Axonal swellings (AS) are one of the neuropathological hallmark of axonal injury in several disorders from trauma to neurodegeneration. Current evidence proposes a role of perturbed Ca2+ homeostasis in AS formation, involving impaired axonal transport and focal distension of the axons. Mechanisms of AS formation, in particular moments following injury, however, remain unknown. Here we show that AS form independently from intra-axonal Ca2+ changes, which are required primarily for the persistence of AS in time. We further show that the majority of axonal proteins undergoing de/phosphorylation immediately following injury belong to the cytoskeleton. This correlates with an increase in the distance of the actin/spectrin periodic rings and with microtubule tracks remodeling within AS. Observed cytoskeletal rearrangements support axonal transport without major interruptions. Our results demonstrate that the earliest axonal response to injury consists in physiological adaptations of axonal structure to preserve function rather than in immediate pathological events signaling axonal destruction.

• MeSH
• aktiny metabolismus   MeSH
• axonální transport fyziologie   MeSH
• axony patologie   MeSH
• lidé MeSH
• spektrin * metabolismus   MeSH
• traumatické poranění mozku * patologie   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH

Proton detection in solid state NMR is continuously developing and allows one to gain new insights in structural biology. Overall, this progress is a result of the synergy between hardware development, new NMR methodology and new isotope labeling strategies, to name a few factors. Even though current developments are rapid, it is worthwhile to summarize what can currently be achieved employing proton detection in biological solids. We illustrate this by analysing the signal-to-noise ratio (SNR) for spectra obtained for a microcrystalline α-spectrin SH3 domain protein sample by (i) employing different degrees of chemical dilution to replace protons by incorporating deuterons in different sites, by (ii) variation of the magic angle spinning (MAS) frequencies between 20 and 110 kHz, and by (iii) variation of the static magnetic field B0. The experimental SNR values are validated with numerical simulations employing up to 9 proton spins. Although in reality a protein would contain far more than 9 protons, in a deuterated environment this is a sufficient number to achieve satisfactory simulations consistent with the experimental data. The key results of this analysis are (i) with current hardware, deuteration is still necessary to record spectra of optimum quality; (ii) 13CH3 isotopomers for methyl groups yield the best SNR when MAS frequencies above 100 kHz are available; and (iii) sensitivity increases with a factor beyond B0 3/2 with the static magnetic field due to a transition of proton-proton dipolar interactions from a strong to a weak coupling limit.

• MeSH
• deuterium chemie   MeSH
• protonová terapie * MeSH
• protony * MeSH
• spektrin chemie   MeSH
• src homologní domény MeSH
• Publikační typ
• časopisecké články MeSH
• přehledy MeSH

SPTBN1 encodes βII-spectrin, the ubiquitously expressed β-spectrin that forms micrometer-scale networks associated with plasma membranes. Mice deficient in neuronal βII-spectrin have defects in cortical organization, developmental delay and behavioral deficiencies. These phenotypes, while less severe, are observed in haploinsufficient animals, suggesting that individuals carrying heterozygous SPTBN1 variants may also show measurable compromise of neural development and function. Here we identify heterozygous SPTBN1 variants in 29 individuals with developmental, language and motor delays; mild to severe intellectual disability; autistic features; seizures; behavioral and movement abnormalities; hypotonia; and variable dysmorphic facial features. We show that these SPTBN1 variants lead to effects that affect βII-spectrin stability, disrupt binding to key molecular partners, and disturb cytoskeleton organization and dynamics. Our studies define SPTBN1 variants as the genetic basis of a neurodevelopmental syndrome, expand the set of spectrinopathies affecting the brain and underscore the critical role of βII-spectrin in the central nervous system.

• MeSH
• dominantní geny * MeSH
• fenotyp MeSH
• genetická predispozice k nemoci * MeSH
• genetická variace * MeSH
• genetické asociační studie metody   MeSH
• heterozygot MeSH
• lidé MeSH
• myši MeSH
• neurovývojové poruchy diagnóza   genetika   MeSH
• spektrin genetika   metabolismus   MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Research Support, N.I.H., Extramural MeSH

Sensitivity and resolution together determine the quality of NMR spectra in biological solids. For high-resolution structure determination with solid-state NMR, proton-detection emerged as an attractive strategy in the last few years. Recent progress in probe technology has extended the range of available MAS frequencies up to above 100 kHz, enabling the detection of resolved resonances from sidechain protons, which are important reporters of structure. Here we characterise the interplay between MAS frequency in the newly available range of 70-110 kHz and proton content on the spectral quality obtainable on a 1 GHz spectrometer for methyl resonances. Variable degrees of proton densities are tested on microcrystalline samples of the α-spectrin SH3 domain with selectively protonated methyl isotopomers (CH3, CH2D, CHD2) in a perdeuterated matrix. The experimental results are supported by simulations that allow the prediction of the sensitivity outside this experimental frequency window. Our results facilitate the selection of the appropriate labelling scheme at a given MAS rotation frequency.

• MeSH
• deuterium chemie   MeSH
• metylace * MeSH
• nukleární magnetická rezonance biomolekulární metody   MeSH
• protony * MeSH
• senzitivita a specificita MeSH
• spektrin chemie   MeSH
• src homologní domény MeSH
• Publikační typ
• časopisecké články MeSH

Nuclear actin plays an important role in such processes as chromatin remodeling, transcriptional regulation, RNA processing, and nuclear export. Recent research has demonstrated that actin in the nucleus probably exists in dynamic equilibrium between monomeric and polymeric forms, and some of the actin-binding proteins, known to regulate actin dynamics in cytoplasm, have been also shown to be present in the nucleus. In this paper, we present ultrastructural data on distribution of actin and various actin-binding proteins (alpha-actinin, filamin, p190RhoGAP, paxillin, spectrin, and tropomyosin) in nuclei of HeLa cells and resting human lymphocytes. Probing extracts of HeLa cells for the presence of actin-binding proteins also confirmed their presence in nuclei. We report for the first time the presence of tropomyosin and p190RhoGAP in the cell nucleus, and the spatial colocalization of actin with spectrin, paxillin, and alpha-actinin in the nucleolus.

