Periostin is a mesenchymal cell marker predominantly expressed in collagen-rich fibrous connective tissues, including heart valves, tendons, perichondrium, periosteum, and periodontal ligament (PDL). ...Knockdown of periostin expression in mice results in early-onset periodontitis and failure of cardiac healing after acute myocardial infarction, suggesting that periostin is essential for connective tissue homeostasis and regeneration. However, its role(s) in periodontal tissues has not yet been fully defined. In this study, we describe a novel human isoform of periostin (PDL-POSTN). Isoform-specific analysis by reverse-transcription polymerase chain-reaction (RT-PCR) revealed that PDL-POSTN was predominantly expressed in the PDL, with much lower expression in other tissues and organs. A PDL cell line transfected with PDL-POSTN showed enhanced alkaline phosphatase (ALPase) activity and calcified nodule formation, compared with cells transfected with the full-length periostin isoform. A neutralizing antibody against integrin-αv inhibited both ALPase activity and calcified nodule formation in cells transfected with PDL-POSTN. Furthermore, co-immunoprecipitation assays revealed that PDL-POSTN bound to integrin αvβ3 more strongly than the common isoform of periostin, resulting in strong activation of the integrin αvβ3-focal adhesion kinase (FAK) signaling pathway. These results suggest that PDL-POSTN positively regulates cytodifferentiation and mineralization in PDL cells through integrin αvβ3.
The telomerase complex is responsible for telomere maintenance and represents a promising neoplasia therapeutic target. Recently, we have demonstrated that treatment with a G-quadruplex-interactive ...agent, telomestatin reproducibly inhibited telomerase activity in the BCR-ABL-positive leukemic cell lines. In the present study, we investigated the mechanisms of apoptosis induced by telomerase inhibition in acute leukemia. We have found the activation of caspase-3 and poly-(ADP-ribose) polymerase in telomestatin-treated U937 cells (PD20) and dominant-negative DN-hTERT-expressing U937 cells (PD25). Activation of p38 mitogen-activated protein (MAP) kinase and MKK3/6 was also found in telomestatin-treated U937 cells (PD20) and dominant-negative DN-hTERT-expressing U937 cells (PD25); however, activation of JNK and ASK1 was not detected in these cells. To examine the effect of p38 MAP kinase inhibition on growth properties and apoptosis in telomerase-inhibited cells, we cultured DN-hTERT-expressing U937 cells with or without SB203580. Dominant-negative-hTERT-expressing U937 cells stopped proliferation on PD25; however, a significant increase in growth rate was observed in the presence of SB203580. Treatment of SB203580 also reduced the induction of apoptosis in DN-hTERT-expressing U937 cells (PD25). These results suggest that p38 MAP kinase has a critical role for the induction of apoptosis in telomerase-inhibited leukemia cells. Further, we evaluated the effect of telomestatin on the growth of U937 cells in xenograft mouse model. Systemic intraperitoneal administration of telomestatin in U937 xenografts decreased tumor telomerase levels and reduced tumor volumes. Tumor tissue from telomestatin-treated animals exhibited marked apoptosis. None of the mice treated with telomestatin displayed any signs of toxicity. Taken together, these results lay the foundations for a program of drug development to achieve the dual aims of efficacy and selectivity in vivo.
PLAP-1/asporin is an extracellular matrix protein that is predominantly expressed in the human periodontal ligament (PDL) and has an aspartic acid (D) repeat polymorphism in its N-terminal region. In ...this study, we hypothesized that the D repeat polymorphism of PLAP-1/asporin may affect the physiological functions of periodontal ligaments. We established periodontal ligament cell lines transfected with the D13- or D14-PLAP-1 gene. Alkaline phosphatase staining and alizarin red staining revealed that the cytodifferentiation of the D14-PLAP-1-expressing PDL cells was more repressed compared with that of the D13-PLAP-1-expressing cells. Furthermore, the D14-PLAP-1-expressing cells inhibited BMP-2-induced cytodifferentiation more strongly than did the D13-PLAP-1-expressing cells. Western blotting analysis and luciferase assay revealed that D14-PLAP-1 suppressed BMP-2 signal transduction more efficiently than did D13-PLAP-1, and co-immunoprecipitation demonstrated the stronger affinity of the D14-PLAP-1 protein to BMP-2 compared with the D13-PLAP-1 protein. Analysis of these data suggests that the D repeat polymorphism of PLAP-1/asporin has a significant influence on the functions of PDL cells.
