Özet:

Background: In this study, we aimed to investigate the mRNA expression levels of ADAMTS9 and ADAMTS15 in peripheral blood mononuclear cells (PBMCs) of psoriasis (PsO) and psoriatic arthritis (PsA) patients and the effects of TNF-α/MAPK and IL-1β/NFkB signaling pathways on the regulation of the expression of these genes. Materials and Methods: 15 PsO and 15 PsA patients and 15 healthy individuals (control) were included in the study. After PBMCs were isolated from venous blood, ADAMTS9 and ADAMTS15 mRNA expression levels were measured by Real-Time Quantitative PCR (RT-qPCR). Results: It was found that ADAMTS9 mRNA expression in PBMCs did not change between groups, while the level of ADAMTS15 mRNA expression increased significantly in the PsA group compared to the control and PsO gro-ups. ADAMTS9 expression was observed not changed in the control and PsA groups in response to TNF-α stimula-tion, but decreased in the PsO group. However; TNF-α stimulation led to an increase in ADAMTS15 expression in the control group but did not change in the PsO and PsA groups. It has been revealed that the formation of TNF-α response and related changes in ADAMTS9 and ADAMTS15 expressions were regulated by MAP kinase genes (Erk1/2, p38 and JNK). ADAMTS9 expression was determined not affected by IL-1β stimulation, however; ADAMTS15 mRNA expression was decreased only in the PsA group. In addition, NFkB signaling molecule was involved in the formation of the IL-1β response and the regulation of ADAMTS15 expression. Conclusions: ADAMTS15 expression increased in PBMCs of PsA patients is regulated by the IL-1β/NFkB signaling pathway. An increase in ADAMTS15 mRNA expressin level may play a role in PsA pathogenesis. Furthermore, the expression level of ADAMTS15 has a potential to be used as an important biomarker in monitoring the risk of PsA development for PsO patients.