Extracellular DJ-1 induces sterile inflammation in the ischemic brain

Inflammation is implicated in the onset and progression of various diseases, including cerebral pathologies. Here, we report that DJ-1, which plays a role within cells as an antioxidant protein, functions as a damage-associated molecular pattern (DAMP) and triggers inflammation if released from dead cells into the extracellular space. We first found that recombinant DJ-1 protein induces the production of various inflammatory cytokines in bone marrow–derived macrophages (BMMs) and dendritic cells (BMDCs). We further identified a unique peptide sequence in the αG and αH helices of DJ-1 that activates Toll-like receptor 2 (TLR2) and TLR4. In the ischemic brain, DJ-1 is released into the extracellular space from necrotic neurons within 24 h after stroke onset and makes direct contact with TLR2 and TLR4 in infiltrating myeloid cells. Although DJ-1 deficiency in a murine model of middle cerebral artery occlusion did not attenuate neuronal injury, the inflammatory cytokine expression in infiltrating immune cells was significantly decreased. Next, we found that the administration of an antibody to neutralize extracellular DJ-1 suppressed cerebral post-ischemic inflammation and attenuated ischemic neuronal damage. Our results demonstrate a previously unknown function of DJ-1 as a DAMP and suggest that extracellular DJ-1 could be a therapeutic target to prevent inflammation in tissue injuries and neurodegenerative diseases.

Intracellular expression of the antioxidant protein DJ-1 has previously been shown to be neuroprotective. This study reveals that extracellularly released DJ-1 from necrotic neurons is a trigger of sterile inflammation that promotes neuronal injury and neurological deficits after ischemic stroke.

In vitro activity of AST-120 that suppresses indole signaling in Escherichia coli, which attenuates drug tolerance and virulence

AST-120 (Kremezin) is used to treat progressive chronic kidney disease (CKD) by adsorbing uremic toxin precursors produced by gut microbiota, such as indole and phenols. In this study, we propose that AST-120 reduces indole level, consequently suppresses indole effects on induction of drug tolerance and virulence in Escherichia coli including enterohaemorrhagic strains. In experiments, AST-120 adsorbed both indole and tryptophan, a precursor of indole production, and led to decreased expression of acrD and mdtEF which encode drug efflux pumps, and elevated glpT, which encodes a transporter for fosfomycin uptake and increases susceptibility to aztreonam, rhodamine 6G, and fosfomycin. AST-120 also decreased the production of EspB, which contributes to pathogenicity of enterohaemorrhagic E. coli (EHEC). Aztreonam, ciprofloxacin, minocycline, trimethoprim, and sulfamethoxazole were also adsorbed by AST-120. However, fosfomycin, in addition to rifampicin, colistin and amikacin were not adsorbed, thus AST-120 can be used together with these drugs for therapy to treat infections. These results suggest another benefit of AST-120, i.e., that it assists antibacterial chemotherapy.

The Tol-Pal System of Uropathogenic Escherichia coli Is Responsible for Optimal Internalization Into and Aggregation Within Bladder Epithelial Cells, Colonization of the Urinary Tract of Mice, and Bacterial Motility

Urinary tracts infection (UTI) caused by uropathogenic Escherichia coli (UPEC) is a common infectious disease. With the shortage of new antimicrobial agents, the increase in UPEC resistance to commonly used drugs, such as fluoroquinolones and β-lactams including carbapenems is a critical issue. UPEC invades urinary tract cells, where it aggregates, and subsequently, forms biofilm-like multicellular colonies termed intracellular bacterial communities (IBCs). This process allows the bacteria to establish infections and so may be a good potential target for new drugs to treat infections. Here, we show that deletion of the tolB gene, encoding a protein of the Tol-Pal system that was originally characterized as a protein complex for colicin uptake and maintenance of the outer membrane, decreases the level of bacterial internalization into and aggregation within cultured bladder epithelial cells and also inhibits the colonization of mice urinary tracts. The tolB mutant also exhibited defective motility because of impaired flagellum syntheses. The fliC and motA mutants, which are non-motile strains, also exhibited lower levels of bacterial internalization and aggregation than their wild-type parent. Additional deletion of tolB in the fliC mutant did not further decrease these, suggesting that the attenuated virulence of the tolB mutant is a result of defective motility. The tolA, tolQ, tolR, and pal mutants that lack other members of the Tol-Pal system also exhibited lower levels of motility and aggregation within bladder epithelial cells compared to their wild-type parent. These combined results suggest another role of the Tol-Pal system, i.e., that it is responsible for optimal internalization, aggregation followed by IBC formation within urinary tract cells, and bacterial motility.

