Allogenic Skeletal Myoblast Transplantation in Acute Myocardial Infarction Model Rats

Intervention effects of traditional Chinese medicine on stem cell therapy of myocardial infarction

Cardiovascular diseases are the leading cause of global mortality, in which myocardial infarction accounts for 46% of total deaths. Although good progress has been achieved in medication and interventional techniques, a proven method to repair the damaged myocardium has not yet been determined. Stem cell therapy for damaged myocardial repair has evolved into a promising treatment for ischemic heart disease. However, low retention and poor survival of the injected stem cells are the major obstacles to achieving the intended therapeutic effects. Chinese botanical and other natural drug substances are a rich source of effective treatment for various diseases. As such, numerous studies have revealed the role of Chinese medicine in stem cell therapy for myocardial infarction treatment, including promoting proliferation, survival, migration, angiogenesis, and differentiation of stem cells. Here, we discuss the potential and limitations of stem cell therapy, as well as the regulatory mechanism of Chinese medicines underlying stem cell therapy. We focus on the evidence from pre-clinical trials and clinical practices, and based on traditional Chinese medicine theories, we further summarize the mechanisms of Chinese medicine treatment in stem cell therapy by the commonly used prescriptions. Despite the pre-clinical evidence showing that traditional Chinese medicine is helpful in stem cell therapy, there are still some limitations of traditional Chinese medicine therapy. We also systematically assess the detailed experimental design and reliability of included pharmacological research in our review. Strictly controlled animal models with multi-perspective pharmacokinetic profiles and high-grade clinical evidence with multi-disciplinary efforts are highly demanded in the future.

Cell Spray Transplantation of Adipose-derived Mesenchymal Stem Cell Recovers Ischemic Cardiomyopathy in a Porcine Model

BACKGROUND

Allogeneic adipose-derived mesenchymal stem cells (ADSC) are promising cell sources for cell therapy to treat ischemic cardiomyopathy (ICM). We hypothesized that ADSC transplantation via the new cell spray method may be a feasible, safe, and effective treatment for ICM.

METHODS

Human ADSCs were acquired from white adipose tissue. Porcine ICM models were established by constriction of the left anterior descending coronary artery. Adipose-derived mesenchymal stem cells were spread over the surface of the heart via cell spray in fibrinogen and thrombin solutions. The cardiac function was compared with that of the control group.

RESULTS

Adipose-derived mesenchymal stem cells were successfully transplanted forming a graft-like gel film covering the infarct myocardium. Premature ventricular contractions were rarely detected in the first 3 days after transplantation. Echocardiography and magnetic resonance imaging revealed improved cardiac performance of the ADSC group at 4 and 8 weeks after transplantation. Systolic and diastolic parameters were significantly greater in the ADSC group at 8 weeks after transplantation. Histological examination showed significantly attenuated left ventricular remodeling and a greater vascular density in the infarct border area in the ADSC group. Moreover, the coronary flow reserve was maintained, and expression levels of angiogenesis-related factors in the infarct border and remote areas were significantly increased.

CONCLUSIONS

Spray method implantation of allogenic ADSCs can improve recovery of cardiac function in a porcine infarction model. This new allogenic cell delivery system may help to resolve current limitations of invasiveness and cost in stem cell therapy.

Systemic Administration of Granulocyte Colony-Stimulating Factor for Osteochondral Defect Repair in a Rat Experimental Model

OBJECTIVE

The objective of this study was to assess the effect of granulocyte colony-stimulating factor (G-CSF) on osteochondral defect repair in the rat knee.

DESIGN

Twenty-six 12-week-old male Lewis rats were randomly divided into 2 groups. From day 0 to day 4, the G-CSF group received glycosylated G-CSF, and the control group received phosphate-buffered saline. A 1.5-mm diameter and 1.0-mm deep osteochondral defect was introduced in the patellar groove of the bilateral femur in all rats on day 4. The peripheral blood nucleated cells were counted for 14 days from the first day of injection, the appearance of the cartilage repair was observed histologically and macroscopically for 2, 4, 8, 12, and 24 weeks after surgery.

RESULTS

The number of peripheral blood leukocytes increased 3 days and returned to normal levels 7 days after the first injection. Compared with the control group, the G-CSF group had more fibrous and/or bony tissue at earlier points in time. The tissue repair rate, which is defined as the percentage of repaired osteochondral defects, was significantly higher in the G-CSF group 4 weeks after surgery. However, there were no significant differences in the cartilage repair rate and the modified Wakitani score between the 2 groups at each time point.

CONCLUSIONS

The defect filling was significantly better in the G-CSF group in the early phases. Our findings suggest that G-CSF may promote the repair of osteochondral defects by mediating an increase in the number of peripheral blood nucleated cells.

VEGF165 attenuates the Th17/Treg imbalance that exists when transplanting allogeneic skeletal myoblasts to treat acute myocardial infarction

OBJECTIVES

To investigate whether Th17/Treg imbalance exists, and whether VEGF(165) attenuates the imbalance in allogeneic skeletal myoblast transplantation (allo-SMT) for acute myocardial infarction (AMI).

METHODS

On days 1, 2, 4, and 7 after allo-SMT, the percentages and ratios of Th17 and Treg cells were analyzed by flow cytometry in three groups-the AMI group, the AMI-S group (allo-SMT) and the AMI-V group (with VEGF(165) treatment). Subsequently, related proinflammatory and regulatory cytokines and key transcription factors, ROR-γt mRNA and Foxp3 mRNA expression, were examined by Bio-plex and real-time polymerase chain reaction, respectively.

RESULTS

On days 1, 2, 4, and 7, the percentage of Tregs, related cytokine concentrations and transcript factor Foxp3 mRNA in the AMI-S group were lower than those in the AMI group, while those in the AMI-V group were higher than those in the AMI group. However, the percentage of Th17 cells, related cytokine concentrations and ROR-γt mRNA in the AMI-S group were higher than those in the AMI group; those in the AMI-V group were lower than those in the AMI group. Compared with the AMI group, the ratios of Th17/Treg cells significantly increased in the AMI-S group and decreased in the AMI-V group.

CONCLUSIONS

Th17/Treg imbalance participated in the formation and development of the inflammatory and immune response after allo-SMT. However, transfected VEGF(165) was able to relieve the severity of the Th17/Treg imbalance.

Preconditioning approach in stem cell therapy for the treatment of infarcted heart

Nearly two decades of research in regenerative medicine have been focused on the development of stem cells as a therapeutic option for treatment of the ischemic heart. Given the ability of stem cells to regenerate the damaged tissue, stem-cell-based therapy is an ideal approach for cardiovascular disorders. Preclinical studies in experimental animal models and clinical trials to determine the safety and efficacy of stem cell therapy have produced encouraging results that promise angiomyogenic repair of the ischemically damaged heart. Despite these promising results, stem cell therapy is still confronted with issues ranging from uncertainty about the as-yet-undetermined "ideal" donor cell type to the nonoptimized cell delivery strategies to harness optimal clinical benefits. Moreover, these lacunae have significantly hampered the progress of the heart cell therapy approach from bench to bedside for routine clinical applications. Massive death of donor cells in the infarcted myocardium during acute phase postengraftment is one of the areas of prime concern, which immensely lowers the efficacy of the procedure. An overview of the published data relevant to stem cell therapy is provided here and the various strategies that have been adopted to develop and optimize the protocols to enhance donor stem cell survival posttransplantation are discussed, with special focus on the preconditioning approach.