细胞外基质组成影响大鼠IEC-18细胞中胰岛素样生长因子I受体的表达。

Extracellular matrix composition influences insulinlike growth factor I receptor expression in rat IEC-18 cells.

作者信息

Benya R V, Duncan M D, Mishra L, Bass B L, Voyles N R, Korman L Y

机构信息

Research Service, Veterans Administration Medical Center, Washington, D.C.

出版信息

Gastroenterology. 1993 Jun;104(6):1705-11. doi: 10.1016/0016-5085(93)90649-w.

DOI:10.1016/0016-5085(93)90649-w

PMID:8500730

Abstract

BACKGROUND

The composition of the extracellular matrix (ECM) as well as insulinlike growth factor I (IGF-I) receptor density vary along the crypt-villus axis. We determined whether components of the ECM influence IGF-I receptor expression in IEC-18 rat small intestine crypt cells.

METHODS

IEC-18 cells were cultured on plastic, collagen type IV, Matrigel, and laminin at the plateau and proliferative growth phases. Receptor affinity (Kd) and number (Bmax) were determined by competitive binding of 125I-IGF-I in the presence of increasing concentrations of unlabeled IGF-I. Receptor isolation was performed by affinity cross linking. Messenger RNA (mRNA) for IGF-I receptor was quantified by Northern analysis.

RESULTS

Specific binding of IGF-I > IGF-II > insulin was observed. A 130,000-molecular weight protein was identified by cross-linking, consistent with the alpha subunit of the IGF-I receptor. Scatchard analysis revealed no effect of ECM on IGF-I binding affinity. In contrast, the Bmax was 18% lower for plateau-phase cells cultured on Matrigel vs. plastic and was 42% lower for cells cultured on laminin vs. collagen type IV. The Bmax for proliferative growth phase cells was decreased when cultured on Matrigel vs. plastic and was 10-fold less than for cells cultured at the plateau growth phase. Northern analysis revealed that IEC-18 cells cultured on Matrigel had less mRNA for IGF-I receptor than cells cultured on plastic.

CONCLUSIONS

The rate of cell proliferation and the composition of the ECM influence IGF-I receptor expression in IEC-18 cells.

摘要

背景

细胞外基质（ECM）的组成以及胰岛素样生长因子I（IGF-I）受体密度沿隐窝-绒毛轴变化。我们确定了ECM的成分是否影响IEC-18大鼠小肠隐窝细胞中IGF-I受体的表达。

方法

在平台期和增殖期，将IEC-18细胞培养在塑料、IV型胶原、基质胶和层粘连蛋白上。通过在增加浓度的未标记IGF-I存在下125I-IGF-I的竞争性结合来确定受体亲和力（Kd）和数量（Bmax）。通过亲和交联进行受体分离。通过Northern分析对IGF-I受体的信使核糖核酸（mRNA）进行定量。

结果

观察到IGF-I>IGF-II>胰岛素的特异性结合。通过交联鉴定出一种分子量为130,000的蛋白质，与IGF-I受体的α亚基一致。Scatchard分析显示ECM对IGF-I结合亲和力没有影响。相比之下，在基质胶上培养的平台期细胞的Bmax比在塑料上培养的低18%，在层粘连蛋白上培养的细胞比在IV型胶原上培养的低42%。在基质胶上培养时，增殖期细胞的Bmax比在塑料上培养时降低，且比在平台期培养的细胞低10倍。Northern分析显示，在基质胶上培养的IEC-18细胞的IGF-I受体mRNA比在塑料上培养的细胞少。