Method for Preparing Recombinant Galectin-2 Protein without Escherichia coli-Specific Post-translational Modifications.

Galectin-2 (Gal-2) is an animal lectin with specificity for ß-galactosides. It is predominantly expressed and suggested to play a protective function in the gastrointestinal tract; therefore, it can be used as a protein drug. Recombinant proteins have been expressed using Escherichia coli and used to study the function of Gal-2. The recombinant human Gal-2 (hGal-2) protein purified via affinity chromatography after being expressed in E. coli was not completely homogeneous. Mass spectrometry confirmed that some recombinant Gal-2 were phosphogluconoylated. In contrast, the recombinant mouse Gal-2 (mGal-2) protein purified using affinity chromatography after being expressed in E. coli contained a different form of Gal-2 with a larger molecular weight. This was due to mistranslating the original mGal-2 stop codon TGA to tryptophan (TGG). In this report, to obtain a homogeneous Gal-2 protein for further studies, we attempted the following methods: for hGal-2, 1) replacement of the lysine (Lys) residues, which was easily phosphogluconoylated with arginine (Arg) residues, and 2) addition of histidine (His)-tag on the N-terminus of the recombinant protein and cleavage with protease after expression; for mGal-2, 3) changing the stop codon from TGA to TAA, which is commonly used in E. coli. We obtained an almost homogeneous recombinant Gal-2 protein (human and mouse). These results have important implications for using Gal-2 as a protein drug.

Inhibitors of cannabinoid receptor 1 suppress the cellular entry of Lujo virus.

Lujo virus (LUJV), which belongs to Mammarenavirus, family Arenaviridae, has emerged as a pathogen causing severe hemorrhagic fever with high mortality. Currently, there are no effective treatments for arenaviruses, including LUJV. Here, we screened chemical compound libraries of Food and Drug Administration (FDA)-approved drugs and G protein-coupled receptor-associated drugs to identify effective antivirals against LUJV targeting cell entry using a vesicular stomatitis virus-based pseudotyped virus bearing the LUJV envelope glycoprotein (GP). Cannabinoid receptor 1 (CB1) antagonists, such as rimonabant, AM251 and AM281, have been identified as robust inhibitors of LUJV entry. The IC50 of rimonabant was 0.26 and 0.53 µM in Vero and Huh7 cells, respectively. Analysis of the cell fusion activity of the LUJV GP in the presence of CB1 inhibitors revealed that these inhibitors suppressed the fusion activity of the LUJV GP. Moreover, rimonabant, AM251 and AM281 reduced the infectivity of authentic LUJV in vitro, suggesting that the antiviral activity of CB1 antagonists against LUJV is mediated, at least in part, by inhibition of the viral entry, especially, membrane fusion. These findings suggest promising candidates for developing new therapies against LUJV infections.

Peptides Derived from Soybean ß-Conglycinin Induce the Migration of Human Peripheral Polymorphonuclear Leukocytes.

Food-derived peptides have various biological activities. When food proteins are ingested orally, they are digested into peptides by endogenous digestive enzymes and absorbed by the immune cell-rich intestinal tract. However, little is known about the effects of food-derived peptides on the motility of human immune cells. In this study, we aimed to understand the effects of peptides derived from a soybean protein ß-conglycinin on the motility of human peripheral polymorphonuclear leukocytes. We illustrated that MITL and MITLAIPVNKPGR, produced by digestion using in-vivo enzymes (trypsin and pancreatic elastase) of ß-conglycinin, induces the migration of dibutyryl cAMP (Bt2 cAMP)-differentiated human promyelocytic leukemia 60 (HL-60) cells and human polymorphonuclear leukocytes in a dose- and time-dependent manner. This migration was more pronounced in Bt2 cAMP-differentiated HL-60 cells; mRNA expression of formyl peptide receptor (FPR) 1 increased significantly than in all-trans-retinoic acid (ATRA)-differentiated HL-60 cells. This migration was inhibited by tert-butoxycarbonyl (Boc)-MLP, an inhibitor of FPR, and by pretreatment with pertussis toxin (PTX). However, the effect was weak when treated with WRW4, a selective inhibitor of the FPR2. We then demonstrated that MITLAIPVNKPGR induced intracellular calcium responses in human polymorphonuclear leukocytes and Bt2 cAMP-HL60 cells. Furthermore, pre-treatment by fMLP desensitized the calcium response of MITLAIPVNKPGR in these cells. From the above, MITLAIPVNKPGR and MITL derived from soybean ß-conglycinin induced polymorphonuclear leukocyte migration via the FPR1-dependent mechanism. We found chemotactic peptides to human polymorphonuclear leukocytes, which are the endogenous enzyme digests of soybean protein.

