N-glycan on N262 of FGFR3 regulates the intracellular localization and phosphorylation of the receptor.

N-glycosylation and proper processing of N-glycans are required for the function of membrane proteins including cell surface receptors. Fibroblast growth factor receptor (FGFR) is involved in a wide variety of biological processes including embryonic development, osteogenesis, angiogenesis, and cell proliferation. Human FGFR3 contains six potential N-glycosylation sites, however, the roles of glycosylation have not been elucidated. The site-specific profiles of N-glycans of the FGFR3 extracellular domain expressed and secreted by CHO-K1 cells were examined, and glycan occupancies and structures of four sites were determined. The results indicated that most sites were fully occupied by glycans, and the dominant populations were the complex type. By examining single N-glycan deletion mutants of FGFR3, it was found that N262Q mutation significantly increased the population with oligomannose-type N-glycans, which was localized in the endoplasmic reticulum. Protein stability assay suggested that fraction with oligomannose-type N-glycans in the N262Q mutant is more stable than those in the wild type and other mutants. Furthermore, it was found that ligand-independent phosphorylation was significantly upregulated in N262Q mutants with complex type N-glycans. The findings suggest that N-glycans on N262 of FGFR3 affect the intracellular localization and phosphorylation status of the receptor.

Small-cell Lung Carcinoma with Gastrointestinal Pseudo-obstruction as a Paraneoplastic Neurological Syndrome Elicited by an Immune Checkpoint Inhibitor.

Gastrointestinal pseudo-obstruction (GIPO) is a phenotype of the paraneoplastic neurological syndrome (PNS). We herein report a case of small-cell lung carcinoma (SCLC) with GIPO elicited by an immune checkpoint inhibitor (ICI). A 75-year-old man with SCLC developed intractable intestinal obstruction after receiving one course of anticancer drugs (durvalumab, etoposide, and carboplatin). The serum anti-Hu antibody (Hu-Ab) was positive, and the patient was diagnosed with GIPO. Corticosteroid treatment did not improve the GIPO, and the patient died. There are few reports of GIPO after ICI treatment in patients with lung cancer, so a further investigation will be required to elucidate the mechanism by which ICIs elicit PNS. Checking for neuronal antibodies may help identify patients with SCLC who are at risk of developing PNS due to ICI treatment.

N-glycosylation regulates MET processing and signaling.

MET, the receptor for the hepatocyte growth factor (HGF), is strongly associated with resistance to tyrosine kinase inhibitors, key drugs that are used in the therapy of non-small cell lung cancer. MET contains 11 potential N-glycosylation sites, but the site-specific roles of these N-glycans have not been elucidated. We report herein that these N-glycans regulate the proteolytic processing of MET and HGF-induced MET signaling, and that this regulation is site specific. Inhibitors of N-glycosylation were found to suppress the processing and trafficking of endogenous MET in H1975 and EBC-1 lung cancer cells and exogenous MET in CHO-K1 cells. We purified the recombinant extracellular domain of human MET and determined the site-specific N-glycan structures and occupancy using mass spectrometry. The results indicated that most sites were fully glycosylated and that the dominant population was the complex type. To examine the effects of the deletion of N-glycans of MET, we prepared endogenous MET knockout Flp-In CHO cells and transfected them with a series of N-glycan-deletion mutants of MET. The results showed that several N-glycans are implicated in the processing of MET. The findings also suggested that the N-glycans of the SEMA domain of MET positively regulate HGF signaling, and the N-glycans of the region other than the SEMA domain negatively regulate HGF signaling. Processing, cell surface expression, and signaling were significantly suppressed in the case of the all-N-glycan-deletion mutant. The overall findings suggest that N-glycans of MET affect the status and the function of the receptor in a site-specific manner.

Insufficient serum L-ficolin is associated with disease presence and extent of pulmonary Mycobacterium avium complex disease.

BACKGROUND: The incidence of infectious disease caused by nontuberculous mycobacteria is increasing worldwide. Pulmonary Mycobacterium avium complex (MAC) disease is difficult to treat with chemotherapy, and its mechanism of infection, infection route, disease onset, and severity remain unknown. Ficolins are oligomeric defense lectins. L-ficolin plays an important role in innate immunity. This study's aim was to identify L-ficolin's role in patients with pulmonary MAC disease. METHODS: Between April 2011 and September 2017, 61 Japanese patients with pulmonary MAC disease were seen at our hospital. A control group, comprising 30 healthy individuals, without respiratory disease were enrolled in our study. The relationship between serum L-ficolin levels and disease severity was assessed, and L-ficolin's antibacterial role was examined. RESULTS: Serum L-ficolin levels were significantly lower in patients with pulmonary MAC disease than in healthy subjects (1.69 ± 1.27 µg/ml vs. 3.96 ± 1.42 µg/ml; p < 0.001). The cut-off value, based on receiver operating characteristic (ROC) analysis results, was 2.48 µg/ml (area under the curve (AUC) 0.90, sensitivity and specificity 83.6 and 86.7%, respectively). Serum L-ficolin levels were significantly lower in the patients with nodular bronchiectatic type disease compared with the patients with fibrocavitary type disease and were lower in the high-resolution computed tomography high-scoring group compared with low-scoring group. An in vitro analysis showed that purified recombinant L-ficolin bound to M. avium and its major cell wall component, lipoarabinomannan, in a concentration-dependent manner. In addition, recombinant L-ficolin suppressed M. avium growth in a concentration-dependent manner. CONCLUSIONS: Insufficient serum L-ficolin is associated with disease progression in pulmonary MAC disease, and the level of serum L-ficolin is a possible biomarker. TRIAL REGISTRATION: This study is registered with UMIN ( UMIN000022392 ).

