Sweat Glands Are A Source of Stem Cells for Healing Wounds

When I was a kid, I used to wish that I had no sweat glands. Sweating made me sticky, wet and miserable. Little did I now, that without sweat glands, my body would have quickly overheated to fatal levels. A new study now shows that sweat glands are also the source of healing for wounds.

Human skin contains millions of eccrine sweat glands. These glands are not connected to hair follicles and they function throughout our lives to regulate the temperature of the body. Sweat glands respond to elevated bodily temperatures by secreting a mixture of NaCl and water. The water cools the external bodily temperature and is used to secrete other unwanted molecules. This is the main reason our sweat can smell like the food we ate (garlic, onions, etc.).

A new study by from the University of Michigan Health System shows that sweat glands play a key role in providing cells for recovering skin wounds, such as scrapes, burns and ulcers. These results were recently published in the American Journal of Pathology.

“Skin ulcers – including those caused by diabetes or bed sores – and other non-healing wounds remain a tremendous burden on health services and communities around the world,” says lead author of this work, Laure Rittié, who is a research assistant professor of dermatology at the Univ. of Michigan Medical School. She continued, “Treating chronic wounds costs tens of billions of dollars annually in the U.S. alone, and this price tag just keeps rising. Something isn’t working.”

U of M researchers believe they have discovered one of the body’s most powerful secret healers.

“By identifying a key process of wound closure, we can examine drug therapies with a new target in mind: sweat glands, which are very under-studied,” Rittié says. “We’re hoping this will stimulate research in a promising, new direction.”

Previously, wound healing was thought to originate from cells that came from hair follicles and from intact skin at the edge of the wound. However, the findings from the U of M research group demonstrate that cells arise from beneath the wound, and suggest that human eccrine sweat glands are the source of an important reservoir of adult stem cells that can quickly be recruited to aid wound healing.

Rittié commented: “It may be surprising that it’s taken until now to discover the sweat glands’ vital role in wound repair. But there’s a good reason why these specific glands are under-studied – eccrine sweat glands are unique to humans and absent in the body skin of laboratory animals that are commonly used for wound healing research.” Rittié continued: “We have discovered that humans heal their skin in a very unique way, different from other mammals. The regenerative potential of sweat glands has been one of our body’s best-kept secrets. Our findings certainly advance our understanding of the normal healing process and will hopefully pave the way for designing better, targeted therapies.”