Preconditioning of Cardiosphere-Derived Cells With Hypoxia or Prolyl-4-Hydroxylase Inhibitors Increases Stemness and Decreases Reliance on Oxidative Metabolism.

Tan SC., Gomes RSM., Yeoh KK., Perbellini F., Malandraki-Miller S., Ambrose L., Heather LC., Faggian G., Schofield CJ., Davies KE., Clarke K., Carr CA.

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.

DOI

10.3727/096368915X687697

Type

Journal article

Journal

Cell Transplant

Publication Date

2016

Volume

25

Pages

35 - 53

Keywords

Animals, Biomarkers, Cell Differentiation, Cell Hypoxia, Cell Proliferation, Female, Gene Expression Regulation, Glucose, Hypoxia-Inducible Factor 1, alpha Subunit, Myocardium, Oxidation-Reduction, Prolyl Hydroxylases, Prolyl-Hydroxylase Inhibitors, RNA, Messenger, Rats, Sprague-Dawley, Spheroids, Cellular, Stem Cells

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