Role of (p)ppGpp in biofilm formation and expression of filamentous structures in Bordetella pertussis

Bordetella pertussis, the causative agent of whooping cough, is highly adapted to cause human infection. The production of virulence factors, such as adhesins and toxins, is just part of an array of mechanisms by which B. pertussis causes infection. The stringent response is a global bacterial response to nutritional limitation that is mediated by the accumulation of cellular ppGpp and pppGpp [termed together as (p)ppGpp]. Here, we demonstrate that production of (p)ppGpp was controlled by RelA and SpoT proteins in B. pertussis, and that mutation-induced loss of both proteins together caused deficiencies in (p)ppGpp production. The (p)ppGpp-deficient mutants also exhibited defects in growth regulation, decreases in viability under nutritionally limited conditions, increases in susceptibility to oxidative stress and defects in biofilm formation. Analysis of the secreted proteins and the respective transcripts showed that lack of (p)ppGpp led to decreased expression of fim3 and bsp22, which encode a fimbrial subunit and the self-polymerizing type III secretion system tip protein, respectively. Moreover, electron microscopic analysis also indicated that (p)ppGpp regulated the formation of filamentous structures. Most virulence genes - including fim3 and bsp22 - were expressed in the Bvg(+) phase during which the BvgAS two-component system was activated. Although fim3 and bsp22 were downregulated in a (p)ppGpp-deficient mutant, normal expression of fhaB, cyaA and ptxA persisted. Lack of coherence between virulence gene expression and (p)ppGpp production indicated that (p)ppGpp did not modulate the Bvg phase. Taken together, our data indicate that (p)ppGpp may govern an as-yet-unrecognized system that influences B. pertussis pathogenicity.

Sox17 haploinsufficiency results in perinatal biliary atresia and hepatitis in C57BL/6 background mice

Congenital biliary atresia is an incurable disease of newborn infants, of unknown genetic causes, that results in congenital deformation of the gallbladder and biliary duct system. Here, we show that during mouse organogenesis, insufficient SOX17 expression in the gallbladder and bile duct epithelia results in congenital biliary atresia and subsequent acute 'embryonic hepatitis', leading to perinatal death in ~95% of the Sox17 heterozygote neonates in C57BL/6 (B6) background mice. During gallbladder and bile duct development, Sox17 was expressed at the distal edge of the gallbladder primordium. In the Sox17(+/-) B6 embryos, gallbladder epithelia were hypoplastic, and some were detached from the luminal wall, leading to bile duct stenosis or atresia. The shredding of the gallbladder epithelia is probably caused by cell-autonomous defects in proliferation and maintenance of the Sox17(+/-) gallbladder/bile duct epithelia. Our results suggest that Sox17 plays a dosage-dependent function in the morphogenesis and maturation of gallbladder and bile duct epithelia during the late-organogenic stages, highlighting a novel entry point to the understanding of the etiology and pathogenesis of human congenital biliary atresia.

Vascular endothelial adrenomedullin-RAMP2 system is essential for vascular integrity and organ homeostasis

BACKGROUND

Revealing the mechanisms underlying the functional integrity of the vascular system could make available novel therapeutic approaches. We previously showed that knocking out the widely expressed peptide adrenomedullin (AM) or receptor activity-modifying protein 2 (RAMP2), an AM-receptor accessory protein, causes vascular abnormalities and is embryonically lethal. Our aim was to investigate the function of the vascular AM-RAMP2 system directly.

METHODS AND RESULTS

We generated endothelial cell-specific RAMP2 and AM knockout mice (E-RAMP2(-/-) and E-AM(-/-)). Most E-RAMP2(-/-) mice died perinatally. In surviving adults, vasculitis occurred spontaneously. With aging, E-RAMP2(-/-) mice showed severe organ fibrosis with marked oxidative stress and accelerated vascular senescence. Later, liver cirrhosis, cardiac fibrosis, and hydronephrosis developed. We next used a line of drug-inducible E-RAMP2(-/-) mice (DI-E-RAMP2(-/-)) to induce RAMP2 deletion in adults, which enabled us to analyze the initial causes of the aforementioned vascular and organ damage. Early after the induction, pronounced edema with enhanced vascular leakage occurred. In vitro analysis revealed the vascular leakage to be caused by actin disarrangement and detachment of endothelial cells. We found that the AM-RAMP2 system regulates the Rac1-GTP/RhoA-GTP ratio and cortical actin formation and that a defect in this system causes the disruption of actin formation, leading to vascular and organ damage at the chronic stage after the gene deletion.

CONCLUSIONS

Our findings show that the AM-RAMP2 system is a key determinant of vascular integrity and homeostasis from prenatal stages through adulthood. Furthermore, our models demonstrate how endothelial cells regulate vascular integrity and how their dysregulation leads to organ damage.

IL-17 eliminates therapeutic effects of oral tolerance in murine airway allergic inflammation

BACKGROUND

Oral tolerance is a classically used strategy for antigen-specific systemic immunotherapy. However, the roles of IL-17 in modification of oral tolerance are not yet understood.

OBJECTIVE

To define the effects of IL-17 on the modification of oral tolerance, the effects of transfer of Th17 cells, administration of IL-17 or anti-IL-17 antibody (αIL-17Ab) to a murine allergic airway inflammation model were investigated.

