The regulation of cardiovascular development requires specific control of gene expression and heterozygous mutations of transcription factors have frequently been implicated in cardiovascular abnormalities. A novel mechanism involving post-transcriptional regulation by micro RNAs (mRNAs) has emerged as a central regulator of many cardiogenic processes. The researchers are beginning to understand the functions that micro RNAs play during cell proliferation, differentiation, apoptosis, stress response and formation of tumour. The identification of micro RNAs expressed in specific cardiac and vascular cell types has led to the discovery of important regulatory roles for these small RNAs during cardiac muscle differentiation, cell cycle, conduction and vessel formation.
1. Cardiac Hypertrophy
An experiment done to investigate the potential involvement of micro RNAs in cardiac hypertrophy….
Performed a micro RNA microarray analysis in two mouse models using a microarray that represented 186 different micro RNAs. In one model, mice were subjected to thoracic aortic banding (TAB) and were compared with the control (40). In a sec...
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...56). A study carried out by Thum et al showed that micro RNA 21 is increasing expressed in cardiac fibroblast (57). However, the exact role of micro RNA 21 remains unknown and many experiments have been carried out to understand the role of micro RNA 21.
Micro RNA 23a, 24 and 27 (51)
There are two micro RNA 23 genes in the human genome. Micro RNA 23 is expressed together with micro RNA 24 and micro RNA 27. Lin et al showed that micro RNA 23a, micro RNA 24, micro RNA 27a were up regulated in cardiac myocytes following addition of aldosterone or isoproterenol. However knockdown of micro RNA 24 and micro RNA 27a had no effect but knockdown of micro RNA 23 resulted in induced hypertrophy(58). Van Rooji and colleagues showed that the heart restricted the overexpression of micro RNA 24 suggesting an important role of micro RNA 24 in cardiac development (43).
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