结构。足细胞既是免疫介导,也是非免疫介导损伤靶点,肾小球肾炎时足细胞的无序凋亡可能导致肾小球无功能的瘢痕形成。转化生长因子-β1（TGF-β1）是一种多功能的细胞因子,在损伤的肾小球内,呈典型上调。越来越多的研究表明TGF-β1介导了肾小球足细胞的凋亡,在肾小球硬化过程中发挥着重要作用。     

乳酸对肌腱细胞转化生长因子-β表达的调节作用

目的探讨乳酸对免屈趾肌腱腱鞘、腱外膜和腱内膜细胞转化生长因子（TGF）-β及其受体产生的影响。方法从兔屈趾肌腱分离腱鞘、腱外膜和腱内膜细胞并分别进行培养,在使用25mmol／L的乳酸培养后,酶联免疫吸附试验定量检测TGF-β及其受体的表达,同时应用原位杂交和免疫组织化学技术测量TGF-β的表达。结果乳酸能显著增加3种细胞所有TGF-β及其受体的表达（P〈0．05）,其中腱鞘细胞的TGF-β1和TGF-β增加值最大,腱外膜细胞的TGF-β1和TGF-β的受体增加值最大,腱内膜细胞则为TGF-β增加值最大;乳酸还显著增加3种细胞的TGF-β表达。结论乳酸能显著增加肌腱细胞的TGF-β、TGF-β受体和TGF-β mRNA的表达,因此为肌腱愈合过程中调节TGF-β水平提供新的途径。     

胎儿和少儿皮肤内转化生长因子-β1和β3基因表达的变化

目的　探讨转化生长因子 β1(TGF β1) ,TGF β3及其Ⅰ 型和Ⅱ 型受体 (TBRⅠ ,TBRⅡ )在胎儿和少儿皮肤中表达的特征。方法　提取 18例不同胎龄的胎儿皮肤和 6例少儿皮肤的总RNA后 ,分离mRNA ,用逆转录 多聚酶链反应 (RT PCR)方法检测这 4种基因的表达。结果　在早期妊娠胎儿的皮肤中 ,TGF β1,TBRⅠ和TBRⅡ基因表达较弱 ,随着胎龄的增加 ,这 3种基因表达逐渐增强。在少儿皮肤内 ,这 3种基因的表达量分别为妊娠早期皮肤的 1.3 ,1.3和 1.2倍 ,基因表达显著升高 (P <0 .0 5 )。在早期胚胎的皮肤中 ,TGF β3基因表达较强 ,而在少儿皮肤内 ,该基因表达低下。结论　在早期胚胎皮肤中 ,TGF β1,TBRⅠ和TBRⅡ基因低表达 ,TGF β3基因的高表达可能与胎儿皮肤创面无瘢痕修复密切相关。     

转化生长因子-β_1对前列腺基质细胞基因表达的调节作用

目的　探讨转化生长因子 β1(TGF β1)对前列腺基质细胞基因表达的调节作用。　方法　原代培养人前列腺基质细胞 ,并传代至 4～ 6代。分别将浓度为 0 .0 1、0 .10、1.0 0、10 .0 0 μg/L的TGF β1加入细胞培养液中。孵育 48h后收集细胞。用内参照半定量RT PCR方法检测前列腺基质细胞雄激素受体 (AR)、TGF β1、bFGF和平滑肌特异性标记蛋白smoothelin基因的转录水平。　结果　与对照组相比 ,低浓度 (0 .0 1μg/L)的TGF β1可增强体外培养的前列腺基质细胞内AR表达 (P <0 .0 1) ,差别有显著性意义。随TGF β1浓度增加 ,促AR表达作用减弱。随TGF β1浓度增加基质细胞TGF β1、bFGF和smoothelin基因的转录增加 (P <0 .0 1) ,并且随着应用浓度增加促各基因转录的作用增强。　结论　TGF β1对前列腺基质细胞基因表达具有广泛的调节作用 ,在前列腺增生发病中具有重要作用     