METHODS

Mice sensitized to and challenged with OVA, received OVA feeding, followed by OVA challenges. Transfer of Th17 cells, administration of IL-17 or αIL-17Ab were executed during OVA feeding. Airway hyperresponsiveness (AHR), airway inflammation, Th2 cytokine response and lung pathology were assessed.

RESULTS

Administration of IL-17 as well as transfer of Th17 cells aggravated AHR and airway allergic inflammation as compared with the findings in mice subjected to OVA feeding alone, whereas administration of αIL-17Ab ameliorated AHR and airway eosinophilia. The effects of Th17 transfer were presumably attributable to augmentation of endogenous IL-6 production in gut. The number of Foxp3-positive regulatory T (Treg) cells in lungs and Payer's patches was increased in the OVA fed mice, whereas the number of these cells was decreased in the mice subjected to OVA feeding + Th17 cell transfer. Neutralization of IL-6 by monoclonal antibody in the mice subjected to OVA feeding + transfer of Th17 cells restored the effects of oral tolerance.

CONCLUSIONS AND CLINICAL RELEVANCE

These data suggest that IL-17 may inhibit the induction of tolerance to antigen through, at least in part augmenting IL-6 production, thereby suppressing the expansion of Treg cells.

Novel regulation of cardiac metabolism and homeostasis by the adrenomedullin-receptor activity-modifying protein 2 system

Adrenomedullin (AM) was identified as a vasodilating and hypotensive peptide mainly produced by the cardiovascular system. The AM receptor calcitonin receptor-like receptor associates with receptor activity-modifying protein (RAMP), one of the subtypes of regulatory proteins. Among knockout mice ((-/-)) of RAMPs, only RAMP2(-/-) is embryonically lethal with cardiovascular abnormalities that are the same as AM(-/-). This suggests that the AM-RAMP2 system is particularly important for the cardiovascular system. Although AM and RAMP2 are highly expressed in the heart from embryo to adulthood, their analysis has been limited by the embryonic lethality of AM(-/-) and RAMP2(-/-). For this study, we generated inducible cardiac myocyte-specific RAMP2(-/-) (C-RAMP2(-/-)). C-RAMP2(-/-) exhibited dilated cardiomyopathy-like heart failure with cardiac dilatation and myofibril disruption. C-RAMP2(-/-) hearts also showed changes in mitochondrial structure and downregulation of mitochondria-related genes involved in oxidative phosphorylation, β-oxidation, and reactive oxygen species regulation. Furthermore, the heart failure was preceded by changes in peroxisome proliferator-activated receptor-γ coactivator 1α (PGC-1α), a master regulator of mitochondrial biogenesis. Metabolome and matrix-assisted laser desorption/ionization-time-of-flight mass spectrometry (MALDI-TOF-MS) imaging analyses revealed early downregulation of cardiolipin, a mitochondrial membrane-specific lipid. Furthermore, primary-cultured cardiac myocytes from C-RAMP2(-/-) showed reduced mitochondrial membrane potential and enhanced reactive oxygen species production in a RAMP2 deletion-dependent manner. C-RAMP2(-/-) showed downregulated activation of cAMP response element binding protein (CREB), one of the main regulators of mitochondria-related genes. These data demonstrate that the AM-RAMP2 system is essential for cardiac metabolism and homeostasis. The AM-RAMP2 system is a promising therapeutic target of heart failure.

Clinical outcome for EML4-ALK-positive patients with advanced non-small-cell lung cancer treated with first-line platinum-based chemotherapy

BACKGROUND

The EML4-ALK fusion oncogene represents a recently identified molecular target in a subset of patients with non-small-cell lung cancer (NSCLC). Limited data have been available, however, on the outcome of first-line platinum-based chemotherapy in patients with EML4-ALK-positive advanced NSCLC who have not been treated with an ALK kinase inhibitor.

PATIENTS AND METHODS

The efficacy of platinum-based chemotherapy was compared between patients with advanced nonsquamous NSCLC who harbor EML4-ALK and those who harbor EGFR mutations and those with neither molecular abnormality.

RESULTS

Among 200 patients with advanced nonsquamous NSCLC, 18 (9.0%) were positive for EML4-ALK, 31 (15.5%) harbored EGFR mutations, and 151 (75.5%) were wild type for both abnormalities. Platinum-based combination chemotherapy showed similar efficacies in the EML4-ALK, EGFR mutation, and wild-type cohorts in terms of response rate and progression-free survival, and overall survival in the EML4-ALK cohort closely resembled that in the wild-type cohort. Within the EML4-ALK cohort, patients with variants 1 or 3 of the fusion gene were predominant and did not appear to differ in their sensitivity to the platinum-based regimens.

CONCLUSION

Patients with EML4-ALK-positive advanced NSCLC manifest an aggressive clinical course similar to that of those with wild-type tumors if the effective targeted therapy is not instituted.

