Introduction:
Use of cardiac mesenchymal cells (CMCs) has been shown to improve cardiac function following myocardial infarction. Main drawback in cardiac cell therapy is the major loss of injected cells within few hours. Increase the retention of these injected cells could increase their efficacy, where cardiac patches with various cell types showed better outcome. Among, collagen patch plays lead role as a cell-laden matrix in cardiac tissue engineering. Creating a detailed understanding of how collagen matrix changes the cellular phenotype could provide seminal insights to regeneration therapy.
Hypothesis:
Growing CMCs in three dimensional (3D) collagen matrix could alter the expression of extracellular matrix (ECM) and adhesion molecules, which may enhance their efficacy.
Methods:
The bovine type I collagen was chemically modified and solubilized in culture medium with photo-initiator. The mouse CMCs were isolated and resuspended in collagen solution, printed using 3D bioprinter and UV-crosslinked to form 3D-CMC construct. The 3D-CMC construct was submerged in growth medium and cultured for 48h and analyzed for the expression of ECM and adhesion molecules (n=5/group). CMCs cultured in regular plastic tissue culture dish was used as control.
Results:
RT profiler array showed changes in the ECM and adhesion molecules expression, specifically certain integrins and matrix metalloproteinases (MMPs) in CMCs cultured 3D collagen construct compared to 2D monolayer. Subsequent qRT-PCR analysis revealed significant (p<0.01) upregulation of integrins such as Itga2 (2.96±0.13), Itgb1 (3.18±0.2) and Itgb3 (2.4±0.27) and MMPs such as MMP13 (37.2±3.36), MMP9 (5.23±1.06) and MMP3 (7.14±2.07). Western blot analysis further confirmed significant elevation of these integrins and matrix metalloproteinases at protein level. Collagen encapsulation did not alter the expression of N-cadherin in CMCs, which is a potential mesenchymal cadherin adhesion molecule.
Conclusion:
Integrin αβ heterodimers transduce signals that facilitate cell homing, migration, survival and differentiation. Similarly, MMPs plays vital role in cell migration and proliferation. Our results demonstrate that the 3D-collagen Niche enhances the expression of certain integrins and MMPs in CMCs. This suggest that the efficacy of CMCs could be magnified by providing 3D architecture with collagen matrix and further in vivo experiments would reveal functional benefits from CMCs for clinical use.
Planar Gradient Diffusion System to Investigate Chemotaxis in a 3D Collagen Matrix