Effect of platelet-rich plasma therapy associated with exercise training in musculoskeletal healing in rats.

BACKGROUND: Muscle healing is a time-dependent process associated with an increase in the total amount of local collagen fibers. Platelet-rich plasma therapy (PRPT) associated with exercise may improve this healing process. The aim of this study was to demonstrate the regenerative effect of PRPT in association with exercise training on musculoskeletal healing. METHODS: Male Wistar rats were submitted to an injury in the vastus lateralis muscle and randomly divided into 4 groups (n = 5/group): sedentary sham-operated (SSO); sedentary group submitted to PRPT (SPR); swim-trained (SWT); and swim-trained group submitted to PRPT (SWP). Serum lactate level was used to confirm the training protocol effectiveness to increase aerobic fitness. The collagen fiber concentration was measured by the polarization colors in picrosirius red-stained tissue sections. RESULTS: Lactate levels decreased in both training groups (SWT and SWP; P < .05) after training (SWT: from 6.2 ± 0.44 to 4.7 ± 0.22 mmol/L; SWP: from 5.5 ± 0.99 to 4.0 ± 0.78 mmol/L). There were less type 1 collagen fibers in SWP group compared with other groups (SSO = 31.8 ± 10.3, SSP = 32.3 ± 13.5, SWT = 14.6 ± 13.4, SWP = 5.7 ± 4.7, P < .05), while there were more type 3 collagen fibers on SWP (SSO = 68.7 ± 9.8, SSP = 71.2 ± 12.2, SWT = 85.4 ± 13.4, SWP = 94.4 ± 4.6, P < .05) in the injured region. CONCLUSION: Exercise in association with PRPT enhances the skeletal muscle-healing process.

Angiogenesis without functional outcome after mononuclear stem cell transplant in a doxorubicin-induced dilated myocardiopathy murine model.

OBJECTIVES: Cell transplantation is considered a novel approach in the treatment of myocardiopathy. The objective of this study was to evaluate the effects of autologous mononuclear stem cell therapy in doxorubicin-induced dilated myocardiopathy by conducting both functional and histopathologic analysis. METHODS: Seventy male rats were doxorubicin injected intraperitoneally for 2 weeks. At 1 month, the animals that had demonstrated left ventricular ejection fractions less than 40% were randomly divided into a mononuclear stem cell group and controls. Mononuclear stem cells were isolated. All animals underwent echocardiographic study: baseline, pre-cell therapy, and at 1 month post-cell therapy, and analyzed by the nonparametric Mann-Whitney test. Transplants were performed by subepicardial injections. Standard staining was performed. RESULTS: Twenty-three animals were randomly treated: mononuclear stem cell and control groups, with 11 rats completing the study. Cell viability was 85%. Mononuclear stem cells (n=5; 5x106 cells /300 microL medium) and control (n=6; 300 microL medium) were used. The resulting left ventricular ejection fraction in the cell therapy group was not significantly different compared with controls (p=0.54). New vessels were demonstrated in the subepicardial region. CONCLUSIONS: Autologous mononuclear stem cell therapy was not functionally effective in doxorubicin-induced dilated myocardiopathy in the animal model under study with the experimental conditions, despite occurrence of angiogenic activity.

Functional outcome of bone marrow stem cells (CD45(+)/CD34(-)) after cell therapy in chronic spinal cord injury in Wistar rats.

BACKGROUND: Therapy with diverse cell types has been proposed to regenerate spinal cord injuries seeking to minimize the consequences for the lives of chronic patients. The types considered are: mononuclear and mesenchymal adult stem cells, embryonic stem cells, and Schwann cells. MATERIALS AND METHODS: Ninety male Wistar rats that underwent spinal cord contusion injury (NYU Impactor) were followed with the Basso, Beattie, and Bresnahan (BBB) locomotor rating scale for 14 days. Animals with scores < or = 16 were randomly divided into 2 groups: control (vehicle) versus cell therapy group. The mononuclear fraction (CD45(+)/CD34(-)) obtained by puncture-aspiration of the bone marrow was isolated by a density gradient (d = 1.077). The parenchymal cell infusion was performed using a syringe (100 U/1 mL) with a 30G1/2 needle. The animals were followed for 10 days before euthanasia. Statistical analyses comparing groups were performed by the Mann-Whitney test and group comparisons by the Wilcoxon test. RESULTS: Among 90 injured rats, 65 (72.2%) survived, including 44 whose scores were < or = 16. Eleven animals finished the study in the control group (64.7%) and 17 in the therapy group (80.9%). The statistical analyses did not demonstrate significance (P > .05) for either test. CONCLUSION: Mononuclear adult stem cell therapy was not demonstrated to be functionally effective for chronic spinal cord injury.

