Research Progress of Electrical Stimulation in Ischemic Heart Disease

Nanoscale piezoelectric patches preserve electrical integrity of infarcted hearts

Ischemic heart disease is the leading cause of death worldwide. Several approaches have been explored to restore cardiac function, however few investigated new strategies to improve electrical functional recovery. Herein, we have investigated the impact of piezoelectric patches (Piezo patches), capable of generating electric charges upon mechanical deformation, on rat cardiac slices, healthy and ischemic hearts (ex vivo), on infarcted mice (in vivo) and on healthy and infarcted pigs (in vivo). Piezo patches did not preclude cardiac slice contractility, while compared with electrically inert control patches. In addition, Piezo patches showed an adequate safety profile in a working heart model as no electrophysiologic alterations were detected in healthy hearts. Epicardial implantation of Piezo patches in acutely infarcted mice hearts significantly improved myocardial electrical integrity without disturbing systolic function. Moreover, Piezo patches partially prevented ischemia-related adverse cardiac remodeling, reducing left ventricular chamber dilatation and compensatory hypertrophy. Coherently, Piezo patch-implanted hearts revealed downregulation of genes associated with extracellular matrix remodeling. Importantly, in vivo implantation of Piezo patches in porcine hearts revealed to be electrically safe as no major effects in its electrophysiology were detected. Overall, the results presented here endorse Piezo patches as a promising therapeutic strategy to improve post-myocardial infarction structural and electrical remodeling.

Rebuilding the myocardial microenvironment to enhance mesenchymal stem cells-mediated regeneration in ischemic heart disease

Mesenchymal stem cells (MSCs) are naturally-derived regenerative materials that exhibit significant potential in regenerative medicine. Previous studies have demonstrated that MSCs-based therapy can improve heart function in ischemia-injured hearts, offering an exciting therapeutic intervention for myocardial ischemic infarction, a leading cause of worldwide mortality and disability. However, the efficacy of MSCs-based therapies is significantly disturbed by the myocardial microenvironment, which undergoes substantial changes following ischemic injury. After the ischemic injury, blood vessels become obstructed and damaged, and cardiomyocytes experience ischemic conditions. This activates the hypoxia-induced factor 1 (HIF-1) pathway, leading to the rapid production of several cytokines and chemokines, including vascular endothelial growth factor (VEGF) and stromal-derived factor 1 (SDF-1), which are crucial for angiogenesis, cell migration, and tissue repair, but it is not sustainable. MSCs respond to these cytokines and chemokines by homing to the injured site and participating in myocardial regeneration. However, the deteriorated microenvironment in the injured myocardium poses challenges for cell survival, interacting with MSCs, and constraining their homing, retention, and migration capabilities, thereby limiting their regenerative potential. This review discusses how the deteriorated microenvironment negatively affects the ability of MSCs to promote myocardial regeneration. Recent studies have shown that optimizing the microenvironment through the promotion of angiogenesis can significantly enhance the efficacy of MSCs in treating myocardial infarction. This approach harnesses the full therapeutic potential of MSCs-based therapies for ischemic heart disease.

Electrical stimulation promoting the angiogenesis in diabetic rat perforator flap through attenuating oxidative stress-mediated inflammation and apoptosis

Background

Skin flap transplantation is one of the effective methods to treat the diabetes-related foot ulceration, but the intrinsic damage to vessels in diabetes mellitus (DM) leads to the necrosis of skin flaps. Therefore, the discovery of a non-invasive and effective approach for promoting the survival of flaps is of the utmost importance. Electrical stimulation (ES) promotes angiogenesis and increases the proliferation, migration, and elongation of endothelial cells, thus being a potential effective method to improve flap survival.

Objective

The purpose of this study was to elucidate the mechanism used by ES to effectively restore the impaired function of endothelial cells caused by diabetes.

Methods

A total of 79 adult male Sprague-Dawley rats were used in this study. Gene and protein expression was assessed by PCR and western blotting, respectively. Immunohistochemistry and hematoxylin-eosin staining were performed to evaluate the morphology and density of the microvessels in the flap.

Results

The optimal duration for preconditioning the flap with ES was 7 days. The flap survival area percentage and microvessels density in the DMES group were markedly increased compared to the DM group. VEGF, MMP2, and MMP9 protein expression was significantly upregulated. ROS intensity was significantly decreased and GSH concentration was increased. The expression of IL-1β, MCP‑1, cleaved caspase-3, and Bax were downregulated in the DMES group, while TGF-β expression was upregulated.

Conclusions

ES improves the angiogenesis in diabetic ischemic skin flaps by attenuating oxidative stress-mediated inflammation and apoptosis, eventually increasing their viability.