Article Summary by Michael Buontempo, MS4 | MD Candidate | Hackensack Meridian School of Medicine

Elevated levels of a protein called Dipeptidyl peptidase 4 (DPP4) have been linked to issues like halted hair growth and skin fibrosis, conditions often seen in alopecia.¹ To explore whether blocking this protein could improve hair growth, in the article “Repurposing DPP4-Inhibition to Improve Hair Follicle Activation and Regeneration”, Maria Helm et al. conducted a study using a drug named sitagliptin, which is an FDA-approved DPP4 inhibitor.¹

The study observed mice and human scalp tissues and found that higher DPP4 activity was particularly noticeable in the dormant or ‘rest’ phase of the hair growth cycle. This phase is called ‘telogen,’ and it’s when your hair isn’t growing but is just maintaining its position. Elevated DPP4 activity was also observed in areas of the skin that were non-regenerative, like wound peripheries.

The research team applied sitagliptin topically to the skin of mice. The results were promising—sitagliptin accelerated hair growth and reduced the markers that indicate skin fibrosis. It also boosted a pathway called Wnt signaling, which is crucial for hair growth. Researchers further carried out a single-cell RNA sequencing that demonstrated sitagliptin downregulated pathways that cause fibrosis while activating those related to hair growth.

So what does this mean for you? If you’re dealing with alopecia or skin fibrosis, sitagliptin could offer a new treatment avenue. It could work to not only promote hair growth but also to minimize fibrotic activity, making it potentially effective for both conditions.

In the study, sitagliptin didn’t kickstart the growth phase (anagen) on its own but did speed it up after the hair was depilated (shaved or removed). This also hints at the drug’s possible role in quicker wound healing and hair follicle regeneration.

In a nutshell, this research suggests that DPP4 inhibitors like sitagliptin could be repurposed to treat alopecia and skin fibrosis. It may work by shifting the balance in your skin from being pro-fibrotic to promoting hair growth and wound healing. Keep an eye out for further studies to validate these findings.

See full article here.

1. Helm M, Schmidt M, Del Duca E, et al. Repurposing DPP4 Inhibition to Improve Hair Follicle Activation and Regeneration. J Invest Dermatol. May 24 2023;doi:10.1016/j.jid.2023.04.027