Correction to: P2X7R-dependent regulation of glycogen synthase kinase 3ß and claudin-18 in alveolar epithelial type I cells of mice lung.

Correction to: Histochem Cell Biol (2016).

P2X7R-dependent regulation of glycogen synthase kinase 3ß and claudin-18 in alveolar epithelial type I cells of mice lung.

The purinergic receptor P2X7 represents an ATP-gated ionotropic receptor with a selective localization in alveolar epithelial type I cells of the lung. Despite the involvement of the receptor in inflammatory processes of the lung, it is not established whether this receptor plays a specific role in the alveolar epithelial cell biology. There is evidence that P2X7 receptor influences Wnt/ß-catenin signalling pathways in alveolar epithelial cells under conditions of injury. Here, we investigated the expression of GSK-3ß, a potent protein kinase involved in alveolar epithelial barrier functions, and of tight junction molecules occludin, claudin-4 and claudin-18 in wild-type and P2X7-/- mice. Western blot analysis, immunohistochemistry and quantitative real-time RT-PCR revealed a remarkable increase in claudin-18 mRNA and protein in lungs of P2X7-/- mice animals. Furthermore, alveolar epithelial cells from P2X7-/- animals showed decreased levels of GSK-3ß protein and its inactive form GSK-3ß (pS9). Conversely, claudin-18 knockout mice exhibited decreased P2X7 mRNA transcript abundance as measured by mRNA expression microarray and quantitative PCR. Our data are consistent with the hypothesis that P2X7R contributes to alveolar epithelial barrier function through effects on GSK-3ß. Furthermore, these data suggest a potential reciprocal regulation of claudin-18 and P2X7R in the alveolar epithelium.

Early signs of lung fibrosis after in vitro treatment of rat lung slices with CdCl2 and TGF-beta1.

Precision-cut rat lung slices have been employed in combination with an extensive immunohistochemistry of paraffin-embedded slices for monitoring of early pathohistological changes after exposure to CdCl(2)/TGF-beta(1). Three days of CdCl(2) exposure in combination with TGF-beta(1) seem to be sufficient to induce lung injury with alterations similar to changes observed in early lung fibrogenesis: (1) extracellular matrix accumulation and myofibroblast transdifferentiation (Sirius red staining, collagen type IV, alpha-smooth muscle actin), (2) type I cell injury with loss of type I cell antigens (T1alpha antigen, aquaporin-5, RAGE), (3) increased apoptosis of pulmonary cells (active caspase-3, vimentin cleavage product V1 of caspase-9), and (4) activation of microvascular endothelial cells (podocalyxin, caveolin-1). Western blot analysis confirmed the increasing amount of alpha-smooth muscle actin, the loss of T1alpha antigen, and the increase in caveolin-1 immunoreactivity. The explant culture using CdCl(2)/TGF-beta(1) provides a suitable tool for the study of other factors involved in pulmonary pathology including transcription factors, cytokines, and other metabolites involved in early stages of fibrogenesis.

Ganglioside-induced antiganglioside antibodies from a neuropathy patient cross-react with lipopolysaccharides of Campylobacter jejuni associated with Guillain-Barré syndrome.

Antiganglioside serum antibodies from a patient treated with gangliosides were examined for cross-reactivity with lipopolysaccharides (LPSs) of Campylobacter jejuni strains associated with Guillain-Barré syndrome (GBS). The patient had no preceding infection with C. jejuni and developed chronic progressive motor polyneuropathy following parenteral ganglioside treatment. Serum IgG antibodies recognised GM1 and GD1b gangliosides as well as asialo-GM1, and cross-reactivity was observed with LPSs from C. jejuni O:2, O:4, O:19 and O:41. The results give a clear indication that gangliosides and LPSs from C. jejuni serotypes associated with GBS share common epitopes.

Distinct immunoglobulin class and immunoglobulin G subclass patterns against ganglioside GQ1b in Miller Fisher syndrome following different types of infection.

We studied serum antibodies against gangliosides GQ1b and GM1 in 13 patients with Miller Fisher syndrome (MFS) and in 18 patients with Guillain-Barré syndrome (GBS) with cranial nerve involvement. Anti-GQ1b titers were elevated in all patients with MFS cases (immunoglobulin G [IgG] > IgA, IgM), and in 8 of the 18 with GBS. Lower frequencies of increased anti-GM1 titers were observed in MFS patients (3 of 13), as well as in GBS patients (5 of 18). During the course of MFS, anti-GQ1b titers of all Ig classes decreased within 3 weeks after onset. By contrast, anti-GM1 titers (mainly IgM) transiently increased during the course of MFS in five of six patients, suggesting a nonspecific secondary immune response. In patients with MFS following respiratory infections, IgG was the major anti-GQ1b Ig class (six of six patients) and IgG3 was the major subclass (five of six). In contrast, four of five patients with MFS following gastrointestinal infections showed predominance of anti-GQ1b IgA or IgM over IgG and predominance of the IgG2 subclass; anti-GQ1b IgG (IgG3) prevailed in one patient only. These distinct Ig patterns strongly suggest that different infections may trigger different mechanisms of anti-GQ1b production, such as via T-cell-dependent as opposed to T-cell-independent pathways. Thus, the origin of antibodies against GQ1b in MFS may be determined by the type of infectious agent that precipitates the disease.

