| Talk title | To mend a broken heart, thou shalt learn from the ladies |
| Speaker | Prof. LAM Yun Wah Associate Professor Department of Chemistry, City University of Hong Kong |
| Date & Time | 25 October 2018 (Thurs) 14:15-15:15 |
| Venue | Room G003, E12 Building (University of Macau) |
| Abstract | Zebrafish is one of the most well-established animal models for heart regeneration. Here, we report the sexual dimorphism of zebrafish heart regeneration, with females regenerating their hearts faster than males. Estradiol treatment of males accelerated cardiac regeneration, while tamoxifen treatment of females reduced it. This sexual dimorphism was abolished by oxygen, suggesting the involvement of the Hypoxia-inducible factor 1a (HIF1a) pathway. Remarkably, cardiac damages induced plasma estrogen levels and the expression of estrogen receptor genes in zebrafish, leading to the feminisation of males, as evidenced by the detection of female-specific plasma proteins, including vitellogenins, in males during heart regeneration. Oxygen stimulated estrogen receptor expression in regenerating hearts in males, suggesting an interplay between the estrogen- and HIF1a-related mechanisms in heart regeneration. We show that vitellogenins were expressed in the liver and accumulated in damaged male hearts; but not in other wounds or in regenerating fins. Taken together, our data indicate that in zebrafish females are more efficient in mending broken hearts, and males are spontaneously feminised during heart regeneration. This unexpected phenomenon elucidates a previously unknown aspect of zebrafish tissue regeneration. |
