Conditioned medium harvested from Hif1α engineered mesenchymal stem cells ameliorates LAD-occlusion -induced injury in rat acute myocardial ischemia model

Mitoprotective effect of mesenchymal stem cells-derived conditioned medium in myocardial reperfusion injury of aged rats: role of SIRT-1/PGC-1α/NRF-2 network

BACKGROUND

The aged myocardium experiences various forms of stress that cause reduction of its tolerance to injury induced by ischemia/reperfusion (I/R). Developing effective cardioprotective modalities to prevent the amplification of I/R injury during aging is under focus of investigation. Mesenchymal stem cells (MSCs) have the ability to regenerate infarcted myocardium mostly by producing multiple secretory factors. This study aimed to explore the mechanisms of mitoprotection by MSCs-conditioned medium (CM) in myocardial I/R injury of aged rats.

METHODS

Male Wistar rats (n = 72, 400-450 g, 22-24 months old) were randomized into groups with/without I/R and/or MSCs-CM treatment. To establish myocardial I/R injury, the method of LAD occlusion and re-opening was employed. MSCs-CM was administered intramyocardially (150 μl) at the onset of reperfusion in recipient group. After 24 h reperfusion, myocardial infarct size, LDH level, mitochondrial functional endpoints, expression of mitochondrial biogenesis-associated genes, and the levels of pro-inflammatory cytokines were evaluated. After 28 days reperfusion, echocardiographic assessment of cardiac function was performed.

RESULTS

MSCs-CM treatment improved myocardial function and decreased infarct size and LDH level in aged I/R rats (P < .05 to P < .001). It also decreased mitochondrial ROS formation, enhanced mitochondrial membrane potential and ATP content, upregulated mitochondrial biogenesis-related genes including SIRT-1, PGC-1α, and NRF-2, and lessened TNF-α, IL-1β, and IL-6 levels (P < .05 to P < .01).

CONCLUSIONS

MSCs-CM treatment attenuated myocardial I/R injury in aged rats, in part by improving mitochondrial function and biogenesis and restraining inflammatory reaction. the upregulation of SIRT-1/PGC-1α/NRF-2 profiles is a possible target for the mitoprotective effects of MSCs-CM following I/R injury during aging.

Hypoxia-inducible factor 1-alpha enhances the secretome to rejuvenate adult cardiosphere-derived cells

OBJECTIVE

After cardiac injury, endogenous repair mechanisms are ineffective. However, cell-based therapies provide a promising clinical intervention based on their ability to restore and remodel injured myocardium due to their paracrine factors. Recent clinical trials have demonstrated that adult cardiosphere-derived cell therapy is safe for the treatment of ischemic heart failure, although with limited regenerative potential. The limited efficiency of cardiosphere-derived cells after myocardial infarction is due to the inferior quality of their secretome. This study sought to augment the therapeutic potential of cardiosphere-derived cells by modulating hypoxia-inducible factor-1α, a regulator of paracrine factors.

METHODS

Cardiosphere-derived cells were isolated and expanded from the right atrial appendage biopsies of patients undergoing cardiac surgery. To study the effect of hypoxia-inducible factor-1α on the secretome, cardiosphere-derived cells were transduced with hypoxia-inducible factor-1α-overexpressing lentivirus, and various cardioprotective factors within the secretome were quantified using enzyme-linked immunosorbent assays. Comparative analysis of the regenerative potential of cardiosphere-derived cells was performed in a rat myocardial infarction model.

RESULTS

Mechanistically, overexpression of hypoxia-inducible factor-1α in adult cardiosphere-derived cells led to the enrichment of the secretome with vascular endothelial growth factor A, angiopoietin 1, stromal cell-derived factor 1α, and basic fibroblast growth factor. Intramyocardial administration of cardiosphere-derived cells transduced with hypoxia-inducible factor-1α after myocardial infarction significantly improved left ventricular ejection fraction, fractional shortening, left ventricular end-systolic volume, and cardiac output. Functional improvement of the rat heart correlated with improved adaptive remodeling of the infarcted myocardium by enhanced angiogenesis and decreased myocardial fibrosis. We also showed that hypoxia-inducible factor-1α expression in cardiosphere-derived cells was adversely affected by aging.

