Abstract 977: Mesenchymal Stem Cell Therapy Prevents Ischemia/Reperfusion Injury and Promotes Tissue Regeneration

Abstract

Ischemic heart disease, especially myocardial infarction, is an important cause of heart failure. However, therapeutic potential of mesenchymal stem cells (MSC) for myocardial or pulmonary ischemia reperfusion (IR) injury is not well studied. Interleukin-10 (IL-10) is an anti-inflammatory cytokine. In this study MSC and IL-10 engineered MSC were tested for their ability to prevent IR injury and promote tissue repair. Methods: Bone marrow cells from Lewis rat were cultured in plastic tissue culture flasks for 72 hours; cells in suspension were discarded and the adherent cells (MSC) were expanded. MSC were transduced with r vIL-10-retrovirus and selected on neomycin (1mg/ml for 7 days). Experimental design: following 120 minutes of left lung ischemia, Group A, rats received vIL10 transduced MSC (∼15 x 10 6 ; i.v.); Group B, rats received empty vector engineered MSC; Group C, received MSC; and Group D, received saline. Group E received no ischemia or MSC. Left lung ischemia was performed by clamping left pulmonary artery/vein/bronchus at end inspiration. At 24h, 72 h, & 7 days following ischemia, blood was collected from left and right pulmonary veins, separately. Results : Mean blood oxygenation (PaO2/FIO2 ratio, mmHg) at day 7 was significantly (P<0.05) reduced following IR injury in Group B (161± 77) and Group D (181± 64), compared to MSC-vIL10 (404± 32; Group A) & MSC (294±103;Group C) treated animals. In Group E, PaO2/FIO2 was 440± 42mm Hg. Significant improvement in lung oxygenation with MSC and vIL-10 therapy was observed as early as 3 days. MSC produced vIL-10 (∼5ng/ml) ex vivo . HP of lungs demonstrated reduced PMN cells with MSC therapy. Inflammatory mediators IL-1a, MCP-1, MIP-1a, and IL1-b protein levels were markedly increased in the injured lung; their analysis in MSC treated groups are underway. I.V. injected Tg GFP+MSC trafficked to the lung & other tissues. VEGF & HGF mRNA in MSC was 66% & 43% of β-actin, respectively. Ex vivo expanded MSC were CD34-, CD45+ (5%), CD29+ (92%), CD80-, CD86+ (10%), CD90+ (∼90%), MHC Class I low & MHC Class II-. Conclusions: Autologous MSC therapy prevented IR injury and served as an excellent vehicle to deliver cytokine. MSC therapy to prevent IR injury and enhance tissue regeneration in cardiopulmonary diseases seems promising.