孕激素调节人成有细胞转化生长因子—β1、β2的表达

目的　研究孕激素对正常成人成骨细胞转化生长因子 (TGF) β1、TGF β2表达的调节作用 ,探讨孕激素治疗绝经后骨质疏松症 (OP)的作用机制。方法　鉴定成人成骨细胞 (hOB) ,测定碱性磷酸酶 (ALP)活性、骨钙素分泌 ,VanGieson氏苦味酸酸性复红染色法进行Ⅰ型胶原染色。hOB用孕酮干预。Northern杂交、ELISA分别检测hOBTGF β1、TGF β2mRNA和蛋白质分泌。结果　观察到hOB分泌的ALP活性为 (74 3± 4 7)mU/mg蛋白 ,培养上清液骨钙素含量为 (3 84± 0 3 9)ng/ml蛋白 ,Ⅰ型胶原染色呈红色。观察到孕酮增强hOBTGF β1、TGF β2mRNA表达呈剂量依赖性 (P <0 0 0 1) ;10 -9mol/L孕酮诱导 12～ 2 4h促进TGF β1、TGF β2mRNA表达 ,呈时间依从性。孕酮促进hOBTGF β1、TGF β2蛋白质分泌呈剂量依赖性 (P <0 0 0 1) ;10 -9mol/L孕酮诱导 12～ 2 4h促进TGF β1、TGF β2蛋白质分泌 ,呈时间依从性。结论　孕激素可能通过诱导成骨细胞TGF β1、TGF β2表达 ,促进成骨细胞增殖与分化 ,增强成骨功能及骨基质合成 ,促进骨形成     

转化生长因子-β1与IgA肾病

转化生长因子β(transforming growth factor β,TGF-β)是由Assoian等[1]首次从血小板中提取出来的,它是一类多功能的细胞生长因子,能够抑制多类细胞的增殖、分化、促进细胞间质的形成.IgA肾病又称Berger's病,是以肾小球系膜区IgA免疫复合物沉积为特征的一类肾小球肾炎,病理改变以系膜增殖为基本组织学改变,临床上以血尿为主要表现.我国为IgA肾病高发地区,约占原发性肾小球肾炎的26%～34%,其预后较差,在确诊后5～25年内约20%～40%的患者发展为终末期肾脏疾病,这些引起了国内外学者的广泛关注,近年来发现TGF-β1的表达在IgA肾病中显著增高,与IgA肾病的转归密切相关.现将这一领域的有关研究进展作一概要综述.     

阻断转化生长因子-β受体信号转导降低瘢痕疙瘩细胞转化生长因子-β1自分泌的研究

目的 研究瘢痕疙瘩成纤维细胞转化生长因子－β1（TGF－β1）的自分泌现象和阻断TGF－β受体信号转导对TGF－β1自分泌的调控。方法 组织块法体外培养瘢痕疾疙瘩成纤维细胞，加入重组人源（rh）TGF－β1（5mg/L）或含缩短型TGF－βⅡ型体的重组腺病毒（50pfu/cell），并用Northern印迹观察它们对TGF－β1极其Ⅰ、Ⅱ型受体的基因调控。结果 rhTGF－β1能上调TGF－β1（30％－50％）和Ⅰ型受体（30％－90％）的基因表达，但不影响Ⅱ型受体的基因表达。短型TGF－βⅡ型受体在瘢痕疙瘩细胞的过度表达减少细胞TGF－β1（50％－65％）和Ⅰ型受体（21％－55％）的基因表达，但不影响Ⅱ型受体的基因表达。结论 瘢痕疙瘩细胞存在TGF－β1的自分泌现象，而缩短型TGF－βⅡ型受体的过度表达可以通过阻断TGF－β的信号转导来降低TGF－β1的自分泌。     

结缔组织生长因子介导转化生长因子β1促进瘢痕成纤维细胞转分化的研究

目的 了解结缔组织生长因子(CTGF)介导TGF-β1发挥促人增生性瘢痕Fb(HSFb)转分化的作用.方法 体外培养人HSFb,取5份细胞标本分别加入不同浓度TGF-β1(0、2.5、5.0、7.5、10.0 ng/mL),作用48 h后待测.余下标本分为:空白对照组;CTGF刺激组,培养液中加入终浓度10.0 ng/mL重组人CTGF;TGF-β1刺激组,培养液中加入终浓度10.0 ng/mL重组人TGF-β1;CTGF反义寡脱氧核苷酸(ASODN)转染组,细胞转染CTGF ASODN后,加入培养液;CTGF ASODN转染+TGF-β1刺激组,细胞转染CTGF ASODN后2 h,加人含终浓度10.0 ng/mL重组人TGF-β1的培养液.蛋白质印迹法分析不同浓度TGF-β1刺激对细胞CTGF表达的影响,比较各组α-平滑肌肌动蛋白(α-SMA)表达变化;流式细胞仪检测α-SMA阳性细胞百分率.结果 TGF-β1浓度为10.0 ng/mL时,CTGF的表达明显高于未受刺激的细胞(P<0.05).CTGF刺激组与TGF-β1刺激组α-SMA表达明显高于空白对照组(P<0.01).CTGF ASODN转染组以及CTGF ASODN转染+TGF-β1刺激组α-SMA表达与空白对照组接近(P>0.05).上述各组细胞α-SMA阳性细胞百分率依次为(10.8±2.8)%、(29.1±4.0)%、(28.7±4.8)%、(10.7±2.3)%、(14.3±2.9)%,统计学分析结果类似于α-SMA表达.结论 CTGF是TGF-β1发挥促人HSFb转分化的重要下游效应分子之一.     

