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Increased oxygen consumption and OXPHOS potential in superhealer mesenchymal stem cells.

Hughey CC, Alfaro MP, Belke DD, Rottman JN, Young PP, Wasserman DH, Shearer J - Cell Regen (Lond) (2012)

Bottom Line: Additionally, glutamate/malate succinate-supported oxygen consumption in permeabilized cells was elevated approximately 1.25- and 1.4-fold in the MRL-MSCs, respectively.The results from intact and permeabilized MSCs indicate MRL-MSCs exhibit a greater reliance on and capacity for aerobic metabolism.The greater capacity for oxidative metabolism may provide a protective effect by increasing ATP synthesis per unit substrate and prevent glycolysis-mediated acidosis and subsequent cell death upon transplantation into the glucose-and oxygen-deprived environment of the infarcted heart.

View Article: PubMed Central - PubMed

Affiliation: Department of Biochemistry and Molecular Biology, Faculty of Medicine, University of Calgary, Calgary, AB T2N 1N4 Canada ; University of Calgary, KNB Rm 3318. 2500 University Dr. NW, Calgary, Alberta Canada T2N 1N4.

ABSTRACT

Background: Cell-based therapies show promise in repairing cardiac tissue and improving contractile performance following a myocardial infarction. Despite this, ischemia-induced death of transplanted cells remains a major hurdle to the efficacy of treatment. 'Superhealer' MRL/MpJ mesenchymal stem cells (MRL-MSCs) have been reported to exhibit increased engraftment resulting in reduced infarct size and enhanced contractile function. This study determines whether intrinsic differences in mitochondrial oxidative phosphorylation (OXPHOS) assist in explaining the enhanced cellular survival and engraftment of MRL-MSCs.

Findings: Compared to wild type MSCs (WT-MSCs), mitochondria from intact MRL-MSCs exhibited an increase in routine respiration and maximal electron transport capacity by 2.0- and 3.5-fold, respectively. When routine oxygen utilization is expressed as a portion of maximal cellular oxygen flux, the MRL-MSCs have a greater spare respiratory capcity. Additionally, glutamate/malate succinate-supported oxygen consumption in permeabilized cells was elevated approximately 1.25- and 1.4-fold in the MRL-MSCs, respectively.

Conclusion: The results from intact and permeabilized MSCs indicate MRL-MSCs exhibit a greater reliance on and capacity for aerobic metabolism. The greater capacity for oxidative metabolism may provide a protective effect by increasing ATP synthesis per unit substrate and prevent glycolysis-mediated acidosis and subsequent cell death upon transplantation into the glucose-and oxygen-deprived environment of the infarcted heart.

No MeSH data available.


Related in: MedlinePlus

Oxygen flux in intact wild-type mesenchymal stem cells (WT-MSC) and MRL/MpJ mesenchymal stem cells (MRL-MSC). (A) RDMEM, LEAK and ETS oxygen consumption in intact WT-MSC and MRL-MSC. RDMEM represents routine respiration, LEAK represents oxygen consumption independent of ADP phosphorylation and ETS indicates maximal electron transport capacity. (B) Flux control ratios (FCR). Ratios of oxygen flux in differing respiratory control states, normalized to a defined reference respiratory state. n = 6, data are mean ± S.E.M. *p < 0.05 vs. WT-MSC.
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Fig1: Oxygen flux in intact wild-type mesenchymal stem cells (WT-MSC) and MRL/MpJ mesenchymal stem cells (MRL-MSC). (A) RDMEM, LEAK and ETS oxygen consumption in intact WT-MSC and MRL-MSC. RDMEM represents routine respiration, LEAK represents oxygen consumption independent of ADP phosphorylation and ETS indicates maximal electron transport capacity. (B) Flux control ratios (FCR). Ratios of oxygen flux in differing respiratory control states, normalized to a defined reference respiratory state. n = 6, data are mean ± S.E.M. *p < 0.05 vs. WT-MSC.

Mentions: The initial incubation in culture medium allowed for determination of RDMEM. RDMEM in WT-MSCs was 33.1 ± 2.5 pmol O2/s/106 cells (Figure 1A). MRL-MSC RDMEM was elevated at 69.4 ± 3.9 pmol O2/s/106 cells (Figure 1A). Oligomycin-induced LEAK respiration allowed for determination of non-ADP phosphorylating oxygen utilization. LEAK respiration similar between WT-MSCs compared to the MRL-MSCs, 11.7 ± 1.2 vs. 20.0 ± 1.6 pmol O2/s/106 cells (Figure 1A). Maximal capacity of the electron transport system (ETS) differed between cell types. In intact WT-MSCs, the ETS of 54.4 ± 7.4 pmol O2/s/106 cells was lower than the MRL-MSCs ETS of 190.1 ± 15.3 pmol O2/s/106 cells (Figure 1A). These results indicate that absolute oxygen flux in the routine repiratory state and maximal respiratory rate are elevated in the MRL-MSCs.Figure 1


Increased oxygen consumption and OXPHOS potential in superhealer mesenchymal stem cells.

