The precise assembly of a functional nervous system relies on axon guidance cues. Beyond engaging their cognate receptors and initiating signaling cascades that modulate cytoskeletal dynamics, guidance cues also bind components of the extracellular matrix, notably proteoglycans, yet the role and mechanisms of these interactions remain poorly understood. We found that Drosophila secreted semaphorins bind specifically to glycosaminoglycan (GAG) chains of proteoglycans, showing a preference based on the degree of sulfation. Structural analysis of Sema2b unveiled multiple GAG-binding sites positioned outside canonical plexin-binding site, with the highest affinity binding site located at the C-terminal tail, characterized by a lysine-rich helical arrangement that appears to be conserved across secreted semaphorins. In vivo studies revealed a crucial role of the Sema2b C-terminal tail in specifying the trajectory of olfactory receptor neurons. We propose that secreted semaphorins tether to the cell surface through interactions with GAG chains of proteoglycans, facilitating their presentation to cognate receptors on passing axons.
- Klíčová slova
- Sema2b, axon guidance, glycosaminoglycans, semaphorin, semaphorin bridge model,
- MeSH
- axony metabolismus MeSH
- čichové buňky metabolismus MeSH
- Drosophila melanogaster metabolismus MeSH
- glykosaminoglykany metabolismus MeSH
- navádění axonů * MeSH
- proteiny Drosophily * metabolismus genetika MeSH
- proteoglykany * metabolismus MeSH
- semaforiny * metabolismus genetika MeSH
- signální transdukce * MeSH
- vazba proteinů MeSH
- vazebná místa MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- Názvy látek
- glykosaminoglykany MeSH
- proteiny Drosophily * MeSH
- proteoglykany * MeSH
- semaforiny * MeSH
PURPOSE: To identify the molecular genetic cause in four families of various ethnic backgrounds with cornea plana. METHODS: Detailed ophthalmological examination and direct sequencing of the KERA coding region in five patients of Czech and Turkish origin and their available family members. RESULTS: Compound heterozygosity for a novel missense mutation c.209C>T; p.(Pro70Leu) and a novel splice site mutation c.887-1G>A in KERA were detected in two affected siblings of Czech origin. In silico analysis supported the pathogenicity of both variants. The second proband of Czech origin harboured c.835C>T; p.(Arg279*) in a homozygous state. Homozygous mutations c.740A>G; p.(Asn247Ser) and c.674C>T; p.(Ile225Thr) were identified in the Turkish probands, both born out of consanguineous marriages. Observed ocular phenotypes were typical of cornea plana with the exception of one Czech patient who also had marked thinning and protrusion in the superior part of the left cornea (mean keratometry 47.2 D). No corneal endothelial cell pathology was found by specular microscopy in seven eyes, in three eyes visualization of the posterior corneal surface was unsuccessful. CONCLUSION: KERA mutation c.740A>G has been identified to date in three different populations, which makes it the most frequently occurring mutation in patients with cornea plana. Marked corneal thinning and ectasia are a very rare finding in this disorder and longitudinal follow-up needs to be performed to determine its potential progressive nature.
- Klíčová slova
- KERA, cornea plana, novel mutation, phenotype,
- MeSH
- abnormality očí genetika metabolismus patologie MeSH
- DNA genetika MeSH
- lidé MeSH
- missense mutace * MeSH
- mladiství MeSH
- mladý dospělý MeSH
- mutační analýza DNA MeSH
- nemoci rohovky vrozené diagnóza MeSH
- optická koherentní tomografie MeSH
- předškolní dítě MeSH
- proteoglykany genetika metabolismus MeSH
- rodokmen MeSH
- rohovka abnormality metabolismus MeSH
- senioři MeSH
- sourozenci * MeSH
- Check Tag
- lidé MeSH
- mladiství MeSH
- mladý dospělý MeSH
- mužské pohlaví MeSH
- předškolní dítě MeSH
- senioři MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
- kazuistiky MeSH
- Geografické názvy
- Turecko MeSH
- Názvy látek
- DNA MeSH
- KERA protein, human MeSH Prohlížeč
- proteoglykany MeSH
