Bone microRNAs and Ageing.

The decline of tissue function in ageing is a consequence of many changes in the gene expression and other extrinsic factors. The molecular mechanisms underlying these changes are heavily investigated with focus on regulation of time-lapse gene expression. microRNAs, short non-coding RNA molecules, are among the major regulators of gene expression. microRNAs have been shown to control ageing-related mechanisms and several evidences suggest age-related changes in microRNA transcriptome. However, the source regulator of time-lapse gene expression control still remains unknown. Here, we have reviewed microRNA molecules related to the ageing of bones and studies that investigated age-related bone tissue gene expression. We identified 41 microRNA molecules from the literature that correlate with bone mineral density or fractures and one recent study has demonstrated how a combination of several microRNAs can be used for better prediction of the fractures in osteoporotic patients. The personalised diagnostic algorithms in the future should be therefore based on the combination of multiple biomarkers. Until now, little is known about the regulatory mechanisms of microRNA expression and genes in ageing. We have proposed a link between telomere length and gene expression profiles, however this now needs to be further investigated.