结缔组织生长因子对血管生成和细胞功能的调节

结缔组织生长因子(CTGF)是CCN家族的主要成员,是研究较多的CCN蛋白之一。CTGF能促进细胞的增殖、存活、迁移和黏附,调节血管生成分子(bFGF,VEGF)以及一些影响胞外基质完整性和稳定性的分子(胶原、MMPs和TIMPs)的活性。CTGF可以在多个控制位点采取直接或间接的机制调控细胞功能和血管生成。结合新的发现和新的视点,阐述CTGF对细胞功能和血管生成的调控作用以及与肿瘤生长的关系。     

结缔组织生长因子与肾脏纤维化

结缔组织生长因子属于CNN家族,是TGF-β的下游因子,它的表达受到TGF-β强烈诱导。结缔组织生长因子介导了FN、ColⅠ、ColⅢ、ColⅣ等mRNA及蛋白的表达,在纤维化的过程中可能起着重要的作用。     

人结缔组织生长因子(CTGF)的原核表达研究

随着对细胞前早期基因认识的深入,一组在多个种群中具有较高同源性的前早期基因家族——CCN(CTGF,Cyr61/Cef10,Nxov)得到了人们的注意[1]。其产物在细胞受到创伤刺激时产生,并具有促进和调节创伤修复的功能.其中的人结缔组织生长因子(CTGF)由于对成纤维细胞、结缔组织基质...     

A Neoplastic Connective Tissue Mast Cell Capable of Continuous Growth In Tissue Culture

A neoplastic connective tissue mast cell from a dog mast cell sarcoma has been grown in tissue culture for 50 passages over a period of 2 years. The cells were grown as monolayer cultures in glass bottles, using Eagle's basal medium fortified with calf serum. The cultures were contaminated with an Alkaligenes sp. for 10 months but finally were sterilized bacteriologically by treatment with specific antiserum combined with antibiotics. The cells grow in a fibroblastic pattern, and contain mitochondria, mast cell granules, and lipid granules or droplets. The mast cell granules stain basophilic with Giemsa's stain and metachromatically with azure A or toluidine blue. They also stain with Sudan black B and with periodic acid-Schiff stain. The interphase nuclei are vesicular, contain from 1 to 20 nucleoli, and frequently show bizarre outlines. Multinucleate cells are often seen, as are mitotic figures. Extracellular fibrous material occurs in all cultures and apparently originates from the cell surface. This material does not have the structure of connective tissue fibers and has not been identified. The cells develop an increased number of metachromatic granules when grown in medium containing heparin and an increased number of sudanophilic granules when grown in medium containing stearic acid. Only small amounts of histamine were present in the tumor from which this cell line was derived and in the cells grown in tissue culture.     

Connective Tissue Growth Factor in Regulation of RhoA Mediated Cytoskeletal Tension Associated Osteogenesis of Mouse Adipose-Derived Stromal Cells

Background

Cytoskeletal tension is an intracellular mechanism through which cells convert a mechanical signal into a biochemical response, including production of cytokines and activation of various signaling pathways.

Methods/Principal Findings

Adipose-derived stromal cells (ASCs) were allowed to spread into large cells by seeding them at a low-density (1,250 cells/cm²), which was observed to induce osteogenesis. Conversely, ASCs seeded at a high-density (25,000 cells/cm²) featured small cells that promoted adipogenesis. RhoA and actin filaments were altered by changes in cell size. Blocking actin polymerization by Cytochalasin D influenced cytoskeletal tension and differentiation of ASCs. To understand the potential regulatory mechanisms leading to actin cytoskeletal tension, cDNA microarray was performed on large and small ASCs. Connective tissue growth factor (CTGF) was identified as a major regulator of osteogenesis associated with RhoA mediated cytoskeletal tension. Subsequently, knock-down of CTGF by siRNA in ASCs inhibited this osteogenesis.

Conclusions/Significance

We conclude that CTGF is important in the regulation of cytoskeletal tension mediated ASC osteogenic differentiation.     

