The Plasma Proteomic Study In Depressed Patients With Suicide Attempts

Background Depression is a kind of affective disorder characterizedby persistent depressed mood，high prevalence，high recurrence rate, andhigh rates of suicide. It causes a heavy burden to the patient’s family andsocial. The prevalence rate of major depression is l0%in America,3%inchina. There are about10million people have suicidal ideation each year inthe world,50%-70％of them are depressed patients. To prevent suicide inpatients with depression is the primary concern, factors related to suicide inpatients with depression are multiple and complex, looking for theLaboratory parameter related to suicide become a research hotspot.Objective Differences of plasma proteome in depressed patients withsuicide attempts and healthy volunteers were analyzed base ontwo-dimensional gel electrophoresis （2-DE） and mass spectrometrytechnology, in order to find plasma biomarkers in depressed patients withSuicide attempts，then this biomarkers will provide the basis for earlyclinical prediction, prevention of suicidal behavior in depressed patients.Methods Plasma samples from6depressed patients with suicideattempts，6healthy volunteers. The most abundant protein in plasma wasdepleted in order to enrich low-abundance proteins and proteins with low molecular weight. The samples were separated by two-dimensionalelectrophoresis (2-DE) and analyzed with ImageMaster2D Platinumsoftware. The differentially expressed protein spots in plasma fromdepressed patients with suicide attempts were analyzed bypeptide-fingerprinting with matrix-assisted laser desorption/ionization timeof flight mass spectrometry (MALDI-TOF-MS). Then the Meaningfulproteins were validated by western blot.Results A total of11protein spot-features were found to besignificantly different between depressed patients with suicide attempts andhealthy volunteers. The identified proteins included clusterin, ApoA-I,ApoA-IV, ApoC-Ⅲ, Vitamin D-binding protein (VDB). Compared withthe control group，clusterin, ApoA-I, ApoA-IV and ApoC-Ⅲ increase indepressed patients with suicide attempts, but VDB decreased. Western blotshow that ApoA-I and VDB have significant difference, but not ApoA-IVand ApoC-Ⅲ, Western blot result of VDB is inconsistent with itstwo-dimensional electrophoresis.Conclusions The proteins Identified by two-dimensional gelelectrophoresis combined with mass spectrometry Associated with suicidalbehavior in patients with depression, the protein ApoA-I might be appliedas biomarker for depressed patients with suicide attempts.