Myelin is a multilayered membrane that tightly wraps neuronal axons, enabling efficient, high-speed signal propagation. The axon and myelin sheath form tight contacts, mediated by specific plasma membrane proteins and lipids, and disruption of these contacts causes devastating demyelinating diseases. Using two cell-based models of demyelinating sphingolipidoses, we demonstrate that altered lipid metabolism changes the abundance of specific plasma membrane proteins. These altered membrane proteins have known roles in cell adhesion and signaling, with several implicated in neurological diseases. The cell surface abundance of the adhesion molecule neurofascin (NFASC), a protein critical for the maintenance of myelin-axon contacts, changes following disruption to sphingolipid metabolism. This provides a direct molecular link between altered lipid abundance and myelin stability. We show that the NFASC isoform NF155, but not NF186, interacts directly and specifically with the sphingolipid sulfatide via multiple binding sites and that this interaction requires the full-length extracellular domain of NF155. We demonstrate that NF155 adopts an S-shaped conformation and preferentially binds sulfatide-containing membranes in cis, with important implications for protein arrangement in the tight axon-myelin space. Our work links glycosphingolipid imbalances to disturbance of membrane protein abundance and demonstrates how this may be driven by direct protein-lipid interactions, providing a mechanistic framework to understand the pathogenesis of galactosphingolipidoses.

• MeSH
• demyelinizační nemoci * patologie   MeSH
• glykosfingolipidy metabolismus   MeSH
• lidé MeSH
• molekuly buněčné adheze metabolismus   MeSH
• myelinová pochva metabolismus   MeSH
• neurotrofní faktory metabolismus   MeSH
• sulfoglykosfingolipidy * MeSH
• transportní proteiny metabolismus   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

The ability to adhere via colonization factors to specific receptors located on the intestinal mucosa is a key virulence factor in enterotoxigenic Escherichia coli (ETEC) pathogenesis. Here, the potential glycosphingolipid receptors of the novel human ETEC colonization factor CS30 were examined by binding of CS30-expressing bacteria to glycosphingolipids on thin-layer chromatograms. We thereby found a highly specific binding of CS30-expressing bacteria to a fast-migrating acid glycosphingolipid of human and porcine small intestine, while no binding was obtained with a mutant ETEC strain unable to express CS30 fimbriae. The CS30 binding glycosphingolipid from human small intestine was isolated and characterized by mass spectrometry as sulfatide (SO3-3Galβ1Cer). Comparative binding studies using sulfatides with different ceramide compositions gave a preferential binding of CS30 to sulfatide with d18:1-h24:0 ceramide. This ceramide species of sulfatide was also isolated from human small intestine and characterized by mass spectrometry and antibody binding. These studies implicate sulfatide as candidate receptor for mediating attachment of CS30-fimbriated ETEC to human and porcine small intestinal cells. Our findings may be a basis for designing receptor saccharide analogues for inhibition of the intestinal adhesion of CS30-expressing E. coli.

• MeSH
• bakteriální adheze * MeSH
• ceramidy analýza   MeSH
• enterotoxigenní Escherichia coli metabolismus   MeSH
• faktory virulence metabolismus   MeSH
• glykosfingolipidy metabolismus   MeSH
• lidé MeSH
• prasata MeSH
• proteiny fimbrií genetika   metabolismus   MeSH
• proteiny z Escherichia coli metabolismus   MeSH
• střevní sliznice cytologie   mikrobiologie   MeSH
• sulfoglykosfingolipidy metabolismus   MeSH
• tenké střevo cytologie   mikrobiologie   MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

BACKGROUND Leishmania major is an Old World species causing cutaneous leishmaniasis and is transmitted by Phlebotomus papatasi and Phlebotomus duboscqi. In Brazil, two isolates from patients who never left the country were characterised as L. major-like (BH49 and BH121). Using molecular techniques, these isolates were indistinguishable from the L. major reference strain (FV1). OBJECTIVES We evaluated the lipophosphoglycans (LPGs) of the strains and their behaviour in Old and New World sand fly vectors. METHODS LPGs were purified, and repeat units were qualitatively evaluated by immunoblotting. Experimental in vivo infection with L. major-like strains was performed in Lutzomyia longipalpis (New World, permissive vector) and Ph. papatasi (Old World, restrictive or specific vector). FINDINGS The LPGs of both strains were devoid of arabinosylated side chains, whereas the LPG of strain BH49 was more galactosylated than that of strain BH121. All strains with different levels of galactosylation in their LPGs were able to infect both vectors, exhibiting colonisation of the stomodeal valve and metacyclogenesis. The BH121 strain (less galactosylated) exhibited lower infection intensity compared to BH49 and FV1 in both vectors. MAIN CONCLUSIONS Intraspecific variation in the LPG of L. major-like strains occur, and the different galactosylation levels affected interactions with the invertebrate host.

