Skeletal Myoblast Cell Sheet Implantation Ameliorates Both Systolic and Diastolic Cardiac Performance in Canine Dilated Cardiomyopathy Model

Autologous skeletal myoblast patch implantation prevents the deterioration of myocardial ischemia and right heart dysfunction in a pressure-overloaded right heart porcine model

Right ventricular dysfunction is a predictor for worse outcomes in patients with congenital heart disease. Myocardial ischemia is primarily associated with right ventricular dysfunction in patients with congenital heart disease and may be a therapeutic target for right ventricular dysfunction. Previously, autologous skeletal myoblast patch therapy showed an angiogenic effect for left ventricular dysfunction through cytokine paracrine effects; however, its efficacy in right ventricular dysfunction has not been evaluated. Thus, this study aimed to evaluate the angiogenic effect of autologous skeletal myoblast patch therapy and amelioration of metabolic and functional dysfunction, in a pressure-overloaded right heart porcine model. Pulmonary artery stenosis was induced by a vascular occluder in minipigs; after two months, autologous skeletal myoblast patch implantation on the right ventricular free wall was performed (n = 6). The control minipigs underwent a sham operation (n = 6). The autologous skeletal myoblast patch therapy alleviated right ventricular dilatation and ameliorated right ventricular systolic and diastolic dysfunction. 11C-acetate kinetic analysis using positron emission tomography showed improvement in myocardial oxidative metabolism and myocardial flow reserve after cell patch implantation. On histopathology, a higher capillary density and vascular maturity with reduction of myocardial ischemia were observed after patch implantation. Furthermore, analysis of mRNA expression revealed that the angiogenic markers were upregulated, and ischemic markers were downregulated after patch implantation. Thus, autologous skeletal myoblast patch therapy ameliorated metabolic and functional dysfunction in a pressure-overloaded right heart porcine model, by alleviating myocardial ischemia through angiogenesis.

Arrhythmogenic risks of stem cell replacement therapy for cardiovascular diseases

Ischemic heart disease and congestive heart failure are major contributors to high morbidity and mortality. Approximately 1.5 million cases of myocardial infarction occur annually in the United States; the yearly incidence rate is approximately 600 cases per 100,000 people. Although significant progress to improve the survival rate has been made by medications and implantable medical devices, damaged cardiomyocytes are unable to be recovered by current treatment strategies. After almost two decades of research, stem cell therapy has become a very promising approach to generate new cardiomyocytes and enhance the function of the heart. Along with clinical trials with stem cells conducted in cardiac regeneration, concerns regarding safety and potential risks have emerged. One of the contentious issues is the electrical dysfunctions of cardiomyocytes and cardiac arrhythmia after stem cell therapy. In this review, we focus on the cell sources currently used for stem cell therapy and discuss related arrhythmogenic risk.

Clinical, Pathological, and Ethical Considerations for the Conduct of Clinical Trials in Dogs with Naturally Occurring Cancer: A Comparative Approach to Accelerate Translational Drug Development

The role of comparative oncology in translational research is receiving increasing attention from drug developers and the greater biomedical research community. Pet dogs with spontaneous cancer are important and underutilized translational models, owing to dogs' large size and relative outbreeding, combined with their high incidence of certain tumor histotypes with significant biological, genetic, and histological similarities to their human tumor counterparts. Dogs with spontaneous tumors naturally develop therapy resistance and spontaneous metastasis, all in the context of an intact immune system. These fundamental features of cancer biology are often lacking in induced or genetically engineered preclinical tumor models and likely contribute to their poor predictive value and the associated overall high failure rate in oncology drug development. Thus, the conduct of clinical trials in pet dogs with naturally occurring cancer represents a viable surrogate and valuable intermediary step that should be increasingly incorporated into the cancer drug discovery and development pipeline. The development of molecular-targeted therapies has resulted in an expanded role of the pathologist in human oncology trials, and similarly the expertise of veterinary pathologists will be increasingly valuable to all phases of comparative oncology trial design and conduct. In this review, we provide a framework of clinical, ethical, and pathology-focused considerations for the increasing integration of translational research investigations in dogs with spontaneous cancer as a means to accelerate clinical cancer discovery and drug development.

Intracoronary Gene Delivery of the Cytoprotective Factor Vascular Endothelial Growth Factor-B167 in Canine Patients with Dilated Cardiomyopathy: A Short-Term Feasibility Study

Dilated cardiomyopathy (DCM) is a myocardial disease of dogs and humans characterized by progressive ventricular dilation and depressed contractility and it is a frequent cause of heart failure. Conventional pharmacological therapy cannot reverse the progression of the disease and, in humans, cardiac transplantation remains the only option during the final stages of heart failure. Cytoprotective gene therapy with vascular endothelial growth factor-B₁₆₇ (VEGF-B₁₆₇) has proved an effective alternative therapy, halting the progression of the disease in experimental studies on dogs. The aim of this work was to test the tolerability and feasibility of intracoronary administration, under fluoroscopic guidance, of VEGF-B₁₆₇ carried by adeno-associated viral vectors in canine DCM patients. Ten patients underwent the gene delivery procedure. The intraoperative phase was well tolerated by all dogs. Clinical and echocardiographic assessments at 7- and 30-days post-procedure showed stable conditions compared to the pre-procedure phase. The results of this work indicate that intracoronary VEGF-B₁₆₇ gene delivery is feasible and tolerated in dogs with DCM. Further monitoring/investigations are ongoing to evaluate the effects of this therapy on disease progression.