Phosphorylation and subcellular localization of human phospholipase A1, DDHD1/PA-PLA1.

Protein phosphorylation is the most common post-translational modification of proteins and functions as a molecular switch for their regulation. This modification is reversibly regulated by protein kinases and phosphatases. In most cases, the phosphorylation of enzymes positively or negatively regulates enzyme activity. However, we found that the phosphorylation of DDHD1 phospholipase A1 (PLA1) did not affect PLA1 activity. Integrated analyses, including phospho-proteomics, Phos-tag SDS-PAGE, PLA1 enzyme assays, and immunofluorescent microscopy, revealed the subcellular localization of DDHD1 without greatly affecting its PLA1 activity. Our findings may contribute to understanding rare clinical cases that concern the implications of protein phosphorylation.

Lysophosphatidylinositol Induced Morphological Changes and Stress Fiber Formation through the GPR55-RhoA-ROCK Pathway.

We previously reported that lysophosphatidylinositol (LPI) functions as an endogenous agonist of GPR55, a novel cannabinoid receptor. However, the physiological roles of LPI-GPR55 have not yet been elucidated in detail. In the present study, we found that LPI induced morphological changes in GPR55-expressing HEK293 cells. LPI induced the cell rounding of GPR55-expressing HEK293 cells but not of empty-vector-transfected cells. LPI also induced the activation of small GTP-binding protein RhoA and increased stress fiber formation in GPR55-expressing HEK293 cells. The inhibition of RhoA and Rho kinase ROCK by the C3 exoenzyme and the ROCK inhibitor reduced LPI-induced cell rounding and stress fiber formation. These results clearly indicated that the LPI-induced morphological changes and the assembly of the cytoskeletons were mediated through the GPR55-RhoA-ROCK pathway.

Phosphorylation of human phospholipase A1 DDHD1 at newly identified phosphosites affects its subcellular localization.

Phospholipase A1 (PLA1) hydrolyzes the fatty acids of glycerophospholipids, which are structural components of the cellular membrane. Genetic mutations in DDHD1, an intracellular PLA1, result in hereditary spastic paraplegia (HSP) in humans. However, the regulation of DDHD1 activity has not yet been elucidated in detail. In the present study, we examined the phosphorylation of DDHD1 and identified the responsible protein kinases. We performed MALDI-TOF MS/MS analysis and Phos-tag SDS-PAGE in alanine-substitution mutants in HEK293 cells and revealed multiple phosphorylation sites in human DDHD1, primarily Ser8, Ser11, Ser723, and Ser727. The treatment of cells with a protein phosphatase inhibitor induced the hyperphosphorylation of DDHD1, suggesting that multisite phosphorylation occurred not only at these major, but also at minor sites. Site-specific kinase-substrate prediction algorithms and in vitro kinase analyses indicated that cyclin-dependent kinase CDK1/cyclin A2 phosphorylated Ser8, Ser11, and Ser727 in DDHD1 with a preference for Ser11 and that CDK5/p35 also phosphorylated Ser11 and Ser727 with a preference for Ser11. In addition, casein kinase CK2α1 was found to phosphorylate Ser104, although this was not a major phosphorylation site in cultivated HEK293 cells. The evaluation of the effects of phosphorylation revealed that the phosphorylation mimic mutants S11/727E exhibit only 20% reduction in PLA1 activity. However, the phosphorylation mimics were mainly localized to focal adhesions, whereas the phosphorylation-resistant mutants S11/727A were not. This suggested that phosphorylation alters the subcellular localization of DDHD1 without greatly affecting its PLA1 activity.

