[Show abstract][Hide abstract] ABSTRACT: Mesenchymal stem cells (MSCs) hold great promise for use in cell-based therapies because of their multipotency and simple methods for in vitro expansion. However, during in vitro expansion, MSCs will age and lose their multipotency and proliferation capability. Previous studies have reported that calorie restriction (CR) increases proliferation of MSCs and decreases apoptosis. Therefore, in this study, we examined the effect of low glucose (LG) on human bone marrow-derived MSCs. Proliferation under low glucose (LG, 1.4 mM) conditions was compared with that under normal glucose (NG, 5.5 mM) conditions. In addition, comparative studies of population doubling (PD), β-galactosidase (β-GAL) activity, reactive oxygen species (ROS) generation and differentiation capacity (osteocytes and adipocytes) in NG and LG conditions were performed. In addition, protein expression patterns were compared between NG and LG conditions and several proteins were found to be up- or down-regulated under the glucose restriction condition (LG condition). As a result, CR does not seem to have a significant effect on proliferation, ROS generation, glucose consumption concentration, population doublings, and adipogenic differentiation of MSCs. Interestingly, however, the differentiation potential into osteocytes was maintained under CR and a lower senescence-associated β-galactosidase (β-GAL) activity was observed under CR than under the NG condition. In addition, we determined three up-regulated proteins (aldehyde dehydrogenase, neuropolyprptide h3, and prolyl 4-hydroxylase alpha subunit) and seven down-regulated proteins (laminin-binding protein, actin, sec 13 protein, alpha soluble N-ethylmaleimide-sensitive fusion protein (NSF)- attachment protein (SNAP), manganese superoxide dismutase, proteasome alpha 1 subunit, and ribosomal protein S12) via two-dimensional electrophoresis analysis. These results imply that differentially expressed proteins under the LG condition may provide further information on the aging and differentiation of stem cells.
No preview · Article · Feb 2012 · In Vitro Cellular & Developmental Biology - Animal
[Show abstract][Hide abstract] ABSTRACT: Stress induced premature senescence (SIPS) occurs after exposure to many different sublethal stresses including H(2)O(2), hyperoxia, or tert-butylhydroperoxide. Human mesenchymal stem cells (hMSCs) exhibit limited proliferative potential in vitro, the so-called Hayflick limit. According to the free-radical theory, reactive oxygen species (ROS) might be the candidates responsible for senescence and age-related diseases. H(2)O(2) may be responsible for the production of high levels of ROS, in which the redox balance is disturbed and the cells shift into a state of oxidative stress, which subsequently leads to premature senescence with shortening telomeres. H(2)O(2) has been the most commonly used inducer of SIPS, which shares features of replicative senescence (RS) including a similar morphology, senescence-associated β-galactosidase activity, cell cycle regulation, etc. Therefore, in this study, the senescence of hMSC during SIPS was confirmed using a range of different analytical methods. In addition, we determined five differentially expressed spots in the 2-DE map, which were identified as Annexin A2 (ANXA2), myosin light chain 2 (MLC2), peroxisomal enoyl-CoA hydratase 1 (ECH1), prosomal protein P30-33K (PSMA1) and mutant β-actin by ESI-Q-TOF MS/MS. Also, proton ((1)H) nuclear magnetic resonance spectroscopy (NMR) was used to elucidate the difference between metabolites in the control and hMSCs treated with H(2)O(2). Among these metabolites, choline and leucine were identified by (1)H-NMR as up-regulated metabolites and glycine and proline were identified as down-regulated metabolites.
No preview · Article · Mar 2011 · Experimental gerontology
[Show abstract][Hide abstract] ABSTRACT: Multipotent mesenchymal stem cells (MSCs) derived from human umbilical cord blood (hUCB) represent promising candidates for the development of future cellular therapy strategies. MSCs have been found to be able to differentiate into various tissues. One of the primary limitations in our understanding of the biology of human MSCs is the absence of prospective markers required for the monitoring of lineage-specific differentiation. hUCB-derived MSCs have been found to have significantly greater osteogenic potential. In this study, we focused on proteins that were differentially expressed during osteogenic differentiation of hUCB-MSCs. And we analyzed the protein expression inherent to osteogenic differentiation by two-dimensional gel electrophoresis, ESI-Q-TOF, and Western blotting. Eleven differentially expressed spots were observed between the two groups (before and after differentiation) on the 2-DE map. These might also be proved as useful cytosolic biomarker proteins for osteogenesis, and might be employed in quality control of osteoblasts in cell-therapy applications.
No preview · Article · Oct 2008 · Bioscience Biotechnology and Biochemistry
[Show abstract][Hide abstract] ABSTRACT: To study the change in hepatic stellate cell (HSC) function under diabetic conditions, we cultured rat HSC in the presence of 5 and 30 mM glucose, which correspond to blood glucose concentrations during the early and late stages of diabetes, respectively. The differentially expressed HSC proteins were analyzed using 2-DE and ESI-Q-TOF MS/MS and confirmed with Western blotting. The changed protein expression will provide greater understanding of glycolysis in HSC at the high concentration of glucose.