Skeletal myoblast transplant in heart failure

Stem cell-based therapies for heart failure management: a narrative review of current evidence and future perspectives

Heart failure (HF) is a prevalent and debilitating global cardiovascular condition affecting around 64 million individuals, placing significant strain on healthcare systems and diminishing patients' quality of life. The escalating prevalence of HF underscores the urgent need for innovative therapeutic approaches that target the root causes and aim to restore normal cardiac function. Stem cell-based therapies have emerged as promising candidates, representing a fundamental departure from conventional treatments focused primarily on symptom management. This review explores the evolving landscape of stem cell-based therapies for HF management. It delves into the mechanisms of action, clinical evidence from both positive and negative outcomes, ethical considerations, and regulatory challenges. Key findings include the potential for improved cardiac function, enhanced quality of life, and long-term benefits associated with stem cell therapies. However, adverse events and patient vulnerabilities necessitate stringent safety assessments. Future directions in stem cell-based HF therapies include enhancing efficacy and safety through optimized stem cell types, delivery techniques, dosing strategies, and long-term safety assessments. Personalized medicine, combining therapies, addressing ethical and regulatory challenges, and expanding access while reducing costs are crucial aspects of the evolving landscape.

Effect of dielectric interface on charge aggregation in the voltage-gated K(+) ion channel

Background:

There is experimental evidence of many cases of stable macromolecular conformations with charged amino-acids facing lipid, an arrangement thought to be energetically unfavourable.

Methods and Objectives:

Employing classical electrostatics, we show that, this is not necessarily the case and studied the physical basis of the specific role of proximity of charges to the dielectric interface between two different environments. We illustrate how self and induced energies due to the dielectric medium polarization, on either side of the interface, contribute differentially to the stability of a pair of charges and hence the mutual conformation of the S3b-S4 α-helix pair of the voltage-gated K⁺ channel.

Results and Conclusion:

We show that (1) a pair of opposite charges on either side of lipid-protein interface confers significant stability; (2) hydrophobic media has an important role in holding together two similar repelling charges; (3) dielectric interface has stabilizing effect on a pair of charges, when an ion is closer to its interface than its neighboring charge; (4) in spite of the presence of dielectric interface, there is a nonexistence of any dielectric effect, when an ion is equidistant from its image and neighboring charge. We also demonstrate that, variation in dielectric media of the surrounding environment confers new mutual conformations to S3b-S4 α-helices of voltage sensor domain at zero potential, especially lipid environment on the helix side, which improved stability to the configuration by lowering the potential energy. Our results provide an answer to the long standing question of why charges face hydrophobic lipid membranes in the stable conformation of a protein.

Concise review: skeletal muscle stem cells and cardiac lineage: potential for heart repair

Valuable and ample resources have been spent over the last two decades in pursuit of interventional strategies to treat the unmet demand of heart failure patients to restore myocardial structure and function. At present, it is clear that full restoration of myocardial structure and function is outside our reach from both clinical and basic research studies, but it may be achievable with a combination of ongoing research, creativity, and perseverance. Since the 1990s, skeletal myoblasts have been extensively investigated for cardiac cell therapy of congestive heart failure. Whereas the Myoblast Autologous Grafting in Ischemic Cardiomyopathy (MAGIC) trial revealed that transplanted skeletal myoblasts did not integrate into the host myocardium and also did not transdifferentiate into cardiomyocytes despite some beneficial effects on recipient myocardial function, recent studies suggest that skeletal muscle-derived stem cells have the ability to adopt a cardiomyocyte phenotype in vitro and in vivo. This brief review endeavors to summarize the importance of skeletal muscle stem cells and how they can play a key role to surpass current results in the future and enhance the efficacious implementation of regenerative cell therapy for heart failure.

Transplantation of nanoparticle transfected skeletal myoblasts overexpressing vascular endothelial growth factor-165 for cardiac repair

BACKGROUND

We investigated the feasibility and efficacy of polyethylenimine (PEI) based human vascular endothelial growth factor-165 (hVEGF165) gene transfer into human skeletal myoblasts (HSM) for cell based delivery to the infarcted myocardium.

