Published online Aug 26, 2022. doi: 10.4252/wjsc.v14.i8.633
Peer-review started: March 18, 2022
First decision: April 25, 2022
Revised: May 9, 2022
Accepted: July 8, 2022
Article in press: July 8, 2022
Published online: August 26, 2022
Processing time: 160 Days and 18.9 Hours
Cardiovascular diseases are the leading cause of death globally. Adult heart tissue possesses impaired self-renewal capability and thus shows inadequate capability of restoring its structure and function after injury. Stem cell based therapy to treat cardiac injuries has achieved moderate success due to some limitations. Cardiac tissue engineering constructs the cardiac patch or scaffold to restore cardiac function following injury. Mesenchymal stem cells (MSCs) have great potential to be used for myocardial regeneration due to their multilineage differentiation potential. Controlled fate of grafted cells can be achieved by inducing in vitro cardiac differentiation by demethylating agent such as zebularine.
MSCs are potential candidates for the regeneration of damaged cardiac tissue but their insufficient survival and engraftment at the injured tissue is a major hurdle. This can be overcome by pre-differentiation of MSCs using a demethylating agent and providing three-dimensional (3D) microenvironment through biological scaffold. In vivo transplantation of pre-differentiated cell seeded scaffold can provide mechanical support and enhance cell survival, engraftment and regeneration of cardiac tissue and pave the way to develop an improved cardiovascular therapeutic strategy.
The study was aimed to enhance the differentiation of MSCs by treating them with demethylating agent, zebularine, in a 3D microenvironment provided by collagen scaffold and subsequent enhancement of cell engraftment, survival and myocardial regeneration upon in vivo transplantation in the rat myocardial infarction (MI) model.
MSCs were isolated from rat bone marrow and characterized on the basis of specific cell surface markers and trilineage differentiation potential. MSCs were seeded in collagen scaffold and treated with zebularine to induce cardiac differentiation. MSC-seeded scaffolds were transplanted in the rat MI model. Cardiac function assessment was done by echocardiographic analysis and ventricular regeneration by histological analysis. Neovascularization was analyzed by immunohistochemistry with α-smooth muscle actin staining. DiI labeled cell seeded scaffolds were transplanted to track the cells and their in vivo cardiac differentiation was analyzed by immunohistochemistry.
In vitro results showed significantly enhanced cardiac differentiation of MSCs after zebularine treatment in 3D culture. Transplantation of pre-differentiated MSC-seeded collagen scaffold in the rat MI model improved cardiac function more efficiently than the untreated MSC-seeded collagen scaffold group. Histological analysis also showed improvement in myocardial regeneration, ventricular wall thickness and reduction in fibrotic tissue. Immunohistochemical analysis showed significantly enhanced vasculature and in vivo cardiac differentiation of transplanted MSCs in zebularine treated MSC-seeded collagen scaffold group.
Pre-differentiation of MSC-seeded collagen scaffold transplantation improves cardiac function, preserves ventricular remodeling and enhances myocardial regeneration after acute MI. This strategy provided the 3D microenvironment to the transplanted cells, enhanced their survival and engraftment at the injured tissue, as well as increased blood supply by forming a new vascular system.
The combination approach using pre-differentiated MSCs and the 3D collagen scaffold can open a new insight to repair the damage caused by ischemic cardiovascular injuries.