Regenerating Damaged Myocardium: A Review of Stem-Cell Therapies for Heart Failure

The role of cardiac microenvironment in cardiovascular diseases: implications for therapy

Due to aging populations and changes in lifestyle, cardiovascular diseases including cardiomyopathy, hypertension, and atherosclerosis, are the leading causes of death worldwide. The heart is a complicated organ composed of multicellular types, including cardiomyocytes, fibroblasts, endothelial cells, vascular smooth muscle cells, and immune cells. Cellular specialization and complex interplay between different cell types are crucial for the cardiac tissue homeostasis and coordinated function of the heart. Mounting studies have demonstrated that dysfunctional cells and disordered cardiac microenvironment are closely associated with the pathogenesis of various cardiovascular diseases. In this paper, we discuss the composition and the homeostasis of cardiac tissues, and focus on the role of cardiac environment and underlying molecular mechanisms in various cardiovascular diseases. Besides, we elucidate the novel treatment for cardiovascular diseases, including stem cell therapy and targeted therapy. Clarification of these issues may provide novel insights into the prevention and potential targets for cardiovascular diseases.

Alleviation of doxorubicin-induced cardiotoxicity in rat by mesenchymal stem cells and olive leaf extract via MAPK/ TNF-α pathway: Preclinical, experimental and bioinformatics enrichment study

BACKGROUND

Toxic cardiomyopathies were a potentially fatal adverse effect of anthracycline therapy.

AIM

This study was conducted to demonstrate the pathogenetic, morphologic, and toxicologic effects of doxorubicin on the heart and to investigate how the MAPK /TNF-α pathway can be modulated to improve doxorubicin-Induced cardiac lesions using bone marrow-derived mesenchymal stem cells (BM-MSCs) and olive leaf extract (OLE).

METHODS

During the study, 40 adult male rats were used. Ten were used to donate MSCs, and the other 30 were split into 5 equal groups: Group I was the negative control, Group II obtained oral OLE, Group III obtained an intraperitoneal cumulative dose of DOX (12 mg/kg) in 6 equal doses of 2 mg/kg every 48 h for 12 days, Group IV obtained intraperitoneal DOX and oral OLE at the same time, and Group V obtained intraperitoneal DOX and BM-MSCs through the tail vein at the same time for 12 days. Four weeks after their last dose of DOX, the rats were euthanized. By checking the bioinformatic databases, a molecularly targeted path was selected. Then the histological, immunohistochemistry, and gene expression of ERK, JNK, NF-κB, IL-6, and TNF-α were done.

RESULTS

Myocardial immunohistochemistry revealed severe fibrosis, cell degeneration, increased vimentin, and decreased CD-31 expression in the DOX-treated group, along with a marked shift in morphometric measurements, a disordered ultrastructure, and overexpression of inflammatory genes (ERK, NF-κB, IL-6, and TNF-α), oxidative stress markers, and cardiac biomarkers. Both groups IV and V displayed reduced cardiac fibrosis or inflammation, restoration of the microstructure and ultrastructure of the myocardium, downregulation of inflammatory genes, markers of oxidative stress, and cardiac biomarkers, a notable decline in vimentin, and an uptick in CD-31 expression. In contrast to group IV, group V showed a considerable beneficial effect.

CONCLUSION

Both OLE and BM-MSCs showed an ameliorating effect in rat models of DOX-induced cardiotoxicity, with BM-MSCs showing a greater influence than OLE.

Extracellular vesicles in cardiac repair and regeneration: Beyond stem-cell-based approaches

The adult human heart poorly regenerate after injury due to the low self-renewal capability retained by adult cardiomyocytes. In the last two decades, several clinical studies have reported the ability of stem cells to induce cardiac regeneration. However, low cell integration and survival into the tissue has limited stem-cell-based clinical approaches. More recently, the release of paracrine mediators including extracellular vesicles (EV) has been recognized as the most relevant mechanism driving benefits upon cell-based therapy. In particular, EV have emerged as key mediators of cardiac repair after damage, in terms of reduction of apoptosis, resolution of inflammation and new blood vessel formation. Herein, mechanisms involved in cardiac damage and regeneration, and current applications of EV and their small non-coding RNAs (miRNAs) in regenerative medicine are discussed.

Restenosis after Coronary Stent Implantation: Cellular Mechanisms and Potential of Endothelial Progenitor Cells (A Short Guide for the Interventional Cardiologist)

Coronary stents are among the most common therapies worldwide. Despite significant improvements in the biocompatibility of these devices throughout the last decades, they are prone, in as many as 10–20% of cases, to short- or long-term failure. In-stent restenosis is a multifactorial process with a complex and incompletely understood pathophysiology in which inflammatory reactions are of central importance. This review provides a short overview for the clinician on the cellular types responsible for restenosis with a focus on the role of endothelial progenitor cells. The mechanisms of restenosis are described, along with the cell-based attempts made to prevent it. While the focus of this review is principally clinical, experimental evidence provides some insight into the potential implications for prevention and therapy of coronary stent restenosis.