A Wnt signaling pathway is an intracellular signaling cascade that leads to the upregulation of gene expression of certain proteins.
When Wnt binds to a cellular receptor complex known as frizzled/LRP, an intracellular reaction will start that eventually leads to the upregulation of β-Catenin. β-Catenin will bind to an intranuclear protein (TCF), and as a result, DNA gets activated and proteins are produced.
This signaling pathway is especially important during the embryonic period since it promotes the growth and proliferation of different body tissues, and in particular, the cardiac tissue.
The Wnt signaling pathways have been repeatedly shown to play a significant role in the promotion of hair growth and hair follicle morphogenesis. This effect is believed to be mediated by its action on the dermal papilla (DP).
The mechanism of action is similar to that seen in other tissues; however, the proteins expressed are different in hair follicles.
In the case of the dermal papilla, a 2019 study stated:
The Wnt/β-catenin signaling is specifically involved in hair follicle morphogenesis, regeneration, and growth. β-catenin is expressed in the dermal papilla and promotes anagen induction and duration, as well as keratinocyte regulation and differentiation.
How to activate the Wnt signalling pathways in the scalp
There are a number of treatments currently being researched with the purpose of up-regulating the Wnt signalling pathways.
Samumed SM04554 is a hair loss treatment currently in clinical trials, which has shown some promising results: In the phase 2 trials, one treatment group showed a 10% increase in hair growth.
This treatment isn’t available to the public yet but the trials look promising and I suspect it will be available within five years.
The milk protein: lactoferrin
In one study, researchers concluded that topically applied lactoferrin protein “significantly promoted hair induction”. The researchers concluded that lactoferrin can keep hair follicles in the anagen (growth) phase for longer via activation of several Wnt signalling pathways.
The prostaglandin PGE2 is a Wnt activator. Several treatments have been shown to increase PGE2, including ricinoleic acid, Bimatoprost, Latanoprost and Sulfasalazine.