Macrolides have antibiotic and immunomodulatory activities, which may have a favorable effect on the clinical outcome of patients with infections, including influenza. This study aimed to evaluate the effects of combination therapy with an anti-influenza agent, oseltamivir, and a single-dose formulation of azithromycin (AZM), which has been used for influenza-related secondary pneumonia, on influenza patients. The primary endpoint was a change in the expression levels of inflammatory cytokines. Secondary endpoints were the time required for resolution of influenza-related symptoms, incidence of complications, and adverse reactions.
Patients with seasonal influenza were enrolled in this multicenter, open-label, randomized study. Patients were stratified according to the presence of a high risk factor and were randomized to receive combination therapy with oseltamivir plus an extended-release formulation of AZM (combo-group) or oseltamivir monotherapy (mono-group).
We enrolled 107 patients and randomized them into the mono-group (56 patients) or the combo-group (51 patients). All patients were diagnosed with influenza A infection, and none of the patients had comorbid pneumonia. Statistically significant differences were not observed in the expression levels of inflammatory cytokines and chemokines between the 2 groups. The maximum temperature in the combo-group was lower than that in the mono-group on day 3 through day 5 (p = 0.048), particularly on day 4 (p = 0.037).
To our knowledge, this is the first prospective, randomized, clinical trial of oseltamivir and AZM combination therapy for influenza. Although the difference in inflammatory cytokine expression level was not statistically significant, combination therapy showed an early resolution of some symptoms.
Name of registry
University hospital Medical Information Network (UMIN).
Trial Registration no
♦ Objective: Vitamin D plays an important role in calcium homeostasis and is used to treat secondary hyperparathyroidism among dialysis patients. The biologic activity of vitamin D and its analogs is mediated by vitamin D receptor (VDR), which is distributed widely throughout the body. Recent papers have revealed that low vitamin D levels are correlated with severe fibrosis in chronic diseases, including cystic fibrosis and hepatitis. The aim of the present study was to evaluate the protective effects of vitamin D against the progression of peritoneal fibrosis.
♦ Methods: Peritoneal fibrosis was induced by injection of chlorhexidine gluconate (CG) into the peritoneal cavity of mice every other day for 3 weeks. An analog of vitamin D, 22-oxacalcitriol (OCT), was administered subcutaneously daily from initiation of the CG injections. The peritoneal tissue was excised at 3 weeks. Changes in morphology were assessed by hematoxylin and eosin staining. Expression of VDR, alpha smooth muscle actin (as a marker of myofibroblasts), type III collagen, transforming growth factor β(TGF-β), phosphorylated Smad2/3, F4/80 (as a marker of macrophages), and monocyte chemoattractant protein-1 (MCP-1) was examined by immunohistochemistry. Southwestern histochemistry was used to detect activated nuclear factor κB (NF-κB).
♦ Results: In the CG-injected mice, immunohistochemical analysis revealed expression of VDR in mesothelial cells, myofibroblasts, and macrophages in the thickened submesothelial zone. Treatment with OCT significantly prevented peritoneal fibrosis and reduced the accumulation of type III collagen in CG-treated mice. Among the markers of fibrosis, the numbers of myofibroblasts, cells positive for TGF-β, and cells positive for phosphorylated Smad2/3 were significantly decreased in the OCT-treated group compared with the vehicle-treated group. Furthermore, OCT suppressed inflammatory mediators of fibrosis, as shown by the reduced numbers of activated NF-κB cells, macrophages, and MCP-1-expressing cells.
♦ Conclusions: Our results indicate that OCT attenuates peritoneal fibrosis, an effect accompanied by reduced numbers of myofibroblasts, infiltrating macrophages, and TGF-β-positive cells, suggesting that vitamin D has potential as a novel therapeutic agent for preventing peritoneal sclerosis.