Detrimental influences of intraluminally-administered sclerotic agents on surrounding tissues and peripheral nerves: an experimental study

The minimally-invasive nature of sclerotherapy makes it one of the first treatment options for venous malformations, although treatment-related complications, such as peripheral nerve paralysis, have been reported in some clinical cases. However, no studies of the aetiology of the detrimental effects of intraluminally-administered sclerotic agents on the surrounding tissues, including the peripheral nerves, have yet been published. This study therefore investigated the influences of intraluminally-administered sclerotic agents on the tissues surrounding the injection site using a newly-developed rat femoral vein model. Using this model, the effects of absolute ethanol, 5% ethanolamine oleate, and 1% polidocanol were compared histologically with those of normal saline controls. Fluorescein isothiocyanate-conjugated agents were administered and the leakage of sclerotic agents through the venous wall was evaluated by fluorescence microscopy. Damage to the adjacent femoral nerve was quantitatively evaluated by counting the numbers of axons in cross-sections. All the sclerotic agents caused vascular wall injuries and leakage into the surrounding tissues. The number of axons in the femoral nerve was significantly reduced following administration of absolute ethanol or 5% ethanolamine oleate, compared with normal saline. The results of this study suggest that sclerotic agents commonly leak out the vascular lumen, and some agents can cause adjacent nerve injury. It is important to be aware of this type of complication of sclerotherapy for venous malformations when selecting appropriate therapeutic interventions.

Plasma protein adsorption to nanofabricated fluorinated polyimide surface

In this article, a series of fluorinated polyimides rubbed at different pressures was prepared, and the plasma protein adsorption on the rubbed polyimide films was evaluated using a micro-bicinchoninic acid protein assay. Interestingly, the amount of plasma protein adsorbed on the polyimide surface strongly depended on the rubbing pressure. The amounts of BSA and Fbg adsorbed on the rubbed polyimide film significantly decreased with an increase in the rubbing pressure. In contrast, the amounts of IgG adsorbed on the rubbed film dramatically increased with an increase in the rubbing pressure. In particular, it is interesting to note that a specific adsorption surface for IgG is formed by the rubbing process. We proposed that the nano-ordered hydrophilic and hydrophobic patternings formed on the top and bottom surfaces on the rubbed fluorinated polyimide film might have a significant influence on the plasma protein adsorption.

Destructive effects of butyrate on the cell envelope of Helicobacter pylori

Helicobacter pylori can be found in the oral cavity and is mostly detected by the use of PCR techniques. Growth of H. pylori is influenced by various factors in the mouth, such as the oral microflora, saliva and other antimicrobial substances, all of which make colonization of the oral cavity by H. pylori difficult. In the present study, we analysed the effect of the cell supernatant of a representative periodontal bacterium Porphyromonas gingivalis on H. pylori and found that the cell supernatant destroyed the H. pylori cell envelope. As P. gingivalis produces butyric acid, we focused our research on the effects of butyrate and found that it significantly inhibited the growth of H. pylori. H. pylori cytoplasmic proteins and DNA were detected in the extracellular environment after treatment with butyrate, suggesting that the integrity of the cell envelope was compromised and indicating that butyrate has a bactericidal effect on H. pylori. In addition, levels of extracellular H. pylori DNA increased following treatment with the cell supernatant of butyric acid-producing bacteria, indicating that the cell supernatant also has a bactericidal effect and that this may be due to its butyric acid content. In conclusion, butyric acid-producing bacteria may play a role in affecting H. pylori colonization of the oral cavity.

Cyclical and patch-like GDNF distribution along the basal surface of Sertoli cells in mouse and hamster testes

Background and Aims

In mammalian spermatogenesis, glial cell line-derived neurotrophic factor (GDNF) is one of the major Sertoli cell-derived factors which regulates the maintenance of undifferentiated spermatogonia including spermatogonial stem cells (SSCs) through GDNF family receptor α1 (GFRα1). It remains unclear as to when, where and how GDNF molecules are produced and exposed to the GFRα1-positive spermatogonia in vivo.

Methodology and Principal Findings

Here we show the cyclical and patch-like distribution of immunoreactive GDNF-positive signals and their close co-localization with a subpopulation of GFRα1-positive spermatogonia along the basal surface of Sertoli cells in mice and hamsters. Anti-GDNF section immunostaining revealed that GDNF-positive signals are mainly cytoplasmic and observed specifically in the Sertoli cells in a species-specific as well as a seminiferous cycle- and spermatogenic activity-dependent manner. In contrast to the ubiquitous GDNF signals in mouse testes, high levels of its signals were cyclically observed in hamster testes prior to spermiation. Whole-mount anti-GDNF staining of the seminiferous tubules successfully visualized the cyclical and patch-like extracellular distribution of GDNF-positive granular deposits along the basal surface of Sertoli cells in both species. Double-staining of GDNF and GFRα1 demonstrated the close co-localization of GDNF deposits and a subpopulation of GFRα1-positive spermatogonia. In both species, GFRα1-positive cells showed a slender bipolar shape as well as a tendency for increased cell numbers in the GDNF-enriched area, as compared with those in the GDNF-low/negative area of the seminiferous tubules.

Conclusion/Significance

Our data provide direct evidence of regionally defined patch-like GDNF-positive signal site in which GFRα1-positive spermatogonia possibly interact with GDNF in the basal compartment of the seminiferous tubules.

Morphological changes in diabetic kidney are associated with increased O-GlcNAcylation of cytoskeletal proteins including α-actinin 4

PURPOSE

The objective of the present study is to identify proteins that change in the extent of the modification with O-linked N-acetylglucosamine (O-GlcNAcylation) in the kidney from diabetic model Goto-Kakizaki (GK) rats, and to discuss the relation between O-GlcNAcylation and the pathological condition in diabetes.

METHODS

O-GlcNAcylated proteins were identified by two-dimensional gel electrophoresis, immunoblotting and peptide mass fingerprinting. The level of O-GlcNAcylation of these proteins was examined by immunoprecipitation, immunoblotting and in situ Proximity Ligation Assay (PLA).

