PEP-1-CAT-Transduced Mesenchymal Stem Cells Acquire an Enhanced Viability and Promote Ischemia-Induced Angiogenesis
et al. (2012) PEP-1-CAT-Transduced Mesenchymal Stem Cells Acquire an Enhanced Viability and
Promote Ischemia-Induced Angiogenesis. PLoS ONE 7(12): e52537. doi:10.1371/journal.pone.0052537
PEP-1-CAT-Transduced Mesenchymal Stem Cells Acquire an Enhanced Viability and Promote Ischemia-Induced Angiogenesis
Lei Zhang 0
Xiao-Wei Dong 0
Jia-Ning Wang 0
Jun-Ming Tang 0
Jian-Ye Yang 0
Ling-Yun Guo 0
Fei Zheng 0
Xia Kong 0
Yong-Zhang Huang 0
Shi-You Chen 0
Xin-Liang Ma, Thomas Jefferson University, United States of America
0 1 Institute of Clinical Medicine and Department of Cardiology, Renmin Hospital, Hubei University of Medicine , Shiyan, Hubei , People's Republic of China, 2 Key Lab of Human Embryonic Stem Cell of Hubei Province, Hubei University of Medicine , Hubei , People's Republic of China, 3 Department of Physiology, Hubei University of Medicine , Hubei , People's Republic of China, 4 Department of Physiology & Pharmacology, The University of Georgia , Athens, Georgia , United States of America
Objective: Poor survival of mesenchymal stem cells (MSC) compromised the efficacy of stem cell therapy for ischemic diseases. The aim of this study is to investigate the role of PEP-1-CAT transduction in MSC survival and its effect on ischemiainduced angiogenesis. Methods: MSC apoptosis was evaluated by DAPI staining and quantified by Annexin V and PI double staining and Flow Cytometry. Malondialdehyde (MDA) content, lactate dehydrogenase (LDH) release, and Superoxide Dismutase (SOD) activities were simultaneously measured. MSC mitochondrial membrane potential was analyzed with JC-1 staining. MSC survival in rat muscles with gender-mismatched transplantation of the MSC after lower limb ischemia was assessed by detecting SRY expression. MSC apoptosis in ischemic area was determined by TUNEL assay. The effect of PEP-1-CATtransduced MSC on angiogenesis in vivo was determined in the lower limb ischemia model. Results: PEP-1-CAT transduction decreased MSC apoptosis rate while down-regulating MDA content and blocking LDH release as compared to the treatment with H2O2 or CAT. However, SOD activity was up-regulated in PEP-1-CAT-transduced cells. Consistent with its effect on MSC apoptosis, PEP-1-CAT restored H2O2-attenuated mitochondrial membrane potential. Mechanistically, PEP-1-CAT blocked H2O2-induced down-regulation of PI3K/Akt activity, an essential signaling pathway regulating MSC apoptosis. In vivo, the viability of MSC implanted into ischemic area in lower limb ischemia rat model was increased by four-fold when transduced with PEP-1-CAT. Importantly, PEP-1-CAT-transduced MSC significantly enhanced ischemia-induced angiogenesis by up-regulating VEGF expression. Conclusions: PEP-1-CAT-transduction was able to increase MSC viability by regulating PI3K/Akt activity, which stimulated ischemia-induced angiogenesis.
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Funding: This study was supported by grants from National Natural Science Foundation of China (81170095),http://www.nsfc.gov.cn/Portal0/default152.htm;
Hubei Health Department Science Foundation (JX5B24),http://www.hbws.gov.cn/; Hubei Education Department Science Foundation (T201112),http://www.hbe.
gov.cn/.China; and National Institutes of Health (HL093429 and HL107526),http://www.nih.gov/. The funders had no role in study design, data collection and
analysis, decision to publish, or preparation of the manuscript.
Competing Interests: The authors have declared that no competing interests exist.
Ischemic diseases such as myocardial ischemia, cerebral
ischemia, and lower limb ischemia are a major threat to human
health. Stem cell therapy appears to be an effective treatment for
the ischemic diseases. Stem cells transplanted into damaged tissues
can differentiate into various functional cells including the cells
that form blood vessels [1], which replace or repair the damaged
tissue, improve blood supply [2], and reduce apoptosis and
necrosis caused by ischemia and hypoxia.
Mesenchymal stem cells (MSC) are bone marrow-derived cells
with multi-differentiation potential. Under certain conditions,
MSC can differentiate into cardiomyocytes, adipocytes,
osteoblasts, and neural cells, etc. [3]. Since MSC are easy to collect with
a high transient or stable transfection efficiency of exogenous genes
and a low immunogenicity, they are considered to be ideal
progenitor cells for cell transplantation. A large number of animal
and clinical trials have shown that MSC transplantation is safe and
effective in the treatment of ischemic diseases. The survival rate of
MSC transplanted into the ischemic region, however, is very low.
It is reported that nearly 99% of MSC were lost after 24 h of
transplantation [4]. Therefore, improving the survival rate of
transplanted MSC is one of the critical issues for stem cell-based
therapy.
Cells in ischemia or hypoxia environment produce a massive
amount of reactive oxygen species (ROS). Accumulation of ROS
causes cell apoptosis and necrosis, leading to tissue damage. ROS
including (...truncated)