Reactions of kynurenic acid with hypobromous acid and hypochlorous acid

Kynurenic acid, a tryptophan metabolite, acts as antagonist or agonist of several receptors. Hypobromous acid (HOBr) and hypochlorous acid (HOCl) are generated by eosinophils and neutrophils. At inflammation sites, kynurenic acid may encounter HOBr and HOCl to generate products. When kynurenic acid was incubated with HOBr under neutral conditions, kynurenic acid generated a single product almost exclusively. This was identified as 3-bromokynurenic acid. Kynurenic acid reacted with HOCl, generating two products. The major product was identified as 3-chlorokynurenic acid with its oxidative decarboxylation product, 3-chloro-4-hydroxy-2(1H)-quinolinone as a by-product. Free amino acids suppressed the reactions of kynurenic acid with HOBr and HOCl. Taurine suppressed the HOCl reaction but not the HOBr reaction. An eosinophil peroxidase system containing H₂O₂, NaCl, and NaBr reacted with kynurenic acid, generating 3-bromokynurenic acid under mildly acidic conditions. Although a myeloperoxidase system containing H₂O₂ and NaCl reacted with kynurenic acid to generate 3-chlorokynurenic acid under mildly acidic conditions, the product was altered to 3-bromokynurenic acid by addition of NaBr to the system. These results suggest that 3-bromokynurenic acid and 3-chlorokynurenic acid may be generated from kynurenic acid at inflammation sites in humans, although their formation will be suppressed by coexistent amino acids.     

Increased blood–brain barrier vulnerability to systemic inflammation in an Alzheimer disease mouse model

Behavioral and psychological problems are often observed in patients with dementia such as that associated with Alzheimer disease, and these noncognitive symptoms place an extremely heavy burden on the family and caregivers. Although it is well know that these symptoms often are triggered by infection of peripheral organs, the underlying mechanisms for these pathological conditions are still unclear. In this study, using an Alzheimer amyloid precursor protein (APP)-transgenic mouse, we analyzed behavioral changes and brain inflammatory response induced by peripheral administration of lipopolysaccharide. Application of a unique in vivo microdialysis system revealed that the increase in brain inflammatory cytokine (interleukin-6) level was significantly higher in APP-Tg than in wild-type mice after peripheral lipopolysaccharide injection, which was associated with more severe sickness behaviors. The blood–brain barrier became more permeable in APP-Tg mice during peripherally evoked inflammation, suggesting the increased vulnerability of the blood–brain barrier to inflammation in this animal model of Alzheimer's disease. These findings might provide insight into the pathogenesis of noncognitive symptoms in dementia and a basis to develop new therapeutic treatments for them.     

Acid-electrolyzed functional water-induces Interleukin-1α release from Intracellular Storage Sites in Oral Squamous Cell Carcinoma

The aim of this study was to examine the acid-electrolyzed functional water (FW)-mediated cytokine release in an oral squamous cell carcinoma-derived cell line (OSCC) following treatment with FW. FW is generated by the electrolysis of a sodium chloride solution and accelerate the burn wound healing. To elucidate the underlying mechanisms, the cytokine/chemokine secretion profile of HSC3 cells was examined using a cytokine array. FW treatment significantly induced interleukin (IL)-1α secretion, which was confirmed by enzyme-linked immunosorbent assay. Subsequently, the HSC3 cells were pre-treated with cycloheximide (CHX) for 1 h prior to FW stimulation to determine whether the augmented IL-1α secretion was due to enhanced protein synthesis. CHX pre-treatment did not affect IL-1α secretion suggesting that the secreted IL-1α might have been derived from intracellular storage sites. The amount of IL-1α in the cell lysate of the FW-treated HSC3 cells was significantly lower than that of the non-treated cells. Immunofluorescence staining using a polyclonal antibody against full-length IL-1α revealed a drastic reduction in IL-1α inside the FW- treated cells. IL-1α is synthesized in its precursor form (pIL-1α) and cleaved to produce pro-piece and mature IL-1α (ppIL-1α and mIL-1α) inside the cells. In the present study, only pIL-1α was detected within the HSC3 cells in its resting state. However, FW stimulation resulted in the release of the 33 kDa and two other smaller forms (about 19 kDa) of the protein. These results indicates that FW treatment induces IL-1α secretion, a typical alarmin, from the intracellular storage in OSCC cells.     