RESULTS

O-GlcNAcylated proteins that changed significantly in the degree of O-GlcNAcylation were identified as cytoskeletal proteins (α-actin, α-tubulin, α-actinin 4, myosin) and mitochondrial proteins (ATP synthase β, pyruvate carboxylase). The extent of O-GlcNAcylation of the above proteins increased in the diabetic kidney. Immunofluorescence and in situ PLA studies revealed that the levels of O-GlcNAcylation of actin, α-actinin 4 and myosin were significantly increased in the glomerulus and the proximal tubule of the diabetic kidney. Immunoelectron microscopy revealed that immunolabeling of α-actinin 4 is disturbed and increased in the foot process of podocytes of glomerulus and in the microvilli of proximal tubules.

CONCLUSION

These results suggest that changes in the O-GlcNAcylation of cytoskeletal proteins are closely associated with the morphological changes in the podocyte foot processes in the glomerulus and in microvilli of proximal tubules in the diabetic kidney. This is the first report to show that α-actinin 4 is O-GlcNAcylated. α-Actinin 4 will be a good marker protein to examine the relation between O-GlcNAcylation and diabetic nephropathy.

Bioinspired choline-like ionic liquids: their penetration ability through cell membranes and application to SEM visualization of hydrous samples

This letter proposes the use of choline-like hydrophilic ionic liquids (ILs) to visualize hydrous samples (e.g., seaweed and other biological or food samples) for scanning electron microscopy (SEM) observation. Some of the water in the samples was successfully replaced with these ILs, which penetrated the cell membranes. The treated samples did not contract much even after drying. The ILs' ionic conductivity decreased the charging of sample surfaces, and good SEM images were obtained.

Effect of probiotic bacterial strains of Lactobacillus, Bifidobacterium, and Enterococcus on enteroaggregative Escherichia coli

The effects of nine probiotic strains of Lactobacillus, Bifidobacterium, and Enterococcus on the growth, adhesion activity, and biofilm formation of enteroaggregative Escherichia coli (EAggEC) were examined. The culture supernatant of the E. faecium strain, with or without pH adjustment to a neutral pH, had a strong bactericidal effect on EAggEC, including induction of membrane damage and cell lysis. Supernatants of the L. casei ss. casei and L. casei ss. rhamnosus strains also had a bactericidal effect on EAggEC, but this activity was abolished by pH adjustment to a neutral pH. No inhibitory effect of the culture supernatants of Bifidobacterium or E. faecalis strains was detected. Adhesion of EAggEC to intestinal epithelial cells was not inhibited by the bacterial strains tested. Two strains of L. casei enhanced EAggEC biofilm formation, which was characterized by increased bacterial proliferation. These results suggest that the three different bacterial species; Lactobacillus, Bifidobacterium, and Enterococcus, have different effects on EAggEC, and that further analysis is required for the practical use of these bacteria as probiotics against EAggEC infection.

Proteomic analysis of two types of exosomes in human whole saliva

Saliva contains a large number of proteins that participate in the protection of oral tissue. Exosomes are small vesicles (30-100 nm in diameter) with an endosome-derived limiting membrane that are secreted by a diverse range of cell types. We have recently demonstrated that exosomes are present in human whole saliva. In this study, we found that whole saliva contained at least two types of exosomes (exosome I and exosome II) that are different in size and protein composition. Proteomic analysis revealed that both types of exosomes contained Alix, Tsg101 and Hsp70, all exosomal markers, immunoglobulin A and polymeric immunoglobulin receptor, whereas they had different protein compositions. Most of dipeptidyl peptidase IV known as CD26 in whole saliva, was present on the exosome II and metabolically active in cleaving chemokines (CXCL11 and CXCL12). Human whole saliva exosomes might participate in the catabolism of bioactive peptides and play a regulatory role in local immune defense in the oral cavity.

Deletion of CDKAL1 affects mitochondrial ATP generation and first-phase insulin exocytosis

Background

A variant of the CDKAL1 gene was reported to be associated with type 2 diabetes and reduced insulin release in humans; however, the role of CDKAL1 in β cells is largely unknown. Therefore, to determine the role of CDKAL1 in insulin release from β cells, we studied insulin release profiles in CDKAL1 gene knockout (CDKAL1 KO) mice.

Principal Findings

Total internal reflection fluorescence imaging of CDKAL1 KO β cells showed that the number of fusion events during first-phase insulin release was reduced. However, there was no significant difference in the number of fusion events during second-phase release or high K⁺-induced release between WT and KO cells. CDKAL1 deletion resulted in a delayed and slow increase in cytosolic free Ca²⁺ concentration during high glucose stimulation. Patch-clamp experiments revealed that the responsiveness of ATP-sensitive K⁺ (K_ATP) channels to glucose was blunted in KO cells. In addition, glucose-induced ATP generation was impaired. Although CDKAL1 is homologous to cyclin-dependent kinase 5 (CDK5) regulatory subunit-associated protein 1, there was no difference in the kinase activity of CDK5 between WT and CDKAL1 KO islets.

Conclusions/Significance

We provide the first report describing the function of CDKAL1 in β cells. Our results indicate that CDKAL1 controls first-phase insulin exocytosis in β cells by facilitating ATP generation, K_ATP channel responsiveness and the subsequent activity of Ca²⁺ channels through pathways other than CDK5-mediated regulation.

