Robust and Highly Efficient Protocol for Differentiation of Human Pluripotent Stem Cells into Mesenchymal Stem Cells

Impact of adipose-derived stem cells on aortic tensile strength in a model of abdominal aortic aneurysm

Introduction

Abdominal Aortic Aneurysm (AAA) is a highly morbid condition and is the 11th leading cause of death in the United States. Treatment options are limited to operative interventions, with minimal non-operative options. Prior literature has demonstrated a benefit to the use of mesenchymal stem cells (MSCs) in attenuating AAA formation. We demonstrate the utility of MSCs in treating AAA in swine, focusing on the mechanical and structural characteristics of aortic tissue after treatment.

Methods

16 Yorkshire pigs underwent retroperitoneal exposure of the infrarenal aorta, with subsequent induction of AAA with peri-adventitial elastase and collagenase. A 1 × 4 cm piece of Gelfoam, an absorbable gelatin-based hemostatic agent, was soaked in media or human MSCs and placed directly on the vessel for control and experimental animals. At postoperative day 21, animals were sacrificed and the infrarenal aorta at this location was harvested for analysis. Tensile strength was measured using a tensiometer, from which Young's modulus and maximum strain were calculated.

Results

All animals survived the surgery and post-operative course. Young's elastic modulus for the aneurysm control group was 15.83 ± 1.61 compared to 22.13 ± 2.34 for the stem cell treated segment, p = 0.0316. There was no significant difference in the peak stress between groups.

Conclusions

This is the first study to demonstrate the mechanical effects of stem cell therapy on a model of AAA in swine. Young's modulus, which characterizes the intrinsic capacity of a tissue to withstand stress, was greater in the animals treated with MSCs compared to control animals with aneurysms. This methodology can be utilized in future large animal models to develop cell and drug-based therapies for AAA.

Potential application of mesenchymal stem cells and their exosomes in lung injury: an emerging therapeutic option for COVID-19 patients

The COVID-19 pandemic has negatively impacted the global public health and the international economy; therefore, there is an urgent need for an effective therapy to treat COVID-19 patients. Mesenchymal stem cells (MSCs) have been proposed as an emerging therapeutic option for the SARS-CoV-2 infection. Recently, numerous clinical trials have been registered to examine the safety and efficacy of different types of MSCs and their exosomes for treating COVID-19 patients, with less published data on the mechanism of action. Although there is no approved effective therapy for COVID-19 as of yet, MSC therapies showed an improvement in the treatment of some COVID-19 patients. MSC’s therapeutic effect is displayed in their ability to reduce the cytokine storm, enhance alveolar fluid clearance, and promote epithelial and endothelial recovery; however, the safest and most effective route of MSC delivery remains unclear. The use of poorly characterized MSC products remains one of the most significant drawbacks of MSC-based therapy, which could theoretically promote the risk for thromboembolism. Optimizing the clinical-grade production of MSCs and establishing a consensus on registered clinical trials based on cell-product characterization and mode of delivery would aid in laying the foundation for a safe and effective therapy in COVID-19. In this review, we shed light on the mechanistic view of MSC therapeutic role based on preclinical and clinical studies on acute lung injury and ARDS; therefore, offering a unique correlation and applicability in COVID-19 patients. We further highlight the challenges and opportunities in the use of MSC-based therapy.