Long-term outcome of a dilated cardiomyopathy patient after mitral valve surgery combined with tissue-engineered myoblast sheets-report of a case

BACKGROUND

Dilated cardiomyopathy (DCM) is a life-threatening heart muscle disease characterized by progressive heart failure, which often requires left ventricular assist device (LVAD) implantation or heart transplantation (HTx). A tissue engineering strategy using cell sheets for end-stage heart failure has emerged in recent years.

CASE PRESENTATION

Here, we describe a 50-year-old DCM patient with severe symptoms of heart failure with severe mitral regurgitation (MR) who was not a candidate for LVAD or HTx. The patient underwent mitral valve replacement followed by the transplantation of autologous myoblast sheets.

CONCLUSION

The patient's clinical symptoms improved with a preservation of cardiac performance, and he has survived for over 6 years since the combined surgery. This combined method was feasible and appeared to be effective, and thus represents a promising strategy for treating severe heart failure in end-stage DCM and as an alternative treatment for selected patients who are not candidates for LVAD or HTx.

Bone marrow-derived mononuclear cell therapy for nonischaemic dilated cardiomyopathy-A meta-analysis

OBJECTIVE

The therapeutic effects of bone marrow-derived mononuclear cells (BMMNCs) transplantation in patients with nonischaemic dilated cardiomyopathy (DCM) are still under debate. Current randomized controlled trials (RCTs) reported conflicting results. The aim of this study was to assess the effects of BMMNCs transplantation on left ventricular ejection fraction (LVEF) in patients with nonischaemic DCM.

METHODS

A comprehensive search of PubMed, EMBASE and Cochrane Controlled Trials Register was performed. We included RCTs reporting data on LVEF in patients with nonischaemic DCM after BMMNCs transplantation.

RESULTS

Seven RCTs including 463 patients were included. BMMNCs transplantation significantly improved LVEF by 3.79% (95% CI: 0.56%-7.03%; P = .007) and LVESV by -24.36 mL (95% CI: -46.36 to -2.36 mL; P = .03), while had no impact on the risk of all-cause death (OR 0.92; 95% CI: 0.41 to 2.08%; P = .84). Subgroup analysis demonstrated a more significant improvement of LVEF in patients with longer follow-up (~15 months to 5 years) than shorter ones (12 months). Moreover, using bone marrow mononuclear cells was more effective than using G-CSF-stimulated bone marrow/peripheral blood stem cells in the improvement of LVEF in patients with nonischaemic DCM.

CONCLUSIONS

Bone marrow-derived mononuclear cells transplantation is associated with a moderate, but significant, improvement in LVEF in patients with nonischaemic DCM. This meta-analysis supports further RCT conductions using BMMNCs transplantation with larger patient's population and longer term follow-up.

Myocardial Tissue Engineering for Regenerative Applications

PURPOSE OF REVIEW

This review provides an overview of the current state of tissue-engineered heart repair with a special focus on the anticipated modes of action of tissue-engineered therapy candidates and particular implications as to transplant immunology.

RECENT FINDINGS

Myocardial tissue engineering technologies have made tremendous advances in recent years. Numerous different strategies are under investigation and have reached different stages on their way to clinical translation. Studies in animal models demonstrated that heart repair requires either remuscularization by delivery of bona fide cardiomyocytes or paracrine support for the activation of endogenous repair mechanisms. Tissue engineering approaches result in enhanced cardiomyocyte retention and sustained remuscularization, but may also be explored for targeted paracrine or mechanical support. Some of the more advanced tissue engineering approaches are already tested clinically; others are at late stages of pre-clinical development. Process optimization towards cGMP compatibility and clinical scalability of contractile engineered human myocardium is an essential step towards clinical translation. Long-term allograft retention can be achieved under immune suppression. HLA matching may be an option to enhance graft retention and reduce the need for comprehensive immune suppression. Tissue-engineered heart repair is entering the clinical stage of the translational pipeline. Like in any effective therapy, side effects must be anticipated and carefully controlled. Allograft implantation under immune suppression is the most likely clinical scenario. Strategies to overcome transplant rejection are evolving and may further boost the clinical acceptance of tissue-engineered heart repair.

Treatment of Vesicovaginal Fistulas With Autologous Cell Injections—A Randomized Study in an Animal Model

Purpose:

Materials and Methods:

Results:

Conclusion: