Does this trunk make me look fat? Overweight zoo elephants no laughing matter

Date:

July 13, 2014

Source:

University of Alabama at Birmingham

Summary:

The birthrate for African elephants in zoos is declining, and researchers look for a link between inflammation and obesity that may be connected to the increase in infertility. "Obesity affects about 40 percent of African elephants in captivity," said one researcher. "Much as we see in humans, excess fat in elephants contributes to the development of heart disease, arthritis, a shorter lifespan and infertility."

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Obesity Reversed in Mice by Manipulating Production of an Enzyme

ScienceDaily (Dec. 5, 2012) — Approximately 68 percent of U.S. adults are overweight or obese, according to the National Cancer Institute, which puts them at greater risk for developing cancer, cardiovascular disease, diabetes and a host of other chronic illnesses. But an international team of scientists led by Virginia Commonwealth University Massey Cancer Center researcher Andrew Larner, M.D., Ph.D., has successfully reversed obesity in mice by manipulating the production of an enzyme known as tyrosine-protein kinase-2 (Tyk2). In their experiments, the scientists discovered that Tyk2 helps regulate obesity in mice and humans through the differentiation of a type of fat tissue known as brown adipose tissue (BAT).

Published December 5 in the online edition of the journal Cell Metabolism, the study is the first to provide evidence of the relationship between Tyk2 and BAT. Previous studies by Larner and his team discovered that Tyk2 helps suppress the growth and metastasis of breast cancer, and now the current study suggests this same enzyme could help protect against and even reverse obesity.

The scientists were able to reverse obesity in mice that do not express Tyk2 by expressing a protein known as signal transducer and activator of transcription-3 (Stat3). Stat3 mediates the expression of a variety of genes that regulate a host of cellular processes. The researchers found that Stat3 formed a complex with a protein known as PR domain containing 16 (PRDM16) to restore the development of BAT and decrease obesity.

Continued:  http://www.sciencedaily.com/releases/2012/12/121205132433.htm

Could High Insulin Make You Fat? Mouse Study Says Yes

ScienceDaily (Dec. 4, 2012) — When we eat too much, obesity may develop as a result of chronically high insulin levels, not the other way around. That's according to new evidence in mice reported in the December 4th Cell Metabolism, a Cell Press publication, which challenges the widespread view that rising insulin is a secondary consequence of obesity and insulin resistance.

The new study helps to solve this chicken-or-the-egg dilemma by showing that animals with persistently lower insulin stay trim even as they indulge themselves on a high-fat, all-you-can-eat buffet. The findings come as some of the first direct evidence in mammals that circulating insulin itself drives obesity, the researchers say.

The results are also consistent with clinical studies showing that long-term insulin use by people with diabetes tends to come with weight gain, says James Johnson of the University of British Columbia.

"We are very inclined to think of insulin as either good or bad, but it's neither," Johnson said. "This doesn't mean anyone should stop taking insulin; there are nuances and ranges at which insulin levels are optimal."

Continued:  http://www.sciencedaily.com/releases/2012/12/121204145549.htm