Non-motor Behavioral Alterations of PGC-1 alpha-Deficient Mice - A Peculiar Phenotype With Slight Male Preponderance and No Apparent Progression

Dysfunction of peroxisome proliferator-activated receptor gamma coactivator-1alpha (PGC-1 alpha) has been linked to various neurodegenerative and neuropsychiatric disorders; however, reports on psychic behavioral alterations on PGC-1 alpha-deficient animals are sparse. The present study revisited prior observations of anxiety-related, depression-related, and hippocampal memory-related observations having been made on different PGC-1 alpha-deficient murine strains, in a large-scale analysis on whole-body full-length (FL-)PGC-1 alpha-deficient mice. The examinations were performed on animals covering a wide age range enrolled from both sexes, and included paradigms such as the open-field, elevated plus maze, light-dark box, tail suspension test, and spatial recognition two-trial V-maze. The findings revealed no signs of previously reported anxiety-like behavior, but revealed an unexpected phenotype with decreased anxiety behavior consistent throughout different paradigms, with slight male preponderance. This was associated with despair-like anhedonic behavior, consistent with that reported previously, but did not associate with either peripheral or brain alterations in kynurenic acid synthesis, which was previously proposed. Though male FL-PGC-1 alpha-deficient mice tended to perform poorer in the hippocampus-based spatial learning paradigm, the genotype overall was not associated with impairment in spatial memory, contradicting with prior observations. None of the observed alterations deteriorated with age, similarly to motor alterations as reported previously. The most likely contributors of this peculiar phenotype are discussed, with clinicopathological correlations drawn. Being the first to address these behavioral domains within the same PGC-1 alpha-deficient strain, our findings extend the knowledge about the complex in vivo effect of PGC-1 alpha dysfunction and add important notes to research in the field of PGC-1 alpha in connection with neuropsychiatric disorders

The Tryptophan-Kynurenine Metabolic System Is Suppressed in Cuprizone-Induced Model of Demyelination Simulating Progressive Multiple Sclerosis

Progressive multiple sclerosis (MS) is a chronic disease with a unique pattern, which is histologically classified into the subpial type 3 lesions in the autopsy. The lesion is also homologous to that of cuprizone (CPZ) toxin-induced animal models of demyelination. Aberration of the tryptophan (TRP)-kynurenine (KYN) metabolic system has been observed in patients with MS; nevertheless, the KYN metabolite profile of progressive MS remains inconclusive. In this study, C57Bl/6J male mice were treated with 0.2% CPZ toxin for 5 weeks and then underwent 4 weeks of recovery. We measured the levels of serotonin, TRP, and KYN metabolites in the plasma and the brain samples of mice at weeks 1, 3, and 5 of demyelination, and at weeks 7 and 9 of remyelination periods by ultra-high-performance liquid chromatography with tandem mass spectrometry (UHPLC-MS/MS) after body weight measurement and immunohistochemical analysis to confirm the development of demyelination. The UHPLC-MS/MS measurements demonstrated a significant reduction of kynurenic acid, 3-hydoxykynurenine (3-HK), and xanthurenic acid in the plasma and a significant reduction of 3-HK, and anthranilic acid in the brain samples at week 5. Here, we show the profile of KYN metabolites in the CPZ-induced mouse model of demyelination. Thus, the KYN metabolite profile potentially serves as a biomarker of progressive MS and thus opens a new path toward planning personalized treatment, which is frequently obscured with immunologic components in MS deterioration

Investigating KYNA production and kynurenergic manipulation on acute mouse brain slice preparations

Manipulation of kynurenic acid (KYNA) level through kynurenine aminotransferase-2 (KAT-2) inhibition with the aim of therapy in neuro-psychiatric diseses has been the subject of extensive recent research. Although mouse models are of particular importance, neither the basic mechanism of KYNA production and release nor the relevance of KAT-2 in the mouse brain has yet been clarified. Using acute mouse brain slice preparations, we investigated the basal and L-kynurenine (L-KYN) induced KYNA production and distribution between the extracellular and intracellular compartments. Furthermore, we evaluated the effect of specific KAT-2 inhibition with the irreversible inhibitor PF-04859989. To ascertain that the observed KYNA release is not a simple consequence of general cell degradation, we examined the structural and functional integrity of the brain tissue with biochemical, histological and electrophysiological tools. We did not find relevant change in the viability of the brain tissue after several hours incubation time. HPLC measurements proved that mouse brain slices intensively produce and liberate KYNA to the extracellular compartment, while only a small proportion retained in the tissue both in the basal and L-KYN supplemented state. Finally, specific KAT-2 inhibition significantly reduced the extracellular KYNA content. Taken together, these results provide important data about KYNA production and release, and in vitro evidence for the first time of the function of KAT-2 in the adult mouse brain. Our study extends investigations of KAT-2 manipulation to mice in a bid to fully understand the function; the final, future aim is to assign therapeutical kynurenergic manipulation strategies to humans

