TGF-β2与妊娠期高血压疾病

妊娠期间母胎界面存在着复杂的免疫调控关系,蜕膜及绒毛作为母体及胎儿的直接接触面,是发生免疫反应的重要部位。多种细胞因子如转化生长因子-β、肿瘤坏死因子-α及血管内皮细胞等具有营养细胞、调控滋养细胞侵入、免疫抑制、防止母胎排斥等多种功能,他们在正常妊娠的维持中起着重要的作用。目前转化生长因子-β2的作用已越来越受重视,本文将从转化生长因子-β2与妊娠期高血压疾病存在的关系作如下综述。     

TGF-β1受体1和2在TGF-β1调节细胞增殖中的作用

转化生长因子β1(transforming growth factor-β1,TGF-β1)是一种多功能细胞因子,在细胞增殖、分化、伤口愈合和肿瘤生成转移等过程中均发挥重要调控作用。TGF-β1对细胞增殖的调节可因细胞类型、刺激剂量不同而不同,但其差异调节的机制还不清楚。现普遍认为,TGF-β1在TGFBR2/TGFBR1二聚体参与下通过经典的Smad信号通路抑制增殖,而通过非Smad信号通路促进细胞周期,但是机体是如何调控这种不同增殖调节作用转化的还不明确。TGFBR1和TGFBR2在细胞中的分布和比例变化可能是TGF-β1差异性调控细胞增殖作用的一个重要机制。     

TGF-β2 antagonizes IL-6-promoted cell survival

Molecular and Cellular Biochemistry - Hepatocellular carcinoma (HCC) is one of leading causes of cancer-related death, and its increasing incidence worldwide is a cause for concern. The recombinant...     

Separation, purification, and sequence identification of TGF-β1 and TGF-β2 from bovine milk

Cox and Bürk (Eur. J. Biochem., 1991) reported the partial characterization of Milk Growth Factor (MGF) which stimulated the migration of fibroblasts. We have fractionated the partially purified sample by RP-HPLC and obtained the separation of two peaks of activity. The two active components were isolated as pure MGF-a and MGF-b by RP-HPLC and preparative SDS-PAGE. The purified MGF-a, consisting of a single band by gel electrophoresis and a single peak on an HPLC reversed-phase C-4 column, has the same specific activity as TGF-2 in the fibroblast migration assay. MGF-a was digested by endoprotease Asp-N and the cleaved peptides were analyzed by Edman degradation and plasma desorption mass spectrometry (PDMS). The whole sequence of MGF-a determined by automated sequenator and PDMS of S-pyridylethylated protein and selected fragments was found to be identical to that of TGF-2. MGF-b protein mixture separated by SDS-PAGE was electrophoretically transferred onto a Biometra Glassybond membrane, and the blotted MGF-b protein was directly sequenced on an automated sequenator. The identified 29 amino acids sequence of MGF-b was identical to the amino-terminal sequence of TGF-1. Our study demonstrates that MGF is composed of both TGF-1 and TGF-2. TGF-2 (85%) is the predominant form.     

Latent TGF-β-binding proteins

The LTBPs (or latent transforming growth factor β binding proteins) are important components of the extracellular matrix (ECM) that interact with fibrillin microfibrils and have a number of different roles in microfibril biology. There are four LTBPs isoforms in the human genome (LTBP-1, − 2, − 3, and − 4), all of which appear to associate with fibrillin and the biology of each isoform is reviewed here.The LTBPs were first identified as forming latent complexes with TGFβ by covalently binding the TGFβ propeptide (LAP) via disulfide bonds in the endoplasmic reticulum. LAP in turn is cleaved from the mature TGFβ precursor in the trans-golgi network but LAP and TGFβ remain strongly bound through non-covalent interactions. LAP, TGFβ, and LTBP together form the large latent complex (LLC). LTBPs were originally thought to primarily play a role in maintaining TGFβ latency and targeting the latent growth factor to the extracellular matrix (ECM), but it has also been shown that LTBP-1 participates in TGFβ activation by integrins and may also regulate activation by proteases and other factors. LTBP-3 appears to have a role in skeletal formation including tooth development. As well as having important functions in TGFβ regulation, TGFβ-independent activities have recently been identified for LTBP-2 and LTBP-4 in stabilizing microfibril bundles and regulating elastic fiber assembly.     

