New animal research has described a microRNA, which appears to modulate hair growth.
The study, which appears in the Science Advances journal, may lay the groundwork for future hair regrowth treatments that are more effective and less invasive than the options currently available.
Loss of hair is commonly associated with aging. Yet it may also be attributed to hormonal changes, environmental and genetic influences as well.
Minoxidil and finasteride may be main hair loss therapies. While both therapies have been approved by the Food and Drug Administration ( FDA), both are especially successful, and both require regular re-application.
As the authors of the present study state, “Both are built not for the treatment of hair loss but for serendipity.”
As a result , scientists are finding new ways to accelerate hair regrowth. Work usually focuses on encouraging hair follicles — certain parts of the skin that develop hair — to switch from a state of rest to an active state.
Instead of transplanting hair follicles which can be expensive and dependent on a ready donor supply, more recent research has tried to stimulate hair follicle cells in the laboratory. Instead scientists add those cells directly to the balding region of the scalp.
However, research has shown that the hair follicle cells require cultures in the right conditions for this to be successful in stimulating growth. These conditions involve a 3D sphere.
To shift the hair follicle from a passive to an active state, the hair follicle cells need to interact with other cells. In a 3D environment, rather than a flat 2D environment, they do it better.
3D cultured cells
The researchers started by corroborating this earlier work in the present analysis. They achieved so by treating mice in a keratin scaffold with 2D cultured follicle cells, 3D cultivated follicle cells, and minoxidil.
We observed, as with previous studies, that the 3D cultured follicle cells transplanted onto the baldness areas were more successful than either the 2D cultured follicle cells or the minoxidil. The mice that received treatment with the 3D cultured follicle cells recovered 90 per cent of their hair after 15 days.
Dr. Ke Cheng, professor at the Department of Molecular Biomedical Sciences at the College of Veterinary Medicine, North Carolina State University, Raleigh, and research leader, states, “The 3D cells in a keratin scaffold performed best, as the spheroid mimics the hair microenvironment, and the keratin scaffold acts as an anchor to keep it where it is needed.”
“But we were also interested in how [dermal papillae] cells control the process of follicle formation, so we looked at the exosomes, namely exosomal [microRNAs] from that microenvironment.”
The dermal papillae (DP) cells help regulate the activity of hair follicles. MicroRNAs are molecules which help to regulate how genes communicate. They ‘re enclosed in small sacs, called exosomes.
The researchers looked at the exosomes of both the 2D and 3D cultured cell follicles. They noticed that the microRNA miR-218-5p encouraged gene communication which signaled hair growth in the 3D cultured cell follicles.
He confirmed this when he found that growing microRNA increased the development of hair follicles while inhibiting it prevented the hair follicle from functioning.
The team’s discovery is potentially useful, because while 3D cultured cell follicle implantation is successful in stimulating hair follicle growth, the transplantation process is laborious and expensive.
“Cell therapy with the 3D cells could be an effective treatment for baldness, but you have to grow, expand, preserve, and inject those cells into the area. [MicroRNAs], on the other hand, can be utilized in small molecule-based drugs. So potentially, you could create a cream or lotion that has a similar effect with many fewer problems. Future studies will focus on using just this [microRNA] to promote hair growth.”– Dr. Cheng