Scientists Accidentally Discover Weight Loss Therapy After Mice Start Sweating Fat From Their Skin

  Accidental science is the best. One of the greatest lifesaving drugs in history – penicillin – was discovered purely by accident, and such experiments truly show how intricate and unpredictable science is. 

So, when researchers from the University of Pennsylvania began their journey looking for a type 2 diabetes treatment and stumbled across a potentially incredible weight-loss treatment, needless to say, they were more than surprised. 

The researchers describe their new results in a paper in the journal Science, in which they applied a treatment to a group of lab mice in the pursuit of counteracting type 2 diabetes. Instead of performing as expected, the experiment took a surprising turn – the mice started secreting a slimy substance through their skin.  

“They glistened in the light,” said senior author and associate professor at the University of Pennsylvania Taku Kambayashi, in an interview with Inverse. 

“The ones that got TSLP [the treatment] they're always shiny, and I didn’t know what that meant.” 

“When they were losing that much weight, they were, I would say, slimy, almost,” he says. 

This substance completely surrounded the animals, and when the researchers analyzed it, they discovered it was actually fat. The treatment had made the mice shed fat directly through their skin. 

The treatment in question is thymic stromal lymphopoietin (TSLP). TLSP is a cytokine (small proteins that control immune cell activity) that has been shown previously to activate immune cells that control inflammation, a pathway vital for preventing type 2 diabetes and obesity. The researchers hypothesized that if the TSLP could hitch a ride into the body using a virus vector, they could stimulate the immune system into counteracting the disease. 

In this pursuit, they packaged the TSLP with an adenovirus vector, a method currently seen in many different experimental therapies. When injected into the mice, the TSLP caused them to rapidly shed weight through the secretion of sebum. Sebum is an oily substance that is produced by glands in the skin and contains lots of lipids, including oils and fat, that help defend the skin from bacteria and fungi. The TSLP had caused immune T cells to migrate to the glands that secrete sebum, causing them to secrete far more sebum and essentially ‘sweat’ out white adipose tissue (a common form of fat). 

Throughout the study, the mice lost around half of their entire white adipose tissue, including an especially nasty form of fat, visceral fat, which coats the organs and is strongly linked to mortality. 

The implications of this accidental discovery could be huge. A reliable weight loss method is sorely needed, as the world continues to struggle with rising obesity rates. Alongside the weight benefits, a TSLP-based therapy could be helpful in helping skin conditions such as eczema. Of course, the study only puts forward a potential avenue of research – far more safety, efficacy, and human trials would be needed before it could see widespread use. The researchers now aim to identify the mechanism behind the sebum production, as well as attempt to translate it into an effective therapy.