A new study has revealed an unexpected mechanism for the development of vitiligo, which could radically change the way we deal with this autoimmune skin disease.
Instead of the pigment cells responsible for skin color dying completely, as was previously believed, it turns out that they enter a state similar to "hibernation" or regression to a primitive form, which opens up new prospects for future treatments that reactivate them.
Vitiligo is an autoimmune disease in which the immune system attacks melanocytes (pigment-producing cells) that produce melanin, the pigment responsible for skin color, resulting in characteristic white patches on the skin. However, the traditional model of the disease has always faced a paradox: how do some vitiligo lesions regain pigmentation spontaneously? And how do treatments restore pigmentation in areas that appear completely devoid of pigment cells?
This contradiction prompted a team from Osaka Metropolitan University, led by Professor Ichiro Katayama and Professor Lingli Yang, to investigate further, discovering that pigment cells do not disappear completely, but rather enter a "dedifferentiation-like state," meaning they revert to a more primitive form and lose their ability to produce pigment and other specialized functions, but they remain present in the skin.
This discovery is based on understanding the relationship between pigment cells and the basement membrane, the thin layer that separates the epidermis from the dermis, and provides pigment cells with physical and chemical signals that help them maintain their function as pigment-producing cells.
Under normal conditions, melanocytes bind to a protein called laminin-211 via specific receptors. However, in patients with vitiligo, a fundamental change occurs in the basement membrane, which becomes rich in another protein, laminin-332. This change forces melanocytes to alter their binding mechanism, abandoning their preferred binding factor (dystrglycan) and relying on another factor (α3β1 integrin).
This shift in binding activates cellular pathways that lead to reorganization of cell structure and altered gene expression, causing cells to regress to an immature, primitive state, losing their ability to produce pigment and maintain an intact basement membrane. Even more concerning is that this regression creates a vicious cycle: the more cells regress to their primitive state, the less able they become to maintain a healthy basement membrane, which reinforces the changes that lead to further regression, perpetuating the cycle.
The team's most exciting discovery was that these genetic changes are not permanent. When the researchers used drug inhibitors targeting the molecular pathways activated by this linkage shift, they were able to restore melanocyte function, reinstate maturation markers, restore gene expression associated with pigment production, and reverse many features of the primitive state.
Professor Lingli Yang commented: "This suggests that the change in gene expression is not permanent, and that this process may be reversible. We found that the drugs were able to restore melanocyte function and pigment-related properties. The next step will be to conduct clinical studies to see if this approach is a viable way to manage the disease."
Professor Ichiro Katayama added: "This was an exciting discovery for us, as most current treatments focus heavily on suppressing autoimmune attacks and reducing inflammation, but if dormant pigment cells are still present in the lesions, it could change the way we treat the disease. New therapeutic approaches may become possible, such as reactivating existing cells or restoring their normal attachment to the basement membrane."
