Preconditioning by Mitochondrial Reactive Oxygen Species Improves the Proangiogenic Potential of Adipose-Derived Cells-Based Therapy
ABSTRACT Transplantation of adipose-derived stroma cells (ADSCs) stimulates neovascularization after experimental ischemic injury. ADSC proangiogenic potential is likely mediated by their ability to differentiate into endothelial cells and produce a wide array of angiogenic and antiapoptotic factors. Mitochondrial reactive oxygen species (ROS) have been shown to control ADSC differentiation. We therefore hypothesized that mitochondrial ROS production may change the ADSC proangiogenic properties.
The use of pharmacological strategies (mitochondrial inhibitors, antimycin, and rotenone, with or without antioxidants) allowed us to specifically and precisely modulate mitochondrial ROS generation in ADSCs. We showed that transient stimulation of mitochondrial ROS generation in ADSCs before their injection in ischemic hindlimb strongly improved revascularization and the number of ADSC-derived CD31-positive cells in ischemic area. Mitochondrial ROS generation increased the secretion of the proangiogenic and antiapoptotic factors, VEGF and HGF, but did not affect ADSC ability to differentiate into endothelial cells, in vitro. Moreover, mitochondrial ROS-induced ADSC preconditioning greatly protect ADSCs against oxidative stress-induced cell death.
Our study demonstrates that in vitro preconditioning by moderate mitochondrial ROS generation strongly increases in vivo ADSC proangiogenic properties and emphasizes the crucial role of mitochondrial ROS in ADSC fate.
SourceAvailable from: Maria Giovanna Scioli[Show abstract] [Hide abstract]
ABSTRACT: Homeostasis of adipose tissue requires highly coordinated response between circulating factors and cell population. Human adult adipose tissue-derived stem cells (ASCs) display multiple differentiation properties and are sensitive to insulin stimulation. Insulin resistance and high level of circulating insulin characterize patients with type 2 diabetes and obesity. At physiological concentration, insulin promoted proliferation and survival of ASCs in vitro, whereas high insulin level induced their dose-dependent proliferative arrest and apoptosis. Insulin-induced apoptotic commitment depended on the down-regulation of Erk-1, insulin growth factor-1 receptor (IGF-1R), and fibroblast growth factor receptor-1 (FGFR-1)-mediated signaling. Specific inhibition of Erk-1/2, IGF-1R, and FGFR activity promoted ASC apoptosis but did not increase insulin effects, whereas EGFR and ErbB2 inhibition potentiated insulin-induced apoptosis. FGFRs and EGFR inhibition reduced ASC adipogenic differentiation, whereas Erk-1/2 and IGF-1R inhibition was ineffective. Insulin-induced apoptosis associated to reactive oxygen species (ROS) accumulation and inhibition of NADPH oxidase 4 (Nox4) activity prevented ASC apoptosis. Moreover, specific inhibition of Erk-1/2, IGF-1R, and FGFR-1 activity promoted ROS generation and this effect was not cumulative with that of insulin alone. Our data indicate that insulin concentration is a critical regulatory switch between proliferation and survival of ASCs. High insulin level-induced apoptotic machinery involves Nox4-generated oxidative stress and the down-regulation of a complex receptor signaling, partially distinct from that influencing adipogenic differentiation of ASCs. J. Cell. Physiol. © 2014 Wiley Periodicals, Inc.Journal of Cellular Physiology 12/2014; 229(12). DOI:10.1002/jcp.24667 · 3.87 Impact Factor
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ABSTRACT: The inadequacy of existing therapeutic tools together with the paucity of organ donors have always led medical researchers to innovate the current treatment methods or to discover new ways to cure disease. Emergence of cell-based therapies has provided a new framework through which it has given the human world a new hope. Though relatively a new concept, the pace of advancement clearly reveals the significant role that stem cells will ultimately play in the near future. However, there are numerous uncertainties that are prevailing against the present setting of clinical trials related to stem cells: like the best route of cell administration, appropriate dosage, duration and several other applications. A better knowledge of these factors can substantially improve the effectiveness of disease cure or organ repair using this latest therapeutic tool. From a certain perspective, it could be argued that by considering certain proven clinical concepts and experience from synthetic drug system, we could improve the overall efficacy of cell-based therapies. In the past, studies on synthetic drug therapies and their clinical trials have shown that all the aforementioned factors have critical ascendancy over its therapeutic outcomes. Therefore, based on the knowledge gained from synthetic drug delivery systems, we hypothesize that by employing many of the clinical approaches from synthetic drug therapies to this new regenerative therapeutic tool, the efficacy of stem cell-based therapies can also be improved.Journal of Translational Medicine 09/2014; 12(1):243. DOI:10.1186/s12967-014-0243-9 · 3.99 Impact Factor
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ABSTRACT: The increase in adipocytes induced by chemotherapeutic drugs may play a negative role in hematopoietic recovery. However, the mechanism underlying adipocyte differentiation of mesenchymal stem cells (MSCs) in hematopoietic stress is still unknown. Hence, the involvement of reactive oxygen species (ROS) in adipocyte differentiation under hematopoietic stress was investigated in vitro and in vivo. The roles of cellular ROS in adipogenesis were investigated in vivo through an adipocyte hyperplasia marrow model under hematopoietic stress induced by arabinosylcytosine (Ara-C) and in vitro via adipocyte differentiation of human MSCs. ROS levels were detected using the CM-H2DCFDA probe and Mito-SOX dye. Adipogenesis was evaluated by histopathology and oil red O staining, whereas detection of mRNA levels of antioxidant enzymes and adipogenesis markers was performed using quantitative real-time polymerase chain reaction analysis. ROS were found to play an important role in regulating adipocyte differentiation of MSCs by activating peroxisome proliferator-activated receptor gamma (PPARγ,) while the antioxidant N-acetyl-L-cysteine acts through ROS to inhibit adipocyte differentiation. The elevated ROS levels induced by Ara-C were caused by both over-generation of mitochondrial ROS and reduction of antioxidant enzymes (Cu/Zn Superoxide dismutase and catalase). Our findings suggest that a mitochondrial-targeted antioxidant could diminish adipocyte differentiation.PLoS ONE 03/2015; 10(3):e0120629. DOI:10.1371/journal.pone.0120629 · 3.53 Impact Factor