Feasibility study of ultrasound video bronchoscopy for sampling endobronchial lesions.

INTRODUCTION: Endobronchial biopsy using forceps is generally performed with a standard bronchoscope, while a needle is used with an endobronchial ultrasound (EBUS) bronchoscope. An EBUS video bronchoscope, such as the EB-530US instrument (Fujifilm, Tokyo, Japan), provides good visibility and may, therefore, enable both forceps biopsies and needle aspirations to be performed. OBJECTIVES: The aim of this study was to investigate the feasibility of performing forceps biopsies and needle aspirations using the EBUS video bronchoscope for diagnosing endobronchial lesions. METHODS: Seventy patients with suspected endobronchial lesions based on a computed tomography scan were recruited and underwent forceps biopsy using the EB-530US EBUS bronchoscope. If the result of a rapid on-site cytological evaluation was negative, an additional needle aspiration of the same lesion or other target lesions was performed. The primary outcome was the completion rate of bronchoscopy, using only the EBUS bronchoscope without removal. RESULTS: In the 70 patients, forceps biopsies and/or needle aspirations using the EBUS video bronchoscope were performed and completed without removing the EBUS bronchoscope in 67 patients (95.7%). The remaining three patients required the removal of the EBUS bronchoscope from the trachea (blood clot obstruction of the working channel in one patient and change to a thin bronchoscope to sample an EBUS bronchoscope-inaccessible lesion in two others). The EBUS bronchoscope provided diagnostic material in 66 patients (94.3%). One case each of bleeding and pneumonia were observed (1.4%). CONCLUSION: Both forceps biopsy and needle aspiration are feasible using a Fujifilm EB-530US EBUS video bronchoscope.

Potential Interaction between Galectin-2 and MUC5AC in Mouse Gastric Mucus.

Galectins are a group of animal lectins characterized by their specificity for ß-galactosides. Of these, galectin-2 (Gal-2) is predominantly expressed in the gastrointestinal tract. In the current study, we used a mouse gastric mucous fraction to investigate whether Gal-2 is secreted from epithelial cells and identify its potential ligands in gastric mucus. Gal-2 was detected in the mouse gastric mucous fraction and could be eluted from it by the addition of lactose. Affinity chromatography using recombinant mouse galectin-2 (mGal-2)-immobilized adsorbent and subsequent LC-MS/MS identified MUC5AC, one of the major gastric mucin glycoproteins, as a potential ligand of mGal-2. Furthermore, MUC5AC was detected in the mouse gastric mucous fraction by Western blotting, and recombinant mGal-2 was adsorbed to this fraction in a carbohydrate-dependent manner. These results suggested that Gal-2 and MUC5AC in mouse gastric mucus interact in a ß-galactoside-dependent manner, resulting in a stronger barrier structure protecting the mucosal surface.

Solvent-based paclitaxel or nab-paclitaxel for heavily treated relapsed/refractory small cell lung cancer: Retrospective single-institution observational study.

Treatment options for patients with relapsed/refractory small cell lung cancer (R/R SCLC) are limited, and the efficacy of salvage therapies for heavily treated patients should be assessed. Here, we evaluated the efficacy of paclitaxel (PTX) in R/R SCLC patients.A single-institute retrospective chart review was conducted. The primary endpoint was overall survival (OS), whereas the secondary endpoints were progression-free survival (PFS), overall response rate, disease control rate (DCR), and safety.Thirty-one patients (median age, 69 [range, 56-80] years) were analyzed. The median follow-up period was 122 (range, 28-1121) days. The median OS and PFS were 4.4 and 2.2 months, respectively. Adverse events of grade 3 or higher, other than hematological toxicity, were febrile neutropenia and neuropathy. Multivariate analyses identified the following independent predictors of poor OS: performance status and lactate dehydrogenase at the upper limit of normal.PTX monotherapy showed moderate efficacy with acceptable toxicity in heavily treated patients with R/R SCLC patients.

