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Updated: Jun 17, 2025
Isolation and Characterization of Single Cells from Zebrafish Embryos
Published on: March 12, 2016
Cxcr4a regulates heart progenitor development and cardiac rhythm in zebrafish
Bingyu Chen1,2, Qin Ran3, Xin Chen2
1Sichuan Integrated Medicine Hospital, Chengdu, 610041, Sichuan, China.
Insights
The chemokine receptor Cxcr4a regulates heart progenitor determination and cardiac rhythm. Upregulated retinoic acid signaling in cxcr4a mutants mediates these effects on heart development.
Area of Science:
- Developmental Biology
- Cardiovascular Biology
- Molecular Biology
Background:
- The chemokine receptor Cxcr4a is known to play roles in organ development, including coronary vasculature formation and heart left-right patterning.
- Its specific involvement in heart progenitor determination and cardiac rhythm regulation remains unaddressed.
Purpose of the Study:
- To investigate the role of Cxcr4a in heart progenitor determination and cardiac rhythm regulation.
- To elucidate the underlying molecular mechanisms, particularly the involvement of retinoic acid (RA) signaling.
Main Methods:
- Analysis of cxcr4a mutant zebrafish embryos at various developmental stages (dpf, hpf, Somite Stage).
- Gene expression analysis using RT-qPCR and in situ hybridization.
- RNA sequencing (RNA-seq) to identify molecular pathways.
- Pharmacological manipulation with retinoic acid (RA).
Main Results:
- cxcr4a mutants exhibited transient pericardial edema and increased cardiac rhythm from 2 to 4 days post fertilization (dpf).
- Reduced expression of myl7 and decreased heart progenitors were observed at 36-48 hours post fertilization (hpf) and 18 Somite Stage (SS), respectively.
- Upregulated retinoic acid (RA) signaling was detected in cxcr4a mutants, potentially mediating the observed phenotypes.
- Low-dose RA treatment mimicked the accelerated cardiac rhythm in mutants, and decreasing RA signaling partially rescued this phenotype.
Conclusions:
- Cxcr4a plays a simultaneous role in regulating heart progenitor determination and cardiac rhythm.
- Retinoic acid (RA) signaling is implicated as a key mediator in Cxcr4a's regulation of heart development and function.
Abstract:
Cxcr4a is involved in multiple organ development including coronary vasculature formation and heart left-right (LR) patterning, whether it is involved in heart progenitor determination and cardiac rhythm regulation is not addressed. Here we showed that in cxcr4a mutants, from 2 days post fertilization (dpf) to 4dpf the embryos transiently displayed pericardial edema and increased cardiac rhythm. While from 5dpf, the heart phenotype disappeared. Detailed analysis demonstrated that, at 36hpf and 48hpf, even though there was no distinct difference in the heart size between cxcr4a mutants and controls, the expression of myl7 was decreased. Further data showed that, the heart progenitors were decreased at 18SS(Somite Stage). Mechanically, RNA-seq, RT-qPCR and in situ experiments showed that the retinoic acid (RA) signaling was upregulated, and the up-regulation of RA signaling may mediate the role of cxcr4a in regulating heart progenitor development. In addition, we also identified that low dose of RA treatment accelerated the cardiac rhythm, being similar to that in cxcr4a mutants. Decreasing RA signaling partially restored the rapid cardiac rhythm in cxcr4a mutants, implying the possibility that RA signaling partially mediates the role of cxcr4a in regulating cardiac rhythm. In conclusion, our study identified cxcr4a simultaneously regulates heart progenitor determination and cardiac rhythm.
