Johns Hopkins University School of Medicine investigators have discovered that laser treatments and the drug retinoic acid share a common molecular pathway that exhibits relevance for improving skin condition. The pathway, which lets the human skin cells sense loose RNA molecules, has also shown up in mice when they regenerate hair follicles.
With the recent study published in Nature Communications in June 2019, the team collected biopsies from 17 patients beings treated at The Johns Hopkins Hospital with conventional laser skin rejuvenation to selectively erase sunspot and wrinkles. With an average age of 55 and all-white, the treatments were performed on the patient’s faces and arms. The Johns Hopkins team collected skin biopsies prior to the laser treatment and a week after the procedure.
The Johns Hopkins preclinical team had known for decades that mice can regenerate hair follicles after a deep wound. The Johns Hopkins scientist, Luis Garza, MD, Ph.D., and his team wondered whether double-stranded RNA (dsRNA) also played a role in skin rejuvenation treatments such as laser therapy, microneedling, and facial abrasion, all of which involve temporary damage to skin cells. The team analyzed the expression levels of genes in each sample and discovered that genes involved in sensing dsRNA as well as genes involved in producing the skin’s natural retinoic acid were all expressed at higher levels after the laser treatment.
Thereafter they tested isolated human skin cells with loose dsRNA and found that the amount of retinoic acid inside the cells exponentially increased—ten-fold.
To strengthen and understand the connection the team looked at a protein toll-like receptor c3 (TLR3) senses dsRNA. When the team engineered mice to lack TLR3, the animals could no longer regenerate hair follicles post a wound.
Research Garza noted that the findings could lead to novel strategies to reduce wrinkles and sunspots by combining retinoic acid and laser treatments in new ways. He noted, “After a burn, humans don’t regenerate structures like hair follicles and sweat glands that used to be there.” Garza continued “It’s possible in light of these new findings that double-stranded RNA may be able to improve the appearance of burn scars.”
- National Institute of Arthritis and Musculoskeletal and Skin Diseases
- Department of Defense and CDMRPR
- Northrup Grumman Electronic Systems
- Maryland Stem Cell Research Fund
- Eunice Kennedy Shriver National School of Pharmacy Mass Spectrometry Center
Luis Garza, MD, Ph.D.