促肝纤维化的关键因子——结缔组织生长因子

结缔组织生长因子（CTGF）与转化生长因子β（TGF-β）高表达于多种纤维化的组织器官中,被认为是促纤维化发生的主要细胞因子。作为TGF-β生物学作用的下游效应介质,CTGF介导TGF-β促组织纤维化的效应,而与TGF—β抗炎、调节免疫等其他生物学效应无明显相关,因此可能成为抗肝纤维化的更好的靶点。     

结缔组织生长因子在心衰后心室重构的研究进展

心力衰竭是各种心血管疾病发展的终末阶段,而心室重构贯穿于心衰发生、发展的全过程,阻断心室重构是防治心衰不容忽视的一个重要环节。结缔组织生长因子是一种新发现的具有多种生物学功能的成纤维细胞生长因子,在病理情况下,能抑制心肌细胞外基质的降解,促进心肌细胞的凋亡,与动脉粥样硬化、器官纤维化、创伤后修复及组织瘢痕形成等密切相关。作为参与心力衰竭后心室重构的细胞因子,不仅能够成为评价心衰患者临床预后的指标,还有望成为抗纤维化治疗的新靶点。     

Mixed Connective Tissue Disease

A study was done that involved 46 patients with high-titer serum antibody to ribonucleoprotein (RNP). Common cutaneous manifestations included swollen hands or sclerodactyly (50 percent), cutaneous lupus erythematosus (48 percent), periungual telangiectasia (46 percent), alopecia (46 percent), dyspigmentation (28 percent), photosensitivity (28 percent) and vasculitis (22 percent). Frequent systemic characteristics included Raynaud phenomenon (93 percent), arthritis or arthralgia (91 percent), adenopathy (43 percent), vascular headaches (35 percent), serositis (35 percent), hoarseness (28 percent), myositis (26 percent), sicca syndrome (24 percent), renal disease (17 percent) and central nervous system disease (9 percent). Associated laboratory findings included antinuclear antibodies (100 percent), epidermal nuclear lgG deposition (91 percent), hypergammaglobulinemia (78 percent), esophageal dysmotility (61 percent), abnormal pulmonary function (59 percent), rheumatoid factor (57 percent), lupus erythematosus cells (37 percent), positive lupus band test (34 percent), hypocomplementemia (28 percent) and elevated anti-nDNA (21 percent).It appears that patients with high-titer anti-RNP (without appreciable amounts of “anti-Sm”) have a high prevalence of Raynaud phenomenon and a low prevalence of progressive renal insufficiency and severe central nervous system disease.     

Use of Human Fibroblasts Grown on Microcarriers for Formation of Connective Tissue Equivalent

Living equivalents of tissues, specifically those produced on the basis of fibroblasts and collagen gel, are widely used for repair of organ and tissues defects. In clinical practice, it is more convenient to use the fibroblasts grown on microcarriers or such a connective tissue equivalent when the fibroblasts on microcarriers are embedded in collagen gel. We studied the properties of a connective tissue equivalent produced by embedding the fibroblasts grown on microcarriers in collagen gel for its prospective use in clinical practice. According to our results, the optimal time of use of the living tissue equivalent amounts to three–four days after embedding of fibroblasts on microcarriers in gel. At that time, contraction only begins, which facilitates manipulations with the gel.     

Periodic-Acid-Foot Stain for Connective Tissue

A marked increase in reticular argyrophilia may be obtained in the Foot ammoniated silver carbonate technic by interposing a strong periodic acid oxidation, 4% aqueous for 2 hours at 25-27°C., prior to silvering. Sections so oxidized before the silver bath show a histological picture of connective tissue that is stronger than that given by the original technic. Stroma of lymphoid tissues (but not other types) is further intensified by brief (5-10 sec.) passage through aqueous 1.5% uranium nitrate after oxidation but before silver impregnation. The specific action of periodic acid (cleavage of the 1,2-glycol linkage to produce aldehyde radicals) strengthens the premise that the carbonyl radical plays an important part in the phenomenon of connective tissue argyrophilia.     

