Dnmt3a-mediated inhibition of Wnt in cardiac progenitor cells improves differentiation and remote remodeling after infarction
Dnmt3a-mediated inhibition of Wnt in cardiac progenitor cells improves differentiation and remote remodeling after infarction
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DOI：
10.1172/jci.insight.91810
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发表时间：
2017-06-15
期刊：
影响因子：
8
通讯作者：
Balligand, Jean-Luc
中科院分区：
文献类型：
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作者：
De Pauw, Aurelia;Andre, Emilie;Balligand, Jean-Luc
成体心脏祖细胞（CPCs）在损伤心脏中分化为心肌细胞的能力较低，严重限制了哺乳动物心肌的再生能力。为了确定调节CPC分化的新机制，我们使用小鼠成年心脏的原代和克隆扩增的Sca-1(+) CPC进行同型培养或与心肌细胞共培养。同型培养分化过程中的表达动力学分析显示，Wnt靶基因下调，同时Wnt拮抗剂Wnt抑制因子1 （Wnt inhibitory factor 1, Wif1）的表达增加，这是刺激CPC分化所必需的。我们发现，Wif1基因的表达受到DNA甲基化的抑制，并受到新生DNA甲基转移酶Dnmt3a的调节。此外，miR-29a在CPC分化早期上调，下调Dnmt3a表达，从而降低Wif1基因甲基化，提高体外Sca-1(+) CPC的分化效率。将这些发现扩展到体内，随后在梗死小鼠心脏边界区注射的CPCs中短暂沉默Dnmt3a可改善原位CPC分化和远程心脏重构。综上所述，miR-29a和Dnmt3a通过抑制Wnt从表观遗传学角度调控CPC分化。对心脏重塑的远程影响支持局部注射部位以外的旁分泌信号，对心脏修复具有潜在的治疗意义。
Adult cardiac progenitor cells (CPCs) display a low capacity to differentiate into cardiomyocytes in injured hearts, strongly limiting the regenerative capacity of the mammalian myocardium. To identify new mechanisms regulating CPC differentiation, we used primary and clonally expanded Sca-1(+) CPCs from murine adult hearts in homotypic culture or coculture with cardiomyocytes. Expression kinetics analysis during homotypic culture differentiation showed downregulation of Wnt target genes concomitant with increased expression of the Wnt antagonist, Wnt inhibitory factor 1 (Wif1), which is necessary to stimulate CPC differentiation. We show that the expression of the Wif1 gene is repressed by DNA methylation and regulated by the de novo DNA methyltransferase Dnmt3a. In addition, miR-29a is upregulated early during CPC differentiation and downregulates Dnmt3a expression, thereby decreasing Wif1 gene methylation and increasing the efficiency of differentiation of Sca-1(+) CPCs in vitro. Extending these findings in vivo, transient silencing of Dnmt3a in CPCs subsequently injected in the border zone of infarcted mouse hearts improved CPC differentiation in situ and remote cardiac remodeling. In conclusion, miR-29a and Dnmt3a epigenetically regulate CPC differentiation through Wnt inhibition. Remote effects on cardiac remodeling support paracrine signaling beyond the local injection site, with potential therapeutic interest for cardiac repair.