Phase II Study of Weekly Amrubicin for Refractory or Relapsed Non-small Cell Lung Cancer.

BACKGROUND: Amrubicin is usually administered on days 1-3 every 3 weeks by intravenous infusion. However, it causes severe hematological toxicity, especially febrile neutropenia. It was reported that weekly administration confers higher dose intensity, less severe adverse events, and anti-tumor activity that is as effective as that of treatment with a conventional schedule. PATIENTS AND METHODS: Weekly amrubicin was administered at a dose of 60 mg/m2 on days 1 and 8 every 3 weeks. The primary endpoint was overall response rate. RESULTS: A total of 33 patients were enrolled. The overall response rate was 6.1% (95% confidence interval(CI)=0.7-20.2%) and the disease control rate after 2 months was 51.5%. The median progression-free survival was 2.93 months. Febrile neutropenia was observed in only two patients. CONCLUSION: The primary endpoint was not met in this study. However, weekly amrubicin achieved a high disease control rate and good tolerability.

Complex formation of sphingomyelin synthase 1 with glucosylceramide synthase increases sphingomyelin and decreases glucosylceramide levels.

Sphingolipids, including sphingomyelin (SM) and glucosylceramide (GlcCer), are generated by the addition of a polar head group to ceramide (Cer). Sphingomyelin synthase 1 (SMS1) and glucosylceramide synthase (GCS) are key enzymes that catalyze the conversion of Cer to SM and GlcCer, respectively. GlcCer synthesis has been postulated to occur mainly in cis-Golgi, and SM synthesis is thought to occur in medial/trans-Golgi; however, SMS1 and GCS are known to partially co-localize in cisternae, especially in medial/trans-Golgi. Here, we report that SMS1 and GCS can form a heteromeric complex, in which the N terminus of SMS1 and the C terminus of GCS are in close proximity. Deletion of the N-terminal sterile α-motif of SMS1 reduced the stability of the SMS1-GCS complex, resulting in a significant reduction in SM synthesis in vivo In contrast, chemical-induced heterodimerization augmented SMS1 activity, depending on an increase in the amount and stability of the complex. Fusion of the SMS1 N terminus to the GCS C terminus via linkers of different lengths increased SM synthesis and decreased GlcCer synthesis in vivo These results suggest that formation of the SMS1-GCS heteromeric complex increases SM synthesis and decreases GlcCer synthesis. Importantly, this regulation of relative Cer levels by the SMS1-GCS complex was confirmed by CRISPR/Cas9-mediated knockout of SMS1 or GCS combined with pharmacological inhibition of Cer transport protein in HEK293T cells. Our findings suggest that complex formation between SMS1 and GCS is part of a critical mechanism controlling the metabolic fate of Cer in the Golgi.

Coenzyme-A-Independent Transacylation System; Possible Involvement of Phospholipase A2 in Transacylation.

The coenzyme A (CoA)-independent transacylation system catalyzes fatty acid transfer from phospholipids to lysophospholipids in the absence of cofactors such as CoA. It prefers to use C20 and C22 polyunsaturated fatty acids such as arachidonic acid, which are esterified in the glycerophospholipid at the sn-2 position. This system can also acylate alkyl ether-linked lysophospholipids, is involved in the enrichment of arachidonic acid in alkyl ether-linked glycerophospholipids, and is critical for the metabolism of eicosanoids and platelet-activating factor. Despite their importance, the enzymes responsible for these reactions have yet to be identified. In this review, we describe the features of the Ca2+-independent, membrane-bound CoA-independent transacylation system and its selectivity for arachidonic acid. We also speculate on the involvement of phospholipase A2 in the CoA-independent transacylation reaction.

Carboxyl-terminal Tail-mediated Homodimerizations of Sphingomyelin Synthases Are Responsible for Efficient Export from the Endoplasmic Reticulum.