β3 Integrin Promotes TGF-β1/H2O2/HOCl-Mediated Induction of Metastatic Phenotype of Hepatocellular Carcinoma Cells by Enhancing TGF-β1 Signaling

In addition to being an important mediator of migration and invasion of tumor cells, β3 integrin can also enhance TGF-β1 signaling. However, it is not known whether β3 might influence the induction of metastatic phenotype of tumor cells, especially non-metastatic tumor cells which express low level of β3. Here we report that H₂O₂ and HOCl, the reactive oxygen species produced by neutrophils, could cooperate with TGF-β1 to induce metastatic phenotype of non-metastatic hepatocellular carcinoma (HCC) cells. TGF-β1/H₂O₂/HOCl, but not TGF-β1 or H₂O₂/HOCl, induced β3 expression by triggering the enhanced activation of p38 MAPK. Intriguingly, β3 in turn promoted TGF-β1/H₂O₂/HOCl-mediated induction of metastatic phenotype of HCC cells by enhancing TGF-β1 signaling. β3 promoted TGF-β1/H₂O₂/HOCl-induced expression of itself via positive feed-back effect on p38 MAPK activation, and also promoted TGF-β1/H₂O₂/HOCl-induced expression of α3 and SNAI2 by enhancing the activation of ERK pathway, thus resulting in higher invasive capacity of HCC cells. By enhancing MAPK activation, β3 enabled TGF-β1 to augment the promoting effect of H₂O₂/HOCl on anoikis-resistance of HCC cells. TGF-β1/H₂O₂/HOCl-induced metastatic phenotype was sufficient for HCC cells to extravasate from circulation and form metastatic foci in an experimental metastasis model in nude mice. Inhibiting the function of β3 could suppress or abrogate the promoting effects of TGF-β1/H₂O₂/HOCl on invasive capacity, anoikis-resistance, and extravasation of HCC cells. These results suggest that β3 could function as a modulator to promote TGF-β1/H₂O₂/HOCl-mediated induction of metastatic phenotype of non-metastatic tumor cells, and that targeting β3 might be a potential approach in preventing the induction of metastatic phenotype of non-metastatic tumor cells.     

TGF-β2和TGFβRⅡ在外阴鳞癌中的表达及意义

目的:探讨外阴鳞癌(VSCC)中转化生长因子-β2(TGF-β2)和转化生长因子受体βRⅡ(TGFβRⅡ)蛋白的表达及其临床病理意义。方法:收集30例外阴鳞癌及10例外阴整形时切下的外阴正常皮肤组织。所有组织来自2012年1月至2015年10月在我院妇科行手术治疗的患者。采用免疫组化方法检测TGF-β2及TGFβRⅡ蛋白的表达。结果:外阴鳞癌组织中TGF-β2的阳性表达率显著高于正常外阴组织(90%vs 20%),差异有统计学意义(P0.05),TGF-β2的表达与肿瘤分化程度、FIGO分期无关(P0.05),但与淋巴结是否转移显著相关(P0.05)。外阴鳞癌组织中TGFβRⅡ的阳性表达低于正常外阴组织(13.33%vs 70%),差异有统计学意义(P0.05),TGFβRⅡ的表达与肿瘤分化程度、FIGO分期和淋巴结是否转移均无显著相关性(P0.05)。结论:TGF-β2的表达上调与外阴鳞癌的发生及其淋巴结转移有关,可能是VSCC的治疗靶点。TGFβRⅡ的表达下调可能参与了外阴鳞癌的发生。     

TGF-β2 increases cell-cell communication in chondrocytes via p-Smad3 signalling

Connexin 43 (Cx43)-mediated gap junction intercellular communication (GJIC) plays a crucial role in the pathology and physiology of joint tissues. Transforming growth factor-β2 (TGF-β2), one of the potent regulatory factors in chondrocytes, plays a key role in the regulation of cell cycle and development of joint diseases. However, it is still unknown how TGF-β2 mediates GJIC in chondrocytes. The aim of this study was to explore the potential mechanism by which TGF-β2 regulates GJIC in chondrocytes. CCK-8 assays and scratch assays were performed to define the role of TGF-β2 on cell proliferation and migration. The scrape loading/dye transfer assay and scanning electron microscopy (SEM) were used to verify the effect of TGF-β2 on GJIC between chondrocytes. qPCR was performed to analyse the expression of genes in the gap junction protein family in chondrocytes. The expression of the Cx43 protein and phosphorylated Smad3 (p-Smad3) was evaluated by western blot assay. Immunofluorescence staining was used to explore p-Smad3 signalling pathway activation and Cx43 distribution. From these experiments, we found that the Cx43 protein was the most highly expressed member of the gap junction protein family in chondrocytes. We also found that TGF-β2 facilitated cell-to-cell communication in chondrocytes by upregulating Cx43 expression in chondrocytes. Finally, we found that TGF-β2 activated Smad3 signalling and promoted the nuclear aggregation of p-Smad3. Inhibition experiments by SIS3 also confirmed that TGF-β2-mediated GJIC through p-Smad3 signalling. For the first time, this study confirmed that TGF-β2 could regulate the formation of Cx43-mediated GJIC in chondrocytes via the canonical p-Smad3 signalling pathway.     

