Mini but mighty: micro RNAs in the pathobiology of periodontal disease.

Micro RNAs (mi RNAs) are a family of small, noncoding RNA molecules that negatively regulate protein expression either by inhibiting initiation of the translation of mRNA or by inducing the degradation of mRNA molecules. Accumulating evidence suggests that mi RNA-mediated repression of protein expression is of paramount importance in a broad range of physiologic and pathologic conditions. In particular, mi RNA-induced dysregulation of molecular processes involved in inflammatory pathways has been shown to contribute to the development of chronic inflammatory diseases. In this review, first of all we provide an overview of mi RNA biogenesis, the main mechanisms of action and the mi RNA profiling tools currently available. Then, we summarize the available evidence supporting a specific role for mi RNAs in the pathobiology of periodontitis. Based on a review of available data on the differential expression of mi RNAs in gingival tissues in states of periodontal health and disease, we address specific roles for mi RNAs in molecular and cellular pathways causally linked to periodontitis. Our review points to several lines of evidence suggesting the involvement of mi RNAs in periodontal tissue homeostasis and pathology. Although the intricate regulatory networks affected by mi RNA function are still incompletely mapped, further utilization of systems biology tools is expected to enhance our understanding of the pathobiology of periodontitis. [ABSTRACT FROM AUTHOR]