Acellular Human Amniotic Membrane Scaffold with 15d-PGJ2 Nanoparticles in Postinfarct Rat Model.

The difficulty in the regeneration of cardiomyocytes after myocardial infarction is a major cause of heart failure. Together, the amniotic membrane and 15-deoxy-Δ12,14-prostaglandin J2 (15d-PGJ2) can help in the recovery of cardiomyocyte, as they present many growth factors and anti-inflammatory effect, respectively. The objective of this study is to compare the efficacy of Human Decellularized Amniotic Membrane Scaffold (AHAS) loaded with 15d-PGJ2 in improving ventricular function in a rat model of postinfarct ventricular dysfunction. Myocardial infarction was induced in 24 rats by left coronary occlusion. After a week, the animals were subjected to echocardiography for evaluation of left ventricle ejection fraction (LVEF), left ventricle end diastolic volume (LVEDV), and left ventricle end systolic volume (LVESV). Animals with ejection fraction <40% were included in the study and were randomized into three groups: control (n = 8), AHAS (n = 8) and AHAS +15d-PGJ2 (n = 8). In the AHAS group only the membrane was implanted, whereas in the AHAS +15d-PGJ2 the membrane +15d-PGJ2 was implanted on myocardial infarction. Echocardiographic evaluation was performed after 1 month. For histological analysis, heart tissue was stained with Gomori trichome, Sirius Red, the antibody against CD31 and connexin 43 (Cx43). There were no significant differences in the baseline LVEF, LVEDV, and LVESV in all groups. After 1 month, ejection fraction decreased in the control group but increased in the AHAS group and in the AHAS +15d-PGJ2 group in comparison with the control group. The LVEDV and LVESV in the AHAS and AHAS +15d-PGJ2 groups decreased compared with the control group, featuring a ventricular antiremodeling effect. Histopathology of the infarcted area identified the reduction of infarct size and collagen type 1 in the AHAS and AHAS +15d-PGJ2 groups. New blood vessels and cardiomyocytes have been identified in an infarcted area by CD31 and Cx43. AHAS +15d-PGJ2 provided an increase in the ejection fraction and prevented ventricular dilation in this postinfarction ventricular dysfunction model. Impact Statement Our study demonstrated reduction of myocardial fibrosis, proliferation of cardiomyocytes and increase in ejection fraction in rats after experimental acellular amniotic membrane scaffold (AHAS) carrying nanoparticles of 15d-PGJ2 scaffold engraftment in infarcted myocardium. AHAS grafts facilitated colonization of fibrotic myocardium regions with new contractile cells, in addition to preventing reduction of left ventricle wall thickness. This contribution is theoretically and practically relevant as current literature describes experimental studies performed on cardiac ischemic models which present conflicting results concerning cell types used in a research model.

Human Adipose-Derived Mesenchymal Stem Cells Cryopreservation and Thawing Decrease α4-Integrin Expression.

Aim. The effects of cryopreservation on adipose tissue-derived mesenchymal stem cells are not clearly documented, as there is a growing body of evidence about the importance of adipose-derived mesenchymal stem cells for regenerative therapies. The aim of this study was to analyze human adipose tissue-derived mesenchymal stem cells phenotypic expression (CD34, CD45, CD73, CD90, CD105, and CD49d), colony forming unit ability, viability, and differentiation potential before and after cryopreservation. Materials and Methods. 12 samples of the adipose tissue were collected from a healthy donor using the liposuction technique. The cell isolation was performed by enzymatic digestion and then the cells were cultured up to passage 2. Before and after cryopreservation the immunophenotype, cellular viability analysis by flow cytometer, colony forming units ability, differentiation potential into adipocytes and osteoblasts as demonstrated by Oil Red O and Alizarin Red staining, respectively. Results. The immunophenotypic markers expression was largely preserved, and their multipotency was maintained. However, after cryopreservation, the cells decreased α4-integrin expression (CD49d), cell viability, and number of colony forming units. Conclusions. These findings suggest that ADMSC transplanted after cryopreservation might compromise the retention of transplanted cells in the host tissue. Therefore, further studies are warranted to standardize protocols related to cryopreservation to attain full benefits of stem cell therapy.