Connective Tissue Growth Factor (CTGF) Expression Modulates Response to High Glucose

Connective tissue growth factor (CTGF) is an important mediator of fibrosis; emerging evidence link changes in plasma and urinary CTGF levels to diabetic kidney disease. To further ascertain the role of CTGF in responses to high glucose, we assessed the consequence of 4 months of streptozotocin-induced diabetes in wild type (+/+) and CTGF heterozygous (+/−) mice. Subsequently, we studied the influence of glucose on gene expression and protein in mice embryonic fibroblasts (MEF) cells derived from wildtype and heterozygous mice. At study initiation, plasma glucose, creatinine, triglyceride and cholesterol levels were similar between non-diabetic CTGF+/+ and CTGF+/− mice. In the diabetic state, plasma glucose levels were increased in CTGF+/+ and CTGF+/− mice (28.2 3.3 mmol/L vs 27.0 3.1 mmol/L), plasma triglyceride levels were lower in CTGF+/− mice than in CTGF+/+ (0.7 0.2 mmol/L vs 0.5 0.1 mmol/L, p<0.05), but cholesterol was essentially unchanged in both groups. Plasma creatinine was higher in diabetic CTGF+/+ group (11.7±1.2 vs 7.9±0.6 µmol/L p<0.01), while urinary albumin excretion and mesangial expansion were reduced in diabetic CTGF+/− animals. Cortices from diabetic mice (both CTGF +/+ and CTGF +/−) manifested higher expression of CTGF and thrombospondin 1 (TSP1). Expression of nephrin was reduced in CTGF +/+ animals; this reduction was attenuated in CTGF+/− group. In cultured MEF from CTGF+/+ mice, glucose (25 mM) increased expression of pro-collagens 1, IV and XVIII as well as fibronectin and thrombospondin 1 (TSP1). In contrast, activation of these genes by high glucose was attenuated in CTGF+/− MEF. We conclude that induction of Ctgf mediates expression of extracellular matrix proteins in diabetic kidney. Thus, genetic variability in CTGF expression directly modulates the severity of diabetic nephropathy.     

Natural Haemozoin Induces Expression and Release of Human Monocyte Tissue Inhibitor of Metalloproteinase-1

Recently matrix metalloproteinase-9 (MMP-9) and its endogenous inhibitor (tissue inhibitor of metalloproteinase-1, TIMP-1) have been implicated in complicated malaria. In vivo, mice with cerebral malaria (CM) display high levels of both MMP-9 and TIMP-1, and in human patients TIMP-1 serum levels directly correlate with disease severity. In vitro, natural haemozoin (nHZ, malarial pigment) enhances monocyte MMP-9 expression and release. The present study analyses the effects of nHZ on TIMP-1 regulation in human adherent monocytes. nHZ induced TIMP-1 mRNA expression and protein release, and promoted TNF-α, IL-1β, and MIP-1α/CCL3 production. Blocking antibodies or recombinant cytokines abrogated or mimicked nHZ effects on TIMP-1, respectively. p38 MAPK and NF-κB inhibitors blocked all nHZ effects on TIMP-1 and pro-inflammatory molecules. Still, total gelatinolytic activity was enhanced by nHZ despite TIMP-1 induction. Collectively, these data indicate that nHZ induces inflammation-mediated expression and release of human monocyte TIMP-1 through p38 MAPK- and NF-κB-dependent mechanisms. However, TIMP-1 induction is not sufficient to counterbalance nHZ-dependent MMP-9 enhancement. Future investigation on proteinase-independent functions of TIMP-1 (i.e. cell survival promotion and growth/differentiation inhibition) is needed to clarify the role of TIMP-1 in malaria pathogenesis.     

结缔组织生长因子小干扰RNA的构建及其干扰效果检测

目的：构建结缔组织生长因子（CTGF）基因的小干扰RNA（siRNA）,并检测其对CTGF基因表达的干扰效果。方法：根据CTGF基因序列,设计2条合理的CTGF-siRNA,并将其克隆到siRNA载体pSliencer2．1-U6neo中,转化大肠杆菌DH5a,挑取阳性菌落进行酶切和测序鉴定;将构建成功的CTGF-siRNA重组质粒与带nJAG标签的CTGF表达载体共同转染人胚肾293T细胞,Western印迹检测siRNA的干扰效果。结果：构建了2个CTGFpsiRNA重组质粒,2条siRNA都有干扰作用,其中一条的干扰效果可达75％以上。结论：构建的CTGF-siRNA可为进一步研究CTGF的功能提供参考。