Sphingomyelin synthase (SMS) is the key enzyme for cross-talk between bioactive sphingolipids and glycerolipids. In mammals, SMS consists of two isoforms: SMS1 is localized in the Golgi apparatus, whereas SMS2 is localized in both the Golgi and plasma membranes. SMS2 seems to exert cellular functions through protein-protein interactions; however, the existence and functions of quaternary structures of SMS1 and SMS2 remain unclear. Here we demonstrate that both SMS1 and SMS2 form homodimers. The SMSs have six membrane-spanning domains, and the N and C termini of both proteins face the cytosolic side of the Golgi apparatus. Chemical cross-linking and bimolecular fluorescence complementation revealed that the N- and/or C-terminal tails of the SMSs were in close proximity to those of the other SMS in the homodimer. Homodimer formation was significantly decreased by C-terminal truncations, SMS1-ΔC22 and SMS2-ΔC30, indicating that the C-terminal tails of the SMSs are primarily responsible for homodimer formation. Moreover, immunoprecipitation using deletion mutants revealed that the C-terminal tail of SMS2 mainly interacted with the C-terminal tail of its homodimer partner, whereas the C-terminal tail of SMS1 mainly interacted with a site other than the C-terminal tail of its homodimer partner. Interestingly, homodimer formation occurred in the endoplasmic reticulum (ER) membrane before trafficking to the Golgi apparatus. Reduced homodimerization caused by C-terminal truncations of SMSs significantly reduced ER-to-Golgi transport. Our findings suggest that the C-terminal tails of SMSs are involved in homodimer formation, which is required for efficient transport from the ER.

Rigid bronchoscopic intervention for endobronchial metastasis of renal cell carcinoma.

BACKGROUND: Renal cell carcinoma is one of the major endobronchial metastases, and it occasionally causes life-threatening airway obstruction. Rigid bronchoscopy is useful as a palliative intervention; however, its utility for metastatic renal cell carcinoma has not been elucidated. The purpose of this study was to evaluate the safety and efficacy of rigid bronchoscopic treatment for endobronchial metastasis of renal cell carcinoma. METHODS: Among 550 patients who underwent rigid bronchoscopic intervention at a single center from January 2005 to June 2015, 9 with metastatic renal cell carcinoma were retrospectively reviewed. Procedures were performed with rigid and flexible bronchoscopes under general anesthesia. RESULTS: In total, 20 procedures were performed on 9 patients who underwent stent implantation. Bleeding was observed in 12 (60%) procedures while severe hypoxia was observed in 2 (10%). The required amount of supplemental oxygen successfully decreased after all the 10 procedures (100%) in patients who previously needed it. Median survival after the first procedure was of 260 days (range, 63-913 days). CONCLUSIONS: Rigid bronchoscopic intervention for endobronchial metastasis of renal cell carcinoma is feasible with safety and effectiveness for palliation of airway obstruction, if one prepares sufficiently for massive intraoperative bleeding.

Endobronchial ultrasound-guided transbronchial needle aspiration is useful as an initial procedure for the diagnosis of lymphoma.

BACKGROUND: The usefulness of endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) for evaluating hilar, mediastinal and central parenchymal lesions has been well established. However, its utility for diagnosing lymphoma is controversial. The aim of this study was to evaluate the diagnostic utility of EBUS-TBNA for the definitive diagnosis of de novo lymphoma with subtype classification. METHODS: Patients with lymphoma who underwent EBUS-TBNA for diagnostic purposes at a single institution between March 2004 and May 2013 were retrospectively reviewed. RESULTS: Of the 971 patients who underwent EBUS-TBNA during the study period, 19 patients, who did not have a previous history of lymphoma, had a final diagnosis of lymphoma. EBUS-TBNA provided a diagnosis accompanied with subtype classification in 6 patients (32%), a suspicious but not definitive classification in 10 patients (53%), and a negative classification in 3 patients (16%). Immunohistochemical staining for definitive diagnosis was performed in 15 of 16 patients (94%), with suspicious results from routine hematoxylin and eosin staining. No procedure-related complications occurred. CONCLUSIONS: EBUS-TBNA is a useful initial diagnostic procedure, aiding decisions for the management of patients with suspected lymphoma, even though the sensitivity of EBUS-TBNA for diagnosing lymphoma with subtype classification was lower than previously reported.