Leishmania parasites are transmitted to vertebrate hosts by female phlebotomine sand flies as they bloodfeed by lacerating the upper capillaries of the dermis with their barbed mouthparts. In the sand fly midgut secreted proteophosphoglycans from Leishmania form a biological plug known as the promastigote secretory gel (PSG), which blocks the gut and facilitates the regurgitation of infective parasites. The interaction between the wound created by the sand fly bite and PSG is not known. Here we nanoinjected a sand fly egested dose of PSG into BALB/c mouse skin that lead to the differential expression of 7,907 transcripts. These transcripts were transiently up-regulated during the first 6 hours post-wound and enriched for pathways involved in inflammation, cell proliferation, fibrosis, epithelial cell differentiation and wound remodelling. We found that PSG significantly accelerated wound healing in vitro and in mice; which was associated with an early up-regulation of transcripts involved in inflammation (IL-1β, IL-6, IL-10, TNFα) and inflammatory cell recruitment (CCL2, CCL3, CCL4, CXCL2), followed 6 days later by enhanced expression of transcripts associated with epithelial cell proliferation, fibroplasia and fibrosis (FGFR2, EGF, EGFR, IGF1). Dermal expression of IGF1 was enhanced following an infected sand fly bite and was acutely responsive to the deposition of PSG but not the inoculation of parasites or sand fly saliva. Antibody blockade of IGF1 ablated the gel's ability to promote wound closure in mouse ears and significantly reduced the virulence of Leishmania mexicana infection delivered by an individual sand fly bite. Dermal macrophages recruited to air-pouches on the backs of mice revealed that IGF1 was pivotal to the PSG's ability to promote macrophage alternative activation and Leishmania infection. Our data demonstrate that through the regurgitation of PSG Leishmania exploit the wound healing response of the host to the vector bite by promoting the action of IGF1 to drive the alternative activation of macrophages.
- MeSH
- hojení ran účinky léků MeSH
- insulinu podobný růstový faktor I fyziologie MeSH
- interakce hostitele a parazita fyziologie MeSH
- kultivované buňky MeSH
- kůže účinky léků parazitologie patologie MeSH
- Leishmania mexicana metabolismus MeSH
- leishmanióza kožní parazitologie patologie MeSH
- makrofágy účinky léků metabolismus parazitologie patologie MeSH
- membránové proteiny metabolismus farmakologie MeSH
- myši inbrední BALB C MeSH
- myši MeSH
- progrese nemoci MeSH
- proteoglykany metabolismus farmakologie MeSH
- protozoální proteiny metabolismus farmakologie MeSH
- Psychodidae metabolismus MeSH
- signální transdukce účinky léků MeSH
- zvířata MeSH
- Check Tag
- myši MeSH
- ženské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- insulinu podobný růstový faktor I MeSH
- membránové proteiny MeSH
- Ppg1 protein, Leishmania MeSH Prohlížeč
- proteoglykany MeSH
- protozoální proteiny MeSH
Chondroitin sulfate proteoglycans (CSPGs) are the main active component of perineuronal nets (PNNs). Digestion of the glycosaminoglycan chains of CSPGs with chondroitinase ABC or transgenic attenuation of PNNs leads to prolongation of object recognition memory and activation of various forms of plasticity in the adult central nervous system. The inhibitory properties of the CSPGs depend on the pattern of sulfation of their glycosaminoglycans, with chondroitin 4-sulfate (C4S) being the most inhibitory form. In this study, we tested a number of candidates for functional blocking of C4S, leading to selection of an antibody, Cat316, which specifically recognizes C4S and blocks its inhibitory effects on axon growth. It also partly blocks binding of semaphorin 3A to PNNs and attenuates PNN formation. We asked whether injection of Cat316 into the perirhinal cortex would have the same effects on memory as chondroitinase ABC treatment. We found that masking C4S with the Cat316 antibody extended long-term object recognition memory in normal wild-type mice to 24 hours, similarly to chondroitinase or transgenic PNN attenuation. We then tested Cat316 for restoration of memory in a neurodegeneration model. Mice expressing tau with the P301S mutation showed profound loss of object recognition memory at 4 months of age. Injection of Cat316 into the perirhinal cortex normalized object recognition at 3 hours in P301S mice. These data indicate that Cat316 binding to C4S in the extracellular matrix can restore plasticity and memory in the same way as chondroitinase ABC digestion. Our results suggest that antibodies to C4S could be a useful therapeutic to restore memory function in neurodegenerative disorders.
