# Stem Cells Associated with Adult Skeletal Muscle Can Form Beating Cardiac Tissue In Vitro in Response to Media Containing Heparin, Dexamethasone, Growth Factors and Hydrogen Peroxide

## TL;DR

Researchers found that adult skeletal muscle stem cells can be turned into beating heart-like tissue in the lab using a specific mix of chemicals.

## Contribution

A novel, simple in vitro method to convert skeletal muscle-derived stem cells into contractile cardiac tissue is introduced.

## Key findings

- Skeletal muscle-derived stem cells formed beating myospheres under specific culture conditions.
- The cardiogenic phenotype was maintained for over four months in vitro.
- The method offers a new model for studying cardiac and skeletal muscle divergence.

## Abstract

Both cardiac and skeletal muscles originate from the mesoderm, although the two tissues develop from distinct primordia within the early embryo. The shared, albeit distinctive muscle phenotype of these two cell types have led many researchers to investigate whether stem cells from adult skeletal muscle have the capacity to generate cells with a contractile, cardiac phenotype. To date, most of those studies have relied on multistep protocols requiring tissue engineering, co-cultures or transplantation experimentation. In this report, we describe a simple, cell culture method for obtaining contractile, cardiogenic aggregates from skeletal muscle-derived stem cells (MDSCs). Combining in vitro conditions used for promoting the differentiation of cardiac progenitor cells and the long-term maintenance of heart tissue fragments, we have been able to convert MDSCs to myocardial cells that aggregate into beating myospheres. These selective and optimized culture conditions continued to support a contractile cardiogenic phenotype for over four months in vitro. This culture protocol provides a model for future insights into the pathways responsible for the divergence of skeletal and cardiac phenotypes, as well as a source of easily obtained myocardial tissue for subsequent scientific investigations into cardiac function and biology.