Hughey CC, Alfaro MP, Belke DD, Rottman JN, Young PP, Wasserman DH, Shearer J - Cell Regen (Lond) (2012)

Oxygen flux in intact wild-type mesenchymal stem cells (WT-MSC) and MRL/MpJ mesenchymal stem cells (MRL-MSC). (A) RDMEM, LEAK and ETS oxygen consumption in intact WT-MSC and MRL-MSC. RDMEM represents routine respiration, LEAK represents oxygen consumption independent of ADP phosphorylation and ETS indicates maximal electron transport capacity. (B) Flux control ratios (FCR). Ratios of oxygen flux in differing respiratory control states, normalized to a defined reference respiratory state. n = 6, data are mean ± S.E.M. *p < 0.05 vs. WT-MSC.
© Copyright Policy
Related In: Results  -  Collection

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Fig1: Oxygen flux in intact wild-type mesenchymal stem cells (WT-MSC) and MRL/MpJ mesenchymal stem cells (MRL-MSC). (A) RDMEM, LEAK and ETS oxygen consumption in intact WT-MSC and MRL-MSC. RDMEM represents routine respiration, LEAK represents oxygen consumption independent of ADP phosphorylation and ETS indicates maximal electron transport capacity. (B) Flux control ratios (FCR). Ratios of oxygen flux in differing respiratory control states, normalized to a defined reference respiratory state. n = 6, data are mean ± S.E.M. *p < 0.05 vs. WT-MSC.
Mentions: The initial incubation in culture medium allowed for determination of RDMEM. RDMEM in WT-MSCs was 33.1 ± 2.5 pmol O2/s/106 cells (Figure 1A). MRL-MSC RDMEM was elevated at 69.4 ± 3.9 pmol O2/s/106 cells (Figure 1A). Oligomycin-induced LEAK respiration allowed for determination of non-ADP phosphorylating oxygen utilization. LEAK respiration similar between WT-MSCs compared to the MRL-MSCs, 11.7 ± 1.2 vs. 20.0 ± 1.6 pmol O2/s/106 cells (Figure 1A). Maximal capacity of the electron transport system (ETS) differed between cell types. In intact WT-MSCs, the ETS of 54.4 ± 7.4 pmol O2/s/106 cells was lower than the MRL-MSCs ETS of 190.1 ± 15.3 pmol O2/s/106 cells (Figure 1A). These results indicate that absolute oxygen flux in the routine repiratory state and maximal respiratory rate are elevated in the MRL-MSCs.Figure 1

Bottom Line: Additionally, glutamate/malate succinate-supported oxygen consumption in permeabilized cells was elevated approximately 1.25- and 1.4-fold in the MRL-MSCs, respectively.The results from intact and permeabilized MSCs indicate MRL-MSCs exhibit a greater reliance on and capacity for aerobic metabolism.The greater capacity for oxidative metabolism may provide a protective effect by increasing ATP synthesis per unit substrate and prevent glycolysis-mediated acidosis and subsequent cell death upon transplantation into the glucose-and oxygen-deprived environment of the infarcted heart.

View Article: PubMed Central - PubMed

Affiliation: Department of Biochemistry and Molecular Biology, Faculty of Medicine, University of Calgary, Calgary, AB T2N 1N4 Canada ; University of Calgary, KNB Rm 3318. 2500 University Dr. NW, Calgary, Alberta Canada T2N 1N4.

ABSTRACT

Background: Cell-based therapies show promise in repairing cardiac tissue and improving contractile performance following a myocardial infarction. Despite this, ischemia-induced death of transplanted cells remains a major hurdle to the efficacy of treatment. 'Superhealer' MRL/MpJ mesenchymal stem cells (MRL-MSCs) have been reported to exhibit increased engraftment resulting in reduced infarct size and enhanced contractile function. This study determines whether intrinsic differences in mitochondrial oxidative phosphorylation (OXPHOS) assist in explaining the enhanced cellular survival and engraftment of MRL-MSCs.

Findings: Compared to wild type MSCs (WT-MSCs), mitochondria from intact MRL-MSCs exhibited an increase in routine respiration and maximal electron transport capacity by 2.0- and 3.5-fold, respectively. When routine oxygen utilization is expressed as a portion of maximal cellular oxygen flux, the MRL-MSCs have a greater spare respiratory capcity. Additionally, glutamate/malate succinate-supported oxygen consumption in permeabilized cells was elevated approximately 1.25- and 1.4-fold in the MRL-MSCs, respectively.

Conclusion: The results from intact and permeabilized MSCs indicate MRL-MSCs exhibit a greater reliance on and capacity for aerobic metabolism. The greater capacity for oxidative metabolism may provide a protective effect by increasing ATP synthesis per unit substrate and prevent glycolysis-mediated acidosis and subsequent cell death upon transplantation into the glucose-and oxygen-deprived environment of the infarcted heart.

No MeSH data available.


Related in: MedlinePlus