MicroRNAs (miRNAs) are non-coding RNAs that negatively regulate translation and are involved in multiple cellular processes. A large portion of circulating miRNAs are contained in exosomes. Dr. Kahn and colleagues demonstrated that adipose tissue is an important source of circulating miRNAs by showing that mice with an adipose-tissue-specific knockout of the miRNA processing enzyme Dicer have a significantly decreased number of circulating exosomal miRNAs. Further, fat transplantation from normal mice into mice with fat-specific Dicer knockout restores normal levels of circulating miRNAs. Humans with decreased fat due to lipodystrophy – both HIV-associated and congenital generalized lipodystrophy – also demonstrate significant reductions in circulating miRNAs.
Adipose tissue is an important source of circulating exosomal miRNAs, which can act as adipokines to regulate gene expression in distant tissues.
- Thomou T, Mori MA, Dreyfuss JM, Konishi M, Sakaguchi M, Wolfrum C, Rao TN, Winnay JN, Garcia-Martin R, Grinspoon SK, Gorden P, Kahn CR. Adipose-derived circulating miRNAs regulate gene expression in other tissues. Nature. 2017. Epub ahead of print: Feb 15 doi: 10.1038/nature21365.
Read More: Nature
- Research Center: Harvard Medical School
- Featured NORC Member(s): Steven Grinspoon, MD, NORCH Director, Professor of Medicine, Harvard Medical School; C. Ronald Kahn, MD, Mary K. Iacocca Professor of Medicine, Harvard Medical School
- Center Contribution: Dr. Grinspoon is the Director of the NORCH.