Relationship between matrix metalloproteinase-9 and oxidative stress in drug-free male schizophrenia: a case control study

Abstract

BACKGROUND: Deregulation of synaptic plasticity and oxidative stress are reported to play a crucial role in the pathogenesis of schizophrenia. Matrix metalloproteinase-9 (MMP-9) is an extracellular protease involved in regulation of synaptic plasticity. Malondialdehyde (MDA) is a marker of lipid peroxidation which is elevated in schizophrenia. Earlier studies have reported polymorphism of MMP-9 and its association with schizophrenia. The present study was designed to assess the serum levels of MMP-9, MDA and total antioxidant status (TAS) and their association in schizophrenia. METHODS: A total of 40 cases and 40 controls were included in the study. Serum MMP-9, MDA and TAS were estimated in all the subjects. Disease severity was assessed using Positive and Negative Syndrome Scale (PANSS). RESULTS: MMP-9 and MDA were significantly increased and TAS were significantly reduced in schizophrenia cases compared to controls. MMP-9 was positively correlated with MDA (r=0.353, p=0.025) and negatively correlated with TAS (r=-0.461, p=0.003). TAS was significantly correlated with total (r=0.322, p=0.043) and negative symptom scores (r=0.336, p=0.034). Higher MMP-9 levels were associated with previous exposure to antipsychotics (p=0.032). CONCLUSIONS: MMP-9 and oxidative stress were increased and correlate well with each other in schizophrenia cases. Though total oxidant status showed positive association with disease severity, MMP-9 and MDA were not associated with the severity of the disease.