[A case of HELLP syndrome at 34w-pregnancy with systemic lupus erythematosus and antiphospholipid antibody syndrome;Importance of measurement of VW factor].

SUMMARY: A 39-year-old woman was diagnosed with Systemic lupus erthymatosus (SLE) in 1993, and initially received 30 mg of prednisolone (PSL) daily as treatment. In 2012, the patient was diagnosed with pregnancy-induced hypertension (PIH) complecated with proteinurea, hypertension and pretibial edema at 24 weeks of gestation. At onset, protein urea was 1.6 g/day and she was given bed rest in the hospital with a protein-restricted and low salt diet, which led to a decrease in protein urea to approximately 1 g/day. At 34 weeks of gestation epigastric pain developed, and laboratory examinations showed liver dysfunction and low platelets. We made a diagnosis of hemolysis, elevated liver enzymes, low platelet (HELLP) syndrome and performed an emergency cesarean procedure. Thereafter blood pressure was elevated, protein urea was 3.2 g/daily, anti-ds-DNA antibody level was elevated and serum C3/C4/CH50 was reduced, thus we gave. plasma exchange therapy, along with immunoadsorption and steroid pulse therapy (methyl-prednisolone 500 mg/daily for 3 days), as well as PSL at 30 mg/day. Overtime clinical symptoms and laboratory data gradually improved. CONCLUSION: Some reports suggest that SLE during pregnancy is a risk factor for hypertension, nephritis, SLE relapse and HELLP syndrome. In the patient, ADAMTS13 activity did not decrease, while there was an increase in VW factor level. We assessed this case was as atypical thrombotic microangiopathy. And herein report HELLP syndrome during pregnancy associated with SLE in our patient.

[Legionnaires' disease with acute renal failure caused by Legionella pneumophilla serogroup 4].

A 77-year-old man who had fever and chest pain was admitted to a neighboring hospital on a diagnosis of pneumonia. Chest X-ray film finding deteriorated despite treatment with 2 g cefotaxime per day. Because of accompanying acute renal failure, he was transferred to our hospital. Hemodialysis with intravenous administration of erythromycin and meropenem resulted in recovery from acute renal failure, and his general condition improved. Because of liver dysfunction, erythromycin was changed to pazufloxacin. Although he was negative for Legionella urinary antigen determined with a rapid assay kit, Binax NOW, his serum titer for Legionella pneumophila serogroup 4 was elevated. Finally, a diagnosis of Legionnaires' disease caused by Legionella pneumophila serogroup 4 was established.

[Two cases of pulmonary aspergillosis successfully treated with combinated micafungin and itraconazole therapy].

We report 2 cases of pulmonary aspergillosis treated successfully by combining micafungin and traconazole. Case 1: A 51-year-old man with hemoptysis and dyspnea on effort treated for pulmonary tuberculosis and aspergillosis was found on chest CT on admission to have a fungus ball in the left upper lobe and increasing consolidation around the cavity of both lung fields. Bronchoscopy proved positive for aspergillus PCR in bronchial lavage. He was diagnosed with chronic necrotizing pulmonary aspergillosis, based on clinical and radiological findings and the positive reaction for aspergillus PCR. He was treated with micafungin alone at first, this proved ineffective, so itraconazole was added, resulting in improvement. Case 2: A 24-year-old woman with stabilized Hodgkin's disease (mixed). She had suffered from a cough and back pain, and chest CT showed increasing consolidation inside and around a giant bulla. She was diagnosed with chronic necrotizing pulmonary aspergillosis, based on isolation for Aspergillus sp. in sputum culture and a positive reaction for Aspergillus antigen in bronchial lavage and Aspergillus antibody in serum. She was treated with the combined micafungin and itraconazole, which rapidly improved symptoms and radiological findings. Pulmonary aspergillosis therapy is often difficult, because delivery of the drug to the infection site is limited and drug tolerance is poor. We found that combination micafungin and itraconazole therapy is tolerable and effective in these cases.

[Results of survey of adult community-acquired pneumonia utilizing flow chart of diagnostic guideline for management of respiratory infections].

We performed a nationwide survey of 1,258 patients to assess the treatment of community-acquired pneumonia in Japan. Cases were classified as bacterial pneumonia in which the causal organism was unknown (Type A) or presumed (Type B), atypical pneumonia (Type C), severe pneumonia (Type D), or pneumonia in certain specific morbid states (Type E). Our objectives were to assess the actual use of antimicrobials and to determine the usefulness of the "Guidelines on Respiratory Infections--Basic Concepts in the Medical Care of Community-Acquired Pneumonia in Adults", developed by the Guideline-Drafting Committee of the Japanese Respiratory Society (JRS), in differentiating these categories of patients. We also hoped to elicit constructive opinions that would contribute to future revisions of these guidelines. The findings showed that pneumonia was classified as "bacterial pneumonia in which the causal organism was unknown" in approximately half (50.2%) of the patients studied. The next most common classification was "severe pneumonia", followed by "atypical pneumonia", "bacterial pneumonia in which the causal organism was presumed", and "pneumonia in certain specific morbid states", in that order. Our results suggest that the JSR guidelines, including the methods for differentiating between bacterial pneumonia and atypical pneumonia, are useful and appropriate, and that antimicrobial agents were generally selected in accordance with the guidelines. We also identified a number of issues to be addressed in future updates of the guidelines, including criteria for physiological assessment, handling of cases in which physical findings and laboratory test results are not in agreement, age-related issues (especially the treatment of patients 65 years of age and older), the differentiation between bacterial pneumonia and atypical pneumonia, the weighing of underlying diseases and complications, and guidelines regarding the use of adjuvant therapy.