Vitamin D; 22-oxacalcitriol; peritoneal fibrosis; TGF-β; MCP-1; NF-κB; southwestern histochemistry
Little is known about the pathophysiology of acute exacerbation (AE) of idiopathic pulmonary fibrosis (IPF). Heat shock protein 47 (HSP47), a collagen-specific molecular chaperone, is essential for biosynthesis and secretion of collagen molecules. Previous studies in experimental animal fibrosis models have shown that downregulation of HSP47 expression reduces collagen production and diminishes fibrosis progression. In this study, serum HSP47 levels were evaluated to elucidate pathogenic differences involving HSP47 between AE-IPF and stable (S)-IPF. Subjects comprised 20 AE-IPF and 33 S-IPF patients. Serum levels of HSP47, Krebs von den Lungen-6 (KL-6), surfactant protein (SP)-A, SP-D, and lactate dehydrogenase (LDH) were measured. Immunohistochemical analysis of lung HSP47 expression was determined in biopsy and autopsy tissues diagnosed as diffuse alveolar damage (DAD) and usual interstitial pneumonia (UIP). Serum levels of HSP47 were significantly higher in AE-IPF than in S-IPF patients, whereas serum levels of KL-6, SP-A, and SP-D did not differ significantly. Receiver operating characteristic curves revealed that HSP47 was superior for discriminating AE-IPF and S-IPF. The cutoff for HSP47 resulting in the highest diagnostic accuracy was 559.4 pg/mL; sensitivity, specificity, and diagnostic accuracy were 100.0 %, 93.9 %, and 96.2 %, respectively. Immunohistochemical analysis revealed that pulmonary HSP47 expression was greater in DAD than UIP tissues. Serum HSP47 was significantly higher in AE-IPF than in S-IPF patients, suggesting that underlying fibrogenic mechanisms involving HSP47 differ in the two conditions.
Acute exacerbation of idiopathic pulmonary fibrosis; Heat shock protein 47; Krebs von den Lungen-6; Surfactant protein A; Surfactant protein D
Biological agents such as tumor necrosis factor-α inhibitors are known to cause mycobacterium infections. Here, we report a disseminated non-tuberculosis case caused by TNF-α inhibitor therapy and a probable paradoxical response to antimycobacterial therapy.
A 68-year-old man with relapsing polychondritis was refractory to glucocorticoid therapy; adalimumab was therefore administered in combination with oral glucocorticoids. Treatment with 40 mg of adalimumab led to rapid improvement of his clinical manifestations. The administration of tacrolimus (1 mg) was started as the dosage of oral glucocorticoids was tapered. However, the patient developed an intermittent high fever and productive cough 15 months after starting adalimumab treatment. A chest computed tomography scan revealed new granular shadows and multiple nodules in both lung fields with mediastinal lymphadenopathy, and Mycobacterium intracellulare was isolated from 2 sputum samples; based on these findings, the patient was diagnosed with non-tuberculosis mycobacteriosis. Tacrolimus treatment was discontinued and oral clarithromycin (800 mg/day), rifampicin (450 mg/day), and ethambutol (750 mg/day) treatment was initiated. However, his condition continued to deteriorate despite 4 months of treatment; moreover, paravertebral and subcutaneous abscesses developed and increased the size of the mediastinal lymphadenopathy. Biopsy of the mediastinal lymphadenopathy and a subcutaneous abscess of the right posterior thigh indicated the presence of Mycobacterium avium complex (MAC), and the diagnosis of disseminated non-tuberculosis mycobacteriosis was confirmed. Despite 9 months of antimycobacterial therapy, the mediastinal lymphadenopathy and paravertebral and subcutaneous abscesses had enlarged and additional subcutaneous abscesses had developed, although microscopic examinations and cultures of sputum and subcutaneous abscess samples yielded negative results. We considered this a paradoxical reaction similar to other reports in tuberculosis patients who had discontinued biological agent treatments, and increased the dose of oral glucocorticoids. The patient’s symptoms gradually improved with this increased dose and his lymph nodes and abscesses began to decrease in size.
Clinicians should consider the possibility of a paradoxical response when the clinical manifestations of non-tuberculosis mycobacteriosis worsen in spite of antimycobacterial therapy or after discontinuation of tumor necrosis factor-α inhibitors. However, additional evidence is needed to verify our findings and to determine the optimal management strategies for such cases.
Non-tuberculosis mycobacteriosis; Mycobacterium intracellulare; Disseminated infection; Relapsing polychondritis; Paradoxical response; Tumor necrosis factor-α inhibitor; Immune reconstitution inflammation syndrome; Non-HIV
Cysteinyl leukotrienes (cys-LTs) are very important factors in the pathophysiology of bronchial asthma. Cys-LT receptor antagonists (LTRAs) decrease allergic airway inflammation. The aim of the present study was to determine the differential effects of LTRAs and corticosteroids on allergic airway inflammation and allergen-specific cytokine production from lymphoid tissues using a murine model of asthma.
Four groups of female BALB/c mice [control (Cont); Dermatophagoides farinae allergen-sensitized (AS); pranlukast (Prl), an LTRA-treated AS; and dexamethasone (Dex)-treated AS] were examined. Lung pathology and cytokine production by prepared mononuclear cells isolated from mediastinal lymph nodes (MLNs) and spleen were compared among these groups.