转化生长因子β激活激酶1介导的细胞自噬在小鼠脑缺血-再灌注损伤中的作用

目的评价转化生长因子β激活激酶1(TGFβ-activated kinase-1,TAK1)介导的细胞自噬在小鼠脑缺血-再灌注(ischemia-reperfusion,IR)损伤中的作用。方法雄性昆明小鼠72只,8周龄,体重(25.0±3.5)g,采用随机数字表法分为六组:空白对照组(C组)、假手术组(S组)、IR组、TAK1短发夹RNA(shRNA)慢病毒组(T组)、阴性对照慢病毒组(Y组)和生理盐水组(NS组),每组12只。T组、Y组和NS组分别以1μl/min侧脑室注射TAK1shRNA慢病毒、阴性对照慢病毒和等量生理盐水10μl。2周后IR组、T组、Y组和NS组制备脑IR损伤模型,缺血2h后恢复灌注;S组分离颈总动脉但不夹闭,其余手术步骤同IR组。再灌注24h后进行神经功能缺陷评分(neurological severity scores,NSS);NSS评分完成后处死小鼠,取脑组织测定脑梗死体积;Western blot法检测小鼠脑组织TAK1、LC3Ⅱ/LC3Ⅰ、Beclin1和p62蛋白含量。结果 IR组、T组、Y组和NS组NSS评分和脑梗死体积百分比明显高于C组(P0.05);T组NSS评分和脑梗死体积百分比明显低于IR组(P0.05)。IR组、Y组和NS组脑组织TAK1蛋白含量明显高于C组(P0.05);T组脑组织TAK1蛋白含量明显低于IR组(P0.05)。IR组、T组、Y组和NS组LC3Ⅱ/LC3Ⅰ比值、Beclin1蛋白含量明显高于C组(P0.05),p62蛋白含量明显低于C组(P0.05);T组脑组织LC3Ⅱ/LC3Ⅰ比值、Beclin1蛋白含量明显低于,p62蛋白含量明显高于IR组(P0.05)。结论 TAK1介导的细胞自噬参与小鼠脑缺血-再灌注损伤机制。     

椎间盘内注射转化生长因子-β1诱导椎间盘退变

目的探讨转化生长因子-β1（transforming growth factorial,TGF-β1）对正常成年的羊椎间盘组织内环境的影响。方法将TGF-β1注射进羊的椎间盘内,生理盐水和碱性成纤维细胞生长因子（basic fibroblast growing factor,bFGF）分别作为阴性和阳性对照。术前及术后2．4．6个月检查腰椎X线及MRI,观察影像学变化;术后6个月处死动物,取出完整的椎间盘组织,观察椎间盘组织学变化。结果羊L5／L6椎间盘在注射转化生长因子6个月后（与对照组相比较）即出现明显退变。结论外源性TGF-β1可以导致正常椎间盘的退变。     

Blocking transforming growth factor-beta receptor signaling down-regulates transforming growth factor-beta1 autoproduction in keloid fibroblasts.

OBJECTIVE: To study transforming growth factor-beta1 (TGF-beta1) autoproduction in keloid fibroblasts and the regulation effect of blocking TGF-beta intracellular signaling on rhTGF-beta1 autoproduction. METHODS: Keloid fibroblasts cultured in vitro were treated with either rhTGF-beta1 (5 ng/ml) or recombinant adenovirus containing a truncated type II TGF-beta receptor gene (50 pfu/cell). Their effects of regulating gene expression of TGF-beta1 and its receptor I and II were observed with Northern blot. RESULTS: rhTGF-beta1 up-regulated the gene expression of TGF-beta1 and receptor I, but not receptor II. Over-expression of the truncated receptor II down-regulated the gene expression of TGF-beta1 and its receptor I, but not receptor II. CONCLUSIONS: TGF-beta1 autoproduction was observed in keloid fibroblasts. Over-expression of the truncated TGFbeta receptor II decreased TGF-beta1 autoproduction via blocking TGF-beta receptor signaling.     