- Klíčová slova
- Alzheimer's disease, CSPGs, Object recognition memory, Perineuronal nets, Plasticity,
- MeSH
- Alzheimerova nemoc farmakoterapie etiologie patofyziologie psychologie MeSH
- antigeny imunologie metabolismus fyziologie MeSH
- cílená molekulární terapie MeSH
- extracelulární matrix metabolismus MeSH
- kultivované buňky MeSH
- lidé MeSH
- modely nemocí na zvířatech MeSH
- myši inbrední C57BL MeSH
- myši transgenní MeSH
- neurodegenerativní nemoci farmakoterapie etiologie patofyziologie psychologie MeSH
- neuroplasticita MeSH
- neutralizující protilátky terapeutické užití MeSH
- paměť fyziologie MeSH
- potkani Sprague-Dawley MeSH
- proteoglykany imunologie metabolismus fyziologie MeSH
- protilátky aplikace a dávkování MeSH
- reakční čas MeSH
- tauopatie komplikace MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- mužské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- antigeny MeSH
- Cat316 antibody MeSH Prohlížeč
- chondroitin sulfate proteoglycan 4 MeSH Prohlížeč
- neutralizující protilátky MeSH
- proteoglykany MeSH
- protilátky MeSH
NG2 cells represent one of the most proliferative glial cell populations in the intact mammalian central nervous system (CNS). They are well-known for their ability to renew themselves or to generate new oligodendrocytes during development as well as in adulthood, therefore also being termed oligodendrocyte progenitor cells. Following CNS injuries, such as demyelination, trauma or ischemia, the proliferative capacity of NG2 cells rapidly increases and moreover, their differentiation potential broadens, as documented by numerous reports also describing their differentiation into astrocytes or even neurons. Here, we summarize the current knowledge about NG2 cells proliferation, their fate plasticity during embryogenesis as well as in postnatal CNS under physiological and pathological conditions, with the main emphasis on the role of various signaling molecules, growth factors, hormones or even neurotransmitters on the fate potential of NG2 cells.
- Klíčová slova
- Astrocytes, Glioma, Myelin plasticity, NG2 cells, Oligodendrocyte precursor cells (OPC),
- MeSH
- antigeny metabolismus MeSH
- kmenové buňky účinky léků fyziologie MeSH
- látky ovlivňující centrální nervový systém farmakologie terapeutické užití MeSH
- lidé MeSH
- mezibuněčné signální peptidy a proteiny metabolismus MeSH
- multipotentní kmenové buňky účinky léků fyziologie transplantace MeSH
- neurogeneze účinky léků fyziologie MeSH
- neuroglie účinky léků fyziologie MeSH
- neuroplasticita účinky léků fyziologie MeSH
- oligodendroglie účinky léků fyziologie MeSH
- proliferace buněk účinky léků fyziologie MeSH
- proteoglykany metabolismus MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- přehledy MeSH
- Názvy látek
- antigeny MeSH
- látky ovlivňující centrální nervový systém MeSH
- mezibuněčné signální peptidy a proteiny MeSH
- proteoglykany MeSH
Oligodendrocyte progenitor cells (OPCs) play a pivotal role in both health and disease within the central nervous system, with oligodendrocytes, arising from resident OPCs, being the main myelinating cell type. Disruption in OPC numbers can lead to various deleterious health defects. Numerous studies have described techniques for isolating OPCs to obtain a better understanding of this cell type and to open doors for potential treatments of injury and disease. However, the techniques used in the majority of these studies involve several steps and are time consuming, with current culture protocols using serum and embryonic or postnatal cortical tissue as a source of isolation. We present a primary culture method for the direct isolation of functional adult rat OPCs, identified by neuron-glial antigen 2 (NG2) and platelet derived growth factor receptor alpha (PDGFrα) expression, which can be obtained from the adult spinal cord. Our method uses a simple serum-free cocktail of 3 growth factors - FGF2, PDGFAA, and IGF-I, to expand adult rat OPCs in vitro to 96% purity. Cultured cells can be expanded for at least 10 passages with very little manipulation and without losing their phenotypic progenitor cell properties, as shown by immunocytochemistry and RT-PCR. Cultured adult rat OPCs also maintain their ability to differentiate into GalC positive cells when incubated with factors known to stimulate their differentiation. This new isolation method provides a new source of easily accessible adult stem cells and a powerful tool for their expansion in vitro for studies aimed at central nervous system repair.