AS mice exhibited allergic airway inflammation and significant increases in allergen-specific Th1 and Th2 cytokines in MLNs and spleen. Prl-treated mice showed significant attenuation of allergic airway inflammation concomitant with reduction of Th2 cytokines and IFN-γ in MLNs but not in spleen. In contrast, Dex significantly decreased Th1 and Th2 cytokines in MLNs and also decreased them (except IL-13 and IL-2) in spleen.
The inflammatory effects of cys-LTs could differ in lymphoid organs. LTRAs potentially regulate allergic airway inflammation in an organ- and cytokine-specific manner, while systemic corticosteroid shows nonspecific effects.
Leukotriene Antagonists; Lymphoid Tissue; Pranlukast; Asthma
Spontaneous bladder rupture is an extremely rare clinical event that is associated with urinary ascites and apparent acute renal failure. This event is difficult to diagnose clinically, even with advanced techniques such as computed tomography; however, the timely diagnosis of this condition is critical. Here, we report a case of a patient who experienced a spontaneous intraperitoneal bladder rupture 10 years after postoperative pelvic irradiation for the treatment of uterine cancer. In this report of a rare case, we describe the contribution of the appearance of mesothelial cells in the urine to the diagnosis of this condition.
Our patient was a 71-year-old Asian woman who experienced lower abdominal pain and vomiting of two days duration. On admission, abdominal computed tomography showed intraperitoneal fluid collection and her blood tests revealed acute renal failure and hyperkalemia. She underwent hemodialysis and a transurethral catheter was inserted. The transurethral catheter was removed three days after her admission. Four days after the catheter removal, her symptoms recurred and her serum creatinine and blood urea nitrogen levels were elevated. We noted the presence of mesothelial cells in her urine, which led to a diagnosis of intraperitoneal bladder rupture. She underwent surgical repair of her bladder and hyperbaric oxygen therapy, and was discharged after her renal function returned to normal.
Urine analysis is a simple and non-invasive test and we believe that a thorough urine analysis may contribute to the early diagnosis of an intraperitoneal bladder rupture. We think that the findings presented in this case report will significantly enhance our understanding of the etiology of bladder rupture. Moreover, these case findings may help nephrologists and urologists to rapidly diagnose this condition.
Acute renal failure; Mesothelial cells; Spontaneous bladder rupture; Urinary ascites
Acinetobacter baumannii is one of the main pathogens that cause ventilator-associated pneumonia (VAP) and is associated with a high rate of mortality. Little is known about the efficacy of macrolides against A. baumannii. In order to confirm the efficacy of azithromycin (AZM) against VAP caused by multidrug-resistant A. baumannii (MDRAB), we used a mouse model that mimics VAP by placement of a plastic tube in the bronchus. AZM (10 and 100 mg/kg of body weight) was administered subcutaneously every 24 h beginning at 3 h after inoculation. Phosphate-buffered saline was administered as the control. Survival was evaluated over 7 days. At 48 h postinfection, mice were sacrificed and the numbers of viable bacteria in lungs and bronchoalveolar lavage fluid were compared. Histopathological analysis of lung specimens was also performed. The treatment groups displayed significantly longer survival than the control group (P < 0.05). AZM did not have an antimicrobial effect. Histopathological examination of lung specimens indicated that the progression of lung inflammation was prevented in the AZM-treated groups. Furthermore, total cell and neutrophil counts, as well as cytokine levels, in bronchoalveolar lavage fluid were significantly decreased (P < 0.05) in the AZM-treated groups. AZM may have a role for the treatment of VAP with MDRAB because of its anti-inflammatory effects.
Quorum sensing (QS) in Pseudomonas aeruginosa regulates the production of many virulence factors and plays an important role in the pathogenesis of P. aeruginosa infection. N-acyl homoserine lactones (AHL) are major QS signal molecules. Recently, a novel AHL-lactonase enzyme, AiiM, has been identified. The aim of this study was to evaluate the effect of AiiM on the virulence of P. aeruginosa in a mouse model of acute pneumonia. We developed a P. aeruginosa PAO1 strain harboring an AiiM-expressing plasmid. The production of several virulence factors by the AiiM-expressing strain was examined. Mice were intratracheally infected with an AiiM-expressing PAO1 strain. Lung histopathology, bacterial burden, and bronchoalveolar lavage (BAL) fluid were assessed at 24 h postinfection. AiiM expression in PAO1 reduced production of AHL-mediated virulence factors and attenuated cytotoxicity against human lung epithelial cells. In a mouse model of acute pneumonia, AiiM expression reduced lung injury and greatly improved the survival rates. The levels of proinflammatory cytokines and myeloperoxidase activity in BAL fluid were significantly lower in mice infected with AiiM-expressing PAO1. Thus, AiiM can strongly attenuate P. aeruginosa virulence in a mammalian model and is a potential candidate for use as a therapeutic agent against P. aeruginosa infection.
