Ovarian hyperstimulation syndrome (OHSS) is an iatrogenic complication and potentially life-threatening condition resulting from excessive ovarian stimulation during assisted reproductive technologies. Our aim was to identify candidate proteins in follicular fluid (FF) using various proteomic approaches which may help to identify patients at risk of OHSS. We analysed the proteome alterations in FF from patients suffering from severe forms of OHSS (OHSS+) compared with a control group of women without or with only mild signs of OHSS (OHSS−). The 12 abundant proteins of FF were removed using an immunoaffinity system. Pools of remaining depleted proteins were applied to the two-dimensional (2D) electrophoresis and 2D liquid chromatography and proteins in differentially expressed protein spots/fractions were identified by mass spectrometry. Among a total of 19 candidate proteins differentially expressed (P< 0.05) between OHSS+ and OHSS− FF samples, three proteins, namely ceruloplasmin, complement C3 and kininogen-1, were found using both 2D techniques. Computer modelling highlighted the important role of kininogen-1 as an anchor for mediated interactions with other identified proteins including ferritin light chain and ceruloplasmin, hepatocyte growth factor-like protein, as well as complement C3 and gelsolin, thus linking various biological processes including inflammation and angiogenesis, iron transport and storage, blood coagulation, innate immunity, cell adhesion and actin filament polymerization. The delineation of such processes may allow the development of informed corrective therapeutic intervention in patients at risk of OHSS and a set of key proteins of the FF may be helpful as potential biomarkers for monitoring IVF therapy.

Neural stem cells (NSC) capable of differentiating into neurons, astrocytes and oligodendrocytes are a promising source of cells for the treatment of central nervous system diseases. Access to signaling proteins present in such cells in low copies and with specific regulatory functions has been very restrictive until now as judged by classical proteomic approaches and limitations due to scarcity of stem cell populations. Hence, we utilized the Kinex™ Antibody Microarray analysis where profiles of the proliferating porcine NSC and differentiated counterparts were compared and selected changes were verified by immunoblotting. Differentiated neural cells exhibited an increased level of RafB proto‐oncogene‐encoded protein‐serine kinase, MAP kinase protein‐serine kinase 3, heme oxygenase 2 (HO2) and protein phosphatase 4 catalytical subunit. On the other hand, relatively high level of G protein‐coupled receptor‐serine kinase 2 and enhanced phosphorylations of αB‐crystallin (S45), protein‐serine kinase C gamma (T655), protein‐serine kinase D (PKCμ; S738+S742) together with eukaryotic translation initiation factor 2 alpha (eIF2α) (S51) raised intriguing questions as regards their potential functionality within stem cells. In‐depth study of HO2 and phospho‐S45 αB‐crystallin confirmed expression profiles and intense cytoplasmic localization of HO2 in neurons but a weaker signal in glial cells. Phospho‐S45 αB‐crystallin was localized in nuclei of differentiated neural cells. Computer simulation of possible interaction network connecting regulated proteins, exposed additional relationships including direct interactions of HO2 with amyloid precursor protein or huntingtin‐associated protein 1.