CXXC5 is required for cardiac looping relating to TGFβ signaling pathway in zebrafish

Xiyang Peng1, Guanming Li1, Yuequn Wang1

  • 1The Center for Heart Development, Key Lab of MOE for Development Biology and Protein Chemistry, College of Life Sciences, Hunan Normal University, Changsha, Hunan 410081, China.

Abstract

Insights

CXXC5 protein is crucial for heart development in zebrafish, regulating cardiac looping through the Tgfβ signaling pathway. This finding highlights CXXC5

Area of Science:

  • Molecular Biology
  • Developmental Biology
  • Cardiovascular Research

Background:

  • CXXC-type zinc-finger protein CXXC5 is linked to cardiovascular disease.
  • CXXC5 activates both Tgfβ and myocardial differentiation pathways.
  • The specific role of CXXC5 in heart development was previously unknown.

Purpose of the Study:

  • To investigate the function of CXXC5 in heart development.
  • To elucidate the molecular mechanisms by which CXXC5 influences cardiogenesis.

Main Methods:

  • Investigated interactions between zebrafish CXXC5 and SMAD proteins.
  • Assessed Tgfβ signaling pathway activity via luciferase reporter assays.
  • Analyzed CXXC5 expression patterns during zebrafish cardiogenesis.
  • Utilized morpholino-mediated knockdown of cxxc5 to observe developmental defects.
  • Examined the rescue effect of hand2 mRNA co-injection.

Main Results:

  • CXXC5 interacts with SMAD proteins.
  • CXXC5 enhances Tgfβ signaling pathway activity in cardiomyocytes.
  • cxxc5 is expressed throughout zebrafish cardiogenesis.
  • cxxc5 knockdown leads to cardiac looping defects, dysplasia, and reduced contractility.
  • Cardiac development defects in cxxc5 knockdown embryos are associated with downregulated Tgfβ target genes (nkx2.5, hand2, has2).
  • Co-injection of hand2 mRNA rescues cardiac looping defects in cxxc5 morphants.

Conclusions:

  • This study provides the first in vivo evidence of CXXC5 regulating heart development and cardiac looping via the Tgfβ signaling pathway.
  • CXXC5 may serve as a potential diagnostic and prognostic marker for congenital heart disease in fetuses.