In vitro antibacterial activity of Phx-3 against Helicobacter pylori

Phx-3, one of the phenoxazine derivatives, is reported to have inhibitory effect on Mycobacterium species and Chlamydia pneumoniae but not Escherichia coli, Salmonella Typhimurium, Pseudomonas aeruginosa, Staphylococcus aureus, Listeria monocytogenes. The bactericidal activities of Phx-3 against Helicobacter pylori strains have not been assessed. Then, we measured minimum inhibitory concentration of Phx-3 for Helicobacter strains and assessed the morphological and biochemical effects of Phx-3 on H. pylori. In present study, it has shown that H. pylori strains including clarithromycin resistant strain and Helicobacter musterae were killed effectively by the treatment with Phx-3. Furthermore, severe morphological changes such as membrane blebbing and formation of hollows in H. pylori were detected. In addition, induction of heat shock protein 60 was observed. Taken together, Phx-3 has antibacterial activity against Helicobacter pylori.

Increased apoptosis of myoblasts in Drosophila model for the Walker-Warburg syndrome

Walker-Warburg syndrome, a progressive muscular dystrophy, is a severe disease with various kinds of symptoms such as muscle weakness and occasional seizures. The genes of protein O-mannosyltransferases 1 and 2 (POMT1 and POMT2), fukutin, and fukutin-related protein are responsible for this syndrome. In our previous study, we cloned Drosophila orthologs of human POMT1 and POMT2 and identified their activity. However, the mechanism of onset of this syndrome is not well understood. Furthermore, little is known about the behavioral properties of the Drosophila POMT1 and POMT2 mutants, which are called rotated abdomen (rt) and twisted (tw), respectively. First, we performed various kinds of behavioral tests and described in detail the muscle structures by using these mutants. The mutant flies exhibited abnormalities in heavy exercises such as climbing or flight but not in light movements such as locomotion. Defective motor function in mutants appeared immediately after eclosion and was exaggerated with aging. Along with motor function, muscle ultrastructure in the tw mutant was altered, as seen in human patients. We demonstrated that expression of RNA interference (RNAi) for the rt gene and the tw mutant was almost completely lethal and semi-lethal, respectively. Flies expressing RNAi had reduced lifespans. These findings clearly demonstrate that Drosophila POMT mutants are models for human muscular dystrophy. We then observed a high density of myoblasts with an enhanced degree of apoptosis in the tw mutant, which completely lost enzymatic activity. In this paper, we propose a novel mechanism for the development of muscular dystrophy: POMT mutation causes high myoblast density and position derangement, which result in apoptosis, muscle disorganization, and muscle cell defects.

Distribution and function of macrophage galactose-type C-type lectin 2 (MGL2/CD301b): efficient uptake and presentation of glycosylated antigens by dendritic cells

Dendritic cells (DCs) express cell surface lectins that are potentially involved in the recognition, uptake, and presentation of glycosylated foreign substances. A unique calcium-type (C-type) lectin, the macrophage galactose (Gal)-type C-type lectin (MGL/CD301) expressed on DCs, is thought to participate in the recognition of molecules from both altered self and pathogens due to its monosaccharide specificity for Gal and N-acetylgalactosamine (GalNAc). Although mice have two MGL genes, Mgl1 and Mgl2, their distinct roles have not been previously explored. The present report characterizes the properties of MGL2 by examining its distribution and its role in antigen presentation by DCs. We generated an MGL2-specific monoclonal antibody and examined MGL2 expression in tissues by immunohistochemistry and in isolated cells by flow cytometry. The cells reactive with this antibody were shown to be a portion of MGL1-expressing cells, mostly conventional DCs. Internalization of soluble polyacrylamide polymers (PAA) with alpha-GalNAc residues (GalNAc-PAA) by bone marrow-derived DCs (BM-DCs) was mediated by MGL2, as revealed by a comparison of Mgl1(-/-) and Mgl2(-/-) BM-DCs with wild-type BM-DCs. Biotinylated GalNAc-PAA conjugated to streptavidin (SAv) was more efficiently presented to SAv-primed T cells by BM-DCs than beta-N-acetylglucosamine-PAA conjugated to SAv or SAv alone as shown by thymidine uptake and cytokine production. This is the first report that demonstrates the involvement of GalNAc residues in antigen uptake and presentation by DCs that lead to CD4(+) T cell activation.

Pre-embedding electron microscopy methods for glycan localization in chemically fixed mammalian tissue using horseradish peroxidase-conjugated lectin

In histochemistry and cytochemistry, horseradish peroxidase-labeled lectins are often used as probes for the localization of carbohydrates in cells and tissues. In transmission electron microscopy, the most commonly used procedure for detection of carbohydrates is lectin-gold labeling. Horseradish peroxidase catalyzes the formation of insoluble polymerized diaminobenzidine which on exposure to osmium tetroxide forms osmium black, a compound visible in the electron microscope, making horseradish peroxidase an alternative to the more frequently used colloidal gold. This chapter describes a pre-embedding method for carbohydrate localization in which tissue sections are incubated with horseradish peroxidase-conjugated lectin prior to embedding in resin.