A correlation of reactive oxygen species accumulation by depletion of superoxide dismutases with age-dependent impairment in the nervous system and muscles of Drosophila adults.

The theory that accumulation of reactive oxygen species (ROS) in internal organs is a major promoter of aging has been considered negatively. However, it is still controversial whether overexpression of superoxide dismutases (SODs), which remove ROS, extends the lifespan in Drosophila adults. We examined whether ROS accumulation by depletion of Cu/Zn-SOD (SOD1) or Mn-SOD (SOD2) influenced age-related impairment of the nervous system and muscles in Drosophila. We confirmed the efficient depletion of Sod1 and Sod2 through RNAi and ROS accumulation by monitoring of ROS-inducible gene expression. Both RNAi flies displayed accelerated impairment of locomotor activity with age and shortened lifespan. Similarly, adults with nervous system-specific depletion of Sod1 or Sod2 also showed reduced lifespan. We then found an accelerated loss of dopaminergic neurons in the flies with suppressed SOD expression. A half-dose reduction of three pro-apoptotic genes resulted in a significant suppression of the neuronal loss, suggesting that apoptosis was involved in the neuronal loss caused by SOD silencing. In addition, depletion of Sod1 or Sod2 in musculature is also associated with enhancement of age-related locomotion impairment. In indirect flight muscles from SOD-depleted adults, abnormal protein aggregates containing poly-ubiquitin accumulated at an early adult stage and continued to increase as the flies aged. Most of these protein aggregates were observed between myofibril layers. Moreover, immuno-electron microscopy indicated that the aggregates were predominantly localized in damaged mitochondria. These findings suggest that muscular and neuronal ROS accumulation may have a significant effect on age-dependent impairment of the Drosophila adults.

Transbronchial vs transesophageal needle aspiration using an ultrasound bronchoscope for the diagnosis of mediastinal lesions: a randomized study.

BACKGROUND: The purpose of this study was to compare the tolerance, efficacy, and safety of endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) with transesophageal endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) with an endobronchial ultrasound scope for the first pathologic diagnosis of lesions accessible by both procedures. METHODS: Patients who had lesions accessible by both EBUS-TBNA and EUS-FNA were enrolled and were randomized to undergo either procedure. Patients quantified tolerance, and operators charted the quality of examination using a 100-mm visual analog scale (VAS). RESULTS: A specific diagnosis was made in 50 of 55 patients (91%) in the EBUS-TBNA group and in 48 of 55 patients (87%) in the EUS-FNA group (P = .76). Compared with EBUS-TBNA, EUS-FNA was associated with a shorter duration of procedure (median, 15.3 min vs 11.3 min; P < .001), lower doses of IV midazolam (mean, 4.4 mg vs 4 mg; P = .02) and intraairway lidocaine (mean, 303 mg vs 189 mg; P < .001), less frequent oxygen desaturations (23 of 55 vs two of 55, P < .001), and higher operator satisfaction (P < .001). There was no significant difference in patient tolerance according to the patients' VAS. Lymph node infection occurred in one patient in the EBUS-TBNA group and in two patients in the EUS-FNA group. CONCLUSIONS: Both EBUS-TBNA and EUS-FNA provide high accuracy with good tolerance, although the occurrence of infectious complications should be monitored carefully. EUS-FNA has the advantage of comparable tolerance with fewer doses of anesthetics and sedatives, a shorter procedure time, and fewer oxygen desaturations during the procedure. TRIAL REGISTRY: UMIN Clinical Trials Registry; No.: UMIN000005757; URL: http://www.umin.ac.jp/ctr/.

Glycerophosphate/Acylglycerophosphate acyltransferases.

