CSF levels of diazepam-binding inhibitor correlate with REM latency in schizophrenia, a pilot study

Lumbar cerebrospinal fluid proteome in multiple sclerosis: characterization by ultrafiltration, liquid chromatography, and mass spectrometry

Neurological diseases, including multiple sclerosis (M.S.), often provoke changes in the functioning of the endothelial and epithelial brain barriers and give rise to disease-associated alterations of the cerebrospinal fluid (CSF) proteome. In the present study, pooled and ultrafiltered CSF of M.S. and non-M.S. patients was digested with trypsin and analyzed by off-line strong cation-exchange chromatography (SCX) coupled to on-line reversed-phase LC-ESI-MS/MS. In an alternative approach, the trypsin-treated subproteomes were analyzed directly by LC-ESI-MS/MS and gas-phase fractionation in the mass spectrometer. Taken together, both proteomic approaches in combination with a three-step evaluation process including the search engines Sequest and Mascot, and the validation software Scaffold, resulted in the identification of 148 proteins. Sixty proteins were identified in CSF for the first time by mass spectrometry. For validation purposes, the concentration of cystatin A was determined in individual CSF and serum samples of M.S. and non-M.S. patients using ELISA.

Benzodiazepines in perspective (II): The GABAA-Benzodiazepine Receptor Ligands

A huge number of natural and synthetic compounds modulate the function of the γ-aminobutyric acid type A receptor (GABAA-R) by interacting with several allosteric binding sites which may differ in the various GABAA-R subtypes. The benzodiazepine receptor (BDZ-R) is the most intensively studied allosteric site. It is the first allosteric modulatory site on a neurotransmitter receptor that has been found to mediate two opposite functions: facilitation and depression of GABAA-R function. The effects of BDZ-R ligands on behavior range from agonistic (anxiolytic, anticonvulsant, myore-laxant/ataxic and hypno-sedative effects) to inverse-agonistic (anxiety and panic, hypervigilance and convulsions). Of particular interest for the future are BDZ-R partial agonists, as they lack several of the undesired properties of classic full agonists. Furthermore the GABAA-R system shows a high plasticity. This polymorphism raises the possibility that ligands selective for distinct subtypes of BDZ-R may emerge as useful drugs. In both cases the possibility exists of achieving very subtle manipulations of GABAA-R function by using allosteric modulators.

Comparative proteome analysis of the hippocampus implicates chromosome 6q in schizophrenia

Comparative brain proteome analysis is a new strategy to discover proteins and therefore genes whose altered expression may underlie schizophrenia. This strategy does not require an a priori theory of the pathogenesis or the mode of inheritance of schizophrenia. Using proteome analysis we previously compared the hippocampal proteome, that is, those proteins expressed by the hippocampal genome, of seven schizophrenic individuals with the hippocampal proteome of seven control individuals, matched for age and post mortem delay.1 We found 18 proteins that were significantly altered in concentration in the schizophrenic hippocampus (P < 0.05), when compared to control tissue. One of these proteins was characterised, by N-terminal sequencing, as diazepam binding inhibitor whose gene maps to 6q12-q21. Here we characterise a further three of the 18 proteins as: manganese superoxide dismutase, 6q25.3, T-complex protein 1, 6q25.3-q26 and collapsin response mediator protein 2, 8p21. That three of these four characterised proteins should map to the long arm of the same chromosome is significant (P < 0.002) and suggests the importance of chromosome 6q in schizophrenia. These results indicate that antioxidant defence is altered in the schizophrenic hippocampus and suggest that segregation distortion, of schizophrenia susceptibility genes, may be a possible causative factor in the high incidence of schizophrenia. Molecular Psychiatry (2000) 5, 85-90.