Efeito do exercício associado ao transplante de células-tronco sobre a função ventricular de ratos pós-infarto agudo do miocárdio / Effect of exercise associated with stem cell transplantation on ventricular function in rats after acute myocardial infarction

OBJETIVO: Avaliar o efeito da associação terapêutica entre o transplante autólogo de células-tronco e o exercício físico aquático, sobre a fração de ejeção do ventrículo esquerdo (FEVE) de ratos com disfunção ventricular pós-infarto agudo do miocárdio (IAM). MÉTODOS: Foram induzidos ao IAM, por ligadura da artéria coronária esquerda, 21 ratos Wistar. Os animais foram submetidos à ecocardiografia para avaliação da FEVE (%) e dos volumes diastólico e sistólico finais do ventrículo esquerdo (VDF, VSF, ml), randomizados e ao transplante das células-tronco mononucleares. Os animais foram divididos em quatro grupos: grupo sedentário sem células (n=5), sedentário com células (n=5), treinado sem células (n=5) e treinado com células (n=6). O treinamento físico foi iniciado 30 dias após o IAM e realizado em piscina adaptada durante 30 dias. No início e no final do protocolo de treinamento físico, foram realizadas dosagens de lactato. Os animais foram submetidos a nova ecocardiografia após 60 dias do IAM. RESULTADOS: Comparação dos valores de FEVE 30 dias e 60 dias pós-IAM, respectivamente: sedentário sem (35,20 ± 7,64% vs. 22,39 ± 4,56% P=0,026), com células (25,18 ± 7,73% vs. 23,85 ± 9,51% P=0,860) e no treinado sem (21,49 ± 2,70% vs. 20,71 ± 7,14% P=0,792), treinado com células (28,86 ± 6,68 vs. 38,43 ±7,56% P=0,062). Identificou-se a diminuição de fibras colágenas, nas regiões de fibrose miocárdica no grupo treinado com e sem células. CONCLUSÃO: A associação terapêutica entre exercício físico e o transplante autólogo de células-tronco foi benéfica contra as ações do remodelamento ventricular.

OBJECTIVE: To analyze the functional and anatomical-pathological effect of transplantation of bone marrow mononuclear cells associated to aquatic physical activity after myocardial infarction in rats. METHODS: Twenty-one rats were induced by myocardial infarction, through left coronary artery ligation. After a week, the animals were subjected to echocardiography for evaluation of left ventricle ejection fraction (LVEF, %) and dyastolic and end systolic volume of the left ventricle (EDV, ESV, ml), randomized and the transplantation of mononuclear stem cells. The animals were divided into four groups: sedentary group without cells (n=5), sedentary with cells (n=5), trained without cells (n=5) and trained with cells (n=6). The physical training was started 30 days after infarction and held in swimming during 30 days. At the beginning and at the end of the physical training protocol were held assay of lactate. The animals have been subjected to new echocardiography after 60 days of myocardial infarction. RESULTS: Two months after the transplant, were observed decrease in FE in the control group (35.2 to 23.54 P=0.022) and addition of LVEF and stabilization of ventricular remodeling in the group trained with cells (29.85 to 33.43% P=0.062 and 0.71 to 0.73 ml, P=0.776, respectively). Identified the reduction of collagen fibers, myocardial fibrosis regions in the group trained with and without cells. CONCLUSION: The group trained with cells improves ventricular function compared to the control group, suggesting the benefit of associated cell therapy will physical activity.

Controversies about the chromosomal stability of cultivated mesenchymal stem cells: their clinical use is it safe?

The usefulness of adult stem cells in research and therapeutic applications highly relies on their genomic integrity and stability. Many laboratories including ours have addressed this concern using methods such as karyotyping, Qbanding, fluorescent in situ hybridization, array CGH, flow cytometry and Pap test to evaluate number and structure of chromosomes and cellular phenotype. This review attempts to summarize the findings reported so far for the studies on chromosomal aberrations in adult stem cells and warrant to perform certain basic tests before transplantation to avoid any adverse reactions, which will thus aid in better therapeutic output after cellular transplantation in the treatment of various diseases.

Effect of exercise associated with stem cell transplantation on ventricular function in rats after acute myocardial infarction.

OBJECTIVE: To analyze the functional and anatomical-pathological effect of transplantation of bone marrow mononuclear cells associated to aquatic physical activity after myocardial infarction in rats. METHODS: Twenty-one rats were induced by myocardial infarction, through left coronary artery ligation. After a week, the animals were subjected to echocardiography for evaluation of left ventricle ejection fraction (LVEF, %) and dyastolic and end systolic volume of the left ventricle (EDV, ESV, ml), randomized and the transplantation of mononuclear stem cells. The animals were divided into four groups: sedentary group without cells (n=5), sedentary with cells (n=5), trained without cells (n=5) and trained with cells (n=6). The physical training was started 30 days after infarction and held in swimming during 30 days. At the beginning and at the end of the physical training protocol were held assay of lactate. The animals have been subjected to new echocardiography after 60 days of myocardial infarction. RESULTS: Two months after the transplant, were observed decrease in FE in the control group (35.2 to 23.54 P=0.022) and addition of LVEF and stabilization of ventricular remodeling in the group trained with cells (29.85 to 33.43% P=0.062 and 0.71 to 0.73 ml, P=0.776, respectively). Identified the reduction of collagen fibers, myocardial fibrosis regions in the group trained with and without cells. CONCLUSION: The group trained with cells improves ventricular function compared to the control group, suggesting the benefit of associated cell therapy will physical activity.