title: The heme oxygenase 1 inducer (CoPP) protects human cardiac stem cells against apoptosis through activation of the extracellular signal-regulated kinase (ERK)/NRF2 signaling pathway and cytokine release.
abstract: Intracoronary delivery of c-kit-positive human cardiac stem cells (hCSCs) is a promising approach to repair the infarcted heart, but it is severely limited by the poor survival of donor cells. Cobalt protoporphyrin (CoPP), a well known heme oxygenase 1 inducer, has been used to promote endogenous CO generation and protect against ischemia/reperfusion injury. Therefore, we determined whether preconditioning hCSCs with CoPP promotes CSC survival. c-kit-positive, lineage-negative hCSCs were isolated from human heart biopsies. Lactate dehydrogenase release assays demonstrated that preconditioning CSCs with CoPP markedly enhanced cell survival after oxidative stress induced by H(2)O(2), concomitant with up-regulation of heme oxygenase 1, COX-2, and anti-apoptotic proteins (BCL2, BCL2-A1, and MCL-1) and increased phosphorylation of NRF2. Apoptotic cytometric assays showed that pretreatment of CSCs with CoPP enhanced the cells' resistance to apoptosis induced by oxidative stress. Conversely, knocking down HO-1, COX-2, or NRF2 by shRNA gene silencing abrogated the cytoprotective effects of CoPP. Further, preconditioning CSCs with CoPP led to a global increase in release of cytokines, such as EGF, FGFs, colony-stimulating factors, and chemokine ligand. Conditioned medium from cells pretreated with CoPP conferred naive CSCs remarkable resistance to apoptosis, demonstrating that cytokines released by preconditioned cells play a key role in the anti-apoptotic effects of CoPP. Preconditioning CSCs with CoPP also induced an increase in the phosphorylation of Erk1/2, which are known to modulate multiple pro-survival genes. These results potentially provide a simple and effective strategy to enhance survival of CSCs after transplantation and, therefore, their efficacy in repairing infarcted myocardium.
authors.affiliation: Department of Medicine, Institute of Molecular Cardiology, University of Louisville, Louisville, Kentucky 40292, USA.
authors.forename: Chuanxi
authors.initials: C
authors.lastname: Cai
authors.forename: Lei
authors.initials: L
authors.lastname: Teng
authors.forename: Duc
authors.initials: D
authors.lastname: Vu
authors.forename: Jia-Qiang
authors.initials: JQ
authors.lastname: He
authors.forename: Yiru
authors.initials: Y
authors.lastname: Guo
authors.forename: Qianghong
authors.initials: Q
authors.lastname: Li
authors.forename: Xian-Liang
authors.initials: XL
authors.lastname: Tang
authors.forename: Gregg
authors.initials: G
authors.lastname: Rokosh
authors.forename: Aruni
authors.initials: A
authors.lastname: Bhatnagar
authors.forename: Roberto
authors.initials: R
authors.lastname: Bolli
mesh_terms: D017209:Apoptosis; D016207:Cytokines / Q000378:metabolism*; D048049:Extracellular Signal-Regulated MAP Kinases / Q000378:metabolism*; D006331:Heart Diseases / Q000188:drug therapy*; D051547:Heme Oxygenase-1 / Q000737:chemistry*; D006801:Humans; D007770:L-Lactate Dehydrogenase / Q000378:metabolism; D016086:Lentivirus / Q000378:metabolism; D008957:Models, Genetic; D017202:Myocardial Ischemia / Q000473:pathology; D009206:Myocardium / Q000166:cytology*; D051267:NF-E2-Related Factor 2 / Q000378:metabolism*; D018384:Oxidative Stress; D011524:Protoporphyrins / Q000494:pharmacology*; D034741:RNA, Small Interfering / Q000378:metabolism; D013234:Stem Cells / Q000166:cytology*
chemical_list: D016207:Cytokines; D051267:NF-E2-Related Factor 2; C495635:NFE2L2 protein, human; D011524:Protoporphyrins; D034741:RNA, Small Interfering; C007095:cobaltiprotoporphyrin; D007770:L-Lactate Dehydrogenase; D051547:Heme Oxygenase-1; D048049:Extracellular Signal-Regulated MAP Kinases