• MeSH
• druhová specificita MeSH
• galaktosa metabolismus   MeSH
• glykosfingolipidy chemie   metabolismus   MeSH
• hmyz - vektory chemie   fyziologie   MeSH
• interakce hostitele a patogenu MeSH
• Leishmania major chemie   fyziologie   MeSH
• Phlebotomus parazitologie   MeSH
• Psychodidae parazitologie   MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH

Blood group B glycosphingolipids (B-GSLs) are substrates of the lysosomal alpha-galactosidase A (AGAL). Similar to its major substrate-globotriaosylceramide (Gb3Cer)-B-GSLs are not degraded and accumulate in the cells of patients affected by an inherited defect of AGAL activity (Fabry disease-FD).The pancreas is a secretory organ known to have high biosynthesis of blood group GSLs. Herein, we provide a comprehensive overview of the biochemical and structural abnormalities in pancreatic tissue from two male FD patients with blood group B. In both patients, we found major accumulation of a variety of complex B-GSLs carrying predominantly hexa- and hepta-saccharide structures. The subcellular pathology was dominated by deposits containing B-glycoconjugates and autofluorescent ceroid. The contribution of Gb3Cer to the storage was minor. This abnormal storage pattern was specific for the pancreatic acinar epithelial cells. Other pancreatic cell types including those of islets of Langerhans were affected much less or not at all.Altogether, we provide evidence for a key role of B-antigens in the biochemical and morphological pathology of the exocrine pancreas in FD patients with blood group B. We believe that our findings will trigger further studies aimed at assessing the potential pancreatic dysfunction in this disease.

• MeSH
• ABO systém krevních skupin metabolismus   MeSH
• acinární buňky metabolismus   ultrastruktura   MeSH
• beta-buňky metabolismus   ultrastruktura   MeSH
• Fabryho nemoc krev   metabolismus   patologie   MeSH
• galaktosa analýza   metabolismus   MeSH
• glykosfingolipidy chemie   metabolismus   MeSH
• lidé středního věku MeSH
• lidé MeSH
• pankreas metabolismus   ultrastruktura   MeSH
• studie případů a kontrol MeSH
• Check Tag
• lidé středního věku MeSH
• lidé MeSH
• mužské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

The lipophosphoglycan (LPG) of Leishmania major has a major role in the attachment to Phlebotomus papatasi midgut. Here, we investigated the comparative structural features of LPG of L. turanica, another species transmitted by P. papatasi. The mAb WIC 79.3, specific for terminal Gal(β1,3) side-chains, strongly reacted with L. turanica LPG. In contrast, L. turanica LPG was not recognized by arabinose-specific mAb 3F12. In conclusion, LPGs from L. major and L. turanica are similar, with the latter being less arabinosylated than L. major's. The high galactose content in L. turanica LPG is consistent with its predicted recognition by P. papatasi lectin PpGalec.

• MeSH
• druhová specificita MeSH
• glykosfingolipidy chemie   genetika   metabolismus   MeSH
• hmyz - vektory parazitologie   MeSH
• Leishmania genetika   metabolismus   MeSH
• Phlebotomus parazitologie   MeSH
• regulace genové exprese MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Binding of promastigotes to the sand fly midgut epithelium is regarded as an essential part of the Leishmania life cycle in the vector. Among Leishmania surface molecules putatively involved in attachment to the sand fly midgut, two GPI-anchored molecules are the most prominent: lipophosphoglycan (LPG) and promastigote surface protease gp63. In this work, we examined midgut attachment of Leishmania lines mutated in GPI-anchored molecules and compared results from 2 different techniques: in vivo development in sand flies and in vitro competitive binding assays using fluorescently labelled parasites. In combination with previous studies, our data provide additional support for (1) an LPG-independent parasite-binding mechanism of Leishmania major within the midgut of the permissive vector Phlebotomus perniciosus, and provide strong support for (2) the crucial role of L. major LPG in specific vector Phlebotomus papatasi, and (3) a role for Leishmania amazonensis gp63 in Lutzomyia longipalpis midgut binding. Moreover, our results suggest a critical role for GPI-anchored proteins and gp63 in Leishmania mexicana attachment to L. longipalpis midguts, as the wild type (WT) line accounted for over 99% of bound parasites.