Background
Viral infections and their occult reactivation occasionally cause not only organ damage, but also exacerbation of acute graft‐versus‐host disease (aGVHD), which may increase ...transplantation‐related mortality synergistically. To determine correlations between viral reactivation and transplantation‐related complications, we performed various viral screening tests on the 30th day after allogeneic hematopoietic stem cell transplantation (HSCT), and assessed the clinical implications.
Patients and methods
Between August 2007 and January 2013, 49 patients (37 men, 12 women) underwent HSCT in our hospital. The stem cell sources were bone marrow (n = 21), peripheral blood (n = 13), and cord blood (n = 15). The presence of cytomegalovirus (CMV), Epstein–Barr virus (EBV), herpesvirus (HHV) 6, and HHV7 in plasma samples prospectively collected from HSCT recipients on day 30 after HSCT was assayed by quantitative polymerase chain reaction, and the correlations with transplantation‐related complications were evaluated.
Results
The positivities of CMV, EBV, HHV6, and HHV7 were 44.9%, 22.4%, 53.1%, and 18.3%, respectively. We analyzed transplantation‐related complications, and a significant correlation was found only between HHV6 and grade 2–4 aGVHD from day 30 to day 100 (P < 0.001). Using a receiver operating characteristic curve, the area under the curve was calculated as 0.86 (95% confidence interval CI, 0.74–0.98) between the viral load (VL) of HHV6 and grade 2–4 aGVHD. The sensitivity and specificity were 79% and 93%, respectively, when a cutoff value of 87 copies/mL was used. In multivariate analysis using the Fine and Gray proportional hazards model, the clinically determined high‐risk patients (P = 0.004; hazard ratio HR, 3.69; 95% CI, 1.52–9.00) and the positivity of HHV6 (P < 0.001; HR, 9.957; 95% CI, 2.68–37.06) were extracted as independent risk factors for the cumulative incidence of grade 2–4 aGVHD on or after post‐HSCT day 30. The only risk factor extracted for the elevation of HHV6 VL >87 copies/mL was cord blood transplantation (P = 0.0032; odds ratio, 7.10; 95% CI, 1.98–30.00).
Conclusion
All of the risk factors previously reported to predict severe aGVHD were obtained only during, but not after, HSCT. Our study suggests that the reactivation of HHV6 (≥87 copies/mL) at 30 days after HSCT is a possible predictive marker for grade 2–4 aGVHD on or after post‐HSCT day 30.
To overcome imatinib resistance, more potent ABL tyrosine kinase inhibitors (TKIs), such as nilotinib and dasatinib have been developed, with demonstrable preclinical activity against most ...imatinib-resistant BCR-ABL kinase domain mutations, with the exception of T315I. However, imatinib-resistant patients already harboring mutations have a higher likelihood of developing further mutations under the selective pressure of potent ABL TKIs. NVP-AUY922 (Novartis) is a novel 4,5-diaryloxazole adenosine triphosphate-binding site heat shock protein 90 (HSP90) inhibitor, which has been shown to inhibit the chaperone function of HSP90 and deplete the levels of HSP90 client protein including BCR-ABL. In this study, we investigated the combined effects of AUY922 and nilotinib on random mutagenesis for BCR-ABL mutation (Blood, 109; 5011, 2007). Compared with single agents, combination with AUY922 and nilotinib was more effective at reducing the outgrowth of resistant cell clones. No outgrowth was observed in the presence of 2 μM of nilotinib and 20 nM of AUY922. The observed data from the isobologram indicated the synergistic effect of simultaneous exposure to AUY922 and nilotinib even in BaF3 cells expressing BCR-ABL mutants including T315I. In vivo studies also demonstrated that the combination of AUY922 and nilotinib prolonged the survival of mice transplanted with mixture of BaF3 cells expressing wild-type BCR-ABL and mutant forms. Taken together, this study shows that the combination of AUY922 and nilotinib exhibits a desirable therapeutic index that can reduce the in vivo growth of mutant forms of BCR-ABL-expressing cells.
