Baldness Breakthrough: microRNA Stimulates Hair Growth in Aging Follicles

By Northwestern UniversityJune 8, 2023

Northwestern Medicine scientists found that the stiffness of aging hair follicle stem cells hinders hair growth. They discovered that softening these cells using a tiny RNA, miR-205, stimulates hair growth in mice. Future experiments will test whether topically delivered miR-205 can promote hair growth potentially in humans.

Softening stiff hair follicle stem cells with a microRNA regrows hair.

Just as people's joints can get stiff as they age and make it harder for them to move around, hair follicle stem cells also get stiff, making it harder for them to grow hair, reports a new Northwestern Medicine study.

But if the hair follicle's stem cells are softened, they are more likely to produce hair, the scientists found.

Northwestern scientists discovered how to soften up those stem cells to enable them to grow hair again. In a study in mice published recently in the journal PNAS, the investigators report that they can soften the stem cells by boosting the production of a tiny RNARibonucleic acid (RNA) is a polymeric molecule similar to DNA that is essential in various biological roles in coding, decoding, regulation and expression of genes. Both are nucleic acids, but unlike DNA, RNA is single-stranded. An RNA strand has a backbone made of alternating sugar (ribose) and phosphate groups. Attached to each sugar is one of four bases—adenine (A), uracil (U), cytosine (C), or guanine (G). Different types of RNA exist in the cell: messenger RNA (mRNA), ribosomal RNA (rRNA), and transfer RNA (tRNA)." data-gt-translate-attributes="[{"attribute":"data-cmtooltip", "format":"html"}]">RNA, miR-205, that relaxes the hardness of the cells. When scientists genetically manipulated the stem cells to produce more miR-205, it promoted hair growth in young and old mice.

"They started to grow hair in 10 days," said corresponding author Rui Yi, the Paul E. Steiner Research Professor of Pathology and professor of dermatology at Northwestern UniversityEstablished in 1851, Northwestern University (NU) is a private research university based in Evanston, Illinois, United States. Northwestern is known for its McCormick School of Engineering and Applied Science, Kellogg School of Management, Feinberg School of Medicine, Pritzker School of Law, Bienen School of Music, and Medill School of Journalism. " data-gt-translate-attributes="[{"attribute":"data-cmtooltip", "format":"html"}]">Northwestern University Feinberg School of Medicine. "These are not new stem cells being generated. We are stimulating the existing stem cells to grow hair. A lot of times we still have stem cells, but they may not be able to generate the hair.

"Our study demonstrates the possibility of stimulating hair growth by regulating cell mechanics. Because of the potential to deliver microRNA by nanoparticles directly into the skin, next we will test whether topically delivered miR-205 can stimulate hair growth first in mice. If successful, we will design experiments to test whether this microRNA can promote hair growth potentially in humans."

This study was conducted in genetically engineered mouse models. The scientists used advanced microscopy tools, including atomic force microscopy, to measure the stiffness and two-photonA photon is a particle of light. It is the basic unit of light and other electromagnetic radiation, and is responsible for the electromagnetic force, one of the four fundamental forces of nature. Photons have no mass, but they do have energy and momentum. They travel at the speed of light in a vacuum, and can have different wavelengths, which correspond to different colors of light. Photons can also have different energies, which correspond to different frequencies of light." data-gt-translate-attributes="[{"attribute":"data-cmtooltip", "format":"html"}]">photon microscopy to monitor cell behaviors in live animals.

Reference: "MicroRNA-205 promotes hair regeneration by modulating mechanical properties of hair follicle stem cells" by Jingjing Wang, Yuheng Fu, Wenmao Huang, Ritusree Biswas, Avinanda Banerjee, Joshua A. Broussard, Zhihai Zhao, Dongmei Wang, Glen Bjerke, Srikala Raghavan, Jie Yan, Kathleen J. Green and Rui Yi, 22 May 2023, Proceedings of the National Academy of Sciences.DOI: 10.1073/pnas.2220635120

Other Northwestern authors include Jingjing Wang, Yuheng Fu, and Kathleen Green.

This study was funded by the National Institute of Arthritis and Musculoskeletal and Skin Diseases grants AR066703, AR071435, AR043380, AR041836, and P30AR075049 of the National Institutes of HealthThe National Institutes of Health (NIH) is the primary agency of the United States government responsible for biomedical and public health research. Founded in 1887, it is a part of the U.S. Department of Health and Human Services. The NIH conducts its own scientific research through its Intramural Research Program (IRP) and provides major biomedical research funding to non-NIH research facilities through its Extramural Research Program. With 27 different institutes and centers under its umbrella, the NIH covers a broad spectrum of health-related research, including specific diseases, population health, clinical research, and fundamental biological processes. Its mission is to seek fundamental knowledge about the nature and behavior of living systems and the application of that knowledge to enhance health, lengthen life, and reduce illness and disability." data-gt-translate-attributes="[{"attribute":"data-cmtooltip", "format":"html"}]">National Institutes of Health.