MicroRNA-375 overexpression disrupts cardiac development of Zebrafish (Danio rerio) by targeting notch2
Sisi Zhuang1,2, Yanrong Fu3, Jingyun Li1
1Department of Child Health Care, Women's Hospital of Nanjing Medical University, Nanjing Maternity and Child Health Care Hospital, 123rd Tianfei Street, Mochou Road, Nanjing, 210004, China.
Abstract:
MicroRNAs are small noncoding RNAs that are important for proper cardiac development. In our previous study of fetuses with ventricular septal defects, we discovered that microRNA-375 (miR-375) is obviously upregulated compared with that in healthy controls. Our study also confirmed that miR-375 is crucial for cardiomyocyte differentiation. This research mainly focused on the biological significance and mechanism of miR-375 using a zebrafish model. We injected zebrafish embryos with 1-2 nl of a miR-375 mimic at various concentrations (0/2/4/8 μM) or with negative control. The deformation and mortality rates were separately assessed. The different expression levels of miR-375 and related genes were examined by qRT-PCR, and luciferase assays and in situ hybridization were used to clarify the mechanism of miR-375 during embryonic development. Overexpression of miR-375 disrupted the cardiac development of zebrafish embryos. Disruption of miR-375 led to a decreased heart rate, pericardial edema, and abnormal cardiac looping. Various genes involved in cardiac development were downregulated due to the overexpression of miR-375. Moreover, the NOTCH signaling pathway was affected, and the luciferase reporter gene assays confirmed notch2, which was predicted by bioinformatics analysis, as the target gene of miR-375. Our findings demonstrated that the overexpression of miR-375 is detrimental to embryonic development, including cardiac development, and can partially simulate a multisystemic disorder. MiR-375 has an important role during cardiac morphogenesis of zebrafish embryos by targeting notch2, indicating its potential as a diagnostic marker.
Insights
Overexpression of microRNA-375 (miR-375) disrupts embryonic cardiac development in zebrafish, affecting heart rate and morphology. MiR-375 targets notch2, highlighting its role in cardiac morphogenesis and potential as a diagnostic marker.
Area of Science:
- Developmental biology
- Molecular biology
- Cardiovascular research
Background:
- MicroRNAs regulate cardiac development.
- MicroRNA-375 (miR-375) is upregulated in fetuses with ventricular septal defects.
- miR-375 is crucial for cardiomyocyte differentiation.
Purpose of the Study:
- Investigate the biological significance and mechanism of miR-375 in zebrafish embryonic development.
- Determine the impact of miR-375 overexpression on cardiac morphogenesis.
- Identify the target genes and pathways regulated by miR-375.
Main Methods:
- Zebrafish embryo injection with miR-375 mimic or control.
- Assessment of deformation and mortality rates.
- Quantitative real-time PCR (qRT-PCR) for gene expression analysis.
- Luciferase assays and in situ hybridization to elucidate molecular mechanisms.
Main Results:
- Overexpression of miR-375 led to cardiac developmental disruption, including decreased heart rate, pericardial edema, and abnormal cardiac looping.
- Genes critical for cardiac development were downregulated upon miR-375 overexpression.
- The NOTCH signaling pathway was affected, with notch2 identified as a direct target of miR-375 via luciferase assays.
Conclusions:
- Overexpression of miR-375 is detrimental to embryonic cardiac development in zebrafish.
- MiR-375 plays a significant role in cardiac morphogenesis by targeting notch2.
- MiR-375 shows potential as a diagnostic marker for cardiac developmental disorders.
