Immunfehérjék akcióban

2012-t az UNESCO Szentágothai emlékévvé nyilvánította. A legendás neuroanatómus és egyetemi tanár emléke előtt tisztelegve egy olyan vizsgálati technikát mutatunk be, amelynek segítségével láthatóvá és megérthetővé válhatnak a Szentágothai János kutatásának is középpontjában álló neuronális hálózatok, azok funkcionális anatómiája

Anatomical Distribution of Nucleoside System in the Human Brain and Implications for Therapy

Nucleosides have a wide range of physiological and pathophysiological roles in the human brain as modulators of a variety of neural functions. For example, adenosine, inosine, guanosine, and uridine participate in the mechanisms underlying memory, cognition, sleep, pain, depression, schizophrenia, epilepsy, Alzheimer’s disease, Huntington’s disease, and Parkinson’s disease. Consequently, increasing attention is now being given to the speci fi c role of nucleosides in physiological and pathological processes in the human brain. Different elements of nucleoside system, including nucleoside concentrations, metabolic enzyme activity, and expression of nucleoside transporters and receptors, may be changed under normal and pathological conditions. The alterations suggest that interlinked elements of the nucleoside system are functioning in a tightly concerted manner. Nucleoside levels, activity of nucleoside metabolic enzymes, and expression of nucleoside transporters and receptors are unevenly distributed in the brain, suggesting that nucleosides have different roles in functionally distinct human brain areas. The aim of this chapter is to summarize our present knowledge of the anatomical distribution of nucleoside system in the human brain, placing emphasis on potential therapeutic pharmacological strategies

Preoptic Inputs and Mechanisms that Regulate Maternal Responsiveness

The preoptic area is a well-established centre for the control of maternal behaviour. An intact medial preoptic area (mPOA) is required for maternal responsiveness because lesion of the area abolishes maternal behaviours. Although hormonal changes in the peripartum period contribute to the initiation of maternal responsiveness, inputs from pups are required for its maintenance. Neurones are activated in different parts of the mPOA in response to pup exposure. In the present review, we summarise the potential inputs to the mPOA of rodent dams from the litter that can activate mPOA neurones. The roles of potential indirect effects through increased prolactin levels, as well as neuronal inputs to the preoptic area, are described. Recent results on the pathway mediating the effects of suckling to the mPOA suggest that neurones containing the neuropeptide tuberoinfundibular peptide of 39 residues in the posterior thalamus are candidates for conveying the suckling information to the mPOA. Although the molecular mechanism through which these inputs alter mPOA neurones to support the maintenance of maternal responding is not yet known, altered gene expression is a likely candidate. Here, we summarise gene expression changes in the mPOA that have been linked to maternal behaviour and explore the idea that chromatin remodelling during mother-infant interactions mediates the long-term alterations in gene expression that sustain maternal responding

Appearance of fast astrocytic component in voltage-sensitive dye imaging of neural activity.

BACKGROUND: Voltage-sensitive dye (VSD) imaging and intrinsic optical signals (IOS) are widely used methods for monitoring spatiotemporal neural activity in extensive networks. In spite of that, identification of their major cellular and molecular components has not been concluded so far. RESULTS: We addressed these issues by imaging spatiotemporal spreading of IOS and VSD transients initiated by Schaffer collateral stimulation in rat hippocampal slices with temporal resolution comparable to standard field potential recordings using a 464-element photodiode array. By exploring the potential neuronal and astroglial molecular players in VSD and IOS generation, we identified multiple astrocytic mechanisms that significantly contribute to the VSD signal, in addition to the expected neuronal targets. Glutamate clearance through the astroglial glutamate transporter EAAT2 has been shown to be a significant player in VSD generation within a very short (<5 ms) time-scale, indicating that astrocytes do contribute to the development of spatiotemporal VSD transients previously thought to be essentially neuronal. In addition, non-specific anion channels, astroglial K(+) clearance through Kir4.1 channel and astroglial Na(+)/K(+) ATPase also contribute to IOS and VSD transients. CONCLUSION: VSD imaging cannot be considered as a spatially extended field potential measurement with predominantly neuronal origin, instead it also reflects a fast communication between neurons and astrocytes

