A combination of biochemical and proteomic analyses reveals Bx-LEC-1 as an antigenic target for the monoclonal antibody 3-2A7-2H5-D9-F10 specific to the pine wood nematode.

Pine wilt disease (PWD) is one of the most devastating forest diseases in Asia and Europe. The pine wood nematode, Bursaphelenchus xylophilus, has been identified as the pathogen underlying PWD, although the pathology is not completely understood. At present, diagnosis and confirmation of PWD are time consuming tasks that require nematode extraction and microscopic examination. To develop a more efficient detection method for B. xylophilus, we first generated monoclonal antibodies (MAbs) specific to B. xylophilus. Among 2304 hybridoma fusions screened, a hybridoma clone named 3-2A7-2H5 recognized a single protein from B. xylophilus specifically, but not those from other closely related nematodes. We finally selected the MAb clone 3-2A7-2H5-D9-F10 (D9-F10) for further studies. To identify the antigenic target of MAb-D9-F10, we analyzed proteins in spots, fractions, or bands isolated from SDS-PAGE, two-dimensional electrophoresis, anion exchange chromatography, and immunoprecipitation via nano liquid chromatography electrospray ionization quadrupole ion trap mass spectrometry (nano-LC-ESI-Q-IT-MS). Peptides of galactose-binding lectin-1 of B. xylophilus (Bx-LEC-1) were commonly detected in several proteomic analyses, demonstrating that this LEC-1 is the antigenic target of MAb-D9-F10. The localization of MAb-D9-F10 immunoreactivities at the area of the median bulb and esophageal glands suggested that the Bx-LEC-1 may be involved in food perception and digestion. The Bx-LEC-1 has two nonidentical galactose-binding lectin domains important for carbohydrate binding. The affinity of the Bx-LEC-1 to D-(+)-raffinose and N-acetyllactosamine were much higher than that to L-(+)-rhamnose. Based on this combination of evidences, MAb-D9-F10 is the first identified molecular biomarker specific to the Bx-LEC-1.

Combination treatment with VPA and MSCs­TRAIL could increase anti­tumor effects against intracranial glioma.

Human bone marrow­derived mesenchymal stem cells secreting tumor necrosis factor­related apoptosis­inducing ligand (MSCs­TRAIL) have demonstrated effective anti­tumor activity against various tumors including lung, pancreatic and prostate tumors, although several tumor types are not responsive. In such case, other reagents may decrease tumor growth via TRAIL­mediated cell death. The present study aimed to examine the effectiveness of valproic acid (VPA) in enhancing the efficacy of TRAIL, which was delivered using MSCs. Moreover, the present study examined the induced tumor tropism of MSCs via cell viability and migration assays. Combination treatment with VPA and MSCs­TRAIL enhanced the glioma therapeutic effect by increasing death receptor 5 and caspase activation. Migration assays identified increased MSC migration in VPA and MSCs­TRAIL­treated glioma cells and in the tumor site in glioma­bearing mice compared with VPA or MSC­TRAIL treatment alone. In vivo experiments demonstrated that MSC­based TRAIL gene delivery to VPA­treated tumors had greater therapeutic efficacy compared with treatment with each agent alone. These findings suggested that VPA treatment increased the therapeutic efficacy of MSC­TRAIL via TRAIL­induced apoptosis and enhanced tropism of MSCs, which may offer a useful strategy for tumor gene therapy.

Evaluation of Combination Treatment Effect With TRAIL-secreting Mesenchymal Stem Cells and Compound C Against Glioblastoma.

BACKGROUND/AIM: Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) triggers apoptosis of cancer cells and, when used in combination with other anticancer drugs, is regarded as an effective strategy for anticancer treatment. In this study, we investigated the efficacy of combination treatment with TRAIL-secreting human mesenchymal stem cells (MSC-TRAIL) and compound C, an AMP-activated protein kinase (AMPK inhibitor), on glioblastoma. MATERIALS AND METHODS: The anticancer effect using MSC-TRAIL and compound C on glioma was evaluated in vitro and on in vivo models. RESULTS: Combination treatment of MSC-TRAIL and compound C increased apoptosis by enhancing expression of B-cell lymphoma 2 (BCL2)-associated X protein (BAX) and reducing that of anti-apoptotic proteins cellular FLICE-inhibitory protein (FLIP), X-linked inhibitor of apoptosis (XIAP), and BCL2 in glioma. In addition, MSC-TRAIL and compound C combination increased caspase-3 cleavage and apoptotic cells in a mouse glioma model compared with the group treated with the agents alone. CONCLUSION: Our results suggest that MSC-TRAIL and compound C are a novel combination for treatment of glioma.

Migration and Attacking Ability of Bursaphelenchus mucronatus in Pinus thunbergii Stem Cuttings.

To understand how Bursaphelenchus xylophilus kills pine trees, the differences between the effects of B. xylophilus and B. mucronatus on pine trees are usually compared. In this study, the migration and attacking ability of a non-pathogenic B. mucronatus in Pinus thunbergii were investigated. The distribution of B. mucronatus and the number of dead epithelial cells resulting from inoculation were compared with those of the pathogenic B. xylophilus. Although B. mucronatus is non-pathogenic in pines, its distribution pattern in P. thunbergii was the same as that of B. xylophilus. We therefore concluded that the non-pathogenicity of B. mucronatus could not be attributed to its migration ability. The sparse and sporadic attacking pattern of B. mucronatus was also the same as that of B. xylophilus. However, the number and area of the dead epithelial cells in pine cuttings inoculated with B. mucronatus were smaller than in those cuttings inoculated with B. xylophilus, meaning that the attacking ability of B. mucronatus is weaker than that of B. xylophilus. Therefore, we concluded that the weaker attacking ability of B. mucronatus might be the factor responsible for the non-pathogenicity.

Growth and density-dependent regulation of NO synthase by the actin cytoskeleton in pulmonary artery endothelial cells.

We previously reported association of eNOS with actin increases eNOS activity. In the present study, regulation of activity of eNOS by actin cytoskeleton during endothelial growth was studied. We found eNOS activity in PAEC increased when cells grew from preconfluence to confluence. eNOS activity was much greater in PAEC in higher density than those in lower density, suggesting increase in eNOS activity during cell growth is caused by increase in cell density. Although eNOS protein contents were also increased when endothelial cells grew from preconfluence to confluence, magnitude of increase in eNOS activity was much higher than increase in eNOS protein content, suggesting posttranslational mechanisms played an important role in regulation of eNOS activity during endothelial growth. Confocal fluorescence microscopy revealed eNOS was colocalized with G-actin in preconfluent cells in perinuclear region, with both G-actin in perinuclear area and cortical F-actin in plasma membrane in confluent cells. There was more beta-actin coimmunoprecipitated with eNOS in Triton X-100-soluble fraction in confluent cells in later growth phase and in high density. Decrease in eNOS association with beta-actin by silencing beta-actin expression using beta-actin siRNA causes inhibition of eNOS activity, NO production, and endothelial monolayer wound repair in PAEC. Moreover, PAEC incubation with cytochalasin D and jasplakinolide resulted in increases in eNOS/actin association and in eNOS activity without changes in eNOS protein content. Yeast two-hybrid experiments suggested strong association between eNOS oxygenase domain and beta-actin. These results indicate increase in eNOS association with actin is responsible for greater eNOS activity in confluent PAEC.