• MeSH
• aktinin MeSH
• aktiny analýza   MeSH
• buněčné jádro chemie   ultrastruktura   MeSH
• financování organizované MeSH
• HeLa buňky MeSH
• jaderné proteiny analýza   MeSH
• lidé MeSH
• lymfocyty chemie   ultrastruktura   MeSH
• mikrofilamentové proteiny analýza   MeSH
• paxilin MeSH
• proteiny aktivující GTPasu MeSH
• spektrin MeSH
• tropomyosin MeSH
• Check Tag
• lidé MeSH

Phenylhydrazine and its derivatives were first given a medical application at the end of the 19th century but with with very little benefit. However, this compound seems to be very useful in models studying mechanisms of haemolytic anaemia. Phenylhydrazine induces a reactive oxygen species formation peroxidation of lipids and oxidative degradation of spectrin in the membrane skeleton. PHZ-induced haemolytic injury seems to be derived from oxidative alternations to red blood cell proteins. This compound can modulate immune reactions.

• MeSH
• exprese genu imunologie   účinky záření   MeSH
• fenylhydraziny farmakokinetika   škodlivé účinky   terapeutické užití   MeSH
• hemolytické anemie etiologie   krev   MeSH
• membránové proteiny fyziologie   MeSH
• peroxidace lipidů účinky léků   účinky záření   MeSH
• reaktivní formy kyslíku škodlivé účinky   MeSH
• spektrin chemie   MeSH
• testy genotoxicity využití   MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH

Three major cytoskeletal proteins, actin, tubulin and spectrin, are present in the head of mammalian spermatozoa. Although cytoskeletal proteins are implicated in the regulation of capacitation and the acrosome reaction (AR), their exact role remains poorly understood. The aim of this study was to compare the distribution of the sperm head cytoskeleton before and after the AR in spermatozoa representing a range of acrosome size and shape. Spermatozoa from the human and three rodents (rat, hamster and grey squirrel) were fixed before and after the AR in appropriate medium in vitro. Indirect immunofluorescent localization of cytoskeletal proteins was undertaken with antibodies recognizing actin, spectrin and alpha-tubulin. Preparations were counterstained with propidium iodide and examined by epifluorescent and confocal microscopy. Our results clearly demonstrated changes in localization of cytoskeleton during the AR, mainly in the apical acrosome with further changes to the equatorial segment and post-acrosomal regions. The pattern of cytoskeletal proteins in the sperm head of all the species was similar in respect to various sub-compartments. These observations indicated that the sperm head cortical cytoskeleton exhibits significant changes during the AR and, therefore, support the image of cytoskeletal proteins as highly dynamic structures participating actively in processes prior to fertilization.

• MeSH
• akrozomální reakce fyziologie   MeSH
• aktiny analýza   MeSH
• biologické markery analýza   MeSH
• cytoskeletální proteiny analýza   ultrastruktura   MeSH
• financování organizované MeSH
• fluorescenční mikroskopie MeSH
• fluorescenční protilátková technika nepřímá MeSH
• hlavička spermie ultrastruktura   MeSH
• konfokální mikroskopie MeSH
• křečci praví MeSH
• krysa rodu rattus MeSH
• Sciuridae MeSH
• spektrin analýza   MeSH
• tubulin analýza   MeSH
• zvířata MeSH
• Check Tag
• křečci praví MeSH
• krysa rodu rattus MeSH
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• zvířata MeSH

Charakterizace mutací vedoucích k hereditární sferocytose za účelem pochopení patogenese hereditární sferocytosy a úlohy jednotlivých proteinů v erytrocytami menbráně.Korelace mezi typem a polohou mutaci a klinickým průběhem hereditarní sferocytosy.; Charcterization of mutation underlying hereditary spherocytosis in order to elucidate its pathogenesis and the role of the mutant proteins in red cell membrane.Correlation between the type of the mutations and the clinical course of spherocytosis.

• MeSH
• ankyriny genetika   MeSH
• dědičná sférocytóza patofyziologie   MeSH
• elektroforéza využití   metody   MeSH
• fluorescenční protilátková technika využití   MeSH
• membránové proteiny MeSH
• průtoková cytometrie využití   metody   MeSH
• spektrin genetika   MeSH

• Konspekt
• Patologie. Klinická medicína
• NLK Obory
• hematologie a transfuzní lékařství
• chemie, klinická chemie
• NLK Publikační typ
• závěrečné zprávy o řešení grantu IGA MZ ČR

• MeSH
• buněčná membrána fyziologie   MeSH
• elektrická vodivost MeSH
• erytrocyty MeSH
• fosforylace MeSH
• lidé MeSH
• spektrin metabolismus   MeSH
• techniky in vitro MeSH
• teplota MeSH
• Check Tag
• lidé MeSH

• MeSH
• aktiny MeSH
• dítě MeSH
• erytrocyty patologie   MeSH
• hyperbilirubinemie MeSH
• lidé MeSH
• lipidové dvojvrstvy MeSH
• novorozenec s nízkou porodní hmotností MeSH
• novorozenec MeSH
• novorozenecká žloutenka MeSH
• spektrin MeSH
• Check Tag
• dítě MeSH
• lidé MeSH
• novorozenec MeSH
• Publikační typ
• srovnávací studie MeSH