Fat tissue can communicate with other organs | National Institutes of Health (NIH) – by Tianna Hicklin, Ph.D. – Feb 2017
I’m posting this because it upends the common belief that fat is inert. We usually view fat as an unnecessary and monolithic “blob” to be pared down as much as we can, but here we see it’s much more complicated than that.
At a Glance
- Researchers discovered that fat tissue releases signals called microRNAs into the bloodstream that regulate genes in another organ.
- The findings suggest new ways to treat metabolism-related diseases like obesity and diabetes.
Fat tissue helps your body store excess energy. It also releases hormones and other substances that help regulate your body’s metabolism by communicating with other organs and tissues, such as your liver, pancreas, and muscles.
Mammals, including people, have 2 main types of fat: white and brown.
- Most body fat is white fat, which stores extra energy that can then be used when needed—for example, when exercising.
- Whereas brown fat burns energy to help regulate body temperature.
Several cell types, including fat cells, make small pieces of genetic material, called microRNAs.The precise roles of microRNAs are currently under intense investigation.
High levels of certain microRNAs have shown to correlate with the presence of several diseases, including cancer, diabetes, heart disease, and obesity.
The amount of microRNA in white fat tissue is known to decline with age. This is due to lower levels of an enzyme that processes microRNAs called Dicer.
Removing the Dicer gene from fat cells prevented the cells from making microRNAs.
Animals missing the enzyme in their fat cells
- had less white fat than control mice. They also
- had brown fat with altered properties and
- were insulin resistant.
Most microRNAs are found in tiny, fluid-filled sacs called exosomes.
The scientists next investigated whether microRNAs released by fat tissue could affect other tissues. Through a series of experiments, they showed that circulating exosomal microRNAs from one mouse could regulate gene expression in the liver of another.
Related Links [from the NIH -zyp]
- Insights into Energy-Burning Fat Cell
- Drug Activates Brown Fat and Increases Metabolism
- Cool Temperature Alters Human Fat and Metabolism
- Minding Your Metabolism: Can You Avoid Middle-Age Spread?
- Weight-Loss and Nutrition Myths
References: Adipose-derived circulating miRNAs regulate gene expression in other 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. Nature. 2017 Feb
For more information, here’s a free full-text /PMC4504744/ that explains MicroRNAs:
The discovery of the first microRNA (miRNA) over 20 years ago has ushered in a new era in molecular biology.
There are now over 2000 miRNAs that have been discovered in humans and it is believed that they collectively regulate one third of the genes in the genome.
miRNAs have been linked to many human diseases and are being pursued as clinical diagnostics and as therapeutic targets.
This review presents an overview of the miRNA pathway, including biogenesis routes, biological roles, and clinical approaches.