Rapamycin induces transforming growth factor-beta production by lymphocytes

BACKGROUND: Under certain conditions rapamycin and transforming growth factor- (TGF) beta have similar immunoregulatory effects, suggesting a potential functional link between rapamycin and TGF-beta. METHODS: Splenic leukocytes were stimulated in vitro with anti-CD3 or with allogeneic cells in vivo in the presence or absence of rapamycin. TGF-beta production by activated lymphocytes was quantitated using ELISA. RESULTS: Splenic leukocytes from BALB/c mice that were primed with allogeneic cells and conditioned with rapamycin in vivo as well as splenic leukocytes that were treated with rapamycin in vitro produced significantly higher levels of TGF-beta upon anti-CD3 stimulation as compared with untreated controls. CONCLUSION: Our data suggest that rapamycin can program activated lymphocytes to produce TGF-beta. Thus, the immunosuppressive effects of rapamycin may be partially mediated by TGF-beta.     

Macrophage-derived transforming growth factor-beta1 induces hepatocellular injury via apoptosis in rat severe acute pancreatitis

BACKGROUND: The mechanism of acute pancreatitis-induced hepatocellular injury is unclear. We have observed hepatocyte apoptosis in rat acute necrotizing pancreatitis. These studies were designed to determine the mediator(s) responsible for hepatocyte apoptosis and to clarify the significance of macrophages as its source. METHODS: A rat sodium deoxycholate-induced pancreatitis model was used. Immunohistochemical studies for apoptosis-inducing mediators on hepatocytes were examined in the liver and on the peritoneal macrophages. The levels of transforming growth factor-beta1 (TGF-beta1) were also evaluated quantitatively with an enzyme-linked immunosorbent assay. Induction of apoptosis on the hepatocytes was evaluated by in situ nick-end labeling and tissue DNA fragmentation enzyme-linked immunosorbent assay. Finally, the effects of TGF-beta1 neutralization and macrophage depletion were examined. RESULTS: In the liver and the peritoneal macrophages, strong expression of TGF-beta1 was detected early in the course of pancreatitis. In sodium deoxycholate-induced pancreatitis, the levels of TGF-beta1 were also elevated in the plasma (9.2 +/- 0.8 ng/mL), in the pancreatitis-associated ascitic fluid (11.5 +/- 0.6 ng/mL), and in the liver homogenate (2.8 +/- 0.3 ng/g of liver tissue). Moreover, the amount of fragmented DNA of the liver with pancreatitis was 290% +/- 20% of that with a sham operation and serum alanine aminotransferase levels elevated to 248.2 +/- 67.0 IU/L. TGF-beta1 neutralization partly blocked the positive labeling on the nuclei of the hepatocytes, the elevation of the amounts of fragmented DNA (205% +/- 10% of sham operation), and the serum alanine aminotransferase level (144.2 +/- 14.9 IU/L). On the other hand, the macrophage depletion caused a marked decrease in the TGF-beta1 protein level in the plasma (4.8 +/- 1.2 ng/mL) or in the pancreatitis-associated ascitic fluid (8.0 +/- 1.0 ng/mL). Moreover, the macrophage depletion completely inhibited the elevation of the TGF-beta1 protein level in the liver homogenate (1.5 +/- 0.4 ng/g of liver tissue), and thereafter decreased the amounts of the positive labeling on the nuclei of the hepatocytes and decreased the amount of fragmented DNA (120% +/- 18% of sham operation) and the serum alanine aminotransferase elevation (119.2 +/- 24.2 IU/L). CONCLUSIONS: In a model of sodium deoxycholate-induced pancreatitis, macrophages are responsible for pancreatitis-induced hepatocellular injury by means of apoptosis, and macrophage-derived TGF-beta1 is one of the major factors inducing the hepatocyte apoptosis.     

