The difference in serum proteomes in schizophrenia and bipolar disorder

Liudmila Smirnova,German Simutkin,Victor Zgoda,Irina Boksha,Olga Savushkina,Svetlana Ivanova,Alexander Seregin,Elena Dmitrieva,Anastasia Letova,Elena Kornetova,Nikolay Bokhan

doi:10.1186/s12864-019-5848-1

Abstract

BackgroundPurpose of study is revealing significant differences in serum proteomes in schizophrenia and bipolar disorder (BD).ResultsQuantitative mass-spectrometry based proteomic analysis was used to quantify proteins in the blood serum samples after the depletion of six major blood proteins. Comparison of proteome profiles of different groups revealed 27 proteins being specific for schizophrenia, and 18 – for BD. Protein set in schizophrenia was mostly associated with immune response, cell communication, cell growth and maintenance, protein metabolism and regulation of nucleic acid metabolism. Protein set in BD was mostly associated with immune response, regulating transport processes across cell membrane and cell communication, development of neurons and oligodendrocytes and cell growth. Concentrations of ankyrin repeat domain-containing protein 12 (ANKRD12) and cadherin 5 in serum samples were determined by ELISA. Significant difference between three groups was revealed in ANKRD12 concentration (p = 0.02), with maximum elevation of ANKRD12 concentration (median level) in schizophrenia followed by BD. Cadherin 5 concentration differed significantly (p = 0.035) between schizophrenic patients with prevailing positive symptoms (4.78 [2.71, 7.12] ng/ml) and those with prevailing negative symptoms (1.86 [0.001, 4.11] ng/ml).ConclusionsOur results are presumably useful for discovering the new pathways involved in endogenous psychotic disorders.

Highlights

Purpose of study is revealing significant differences in serum proteomes in schizophrenia and bipolar disorder (BD)
Bioinformatics approach using MaxQuant version 1.6.3.4. applied to the group of patients with schizophrenia and to the group of patients with BD has resulted in identification of unique proteins that have not been met in other groups
Comparison of proteome profiles of different groups revealed 27 proteins being specific for schizophrenia, and 18 – for BD

Summary

Introduction

Purpose of study is revealing significant differences in serum proteomes in schizophrenia and bipolar disorder (BD). Schizophrenia and BD are the most important mental disorders for social life. They represent a heterogeneous group of endogenous mental disorders with unclarified etiology and pathophysiological mechanisms at present, and these are the causes of difficulties in prediction of responses to treatment and outcomes for the patients with these disorders. When compared proteome profiles between schizophrenia, BD, and MDD, only 30 proteins were changed in all three disorders. Small overlapping between changes in protein levels typical for major mental disorders can be a feature maintaining specificity of every disease at proteome level [7]. Most often, when studying the proteomic profile of patients with mental disorders, non-specific proteins are detected. Some studies of sera from patients with BD have revealed proteins associated with mitochondrial dysfunction and energy metabolism impairment [16,17,18,19]

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Results

Conclusion