A beam halo collimator was installed at the Accelerator Test Facility ATF2 in the spring of 2016. The main objective of the collimator is the reduction of background photons that limit the ...performance of key diagnostic devices around the Interaction Point, especially the Shintake Monitor, used for measuring the nanometer level vertical beam sizes, and the vertical and horizontal Diamond Sensors, used for transverse beam halo measurements. In this paper we present the simulations performed to optimize the efficiency of the collimator as well as the wakefield study performed in order to optimize the geometry and material of the collimator jaws. Finally, measurements of the cleaning efficiency and of the collimator induced wakefields impact on the orbit, performed during the Spring and Fall 2016 runs, are presented and compared with simulations.
The high luminosity requirement for a future linear collider sets a demanding limit on the beam quality at the Interaction Point (IP). One potential source of luminosity loss is the motion of the ...ground itself. The resulting misalignments of the quadrupole magnets cause distortions to the beam orbit and hence an increase in the beam emittance. This paper describes a technique for compensating this orbit distortion by using seismometers to monitor the misalignment of the quadrupole magnets in real-time.
The first demonstration of the technique was achieved at the Accelerator Test Facility (ATF) at KEK in Japan. The feed-forward system consisted of a seismometer-based quadrupole motion monitoring system, an FPGA-based feed-forward processor and a stripline kicker plus associated electronics. Through the application of a kick calculated from the position of a single quadruple, the system was able to remove about 80% of the component of the beam jitter that was correlated to the motion of the quadrupole. As a significant fraction of the orbit jitter in the ATF final focus is due to sources other than quadrupole misalignment, this amounted to an approximately 15% reduction in the absolute beam jitter.
A beam position monitor (BPM) with the nanometer-scale position resolution and the decay time of approximately 20 ns is developed as an interaction point BPM, to verify the nanometer stabilization of ...the International Linear Collider beam trains at the Accelerator Test Facility (ATF), High Energy Accelerator Research Organization (KEK). The developed low-Q cavity BPM consists of a one-cell sensor cavity and a one-cell reference cavity. An electronic system is developed, based on the beam test results, to process the signals from the BPM. The beam position resolution of the low-Q cavity BPM with the electronics system is measured at the ATF2 beam line of KEK, and the results of the beam tests conducted on the developed low-Q cavity-type BPM are described.
In this paper, the linear and second order optics corrections for the KEK Accelerator Test Facility (ATF2) final focus beam line are described. The beam optics of the ATF2 beam line is designed based ...on a local chromaticity correction scheme similar to the ILC final focus system. Beam measurements in 2012 revealed skew sextupole field errors that were much larger than expected from magnetic field measurements. The skew sextupole field error was a critical limitation of the beam size at the ATF2 virtual interaction point (IP). Therefore, four skew sextupole magnets were installed to correct the field error in August 2012. By using the four skew sextupole magnets, the predicted tolerances of the skew sextupole field errors of the ATF2 magnets were increased. Furthermore, analyzing field maps of the sextupole magnets identified the source of the skew sextupole field error. After the field error source was removed, the IP vertical beam size could more easily be focused to less than 65 nm.
Allogeneic stem cell transplantation (allo-SCT) is a potentially curative therapy for chronic myeloid leukemia and Philadelphia chromosome-positive (Ph(+)) acute lymphoblastic leukemia, and the ...graft-vs-leukemia (GVL) effect can eradicate residual leukemia after allo-SCT. Ph(+) leukemia cells frequently express death-inducing receptors (DR4 and DR5) for tumor necrosis factor-related apoptosis-inducing ligand (TRAIL), which is one of the cytotoxic ligands expressed on cytotoxic T cells and natural killer cells mediating the GVL effect. Here we demonstrate that imatinib specifically downregulated DR4 and DR5 expression in cell lines and clinical samples of Ph(+) leukemia. Second-generation tyrosine kinase inhibitors (dasatinib and nilotinib) and short hairpin RNA against bcr-abl also downregulated DR4 and DR5 expression in Ph(+) leukemia cells, and transfection of bcr-abl into a Ph(-) leukemia cell line induced DR4 and DR5 expression, which was abrogated by imatinib treatment. Accordingly, Ph(+) leukemia cells that had been pretreated with imatinib showed resistance to the pro-apoptotic activity of recombinant human soluble TRAIL. These observations demonstrate that BCR-ABL is critically involved in the leukemia-specific expression of DR4 and DR5 and in the susceptibility of Ph(+) leukemia to TRAIL-mediated anti-leukemic activity, providing new insight into the mechanisms of the tumor-specific cytotoxic activities of TRAIL.
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