MicroRNA expression in the aging mouse lung.

Mark A Lindsay,Mark M Perry,Sterghios A Moschos,Andrew E Williams

doi:10.1186/1471-2164-8-172

Abstract

BackgroundMicroRNAs (miRNAs) are a novel class of short double stranded RNA that mediate the post-transcriptional regulation of gene expression. Previous studies have implicated changes in miRNA expression in the regulation of development and the induction of diseases such as cancer. However, although miRNAs have been implicated in the process of aging in C. elegans, nothing is known of their role in mammalian tissues.ResultsTo address this question, we have used a highly-sensitive, semi-quantitative RT-PCR based approach to measure the expression profile of 256 of the 493 currently identified miRNAs in the lungs from 6 month (adult) and 18 month (aged) old female BALB/c mice. We show that, despite the characteristic changes in anatomy and gene expression associated with lung aging, there were no significant changes in the expression of 256 miRNAs.ConclusionOverall, these results show that miRNA transcription is unchanged during lung aging and suggests that stable expression of miRNAs might instead buffer age related changes in the expression of protein-encoding genes.

Highlights

MicroRNAs are a novel class of short double stranded RNA that mediate the post-transcriptional regulation of gene expression
We have previously shown that the miRNA expression profile differs significantly between the fetal and adult lung [19]
Structural changes were evident in accordance with aged lung tissue and included enlargement of alveolar spaces associated with a decrease in total surface area (Figure 1A– B)

Summary

Introduction

MicroRNAs (miRNAs) are a novel class of short double stranded RNA that mediate the post-transcriptional regulation of gene expression. 493 miRNAs have been identified in mammalian tissues (Sanger Institute miRNA Registry, Release 9.1, February 2007) [1] and shown to regulate the post-transcriptional expression of multiple genes through a mechanism similar to RNA interference (RNAi) [2,3]. Post-transcriptional regulation of gene expression is mediated by the RNA-induced silencing complex (RISC), which uses one strand of the miRNA molecule (the guide strand) to target relevant mRNAs at their 3'-untranslated regions. The functions of only a fraction of the identified miRNAs are known It appears that miRNAs play an essential role during development, since studies with Dicer knockout mice have shown that these die prematurely and have a variety of developmental abnormalities [5,6,7].

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Results

Conclusion