Oxygen Limitation Enhances the Antimicrobial Activity of Fosfomycin in Pseudomonas aeruginosa Following Overexpression of glpT Which Encodes Glycerol-3-Phosphate/Fosfomycin Symporter

Fosfomycin is resurfacing as a "last resort drug" to treat infections caused by multidrug resistant pathogens. This drug has a remarkable benefit in that its activity increases under oxygen-limited conditions unlike other commonly used antimicrobials such as β-lactams, fluoroquinolones and aminoglycosides. Especially, utility of fosfomycin has being evaluated with particular interest to treat chronic biofilm infections caused by Pseudomonas aeruginosa because it often encounters anaerobic situations. Here, we showed that P. aeruginosa PAO1, commonly used in many laboratories, becomes more susceptible to fosfomycin when grown anaerobically, and studied on how fosfomycin increases its activity under anaerobic conditions. Results of transport assay and gene expression study indicated that PAO1 cells grown anaerobically exhibit a higher expression of glpT encoding a glycerol-3-phosphate transporter which is responsible for fosfomycin uptake, then lead to increased intracellular accumulation of the drug. Elevated expression of glpT in anaerobic cultures depended on ANR, a transcriptional regulator that is activated under anaerobic conditions. Purified ANR protein bound to the DNA fragment from glpT region upstream, suggesting it is an activator of glpT gene expression. We found that increased susceptibility to fosfomycin was also observed in a clinical isolate which has a promoted biofilm phenotype and its glpT and anr genes are highly conserved with those of PAO1. We conclude that increased antibacterial activity of fosfomycin to P. aeruginosa under anaerobic conditions is attributed to elevated expression of GlpT following activation of ANR, then leads to increased uptake of the drug.

Three-dimensional changes of noses after transplantation of implant-type tissue-engineered cartilage for secondary correction of cleft lip-nose patients

INTRODUCTION

We have developed an implant-type tissue-engineered cartilage using a poly-l-lactide scaffold. In a clinical study, it was inserted into subcutaneous areas of nasal dorsum in three patients, to correct cleft lip-nose deformity. The aim of this study was to helping evaluation on the efficacy of the regenerative cartilage.

METHODS

3D data of nasal shapes were compared between before and after surgery in computed tomography (CT) images. Morphological and qualitative changes of transplants in the body were also evaluated on MRI, for one year.

RESULTS

The 3D data from CT images showed effective augmentation (>2 mm) of nasal dorsum in almost whole length, observed on the medial line of faces. It was maintained by 1 year post-surgery in all patients, while affected curves of nasal dorsum was not detected throughout the observation period. In magnetic resonance imaging (MRI), the images of transplanted cartilage had been observed until 1 year post-surgery. Those images were seemingly not straight when viewed from the longitudinal plain, and may have shown gentle adaptation to the surrounding nasal bones and alar cartilage tissues.

CONCLUSION

Those findings suggested the potential efficacy of this cartilage on improvement of cleft lip-nose deformity. A clinical trial is now being performed for industrialization.

