The expression of genes encoding for COX-2, MPO, iNOS, and sPLA2-IIA in patients with recurrent depressive disorder.

Background: There is evidence that inflammation, oxidative and nitrosative stress (IO&NS) play a role in the pathophysiology of depression. There are also data indicating altered inflammatory gene expression in depressive disorder and that genetic variants of IO&NS genes are associated with increased risk of the disease in question. The aim of this study was to explore mRNA expression of four IO&NS genes PTGS2, MPO, NOS2A, and PLA2G2A coding respectively: cyclooxygenase-2 (COX-2), myeloperoxidase (MPO), inducible nitric oxide synthase (iNOS) and secretory phospholipase A2 type IIA (sPLA2-IIA).

Method: Expression of the mRNA was determined using quantitative real-time PCR, in peripheral blood cells of patients with recurrent depressive disorder (rDD) and normal controls.

Results: The mRNA expressions of the genes encoding for COX-2, MPO, iNOS and sPLA2-IIA were significantly increased in the peripheral blood cells of depressed patients versus controls.

Limitations: Patients were treated with antidepressants.

Conclusion: Our results indicate and may confirm the role of peripheral IO&NS pathways in the pathophysiology of depression. The results represent a promising way to investigate biological markers of depression.