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Updated: Jun 10, 2026
In Vitro Differentiation of Human Mesenchymal Stem Cells into Functional Cardiomyocyte-like Cells
Published on: August 9, 2017
Human cardiac explant-conditioned medium: soluble factors and cardiomyogenic effect on mesenchymal stem cells
Andressa V Schittini1, Paola F Celedon, Marco A Stimamiglio
1Carlos Chagas Institute, R Prof Algacyr Munhoz Mader, FIOCRUZ, Curitiba, Brazil.
Insights
Human cardiac explant conditioned medium (CM) contains proteins that promote mesenchymal stem cell (MSC) proliferation and cardiac marker expression. This suggests a potential for new protein-based therapies in regenerative medicine.
Area of Science:
- Cardiovascular Biology
- Stem Cell Biology
- Regenerative Medicine
Background:
- The potential of conditioned medium (CM) from human cardiac explants (HCEs) for adult stem cell signaling is unexplored.
- HCE-CM may contain soluble factors that induce mesenchymal stem cell (MSC) differentiation into cardiomyocyte-like cells.
Purpose of the Study:
- To investigate the protein content of HCE-CM.
- To evaluate the effect of HCE-CM on bone marrow-derived MSC (BM-MSC) proliferation and differentiation into cardiomyocyte-like cells.
Main Methods:
- Two-dimensional electrophoresis (2-DE) with mass spectrometry
- Antibody macroarray assays
- Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE)
- In vitro culture of BM-MSCs with HCE-CM
- Analysis of cardiac marker gene and protein expression
Main Results:
- HCE-CM contains various macromolecules, including cytokines, growth factors, and myocardial proteins.
- Identified 20 proteins in HCE-CM, representing a fraction of the total protein content.
- HCE-CM significantly increased BM-MSC proliferation in vitro after 48 hours.
- A notable percentage (3.4-5.0%) of BM-MSCs treated with HCE-CM exhibited elongated morphology and expressed cardiac markers, indicating differentiation into cardiomyocyte-like cells.
Conclusions:
- HCE-CM contains bioactive proteins capable of promoting MSC proliferation and cardiac differentiation.
- This in vitro model offers insights into soluble factor-mediated cell differentiation mechanisms.
- HCE-CM holds promise for developing novel protein-based therapeutic strategies for cardiac regeneration.
Abstract:
The use of conditioned medium (CM) from human cardiac explants (HCEs) as a potential source of paracrine factors for adult stem cell signaling has never been evaluated. We hypothesized that HCEs might provide a source of soluble factors triggering the differentiation of mesenchymal stem cells (MSCs) into cardiomyocyte-like cells. By using two-dimensional electrophoresis (2-DE) gels/mass spectrometry and antibody macroarray assays, we found that HCEs release macromolecules, including cytokines, growth factors and myocardial and metabolism-related proteins into the culture medium. We identified a total of 20 proteins in the HCE-CM. However, as shown by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and 2-DE, these 20 proteins account for only a fraction of the total number of proteins present in the HCE-CM. We also found that CM increased the proliferation of bone marrow-derived-MSCs (BM-MSCs) in vitro. Unlike the other effects, this effect was most evident after 48 h of culture. Moreover, we examined the effect of HCE-CM on levels of mRNA and protein for specific cardiac markers. We showed that a surprisingly big fraction of BM-MSCs (3.4-5.0%) treated in vitro with HCE-CM became elongated and began to express cardiac markers, consistent with their possible differentiation into cardiomyocyte-like cells. Our in vitro model may be useful not only per se, but also for studies of the mechanisms of action of soluble factors involved in cell differentiation, paving the way for possible new protein-based treatments in the future.
