Micro-RNAs in transplant tolerance.

PURPOSE OF REVIEW: Micro-RNAs (miRNAs) are highly conserved small RNA molecules that have selective gene-regulatory functions. This posttranscriptional regulation by miRNAs is critical for many immunological processes. Many developments in establishing the biological role of miRNAs in solid organ transplantation have been generated in the last decade. Discoveries of immune regulation by miRNAs, resulting in graft prolongation and transplant tolerance, are rapidly advancing and are the subject of this review.

RECENT FINDINGS: Many elegant experimental studies have revealed intriguing associations between transplant tolerance and specific miRNA profiles. These findings have provided insight into the miRNAs critical for sustaining immune suppression, and have revealed common miRNA pathways that should be further investigated and/or targeted therapeutically. Further reports have strategized and corroborated different methods of manipulating miRNA expression for prolonging allograft survival, yielding promising preclinical evidence of the efficacy of miRNA-based therapies.

SUMMARY: The review covers these recent developments in miRNA research that can revolutionize how we implement diagnostics and prognostics and how we can strategize transplantation therapies.