METHODS AND RESULTS

Based on optimized transfection procedure using enhanced green fluorescent protein (pEGFP), HSM were transfected with plasmid-hVEGF165 (phVEGF165) carried by PEI (PEI-phVEGF165) nanoparticles. The transfected HSM were characterized for transfection and expression of hVEGF165 in vitro and transplanted into rat heart model of acute myocardial infarction (AMI): group-1=DMEM injection, group-2= HSM transplantation, group-3= PEI-phVEGF165-transfected HSM (PEI-phVEGF165 myoblast) transplantation. A total of 48 rats received cyclosporine injection from 3 days before and until 4 weeks after cell transplantation. Echocardiography was performed to assess the heart function. Animals were sacrificed for molecular and histological studies on the heart tissue at 4 weeks after treatment. Based on optimized transfection conditions, transfected HSM expressed hVEGF165 for 18 days with >90% cell viability in vitro. Apoptotic index was reduced in group-2 and group-3 as compared with group-1. Blood vessel density (x400) by immunostaining for PECAM-1 in group-3 was significantly higher (P=0.043 for both) as compared with group-1 and group-2 at 4 weeks. Regional blood flow (ml/min/g) in the left ventricular anterior wall was higher in group-3 (P=0.043 for both) as compared with group-1 and group-2. Improved ejection fraction was achieved in group-3 (58.44+/-4.92%) as compared with group-1 (P=0.004).

CONCLUSION

PEI nanoparticle mediated hVEGF165 gene transfer into HSM is feasible and safe. It may serve as a novel and efficient alternative for angiomyogenesis in cardiac repair.

A Canadian perception of the nursing practice, research, and theoretical implications associated with autologous cell transplantation

Heart failure is a progressive disorder. An estimated 400,000 Canadians are diagnosed annually with heart failure, and a quarter experience severe heart failure that is unresponsive to medical therapy. Autologous cell transplantation has been proposed as a new approach for cardiac repair and holds enormous potential for the regeneration of injured myocardium cells. Currently, autologous cell transplantation is under investigation in Canada. Its use as a treatment alternative for heart failure patients has been established over the past 5 years across Europe and the United States. This article will present a Canadian perception of the nursing practice, research, and theoretical implications associated with this new and innovative therapy.

Angiopoietin-1 for myocardial angiogenesis: A comparison between delivery strategies

We compare the effectiveness of direct adenoviral angiopoietin-1 (Ad-Ang-1) injection with transplantation of skeletal myoblasts (SkMs) over-expressing angiopoietin-1 (Ang-1) for angiogenic response and improvement of heart function in an experimental porcine model of myocardial infarction (MI).

METHODS

Ad-Ang-1 was used for intramyocardial injection or transduction of SkMs. Three weeks after coronary artery ligation in 32 female pigs, animals were grouped to receive multiple intramyocardial injections of DMEM without cells (group-1; n=7), or containing 3 x 10(8)Lac-z labelled SkMs transduced with Ad-Null vector carrying no gene (group-2; n=7), or 1 x 10(10) PFU Ad-Ang-1 (group-3; n=9), or 3 x 10(8)Lac-z labelled SkMs transduced with Ad-Ang-1 (group-4; n=9). The animals were immunosuppressed for 6-weeks. After euthanasia, their heart tissue was processed for histological studies.

RESULTS

Extensive survival of Lac-z positive SkMs was observed in and around the infarct 6 and 12-weeks after transplantation. Fluorescent immunostaining for vWF-VIII at 6-weeks revealed increased blood vessel density (x100) in group-4 (p<0.05) as compared with other groups. Regional blood flow (ml/g/min) in the peri-infarct area was improved in group-4 (2.7; p<0.05) as compared with group-1 (1.2+/-0.1), group-2 (1.1+/-0.4) and group-3 (1.7+/-0.1) at 6-weeks. Similarly, ejection fraction was significantly higher in group-4 (49.2+/-5.9%, p=0.03) as compared with group-1 (36.8+/-3%) at 6 weeks.

