Original article Combining pharmacological mobilization with intramyocardial delivery of bone marrow cells over-expressing VEGF is more effective for cardiac repair Yigang Wang, Husnain K. Haider, Nauman Ahmad, Meifeng Xu, Ruowen Ge, Muhammad Ashraf * Department of Pathology and Laboratory Medicine, University of Cincinnati, College of Medicine, 231 Albert Sabin Way, Cincinnati, Ohio 45267, USA Received 4 January 2006; accepted 7 February 2006 Abstract We postulated that combining cell based hVEGF165 gene delivery with cytokine-induced mobilization of bone marrow cells (BMC) may give better prognosis in an infarcted heart. Forty-eight myoabalated female C57BL/6J mice (20–25 g) received 1 × 10 6 BMC from transgenic GFP+ male mice. One month later, acute myocardial infarction (MI) model was developed by coronary artery ligation. Animals were grouped (N = 12) to receive intramyocardial injections of 10 μl DMEM without cells (group 1; group 2) or with 1 × 10 5 mesenchymal stem cells (MSC) over-expressing hVEGF165 (group 3; group 4). The animals received either cytokine therapy (group 2 and 4) or saline solution (group 1 and 3) for 7 days after MI. Hemodynamic data were obtained 4 weeks after MI using Millar’sP–V system and cardiac tissue was harvested for im- munohistological studies. We observed regeneration and extensive survival of BMC in and around the infarcted myocardium in groups 3 and 4. Blood vessel density was markedly enhanced in group 4 as compared with groups 1 and 2 in peri-infarct area. Fibrotic area was significantly reduced with improved LV-contractile function in group 2 and 4. LV-systolic and diastolic functions were well-preserved in group 4 as indicated by +dP/dt, –dP/dt and Tau (glantz). We therefore conclude that transplantation of MSC overexpressing VEGF combined with cytokine induced BMC mobilization is superior to either of the monotherapy approach for angiomyogenesis and LV-function recovery. © 2006 Elsevier Ltd. All rights reserved. Keywords: Angiogenesis; Bone marrow stem cells; Cytokines; Heart infarction; Myocyte regeneration 1. Introduction The malleable nature of BMC with multilineage potential has been exploited for their ability to achieve cardiomyocyte phenotype for heart muscle regeneration [1,2]. The number of BMC mobilized intrinsically in response to cardiac injury is too small to fully replenish the lost cardiomyocytes in the ab- sence of an outside intervention. Pharmacological mobilization using various cytokines and growth factors egress stem cells from their bone marrow (BM) niches and shifts their homeo- static balance favorably in the peripheral circulation. The blood borne stem cells then home on to injured myocardium, enhance cardiac tissue regeneration and improve cardiac function after MI [3,4]. Granulocyte colony-stimulating factor (G-CSF) and stem cell factor (SCF) are regulators of granulopoiesis and critically regulate proliferation, differentiation, and survival of myeloid progenitor cells [5]. They are angiogenic cytokines and dis- tinctly enhance egress of hematopoietic stem cells (HSC) into the peripheral blood circulation [6] and engraftment following non-myoablative total-body irradiation [7]. Intramyocardial injection of stem cells from skeletal muscle and BM origin, with or without genetic modulation to over- express angiogenic growth factors lead to better prognosis in animal models [8,9] In a recent report, Matsumoto et al. [10] have shown that transplantation of VEGF over-expressing BM derived MSC could enhance the cardioprotective effects of MSC, followed by angiogenic effects in salvaging host myo- cardium. A more interesting approach was adopted by Kawa- moto et al. [32] who delivered VEGF2 gene by intramyocardial injection of adenoviral vector encoding for VEGF2 together with cytokine-induced mobilization of BMC. The synergistic www.elsevier.com/locate/yjmcc Journal of Molecular and Cellular Cardiology 40 (2006) 736–745 * Corresponding author. Tel.: +1 513 558 0145; fax: +1 513 558 0807. E-mail address: Muhammad.Ashraf@UC.Edu (M. Ashraf). 0022-2828/$ - see front matter © 2006 Elsevier Ltd. All rights reserved. doi:10.1016/j.yjmcc.2006.02.004