Preconditioning of Cardiosphere-Derived Cells With Hypoxia or Prolyl-4-Hydroxylase Inhibitors Increases Stemness and Decreases Reliance on Oxidative Metabolism.
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.
Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, UK.
Suat Cheng
SC
Tan
Renata S M
RS
Gomes
Kar Kheng
KK
Yeoh
Filippo
F
Perbellini
Sophia
S
Malandraki-Miller
Lucy
L
Ambrose
Lisa C
LC
Heather
Giuseppe
G
Faggian
Christopher J
CJ
Schofield
Kay E
KE
Davies
Kieran
K
Clarke
Carolyn A
CA
Carr
D000818:Animals; D015415:Biomarkers / Q000378:metabolism; D002454:Cell Differentiation / Q000187:drug effects; D015687:Cell Hypoxia / Q000187:drug effects; D049109:Cell Proliferation / Q000187:drug effects; D005260:Female; D005786:Gene Expression Regulation / Q000187:drug effects; D005947:Glucose / Q000378:metabolism; D051795:Hypoxia-Inducible Factor 1, alpha Subunit / Q000378:metabolism; D009206:Myocardium / Q000166:cytology*; D010084:Oxidation-Reduction / Q000187:drug effects; D064828:Prolyl Hydroxylases / Q000378:metabolism*; D064800:Prolyl-Hydroxylase Inhibitors / Q000494:pharmacology*; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D017207:Rats, Sprague-Dawley; D018874:Spheroids, Cellular / Q000166:cytology* / Q000187:drug effects / Q000378:metabolism*; D013234:Stem Cells / Q000166:cytology* / Q000187:drug effects / Q000378:metabolism
D015415:Biomarkers; D051795:Hypoxia-Inducible Factor 1, alpha Subunit; D064800:Prolyl-Hydroxylase Inhibitors; D012333:RNA, Messenger; D064828:Prolyl Hydroxylases; D005947:Glucose