Article

MicroRNA 218 Mediates the Effects of Tbx5a Over-Expression on Zebrafish Heart Development

Institute of Clinical Physiology, CNR, Pisa, Italy.
PLoS ONE (Impact Factor: 3.53). 11/2012; 7(11):e50536. DOI: 10.1371/journal.pone.0050536
Source: PubMed

ABSTRACT tbx5, a member of the T-box gene family, encodes one of the key transcription factors mediating vertebrate heart development. Tbx5 function in heart development appears to be exquisitely sensitive to gene dosage, since both haploinsufficiency and gene duplication generate the cardiac abnormalities associated with Holt-Oram syndrome (HOS), a highly penetrant autosomal dominant disease characterized by congenital heart defects of varying severity and upper limb malformation. It is suggested that tight integration of microRNAs and transcription factors into the cardiac genetic circuitry provides a rich and robust array of regulatory interactions to control cardiac gene expression. Based on these considerations, we performed an in silico screening to identify microRNAs embedded in genes highly sensitive to Tbx5 dosage. Among the identified microRNAs, we focused our attention on miR-218-1 that, together with its host gene, slit2, is involved in heart development. We found correlated expression of tbx5 and miR-218 during cardiomyocyte differentiation of mouse P19CL6 cells. In zebrafish embryos, we show that both Tbx5 and miR-218 dysregulation have a severe impact on heart development, affecting early heart morphogenesis. Interestingly, down-regulation of miR-218 is able to rescue the heart defects generated by tbx5 over-expression supporting the notion that miR-218 is a crucial mediator of Tbx5 in heart development and suggesting its possible involvement in the onset of heart malformations.

Download full-text

Full-text

Available from: Gaia Gestri, Jul 01, 2015
0 Followers
 · 
149 Views
  • [Show abstract] [Hide abstract]
    ABSTRACT: BACKGROUND: MiR-218 plays an important role in heart development in zebrafish. pri-miR-218 rs11134527 variant is associated with cervical cancer carcinogenesis. Therefore, we hypothesized that single nucleotide polymorphism (SNPs) in pri-miR-218 might influence susceptibility to sporadic congenital heart disease (CHD). METHODS AND RESULTS: We conducted a case-control study of CHD in a Chinese population to test our hypothesis by sequencing and genotyping pri-miR-218 in 1116 CHD cases and 1219 non-CHD controls. We identified one SNP rs11134527 located in pri-miR-218 sequence. Logistic regression analyses showed that there was no significant association in genotype and allele frequencies of pri-miR-218 rs11134527 A/G polymorphism between CHD cases in overall or various subtypes and the control group. However, Real-time PCR analysis showed that rs11134527 allele G significantly increased mature miR-218 expression. In vitro binding assays further revealed that the rs11134527 variant affects miR-218-mediated regulation of Robo1. Conclusions This is the first study to investigate the relationship between miR-218 and CHD cases. Our results demonstrate that the functional variant rs11134527 in pri-miR-218 has no major role in genetic susceptibility to sporadic CHD, at least in the population studied here.
    Gene 04/2013; 523(2). DOI:10.1016/j.gene.2013.03.119 · 2.08 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Heart development involves the precise orchestration of gene expression during cardiac differentiation and morphogenesis by evolutionarily conserved regulatory networks. miRNAs (microRNAs) play important roles in the post-transcriptional regulation of gene expression, and recent studies have established critical functions for these tiny RNAs in almost every facet of cardiac development and disease. The realization that miRNAs are amenable to therapeutic manipulation has also generated considerable interest in the potential of miRNA-based drugs for the treatment of a number of human diseases, including cardiovascular disease. In the present review, I discuss well-established and emerging roles of miRNAs in cardiac development, their relevance to congenital heart disease and unresolved questions in the field for future investigation, as well as emerging therapeutic possibilities for cardiac regeneration.
    Clinical Science 08/2013; 125(4):151-66. DOI:10.1042/CS20130011 · 5.63 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: microRNAs (miRNAs) are important both in early cardiogenesis and in the process of heart maturation. The aim of this study was to determine the stage-specific expression of miRNAs in human fetal heart in order to identify valuable targets for further study of heart defects. Affymetrix microarrays were used to obtain miRNA expression profiles from human fetal heart tissue at 5, 7, 9 and 23 weeks of gestation. To identify differentially expressed miRNAs at each time-point, linear regression analysis by the R limma algorithm was employed. Hierarchical clustering analysis was conducted with Cluster 3.0 software. Gene Ontology analysis was carried out for miRNAs from different clusters. Commonalities in miRNA families and genomic localization were identified, and the differential expression of selected miRNAs from different clusters was verified by quantitative polymerase chain reaction (qPCR). A total of 703 miRNAs were expressed in human fetal heart. Of these, 288 differentially expressed miRNAs represented 5 clusters with different expression trends. Several clustered miRNAs also shared classification within miRNA families or proximal genomic localization. qPCR confirmed the expression patterns of selected miRNAs. miRNAs within the 5 clusters were predicted to target genes vital for heart development and to be involved in cellular signaling pathways that affect heart structure formation and heart-associated cellular events. In conclusion, to the best of our knowledge, this is the first miRNA expression profiling study of human fetal heart tissue. The stage-specific expression of specific miRNAs suggests potential roles at distinct time-points during fetal heart development.
    International Journal of Molecular Medicine 03/2014; 33(5). DOI:10.3892/ijmm.2014.1691 · 1.88 Impact Factor