Study Report

CitationZhang, 2015 PubMed
Full InfoZhang, Y., Chang, Z., Chen, J., Ling, Y., Liu, X., Feng, Z. ... Zhang, C. (2015). Methylation of the tryptophan hydroxylase?2 gene is associated with mRNA expression in patients with major depression with suicide attempts. Molecular Medicine Reports, 12, 3184-3190.

Hypothesis or Background Tryptophan hydroxylase-2 (TPH2) contributes to alterations in the function of neuronal serotonin (5-HT), which are associated with various psychopathologies, including major depressive disorder (MDD) or suicidal behavior.
Sample Information50 patients with MDD
Method Detail The aim of the present study was to investigate whether variations in TPH2 methylation in peripheral blood samples may predispose patients with MDD to suicide attempts.
Method Keywordsperipheral blood
ResultTPH2 mRNA expression levels differed significantly between 50 patients with MDD who had attempted suicide (MDD + suicide group) and 75 control patients with MDD (MDD group); TPH2 expression levels were significantly decreased (P=0.0005) in the patients who had attempted suicide. Furthermore, the frequency of TPH2 methylation was 36.0% in the MDD + suicide group, while it was 13.0% in the MDD group. In addition, there was a significant correlation between the methylation status of the TPH2 promoter and depression, hopelessness and cognitive impairment in the MDD + suicide group.
Conclusions The results of the present study demonstrated that methylation in the promoter region of TPH2 significantly affected the mRNA expression levels of TPH2, thus suggesting that methylation of the TPH2 promoter may silence TPH2 mRNA expression in MDD patients with or without suicidal behavior. In conclusion, the present study demonstrated that TPH2 expression was regulated by DNA methylation of the TPH2 promoter region in patients with MDD.

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