Coinfection with bacteria is a major cause of mortality during influenza epidemics. Recently, Toll-like receptor (TLR) agonists were shown to have immunomodulatory functions. In the present study, we investigated the effectiveness and mechanisms of the new TLR4 agonistic monoclonal antibody UT12 against secondary pneumococcal pneumonia induced by coinfection with influenza virus in a mouse model. Mice were intranasally inoculated with Streptococcus pneumoniae 2 days after influenza virus inoculation. UT12 was intraperitoneally administered 2 h before each inoculation. Survival rates were significantly increased and body weight loss was significantly decreased by UT12 administration. Additionally, the production of inflammatory mediators was significantly suppressed by the administration of UT12. In a histopathological study, pneumonia in UT12-treated mice was very mild compared to that in control mice. UT12 increased antimicrobial defense through the acceleration of macrophage recruitment into the lower respiratory tract induced by c-Jun N-terminal kinase (JNK) and nuclear factor kappaB (NF-κB) pathway-dependent monocyte chemoattractant protein 1 (MCP-1) production. Collectively, these findings indicate that UT12 promoted pulmonary innate immunity and may reduce the severity of severe pneumonia induced by coinfection with influenza virus and S. pneumoniae. This immunomodulatory effect of UT12 improves the prognosis of secondary pneumococcal pneumonia and makes UT12 an attractive candidate for treating severe infectious diseases.
The maintenance of endoplasmic reticulum (ER) homeostasis is critical for numerous aspects of cell physiology. Eukaryotic cells respond to the accumulation of misfolded proteins in the ER (ER stress) by activating the unfolded protein response (UPR), an intracellular signaling pathway that adjusts the folding capacity of the ER. Recent studies of several pathogenic fungi have revealed that the UPR is important for antifungal resistance and virulence; therefore, the pathway has attracted much attention as a potential therapeutic target. While the UPR is highly conserved among eukaryotes, our group recently discovered that the pathogenic yeast Candida glabrata lacks the typical fungal UPR, but possesses alternative mechanisms to cope with ER stress. This review summarizes how C. glabrata responds to ER stress and discusses the impacts of ER quality control systems on antifungal resistance and virulence.
Candida glabrata; endoplasmic reticulum stress; unfolded protein response; regulated Ire1-dependent decay; Ire1; Hac1; calcineurin; Slt2; antifungal resistance; virulence
Daptomycin is inactivated by pulmonary surfactant, but its effectiveness in hematogenous pulmonary infection has been poorly studied. The potential therapeutic application was evaluated in a methicillin-resistant Staphylococcus aureus (MRSA) hematogenous pulmonary infection mouse model. Compared with control results, daptomycin improved survival (P < 0.001) and decreased the number of abscesses and bacteria in the lungs (P < 0.01). Daptomycin may be an effective therapeutic option for MRSA hematogenous pulmonary infection.
Fusobacterium nucleatum is one of the most common anaerobic bacteria in periodontitis and is responsible for several extraoral infections, including respiratory tract diseases. In this study, we examined whether F. nucleatum induces mucin secretion in airway epithelial cells. We also examined the effects of macrolides on F. nucleatum-induced mucus production compared with the effects of other antibiotics that exert anti-anaerobic activities. The production of MUC5AC, the major core protein of mucin secreted from the airway surface epithelium, in bronchial epithelial cells after stimulation with culture supernatants (Sup) of F. nucleatum was analyzed by performing enzyme-linked immunosorbent assay and quantitative RT-PCR. The cell-signaling pathway of F. nucleatum Sup stimulation was also analyzed by Western blotting. For inhibition studies, cells were treated with azithromycin, clarithromycin, clindamycin (CLDM), and metronidazole (MTZ). The F. nucleatum Sup induced NCI-H292 cells to express MUC5AC at both the protein level and the mRNA level in both a time- and dose-dependent manner. Macrolides inhibited F. nucleatum Sup-induced MUC5AC production, while CLDM and MTZ were less effective. F. nucleatum Sup induced the phosphorylation of extracellular signal-regulated kinase 1/2 (ERK1/2), and this induction was suppressed by macrolides. F. nucleatum Sup-induced MUC5AC production was blocked by the ERK pathway inhibitor U0126. F. nucleatum is likely to contribute to excessive mucin production, which suggests that periodontitis may correlate with the pathogenesis of chronic respiratory tract infection. Macrolides seem to reduce this mucin production and might represent an additional means of therapeutic intervention for F. nucleatum respiratory tract infections other than CLDM and MTZ.