Enzimreakciók vizsgálata a moduláris szerveződés, az atomi kölcsönhatás és a kvantummechanika szintjein. A fehérje biofizika tudományos iskolája = Insight into the Enzyme Action at Levels of modular Organization, Atomic Interactions and Quantum-Mechanics. School of Protein Biophysics

Az elmúlt 3 év koherens kutató munkája során születtek speciális tudományos eredmények és levontunk ezekből általános következtetéseket is. Munkánk mérlege a nemzetközi folyóiratokban megjelent 30 közlemény összesen 130 IF-al. Molekuláris immunológiai kutatásaink keretében meghatároztuk 4 komplement proteáz és a C1-inhibitor szerkezetét, különösen az utóbbi hozott számunkra nagy nemzetközi elismerést. A szerkezetek és funkcionális eredményeink alapján általánosan elfogadott aktiválási modellt dolgoztunk ki a komplement rendszer lektin útjának szabályozási mechanizmusára. Jelentősnek tartjuk a C1-inhibitor heparin által történő potencirozásának mechanizmusára javasolt, szerkezeti alapú modell kidolgozását, a flagellin fehérje egyik rendezetlen szakaszának export szignálként történő azonosítását (szabadalom is született belőle), a foszfoglicerátkináz enzim domén záródásban résztvevő allosztérikus jeltovábbító hálózat azonosítását, az enzimaktivitás rendhagyó hőmérsékletfüggésének a konformációs flexibilitás alapján történő értelmezését a izopropilmalát dehidrogenáz esetében, átmeneti zóna felfedezését a rendezett és rendezetlen szerkezetet kódoló aminósav szekvencák között. A komplement fehérjék és funkcionális komplexeik, a flagelláris rendszerek, multidomén enzimek együttes vizsgálata lehetővé tette a fehérjék önszerveződésével, a molekuláris szintű felismeréssel és az allosztérikus jeltovábbítás mechanizmusával kapcsolatos általános következtetések levonását. | We have determined the structure of C1-Inhibitor and four complement proteinases: C1r, MASP1, MASP2 in zymogen form and MASP2 in activated form. Based on our structural and functional studies we concluded a mechanistic model for the activation of the lectin pathway of the complement system. We also devised a structure based model for the heparin potentiation of C1-Inhibitor. An intrinsically disordered sequence of the bacterial flagellin protein was identified as an export signal (patented). Other significant achievements: the mapping of an allosteric network involved in the ligand induced hinge closure of phosphoglycerate kinase, the interpretation of the odd temperature dependence in the catalytic activity of isopropylmalate dehydrogenase in terms of concerted conformational fluctuations, discovery of the twilight zone between amino acid sequences encoding ordered and disordered conformations. Our coherent studies on the functional protein complexes of the complement system, on flagellar systems, multidomain enzymes enabled us to make some general conclusions regarding the self assembly, recognition and allosteric behaviour of proteins and protein complexes

Development and Identification of a 4HL.5DL Wheat/Barley Centric Fusion Using GISH, FISH and SSR Markers

The 4H(4D) wheat/barley substitution line was crossed with the 'Chinese Spring' ph1b mutant genotype in order to induce wheat-barley homoeologous recombinations. F-3 and F-4 seeds of the 4H(4D) x 'Chinese Spring' ph1b mutant cross were analysed using genomic in situ hybridization, and a Robertsonian translocation was detected in monosomic form. Disomic centric fusions were selected among the self-fertilized progenies. The presence of the long arm of 4H was confirmed with SSR markers. The long arm of the 5D wheat chromosome in the Robertsonian translocation was identified using fluorescent in situ hybridization with the help of three DNA probes: pSc119.2, Afa family and pTa71. The wheat/barley centric fusion was identified as a 4HL.5DL translocation. This line exhibited supernumerary spikelet character, but the number of seeds/plant did not increase. The 4HL.5DL centric fusion line is suitable genetic material to study the expression of genes located on 4HL in a wheat genetic background