Investigation of the associations between cardiovascular risk and inflammatory processes in major depressive disorder

Objective: An association between cardiovascular diseases and depression is known for a long time. There are many hypotheses for the reasons of that association. One of them is that inflammation could mediate the relation between cardiovascular risk and depression. In this thesis, comparing depressive and healthy individuals in terms of biomolecules consisting of NLRP3 inflammasome and cardiovascular risk scores was aimed. It was hypothesized that depressive persons would present higher expressions of NLRP3 inflammasome and cardiovascular risk scores, and those would be positively correlated to the severity of depression. Methods: At Dokuz Eylül University Hospital Psychiatry Clinic, 58 patients who were diagnosed as major depressive disorder and rated 18 points or above according to 21 item Hamilton Depression Rating Scale and 58 healthy persons who had similar features for age and sex were included in the current study. To determine cardiovascular risk, 10-year Framingham Cardiovascular Risk Score based on body mass index was used. mRNA expressions of NLRP3, ASC, caspase-1 and NEK7 coding proteins was evaluated with quantitative PCR, plasma IL-1β levels were detected by ELISA. Results: Depressive patients showed higher expressions of NLRP3 (p=0,037) and ASC (p=0,002) compared to healthy persons. Higher expressions of NLRP3 (p=0,046), ASC (p=0,003) and NEK7 (p=0,011) were demonstrated to be related with increased likelihood of depression. Conclusion: NLRP3 inflammasome is believed to be involved in the pathogenesis of depression. Further studies with different population characteristics are required to understand the impact of cardiovascular risk on the relation of depression and NLRP3 inflammasome. Keywords: depression, NLRP3, inflammasome, NEK7, IL-1β, cardiovascular risk