Upper respiratory tract infections (URIs) represent the most frequent cause of acute asthma exacerbations. It has yet to be determined whether leukotriene receptor antagonist (LTRA) treatment prevents URI-induced acute asthma exacerbations in adults. The objective of the present study was to evaluate the preventive effects of LTRA treatment on URI-induced acute asthma exacerbations. The incidences of URI alone, acute asthma exacerbation without URI, and URI-induced acute asthma exacerbation were determined retrospectively by analyzing diary and medical records of 321 adult asthmatic patients (mean age, 56.3 ± 17.2 years; male/female ratio, 117:204) over 1 year. Results were compared between patients who had been taking an LTRA (n = 137) and those who had never taken any LTRA (n = 184) during the study periods. Significantly fewer URIs alone and acute asthma exacerbations without URI occurred in patients with than in those without prophylactic daily use of LTRA. LTRA treatment significantly reduced the durations of URIs alone and of total acute asthma exacerbations, as well as the incidence of mild exacerbations of asthma. In contrast, in patients with URI-induced acute asthma exacerbations, LTRA treatment failed to significantly reduce the interval between URI onset and acute asthma exacerbation, as well as the duration and severity of both URIs and acute asthma exacerbations. Use of an LTRA for adult asthmatic patients appears to reduce the incidences of URIs alone and acute asthma exacerbations without URI, but it failed to prevent URI-induced acute asthma exacerbations once a URI occurred.
Acute asthma exacerbation; bronchial asthma; inhaled corticosteroids; inhaled long-acting beta2-agonist; leukotriene receptor antagonist; montelukast; pranlukast; retrospective cohort study; short-acting beta2-agonist; upper respiratory tract infection
Leptin is a hormone mainly produced by white adipose cells, and regulates body fat and food intake by acting on hypothalamus. Leptin receptor is expressed not only in the hypothalamus but in a variety of peripheral tissues, suggesting that leptin has pleiotropic functions. In this study, we investigated the effect of leptin on the progression of peritoneal fibrosis induced by intraperitoneal injection of chlorhexidine gluconate (CG) every other day for 2 or 3 weeks in mice. This study was conducted in male C57BL/6 mice and leptin-deficient ob/ob mice. Peritoneal fluid, blood, and peritoneal tissues were collected 15 or 22 days after CG injection. CG injection increased the level of leptin in serum and peritoneal fluid with thickening of submesothelial compact zone in wild type mice, but CG-injected ob/ob mice attenuate peritoneal fibrosis, and markedly reduced the number of myofibroblasts, infiltrating macrophages, and blood vessels in the thickened submesothelial area. The 2-week leptin administration induced a more thickened peritoneum in the CG-injected C57BL/6 mice than in the PBS group. Our results indicate that an upregulation of leptin appears to play a role in fibrosis and inflammation during peritoneal injury, and reducing leptin may be a therapeutically potential for peritoneal fibrosis.
leptin; peritoneal fibrosis; peritoneal dialysis; angiogenesis; macrophage infiltration
AIM: To explore mutations in serine/threonine kinase 11 (STK11) gene in Peutz-Jeghers syndrome (PJS) with gastrointestinal (GI) hamartomatous polyps.
METHODS: Six Japanese PJS patients in 3 families were enrolled in this study. Each of the cases had hamartomatous polyposis in the gastrointestinal tract, including the small intestine, along with mucocutaneous hyperpigmentation. Narrow-band imaging (NBI)-magnification endoscopy was employed to detect microvascular and microsurface irregularities in the GI lesions. NBI magnification findings could be classified into three groups (type A, type B, or type C). Endoscopic polypectomy was performed using double-balloon enteroscopy or colonoscopy. Genomic DNA was extracted from a whole blood sample from each subject. All of the coding exons of STK11 gene, its boundary regions, and the promoter region containing the polymorphic regions were amplified by polymerase chain reaction, and direct sequencing was performed to assess the germline mutations.
RESULTS: NBI-magnification endoscopic observation could detect the abnormalities in microvessels and microsurface structures of GI polyps. Overall, we found 5 cases of type A and one case without the examination for the gastric polyps, while there were 4 cases of type B and 2 case of type A for the colorectal polyps. Seventy-nine small-bowel and 115 colorectal polyps over 27 sessions for each were resected endoscopically without significant complications. The only delayed complication included the occurrence of bleeding in a case, and this was successfully managed with hemoclips. Resected polyps contained no malignant components. Based on mutation analysis, all 3 cases in Family I exhibited the +658C>T nonsense mutation in exon 5, which resulted in the production of a truncated protein (Q220X). In Family II, a case had -252C>A and -193C>A in the promoter region. In Family III, a case was found to have the +1062C>G (F342L) mutation in exon 8.