• MeSH
• galaktosyltransferasy genetika   metabolismus   MeSH
• glykokonjugáty genetika   metabolismus   MeSH
• glykosfingolipidy genetika   metabolismus   MeSH
• hmyz - vektory parazitologie   MeSH
• kompetitivní vazba MeSH
• Leishmania fyziologie   MeSH
• lidé MeSH
• metaloendopeptidasy genetika   metabolismus   MeSH
• mutace MeSH
• Phlebotomus parazitologie   MeSH
• protozoální proteiny genetika   metabolismus   MeSH
• Psychodidae parazitologie   MeSH
• stadia vývoje MeSH
• trávicí systém parazitologie   MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

A series of six full-term placentas and umbilical cords were examined using the in situ detection of globotriaosylceramide (Gb3Cer), GM1 ganglioside (GM1), GM3 ganglioside (GM3), cholesterol and caveolin 1. Immunohistochemical study showed uniform distinct staining of the apical membrane of villous capillary endothelial cells for Gb3Cer, GM1, GM3 and cholesterol. There was also a strong signal for caveolin 1. The immunophenotype suggests the presence of caveola-associated raft microdomains. The immunophenotype was almost completely shared with the extravillous intravascular trophoblast in the basal plate. It was absent in the endothelial cells of umbilical vessels and in the capillaries of somatic structures (heart, lung, skeletal muscle and skin) in neonates as well as in adults, including capillaries of the proliferative endometrium. Results of in situ analyses were confirmed by lipid chromatographic analysis of tissue homogenates and by tandem mass spectrometry. Lysosomal Gb3Cer turnover was followed in three placentas including umbilical cords from Fabry disease (α-galactosidase A deficiency). Lysosomal storage was restricted to vascular smooth muscle cells and to endothelial cells of umbilical vessels. Placental villous capillary endothelial cells displaying a strong non-lysosomal staining for Gb3Cer were free of lysosomal storage.

• MeSH
• Fabryho nemoc metabolismus   MeSH
• glykosfingolipidy metabolismus   MeSH
• kapiláry metabolismus   MeSH
• lidé MeSH
• placenta metabolismus   MeSH
• tandemová hmotnostní spektrometrie MeSH
• těhotenství MeSH
• Check Tag
• lidé MeSH
• těhotenství MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Fabry disease (FD) is an X-linked disorder of glycosphingolipid metabolism caused by the deficient activity of alpha-galactosidase A which results in the accumulation of neutral glycosphingolipids in various tissues leading particularly to vasculopathy, cardiomyopathy, neuropathy, and chronic kidney disease. It results in substantial morbidity and premature death in affected patients. Although there are some signs and symptoms suggestive of FD including painful crisis, angiokeratomas, and corneal changes, the majority of FD complications are non-specific (left ventricular hypertrophy, conduction abnormalities, vascular spasms, proteinuria, renal insufficiency), which is why FD still remains largely underdiagnosed. The mechanism by which accumulating glycosphingolipids cause multiorgan disorder is not yet completely understood as it cannot be explained by pure substrate storage. Besides standard therapy of different medical problems in FD patients, specific enzyme replacement therapy has been introduced in the last few years.

