Biological and Pro-Angiogenic Properties of Genetically Modified Human Primary Myoblasts Overexpressing Placental Growth Factor in In Vitro and In Vivo Studies

Molecular Imaging of Human Skeletal Myoblasts (huSKM) in Mouse Post-Infarction Myocardium

Current treatment protocols for myocardial infarction improve the outcome of disease to some extent but do not provide the clue for full regeneration of the heart tissues. An increasing body of evidence has shown that transplantation of cells may lead to some organ recovery. However, the optimal stem cell population has not been yet identified. We would like to propose a novel pro-regenerative treatment for post-infarction heart based on the combination of human skeletal myoblasts (huSkM) and mesenchymal stem cells (MSCs). huSkM native or overexpressing gene coding for Cx43 (huSKMCx43) alone or combined with MSCs were delivered in four cellular therapeutic variants into the healthy and post-infarction heart of mice while using molecular reporter probes. Single-Photon Emission Computed Tomography/Computed Tomography (SPECT/CT) performed right after cell delivery and 24 h later revealed a trend towards an increase in the isotopic uptake in the post-infarction group of animals treated by a combination of huSkMCx43 with MSC. Bioluminescent imaging (BLI) showed the highest increase in firefly luciferase (fluc) signal intensity in post-infarction heart treated with combination of huSkM and MSCs vs. huSkM alone (p < 0.0001). In healthy myocardium, however, nanoluciferase signal (nanoluc) intensity varied markedly between animals treated with stem cell populations either alone or in combinations with the tendency to be simply decreased. Therefore, our observations seem to show that MSCs supported viability, engraftment, and even proliferation of huSkM in the post-infarction heart.

Recent Approaches for Angiogenesis in Search of Successful Tissue Engineering and Regeneration

Angiogenesis plays a central role in human physiology from reproduction and fetal development to wound healing and tissue repair/regeneration. Clinically relevant therapies are needed for promoting angiogenesis in order to supply oxygen and nutrients after transplantation, thus relieving the symptoms of ischemia. Increase in angiogenesis can lead to the restoration of damaged tissues, thereby leading the way for successful tissue regeneration. Tissue regeneration is a broad field that has shown the convergence of various interdisciplinary fields, wherein living cells in conjugation with biomaterials have been tried and tested on to the human body. Although there is a prevalence of various approaches that hypothesize enhanced tissue regeneration via angiogenesis, none of them have been successful in gaining clinical relevance. Hence, the current review summarizes the recent cell-based and cell free (exosomes, extracellular vesicles, micro-RNAs) therapies, gene and biomaterial-based approaches that have been used for angiogenesis-mediated tissue regeneration and have been applied in treating disease models like ischemic heart, brain stroke, bone defects and corneal defects. This review also puts forward a concise report of the pre-clinical and clinical studies that have been performed so far; thereby presenting the credible impact of the development of biomaterials and their 3D concepts in the field of tissue engineering and regeneration, which would lead to the probable ways for heralding the successful future of angiogenesis-mediated approaches in the greater perspective of tissue engineering and regenerative medicine.

Transient and Stable Overexpression of Extracellular Superoxide Dismutase Is Positively Associated with the Myogenic Function of Human Skeletal Muscle-Derived Stem/Progenitor Cells

In the present study, the genetic modification of human skeletal muscle-derived stem/progenitor cells (SkMDS/PCs) was investigated to identify the optimal protocol for myogenic cell preparation for use in post-infarction heart therapy. We used two types of modifications: GFP-transfection (using electroporation) and SOD3 transduction (using a lentiviral vector). SkMDS/PCs were cultured under different in vitro conditions, including standard (21% oxygen) and hypoxic (3% oxygen), the latter of which corresponded to the prevailing conditions in the post-infarction heart. Transfection/transduction efficacy, skeletal myogenic cell marker expression (CD56), cellular senescence, and apoptosis, as well as the expression of antioxidant (SOD1, SOD2, and SOD3), anti-aging (SIRT1 and FOXO), anti-apoptotic (BCL2), and myogenic (MyoD and MyoG) genes, were evaluated. The percentage of GFP-positive SkMDS/PCs was determined as an indicator of the efficacy of transfection, which reached 55%, while transduction showed better efficiency, reaching approximately 85% as estimated by fluorescence microscopy. The CD56-positive SkMDS/PCs were present in approximately 77% of the tested cells after transient transfection and approximately 96% after transduction. Under standard in vitro culture conditions, the ability of the differentiated, transfected SkMDS/PCs to form myotubes was greater than that of the wild type (WT) cell population (p < 0.001), while the cells transduced with the SOD3 gene exhibited an increase in cell fusion under both standard (p < 0.05) and hypoxic conditions (p < 0.001). In transduced SkMDS/PCs, we observed a positive influence of SOD3 overexpression on cell ageing and apoptosis. We observed an increase in the percentage of young cells under standard (p < 0.05) and hypoxic (p < 0.001) in vitro culture conditions, with a notable decrease in the percentage of senescent and advanced senescent cells in the SOD3-overexpressing cell population detected compared to that observed for the untransduced muscle-derived cells. A lower percentage of apoptotic cells was observed for transduced SkMDS/PCs than that for WT cells under hypoxic in vitro culture conditions. In transiently transfected SkMDS/PCs, we observed significantly higher gene expression levels of SOD2 (almost 40-fold) (p < 0.001) and FOXO (p < 0.05) (approximately 3-fold) under both normoxic and hypoxic culture conditions and of BCL2 under hypoxia compared to those observed in untreated cells (WT). In addition, myogenic genes showed a significant increase in MyoD (almost 18-fold) expression under standard culture conditions (p < 0.0001) and decreased MyoG expression (approximately 2-fold) after transfection (p < 0.05) compared with that detected in the WT skeletal muscle-derived cell control. Taken together, these results demonstrate that SOD3-tranduced skeletal muscle-derived cells may have potential for use in the regenerative treatment of the post-infarction heart.

Placenta growth factor and sFlt-1 as biomarkers in ischemic heart disease and heart failure: a review

Coronary heart disease (CHD) and heart failure (HF) produce significant morbidity/mortality but identifying new biomarkers could help in the management of each. In this article, we summarize the molecular regulation and biomarker potential of PIGF and sFlt-1 in CHD and HF. PlGF is elevated during ischemia and some studies have shown PlGF, sFlt-1 or PlGF:sFlt-1 ratio, when used in combination with standard biomarkers, strengthens predictions of outcomes. sFlt-1 and PlGF are elevated in HF with sFlt-1 as a stronger predictor of outcomes. Although promising, we discuss additional study criteria needed to confirm the clinical usefulness of PlGF or sFlt-1 in the detection and management of CHD or HF.