A prostacyclin agonist with thromboxane inhibitory activity for airway allergic inflammation in mice

BACKGROUND

ONO-1301 is a novel drug that acts as a prostacyclin agonist with thromboxane A(2) (TxA(2)) synthase inhibitory activity. We investigated the effect of ONO-1301 on development of airway allergic inflammation.

METHODS

Mice sensitized and challenged to ovalbumin (OVA) received ONO-1301, OKY-046 (TxA(2) synthase inhibitor), beraprost, a prostacyclin receptor (IP) agonist, ONO-1301 plus CAY10449 (selective IP antagonist) or vehicle during the challenge period. Twenty-four hours after the OVA challenge, airway hyperresponsiveness (AHR) to methacholine was assessed and bronchoalveolar lavage was performed. Lung specimens were excised for goblet cell staining and analysis of lung dendritic cells (DCs). Bone marrow-derived dendritic cells (BMDCs) were generated, in the presence or absence of drugs, for analysis of DC function.

RESULTS

Mice that received ONO-1301 showed significantly lower AHR, airway eosinophilia, T-helper type 2 cytokine levels, mucus production and lung DCs numbers than vehicle-treated mice. These effects of ONO-1301 were mostly reversed by CAY10449. BMDCs treated with ONO-1301 alone showed lower DC functions, such as expression of costimulatory factors or stimulation to spleen T cells.

CONCLUSIONS

These data suggest that ONO-1301 may suppress AHR and airway allergic inflammation through modulation of DCs, mainly mediated through the IP receptor. This agent may be effective as an anti-inflammatory drug in the treatment of asthma.

Antigenic differences of the scuticociliate Miamiensis avidus from Japan

In Japan and Korea, outbreaks of scuticociliatosis have frequently occurred in Japanese flounder, Paralichthys olivaceus. Morphological observations and small subunit rRNA gene sequences have shown that the causative agent of scuticociliatosis in the flounder is Miamiensis avidus (syn. Philasterides dicentrarchi). In this study, we elucidated the antigenic differences between six Japanese M. avidus isolates as an initial step toward developing an effective vaccine against the disease. Four Japanese flounder isolates (IyoI, Nakajima, JF05To and Mie0301 isolates), one spotted knifejaw, Oplegnathus punctatus, isolate (SK05Kyo), and one ridged-eye flounder, Pleuronichthys cornutus, isolate (RF05To) were subjected to serological analysis. Antisera against IyoI, SK05Kyo, Nakajima and Mie0301 isolates were raised in rabbits and used for immobilization assays and Western blotting. Immobilization assays showed that the six isolates could be divided into three groups, tentatively designated serotype I for IyoI, JF05To, RF05To, SK05Kyo, serotype II for Nakajima and serotype III for Mie0301. Western blotting results supported these three serotypes, with marked similarities in the banding profiles of IyoI, JF05To, RF05To and SK05Kyo isolates, which were distinct from the Nakajima and Mie0301 isolates. Three isolates, IyoI, Nakajima and Mie0301 that were selected as representatives of each serotype, were highly pathogenic to Japanese flounder by experimental infection. Based on these findings, we propose that there are at least three M. avidus serotypes in Japan.

Endoscopic retrograde cholangiography versus peroral cholangioscopy to evaluate intraepithelial tumor spread in biliary cancer

BACKGROUND AND STUDY AIMS

Localized-type bile duct carcinoma (LBDC) is often accompanied by extensive intraepithelial tumor spread (ITS) of 2 cm or more, which makes radical resection more difficult. This retrospective case review compares the diagnostic accuracy of endoscopic retrograde cholangiography (ERC) and peroral cholangioscopy (POCS) to detect ITS beyond the visible LBDC.

PATIENTS AND METHODS

Forty-four consecutive patients with LBDC diagnosed between April 2004 and October 2008 who underwent radical resection with histopathological analysis were included in this study. Extensive ITS was found histopathologically in one-third of the cases (32 %). The outcome parameters were the presence or absence of extensive ITS and the extent of extensive ITS proximal and distal to the main tumor.

RESULTS

In six cases it was not possible to pass the cholangioscope through the tumor sites. ERC correctly identified the presence of extensive ITS in 11/14 cases and did not yield any false-positive results. The three cases in which ERC was negative were all correctly identified by POCS plus biopsy since the cholangioscope could be passed in all three cases. The extent of extensive ITS was correctly diagnosed by ERC alone, ERC with POCS, and ERC with POCS plus mapping biopsy in 22 %, 77 %, and 100 % of cases, respectively.

CONCLUSIONS

The presence of extensive ITS was correctly detected in 80 % of cases by ERC alone. POCS with mapping biopsy provided perfect diagnostic accuracy not only of the presence or absence but also of the extent of extensive ITS. However, POCS has the limitation that the cholangioscope cannot be passed through the tumor sites in approximately 15 % of cases.