TGF-β1 stimulates movement of renal proximal tubular epithelial cells in a three-dimensional cell culture via an autocrine TGF-β2 production

TGF-βs are multifunctional cytokines, but their roles in human renal homeostasis are not fully understood. This study investigated the role of TGF-β1 in the movement of human renal proximal tubular epithelial cells (PTECs) in a three-dimensional (3D) model. HKC-8 cells, a human PTEC line, were grown in a 3D collagen culture system. Cell movement was observed under a microscope. The gene expression was examined using PCR Arrays or qRT-PCR, and protein levels by Western blot. Here, we showed that the tight junction structure formed between adjacent cells of a HKC-8 cell colony in 3D cultures, and TGF-β1 stimulated their movement, evidenced by the appearance of fingerlike pseudopodia in the leader cells at the edge of the colonies. The cell movement of these human PTECs was correlated with up-regulation of both MMP2 and MMP9 and down-regulation or inactivation of PLAUR and PTK2B. Analysis of TGF-β signaling targets confirmed autocrine production of TGF-β2 and its cleaving enzyme furin as well as SNAI1 by TGF-β1stimulation. Knockdown of TGF-β2 expression disrupted TGF-β1-stimulated PTEC invasiveness, which was correlated with the down-regulation of MMP2 and MMP9. In conclusion, the activation of TGF-β receptor autocrine signaling by up-regulated TGF-β2 may play a pivotal role in TGF-β1-induced human PTEC movement, which could be mediated at least by both MMP2 and MMP9.     

The linker region of Smad2 mediates TGF-β-dependent ERK2-induced collagen synthesis

Transforming growth factor (TGF)-β1 can cause fibrosis diseases by enhancing production of collagen. However, the intracellular signaling mechanism for TGF-β1 stimulation of this process has not been fully elucidated. The present study focused on this mechanism and the cross-talk between the MAPK and Smad pathways. Extracellular signal-regulated kinase (ERK)2 ablation by a small interfering RNA led to marked inhibition of TGF-β1-induced collagen synthesis and enhanced phosphorylation of the Smad2 linker site in NIH/3T3 fibroblast cells. However, ERK1 ablation had minimal effects. Ablation of either ERK2 or ERK1 had no effect on the phosphorylation of the Smad2 C-terminal site. Furthermore, a Smad2 mutant with reduced phosphorylation of the Smad2 linker site inhibited TGF-β1-induced collagen synthesis. These results indicate that ERK2, rather than ERK1, plays a predominantly positive role in TGF-β1-induced collagen synthesis, and that ERK2 enhances collagen synthesis, at least partially, through activation of the Smad2 linker site.     

Dynamics of TGF-β/Smad signaling

The physiological responses to TGF-β stimulation are diverse and vary amongst different cell types and environmental conditions. Even though the principal molecular components of the canonical and the non-canonical TGF-β signaling pathways have been largely identified, the mechanism that underlies the well-established context dependent physiological responses remains a mystery. Understanding how the components of TGF-β signaling function as a system and how this system functions in the context of the global cellular regulatory network requires a more quantitative and systematic approach. Here, we review the recent progress in understanding TGF-β biology using integration of mathematical modeling and quantitative experimental analysis. These studies reveal many interesting dynamics of TGF-β signaling and how cells quantitatively decode variable doses of TGF-β stimulation.     

TGF-α、TGF-β1在胰腺癌中的表达及临床意义

目的:研究TGF-α、TGF-β1与胰腺癌临床病理的关系.方法:免疫组织化学SABC法检测41例胰腺癌组织和12例正常胰腺组织中TGF-α、TGF-β1的表达情况,并分析其与病人的年龄、性别、肿瘤部位、病理分级和分期(UICC)等指标的相关性.结果:在41例胰腺癌组织中TGF-αTGF-β1的阳性表达率分别为73.2%、63.4%,在12例正常胰腺组织中的阳性表达率分别为16.7%、25.0%,两组之间存在显著差异(P=0.001).在胰腺癌组织中,TGF-β1的表达在不同分期中存在显著差异(P=0.019);TGF-α的表达与胰腺癌患者的年龄、性别、肿瘤部位、大小、分期及组织学分级无相关性(P>0.05).结论:TGF-α、TGF-β1在胰腺癌中高表达.TGF-β1与胰腺癌病理分期有关.     

