Melanopsin and rhodopsin mediate UVA-induced immediate pigment darkening: Unravelling the photosensitive system of the skin.

摘要: Abstract The mammalian skin has a photosensitive system comprised by several opsins, including rhodopsin (OPN2) and melanopsin (OPN4). Recently, our group showed that UVA (4.4 kJ/m2) leads to immediate pigment darkening (IPD) in murine normal malignant melanocytes. We show the role of OPN2 OPN4 as sensors: UVA-induced IPD was fully abolished when pharmacologically inhibited AA9253 or were knocked down siRNA both cell lines. Our data, however, demonstrate phospholipase C/protein kinase C pathway, classical is not involved either line. Nonetheless, types we have shown that: a) intracellular calcium signal necessary for IPD; b) involvement CaMK II, whose inhibition, c) CAMK II/NOS/sGC/cGMP pathway process since inhibition NOS sGC IPD. Taken altogether, participate induced melanocytes through conserved common pathway. Interestingly, upon knockdown OPN4, UVA-driven completely lost, which suggests opsins are required cooperatively participation radiation-induced response, if proven take place human skin, may represent an interesting pharmacological target treatment depigmentary disorders skin-related cancer.