Spaceflight Activates Protein Kinase C Alpha Signaling and Modifies the Developmental Stage of Human Neonatal Cardiovascular Progenitor Cells
Spaceflight Activates Protein Kinase C Alpha Signaling and Modifies the Developmental Stage of Human Neonatal Cardiovascular Progenitor Cells
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DOI：
10.1089/scd.2017.0263
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发表时间：
2018-02-12
影响因子：
4
通讯作者：
Kearns-Jonker, Mary
中科院分区：
文献类型：
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作者：
Baio, Jonathan;Martinez, Aida F.;Kearns-Jonker, Mary
航天会影响宇航员的心血管功能;然而，它对心脏发育和构成心脏修复基础的干细胞的影响尚不清楚。因此，需要进一步研究，以揭示这种变化对人类健康的潜在相关性。利用模拟微重力（SMG）产生的二维旋转和培养在国际空间站（ISS）上，我们评估了机械卸载对人类新生儿心血管祖细胞（CPC）发育特性和信号传导的影响。在SMG培养6-7天和ISS培养12天后，我们分析了基因表达的变化。这两种环境都诱导了通常与心血管发育早期状态相关的基因的表达。为了理解这种变化发生的机制，我们评估了SMG培养的CPC中机械敏感性小RhoGTP酶的表达，并观察到RHOA和CDC 42水平的降低。考虑到这些分子对细胞内钙水平的影响，我们评估了非经典Wnt/钙信号传导的变化。在SMG下6-7天后，CPC表现出升高的WNT 5A和PRKCA水平。同样，ISS培养的CPC在30天后表现出钙处理和信号传导基因水平升高，这对应于蛋白激酶C α（PKC α），一种钙依赖性蛋白激酶激活。Akt被激活，而磷酸化细胞外信号调节激酶水平不变。为了探索钙诱导在新生儿CPC中的作用，我们在地球上使用hWnt 5a处理激活PKC α。随后，早期心血管发育标志物水平升高。由SMG和hWnt 5a处理诱导的转录物在窦房结内表达，这可能代表维持在其原始状态的胚胎心肌。钙信号对机械卸载敏感，并指导CPC的发育特性。在太空和地球上的进一步研究可能有助于完善CPC在干细胞治疗中的应用，并突出发育的分子事件。
Spaceflight impacts cardiovascular function in astronauts; however, its impact on cardiac development and the stem cells that form the basis for cardiac repair is unknown. Accordingly, further research is needed to uncover the potential relevance of such changes to human health. Using simulated microgravity (SMG) generated by two-dimensional clinorotation and culture aboard the International Space Station (ISS), we assessed the effects of mechanical unloading on human neonatal cardiovascular progenitor cell (CPC) developmental properties and signaling. Following 6-7 days of SMG and 12 days of ISS culture, we analyzed changes in gene expression. Both environments induced the expression of genes that are typically associated with an earlier state of cardiovascular development. To understand the mechanism by which such changes occurred, we assessed the expression of mechanosensitive small RhoGTPases in SMG-cultured CPCs and observed decreased levels of RHOA and CDC42. Given the effect of these molecules on intracellular calcium levels, we evaluated changes in noncanonical Wnt/calcium signaling. After 6-7 days under SMG, CPCs exhibited elevated levels of WNT5A and PRKCA. Similarly, ISS-cultured CPCs exhibited elevated levels of calcium handling and signaling genes, which corresponded to protein kinase C alpha (PKC alpha), a calcium-dependent protein kinase, activation after 30 days. Akt was activated, whereas phosphorylated extracellular signal-regulated kinase levels were unchanged. To explore the effect of calcium induction in neonatal CPCs, we activated PKC alpha using hWnt5a treatment on Earth. Subsequently, early cardiovascular developmental marker levels were elevated. Transcripts induced by SMG and hWnt5a-treatment are expressed within the sinoatrial node, which may represent embryonic myocardium maintained in its primitive state. Calcium signaling is sensitive to mechanical unloading and directs CPC developmental properties. Further research both in space and on Earth may help refine the use of CPCs in stem cell-based therapies and highlight the molecular events of development.