CONCLUSION: We found two novel mutations of STK11 in association with PJS. Endoscopic polypectomy of GI polyps in PJS patients appears to be useful to prevent emergency laparotomies and reduce the cancer risk.
Peutz-Jeghers syndrome; Serine/threonine kinase 11; Gastrointestinal hamartomatous polyps; Double-balloon enteroscopy; Narrow-band imaging
Actinomyces graevenitzii is a newly recognized Actinomyces species that is seldom isolated from clinical specimens. A case of multiple pulmonary abscesses mimicking acute pulmonary coccidioidomycosis is described in this study, and the findings indicate that this organism is an opportunistic human pathogen.
This is the first report of a detailed relationship between triazole treatment history and triazole MICs for 154 Aspergillus fumigatus clinical isolates. The duration of itraconazole dosage increased as the itraconazole MIC increased, and a positive correlation was observed (r = 0.5700, P < 0.0001). The number of itraconazole-naïve isolates dramatically decreased as the itraconazole MIC increased, particularly for MICs exceeding 2 μg/ml (0.5 μg/ml versus 2 μg/ml, P = 0.03). We also examined the relationship between cumulative itraconazole usage and the MICs of other azoles. A positive correlation existed between itraconazole dosage period and posaconazole MIC (r = 0.5237, P < 0.0001). The number of itraconazole-naïve isolates also decreased as the posaconazole MIC increased, particularly for MICs exceeding 0.5 μg/ml (0.25 μg/ml versus 0.5 μg/ml, P = 0.004). Conversely, the correlation coefficient obtained from the scattergram of itraconazole usage and voriconazole MICs was small (r = −0.2627, P = 0.001). Susceptibility to three triazole agents did not change as the duration of voriconazole exposure changed. In addition, we carried out detailed analysis, including microsatellite genotyping, for isolates obtained from patients infected with azole-resistant A. fumigatus. We confirmed the presence of acquired resistance to itraconazole and posaconazole due to a G54 substitution in the cyp51A gene for a patient with chronic pulmonary aspergillosis after oral itraconazole therapy. We should consider the possible appearance of azole-resistant A. fumigatus if itraconazole is used for extended periods.
Proper protein folding in the endoplasmic reticulum (ER) is vital in all eukaryotes. When misfolded proteins accumulate in the ER lumen, the transmembrane kinase/endoribonuclease Ire1 initiates splicing of HAC1 mRNA to generate the bZIP transcription factor Hac1, which subsequently activates its target genes to increase the protein-folding capacity of the ER. This cellular machinery, called the unfolded protein response (UPR), is believed to be an evolutionarily conserved mechanism in eukaryotes. In this study, we comprehensively characterized mutant phenotypes of IRE1 and other related genes in the human fungal pathogen Candida glabrata. Unexpectedly, Ire1 was required for the ER stress response independently of Hac1 in this fungus. C. glabrata Ire1 did not cleave mRNAs encoding Hac1 and other bZIP transcription factors identified in the C. glabrata genome. Microarray analysis revealed that the transcriptional response to ER stress is not mediated by Ire1, but instead is dependent largely on calcineurin signaling and partially on the Slt2 MAPK pathway. The loss of Ire1 alone did not confer increased antifungal susceptibility in C. glabrata contrary to UPR-defective mutants in other fungi. Taken together, our results suggest that the canonical Ire1-Hac1 UPR is not conserved in C. glabrata. It is known in metazoans that active Ire1 nonspecifically cleaves and degrades a subset of ER-localized mRNAs to reduce the ER load. Intriguingly, this cellular response could occur in an Ire1 nuclease-dependent fashion in C. glabrata. We also uncovered the attenuated virulence of the C. glabrata Δire1 mutant in a mouse model of disseminated candidiasis. This study has unveiled the unique evolution of ER stress response mechanisms in C. glabrata.
