A new study published in the Proceedings of the National Academy of Sciences (PNAS) has highlighted an unexpected link between pigmentation genetics and impaired wound repair, identifying the melanocortin-1 receptor (MC1R) pathway as a potential therapeutic target for chronic wounds.
From pigment to repair: Why MC1R matters
Though MC1R is most famous for influencing hair colour – with certain ‘red-hair variants’ leading to fair skin and ginger hair – it is also expressed in a wide range of skin cells, including immune cells, keratinocytes, fibroblasts and vascular cells.
According to the PNAS study, chronic wounds, such as diabetic foot ulcers, venous leg ulcers or pressure ulcers, share a common feature: the signalling axis involving MC1R and its natural ligand (part of the POMC‑MC1R axis) is functionally impaired.
When MC1R signalling is compromised, the critical transition from inflammation to tissue repair becomes disrupted. Immune cells linger, inflammation continues unchecked and healing stalls.
Mouse models reveal therapeutic potential
To explore whether restoring MC1R activity could correct the problem, the research team developed a reproducible mouse model meant to mimic human chronic wound conditions — combining factors such as advanced age and oxidative stress that often impair healing in humans.
In ‘red-fur’ mice carrying non-functional MC1R (analogous to human variants linked to red hair), wounds healed slowly: after seven days, only 73 percent of the lesion had closed, compared with 93 percent in ‘black-fur’ mice with functional MC1R.
The researchers then evaluated whether pharmacological stimulation of MC1R could improve healing. A topical cream containing an MC1R-selective agonist accelerated wound closure in mice with intact receptor function. The study reports improvements in vascularisation, reduced inflammatory exudate and more orderly tissue repair.
However, as noted in the paper, the treatment effect depended on the presence of at least partially functional MC1R. In mice lacking functional receptor activity, the topical agonist did not reverse the delayed healing phenotype.
Implications for chronic wound care
The authors suggest that MC1R may play a more significant role in wound biology than previously understood, particularly in the resolution of inflammation and progression to tissue regeneration.
While the findings point towards a possible new therapeutic pathway for chronic wound management, the researchers emphasise that these results are preclinical and human trials will be required to determine whether MC1R-targeted treatments could translate into clinical practice.
Nevertheless, the findings suggest that MC1R activation could play a key role in new wound-care treatments, particularly topical gels or ointments that patients or clinicians could apply directly.