CONCLUSIONS

Hypoxia-inducible factor-1α improves the functional potency of cardiosphere-derived cells to preserve myocardial function after myocardial infarction by enriching the cardiosphere-derived cells' secretome with cardioprotective factors. This strategy may be useful for improving the efficacy of allogeneic cell-based therapies in future clinical trials.

Increasing angiogenic efficacy of conditioned medium using light stimulation of human adipose-derived stem cells

Conditioned medium (CM) contains various therapeutic molecules produced by cells. However, the low concentration of therapeutic molecules in CM is a major challenge for successful tissue regeneration. Here, we aim to develop a CM enriched in angiogenic paracrine factors for the treatment of ischemic diseases. Combining spheroidal culture and light irradiation significantly upregulates the angiogenic factor expression in human adipose-derived stem cells (hADSCs). Spheroids of light-irradiated hADSCs (SR group) show significantly enhanced expression of angiogenic paracrine factors compared with spheroids without light stimulation. Enhanced viability, migration, and angiogenesis are observed in cells treated with CM derived from the SR group. Furthermore, we performed in vivo experiments using a mouse hindlimb ischemia model; the results demonstrate that CM derived from densely cultured spheroids of light-irradiated hADSCs induced increased angiogenesis in vivo. In conclusion, our proposed approach of using light to stimulate stem cells may overcome the major drawbacks of CM-based therapies.

Combining spheroidal culture of human adipose-derived stem cells with light irradiation enhances angiogenic growth factor secretion in conditioned media, which can improve angiogenesis in a mouse hindlimb ischemia model.

Paracrine Factors Released by Stem Cells of Mesenchymal Origin and their Effects in Cardiovascular Disease: A Systematic Review of Pre-clinical Studies

Mesenchymal stem cell (MSC) therapy has gained significant traction in the context of cardiovascular repair, and have been proposed to exert their regenerative effects via the secretion of paracrine factors. In this systematic review, we examined the literature and consolidated available evidence for the “paracrine hypothesis”. Two Ovid SP databases were searched using a strategy encompassing paracrine mediated MSC therapy in the context of ischemic heart disease. This yielded 86 articles which met the selection criteria for inclusion in this study. We found that the MSCs utilized in these articles were primarily derived from bone marrow, cardiac tissue, and adipose tissue. We identified 234 individual protective factors across these studies, including VEGF, HGF, and FGF2; which are proposed to exert their effects in a paracrine manner. The data collated in this systematic review identifies secreted paracrine factors that could decrease apoptosis, and increase angiogenesis, cell proliferation, and cell viability. These included studies have also demonstrated that the administration of MSCs and indirectly, their secreted factors can reduce infarct size, and improve left ventricular ejection fraction, contractility, compliance, and vessel density. Furthering our understanding of the way these factors mediate repair could lead to the identification of therapeutic targets for cardiac regeneration.

Taming of Covid-19: potential and emerging application of mesenchymal stem cells

Coronavirus Disease 2019 (COVID-19) caused by the Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) has turned out to cause a pandemic, with a sky scraping mortality. The virus is thought to cause tissue injury by affecting the renin-angiotensin system. Also, the role of the over-activated immune system is noteworthy, leading to severe tissue injury via the cytokine storms. Thus it would be feasible to modulate the immune system response in order to attenuate the disease severity, as well as treating the patients. Today different medicines are being administered to the patients, but regardless of the efficacy of these treatments, adverse effects are pretty probable. Meanwhile, mesenchymal stem cells (MSCs) prove to be an effective candidate for treating the patients suffering from COVID-19 pneumonia, owing to their immunomodulatory and tissue-regenerative potentials. So far, several experiments have been conducted; transplanting MSCs and results are satisfying with no adverse effects being reported. This paper aims to review the recent findings regarding the novel coronavirus and the conducted experiments to treat patients suffering from COVID-19 pneumonia utilizing MSCs.