Transforming growth factor beta signal transduction

Transforming growth factor beta1 (TGF-beta1) is the prototypic member of a large family of structurally related pleiotropic-secreted cytokines that play a pivotal role in the control of differentiation, proliferation, and state of activation of many different cell types including immune cells. TGF-beta family members have potent immunosuppressor activities in vitro and in vivo. These cytokines trigger their biological effects by inducing the formation of a heteromeric transmembrane serine/threonine kinase receptor complex. These receptors then initiate intracellular signaling through activation of Smad proteins, and specific Smads become phosphorylated and associate with other Smads. These heteromeric Smad complexes accumulate in the nucleus, where they modulate the expression of target genes. Recent data support the notion that Smads are important intracellular effectors of TGF-beta in immune cells. Here, we review recent advances in TGF-beta signal transduction in immune cells.     

Transforming growth factor beta in Alzheimer''s disease.

Alzheimer's disease (AD) has been hypothesized to be an inflammatory condition. We hypothesized that anti-inflammatory cytokines, such as transforming growth factor beta (TGF-beta), counteract the inflammatory process. In the present study, we found that TGF-beta levels were elevated in both cerebrospinal fluid and serum samples obtained from AD patients < 6 h after death. Serum TGF-beta levels were also markedly elevated before death. These results suggest that elevated TGF-beta levels in AD may represent a protective host response to immunologically mediated neuronal injury.     

Transforming growth factor beta is required for differentiation of mouse mesencephalic progenitors into dopaminergic neurons in vitro and in vivo: ectopic induction in dorsal mesencephalon

Tissue engineering is a prerequisite for cell replacement as therapeutic strategy for degenerative diseases, such as Parkinson's disease. In the present study, we investigated regional identity of mesencephalic neural progenitors and characterized their development toward ventral mesencephalic dopaminergic neurons. We show that neural progenitors from ventral and dorsal mouse embryonic day 12 mesencephalon exhibit regional identity in vitro. Treatment of ventral midbrain dissociated neurospheres with transforming growth factor beta (TGF-beta) increased the number of Nurr1- and tyrosine hydroxylase (TH)-immunoreactive cells, which can be further increased when the spheres are treated with TGF-beta in combination with sonic hedgehog (Shh) and fibroblast growth factor 8 (FGF8). TGF-beta differentiation signaling is TGF-beta receptor-mediated, involving the Smad pathway, as well as the p38 mitogen-activated protein kinase pathway. In vivo, TGF-beta2/TGF-beta3 double-knockout mouse embryos revealed significantly reduced numbers of TH labeled cells in ventral mesencephalon but not in locus coeruleus. TH reduction in Tgfbeta2(-/-)/Tgfbeta3(+/-) was higher than in Tgf-beta2(+/-)/Tgf-beta3(-/-). Most importantly, TGF-beta may ectopically induce TH-immunopositive cells in dorsal mesencephalon in vitro, in a Shh- and FGF8-independent manner. Together, the results clearly demonstrate that TGF-beta2 and TGF-beta3 are essential signals for differentiation of midbrain progenitors toward neuronal fate and dopaminergic phenotype.     

Transforming growth factor beta (TGF-beta) and autoimmunity

TGF-beta1 deficient mice develop multifocal inflammatory autoimmune disease and serve as a valuable animal model of autoimmunity. Transgenic expression of a dominant negative form of TGF-beta receptor type II in T cells have enabled the study of cell lineage specific effects of TGF-beta providing clues to the potential etiology of autoimmunity. These studies suggest that TGF-beta deficiency may induce autoimmune disease by influencing a number of immunological phenomena including lymphocyte activation and differentiation, cell adhesion molecule expression, regulatory T cell function, the expression of MHC molecules and cytokines, and cell apoptosis. The spectrum of effects appears to be significant in mucosal immunity and may contribute to the pathogenesis of inflammatory bowel disease.     

