Preconditioning of Mesenchymal Stem Cells with Non-ToxicConcentration of Hydrogen Peroxide Against Oxidative StressInduced Cell Death: The Role of Hypoxia-Inducible Factor-1

Abstract

Purpose: To investigate the protective effect of preconditioning with non-toxic dose of hydrogenperoxide (H2O2) as a possible cell signaling molecule, against cell death induced by toxicconcentration of H2O2 or by serum deprivation in human Wharton’s jelly-derived mesenchymalstem cells (HWJ-MSCs) and underlying mechanisms.Methods: HWJ-MSCs were isolated and identified using flow cytometry. After finding non-toxicconcentration of H2O2, cells preconditioning was performed by H2O2 (20 μM) for 12 h and celltolerance against serum deprivation or toxic levels of H2O2 was assayed by MTT test. Effect ofpreconditioning on mRNA and protein expression of Akt-1, Bcl-2 and Bax were examined usingreverse transcription polymerase chain reaction (RT-PCR) and western blotting respectively. Roleof hypoxia-inducible factor (HIF)-1α was explored in presence HIF-1α inhibitor.Results: Preconditioning with 20 μM H2O2 for 12 h was non-toxic and decreased cell deathinduced by oxidative stress and serum deprivation in MSC cultures. However, the increasedtolerance reversed in the presence of inhibitor of HIF-1α. By regards to RT-PCR and westernblotting data, although expression of Akt-1, Bcl-2 and Bax was not change considerably butphosphorylated Akt-1 (pAkt-1) was up regulated after treatment with 20 μM H2O2 compared tocontrol group. Moreover after exposure to 100 μM H2O2, western blotting analysis showed thatcell pretreatment with 20 μM H2O2, decremented Bax/Bcl2 ratio and up-regulated HIF-1α andpAkt-1 compared to the control group.Conclusion: Increased tolerance of H2O2-pretreated cells led to the suggestion that transplantationof H2O2 preconditioned MSCs may improve therapeutic potential of stem cells in cell therapyprocedures.

Hydrogen Peroxide Preconditioning Promotes Protective Effects of Umbilical Cord Vein Mesenchymal Stem Cells in Experimental Pulmonary Fibrosis

“…Upregulation of several anti-apoptotic proteins, growth factors, cytokines and activation of some signaling pathways is involved in vitro H 2 O 2 effects, whereas there are few pieces of information in vivo investigations in this field. 27,29 Results of this work suggest that intratracheal transplantation of H 2 O 2 preconditioned hUCV-MSCs are more effective in decreasing connective tissue and collagen deposition and increasing alveolar space in the experimental PF model (Figures 4 and 5). In addition, H 2 O 2 treated MSCs are more effective in reducing TGF-β1 and α-SMA expression in fibrotic lung tissue ( Figures 6 and 7).…”

“…However, there was no significant difference between the two treated groups. (*** P < 0.001, ** P < 0.01) Nouri et al 29 noted that preconditioning of MSCs with 20 μM H 2 O 2 (12 h) improved cell resistance against lethal microenvironment via HIF-1α overexpression. Also, Bashiri et al 27 demonstrated that preconditioning with 15 μM (24 hours) has better protective effects than other concentrations of H 2 O 2 .…”

“…[40][41][42] Some studies reported that in vitro preconditioning of MSCs could promote essential features, such as survival, migration and tissue repair capacity of transplanted stem cells against harsh microenvironment. 14,25,[27][28][29] Regarding the previous studies and the necessity of conducting in vivo study, 27,29 our work is among the few studies ever done in this field on experimental animal models. 14,30 In the current study, we are the first to evaluate the anti-inflammatory and anti-fibrotic effects of H 2 O 2 preconditioned hUCV-MSCs in mice with PF induced by bleomycin.…”

“…Widespread studies have been accomplished regarding in vitro preconditioning on MSCs, but there is little information provided that investigate the effects of preconditioning of these cells in experimental animal models. 14,[25][26][27][28][29][30] In the present study, the anti-inflammatory and anti-fibrotic effects of H 2 O 2 preconditioned hUCV-MSCs were evaluated in a bleomycin-induced PF mice model.…”

Effect of Hypoxia Preconditioned Adipose-Derived Mesenchymal Stem Cell Conditioned Medium on Cerulein-Induced Acute Pancreatitis in Mice

“…In vitro pre-conditioning can improve the effects of MSC and CM via over-expression of cytoprotective genes. 34,40,41 Some notable studies demonstrated that hypoxic preconditioning increases the expression level of HIF-1α, which acts an important gene in the upregulation of cytoprotective factors. Previous studies reported that hypoxic conditions modulate the paracrine activity, upregulates the secretable factors and increases the protein levels of HP-MSCs similar to that of MSCs cultured in the normal conditions.…”