Study type: In vivo/preclinical · Status: Verified against declared source

Thymosin β4 and prothymosin α promote cardiac regeneration post-ischaemic injury in mice.

Cardiovascular research · 2023

Study scale: Animal studies were performed according to the guidelines from Directive 2010/63/EU of the European Parliament on the protection of animals used for scientific purposes.

Abstract only: Open source record

Product or molecular entity relationships

  • Thymosin Beta-4 (TB500): Exact entity relationship. Legacy citation custody associates this source with the catalog record; no product-relevance conclusion is implied.

Plain-language verified summary

Question

The adult mammalian heart is a post-mitotic organ.

Methods

For cardiomyocyte cell size and proliferation status, 4μm paraffin embedded hearts were analyzed in the four-chamber view of the heart.

Scale or participants

Animal studies were performed according to the guidelines from Directive 2010/63/EU of the European Parliament on the protection of animals used for scientific purposes.

Key findings

Here, we demonstrate increased 5-ethynyl-2’deoxyuridine incorporation in cardiomyocytes 3 days post-myocardial infarction in mice.

Limitations and uncertainty

During mammalian cardiac maturation, cardiomyocytes lose their proliferative capacity1,2 and retain a low basal turnover rate (less than 1% annually).3–5 While it is known that the mitogenic activity of cardiomyocytes increases in response to ischaemic injuries, this does not result in a sufficient amount of cell division for adequate regeneration, but rather polyploidization and multinucleation.6,7 In contrast to the adult heart, mammalian neonates and invertebrates can regenerate the myocardium by de-differentiation and proliferation of existing cardiomyocytes.8,9 Thus, efforts to try to promote cardiomyocyte cell-cycle re-entry in adult mammalian hearts have become a key focus within the field.10 To date, several studies have focused on characterizing the transcriptomic signature of proliferating cardiomyocytes in young neonates and invertebrates to provide insight into potential mechanisms to stimulate adult cardiomyocyte regeneration.8,11–13 However, less is known about the gene profile of adult proliferating cardiomyocytes and whether this can be utilized to uncover specific genes relevant for promoting cytokinesis in these highly organized cells.

Verified against declared source. Verification is limited to the declared source and review scope. It does not mean independent replication or establish efficacy, safety, or suitability.