- Klíčová slova
- Adult spinal cord, CNS, Differentiation, Progenitor cells, Spinal cord injury,
- MeSH
- antigeny metabolismus MeSH
- destičkový růstový faktor metabolismus MeSH
- dospělé kmenové buňky cytologie metabolismus MeSH
- fibroblastový růstový faktor 2 metabolismus MeSH
- insulinu podobný růstový faktor I metabolismus MeSH
- krysa rodu Rattus MeSH
- mícha cytologie metabolismus MeSH
- oligodendroglie cytologie metabolismus MeSH
- potkani Sprague-Dawley MeSH
- proteoglykany metabolismus MeSH
- separace buněk * MeSH
- zvířata MeSH
- Check Tag
- krysa rodu Rattus MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- antigeny MeSH
- chondroitin sulfate proteoglycan 4 MeSH Prohlížeč
- destičkový růstový faktor MeSH
- fibroblastový růstový faktor 2 MeSH
- insulin-like growth factor-1, rat MeSH Prohlížeč
- insulinu podobný růstový faktor I MeSH
- platelet-derived growth factor A MeSH Prohlížeč
- proteoglykany MeSH
Endocan is a soluble molecule secreted from vascular endothelial cells of various organs. Its exact function in humans remains to be elucidated, though it has been postulated that increased tissue expression or serum levels of this molecule may be an indicator of endothelial activation and neovascularization. In the realm of forensic pathology, studies pertaining to endothelial activation following exposure to cold exclusively focused on thrombomodulin, a transmembrane protein specific to endothelial cells. In the study herein described, endocan concentrations were determined in postmortem serum, urine and vitreous humor samples collected during autopsy in a series of cases that underwent medicolegal investigations. A total of 76 autopsy cases were selected and three study groups (hypothermia group, sepsis group and non-hypothermia/non-sepsis group) prospectively formed during the study period. The obtained results seem to indicate that exposure to cold and subsequent death is not distinguished by significant endothelial dysfunction causing enhanced endocan secretion.
- Klíčová slova
- Autopsy, Endocan, Endothelium, Hypothermia, Postmortem biochemistry, Postmortem serum, Urine, Vitreous humor,
- MeSH
- biologické markery metabolismus MeSH
- dospělí MeSH
- hypotermie diagnóza metabolismus MeSH
- lidé středního věku MeSH
- lidé MeSH
- mladý dospělý MeSH
- nádorové proteiny metabolismus MeSH
- posmrtné změny MeSH
- prospektivní studie MeSH
- proteoglykany metabolismus MeSH
- senioři MeSH
- sklivec metabolismus MeSH
- soudní patologie MeSH
- Check Tag
- dospělí MeSH
- lidé středního věku MeSH
- lidé MeSH
- mladý dospělý MeSH
- mužské pohlaví MeSH
- senioři MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
- Názvy látek
- biologické markery MeSH
- ESM1 protein, human MeSH Prohlížeč
- nádorové proteiny MeSH
- proteoglykany MeSH
Chondroitin sulfate (CS) proteoglycans in perineuronal nets (PNNs) from the central nervous system (CNS) are involved in the control of plasticity and memory. Removing PNNs reactivates plasticity and restores memory in models of Alzheimer's disease and ageing. Their actions depend on the glycosaminoglycan (GAG) chains of CS proteoglycans, which are mainly sulfated in the 4 (C4S) or 6 (C6S) positions. While C4S is inhibitory, C6S is more permissive to axon growth, regeneration and plasticity. C6S decreases during critical period closure. We asked whether there is a late change in CS-GAG sulfation associated with memory loss in aged rats. Immunohistochemistry revealed a progressive increase in C4S and decrease in C6S from 3 to 18 months. GAGs extracted from brain PNNs showed a large reduction in C6S at 12 and 18 months, increasing the C4S/C6S ratio. There was no significant change in mRNA levels of the chondroitin sulfotransferases. PNN GAGs were more inhibitory to axon growth than those from the diffuse extracellular matrix. The 18-month PNN GAGs were more inhibitory than 3-month PNN GAGs. We suggest that the change in PNN GAG sulfation in aged brains renders the PNNs more inhibitory, which lead to a decrease in plasticity and adversely affect memory.
