Kruppel-Like Factor 2 Is Required for Normal Mouse Cardiac Development
Kruppel-Like Factor 2 Is Required for Normal Mouse Cardiac Development
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DOI：
10.1371/journal.pone.0054891
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发表时间：
2013-02-14
期刊：
影响因子：
3.7
通讯作者：
Lloyd, Joyce A.
中科院分区：
文献类型：
--
作者：
Chiplunkar, Aditi R.;Lung, Tina K.;Lloyd, Joyce A.
Kruppel-like factor2(KLF2)在发育中的心脏内皮细胞中表达，特别是在高切应力区域，如房室管。在混合遗传背景下，KLF2消融导致心肌变薄、高输出量心力衰竭和小鼠胚胎14.5天(E14.5)死亡。这项工作确定了KLF2在FVB/N小鼠心脏发育中更早和更基本的作用。FVB/N KLF2-/-胚胎死亡更早，到E11.5。E9.5 FVB/N KLF2-/-心脏有多层杂乱的细胞层排列在房室垫上，房室瓣的原基，而不是正常的单层。到E10.5，传统的和内皮特异性的FVB/N KLF2-/-房室垫细胞减少，这表明聚集在房室管的细胞在内皮向间充质转化(EMT)方面存在缺陷。E10.5 FVB/N KLF2-/-心脏凝胶中的糖胺聚糖减少，与EMT减少相关。然而，与野生型相比，从FVB/N KLF2-/-AV移植到胶原基质中的间充质细胞数量显著减少，这表明EMT缺陷不仅仅是由于心脏凝胶的异常。E10.5FVB/N KLF2-/-胚胎的超声心动图显示，与野生型相比，它们的心功能异常。E10.5 C57BL/6 KLF2-/-心脏的房室垫基本正常。然而，E10.5FVB/N和C57BL/6KLF2-/-胚胎在房间隔的形成方面有延迟，这在特定的混合背景下是没有观察到的。KLF2消融可导致FVB/N房室管SOX9、UDP-葡萄糖脱氢酶(UGDH)、GATA4和Tbx5mRNA表达降低。在染色质免疫沉淀实验中，KLF2与Gata4、Tbx5和UGDH启动子结合，表明KLF2可以直接调控这些基因。总之，KLF2-/-心脏表型与遗传背景有关。KLF2通过调节重要的心血管基因在EMT中发挥作用。
Kruppel-like factor 2 (KLF2) is expressed in endothelial cells in the developing heart, particularly in areas of high shear stress, such as the atrioventricular (AV) canal. KLF2 ablation leads to myocardial thinning, high output cardiac failure and death by mouse embryonic day 14.5 (E14.5) in a mixed genetic background. This work identifies an earlier and more fundamental role for KLF2 in mouse cardiac development in FVB/N mice. FVB/N KLF2-/- embryos die earlier, by E11.5. E9.5 FVB/N KLF2-/- hearts have multiple, disorganized cell layers lining the AV cushions, the primordia of the AV valves, rather than the normal single layer. By E10.5, traditional and endothelial-specific FVB/N KLF2-/- AV cushions are hypocellular, suggesting that the cells accumulating at the AV canal have a defect in endothelial to mesenchymal transformation (EMT). E10.5 FVB/N KLF2-/- hearts have reduced glycosaminoglycans in the cardiac jelly, correlating with the reduced EMT. However, the number of mesenchymal cells migrating from FVB/N KLF2-/- AV explants into a collagen matrix is reduced considerably compared to wild-type, suggesting that the EMT defect is not due solely to abnormal cardiac jelly. Echocardiography of E10.5 FVB/N KLF2-/- embryos indicates that they have abnormal heart function compared to wild-type. E10.5 C57BL/6 KLF2-/- hearts have largely normal AV cushions. However, E10.5 FVB/N and C57BL/6 KLF2-/- embryos have a delay in the formation of the atrial septum that is not observed in a defined mixed background. KLF2 ablation results in reduced Sox9, UDP-glucose dehydrogenase (Ugdh), Gata4 and Tbx5 mRNA in FVB/N AV canals. KLF2 binds to the Gata4, Tbx5 and Ugdh promoters in chromatin immunoprecipitation assays, indicating that KLF2 could directly regulate these genes. In conclusion, KLF2-/- heart phenotypes are genetic background-dependent. KLF2 plays a role in EMT through its regulation of important cardiovascular genes.