The majority of secretory and transmembrane proteins are structurally matured in the endoplasmic reticulum (ER). The accumulation of misfolded proteins in the ER (ER stress) activates the ER-resident stress transducer Ire1, which has two distinct outputs: the unfolded protein response (UPR) and regulated Ire1-dependent decay (RIDD). The UPR is a transcriptional response to increase the protein folding capacity of the ER. RIDD induces degradation of ER-localized mRNAs to reduce the ER load. To date, the UPR has been believed to be an evolutionarily conserved pathway in almost all eukaryotic species, while RIDD has been found only in metazoans. Recent studies in several pathogenic fungi revealed that the UPR is implicated in antifungal resistance and virulence, and thus it has attracted attention as a therapeutic target. Here, we demonstrate that the important fungal pathogen Candida glabrata has lost the canonical UPR, but instead possesses the RIDD pathway and is relatively tolerant to ER stress. The transcriptional response to ER stress was dependent mainly on calcium signaling mediated by the protein phosphatase calcineurin in C. glabrata. Our results provide novel insights into ER quality control mechanisms and are useful for understanding evolutionary biology and the development of antifungal agents targeting the UPR.
Imatinibmesylate (imatinib) is a small molecule tyrosine kinase inhibitor administered to patients with chronic myelogenous leukemia and gastrointestinal stromal tumor. Although imatinib-associated interstitial lung disease is uncommon, a few cases have been reported so far. However, in all these cases interstitial lung disease developed during the use of imatinib. The present case is the first report of imatinib-induced interstitial lung disease developing after discontinuation of the drug.
A 51-year-old woman was administered oral imatinib for gastrointestinal stromal tumor. Ten weeks later, imatinib was discontinued because of facial edema. On this occasion, chest radiography showed no abnormal findings. However, 2 weeks after discontinuation of imatinib, she developed fever, dry cough, and dyspnea. Chest radiography and computed tomography showed diffuse interstitial infiltrates in both lungs. Examination of bronchoalveolar lavage fluid showed an increased proportion of lymphocytes. Imatinib-induced interstitial lung disease was suspected, because no other cause was evident. After administration of corticosteroids, her clinical condition and chest radiographic findings improved.
We report a unique case of imatinib-induced interstitial lung disease that developed 2 weeks after discontinuation of the drug. Physicians should consider occurrence of imatinib-induced interstitial lung disease even after discontinuation of the drug.
Drug-induced interstitial lung disease; Drug-induced lung injury; Drug induced pneumonitis; Drug lymphocyte-stimulating test; Imatinibmesylate
CC chemokine ligand 20 (CCL20) attracts CC chemokine receptor 6 (CCR6)-expressing cells. Using endoscopic biopsies taken from the gastric antrum of 42 subjects infected with H. pylori and 42 uninfected subjects, mucosal CCL20 mRNA and protein levels were measured by real-time polymerase chain reaction and enzyme-linked immunosorbent assay, respectively. CCL19 mRNA and protein levels, as well as CCL21 mRNA levels, were also measured. The CCL20 mRNA and protein levels were significantly elevated in H. pylori-positive patients and substantially decreased after successful eradication. CCL19 and CCL21 expression levels were comparable in the H. pylori-infected and the uninfected groups. The CCL20 concentrations correlated with the degree of chronic gastritis. Immunohistochemistry and the in vitro infection assay showed that CCL20 was principally produced by the gastric epithelium. CCR6-expressing cells, including CD45RO+ memory T lymphocytes and fascin+-CD1a+ immature dendritic cells, infiltrated close to the CCL20-expressing epithelial cells. The CCL20/CCR6 interaction may be involved in the development of H. pylori-associated gastritis.
CC chemokine ligand 20; CC chemokine receptor 6; H. pylori; Dendritic cells; cag pathogenicity island
We investigated the triazole, amphotericin B, and micafungin susceptibilities of 196 A. fumigatus clinical isolates in Nagasaki, Japan. The percentages of non-wild-type (non-WT) isolates for which MICs of itraconazole, posaconazole, and voriconazole were above the ECV were 7.1%, 2.6%, and 4.1%, respectively. A G54 mutation in cyp51A was detected in 64.2% (9/14 isolates) and 100% (5/5 isolates) of non-WT isolates for itraconazole and posaconazole, respectively. Amphotericin B MICs of ≥2 μg/ml and micafungin minimum effective concentrations (MECs) of ≥16 μg/ml were recorded for two and one isolates, respectively.
Relapsing polychondritis (RP) is a rare inflammatory disease characterized by recurrent chondritis and inflammation of other proteoglycan-rich tissues. An RP patient with co-existing respiratory tract problems could have a poor prognosis.
We reported a case of RP died with recurrent suffocation. At the early stage in this case, unusual deformities of bronchial cartilage were observed. Following systemic corticosteroid therapy, these deformities disappeared, and typical diffuse mucosal edema and dynamic collapse of airways developed.