转化生长因子β1对软骨组织代谢影响的研究进展*

背景：转化生长因子β1可以介导软骨合成、抑制胶原和蛋白多糖分解,在诱导软骨分化和维持软骨表型上起着重要作用,实现软骨缺损的功能性修复。 目的：从生物学特性、在生物工程中的应用、基因多态性、信号通路及微小RNA等方面综述转化生长因子β1对软骨组织代谢影响的研究进展。 方法：以“transforming growth factor-β1,Cartilage Differentiation,cartilage matrix”为英文检索词,以“转化生长因子β1,软骨分化,软骨基质”为中文检索词。经第一作者检索2007/2012CNKI数据库及SPRINGERLINK数据库有关转化生长因子β1对软骨组织代谢影响的研究进展方面的文献130篇,根据纳入排除标准保留54篇进行总结。 结果与结论：转化生长因子β1可诱导间充质细胞向软骨细胞分化,促进软骨特异性基质的合成,保护软骨基质不被各种蛋白酶水解破坏,能够增强软骨组织自身再生能力,实现使软骨的损伤逆转,在软骨修复领域展现了巨大的潜在应用价值。     

Transforming growth factor beta: an autocrine regulator of chondrocytes

Transforming growth factor beta (TGF-beta) is a ubiquitous regulator of cellular growth and differentiation. The present study investigated the effects of TGF-beta on chick growth plate chondrocyte proliferation, matrix synthesis, and alkaline phosphatase activity in short term cultures. TGF-beta markedly stimulated DNA synthesis in a dose-dependent manner, while collagen synthesis and cellular and matrix vesicle alkaline phosphatase activity were inhibited. Biologic effects of TGF-beta were correlated with binding to specific receptors, and both high and low affinity receptors were identified. Countercurrent centrifugal elutriation was used to fractionate growth plate chondrocytes to obtain populations of cells in different stages of maturation (effectively from different zones of the growth plate). TGF-beta showed increasing mitogenicity with increasing cellular maturation in the growth plate, with maximal stimulation in the proliferating and early hypertrophic cells. The smallest cells expressed only the high affinity receptor, while with hypertrophy there was increasing expression of the low affinity receptor and a progressive increase in the number of both receptors per cell. Furthermore, the dose-response curves for TGF-beta-stimulated DNA synthesis were not biphasic in the smaller cells, but became progressively more biphasic with cellular hypertrophy and expression of the low affinity receptor. Finally, TGF-beta activity was identified in partially purified chondrocyte conditioned medium by specific bioassay, indicating TGF-beta production by growth plate chondrocytes. The data suggests a potentially important autocrine function for TGF-beta in modulating chondrocyte proliferation and matrix synthesis in endochondral calcification.     

Transforming growth factor beta 1 expression in gastric carcinoma.

Many types of human malignant tumor have been reported to amplify transforming growth factor-beta 1 (TGF-beta 1) gene and overexpress its protein. However, little work has been done about the content of TGF-beta 1 protein in tissue and blood of patients with malignant tumors. TGF-beta 1 protein of tissue (n = 29) and serum TGF-beta 1 levels in patients with gastric carcinoma (n = 62) were compared with those in normal subjects (n = 10) using a TGF-beta 1 enzyme-linked immunosorbent assay. Also, expression of TGF-beta 1 mRNA (n = 20) and immunohistochemical distribution of the protein (n = 70) in gastric carcinoma tissues were studied. The immunohistochemical expression of TGF-beta 1 protein was significantly correlated with the tissue TGF-beta 1 content (r = 0.45 : p < 0.05). The content of TGF-beta 1 was 311 +/- 212 ng/g wet carcinoma tissue. TGF-beta 1 mRNA was expressed in gastric carcinoma cells. However, unexpectedly serum TGF-beta 1 levels in patients with gastric carcinoma were lower (97.1 +/- 29.4 ng/ml) than those in normal subjects (140.3 +/- 85.7 ng/ml, P < 0.05). Our results support that the tumor cells directly produce TGF-beta 1 and that semiquantitative immunohistochemical staining method for TGF-beta 1 protein is a validative method for TGF-beta 1 protein quantitation.     

Transforming growth factor beta 1 as a prognostic factor in pulmonary adenocarcinoma.

AIMS--To evaluate the efficacy of transforming growth factor beta (TGF-beta) for the prognosis of pulmonary adenocarcinoma. METHODS--TGF-beta was detected immunohistochemically using the avidin-biotin-peroxidase complex technique in resected pulmonary adenocarcinomas from 88 patients. RESULTS--Of the 88 patients, 39 were TGF-beta negative and 45 TGF-beta positive. The five year survival rate was 56% for the TGF-beta negative and 16% for the TGF-beta positive group. CONCLUSIONS--TGF-beta can be used as a prognostic factor in pulmonary adenocarcinoma.     

