Plasma levels of matrix metalloproteinases in early psychosis, anxiety and depression: Evidence from the ALSPAC cohort.

Background: Converging evidence supports the role of Matrix Metalloproteinases (MMPs) in psychiatric disorders. Originally identified as regulators of the extracellular matrix (ECM), MMPs' functions span multiple processes, including inflammation, synaptic plasticity, neuronal migration, and blood-brain barrier maintenance. Tissue Inhibitors of Metalloproteinases (TIMPs) are major regulators of MMPs. In the present study we examined the associations of plasma MMPs and TIMPs with mental disorders in young adults aged 24 years in the Avon Longitudinal Study of Parents and Children (ALSPAC).

Methods: The present study was a nested case control study within the Avon Longitudinal Study of Parents and Children and comprised 374 participants who met criteria for psychiatric disorders (35 met the criteria for psychotic disorder, 201 for mild/moderate depressive disorder, and 266 for generalised anxiety disorder) and 401 controls. All cases and controls had were selected from the group of 4019 participants who had attended at age 24 years, completed psychiatric assessments and provided plasma samples. Plasma concentrations of MMP2, MMP3, MMP9 and TIMP-4 were quantified using proximity extension assays available on Olink® Cardiovascular Panel III. Logistic regression analysis compared standardised MMPs and TIMPs levels in cases and controls. Models were adjusted for sex, body mass index, and cigarette smoking.

Results: There was evidence for an association between MMP3 and depressive disorder (Odds ratio [OR] 1.35, 95 % confidence interval [CI] 1.06-1.73). There was evidence for an association between TIMP4 and depressive disorder (OR 1.51, 95 % CI 1.22-1.88) and generalised anxiety disorder (OR 1.43, 95 % CI 1.19-1.72). There was no evidence for an association between MMPs and psychotic disorders.

Conclusions: The study revealed that 24-year-olds with depressive and anxiety disorders exhibited elevated plasma concentrations of TIMP-4 compared to controls. There was evidence for an association between MMP3 and depressive disorder. These findings provide further support for the involvement of metalloproteinases as biomarkers in the pathophysiology of mental disorders during early adulthood.