| Autor: |
Campbell JM; Graduate School of Biomedical Engineering, University of New South Wales, Sydney, NSW 2052, Australia., Mahbub SB; Graduate School of Biomedical Engineering, University of New South Wales, Sydney, NSW 2052, Australia., Anwer AG; Graduate School of Biomedical Engineering, University of New South Wales, Sydney, NSW 2052, Australia., Habibalahi A; Graduate School of Biomedical Engineering, University of New South Wales, Sydney, NSW 2052, Australia., Gronthos S; Mesenchymal Stem Cell Laboratory, School of Biomedicine, Faculty of Health and Medical Sciences, University of Adelaide, Adelaide, SA 5000, Australia.; South Australian Health and Medical Research Institute, Adelaide, SA 5000, Australia., Paton S; Mesenchymal Stem Cell Laboratory, School of Biomedicine, Faculty of Health and Medical Sciences, University of Adelaide, Adelaide, SA 5000, Australia.; South Australian Health and Medical Research Institute, Adelaide, SA 5000, Australia., Grey ST; Garvan Institute of Medical Research, Darlinghurst, NSW 2010, Australia.; Faculty of Medicine, University of New South Wales, Sydney, NSW 2052, Australia., Wu LE; School of Biomedical Sciences, University of New South Wales, Sydney, NSW 2052, Australia., Gilchrist RB; School of Clinical Medicine, University of New South Wales, Sydney, NSW 2052, Australia., Goldys EM; Graduate School of Biomedical Engineering, University of New South Wales, Sydney, NSW 2052, Australia. |
| Abstrakt: |
Understanding the molecular mechanisms of differentiation is important for regenerative medicine and developmental biology. This study aims to characterise the role of the glycolysis/oxidative phosphorylation balance as a driver of mesenchymal stem cell (MSC) differentiation. Cells were maintained in normal conditions or stimulated towards the MSC trilineage cell types over 21 days. Multispectral imaging of cell autofluorescence was applied as a non-invasive methodology to continuously image cultures in situ. Spectral signals for collagen, NAD(P)H, and flavins were unmixed. MSCs cultured under chondrogenic conditions exhibited increased collagen levels relative to controls. Following osteogenic induction, MSCs showed increased collagen levels relative to controls during the earlier stages of culture; however, control cells increased their collagen levels as they became confluent. MSCs cultured under adipogenic conditions exhibited lower levels of collagen than controls. The redox ratio (RR; NAD(P)H/flavins) immediately decreased during chondrogenesis, with this early effect persisting throughout the culture compared to control cells, which appeared to increase their RR, similar to osteogenesis. Adipogenesis resulted in a small increase in RR on day 2 relative to control cells, followed by a persistent decrease. Chondrogenic and adipogenic differentiation favoured oxidative phosphorylation, whereas osteogenesis and MSC overgrowth resulted in a glycolytic metabolism. Following consideration of these findings, as well as the diverse reports in the literature, it is concluded that neither enhanced oxidative phosphorylation nor glycolysis are fundamental to the canonical modes of differentiation, and researchers should avoid interpreting shifts as indicating differentiation. |
