Combining angiogenic gene and stem cell therapies for myocardial infarction
ABSTRACT Transplantation of stem cells from various sources into infarcted hearts has the potential to promote myocardial regeneration. However, the regenerative capacity is limited partly as a result of the low survival rate of the transplanted cells in the ischemic myocardium. In the present study, we tested the hypothesis that combining cell and angiogenic gene therapies would provide additive therapeutic effects via co-injection of bone marrow-derived mesenchymal stem cells (MSCs) with an adeno-associated viral vector (AAV), MLCVEGF, which expresses vascular endothelial growth factor (VEGF) in a cardiac-specific and hypoxia-inducible manner.
MSCs isolated from transgenic mice expressing green fluorescent protein and MLCVEGF packaged in AAV serotype 1 capsid were injected into mouse hearts at the border of ischemic area, immediately after occlusion of the left anterior descending coronary, individually or together. Engrafted cells were detected and quantified by real-time polymerase chain reaction and immunostaining. Angiogenesis and infarct size were analyzed on histological and immunohistochemical stained sections. Cardiac function was analyzed by echocardiography.
We found that co-injection of AAV1-MLCVEGF with MSCs reduced cell loss. Although injection of MSCs and AAV1-MLCVEGF individually improved cardiac function and reduced infarct size, co-injection of MSC and AAV1-MLCVEGF resulted in the best improvement in cardiac function as well as the smallest infarct among all groups. Moreover, injection of AAV1-MLCVEGF induced neovasculatures. Nonetheless, injection of MSCs attracted endogenous stem cell homing and increased scar thickness.
Co-injection of MLCVEGF and MSCs in ischemic hearts can result in better cardiac function and MSC survival, compared to their individual injections, as a result of the additive effects of each therapy.
- SourceAvailable from: Mahmood S Choudhery
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- "Since the preferred sources of stem cells in most clinical trials are autologous, the factors that contribute to changes in MSCs with age require investigation (Yu et al., 2011). MSCs can secrete cytokines that encourage angiogenesis and inhibit apoptosis (Kang et al., 2009; Pons et al., 2009). The protective role of Sirt1 may be a normal function of endothelial cells (Potente et al., 2007; Ota et al., 2008), but to our knowledge its impact in MSCs has not yet studied. "
ABSTRACT: Decline in the function of stem cells with age, such as other cells of the body, results in an imbalance between loss and renewal. Increasing age of the donor thus diminishes the effectiveness of MSCs (mesenchymal stem cells) transplantation in age-related diseases. The clinical use of stem cell therapies needs autologous stem cell transplantation; it is essential therefore to study the repair ability and survivability of cells before transplantation. Bone marrow derived MSCs possess multi-lineage differentiation potential, but aging adversely affects their therapeutic efficacy. MSCs from young (2-3 months) and aged (23-24 months) GFP (green fluorescent protein)-expressing C57BL/6 mice were isolated and their regenerative potential was assessed in vitro. Real-time RT-PCR (reverse transcriptase-PCR) showed significantly higher expression of Sirt1 in MSCs isolated from young than older animals. Down-regulation of VEGF (vascular endothelial growth factor), SDF-1 (stromal-cell-derived factor 1), AKT (also known as protein kinase B) and up-regulation of p53, p21, Bax and p16 occurred in aged cells. Tube formation, wound healing and proliferative abilities of the young MSCs were better than the aged MSCs. The results suggest that age-related increased expression of apoptotic and senescent genes, with concomitant decrease in Sirt1 gene expression, inhibits to some extent stem cell functioning.Cell Biology International 02/2012; 36(8):747-53. DOI:10.1042/CBI20110183 · 1.64 Impact Factor
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- "In MI, some early preclinical studies have reported significant therapeutic improvements that were associated with stem cell transplantation [3e5] but clinical trials have failed to translate these results into humans   . A potential reason for this failure is the very poor retention rate of stem cells transplanted into the ischemic myocardium; in a recent study, only 2% of injected stem cells remained within the injection zone after 7 days . It is possible that this poor retention of transplanted cells may be related to the inflammatory response associated with ischemia/reperfusion (IR) injury [12e15]. "
ABSTRACT: Stem cell transplantation has been suggested as a treatment for myocardial infarction, but clinical studies have yet to demonstrate conclusive, positive effects. This may be related to poor survival of the transplanted stem cells due to the inflammatory response following myocardial infarction. To address this, a scaffold-based stem cell delivery system was functionalised with anti-inflammatory plasmids (interleukin-10) to improve stem cell retention and recovery of cardiac function. Myocardial infarction was induced and these functionalised scaffolds were applied over the infarcted myocardium. Four weeks later, stem cell retention, cardiac function, remodelling and inflammation were quantified. Interleukin-10 gene transfer improved stem cell retention by more than five-fold and the hearts treated with scaffold, stem cells and interleukin-10 had significant functional recovery compared to the scaffold control (scaffold: -10 ± 7%, scaffold, interleukin-10 and stem cells: +7 ± 6%). This improved function was associated with increased infarcted wall thickness and increased ratios of collagen type III/type I, decreased cell death, and a change in macrophage markers from mainly cytotoxic in the scaffold group to mainly regulatory in scaffold, stem cells and interleukin-10 group. Thus, treatment of myocardial infarction with stem cells and interleukin-10 gene transfer significantly improved stem cell retention and ultimately improved overall cardiac function.Biomaterials 11/2011; 33(5):1303-14. DOI:10.1016/j.biomaterials.2011.10.019 · 8.31 Impact Factor
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ABSTRACT: Animal models that mimic cardiovascular diseases are indispensable tools for understanding the mechanisms underlying the diseases at the cellular and molecular level. This review focuses on various methods in preclinical research to create small animal models of cardiac diseases, such as myocardial infarction, dilated cardiomyopathy, heart failure, myocarditis and cardiac hypertrophy, and the related stem cell treatment for these diseases.The Open Cardiovascular Medicine Journal 11/2010; 4:231-9. DOI:10.2174/1874192401004010231