These bronchoscopic abnormalities could be the early stage of RP.
relapsing polychondritis; suffocation; deformity of bronchial cartilage
Pirfenidone is a novel anti-fibrotic and anti-inflammatory agent that inhibits the progression of fibrosis in animal models and in patients with idiopathic pulmonary fibrosis (IPF). We previously showed that pirfenidone inhibits the over-expression of collagen type I and of heat shock protein (HSP) 47, a collagen-specific molecular chaperone, in human lung fibroblasts stimulated with transforming growth factor (TGF)-β1 in vitro. The increased numbers of HSP47-positive type II pneumocytes as well as fibroblasts were also diminished by pirfenidone in an animal model of pulmonary fibrosis induced by bleomycin. The present study evaluates the effects of pirfenidone on collagen type I and HSP47 expression in the human alveolar epithelial cell line, A549 cells in vitro.
The expression of collagen type I, HSP47 and E-cadherin mRNAs in A549 cells stimulated with TGF-β1 was evaluated by Northern blotting or real-time PCR. The expression of collagen type I, HSP47 and fibronectin proteins was assessed by immunocytochemical staining.
TGF-β1 stimulated collagen type I and HSP47 mRNA and protein expression in A549 cells, and pirfenidone significantly inhibited this process. Pirfenidone also inhibited over-expression of the fibroblast phenotypic marker fibronectin in A549 cells induced by TGF-β1.
We concluded that the anti-fibrotic effects of pirfenidone might be mediated not only through the direct inhibition of collagen type I expression but also through the inhibition of HSP47 expression in alveolar epithelial cells, which results in reduced collagen synthesis in lung fibrosis. Furthermore, pirfenidone might partially inhibit the epithelial-mesenchymal transition.
Pneumocyte; Interstitial pneumonia; Epithelial cell; Epithelial mesenchymal transition; Pulmonary fibrosis
Peramivir is a new neuraminidase inhibitor for intravenous administration that was first introduced in clinical practice in Japan. We conducted a multicenter, open-label, uncontrolled study in children with influenza virus infection ranging in age from ≥28 days to <16 years during the 2009 pandemic A (H1N1) influenza epidemic to evaluate the efficacy, safety, and pharmacokinetics of peramivir in children after intravenous infusion of 10 mg/kg (600 mg maximum) once daily. Among the 106 children (125 days to 15 years old) confirmed to have been infected with the pH1N1 virus by the PCR who were treated with peramivir, the median time to alleviation of symptoms was 29.1 h (95% confidence interval = 22.1 to 32.4), and the proportion of the 106 children who were virus positive was 78.2% on day 2 after the start of treatment and had decreased to 7.1% on day 6. The results of the safety evaluation among 117 patients enrolled in this study showed that adverse events and adverse drug reactions were reported in 62.4 and 29.1%, respectively, of the patients. All of the adverse events and adverse drug reactions resolved or improved rapidly. A population pharmacokinetic analysis was performed on the basis of 297 observed plasma concentration data obtained from 115 children with influenza virus infection. Peramivir exposure in children was within the range of levels within which the efficacy and safety was confirmed in adults, and it is considered that peramivir is clinically and virologically effective and safe in children with pH1N1 virus infection.
Cysteinyl leukotriene receptor antagonist (LTRA) is a widely used medicine for asthma. Cysteinyl leukotrienes (cysLTs) are involved in the regulation of dendritic cell (DC) function. However, the effects of LTRA on DC-related antimicrobial immunity against harmful respiratory pathogens remain unknown. The purpose of this study was to examine the effects of LTRA administered in vivo on DC function against representative respiratory pathogens in vitro. Pulmonary DCs were isolated from four groups of mice: control, mite allergen sensitized (AS), and AS mice treated with the corticosteroid dexamethasone (Dex) or with the LTRA pranlukast (Prl). These DCs were incubated with mite allergen, lipopolysaccharide (LPS), Aspergillus fumigatus, or respiratory syncytial virus (RSV). IL-10 and IL-12 production was then determined. Dex treatment significantly inhibited lipopolysaccharide (LPS)-induced IL-10 and IL-12 production as well as baseline IL-12 production in AS mice. The Prl did not significantly inhibit LPS-induced IL-10 and IL-12 production in AS mice. More importantly, Prl significantly increased IL-10 and IL-12 in AS mice after RSV infection. This study shows that LTRA that is used for asthma potentially up-regulates antimicrobial immunity through modulation of DC function against some respiratory infections without immunosuppression.
Allergic airway inflammation; Aspergillus fumigatus; asthma; corticosteroids; cysteinyl leukotrienes receptor antagonist; cytokines; dendritic cell; Dermatophagoides farinae; lipopolysaccharide; respiratory syncytial virus