Proteomic analysis of the postsynaptic density implicates synaptic function and energy pathways in bipolar disorder.

Area of Science:

• Neuroscience
• Molecular Biology
• Psychiatry

Background:

• The postsynaptic density (PSD) is crucial for synaptic function and implicated in neuropsychiatric disorders.
• Alterations in PSD protein composition are linked to conditions like schizophrenia and bipolar disorder.

Purpose of the Study:

• To investigate differentially expressed proteins within the PSD in bipolar disorder.
• To identify the specific biological pathways affected in the anterior cingulate cortex of individuals with bipolar disorder.

Main Methods:

• Utilized unbiased shotgun proteomics with label-free quantitation on PSD-enriched samples from bipolar disorder patients and controls.
• Performed quantitative analysis to identify differentially expressed proteins.
• Validated key protein expression changes using western blotting.

Main Results:

• Identified 2033 proteins in the PSD, with 288 found to be differentially expressed in bipolar disorder.
• Bioinformatics analysis implicated metabolic pathways, including mitochondrial function, the tricarboxylic acid cycle, and oxidative phosphorylation.
• Confirmed expression changes for specific proteins: DNM1, DTNA, NDUFV2, SEPT11, and SSBP.

Conclusions:

• PSD-associated proteins, particularly those involved in mitochondrial function, are implicated in bipolar disorder.
• Synaptic function and its underlying energy pathways are significantly related to bipolar disorder.
• Findings support a broader link between PSD and mitochondrial dysfunction in psychiatric disorders, emphasizing its importance in bipolar disorder.