A p53-based genetic tracing system to follow postnatal cardiomyocyte expansion in heart regeneration

Abstract

In the field of heart regeneration, the proliferative potential of cardiomyocytes in postnatal mice is under intense investigation. However, solely relying on immunostaining of proliferation markers, the long-term proliferation dynamics and potential of the cardiomyocytes cannot be readily addressed. Previously, we found that a p53 promoter-driving reporter predominantly marked the proliferating lineages in mice. Here, we established a p53-based genetic tracing system to investigate postnatal cardiomyocyte proliferation and heart regeneration. By selectively tracing proliferative cardiomyocytes, a differential pattern of clonal expansion in p53 + cardiac myocytes was revealed in neonatal, adolescent and adult stages. In addition, the percentage of p53 + lineage cardiomyocytes increased continuously in the first month. Furthermore, these cells rapidly responded to heart injury and greatly contributed to the replenished myocardium. Therefore, this study reveals complex proliferating dynamics in postnatal cardiomyocytes and heart repair, and provides a novel genetic tracing strategy for studying postnatal cardiac turnover and regeneration.

p53 isoform Δ113p53 promotes zebrafish heart regeneration by maintaining redox homeostasis

“…P53 and its isoform Δ133p53/Δ113p53 play a critical role in the maintenance of redox homeostasis by regulating the expression of antioxidant genes 46 . Interestingly, ROS are also generated during zebrafish heart regeneration to promote cardiomyocyte proliferation 16 , and the p53 signalling pathway is activated during cardiac regeneration in neonatal mice 47 . However, how redox homeostasis is maintained and whether p53 signalling plays a role in heart regeneration remain unclear.…”

“…In this report, we applied partial zebrafish ventricular resection to investigate the function of Δ113p53 in heart regeneration. Based on a p53-based genetic tracing system involving the insertion of a CreER cassette immediately after the first ATG of the full-length mouse p53 BAC clone (located in the second exon of p53), a previous study revealed that full-length p53-positive cardiomyocytes are activated by injury in neonatal mice and undergo proliferation to contribute to heart regeneration 47 . In contrast, using Δ113p53 transgenic reporter fish, in situ hybridisation and qRT-PCR, we found that the transcription of Δ113p53, but not full-length p53, was induced in cardiomyocytes near the injury site in zebrafish ventricles (Fig.…”

“…A study in mice showed that p53 signalling is activated in cardiomyocytes during neonatal mouse heart regeneration 47 . However, the roles p53 signalling plays and whether its isoforms are activated in heart regeneration are unknown.…”

HAND2-mediated epithelial maintenance and integrity in cardiac outflow tract morphogenesis

“…Histological sections were stained with Hematoxylin and Eosin (H&E) or used for TUNEL, IF and immunohistochemical (IHC) analysis. IF and IHC were carried out using standard procedures (Xiao et al, 2017). Embryos were fixed in 4% PFA, then rinsed in PBS and incubated in 30% sucrose at 4°C until sinking.…”

The Effect of Hypoxia on Cardiovascular Disease: Friend or Foe?

“…Studies of the neonatal mammalian heart establish a short window of time immediately after birth, in which significant cardiomyocyte proliferation can occur even after injury. Cardiac injury that occurs after this window has passed results in fibrosis and scar formation (Porrello et al, 2011(Porrello et al, , 2013Xin et al, 2013;Aurora et al, 2014;Bryant et al, 2015;Darehzereshki et al, 2015;Mahmoud et al, 2015;O'Meara et al, 2015;Polizzotti et al, 2015;Xiao et al, 2017).…”