Antiglycosphingolipid immune responses in neurology. The Vienna experience with isotypes, subclasses, and disease.

IgM, IgG, IgA, and IgG subclass anti-GM1, anti-GQ1b, and anti-asialo-GM1 (anti-GA1) antibodies, respectively, were investigated by ELISA in serum from neurological and other patients. Increased anti-GM1 occurred mostly in approximately 15-35% of the cases without statistical differences; high percentages were found in Guillain-Barré syndrome (GBS) preceded by gastrointestinal infection and multifocal motor neuropathy. Roughly, IgM anti-GM1 was most frequent; however, distinct IgG and IgA reactions were found i.a. in GBS. A particular IgM anti-mono- and disialoganglioside pattern occurred in a patient with sensorimotor neuropathy and paraproteinemia. Anti-GQ1b was elevated in all Miller-Fisher patients, with some prevalence of IgG2 among IgG subclasses. Cross-reactivity of anti-GQ1b was demonstrated with Campylobacter jejuni lipopolysaccharides. Increased anti-GM1 and/or anti-GA1 was more frequent in systemic lupus erythematosus with central nervous system involvement than without. Incidence of anti-GM1 and anti-GA1 in X-adrenoleukodystrophy was relatively high. Although anti-GSL antibodies seem to have limited diagnostic value, studies of isotypes, subclass patterns, and cross-reactivities may lead to further insight into the origin of (auto) immune responses and their immunepathogenetic role in disease.

Serum antibodies against gangliosides and Campylobacter jejuni lipopolysaccharides in Miller Fisher syndrome.

Seven patients with Miller Fisher syndrome (MFS), six in the acute phase and one in the recovery phase, were investigated for serum antibodies against gangliosides and purified lipopolysaccharides (LPS) from different strains of Campylobacter jejuni, including the MFS-associated serotypes O:2 and O:23. Immunoglobulin G antibodies against gangliosides GT1a and GQ1b were found in five of six patients in the acute phase of disease. Three of these patients also displayed antibodies to ganglioside GD2, a finding not previously reported for MFS. All anti-GT1a- and anti-GQ1b-seropositive patients showed antibody binding to C. jejuni LPS, predominantly to O:2 and O:23 LPS. Antibody cross-reactivity between gangliosides GT1a and GQ1b and O:2 and O:23 LPS was demonstrated by adsorption studies. This cross-reactivity between gangliosides and C.jejuni LPS, which is obviously due to oligosaccharide homologies, may be an important pathogenetic factor in the development of MFS after C. jejuni infection.

T-cell-mediated ganglionitis associated with acute sensory neuronopathy.

A 67-year-old man presented with acute painful sensory loss, areflexia, ataxia, urinary retention, and severe constipation and became unable to walk within 2 weeks. He died suddenly 5 weeks after the onset of symptoms. Autopsy revealed widespread inflammation of sensory and autonomic ganglia with immunocytochemical evidence of a CD8+ T cell-mediated cytotoxic attack against ganglion neurons. This observation suggests a novel pathogenetic mechanism of immune-mediated human ganglion cell damage comparable to mechanisms operating in polymyositis.

Immunological and functional localization of both F-type and P-type ATPases in cyanobacterial plasma membranes.

Plasma and thylakoid membranes were prepared and purified from cyanobacteria Anacystis nidulans (Synechococcus PCC6301), Synechocystis PCC6803, and Anabaena PCC7120 grown photoautotrophically in axenic batch cultures and harvested either during early exponential growth (< 1 microliter packed cell mass/ml medium; light-saturated cells) or during linear growth (2-3 microliters packed cell mass/ml medium; light-limited cells). ATPase activities of methanol-activated membranes were determined by measuring (a) total inorganic phosphate released from added ATP, or (b) 32P(i) released from added [gamma-32P] ATP, or (c) NADH oxidation in a coupled ATPase/pyruvate kinase/lactate dehydrogenase system. In addition, membrane proteins were immunoblotted with antibodies raised against chloroplast and mitochondrial F1 coupling factor beta subunits, and Arabidopsis plasma membrane (P-type) ATPase, respectively. The results indicate the presence of (constitutive) P-type ATPase, inhibited by dicyclohexyl carbodiimide (DCCD), o-vanadate and diethylstilbestrol (DES) but insensitive to 7-chloro-4-nitrobenz-2-oxa-1,3-diazole (NBD), and of (inducible) F-type ATPase, inhibited by DCCD and NBD but insensitive to o-vanadate and DES, in the plasma membrane. Thylakoid membranes on the other hand contain F-type ATPase only. Our results emphasize the importance of plasma membrane energization even in obligately phototrophic cyanobacteria.