Understanding the mechanics of fat cells

[James Marusek 5,244]

According to the internet:

Adipose tissue, or fat, is an anatomical term for loose connective tissue composed of adipocytes. Its main role is to store energy in the form of fat, although it also cushions and insulates the body.

Excess adipose tissue (fat cells) can lead to problematic changes in metabolism, blood sugar control and blood pressure. Recently scientist have been exploring the role of fat cells acts on the brain to signal satiety (hunger control).

More recently, researchers have been delving into the mechanisms that adipose tissue uses to affect other parts of the body. A recent report in the journal Nature investigates one possible source of such control. To describe the study we have to define a couple of terms:

microRNA (miRNA): small (19-22 nucleotides long) segments of RNA that do not code for Proteins. There are many different types of miRNAs in the circulation and in different tissues, and they have various functions in the body. In general, they act to prevent translation of mRNAs and thus decrease the production of the corresponding proteins.

Dicer: an enzyme found in adipose as well as other tissues that processes miRNAs — without it miRNAs aren't produced.

Led by Dr. C. Ronald Kahn of the Joslin Diabetes Center of Harvard University, researchers bred so-called 'knockout' mice that lacked the Dicer enzyme in adipose tissue specifically. These adipose-tissue-specific Dicer knockout (ADicerKO) mice did not produce the usual complement of miRNAs found in normal mice, showing that adipose tissue is responsible for making a large number of the circulating miRNAs. And this is important, because the presence of such miRNAs is associated with improvements in glucose tolerance and other beneficial metabolic changes.

Indeed, the ADicerKO mice exhibited a decrease in brown adipose tissue (the most metabolically active type), as well as an increase in insulin resistance. However, when both brown and white adipose tissue from normal mice was transplanted into the knockout mice, they began to produce the miRNAs, demonstrating the importance of the adipose tissue in circulating miRNA production.

In addition to their work with the mice, the investigators also compared miRNAs from patients with lipodystrophy [1] with those from control people. They found that the patients with lipodystrophy had lower levels of over 200 different miRNAs compared to the controls.

Thus, both the animal and human data suggest an important role for adipose tissue in the regulation of metabolism, and may indicate an important avenue for future research into the roles of Dicer and miRNAs in the obesity-linked derangement of blood pressure, blood glucose regulation and insulin resistance.

http://acsh.org/news/2017/03/02/when-fat-speaks-body-listens-10911

[Berry78 4,259]

Interesting! Thanks!