Research Article Open Access Short Communication Open Access Semančíková et al., J Proteomics Bioinform 2018, 11:5 DOI: 10.4172/jpb.1000476 Journal of Proteomics & Bioinformatics J o u r n a l o f P r o t e o m i c s & B i o i n f o r m a t i c s ISSN: 0974-276X Volume 11(5) 117-119 (2018) - 117 J Proteomics Bioinform, an open access journal ISSN: 0974-276X *Corresponding authors: Semančíková Erika, 2nd Department of Psychiatry, University Hospital of Louis Pasteur, Rastislavova 43, 04001, Košice, Slovakia, Tel: +421-55-234-3401; Fax: +421-55-234-3401; E-mail: tasiiik@gmail.com Received May 18, 2018; Accepted June 11, 2018; Published June 18, 2018 Citation: Semančíková E, Tkáčiková S, Talian I, Bober P, Tomečková V, et al. (2018) Proteomic Analysis of Cerebrospinal Fluid in Suicidal Patients - A Pilot Study. J Proteomics Bioinform 11: 117-119. doi: 10.4172/jpb.1000476 Copyright: © 2018 Semančíková E, et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Short Communication Despite the fact that “omic” technologies (including genomic, epigenomic, transcriptomic, proteomic and metabolomic technologies) are becoming widely used in various medical felds, their use in psychiatry is still very limited. Assessing suicidal behavior in psychiatric practice consists mostly of semi-structured questionnaires or various self-assessing scales. Information obtained this way is rather subjective. Terefore, our proteomic approach may provide more valid and objective way how to assess suicidality in daily clinical practice by fnding possible candidates for biomarkers of suicidal behavior. In the present short communication, we present and discuss the results of our pilot proteomic study of cerebrospinal fuid (CSF) in two adult suicidal patients post-mortem (males, average age: 55, cause of death: hanging, no concomitant medication, no medical history), two adult controls post-mortem (males, average age: 55, cause of death: heart attack, no concomitant medication, no medical history) and two adult controls in-vivo (females, average age: 55, diagnosis: hydrocephalus, no concomitant medication – samples were drawn before the medication was taken). Samples of CSF in-vivo were included in this study to confrm the presence of identifed proteins in living subjects and also to defne their levels in CSF. Per subject, 5 ml of CSF was collected and post-mortem interval (PMI) did not exceed 32 hours. Te protocol and informed consents for this study were approved by local ethical committee. Proteomic analysis using trypsin digestion was performed on Bruker AmaZon speed ETD Ion Trap mass spectrometer (Bruker Daltonics, Germany) connected with UltiMate 3000 UHPLC Termo Scientifc system. HPLC analysis was performed on trap column Acclaim PepMap 100 (Termo Scientifc, 100 µm x 2 cm, 5 µm) with loading solvent water-acetonitrile containing 0.1% formic acid in isocratic mode. Peptides were separated on Acclaim PepMap RLSC analytical column (Termo Scientifc 75 µm x 15 cm, 3 µm) with mobile phase composition of acetonitrile - water with 0.1 % formic acid in gradient elution. For protein identifcation the Mascot 2.4 search engine was used (taxonomy: homo sapiens, variable modifcation: oxidation of methionine, fxed modifcation: carbamidomethylation of cysteine, MS tolerance: 0.6 Da, MS/MS tolerance: 0.9 Da, FDR ≤ 1 %). For protein identifcation and label-free quantifcation the Scafold 4.8.6 (Proteome Sofware Inc., Portland, OR, USA) sofware was used to validate MS/MS based peptide and protein identifcations. Peptide identifcations were accepted if they could be established at greater than 95.0% probability by the Peptide Prophet algorithm with Scafold delta-mass correction. Protein identifcations were accepted if they could be established at greater than 99.0% probability and contained at least 2 identifed peptides. Protein probabilities were assigned by the Protein Prophet algorithm. Te label-free quantitative proteomic analysis utilizing the Total Spectral Count quantifcation method (data were normalized) showed statistically signifcant changes in 69 proteins, i.e., those passing ANOVA test (p<0.05) (Supplementary Proteomic Analysis of Cerebrospinal Fluid in Suicidal Patients - A Pilot Study Semančíková Erika 1,2* , Tkáčiková Soňa 3 , Talian Ivan 3 , Bober Peter 3 , Tomečková Vladimíra 2 and Hertelyová Zdenka 4 1 2nd Department of Psychiatry, University Hospital of Louis Pasteur, Rastislavova 43, 04001, Košice, Slovakia 2 Institute of Medical and Clinical Biochemistry, Faculty of Medicine, University of Pavel Jozef Šafárik, Trieda SNP 1, 04001, Košice, Slovakia 3 Institute of Medical and Clinical Biophysics, Faculty of Medicine, University of Pavel Jozef Šafárik, Trieda SNP 1, 04001, Košice, Slovakia 4 Department of Experimental Medicine, Faculty of Medicine, University of Pavel Jozef Šafárik, Trieda SNP 1, 04001, Košice, Slovakia Table S1). Analysis of protein-protein interactions using STRING database in 69 signifcantly changed proteins was performed (Figure 1). From these 69 signifcantly changed proteins, Enolase 1 (ENO1), Enolase 2 (ENO2), Glyceraldehyde-3-phosphate (G3P) and Triose-phosphate isomerase (TPI) were signifcantly downregulated (p<0.05) and Aldolase C (ALDOC) signifcantly upregulated (p<0.05) in glycolysis/gluconeogenesis pathway, while protein 14-3-3 eta (YWHAH) and 14-3-3 theta (YWHAQ) had signifcantly higher levels in 14-3-3 mediated signaling pathway in CSF of suicidal patients versus control subjects. Glycolytic proteins had signifcantly lower concentrations in suicidal patients compared to controls, what might indicate decreased utilisation of glucose in central nervous system (CNS), while the signifcantly higher concentration (p<0.05) of ALDOC in suicidal patients versus controls might be interpreted as an example of compensation mechanisms of the already decreased utilisation of glucose in CNS. We therefore suggest, that dysregulation in glucose utilisation may play a role in patients with suicidal behavior as well as in other psychiatric diseases e.g. schizophrenia. Some proteomic evidence using post-mortem brain tissue of schizophrenic patients also found dysregulations in glycolysis/gluconeogenesis metabolism. Tis fnding was interpreted as possible increase in glucose demand and/or cellular hypoxia. For example, enzyme ALDOC was both found upregulated [1- 3] and downregulated [4,5] in several studies. Prabakaran et al. [6] also identifed dysregulations in several glycolytic enzymes (ENO1, ENO2, ALDOC and GP3) in prefrontal cortex of schizophrenic patients post- mortem. Peroxiredoxine 2 (PRDX2) and ENO2 play a role in oxidative stress response, while ENO2 is also considered as a marker of nervous tissue damage. In our pilot study, signifcantly lower concentrations of both enzymes were observed in suicidal patients versus controls, what might be considered as possibly decreased oxidative stress response. PRDX2 was also found downregulated in schizophrenic patients [7]. Furthermore, statistically signifcant upregulation (p<0.05) of protein 14-3-3 eta (YWHAH) and 14-3-3 theta (YWHAQ) in 14-3-3 mediated signaling pathway was found in suicidal patients compared to control subjects in our pilot study. Kékesi et al. [8] also identifed elevated levels of YWHAH, but not of YWHAQ in prefrontal cortex and amygdala in suicidal attempters compared with control group