Pimecrolimus interferes the therapeutic efficacy of human mesenchymal stem cells in atopic dermatitis by regulating NFAT-COX2 signaling

The study found that pimecrolimus, a calcineurin inhibitor used for atopic dermatitis (AD), reduced the therapeutic efficacy of human umbilical cord blood-derived mesenchymal stem cells (hUCB-MSCs) in a mouse model. Pimecrolimus interfered with the stem cells' ability to modulate immune responses by inhibiting the nuclear translocation of NFAT3, crucial for COX2-mediated immunomodulation. This disruption affected the reduction of epidermal thickness and mast cell infiltration, key therapeutic effects of hUCB-MSCs. The findings highlighted the importance of considering drug interactions in MSC-based therapies for AD, as the combination therapy was less effective than hUCB-MSCs alone.