Elevated concentration of N-CAM VASE isoforms in schizophrenia

Area of Science:

• Neuroscience
• Molecular Biology
• Psychiatry

Background:

• Neural cell adhesion molecule (N-CAM) plays a crucial role in CNS development and cellular organization.
• Previous studies indicated elevated N-CAM 120 kDa in cerebrospinal fluid (CSF) of patients with schizophrenia, bipolar disorder, and depression.
• The variable alternative spliced exon (VASE) is a specific sequence within the N-CAM protein.

Purpose of the Study:

• To investigate the levels of VASE in the CSF of patients diagnosed with schizophrenia, bipolar disorder, and unipolar depression.
• To determine if VASE levels differ between these patient groups and healthy controls.
• To explore the relationship between VASE concentration and clinical symptoms in schizophrenia.

Main Methods:

• Western immunoblotting was used to measure VASE-immunoreactive (VASE-ir) bands in CSF samples.
• CSF was collected from patients with schizophrenia (n=14), bipolar I (n=7), bipolar II (n=9), unipolar depression (n=17), and matched controls (n=37).
• Statistical analysis, including MANOVA, was performed on logarithmic transformations of VASE protein units.

Main Results:

• A significant increase in heavy (51%) and medium (45%) molecular weight VASE protein bands was observed in schizophrenia patients compared to controls (p=0.0008 and p=0.04, respectively).
• No significant increase in VASE levels was found in patients with bipolar disorder or unipolar depression.
• CSF VASE concentration correlated with behavioral ratings in schizophrenia patients, but not in those with affective disorders.

Conclusions:

• VASE immunoreactivity is elevated in the CSF of individuals with schizophrenia, distinguishing it from affective disorders.
• These findings highlight a specific abnormality in N-CAM protein regulation in schizophrenia.
• The results suggest distinct molecular mechanisms underlying schizophrenia and affective disorders.