GROWTH FACTOR/CYTOKINE INTERACTIONS IN MESENCHYMAL CELLS

慢性肠炎可引起伤口愈合反应 以间充质细胞增殖和增加为特征 细胞外基质(ECM)沉积。这种纤维化反应会导致 狭窄和梗阻的并发症。有一种提升的表达 胰岛素样生长因子(IGF-I和IGF-II)在糖尿病动物模型中的表达 慢性肠炎与非霍奇金淋巴瘤患者的受累肠管 克罗恩病(CD)。胰岛素样生长因子促进间充质细胞生长和 增强其他荷尔蒙的增殖作用。我们假设 IGFS与细胞因子和细胞外基质共同促进纤维化相关 用Cd刺激肠成纤维细胞改变表型，增加 细胞增殖和胶原沉积。为了检验这一假设，我们 建议使用从人类肠道分离的成纤维细胞系 结肠成纤维细胞(CCD-18Co)和正常培养的人肠成纤维细胞 模型系统。首先，我们将评估IGF-I单独和在 与CD相关的其他生长因子和细胞因子的结合 DNA合成和细胞数量、表型，由α-Smooth判断 肌肉肌动蛋白和胶原沉积，由胶原蛋白和胶原酶判断 基因表达和胶原蛋白的产生。接下来，我们将考察 胰岛素样生长因子-I、碱性成纤维细胞生长因子协同作用的细胞内机制 IL-1对细胞增殖的影响。这将包括对类型的检查 IGF受体和IGFBPs可能调节IGF的反应性。在……里面 此外，将使用一种转染法来评估 AP-1信号在介导IGF、bFGF、IL-1作用中的作用 互动。最后，我们将比较从 从狭窄处提取的ECM对健康肠段的影响 Gd对DNA合成、细胞数量、分化、IGF表达的影响 对IGF的反应。

Chronic inflammation of the bowel induces a wound-healing response characterized by proliferation of mesenchymal cells and increased extracellular matrix (ECM) deposition. This fibrogenic response causes complications of stricture and obstruction. There is elevated expression of insulin-like growth factors (IGF-I and IGF-II) in animal models of chronic bowel inflammation and in the involved bowel of patients with Crohn's disease (CD). IGFs stimulate mesenchymal cell growth and potentiate proliferative actions of other hormones. We hypothesize that IGFs work together with cytokines and ECM to promote fibrosis associated with CD by stimulating enteric fibroblasts to change phenotype, increase proliferation and collagen deposition. To test this hypothesis, we propose to use an enteric fibroblast cell line isolated from the human colon (CCD-18Co) and normal, cultured human intestinal fibroblasts as model systems. First, we will assess the effects of IGF-I alone and in combination with other growth factors and cytokines implicated in CD on DNA synthesis and cell number, phenotype, as judged by alpha-smooth muscle actin, and collagen deposition, judged by collagen and collagenase gene expression and collagen production. Next, we will examine intracellular mechanisms underlying synergistic effects of IGF-I, bFGF and IL-1 on cell proliferation. This will include an examination of type I IGF receptor and IGFBPs that may modulate IGF responsiveness. In addition, a transfection approach will be used to assess the role of the AP-1 signaling in mediating IGF, bFGF, IL-1 action and their interactions. Finally, we will compare the effects of ECM extracted from healthy segment of bowel with the effects of ECM extracted from stricture of GD on DNA synthesis, cell number, differentiation, IGF expression and responsiveness to IGF.