Transzformáló növekedési faktor béta fehérjék a központi idegrendszerben = Transforming growth factor beta proteins in the central nervous system

A három TGF-béta altípus agyban való eloszlása specifikus, vagyis elkülönült idegrendszeri funkcióik lehetnek. A TGF-béta1 magas expressziót mutatott a hypothalamusz preoptikus területén, ahol eloszlása hasonló volt azonosított anyai neuropeptidekéhez. Ez arra utal, hogy a TGF-béta1 szerepet játszhat az idegrendszer anyai adaptációiban. Emellett a TGF-béta rendszer elemeit azonosítottuk a laterális hypothalamus orexin sejtjeiben is. A TGF-béta fehérjék neuroprotektív folyamatokban való részvételét is vizsgáltuk. Fokális agyi ischaemiát idéztünk elő az egyik középső agyi artéria okklúziójával. Ennek hatására TGF-béta1 indukálódott a lézió körüli penumbrában. A TGF-béta2 és 3 expressziója viszont máshol, az azonos oldali agykéreg II, III, és V. rétegének teljes hosszában növekedett meg. A TGF-béta1 együttes expressziót mutatott az ATF-3-al, míg a TGF-béta2 és 3 Fos fehérjét kifejező sejtekben indukálódott. Egyik neurontípus sem festődött Fluoro Jade C-vel, egy neurodegenerációt jelző markerrel. Eredményeink arra utalnak, hogy az endogen TGF-béta fehérjék részt vehetnek neuroprotektív funkciókban, de ischaemiás eseményt követően eltérő mechanizmussal indukálódnak. Szintén megvizsgáltuk a TGF-béta rendszert a TGF-béta kötőfehérje 1 hiányában knock-out egérben, és jelentős változást nem tapasztaltunk. Összességében elmondhatjuk, hogy a pályázat keretében szerzett új ismereteknek jelentős szerepe van az agy TGF-béta rendszerének megértésében, és a rendszer jövőbeli kihasználásában ischaemiás stroke-ot követően. | The topographical distribution of mRNAs of the 3 TGF-betas in the brain were characteristic of the particular type of TGF-beta suggesting that they play a role in separate brain functions. TGF-beta1 was abundantly expressed in the preoptic area of the hypothalamus with a distribution similar to identified maternal neuropeptides in the region suggesting that TGF-beta1 may play a role in maternal adaptations. We also identified elements of the TGF-beta system in orexin neurons of the lateral hypothalamus. The involvement of TGF-betas in neuroprotection has also been established. Focal brain ischemia was induced with unilateral occlusion of the middle cerebral artery. TGF-beta1 was induced in the penumbra around the lesion. The expression of TGF-beta2 and 3 was increased in layers II, III, and V of the ipsilateral cerebral cortex. TGF-beta1 was co-localized with ATF-3 while TGF-beta2 appeared in Fos-expressing cells. In turn, these neurons did not contain Fluoro Jade C, a marker of neurodegeneration. Thus, endogenous TGF-betas may participate in neuroprotection, although they are induced by different mechanisms following an ischemic attack. We also examined the TGF-beta system in the absence of TGF-beta binding protein 1 in knock-out mice and found no major effects. Collectively, the new knowledge gained in the framework of the proposal is expected to have a major positive impact on understanding the TGF-beta system in the central nervous system and its utilization to alleviate the consequences of ischemic stroke

Lipopolysaccharide induced increase in seizure activity in two animal models of absence epilepsy WAG/Rij and GAERS rats and Long Evans rats

