title: Preconditioning promotes survival and angiomyogenic potential of mesenchymal stem cells in the infarcted heart via NF-kappaB signaling.
abstract: We proposed that pharmacological manipulation of mesenchymal stem cells (MSCs) with diazoxide enhanced their survival and regenerative potential via NFkappaB regulation. MSCs preconditioned ((PC)MSCs) with diazoxide and later subjected to oxidant stress with 100 micromol/L H(2)O(2) either immediately or after 24 h exhibited higher survival (p < 0.01 vs nonpreconditioned MSCs; (Non-PC)MSCs) with concomitantly increased phosphorylation of PI3K, Akt, GSK3beta (cytoplasmic), and NF-kappaB (p65) (nuclear). Akt kinase activity was determined as a function of GSK3beta activity. Pretreatment of (PC)MSCs with Wortmannin (Wt), NEMO-binding domain (NBD), or NF-kappaB (p50) siRNA abolished NF-kappaB (p65) activity. Preconditioning increased NF-kappaB-dependent elevation of secretable growth factors associated with their paracrine effects. Inhibition of PI3K activity with Wt reduced (PC)MSCs viability at both early and 24 h time-points. However, inhibition of NF-kappaB reduced viability of (PC)MSCs only at 24 h time-point. For in vivo studies, DMEM without cells (group-1) or containing 1 x 10(6) male (Non-PC)MSCs (group-2), (PC)MSCs (group-3), (PC)MSCs pretreated with Wortmannin (group-4) or NF-kappaB decoy (group-5) were transplanted in a female rat model of acute myocardial infarction. Group-3 showed highest cell survival and growth factor expression, increased angiomyogenesis, and functional improvement. We conclude that activation of NF-kappaB by preconditioning promoted (PC)MSCs survival and angiomyogenic potential in the infarcted heart.
authors.affiliation: Department of Pathology and Lab Medicine, 231 Albert Sabin Way, University of Cincinnati College of Medicine, Cincinnati, OH 45267-0529, USA. muhammad.ashraf@uc.edu
authors.forename: Muhammad R
authors.initials: MR
authors.lastname: Afzal
authors.forename: Husnain Kh
authors.initials: HKh
authors.lastname: Haider
authors.forename: Niagara Muhammad
authors.initials: NM
authors.lastname: Idris
authors.forename: Shujia
authors.initials: S
authors.lastname: Jiang
authors.forename: Rafeeq P H
authors.initials: RP
authors.lastname: Ahmed
authors.forename: Muhammad
authors.initials: M
authors.lastname: Ashraf
mesh_terms: D000730:Androstadienes / Q000494:pharmacology; D000818:Animals; D002470:Cell Survival / Q000187:drug effects; D003981:Diazoxide / Q000494:pharmacology; D004195:Disease Models, Animal; D004452:Echocardiography; D005260:Female; D020868:Gene Silencing; D006861:Hydrogen Peroxide / Q000494:pharmacology; D019157:Ischemic Preconditioning, Myocardial; D008297:Male; D059630:Mesenchymal Stem Cells / Q000166:cytology* / Q000187:drug effects; D009203:Myocardial Infarction / Q000378:metabolism*; D016328:NF-kappa B / Q000037:antagonists & inhibitors / Q000378:metabolism*; D018919:Neovascularization, Physiologic; D018384:Oxidative Stress / Q000187:drug effects; D051381:Rats; D011916:Rats, Inbred F344; D020133:Reverse Transcriptase Polymerase Chain Reaction; D015398:Signal Transduction; D000077191:Wortmannin
chemical_list: D000730:Androstadienes; D016328:NF-kappa B; D006861:Hydrogen Peroxide; D003981:Diazoxide; D000077191:Wortmannin