Introduction

Induced pluripotent stem cell (iPSC)-derived endothelial cells (ECs) have the potential for therapeutic application in several cardiovascular diseases. Mechanical strain is known to regulate EC behavior and stem cell differentiation and may play a role in directing EC differentiation of iPSCs. H19, a long non-coding RNA (lncRNA), is known to affect ECs in several mechanically relevant pathologies and may play a role in this process as well. Therefore, we investigated expression changes of H19 resulting from mechanical stimulation during EC differentiation, as well as functional effects on EC tube formation.

Methods

iPSCs were subjected to 5% cyclic mechanical strain during EC differentiation. RT-PCR and flow cytometry were used to assess changes in mesoderm differentiation and gene expression in the final ECs as a result of strain. Functional outcomes of mechanically differentiated ECs were assessed with a tube formation assay and changes in H19. H19 was also overexpressed in human umbilical vein endothelial cells (HUVECs) to assess its role in non-H19-expressing ECs.

Results

Mechanical strain promoted mesoderm differentiation, marked by increased expression of brachyury 24 h after initiation of differentiation. Strain also increased expression of H19, CD31, VE-cadherin, and VEGFR2 in differentiated ECs. Strain-differentiated ECs formed tube networks with higher junction and endpoint density than statically-differentiated ECs. Overexpression of H19 in HUVECs resulted in similar patterns of tube formation.

Conclusions

H19 expression is increased by mechanical strain and promotes tube branching in iPSC-derived ECs.

中文翻译：

---

循环菌株促进 iPSC 衍生的内皮细胞中的 H19 表达和血管形成。

介绍

诱导多能干细胞 (iPSC) 衍生的内皮细胞 (ECs) 在多种心血管疾病中具有治疗应用的潜力。已知机械应变可调节 EC 行为和干细胞分化，并可能在指导 iPSC 的 EC 分化中发挥作用。H19是一种长链非编码 RNA (lncRNA)，已知会在几种机械相关的病理中影响 ECs，并且也可能在该过程中发挥作用。因此，我们研究了 EC 分化过程中机械刺激引起的H19的表达变化，以及对 EC 管形成的功能影响。

方法

iPSC 在 EC 分化过程中受到 5% 的循环机械应变。RT-PCR 和流式细胞术用于评估由于应变导致的最终 EC 中中胚层分化和基因表达的变化。通过管形成测定和H19的变化评估机械分化的 EC 的功能结果。H19也在人脐静脉内皮细胞 (HUVEC) 中过表达，以评估其在不表达H19的 EC 中的作用。

结果

机械应变促进中胚层分化，其标志是在分化开始后 24 小时 brachyury 的表达增加。菌株还在分化的EC中增加了H19、CD31、VE-钙粘蛋白和VEGFR2的表达。应变分化的 EC 形成的管网络比静态分化的 EC 具有更高的结和端点密度。H19在 HUVEC 中的过表达导致类似的管形成模式。

结论

H19表达因机械应变而增加，并促进 iPSC 衍生的 EC 中的管分支。