Expression of cytokine genes in head kidney and spleen cells of Japanese flounder (Paralichthys olivaceus) infected with Nocardia seriolae

Nocardiosis caused by Nocardia seriolae is an important disease affecting marine fish for which neither control nor preventive measures are available. In this study, we investigated cytokine gene expression in Japanese flounder (Paralichthys olivaceus) infected with N. seriolae to understand the innate immune response. Japanese flounder were challenged with different concentrations of N. seriolae suspensions (0, 1, and 10 mg/L) by immersion for 10min. Mortality was 75% and 95% in fish infected by 1 and 10 mg/L, respectively. The expression of cytokine genes (TNF-alpha, IL-1beta, CC-chemokine) in head kidney and spleen cells to N. seriolae challenge was investigated 2, 24 h, 3 days, and 10 days post-challenge. TNF-alpha expression was significantly increased in spleen after 24 h in 1 mg/L group and in HK after 2 h in 10 mg/L group, but after 24 h and 3 days in 10 mg/L group and after 3 days in 1 mg/L group, it was significantly decreased. IL-1beta expression was significantly up-regulated in spleen after 24 h in 1 mg/l group while in HK only after 2 h in 10 mg/L group before suddenly down-regulated significantly 24 h in 10 mg/L group. The expression of CC-chemokine gene in both spleen and HK was significantly up-regulated in 10 mg/L group 2 h post-challenge and down-regulated in HK after 24 h and after 10 days in 1 mg/L group in spleen, compared to the control group.

Imaging exocytosis of single glucagon-like peptide-1 containing granules in a murine enteroendocrine cell line with total internal reflection fluorescent microscopy

To analyze the exocytosis of glucagon-like peptide-1 (GLP-1) granules, we imaged the motion of GLP-1 granules labeled with enhanced yellow fluorescent protein (Venus) fused to human growth hormone (hGH-Venus) in an enteroendocrine cell line, STC-1 cells, by total internal reflection fluorescent (TIRF) microscopy. We found glucose stimulation caused biphasic GLP-1 granule exocytosis: during the first phase, fusion events occurred from two types of granules (previously docked granules and newcomers), and thereafter continuous fusion was observed mostly from newcomers during the second phase. Closely similar to the insulin granule fusion from pancreatic beta cells, the regulated biphasic exocytosis from two types of granules may be a common mechanism in glucose-evoked hormone release from endocrine cells.

Outer membrane vesicles of Helicobacter pylori TK1402 are involved in biofilm formation

Background

Helicobacter pylori forms biofilms on glass surfaces at the air-liquid interface in in vitro batch cultures; however, biofilms of H. pylori have not been well characterized. In the present study, we analyzed the ability of H. pylori strains to form biofilms and characterized the underlying mechanisms of H. pylori biofilm formation.

Results

Strain TK1402 showed strong biofilm forming ability relative to the other strains in Brucella broth supplemented with 7% FCS. The strong biofilm forming ability of TK1402 is reflected the relative thickness of the biofilms. In addition, outer membrane vesicles (OMV) were detected within the matrix of only the TK1402 biofilms. Biofilm formation was strongly correlated with the production of OMV in this strain. We further observed that strain TK1402 did not form thick biofilms in Brucella broth supplemented with 0.2% β-cyclodextrin. However, the addition of the OMV-fraction collected from TK1402 could enhance biofilm formation.

Conclusion

The results suggested that OMV produced from TK1402 play an important role in biofilm formation in strain TK1402.

Cell-surface arylsulfatase A and B on sinusoidal endothelial cells, hepatocytes, and Kupffer cells in mammalian livers

Arylsulfatase A (ARSA) and B (ARSB) have been regarded as lysosomal enzymes because of their hydrolytic activity on synthetic aromatic substrates and the lysosomal localization of their enzymatic activity. Using sea urchin embryos, we previously demonstrated that the bulk of ARS is located on the cell surface of the epithelium, colocalizing with sulfated polysaccharides, and that it does not exhibit enzymatic activity. To examine whether ARSA and ARSB exist on the cell surface in mammalian tissues, we raised antibodies against ARSA and ARSB and examined immunohistochemically their localization in the liver using light and electron microscopy. Here we show that mammalian ARSA and ARSB exist on the cell surface of sinusoidal endothelial cells, hepatocytes, and sinusoidal macrophages (Kupffer cells), as well as in the lysosome. They are also colocalized with heparan sulfate proteoglycan. These results suggest that ARSA and ARSB also may function in the cell surface of mammals. This is the first report to show cell-surface localization of ARS in mammalian somatic cells. The extracellular localization of ARS will provide new insight for human ARS deficiency disorders, such as metachromatic leukodystrophy and mucopolysaccharidosis VI.

Sea urchin arylsulfatase, an extracellular matrix component, is involved in gastrulation during embryogenesis

Arylsulfatases (Arses) have been regarded as lysosomal enzymes because of their hydrolytic activities on synthetic aromatic substrates and their lysosomal localization of their enzymatic activities. Using sea urchin embryos, we previously demonstrated that the bulk of Hemicentrotus Ars (HpArs) does not exhibit enzyme activity and is located on the apical surface of the epithelial cells co-localizing with sulfated polysaccharides. Here we show that HpArs strongly binds to sulfated polysaccharides and that repression of the synthesis by HpArs-morpholino results in retardation of gastrulation in the sea urchin embryo. Accumulation of HpArs protein and sulfated polysaccharides on the apical surface of the epithelial cells in sea urchin larvae is repressed by treatment with beta-aminopropionitrile (BAPN), suggesting that deposition of HpArs and sulfated polysaccharides is dependent on the crosslinking of proteins such as collagen-like molecules. We suggest that HpArs functions by binding to components of the extracellular matrix.

