Mesenchymal Stem Cells Pretreated with Delivered Hph-1-Hsp70 Protein Are Protected from Hypoxia-Mediated Cell Death and Rescue Heart Functions from Myocardial Injury

Abstract

Mesenchymal stem cell (MSC) therapy for myocardial injury has inherent limitations due to the poor viability of MSCs after cell transplantation. In this study, we directly delivered Hsp70, a protein with protective functions against stress, into MSCs, using the Hph-1 protein transduction domain ex vivo for high transfection efficiency and low cytotoxicity. Compared to control MSCs in in vitro hypoxic conditions, MSCs delivered with Hph-1-Hsp70 (Hph-1-Hsp70-MSCs) displayed higher viability and anti-apoptotic properties, including Bcl2 increase, reduction of Bax, JNK phosphorylation and caspase-3 activity. Hsp70 delivery also attenuated cellular ATPdepleting stress. Eight animals per group were used for in vivo experiments after occlusion of the left coronary artery.Transplantation of Hph-1-Hsp70-MSCs led to a decrease in the fibrotic heart area, and significantly reduced the apoptotic positive index by 19.5 6 2%, compared to no-treatment controls. Hph-1-Hsp70-MSCs were well-integrated into the infarcted host myocardium. The mean microvessel count per field in the infarcted myocardium of the Hph-1-Hsp70-MSCtreated group (122.1 6 13.5) increased relative to the MSCtreated group (75.9 6 10.4). By echocardiography, transplantation of Hph-1-Hsp70-MSCs resulted in additional increases in heart function, compared to the MSCs-transplanted group. Our results may help formulate better clinical strategies for in vivo MSC cell therapy for myocardial damage.

Cardiomyocytes from phorbol myristate acetate-activated mesenchymal stem cells restore electromechanical function in infarcted rat hearts

“…Yield was 3 × 10 6 cells (95% purity) after 2 wk of culture. Consistent with a previous report, the cultured MSCs expressed CD71, CD90, CD105, CD106, and ICAM-1, but not the hematopoietic and macrophage markers, CD34 and CD14, respectively (7,8).…”

“…Although preconditioning of MSCs, including genetic modification, has increased their therapeutic potency (6)(7)(8)20), the most obvious concern for clinical applications is how engrafted MSCs electromechanically integrate with host tissue (12).…”

“…Previously, we published studies focused on enhancing the survival of mesenchymal stem cells (MSCs) transplanted in the harsh pathologic conditions of an infarcted myocardium (6)(7)(8). However, we found that such MSC transplantation does not provide a proportional survival benefit compatible with significant improvement in cardiac contractile function.…”

Transcriptional Response to Hypoxia in the Aquatic Fungus Blastocladiella emersonii

“…(2). In mammalian cells, the induction of Hsp70 is HIF-1 dependent, and it was shown that this chaperone has a role in protection against hypoxia injury in tumor, renal, neuronal, and even mesenchymal stem cells (4,7,20,32,35,36,39,46,51). Induction of Hsp70 under hypoxia was also reported to occur in C. albicans (43) and C. neoformans (9).…”

Preparation and Characterization of Genetically Engineered Mesenchymal Stem Cell Aggregates for Regenerative Medicine

“…The use of animals was in accordance with the International Guide for the Care and Use of Laboratory Animals. Rat MSCs were harvested and propagated as described previously Chang et al, 2009). Briefly, the rat bone marrowderived cells were flushed out from femurs and tibias with culture medium (DMEM with 10% FBS).…”