• MeSH
• alfa-galaktosidasa metabolismus   terapeutické užití   MeSH
• enzymová substituční terapie MeSH
• Fabryho nemoc komplikace   diagnóza   farmakoterapie   enzymologie   patofyziologie   MeSH
• glykosfingolipidy metabolismus   MeSH
• lidé MeSH
• nemoci cév diagnóza   farmakoterapie   enzymologie   etiologie   patofyziologie   MeSH
• prediktivní hodnota testů MeSH
• výsledek terapie MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• přehledy MeSH

A neuropathologic study of three cases of prosaposin (pSap) deficiency (ages at death 27, 89 and 119 days), carried out in the standard autopsy tissues, revealed a neurolysosomal pathology different from that in the non-neuronal cells. Non-neuronal storage is represented by massive lysosomal accumulation of glycosphingolipids (glucosyl-, galactosyl-, lactosyl-, globotriaosylceramides, sulphatide, and ceramide). The lysosomes in the central and peripheral neurons were distended by pleomorphic non-lipid aggregates lacking specific staining and autofluorescence. Lipid storage was borderline in case 1, and at a low level in the other cases. Neurolysosomal storage was associated with massive ubiquitination, which was absent in the non-neuronal cells and which did not display any immunohistochemical aggresomal properties. Confocal microscopy and cross-correlation function analyses revealed a positive correlation between the ubiquitin signal and the late endosomal/lysosomal markers. We suppose that the neuropathology most probably reflects excessive influx of non-lipid material (either in bulk or as individual molecules) into the neurolysosomes. The cortical neurons appeared to be uniquely vulnerable to pSap deficiency. Whereas in case 1 they populated the cortex, in cases 2 and 3 they had been replaced by dense populations of both phagocytic microglia and astrocytes. We suggest that this massive neuronal loss reflects a cortical neuronal survival crisis precipitated by the lack of pSap. The results of our study may extend the knowledge of the neurotrophic function of pSap, which should be considered essential for the survival and maintenance of human cortical neurons.

• MeSH
• antigeny diferenciační myelomonocytární metabolismus   MeSH
• CD antigeny metabolismus   MeSH
• dítě MeSH
• financování organizované MeSH
• gliový fibrilární kyselý protein metabolismus   MeSH
• glykosfingolipidy metabolismus   MeSH
• lidé MeSH
• lyzozomální nemoci z ukládání metabolismus   patologie   MeSH
• lyzozomy metabolismus   patologie   MeSH
• molekuly buněčné adheze neuronové metabolismus   MeSH
• mozková kůra patologie   MeSH
• neurony patologie   ultrastruktura   MeSH
• novorozenec MeSH
• pitva MeSH
• saposiny fyziologie   nedostatek   MeSH
• ubikvitin metabolismus   MeSH
• Check Tag
• dítě MeSH
• lidé MeSH
• mužské pohlaví MeSH
• novorozenec MeSH
• Publikační typ
• kazuistiky MeSH

Leishmaniases are serious parasitic diseases the etiological organisms of which are transmitted by insect vectors, phlebotominae sand flies. Two sand fly species, Phlebotomus papatasi and P. sergenti, display remarkable specificity for Leishmania parasites they transmit in nature, but many others are broadly permissive to the development of different Leishmania species. Previous studies have suggested that in 'specific' vectors the successful parasite development is mediated by parasite surface glycoconjugates and sand fly lectins, however we show here that interactions involving 'permissive' sand flies utilize another molecules. We did find that the abundant surface glycoconjugate lipophosphoglycan, essential for attachment of Leishmania major in the specific vector P. papatasi, was not required for parasite adherence or survival in the permissive vectors P. arabicus and Lutzomyia longipalpis. Attachment in several permissive sand fly species instead correlated with the presence of midgut glycoproteins bearing terminal N-acetyl-galactosamine and with the occurrence of a lectin-like activity on Leishmania surface. This new binding modality has important implications for parasite transmission and evolution. It may contribute to the successful spreading of Leishmania due to their adaptation into new vectors, namely transmission of L. infantum by Lutzomyia longipalpis; this event led to the establishment of L. infantum/chagasi in Latin America.

• MeSH
• acetylgalaktosamin metabolismus   MeSH
• financování organizované MeSH
• glykoproteiny chemie   metabolismus   MeSH
• glykosfingolipidy metabolismus   MeSH
• hmyz - vektory MeSH
• Leishmania infantum fyziologie   MeSH
• Leishmania klasifikace   růst a vývoj   MeSH
• Phlebotomus klasifikace   parazitologie   MeSH
• Psychodidae klasifikace   parazitologie   MeSH
• trávicí systém parazitologie   MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH