Increased serotonin 2C receptor mRNA editing: a possible risk factor for suicide

Area of Science:

• Neuroscience
• Psychiatry
• Genetics

Background:

• Suicide is a significant global public health issue, often associated with psychiatric disorders.
• The serotonin 2C receptor (5-HT 2C R) is implicated in depression and suicide, but its specific role in suicidal behavior requires further clarification.

Purpose of the Study:

• To investigate whether biological substrates of suicide are distinct from those of psychiatric disorders.
• To compare the frequencies of serotonin 2C receptor (5-HT 2C R) mRNA editing variants in individuals who died by suicide versus those who died from other causes, particularly within the context of schizophrenia (SZ) and bipolar disorder (BPD).

Main Methods:

• Analysis of postmortem prefrontal cortical specimens from suicide victims and control groups.
• Comparison of 5-HT 2C R mRNA editing variant frequencies between suicide and non-suicide cases, controlling for psychiatric diagnoses and demographic factors.

Main Results:

• Identified specific 5-HT 2C R mRNA editing variations associated with suicide, independent of comorbid SZ or BPD diagnoses.
• Observed a significant increase in mRNA variants (ACD and ABCD) encoding the low-activity VSV isoform of 5-HT 2C R in suicide cases.
• These variations were not influenced by age, sex, or substance use.

Conclusions:

• The identified 5-HT 2C R mRNA editing variations may represent a biological risk factor for suicidal behavior in patients with SZ or BPD.
• Overexpression of the low-functional VSV isoform of 5-HT 2C R in the prefrontal cortex could impact serotonergic regulation and contribute to suicidal behavior.