Blood assessment of the expression levels of matrix metalloproteinase 9 (MMP9) and its natural inhibitor, TIMP1 genes in Iranian schizophrenic patients

Schizophrenia (SCZ) is the most severe chronic mental disorder characterized by abnormal social behavior and disrupted emotions and thought. Like other complex neuropsychological disease, SCZ is caused by a combination of genetic and environmental factors but with a high concordance rate. So far, different genetic factors are revealed to be associated with increased risk of developing SCZ. One of the best ways to investigate the genetic basis of the complex disease is to discover the genetic underlying mechanisms of the defective clinical aspects of the patients. In this regard, genes involved in the developmental mechanisms of the brain such as long-term potentiation (LTP) process that is the basis of synaptic plasticity, memory and learning are considered as strong candidates for SCZ. The aim of the present study was to evaluate the expression levels of two genes that are involved in the LTP regulation in the developing and adult brain, Matrix metallopeptidase9 (MMP9) and TIMP metallopeptidase inhibitor 1 (TIMP1) genes in a blood assessment of schizophrenic patients in comparison to healthy controls by means of quantitative real time PCR. The results of the study showed a significant difference in MMP9/TIPM1 ratio between SCZ patients and healthy controls (P = 0.01). However, no significant difference was detected in the expression level of individual MMP9 and TIMP1 genes in SCZ patients versus healthy controls either in total numbers of subject or in sex based subgroups. Considering the relatively small sample size of the current study, there is a need to replicate this study with further investigations about the mechanism of association of these genes and their functions in the pathogenesis of the SCZ.