Survival of mitomycin C-treated pancreatic islet xenografts is mediated by increased expression of transforming growth factor-beta

BACKGROUND: Mitomycin C (MMC) can trigger various intracellular signals. The authors previously showed that pretreatment of highly immunogenic crude pancreatic islets with MMC improved their survival in a rat-to-mouse transplantation model. The aim of this study was to investigate the role of transforming growth factor (TGF)-beta in mediating MMC-induced survival of islet xenografts. METHODS.: Collagenase-digested islets obtained from WS rats (RT1k) were incubated for 30 min with 10 microg/mL MMC and then transplanted into streptozotocin-induced diabetic C57BL/6 (H-2b) mice after 20 hr of culture at 37 degrees C. RESULTS: Survival of xenografts was enhanced by pretreatment of islets with MMC. MMC-treated xenografts showed a mild inflammatory cell response and significantly minimal infiltration of macrophages, CD4 T cells, and CD8 T cells compared with untreated grafts. TGF-beta mRNA was increased at 20 hr after MMC treatment, and TGF-beta protein expression was also increased compared with untreated islet xenografts. TGF-beta concentration in blebs formed around the xenografts (but not in the serum) was higher in animals that underwent transplantation with MMC-treated islets than with untreated islets. Simultaneous transplantation of MMC-treated and untreated islets separately in each kidney of recipient mice showed that protection was only found in MMC-treated islets. Treatment of islets before transplantation by neutralizing anti-TGF-beta antibody suppressed the MMC-protective effects on graft survival, whereas no such effect was noted with isotype-matched immunoglobulin. CONCLUSIONS.: The authors' results indicate that MMC treatment effectively reduces local inflammatory response and that such effects are mediated by increase of TGF-beta during the early period of islet transplantation.     

TGF-β1与腱病关系的研究进展

腱病是常见的软组织疾病,但其发病机制尚未阐明并缺乏有效治疗手段。组织纤维化改变是其最主要的病理学特点之一。转化生长因子β1(transforming growth factor-beta1,TGF-β1)是参与纤维化的重要因子,它在腱病组织中的表达并不一致,仍存在争议。但绝大多数研究显示TGF-β1有异常表达,且以升高为主,表明TGF-β1在腱病发病过程中起重要作用。在肌腱的损伤和修复过程中,TGF-β1增高的时间点并不一致,其在肌腱修复中发挥作用的时间目前尚无定论。因TGF-β1在肌腱腱病和肌腱修复这两个看似相反的过程中都有异常表达,所以推测它并非一种单向调节的因子,而是具有多效性的。目前研究认为TGF-β1的作用途径是TGF-β1与受体相结合,将信号传入细胞,现在发现其受体有3种。TGF-β1在细胞内信号传导的经典通路主要是通过激活Smad通路进行的,同时也存在一些非经典通路。TGF-β1可以打破细胞外基质的平衡,这可能是造成腱病的一个途径,但其对细胞外基质的调控是复杂且多样的,需要深入研究。现有研究显示,阻断TGF-β1的下游通路对改善腱病的作用不佳,因此可以尝试对TGF-β1产生的上游机制进行研究,从寻找TGF-β1产生源头出发,或许可以找到更好的抑制腱病发生发展的新靶点。     

Increased expression of transforming growth factor-beta1 in patellar tendinosis

Patellar tendinosis is characterized by longstanding localized and activity-related pain, swelling and tenderness on palpation, and characteristic features on magnetic resonance imaging and ultrasonography and during surgical excision. Histologic examination of tendinosis tissues shows disrupted collagen matrix, increased cellularity, and increased proteoglycan stainability, but lack of inflammatory cell infiltration despite the clinical signs resembling inflammation. Disturbances in inflammatory response may be associated with the development of tendinosis. Expression of cyclooxygenase-2 and transforming growth factor-beta1 were detected in tendinosis, and the in vitro production of prostaglandin E2 by tendinosis and healthy tendon fibroblast cultures also was observed. Eleven patients with patellar tendinosis and 12 control subjects with healthy patellar tendons, but deficient anterior cruciate ligaments, were included in the current study. The percentages of immunopositive cells in tendinosis samples for cyclooxygenase-2 and transforming growth factor-beta1 were 66.75 and 56.40, respectively, which were significantly higher than those of the control subjects (25.15 and 23.06 respectively). Tendinosis fibroblast culture also produced more prostaglandin E2 and active transforming growth factor-beta1. These findings indicate the involvement of prostaglandins and cytokines that may explain the clinical symptoms and nonhealing features of tendinosis.