In contrast, IFN-γ stimulation in monocytes previously exposed to psoriasis' sera increased MMP-9 levels and decreased TIMP-1 levels, whereas stimulation in monocytes exposed to non-psoriatic sera did not further modify the levels of MMP-9 or TIMP-1.
To investigate the role of stromelysins-1 and -2, matrilysin, metalloelastase, collagenases-1 and -3 and 92-kDa gelatinase as well as their inhibitors, TIMPs-1 and -3, in psoriasis, we performed in situ hybridization using 35S-labeled cRNA probes on 29 psoriatic lesions and 9 samples of normal looking skin from psoriatic patients.