New breakthrough could help reverse receding hairlines

Researchers have described some of the factors that determine when hair grows, when it stops growing and when it falls out.

Authored by Krzysztof Kobielak, MD, PhD, postdoctoral fellow Eve Kandyba, PhD, and their colleagues, the three publications focus on stem cells located in hair follicles (hfSCs), which can regenerate hair follicles as well as skin.

These hfSCs are governed by the signaling pathways BMP and Wnt - which are groups of molecules that work together to control cell functions, including the cycles of hair growth.

The Kobielak lab first proposed Wnt7b's role in a January 2013 PNAS publication. The paper identified a complex network of genes - including the Wnt and BMP signaling pathways - controlling the cycles of hair growth.

Reduced BMP signaling and increased Wnt signaling activate hair growth. The inverse - increased BMP signaling and decreased Wnt signaling - keeps the hfSCs in a resting state.

A third paper published in Stem Cells in September 2013 further clarified the workings of the BMP signaling pathway by examining the function of two key proteins, called Smad1 and Smad5. These proteins transmit the signals necessary for regulating hair stem cells during new growth.

Kobielak said that collectively, these new discoveries advance basic science and, more importantly, might translate into novel therapeutics for various human diseases.

He said that since BMP signaling has a key regulatory role in maintaining the stability of different types of adult stem cell populations, the implication for future therapies might be potentially much broader than baldness - and could include skin regeneration for burn patients and skin cancer.

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