Stem Cell and Biotheraphy Technology Research Center, Xinxiang Medical University, Xinxiang, China.
Henan Key Laboratory of Medical Tissue Regeneration, Xinxiang Medical University, Xinxiang, China.
Cardiovasc Ther. 2017 Dec;35(6). doi: 10.1111/1755-5922.12305. Epub 2017 Sep 27.
BACKGROUND/AIMS: The differentiation efficiency of bone marrow mesenchymal stem cells (BM-MSCs) is low in vivo after transplantation. Therefore, it is necessary to look for effective reagents for enhancing cardiac differentiation of BM-MSCs. It has been reported that cardiac differentiation of stem cells depends on the activation of extracellular signal-regulated protein 1/2 (ERK1/2) signaling. Oxidized low-density lipoprotein (ox-LDL) is a potent reagent for ERK1/2 activation. This indicates that ox-LDL may be a potential reagent to stimulate cardiac differentiation of stem cells. In this study, we investigated the effect of ox-LDL on cardiac differentiation of BM-MSCs and its relationship with ERK1/2 signaling.
BM-MSCs were isolated from mouse bone marrow, cultured in DMEM supplemented with 15% FBS, and passaged up to the 3rd passage. Following culture with 5 μg/mL ox-LDL for 3 weeks, the cardiac differentiation of the 3rd passage BM-MSCs was identified by immunostaining, Western blotting, and RT-PCR assays for measuring the expression of cardiac-specific markers. To further explore the role of ERK1/2 signaling in cardiac differentiation of BM-MSCs, we simultaneously exposed BM-MSCs to ERK1/2 inhibitor (U0126) and ox-LDL, and identified the cardiac differentiation again.
The expressions of cardiac-specific markers including α-cardiac actin, α-MHC, β-MHC, ANP, and BNP were markedly increased in BM-MSCs following treatment with ox-LDL (P < .05), which indicates a directional differentiation of BM-MSCs to cardiac cells. Further, ox-LDL could also activate ERK1/2 in BM-MSCs, and application of U0126 markedly inhibited ox-LDL-induced cardiac transformation of BM-MSCs.
Ox-LDL induces cardiac differentiation of BM-MSCs via activation of ERK1/2 signaling.
背景/目的：骨髓间充质干细胞（BM-MSCs）在体内移植后的分化效率较低。因此，有必要寻找有效的试剂来增强 BM-MSCs 的心脏分化。据报道，干细胞的心脏分化依赖于细胞外信号调节蛋白 1/2（ERK1/2）信号的激活。氧化型低密度脂蛋白（ox-LDL）是激活 ERK1/2 的有效试剂。这表明 ox-LDL 可能是刺激干细胞心脏分化的潜在试剂。在这项研究中，我们研究了 ox-LDL 对 BM-MSCs 心脏分化的影响及其与 ERK1/2 信号的关系。
从小鼠骨髓中分离 BM-MSCs，在含有 15% FBS 的 DMEM 中培养，并传代至第 3 代。第 3 代 BM-MSCs 用 5μg/mL ox-LDL 培养 3 周后，通过免疫染色、Western blot 和 RT-PCR 检测测量心脏特异性标志物的表达来鉴定其心脏分化。为了进一步探讨 ERK1/2 信号在 BM-MSCs 心脏分化中的作用，我们同时将 BM-MSCs 暴露于 ERK1/2 抑制剂（U0126）和 ox-LDL 中，并再次鉴定其心脏分化。
ox-LDL 处理后，BM-MSCs 中心脏特异性标志物如α-心脏肌动蛋白、α-MHC、β-MHC、ANP 和 BNP 的表达明显增加（P<.05），这表明 BM-MSCs 向心脏细胞的定向分化。此外，ox-LDL 还可以激活 BM-MSCs 中的 ERK1/2，而 U0126 的应用则显著抑制了 ox-LDL 诱导的 BM-MSCs 心脏转化。
ox-LDL 通过激活 ERK1/2 信号诱导 BM-MSCs 的心脏分化。