Cooperative Actions of CRP-cAMP and FNR Increase the Fosfomycin Susceptibility of Enterohaemorrhagic Escherichia coli (EHEC) by Elevating the Expression of glpT and uhpT under Anaerobic Conditions

Bacterial infections to anaerobic site are often hard to be treated because the activity of most of antimicrobials decreases under anaerobic conditions. However, fosfomycin rather provides a greater activity under anaerobic conditions than aerobic conditions. Previously, we found that expression of glpT and uhpT, fosfomycin symporters in enterohaemorrhagic Escherichia coli (EHEC) was upregulated by FNR, a global regulator during the anaerobiosis of the bacterium, which led to increased uptake and susceptibility to this drug. In this study, we showed that expression of glpT and uhpT is induced by CRP-cAMP, the regulator complex under both aerobic and anaerobic conditions. The activity of CRP-cAMP in EHEC was elevated under anaerobic conditions because levels of both CRP and cAMP were higher in the cells when grown anaerobically than those when grown aerobically. Results of expression study using mutants indicated that CRP-cAMP is indispensable for expression of glpT but not uhpT—whereas that of uhpT requires UhpA that is the response regulator composing of two-component system with the sensor kinase, UhpB. The CRP-cAMP protein bound to a region that overlaps RNA polymerase binding site for glpT and region upstream of UhpA binding site for uhpT. FNR bound to a region further upstream of CRP-cAMP binding site on region upstream of the glpT gene. These combined results suggested that increased antibacterial activity of fosfomycin to EHEC under anaerobic conditions is due to activation of FNR and increment of CRP-cAMP activity. Then, FNR enhances the expression of glpT activated by CRP-cAMP while CRP-cAMP and FNR cooperatively aids the action of UhpA to express uhpT to maximum level.

A platform to parallelize planar surfaces and control their spatial separation with nanometer resolution

Parallelizing planar surfaces and manipulating them into close proximity with spatial separation of nanoscale dimensions is critical for probing phenomena such as near-field radiative heat transport and Casimir forces. Here, we report on a novel platform, with an integrated reflected light microscope, that is capable of parallelizing two planar surfaces such that the angular deviation is <6 μrad, while simultaneously allowing control of the gap from 15 μm down to contact with ∼0.15 nm resolution. The capabilities of this platform were verified by using two custom-fabricated micro-devices with planar surfaces, 60 × 60 μm(2) each, whose flatness and surface roughness were experimentally quantified. We first parallelized the two micro-devices by using the developed platform in conjunction with a simple optical approach that relies on the shallow depth of field (∼2 μm) of a long working distance microscope objective. Subsequently, we experimentally tested the parallelism achieved via the optical alignment procedure by taking advantage of electrodes integrated into the micro-devices. Our measurements unambiguously show that the simple depth-of-field based optical approach enables parallelization such that the angular deviation between the two surfaces is within ∼500 μrad. This ensures that the separation between any two corresponding points on the parallel surfaces deviate by ∼30 nm or less from the expected value. Further, we show that improved parallelization can be achieved using the integrated micro-electrodes which enable surface roughness limited parallelization with deviations of ∼5 nm from parallelism.

Gatifloxacin resistance and mutations in gyra after unsuccessful Helicobacter pylori eradication in Japan

A high resistance rate (47.9%) to gatifloxacin (GAT; 8-methoxy fluoroquinolone) in Helicobacter pylori (H. pylori) strains from 48 Japanese patients is observed after unsuccessful H. pylori eradication. A significant association between MICs for GAT equal to or above 1 microg/ml and mutations of the gyrA gene of H. pylori was demonstrated.

Enhanced plasma ghrelin levels in Helicobacter pylori-colonized, interleukin-1-receptor type 1-homozygous knockout (IL-1R1-/-) mice

AIM: Ghrelin is an endogenous ligand for the growth hormone secretagogue receptor, and it plays a role in stimulating the growth hormone secretion, food intake, body weight gain and gastric motility. Eradication of

Helicobacter pylori (H pylori) was shown to be associated with increase of the body weight. On the other hand, H pylori infection evokes the release of gastric IL-1β. The present study was designed to investigate the involvement of the gastric IL-1 signal in the ghrelin dynamics in H pylori-colonized mice.

METHODS: Twelve-week-old female IL-1-receptor type 1-homozygous-knockout mice (IL-1R1^-/-) and their wild-type littermates (WT) were orally inoculated with H pylori (Hp group), while other cohorts received oral inoculation of culture medium (Cont group). Thirteen weeks after the inoculation, the mice were examined. The plasma and stomach ghrelin levels and the gastric preproghrelin mRNA were measured.