Transforming growth factor beta signaling: The master sculptor of fingers

Transforming growth factor beta (TGFβ) constitutes a large and evolutionarily conserved superfamily of secreted factors that play essential roles in embryonic development, cancer, tissue regeneration, and human degenerative pathology. Studies of this signaling cascade in the regulation of cellular and tissue changes in the three-dimensional context of a developing embryo have notably advanced in the understanding of the action mechanism of these growth factors. In this review, we address the role of TGFβ signaling in the developing limb, focusing on its essential function in the morphogenesis of the autopod. As we discuss in this work, modern mouse genetic experiments together with more classical embryological approaches in chick embryos, provided very valuable information concerning the role of TGFβ and Activin family members in the morphogenesis of the digits of tetrapods, including the formation of phalanxes, digital tendons, and interphalangeal joints. We emphasize the importance of the Activin and TGFβ proteins as digit inducing factors and their critical interaction with the BMP signaling to sculpt the hand and foot morphology.     

Transforming growth factor beta mediates the estrogen induced inhibition of UMR106 cell growth

A mitogenic response to transforming growth factor beta (TGF) occurred in the UMR106 cells cultured in serum-free medium and exposed serially to estradiol and TGF. This mitogenic response was lost when insulin was removed from the medium. TGF inhibited growth and increased the alkaline phosphatase content in the UMR106 cells cultured in medium lacking insulin. Prior exposure of the cells to estradiol enhanced this response. Monoclonal antibodies against TGF blocked the estradiol induced inhibition of growth after a two day incubation in medium devoid of insulin.     

大鼠皮肤创伤修复过程中转化生长因子β1和β3的表达

背景：转化生长因子β在组织创伤修复中发挥核心和关键作用。 目的：观察转化生长因子β1和转化生长因子β3在大鼠皮肤瘢痕性创伤愈合过程中表达量及表达部位的变化。 方法：制备大鼠皮肤全层切伤模型,长度1.5-2.0 cm,深及筋膜层。于伤后0 h,12 h,1 d,2 d,3 d,4 d,5 d,6 d,7 d处死大鼠,取损伤部位皮肤,采用免疫组织化学染色检测各时间点转化生长因子β1和转化生长因子β3的表达,并进行定量分析。 结果与结论：免疫组织化学染色显示,在创伤愈合的早期阶段(伤后1-5 d),转化生长因子β1和转化生长因子β3免疫阳性颗粒主要出现在上皮细胞、上皮基底层细胞胞浆、巨噬细胞等免疫细胞胞浆及肉芽组织中;随着创伤修复时间的持续,免疫阳性颗粒主要出现在真皮层的成纤维细胞及细胞外基质中。其中转化生长因子β1的表达在创伤后1-5 d最强,而转化生长因子β3在创伤后六七天时开始明显表达。可见在大鼠皮肤瘢痕性创伤愈合过程中,转化生长因子β1的表达先于转化生长因子β3,提示转化生长因子β1与胶原形成及创伤修复关系密切,而转化生长因子β3在愈合后期表达量有升高趋势,其可能与创伤后期的组织改建密切相关。     

RER+结直肠癌组织转化生长因子βⅡ型受体的突变

目的　检测转化生长因子 βⅡ型受体 (TGF βRⅡ ) (A) 10 、TGF βRⅡ (GT) 3、TGF βRⅡ 452 /454、TGF βRⅡ 53 3、hMSH3 (A) 8、hMSH6(C) 8、Bax (G) 8、胰岛素样生长因子Ⅱ型受体 (IGFⅡR) (G) 8、IGFⅡR (CT) 3 等微卫星突变热点及TGF βRⅡ点突变在RER 结直肠癌中的突变率、突变发生在肿瘤进程的哪一阶段。方法　采用聚合酶链反应 单链长度多态性分析 (PCR SSLP)、微切割 PCR SSLP、PCR 单链构象多态性分析、克隆测序、免疫组织化学对 76例结直肠癌标本进行分析。结果　RER (replicationerrorpositive)肿瘤TGF βRⅡ (A) 10 突变率约为 3 / 9,突变可发生于重度不典型增生腺瘤。其余位点未见突变。RER 结直肠癌多见于男性 ,发病年龄较早 (P <0 0 5) ;肿瘤多位于结肠 (P <0 0 5)。结论　RER 结直肠癌多见于较年轻男性 ,好发于结肠 ,仅约三分之一病例存在TGF βRⅡ(A) 10 突变 ;TGF βRⅡ (A) 10 突变发生于重度不典型增生腺瘤 ,可能对RER 腺瘤进展为癌起重要作用。RER 结直肠癌在临床病例特征上与西方发达国家的病例存在差异 ,可能有不同的发病机制     