Acyl-CoA:glycerol-3-phosphate acyltransferase (GPAT) and acyl-CoA: 1-acyl-glycerol-3-phosphate acyltransferase (AGPAT) are involved in the de novo synthesis of triacylglycerol (TAG) and glycerophospholipids. Many enzymes belonging to the GPAT/AGPAT family have recently been identified and their physiological or pathophysiological roles have been proposed. The roles of GPAT/AGPAT in the synthesis of TAG and obesity-related diseases were revealed through the identification of causative genes of these diseases or analyses of genetically manipulated animals. Recent studies have suggested that some isoforms of GPAT/AGPAT family enzymes are involved in the fatty acid remodeling of phospholipids. The enzymology of GPAT/AGPAT and their physiological/ pathological roles in the metabolism of glycerolipids have been described and discussed in this review.

Sphingomyelin synthase 2, but not sphingomyelin synthase 1, is involved in HIV-1 envelope-mediated membrane fusion.

Membrane fusion between the viral envelope and plasma membranes of target cells has previously been correlated with HIV-1 infection. Lipids in the plasma membrane, including sphingomyelin, may be crucially involved in HIV-1 infection; however, the role of lipid-metabolic enzymes in membrane fusion remains unclear. In this study, we examined the roles of sphingomyelin synthase (SMS) in HIV-1 Env-mediated membrane fusion using a cell-cell fusion assay with HIV-1 mimetics and their target cells. We employed reconstituted cells as target cells that stably express Sms1 or Sms2 in Sms-deficient cells. Fusion susceptibility was ∼5-fold higher in Sms2-expressing cells (not in Sms1-expressing cells) than in Sms-deficient cells. The enhancement of fusion susceptibility observed in Sms2-expressing cells was reversed and reduced by Sms2 knockdown. We also found that catalytically nonactive Sms2 promoted membrane fusion susceptibility. Moreover, SMS2 co-localized and was constitutively associated with the HIV receptor·co-receptor complex in the plasma membrane. In addition, HIV-1 Env treatment resulted in a transient increase in nonreceptor tyrosine kinase (Pyk2) phosphorylation in Sms2-expressing and catalytically nonactive Sms2-expressing cells. We observed that F-actin polymerization in the region of membrane fusion was more prominent in Sms2-expressing cells than Sms-deficient cells. Taken together, our research provides insight into a novel function of SMS2 which is the regulation of HIV-1 Env-mediated membrane fusion via actin rearrangement.

Endobronchial ultrasound-guided transbronchial needle aspiration in the diagnosis of small cell lung cancer.

BACKGROUND: Massive lymphadenopathy and direct mediastinal invasion are well-recognized phenomena in patients with small cell lung cancer (SCLC). The aim of this study was to assess the utility of endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) in the diagnosis of SCLC. METHODS: We retrospectively reviewed the records of 780 patients who underwent EBUS-TBNA at our institution from March 2004 to June 2012. Of these, 101 had a final diagnosis of SCLC. Excluding 3 patients with known SCLC who underwent EBUS-TBNA for staging purposes and including 2 patients who underwent EBUS-TBNA twice for the diagnosis of recurrence after achieving complete response by chemoradiation therapy during the study period, a total of 100 EBUS-TBNA procedures in 98 patients were analyzed. RESULTS: Other diagnostic tests prior to the initial EBUS-TBNA had failed to yield a diagnosis in 41 patients. The overall diagnostic yield of EBUS-TBNA for SCLC was 97% (97 of 100). Rapid on-site cytologic evaluation (ROSE) was performed at the operator's discretion in 77 procedures. ROSE did not have any impact on diagnostic yield (99% with ROSE vs. 90% without ROSE, p=0.1), but the use of ROSE was associated with fewer lesions (mean 1.1 with ROSE vs. 1.6 without ROSE, p<0.01) or aspirates (mean 2.3 with ROSE vs. 4.0 without ROSE, p<0.01). CONCLUSIONS: EBUS-TBNA provided a high diagnostic yield in SCLC with or without ROSE. EBUS-TBNA can be recommended for patients suspected to have SCLC, even if other diagnostic tests have failed.