RESULTS: Although the WT mice with H pylori infection showed a significantly decreased body weight as compared with that of the animals without H pylori infection, H pylori infection did not influence the body weight of the IL-1R1-knockout (IL-1R1^-/-) mice. In the H pylori-infected IL-1R1^-/- mice, the total and active ghrelin levels in the plasma were significantly increased, and the gastric ghrelin level was decreased. No significant differences were noted in the gastric preproghrelin mRNA expression.

CONCLUSION: Ghrelin secretion triggered by H pylori infection might be suppressed by IL-1β, the release of which is also induced by the infection, resulting in the body weight loss of mice with H pylori infection.

Effect of dietary anti-urease immunoglobulin Y on Helicobacter pylori infection in Mongolian gerbils

BACKGROUND AND AIM

Helicobacter pylori is known to be a major pathogenic factor in the development of gastritis, peptic ulcer disease and gastric cancer. Recently, chicken egg yolk immunoglobulin Y (IgY) has been recognized as an inexpensive antibody source for passive immunization against gastrointestinal infections. The present study was designed to investigate the effect of anti-urease IgY on H. pylori infection in Mongolian gerbils.

METHODS

H. pylori-infected Mongolian gerbils were administered a diet containing anti-urease IgY, with or without famotidine (F). After 10 weeks, bacterial culture and measurement of the gastric mucosal myeloperoxidase (MPO) activity were performed. In a second experiment, another group of gerbils was started on a diet containing F + IgY a week prior to H. pylori inoculation. After 9 weeks, these animals were examined.

RESULTS

In the H. pylori-infected gerbils, there were no significant differences in the level of H. pylori colonization among the different dietary and control groups. However, the MPO activity was significantly decreased in the H. pylori group administered the F + IgY diet compared with that in the H. pylori group administered the IgY, F, or control diet. Furthermore, in the gerbils administered the F + IgY diet prior to the bacterial inoculation, inhibition of H. pylori colonization and suppression of the elevated gastric mucosal MPO activity were observed.

CONCLUSIONS

Oral administration of urease-specific IgY not only inhibited H. pylori disease activity in H. pylori-infected gerbils, but also prevented H. pylori colonization in those not yet infected. These encouraging results may pave the way for a novel therapeutic and prophylactic approach in the management of H. pylori-associated gastroduodenal disease.

Current consensus on the diagnosis and treatment of H. pylori-associated gastroduodenal disease

Helicobacter pylori (H. pylori) is a spiral shaped bacterium that resides in the stomach mucosa. Isolation of H. pylori from the stomach mucosa changed the erstwhile widely held belief that the stomach contains no bacteria and is actually sterile. Once H. pylori is safely ensconced in the mucus, it is able to neutralize the acid in the stomach by elaborating an enzyme called urease. Urease converts urea, of which there is an abundant supply in the stomach (derived from saliva and the gastric juice), into bicarbonate and ammonia, which are strong bases. These bases form a cloud of acid-neutralizing chemicals in the vicinity of the organisms, protecting them from the acid in the stomach. This urea hydrolysis reaction is utilized for the diagnosis of H. pylori infection in the urea breath test (UBT) and the rapid urease test (RUT). In Japan, both invasive tests, such as bacterial culture, histopathology and RUT, and non-invasive tests such as UBT and serology are conducted for the diagnosis of H. pylori infection. For confirming the results of eradication therapy, UBT is considered to be the most sensitive and specific. In order to treat H. pylori infection, a new one-week triple therapy regimen (lansoprazole or omeprazole + amoxicillin + clarithromycin) has been approved for use in patients with peptic ulcer disease in Japan. As for H. pylori eradication in the case of other diseases in which the bacterium has been implicated (e.g., chronic atrophic gastritis, gastric MALT lymphoma, gastric cancer, non-ulcer dyspepsia, chronic urticaria, idiopathic thrombocytopenic purpura (ITP)), further basic and clinical investigation is required.