转化生长因子β1抑制人肾小管上皮细胞的增殖

背景：慢性肾衰竭进展过程中的一个重要病理改变是炎症和纤维化,主要包括肾小球和肾小管的炎症和纤维化。目前大多数研究主要集中于肾小球,对于肾小管病变的研究相对较少。但实际上部分疾病的肾小管病变出现在肾小球病变之前,其对于疾病预后更具有指导意义。 目的：观察转化生长因子β1对人类肾小管上皮细胞HK-2增殖的影响,探索转化生长因子β1在肾小管炎症和纤维化方面的作用。 方法：将传代培养的HK-2细胞分成空白对照组和转化生长因子β1作用组,分别使用DMEM/F12培养液,以及含转化生长因子β1(2,5,10 μg/L)的DMEM/F12培养液培养,在倒置显微镜下观察各组细胞形态的改变,并使用MTT法检测细胞增殖情况。 结果与结论：转化生长因子β1能显著抑制人肾小管上皮细胞的增殖,并促使细胞向纤维样改变,与空白对照组相比差异有显著性意义(P < 0.05),其抑制增殖作用并不随转化生长因子β1质量浓度的增大而显著增强,作用时间可持续至72 h。结果可见转化生长因子β1能够抑制人肾小管上皮细胞的增殖,并具有促进肾间质纤维化的作用。     

Transforming growth factor as a marker beta of nephrogenetic disturbance in congenital obstructive uropathies

The paper presents the results of morphological and immunohistochemical studies of the kidneys and ureters obtained at surgery in 25 children aged from 2 days to 3 years who had congenital obstructive uropathies. The morphological study revealed varying renal tissue dysplasia concurrent with dysplasia of the prepelvic or distal ureter. Immunohistochemically, the kidneys showed a pronounced expression of TGFbeta1, TGF(1R1 and R2 in the nephrocytes of non-differentiated and collecting tubules, in the tubular lumen, vascular walls, in the interstitial tissue and cell interstitial infiltrates, on the hypoplastic and disoriented ureteral smooth muscle fibers. The use of the ILIAS-method to determine urinary TGF levels before and after surgery indicated a direct correlation of these indices with the degree of renal tissue dysplasia.     

转化生长因子β1与体外血管外膜成纤维细胞的增殖和迁移

背景：近年来的研究表明,血管外膜成纤维细胞在血管损伤后新生内膜的增生中起重要作用。当血管损伤后,转化生长因子β1在局部水平上调激活下游多种信号途径,其对血管外膜成纤维细胞参与新生内膜增生过程中所起的作用尚不十分清楚。 目的：观察转化生长因子β1对体外血管外膜成纤维细胞增殖和迁移的影响 方法：体外培养大鼠胸主动脉成纤维细胞,分别以0,3,5,10,15 μg/L的转化生长因子β1刺激成纤维细胞0,2,12,24,48,72 h。以MTT法检测细胞增殖活性,Transwell Chamber测试细胞迁移。 结果与结论：转化生长因子β1能诱导血管外膜成纤维细胞增殖,随着转化生长因子β1质量浓度、作用时间的增加,诱导血管外膜成纤维细胞增殖能力增强(P< 0.05),其中10 μg/L转化生长因子β1作用48 h增殖较对照组增强最为明显(P < 0.01)。不同剂量转化生长因子β1刺激后迁移的细胞数目随转化生长因子β1质量浓度增加而增加,促进作用逐渐增强,呈剂量依赖关系。