Longest neurite‐specific activation of Rap1B in hippocampal neurons contributes to polarity formation through RalA and Nore1A in addition to PI3‐kinase

In a developing nervous system, axon‐dendrite formation is instructed by extrinsic cues, and the mechanism whereby a developing neuron interprets these cues using intracellular signaling is particularly important. Studies using dissociated hippocampal neurons have identified many signaling pathways underlying neuronal polarization. Among the components of these pathways, Rap1B is essential for axon specification in hippocampal cultures. However, spatiotemporal regulation of Rap1B activity in polarizing neurons and how it affects neuronal polarization remain unclear. Herein, we investigated spatiotemporal activity‐change of Rap1B and its target molecules in hippocampal neurons. FRET imaging showed that specific activation of Rap1B was observed at the tip of a future axon. To dissect downstream signaling, we used three effector mutants of Rap1B. Expression of Rap1B‐G12V/E37G and G12V/Y40C mutants resulted in supernumerary axons. The targets of Rap1B‐G12V/E37G were RalA and Nore1A, whereas Rap1B‐G12V/Y40C activated PI3‐kinase. RalA was activated in the tip of stage 3 axons, and RalA‐S28N expression reduced the fraction of neurons with supernumerary axons induced by Rap1B‐G12V/E37G. Furthermore, Nore1A depletion reduced the number of cells without axons. These results indicate that specific activation of Rap1B contributes to neuronal polarization via interaction with RalA and Nore1A in addition to PI3‐kinase.     

Simultaneous, clonally identical T cell expansion in tonsil and synovium in a patient with rheumatoid arthritis and chronic tonsillitis

In some patients with rheumatoid arthritis (RA), the disease improves following tonsillectomy. We describe a 28-year-old woman with treatment-resistant RA and chronic tonsillitis. Initially, her arthritis had been well controlled with methotrexate and corticosteroids, but the RA activity became difficult to control in spite of addition of bucillamine to the treatment regimen and repeated arthrocentesis with infusion of corticosteroid into her swollen joints. Closer examination revealed that the period of exacerbation of her chronic tonsillitis paralleled that of the systemic arthritis, and administration of antibiotics brought transient relief of the systemic symptoms. Her arthritis was ameliorated after successful tonsillectomy and synovectomy, with marked reduction of the serum rheumatoid factor concentration. Analysis of infiltrating T cell clones in tonsil and synovium using T cell receptor V(beta) repertoire and third complementarity-determining region size distribution analysis followed by nucleotide sequencing revealed common clonal T cell expansion in both tissues. This finding suggests the possible involvement of chronic focal infection in refractory RA.     

The resection of non-hepatic intraabdominal recurrence of gastric cancer

BACKGROUND/AIMS: Surgical resection of hepatic or pulmonary metastases from gastrointestinal cancer has been recognized as a curative modality in some patients. However, the role and outcome of the surgical management of a non-hepatic intraabdominal recurrence of gastrointestinal cancer have not been clearly delineated. METHODOLOGY: We treated 5 patients for non-hepatic intraabdominal recurrence of gastric carcinoma surgically. All the resected specimens were microscopically identified as recurrent gastric cancer. Three of 5 patients received postoperative chemotherapy. The clinicopathological findings were analyzed according to the general rules for gastric cancer study. RESULTS: The lymph nodes were dissected for lymph node metastases. Surgical resection of the tumors combined with total gastrectomy, esophagectomy, or colectomy was performed for the local and peritoneal recurrences. All of the recurrent tumors were macroscopically resected with curative states. One patient died of sepsis 54 days after surgery. Three patients died of recurrent gastric cancer: 2 within 1 year of surgery and 1 after 3 years. One patient still survives disease free 3 years and 6 months after the 2nd operation. CONCLUSIONS: Surgical resection for non-hepatic intraabdominal recurrence of gastric cancer is the treatment of choice for selected patients. Surgical resection followed by adjuvant chemotherapy may improve the outcome of these patients.