Tan Suat Cheng, Gomes Renata S M, Yeoh Kar Kheng, Perbellini Filippo, Malandraki-Miller Sophia, Ambrose Lucy, Heather Lisa C, Faggian Giuseppe, Schofield Christopher J, Davies Kay E, Clarke Kieran, Carr Carolyn A
Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, UK.
Cell Transplant. 2016;25(1):35-53. doi: 10.3727/096368915X687697. Epub 2015 Mar 6.
Cardiosphere-derived cells (CDCs), which can be isolated from heart explants, are a promising candidate cell source for infarcted myocardium regeneration. However, current protocols used to expand CDCs require at least 1 month in vitro to obtain sufficient cells for transplantation. We report that CDC culture can be optimized by preconditioning the cells under hypoxia (2% oxygen), which may reflect the physiological oxygen level of the stem cell niche. Under hypoxia, the CDC proliferation rate increased by 1.4-fold, generating 6 × 10(6) CDCs with higher expression of cardiac stem cell and pluripotency gene markers compared to normoxia. Furthermore, telomerase (TERT), cytokines/ligands involved in stem cell trafficking (SDF/CXCR-4), erythropoiesis (EPO), and angiogenesis (VEGF) were increased under hypoxia. Hypoxic preconditioning was mimicked by treatment with two types of hypoxia-inducible factor (HIF) prolyl-4-hydroxylase inhibitors (PHDIs): dimethyloxaloylglycine (DMOG) and 2-(1-chloro-4-hydroxyisoquinoline-3-carboxamido) acetic acid (BIC). Despite the difference in specificity, both PHDIs significantly increased c-Kit expression and activated HIF, EPO, and CXCR-4. Furthermore, treatment with PHDIs for 24 h increased cell proliferation. Notably, all hypoxic and PHDI-preconditioned CDCs had decreased oxygen consumption and increased glycolytic metabolism. In conclusion, cells cultured under hypoxia could have potentially enhanced therapeutic potential, which can be mimicked, in part, by PHDIs.
可从心脏外植体中分离得到的心肌球衍生细胞（CDCs）是梗死心肌再生中一种很有前景的候选细胞来源。然而，目前用于扩增CDCs的方案需要至少1个月的体外培养时间才能获得足够用于移植的细胞。我们报告称，通过在低氧（2%氧气）条件下对细胞进行预处理，可以优化CDC培养，这可能反映了干细胞微环境的生理氧水平。在低氧条件下，CDC增殖率提高了1.4倍，与常氧相比，可产生6×10⁶个具有更高心脏干细胞和多能性基因标志物表达的CDCs。此外，端粒酶（TERT）、参与干细胞转运的细胞因子/配体（SDF/CXCR - 4）、红细胞生成（EPO）和血管生成（VEGF）在低氧条件下均增加。用两种类型的缺氧诱导因子（HIF）脯氨酰-4-羟化酶抑制剂（PHDIs）：二甲基草酰甘氨酸（DMOG）和2 -（1 -氯-4 -羟基异喹啉-3 -羧酰胺基）乙酸（BIC）处理可模拟低氧预处理。尽管特异性存在差异，但两种PHDIs均显著增加c - Kit表达并激活HIF、EPO和CXCR - 4。此外，用PHDIs处理24小时可增加细胞增殖。值得注意的是，所有低氧和PHDI预处理的CDCs耗氧量均降低，糖酵解代谢增加。总之，在低氧条件下培养的细胞可能具有潜在增强的治疗潜力，这在一定程度上可由PHDIs模拟。
