Department of Veterinary Physiology, Biotherapy Human Resources Center (BK 21), College of Veterinary Medicine, Chonnam National University, Gwangju 500-757, Korea.
J Cell Physiol. 2010 May;223(2):397-407. doi: 10.1002/jcp.22048.
The role of individual supplements necessary for the long-term self-renewal of embryonic stem (ES) cells is poorly characterized in feeder/serum-free culture systems. This study sought to characterize the relationship between the effects of glucose on ES cell proliferation and fibronectin (FN) synthesis, and to assess the mechanisms responsible for these cellular effects of glucose. Treatment of the two ES cells (ES-E14TG2a and ES-R1) with 25 mM glucose (high glucose) increased the expression levels of FN mRNA and protein. In addition, high glucose and ANG II synergistically increased FN expression level, which coincident with data showing that high glucose increased the mRNA expression of angiotensin II (ANG II) type 1 receptor (AT(1)R), angiotensinogen, and FN, but not ANG II type 2 receptor. High glucose also increased the intracellular calcium (Ca(2+)) concentration and pan-protein kinase C (PKC) phosphorylation. Inhibition of the Ca(2+)/PKC pathway blocked high glucose-induced FN expression. High glucose or ANG II also synergistically increased transforming growth factor-beta1 (TGF-beta(1)) expression, while pretreatment with losartan abolished the high glucose-induced increase in TGF-beta(1) production. Moreover, TGF-beta(1)-specific small interfering RNA inhibited high glucose-induced FN expression and c-Jun N-terminal kinase (JNK) activation. The JNK inhibitor SP600125 blocked high glucose-induced FN expression and inhibited cell cycle regulatory protein expression induced by high glucose or TGF-beta(1). In this study, inhibition of AT(1)R, Ca(2+)/PKC, TGF-beta(1), JNK, FN receptor blocked the high glucose-induced DNA synthesis, increased the cell population in S phase, and the number of cells. It is concluded that high glucose increases FN synthesis through the ANG II or TGF-beta1 pathways, which in part mediates proliferation of mouse ES cells.
胚胎干细胞（ES）长期自我更新所需的个体补充剂的作用在无饲养层/无血清培养系统中特征描述较差。本研究旨在表征葡萄糖对 ES 细胞增殖和纤连蛋白（FN）合成的影响之间的关系，并评估葡萄糖对这些细胞作用的机制。用 25mM 葡萄糖（高葡萄糖）处理两种 ES 细胞（ES-E14TG2a 和 ES-R1）增加了 FN mRNA 和蛋白的表达水平。此外，高葡萄糖和 ANG II 协同增加 FN 的表达水平，这与以下数据一致，即高葡萄糖增加血管紧张素 II（ANG II）1 型受体（AT(1)R）、血管紧张素原和 FN 的 mRNA 表达，但不增加 ANG II 2 型受体。高葡萄糖还增加了细胞内钙（Ca(2+))浓度和全蛋白激酶 C（PKC）磷酸化。抑制 Ca(2+)/PKC 途径阻断了高葡萄糖诱导的 FN 表达。高葡萄糖或 ANG II 也协同增加转化生长因子-β1（TGF-β(1))的表达，而用洛沙坦预处理则消除了高葡萄糖诱导的 TGF-β(1)产生增加。此外，TGF-β(1)特异性小干扰 RNA 抑制了高葡萄糖诱导的 FN 表达和 c-Jun N-末端激酶（JNK）激活。JNK 抑制剂 SP600125 阻断了高葡萄糖诱导的 FN 表达，并抑制了高葡萄糖或 TGF-β(1)诱导的细胞周期调节蛋白表达。在这项研究中，抑制 AT(1)R、Ca(2+)/PKC、TGF-β(1)、JNK、FN 受体阻断了高葡萄糖诱导的 DNA 合成，增加了 S 期细胞群体和细胞数量。结论是，高葡萄糖通过 ANG II 或 TGF-β1 途径增加 FN 合成，部分介导了小鼠 ES 细胞的增殖。