Immunophenotypic expression by flow cytometric analysis of cocultured skeletal muscle and bone marrow mesenchymal stem cells for therapy into myocardium.

The product generated by skeletal muscle and bone marrow mesenchymal stem cell cocultures has been demonstrated to improve the functional outcomes after cell therapy in postinfarction or Chagas myocardiopathy. This coculture method allows cell interactions in vitro, diminishing the operational costs of the culture/expansion as well as leading to angiogenesis and myogenesis for regeneration of the injured heart. Flow cytometric analysis may better characterize the cellular types in this model. Our objective was to use flow cytometry to analyze the immunophenotype expressed in this coculture model. The coculture was performed in accordance with Carvalho for 21 days. Flow cytometry was performed before and after coculture to characterize the immunophenotypic profile of cellular subsets, namely, the surface markers CD31, CD34, CD44H, CD45, CD49d, CD54, CD73, CD90, CD105, CD106, Myo-D, M-cadherin, and Connexin-43. Statistics were performed by the nonparametric Friedman test (P < .05) with post-hoc analysis by the nonparametric Wilcoxon test (P < or = .017, Bonferroni correction). The results demonstrated statistical significance for CD45(+) in 89.49% of mononuclear cells, 3.58% in skeletal muscle cells, and 4.74% among cocultured cells (P = .0094); and CD90(+) in 36.18% of mononuclear cells, 6.01% in skeletal muscle cells, and 48.94% among cocultured cells (P = .0420). The cocultured cells expressed the markers CD73(++), CD90(+++), CD45(-), CD34(+), CD105(-/+), CD106(-/+), M-cadherin(-/+), and Connexin-43(-/+). In conclusion, flow cytometric analysis showed a heterogeneous adherent cell population in this coculture model.

Functional outcome of bone marrow stem cells (CD45(+)/CD34(-)) after cell therapy in acute spinal cord injury: in exercise training and in sedentary rats.

BACKGROUND: Cell therapy and exercise training may be options for spinal cord regeneration. Our objective was to evaluate the functional effects of autologous bone marrow stem cell (CD45(+)/CD34(-)) transplantation in acute spinal cord injury in exercise training and in sedentary rats. MATERIALS AND METHODS: Fifty-five adult male Wistar rats underwent spinal cord contusion by Impactor (NYU). Locomotor rating scale was performed every 48 hours for 48 days. Animals with scores < or = 12 were randomly divided into 4 groups: sedentary without parenchymal cell infusion; sedentary with parenchymal cell infusion; swimming training without parenchymal cell infusion; and swimming training with parenchymal cell infusion. Bone marrow stem cells were isolated by puncture-aspiration of the bone marrow and density gradient (d = 1.077). The animals underwent a 60-minute swimming session 6 times/week supporting an overload of 3% of body weight for 6 consecutive weeks. Comparisons between the groups in relation to differences between the beginning to the end of scores used the nonparametric Bonferroni test and post-hoc Mann-Whitney U test to identify significance. RESULTS: Forty-two rats that obtained scores < or = 12 underwent therapy with 9 animals in each of the 4 groups as completors (n = 36). There was significance (P < or = .008) for sedentary without parenchymal cell infusion vs swimming training with parenchymal cell infusion. CONCLUSION: The combination of bone marrow stem cell therapy (CD45(+)/CD34(-)) and exercise training resulted in significant functional improvement in acute spinal cord injury.