Calcium loading capacity and morphological changes in mitochondria in an ischemic preconditioned model

The concept of the mitochondrial permeability transition (mPT) has been used to explain cell death induced by calcium deregulation, which is in turn induced by a disruption in the mitochondrial loading capacity of cytosolic calcium (CLC). Whether mitochondria have specific morphologies representing the CLC and the mPT remains controversial. We examined ultrastructural changes in the mitochondria of cultured hippocampal neurons preconditioned with oxygen-glucose deprivation (OGD) for 30 min (30OGD) or 120 min (120OGD). The CLC was then evaluated using simultaneous imaging of the mitochondrial and plasma Ca++ concentrations after the induction of Ca++ influx by the application of glutamate. In the 30OGD group, the CLC increased as the mitochondria rapidly reacted to the increase in plasma Ca++, which was soon cleared. In the 120OGD group, however, the CLC was disturbed because the mitochondrial uptake of Ca was blunted, and the plasma Ca++ was not cleared after glutamate application. We classified the specific morphological changes in the mitochondria according to a previously reported classification. Rounded mitochondria with scarce interior content were observed in the 120OGD group, a model of prolonged lethal OGD, and disruptions in the mitochondrial outer membrane were frequently confirmed, suggesting mPT. The 30OGD group, a model of enhanced CLC in preconditioned neurons, was characterized by round mitochondria with condensed matrices. After glutamate application, the mitochondria became even more rounded with expanded matrices, and outer membrane disruptions were occasionally seen. Our observations suggest that subpopulations of mitochondria with specific morphologies are linked to the CLC and mPT.

Exosome-like vesicles with dipeptidyl peptidase IV in human saliva

Saliva contains a large number of proteins that participate in the protection of oral tissue. We found, for the first time, small vesicles (30-130 nm in diameter) in human whole saliva. Vesicles from saliva were identified by electron microscopy after isolation by gel-filtration on Sepharose CL-4B. They resemble exosomes, which are vesicles with an endosome-derived limiting membrane that are secreted by a diverse range of cell types. We performed a biochemical characterization of these vesicles by amino acid sequence analysis and Western blot analysis. We found that they contain dipeptidyl peptidase IV (DPP IV), galectin-3 and immunoglobulin A, which have potential to influence immune response. The DPP IV in the vesicles was metabolically active in cleaving substance P and glucose-dependent insulinotropic polypeptide to release N-terminal dipeptides. Our results demonstrate that human whole saliva contains exosome-like vesicles; they might participate in the catabolism of bioactive peptides and play a regulatory role in local immune defense in the oral cavity.

The GPCR modulator protein RAMP2 is essential for angiogenesis and vascular integrity

Adrenomedullin (AM) is a peptide involved both in the pathogenesis of cardiovascular diseases and in circulatory homeostasis. The high-affinity AM receptor is composed of receptor activity-modifying protein 2 or 3 (RAMP2 or -3) and the GPCR calcitonin receptor-like receptor. Testing our hypothesis that RAMP2 is a key determinant of the effects of AM on the vasculature, we generated and analyzed mice lacking RAMP2. Similar to AM-/- embryos, RAMP2-/- embryos died in utero at midgestation due to vascular fragility that led to severe edema and hemorrhage. Vascular ECs in RAMP2-/- embryos were severely deformed and detached from the basement membrane. In addition, the abnormally thin arterial walls of these mice had a severe disruption of their typically multilayer structure. Expression of tight junction, adherence junction, and basement membrane molecules by ECs was diminished in RAMP2-/- embryos, leading to paracellular leakage and likely contributing to the severe edema observed. In adult RAMP2+/- mice, reduced RAMP2 expression led to vascular hyperpermeability and impaired neovascularization. Conversely, ECs overexpressing RAMP2 had enhanced capillary formation, firmer tight junctions, and reduced vascular permeability. Our findings in human cells and in mice demonstrate that RAMP2 is a key determinant of the effects of AM on the vasculature and is essential for angiogenesis and vascular integrity.

Protective effects of MnM2Py4P and Mn-salen against small bowel ischemia/reperfusion injury in rats using an in vivo and an ex vivo electron paramagnetic resonance technique with a spin probe

BACKGROUND

Reperfusion of ischemic tissues results in the formation of toxic reactive oxygen species (ROS), such as superoxide anion, hydroxyl radicals, hydroperoxide, and peroxynitrite. ROS are potent oxidizing agents, capable of damaging cellular membranes by lipid peroxidation. In the present study, we applied an in vivo electron paramagnetic resonance (EPR)/spin probe and an ex vivo EPR technique to provide direct evidence of ROS following experimentally induced small bowel ischemia/reperfusion (I/R) injury.

MATERIALS AND METHODS

We used a rat model of small bowel I/R injury to explore the possibility that MnM2Py4P or Mn-salen can prevent the accumulation of ROS species following experimentally induced I/R injury. We examined the ability of MnM2Py4P and Mn-salen to scavenge radicals in living Sprague-Dawley (SD) rats using an in vivo and an ex vivo EPR technique with a spin probe.

RESULTS

The CP decay rates in the MnM2Py4P- and Mn-salen-treated rats were significantly higher than those in the untreated rats and almost equal to those in sham group rats. There were no significant differences between the MnM2Py4P-treated group and the Mn-salen-treated group. Superoxide scavenging activities (SSA) in the MnM2Py4P- and EUK-8-treated group were higher than those in the untreated group and almost equal to the sham group.

CONCLUSION

The present study suggested that the protective effects of MnM2Py4P and Mn-salen against small bowel IR injury were mediated by the inhibition of O2, H2O2, and NO production.