The role of vitamins and minerals in modulating the expression of microRNA.
A growing number of studies in recent years have highlighted the importance of molecular nutrition as a potential determinant of health and disease. In particular, the ability of micronutrients to regulate the final expression of gene products via modulation of transcription and translation is now being recognised. Modulation of microRNA (miRNA) by nutrients is one pathway by which nutrition may mediate gene expression. miRNA, a class of non-coding RNA, can directly regulate gene expression post-transcriptionally. In addition, miRNA are able to indirectly influence gene expression potential at the transcriptional level via modulation of the function of components of the epigenetic machinery (DNA methylation and histone modifications). These mechanisms interact to form a complex, bi-directional regulatory circuit modulating gene expression. Disease-specific miRNA profiles have been identified in multiple disease states, including those with known dietary risk factors. Therefore, the role that nutritional components, in particular, vitamins and minerals, play in the modulation of miRNA profiles, and consequently health and disease, is increasingly being investigated, and as such is a timely subject for review. The recently posited potential for viable exogenous miRNA to enter human blood circulation from food sources adds another interesting dimension to the potential for dietary miRNA to contribute to gene modulation.