- Klíčová slova
- aging, glycosaminoglycans, perineuronal net, plasticity, sulfation,
- MeSH
- buněčné extrakty MeSH
- krysa rodu Rattus MeSH
- messenger RNA MeSH
- mozek metabolismus MeSH
- nervová síť fyziologie MeSH
- neurity účinky léků MeSH
- poruchy paměti etiologie MeSH
- proteoglykany metabolismus MeSH
- regulace genové exprese fyziologie MeSH
- stárnutí fyziologie MeSH
- sulfotransferasy genetika metabolismus MeSH
- zvířata MeSH
- Check Tag
- krysa rodu Rattus MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- buněčné extrakty MeSH
- messenger RNA MeSH
- proteoglykany MeSH
- sulfotransferasy MeSH
Cationic colloidal gold nanorods (GNRs) have a great potential as a theranostic tool for diverse medical applications. GNRs' properties such as cellular internalization and stability are determined by physicochemical characteristics of their surface coating. GNRs modified by (16-mercaptohexadecyl)trimethylammonium bromide (MTAB), MTABGNRs, show excellent cellular uptake. Despite their promise for biomedicine, however, relatively little is known about the cellular pathways that facilitate the uptake of GNRs, their subcellular fate and intracellular persistence. Here we studied the mechanism of cellular internalization and long-term fate of GNRs coated with MTAB, for which the synthesis was optimized to give higher yield, in various human cell types including normal diploid versus cancerous, and dividing versus nondividing (senescent) cells. The process of MTABGNRs internalization into their final destination in lysosomes proceeds in two steps: (1) fast passive adhesion to cell membrane mediated by sulfated proteoglycans occurring within minutes and (2) slower active transmembrane and intracellular transport of individual nanorods via clathrin-mediated endocytosis and of aggregated nanorods via macropinocytosis. The expression of sulfated proteoglycans was the major factor determining the extent of uptake by the respective cell types. Upon uptake into proliferating cells, MTABGNRs were diluted equally and relatively rapidly into daughter cells; however, in nondividing/senescent cells the loss of MTABGNRs was gradual and very modest, attributable mainly to exocytosis. Exocytosed MTABGNRs can again be internalized. These findings broaden our knowledge about cellular uptake of gold nanorods, a crucial prerequisite for future successful engineering of nanoparticles for biomedical applications such as photothermal cancer therapy or elimination of senescent cells as part of the emerging rejuvenation approach.
- MeSH
- buněčná membrána účinky léků metabolismus MeSH
- endocytóza účinky léků fyziologie MeSH
- exocytóza * účinky léků fyziologie MeSH
- konfokální mikroskopie MeSH
- kultivační média MeSH
- kvartérní amoniové sloučeniny chemická syntéza chemie MeSH
- lidé MeSH
- lyzozomy účinky léků MeSH
- mikroskopie elektronová rastrovací MeSH
- nádorové buněčné linie MeSH
- nanotrubičky analýza chemie MeSH
- polylysin chemie farmakokinetika MeSH
- proliferace buněk účinky léků MeSH
- proteoglykany chemie metabolismus MeSH
- průtoková cytometrie MeSH
- stabilita léku MeSH
- sulfhydrylové sloučeniny chemie MeSH
- techniky syntetické chemie MeSH
- zlato chemie farmakokinetika MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- Názvy látek
- (16-mercaptohexadecyl)trimethylammonium bromide MeSH Prohlížeč
- cationic colloidal gold MeSH Prohlížeč
- kultivační média MeSH
- kvartérní amoniové sloučeniny MeSH
- polylysin MeSH
- proteoglykany MeSH
- sulfhydrylové sloučeniny MeSH
- zlato MeSH
The aim of the study is co-localization of N-glycans with fucose attached to N-acetylglucosamine in α1,3 linkage, that belong to immunogenic carbohydrate epitopes in humans, and N-glycans with α1,6-core fucose typical for mammalian type of N-linked glycosylation. Both glycan epitopes were labelled in cryosections of salivary glands isolated from the tick Ixodes ricinus. Salivary glands secrete during feeding many bioactive molecules and influence both successful feeding and transmission of tick-borne pathogens. For accurate and reliable localization of labelled glycans in both fluorescence and scanning electron microscopes, we used carbon imprints of finder or indexed EM grids on glass slides. We discuss if the topographical images can provide information about labelled structures, the working setting of the field-emission scanning electron microscope and the influence of the detector selection (a below-the-lens Autrata improved YAG detector of back-scattered electrons; in-lens and conventional Everhart-Thornley detectors of secondary electrons) on the imaging of gold nanoparticles, quantum dots and osmium-stained membranes.
- MeSH
- barvení a značení metody MeSH
- elektronová kryomikroskopie přístrojové vybavení metody MeSH
- fluorescenční mikroskopie přístrojové vybavení metody MeSH
- klíště * metabolismus ultrastruktura MeSH
- mikroskopie elektronová rastrovací přístrojové vybavení metody MeSH
- proteiny členovců metabolismus MeSH
- proteoglykany metabolismus MeSH
- sklo MeSH
- slinné proteiny a peptidy metabolismus MeSH
- slinné žlázy * metabolismus ultrastruktura MeSH
- uhlík MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- proteiny členovců MeSH
- proteoglykany MeSH
- slinné proteiny a peptidy MeSH
- uhlík MeSH