Chunjuan Song1, Chunjing Song2, Fan Tong3. 1. Department of Physiology and Functional Genomics, College of Medicine, University of Florida, Gainesville, Florida, USA. Electronic address: songcj@ufl.edu. 2. Department of Experimental Education, Tianjin University of Traditional Chinese Medicine, Tianjin, China. 3. Department of Entomology and Nematology, College of Agricultural and Life Sciences, University of Florida, Gainesville, Florida, USA.
Abstract
BACKGROUND AIMS: Bone marrow-derived mesenchymal stromal cells (BMSCs) are being extensively investigated as cellular therapeutics for many diseases, including cardiovascular diseases. Although preclinical studies indicated that BMSC transplantation into infarcted hearts improved heart function, there are problems to be resolved, such as the low survival rate of BMSCs during the transplantation process and in the ischemic region with extreme oxidative stress. Autophagy plays pivotal roles in maintaining cellular homeostasis and defending against environmental stresses. However, the precise roles of autophagy in BMSCs under oxidative stress remain largely uncharacterized. METHODS: BMSCs were treated with H2O2, and autophagic flux was examined by means of microtubule-associated protein 1A/1B-light chain 3 II/I ratio (LC3 II/I), autophagosome formation and p62 expression. Cytotoxicity and cell death assays were performed after co-treatment of BMSCs by autophagy inhibitor (3-methyladenine) or autophagy activator (rapamycin) together with H2O2. RESULTS: We show that short exposure (1 h) of BMSCs to H2O2 dramatically elevates autophagic flux (2- to 4-fold), whereas 6-h prolonged oxidative treatment reduces autophagy but enhances caspase-3 and caspase-6-associated apoptosis. Furthermore, we show that pre- and co-treatment with rapamycin ameliorates H2O2-induced caspase-3 and caspase-6 activation and cell toxicity but that 3-methyladenine exacerbates H2O2-induced cell apoptotic cell death. CONCLUSIONS: Our results demonstrate that autophagy is critical for the survival of BMSCs under oxidative conditions. Importantly, we also suggest that the early induction of autophagic flux is possibly a self-defensive mechanism common in oxidant-tolerant cells.
BACKGROUND AIMS: Bone marrow-derived mesenchymal stromal cells (BMSCs) are being extensively investigated as cellular therapeutics for many diseases, including cardiovascular diseases. Although preclinical studies indicated that BMSC transplantation into infarcted hearts improved heart function, there are problems to be resolved, such as the low survival rate of BMSCs during the transplantation process and in the ischemic region with extreme oxidative stress. Autophagy plays pivotal roles in maintaining cellular homeostasis and defending against environmental stresses. However, the precise roles of autophagy in BMSCs under oxidative stress remain largely uncharacterized. METHODS: BMSCs were treated with H2O2, and autophagic flux was examined by means of microtubule-associated protein 1A/1B-light chain 3 II/I ratio (LC3 II/I), autophagosome formation and p62 expression. Cytotoxicity and cell death assays were performed after co-treatment of BMSCs by autophagy inhibitor (3-methyladenine) or autophagy activator (rapamycin) together with H2O2. RESULTS: We show that short exposure (1 h) of BMSCs to H2O2 dramatically elevates autophagic flux (2- to 4-fold), whereas 6-h prolonged oxidative treatment reduces autophagy but enhances caspase-3 and caspase-6-associated apoptosis. Furthermore, we show that pre- and co-treatment with rapamycin ameliorates H2O2-induced caspase-3 and caspase-6 activation and cell toxicity but that 3-methyladenine exacerbates H2O2-induced cell apoptotic cell death. CONCLUSIONS: Our results demonstrate that autophagy is critical for the survival of BMSCs under oxidative conditions. Importantly, we also suggest that the early induction of autophagic flux is possibly a self-defensive mechanism common in oxidant-tolerant cells.
Authors: Sailaja Ghanta; Konstantin Tsoyi; Xiaoli Liu; Kiichi Nakahira; Bonna Ith; Anna A Coronata; Laura E Fredenburgh; Joshua A Englert; Claude A Piantadosi; Augustine M K Choi; Mark A Perrella Journal: Am J Respir Cell Mol Biol Date: 2017-03 Impact factor: 6.914
Authors: Rajnikumar Sangani; Sudharsan Periyasamy-Thandavan; Rajneesh Pathania; Saif Ahmad; Ammar Kutiyanawalla; Ravindra Kolhe; Maryka H Bhattacharyya; Norman Chutkan; Monte Hunter; William D Hill; Mark Hamrick; Carlos Isales; Sadanand Fulzele Journal: Stem Cell Res Date: 2015-06-10 Impact factor: 2.020