CONCLUSION

SkMs mediated Ang-1 delivery is associated with improved angiogenic response, regional myocardial perfusion and heart function as compared with direct Ad-Ang-1 administration.

Repeated Implantation is a More Effective Cell Delivery Method in Skeletal Myoblast Transplantation for Rat Myocardial Infarction

BACKGROUND

Several clinical trials are underway to determine whether autologous skeletal myoblast transplantation is an effective and safe therapeutic strategy for severe heart failure due to myocardial infarction (MI). It remains unclear whether repeated skeletal myoblast implantation is a feasible and effective cell delivery method for the infarcted myocardium.

METHODS AND RESULTS

Four weeks after a coronary ligation, male syngeneic Lewis rats were assigned to 3 treatment groups: 3 episodes of skeletal myoblasts (6x10(6)) transplantation (group I), a bolus transplantation of myoblasts (18x10(6)) (group II), or culture medium injection (group III). Eight weeks after the first treatment, echocardiography, cardiac catheterization and histological examination were performed to compare the therapeutic effects on left ventricular (LV) systolic and diastolic functions, and the engrafted myoblast volume. Repeated myoblast implantation significantly improved LV function and resulted in significantly larger engrafted volume and LV contractility compared with a bolus transplantation with the same number of myoblasts.

CONCLUSIONS

Repeated skeletal myoblast transplantation is a safe and effective therapeutic strategy for the infarcted myocardium.

Cellular cardiomyoplasty for myocardial regeneration

The evolving challenge of managing patients with congestive heart failure is the need to develop new therapeutic strategies. The cellular, molecular, and genetic approaches investigated aim to reinforce the weak, failing heart muscle while restoring its functional potential. This approach is principally cellular therapy (i.e. cellular cardiomyoplasty), the preferred therapeutic choice because of its clinical applicability and regenerative capacity. Different stem cells: bone marrow cells, skeletal and smooth muscle cells, vascular endothelial cells, mesothelial cells, adipose tissue stroma cells, dental stem cells, and embryonic and fetal cells, have been proposed for regenerative medicine and biology. Stem cell mobilization with G-CSF cytokine was also proposed as a single therapy for myocardial infarction. We investigated the association of cell therapy with electrostimulation (dynamic cellular cardiomyoplasty), the use of autologous human serum for cell cultures, and a new catheter for simultaneous infarct detection and cell delivery. Our team conducted cell-based myogenic and angiogenic clinical trials for chronic ischemic heart disease. Cellular cardiomyoplasty constitutes a new approach for myocardial regeneration; the ultimate goal is to avoid the progression of ventricular remodeling and heart failure for patients presenting with ischemic and non-ischemic cardiomyopathies.

Effectiveness of transient immunosuppression using cyclosporine for xenomyoblast transplantation for cardiac repair

We studied the survival of human myoblast for cellular myocardial reconstruction in a porcine model of chronic myocardial ischemia with immune tolerance using transient immunosuppression. A porcine model of chronic cardiac ischemia was created in 10 pigs (DMEM medium-injected n = 4; myoblast transplanted n = 6) by clamping ameroid ring around left circumflex coronary artery. Three weeks later, 3 x 10(8) human myoblasts carrying lac-z reporter gene were transplanted in multiple sites (0.25 mL each) into the left ventricular wall. Immunosuppression was achieved with 5 mg/kg cyclosporine for 6 weeks after cell transplantation. After animals were euthanized between 6 and 30 weeks after cell transplantation; the heart was removed for histological studies. Discontinuation of immunosuppression after 6 weeks of cell transplantation did not result in donor cell rejection. The lac-z-positive donor cells were detected in porcine host cardiac tissue for up to 30 weeks posttransplantation, expressing human skeletal myosin heavy chain. The results highlight the effectiveness of transient immunosuppression for myoblast transplantation for cardiac repair.