Late Breaking Abstract - 3D culturing mesenchymal stem cells in lung extracellular matrix hydrogels affects their homing potential

Abstract

Introduction: The main hypothesis in mesenchymal stem cells (MSCs)-based therapy is that cells produce mainly a paracrine effect by secreting immunomodulatory factors. Nevertheless, their low capacity for homing in the damaged tissue is a huge concern. Our aim is to investigate how preconditioning these MSCs by 3D culturing them in porcine lung-derived hydrogels can improve their homing potential.

Methods: Rat primary lung resident MSCs were cultured in 3D in porcine lung extracellular matrix (ECM) hydrogels with a stiffness of 0.7kPa. After seven days of 3D culture, cells were harvested by digesting the scaffolds using collagenase. Cell adhesion and actin/paxillin staining tests were conducted with the harvested and control cells by seeding them onto specific well-plates for optical imaging and allowed to attach to the plate for 2h. The expression of surface chemokine receptor CXCR4 was quantified by qRT-PCR.

Results: Compared to cells cultured in standard tissue culture plates, cells harvested from the lung hydrogel scaffolds formed focal adhesions two times longer. Besides, ten times more cells were adhered to the substrate after 2h. Finally, the expression of CXCR4 chemokine receptor was increased by more than twenty-fold in the preconditioned cells.

Conclusions: The data indicate that culturing lung MSCs in the ECM has a major impact in their adhesion capacity and the expression of one the main receptors involved in cell homing in vivo. Thus, lung ECM-derived hydrogels have the potential to be used as a bioreactor to precondition cells prior to transplant and to develop in vitro models to better understand homing mechanisms in MSCs.