The tough protein that builds our skin, hair, and nails may also play a surprising role in keeping inflammation in check. A new study has found that a specific form of keratin acts as a kind of brake on the immune system — and when that brake fails, inflammatory skin diseases can take hold.
Published in the journal Science Translational Medicine, the research focused on keratin 16, a protein already known to be mutated in a rare genetic disorder called pachyonychia congenita. In that condition, mutations disrupt the network of filaments that protect skin cells in high-friction areas like the soles of the feet. Walking or running causes cells to break down, triggering painful calluses, blisters, and chronic inflammation.
But the findings extend well beyond rare diseases. As Live Science reported, the researchers found that keratin 16 normally helps skin cells manage inflammatory responses. In people without genetic mutations, the body ramps up production of the protein when skin faces stressors. In chronic inflammatory conditions like psoriasis, the tissue continuously produces large amounts of it.
"Knowing that Keratin 16 acts as an inflammatory brake gives us a direct target for new treatments and diagnostics," said study first author Erez Cohen and senior author Pierre Coulombe, both of the University of Michigan, in a joint statement.
Wendy Bollag, a professor of physiology at Augusta University who was not involved in the study, explained that keratins function "like the steel cables or steel beams of the cell." Without that structural integrity, skin becomes prone to tears, allowing microorganisms to enter and trigger immune responses.
The discovery could open new avenues for treating not only pachyonychia congenita but also far more common conditions like psoriasis and eczema, which affect millions of people worldwide.