TGF-β在小鼠胎盘中的表达

利用原位杂交和免疫组化的方法对小鼠胎盘中的TGF-β（transform growth factor-β)mRNA和蛋白质进行检测,结果显示：在妊娠第7.5-9.5天,TGF-β主要在子宫蜕膜中表达,而且表达逐渐增强。说明这一时期TGF-β的作用主要是控制滋养层细胞的侵入,这种控制是通过对PA（plasminogenin activotor)和MMP（matrix metalloproteinase)两类主要的细胞外蛋白水解酶的抑制作用来实现的,到妊娠10.5天时,滋养层巨细胞明显表达TGF-βmRNA和蛋白质,这与其功能的转换是一致的,因为此时的滋养层巨细胞体积变大。停止增殖,其功能也从侵入型向内分泌型转换。海绵滋养层细胞从第9.5天开始表达TGF-βmRNA,而TGF-β抗原从第10.5天开始出现,第11.5-12.5天,TGF-βmRNA的表达达到最高,此时的TGF-β的作用是调控胎儿血管的形成,另外,TGF-β对免疫系统有强烈的抑制作用,妊娠中后期海绵滋养层细胞可能通过大量表达TGF-β以调节局部免疫,避免母体对胎儿的免疫排斥。     

胚胎癌细胞中TGF-β样生长因子

先后用Bio-Gel P 10和HPLC分离、纯化小鼠F 9-3 EC细胞瘤组织的酸/乙醇提取物,得到分子量为15 kDa的纯制品,不仅在EGF存在时,可以诱使NRK 49 F细胞在软琼脂层形成集落和刺激其DNA合成,而且还??能单独抑制CCL/64细胞的生长。此外,这种15 kDa分子能与抗人。TGF-β_1分子N末端1-29氨基酸残基合成多肽抗体起交叉免疫反应,表明两者在分子结构上有一些共同的抗原决定簇。我们认为F 9-3 EC细胞来源的15 kDa分子是属于TGF-β样性质的一类生长因子。     

TGF-β在前列腺癌骨转移中的研究进展

进展期前列腺癌多会发生骨转移,导致患者骨质破坏甚至死亡。前列腺癌发生骨转移的机制目前尚未研究清楚。既往多认为是因为前列腺癌细胞表面携带者容易在骨环境中生长的表型。但是目前多认为是肿瘤细胞与骨骼微环境之间的相互作用导致的结果。它们之间是通过细胞因子来传递信息。在众多因子中,TGF-β对前列腺癌骨转移灶中的各种细胞都起着重要作用。研究表明在体外实验中TGF-β的作用极易受到细胞生长环境的影响,表现出不同的功能。这提示着TGF-β信号通路和其他信号通路之间存在非常强的交互作用。本文的重点在于对TGF-β在前列腺癌骨转移中的作用研究进展进行综述,阐述TGF-β对转移灶中不同细胞的作用,为今后肿瘤的治疗研究寻找一个好的方向。     

MicroRNA-153 Inhibits Osteosarcoma Cells Proliferation and Invasion by Targeting TGF-β2

Increasing evidence indicates that microRNAs (miRNAs), a class of small noncoding RNAs, participate in almost every step of cellular processes. MiRNAs are aberrantly expressed in human cancers and contribute to cancer development and progression. Study of miRNAs may provide a new clue for understanding the mechanism of carcinogenesis and a new tool for cancer treatment. In the present study, miR-153 was downregulated in human osteosarcoma tissues and cell lines. Introduction of miR-153 mimics into the MG-63 cells inhibited cell proliferation and invasion. Our results further revealed that transforming growth factor beta 2 (TGF-β2) was negatively regulated by miR-153. Furthermore, overexpression of miR-153 decreased p-SMAD2, p-SMAD3, epidermal growth factor receptor (EGFR) and insulin-like growth factor binding protein-3 (IGFBP-3) expressions, which were the downstream signaling molecules of TGF-β. Furthermore, miRNA-153 suppressed TGF-β-mediated MG-63 proliferation and migration. Therefore, our results suggest that miR-153 may act as a tumor suppressor in osteosarcoma through targeting TGF-β2.     

Smad2 与TGF-β1 基因在胰腺癌中的表达及临床意义

目的:通过检测Smad2与TGF-β1基因在胰腺癌中的表达,初步探讨它们与胰腺癌临床病理的关系。方法:采用免疫组织化学pv-9000法检测50例胰腺癌组织和10例正常胰腺组织中Smad2与TGF-β1的表达情况,并分析其与胰腺癌临床病理的相关性。结果:Smad2与TGF-β1在胰腺癌组织中的表达水平显著高于正常胰腺组织,两组之间存在显著差异(P<0.05)。在胰腺癌组织中,Smad2与TGF-β1的表达在胰腺癌不同分期中存在显著差异(P<0.05)。结论:Smad2与TGF-β1在胰腺癌中高表达,二者联合可作为反映胰腺癌临床分期的生物学指标。