Institute for Molecular and Cellular Regulation, Gunma University, Maebashi, Japan.
J Cell Biochem. 2011 Jan;112(1):318-29. doi: 10.1002/jcb.22930.
Extracellular matrix (ECM) modulates differentiation of pancreatic β-cells during development. However, the mechanism by which ECM proteins modulate differentiation is not totally clear. We investigated the effect of ECM proteins on differentiation β-cells in vitro. We investigated the effect of basement membrane ECM on differentiation of AR42J cells and rat ductal cells. First, we examined the effect of reconstituted basement membrane, Matrigel on differentiation of AR42J cells induced by activin and betacellulin. Matrigel augmented insulin production and increased the expression of GLUT2, SUR1, and glucokinase. Among various transcription factors investigated, Matrigel markedly upregulated the expression of Pax6. When Pax6 was overexpressed in cells treated with activin and betacellulin, the expression of insulin was upregulated. Conversely, knockdown of Pax6 significantly reduced the insulin expression in cells cultured on Matrigel. The effects of Matrigel on insulin-production and induction of Pax6 were reproduced partially by laminin-1, a major component of Matrigel, and inhibited by anti-integrin-β1 antibody. Matrigel also enhanced the activation of p38 mitogen-activated kinase induced by activin and betacellulin, which was inhibited by anti-β1 antibody. Finally, the effect of Matrigel on differentiation was reproduced in rat cultured ductal cells, and Matrigel also increased the expression of Pax6. These results indicate that basement membrane ECM augments differentiation of pancreatic progenitor cells to insulin-secreting cells by upregulating the expression of Pax6. .
细胞外基质（ECM）在胰腺β细胞的发育过程中调节其分化。然而，ECM 蛋白调节分化的机制尚不完全清楚。我们研究了 ECM 蛋白对体外β细胞分化的影响。我们研究了基底膜 ECM 对 AR42J 细胞和大鼠导管细胞分化的影响。首先，我们检测了再构成基底膜 Matrigel 对激活素和β细胞素诱导的 AR42J 细胞分化的影响。Matrigel 增强了胰岛素的产生，并增加了 GLUT2、SUR1 和葡萄糖激酶的表达。在研究的各种转录因子中，Matrigel 明显地上调了 Pax6 的表达。当在接受激活素和β细胞素处理的细胞中过表达 Pax6 时，胰岛素的表达上调。相反，在 Matrigel 上培养的细胞中敲低 Pax6 显著降低了胰岛素的表达。Matrigel 对胰岛素产生和 Pax6 诱导的影响部分可被 Matrigel 的主要成分层粘连蛋白-1 重现，并可被抗整合素-β1 抗体抑制。Matrigel 还增强了激活素和β细胞素诱导的 p38 丝裂原活化激酶的激活，该激活可被抗β1 抗体抑制。最后，Matrigel 在大鼠培养的导管细胞中的分化作用得以重现，Matrigel 还增加了 Pax6 的表达。这些结果表明，基底膜 ECM 通过上调 Pax6 的表达增强了胰腺祖细胞向胰岛素分泌细胞的分化。