We showed previously that the number and time of spike-wave discharges (SWDs) were increased after intraperitoneal (i.p.) injection of lipopolysaccharide (LPS), an effect, which was completely abolished by cyclooxygenase-2 (COX-2) inhibitor indomethacin (IND) pretreatment in Wistar Albino Glaxo/Rijswijk (WAG/Rij) rats. These and other results suggest that injection of LPS to genetically absence epileptic animals, such as WAG/Rij rats, may allow us to investigate relationships between absence epilepsy and LPS evoked neuroinflammation processes. However, LPS may evoke different effects on absence epileptic activity in various animal strains. Thus, to extend our previous results, we injected two doses of LPS (50 μg/kg and 350 μg/kg i.p.) alone and in combination with IND (10mg/kg IND i.p. +50 μg/kg LPS) into rats of two model animal strains (WAG/Rij rats; GAERS rats: Genetic Absence Epileptic Rats from Strasbourg) and into Long Evans rats. The effects of treatments on SWD number and SWD duration were examined. Both doses of LPS increased the SWD number and the total time of SWDs dose-dependently during the whole 4-h recording period, which was abolished by IND pretreatment in all three investigated strains. These results extend our previous results suggesting that our methods using LPS injection into freely moving absence epileptic rats is applicable not only in well-established animal models of absence epilepsy such as WAG/Rij rats and GAERS rats but also in Long Evans rats to investigate links between inflammation and absence epilepsy

Szignálátvitelhez kapcsolódó gének izolálása Gibberella fujikuroiból = Cloning of genes connected to signal transduction of Gibberella fujikuroi

Összefoglalás A gomba MAP (mitogén aktivált protein) kináz gének szekvenciaelemzésével a szerzők új alcsoport-specifikus YSAPK és YERK MAP kináz motívumokat azonosítottak és PCR-alapú klónozási rendszert dolgoztak ki a fonalas gombák körében. Meghatározták a Fusarium proliferatum két MAP kináz génje (Fphog1 és Fpmk2) genomi szekvenciáját. Az YSAPK alcsoportba tartozó DeltaFphog1 mutáns funkcionális vizsgálata és komplementálása igazolta a gén abiotikus stressztoleranciában (hő-, só-, ozmotikus, UV-C és hidrogén-peroxid stressz) betöltött fontos szerepét. A só- és ozmotikus stressz esetében a szerzők igazolták, hogy az Fphog1 gén a programozott sejthalál (PCD) negatív regulátora. A rendelkezésre álló adatok szerint ez az első közlemény a HOG-típusú MAP kinázok apoptózisban játszott szerepéről. A só- ill. ozmotikus stressznek kitett DeltaFphog1 mutáns micéliumsejtekben négy ismert apoptózis marker fokozott jelenlétét azonosították: aktív oxigénformák képződése, mitokondriális membránpotenciál változása, sejtmagok dezintegrációja és a DNS fragmentációja. A Fusarium verticillioides YERK2 alcsoportba tartozó DeltaFvmk2 MAPK mutánsa fokozott szenzitivitást mutatott a sejtfal dezintegrációját kiváltó anyagokkal (kongó vörös, SDS) szemben. A mutáns szenzitívebb volt az alkohol- és formamid-kezeléssel szemben is. A gomba apoptózis modell illetve az Fvmk2 MAPK gén alkohol- és formamid-toleranciában játszott szerepe gyakorlati felhasználási lehetőségeket kínál a jövőben. | Based on multiple sequence alignment of fungal mitogen activated protein kinase (MAPK) genes, new YSAPK and YERK MAPK subgroup specific motifs were identified within filamentous species. Using this approach, a nested PCR-based cloning strategy was developed to clone genomic sequences of two MAP kinase genes (Fphog1 and Fpmk2) from Fusarium proliferatum. Functional analysis and complementation of three independent DeltaFphog1 mutants verified the fundamental role of this MAPK gene in multiple abiotic stress tolerance (heat, salt, osmotic, UV-C and hydrogen peroxide stresses). Detailed analysis of the effect of salt (NaCl) and osmotic (sorbitol) stressors identified Fphog1 gene as a negative regulator of programmed cell death (PCD). According to our knowledge this is the first report on the role of a HOG-type MAPK gene in the regulation of apoptosis. Four apoptosis markers were detected in mycelial cells of DeltaFphog1 mutant strain: increased level of active oxygen species (AOS), changes in mitochondrial membrane potential, nuclear disintegration and DNA fragmentation. The DeltaFvmk2 mutant of F. verticillioides showed increased sensitivity to treatments with cell wall disintegrating compounds such as SDS and congo red. This mutant was also sensitive to ethanol and formamide treatments. The fungal apoptosis model and the role of Fvmk2 MAPK in alcohol and formamide tolerance offer practical possibilities in the future