Engineering CD3/CD137 Dual Specificity into a DLL3-Targeted T-Cell Engager Enhances T-Cell Infiltration and Efficacy against Small-Cell Lung Cancer

Small-cell lung cancer (SCLC) is an aggressive cancer for which immune checkpoint inhibitors (ICI) have had only limited success. Bispecific T-cell engagers are promising therapeutic alternatives for ICI-resistant tumors, but not all patients with SCLC are responsive. Herein, to integrate CD137 costimulatory function into a T-cell engager format and thereby augment therapeutic efficacy, we generated a CD3/CD137 dual-specific Fab and engineered a DLL3-targeted trispecific antibody (DLL3 trispecific). The CD3/CD137 dual-specific Fab was generated to competitively bind to CD3 and CD137 to prevent DLL3-independent cross-linking of CD3 and CD137, which could lead to systemic T-cell activation. We demonstrated that DLL3 trispecific induced better tumor growth control and a marked increase in the number of intratumoral T cells compared with a conventional DLL3-targeted bispecific T-cell engager. These findings suggest that DLL3 trispecific can exert potent efficacy by inducing concurrent CD137 costimulation and provide a promising therapeutic option for SCLC.

Effect of acid suppressant medications on the laxative action of magnesium preparations in patients with opioid-induced constipation: A pharmacovigilance analysis of the FDA Adverse Event Reporting System

Objective: Magnesium oxide is widely used for treating opioid-induced constipation, a serious analgesic-associated problem. Opioid analgesic users are often prescribed non-steroidal anti-inflammatory drugs, which are sometimes combined with acid suppressants to prevent gastrointestinal adverse events. Magnesium preparations combined with acid suppressants may diminish magnesium preparations' laxative effect. This study was aimed at evaluating the effect of magnesium preparations combined with acid suppressants on the incidence of opioid-induced constipation by using the Food and Drug Administration Adverse Event Reporting System. Methods: Adverse events were defined per the Medical Dictionary for Regulatory Activities; the term 'constipation (preferred term code: 10010774)' was used for analysis. After adjusting for patient background factors using propensity score matching, acid suppressants' effect on constipation incidence was evaluated in opioid users prescribed magnesium preparations alone as laxatives by using a test for independence. Key Findings: The Food and Drug Administration Adverse Event Reporting System contains 14,475,614 reports for January 2004 to December 2021. Significantly increased constipation incidence was related to magnesium preparations combined with acid suppressants, especially proton pump inhibitors (P < 0.0001, McNemar's test). Conclusion: Magnesium preparations combined with acid suppressants may diminish magnesium preparations' laxative effect; healthcare professionals should pay attention to this issue.

New evidence for the Ontong Java Nui hypothesis

The formation of the Ontong Java Nui super oceanic plateau (OJN), which is based on the model that the submarine Ontong Java Plateau (OJP), Manihiki Plateau (MP), and Hikurangi Plateau (HP) were once its contiguous fragments, could have been the largest globally consequential volcanic event in Earth's history. This OJN hypothesis has been debated given the paucity of evidence, for example, the differences in crustal thickness, the compositional gap between MP and OJP basalts and the apparent older age of both plateaus relative to HP remain unresolved. Here we investigate the geochemical and ⁴⁰Ar-³⁹Ar ages of dredged rocks recovered from the OJP's eastern margin. Volcanic rocks having compositions that match the low-Ti MP basalts are reported for the first time on the OJP and new ~ 96-116 Ma and 67-68 Ma ⁴⁰Ar-³⁹Ar age data bridge the temporal gap between OJP and HP. These results provide new evidence for the Ontong Java Nui hypothesis and a framework for an integrated tectonomagmatic evolution of the OJP, MP, and HP. The isotopic data imply four mantle components in the source of OJN that are also expressed in present-day Pacific hotspots sources, indicating origin from (and longevity of) the Pacific Large Low Shear-wave Velocity Province.

Abstract 1872: A DLL3/CD3/CD137 trispecific T cell engager shows potent antitumor activity in small cell lung cancer models

Background: Despite the approval of immune checkpoint inhibitors (ICIs), prognosis of small cell lung cancer (SCLC) remains poor. DLL3 is upregulated in SCLC whereas expression in normal tissues is minimal, representing the favorable profile as a therapeutic target. T cell engager (TCE) is a potent immunotherapy that redirects T cells to tumors expressing a specific antigen. Unlike ICIs, TCEs do not require the recognition of tumor antigens by T cells and thus could be an alternative approach to target tumors where the benefit of ICIs is limited such as SCLC. CD137 (4-1BB) is a costimulatory molecule that promotes T cell activation, proliferation, and survival. Since CD137 agonists synergize with CD3-mediated T cell activation, inducing concurrent CD137 costimulation is a promising strategy to unleash the potential of TCEs. We therefore developed a DLL3/CD3/CD137 trispecific T cell engager composed of two CD3/CD137 dual specific Fabs and one extra DLL3 Fab (DLL3 trispecific, RG6524).

Results: We initially investigated the CD3 and CD137 signal transduction in Jurkat cells harboring NFAT or NF-κB reporter cocultured with DLL3 positive cells. DLL3 trispecific showed dose-dependent increase in NFAT and NF-κB activity, indicating that target engagement successfully activated CD3 and CD137 signaling. In the in vitro assay using human PBMC, DLL3 trispecific induced cytotoxicity against SCLC cell lines with EC50s in the two-digit pM range.

In vivo efficacy was evaluated in SCLC xenograft models established by engrafting SCLC cell lines into immune humanized NOG mice. DLL3 trispecific showed greater tumor growth inhibition compared to a traditional bispecific T cell engager. Furthermore, flow cytometry-based immunophenotyping revealed that DLL3 trispecific increased T cell number in tumors and improved IFN-γ production from CD8 T cells. We also explored the combination with platinum-based drugs, which are widely used for SCLC, and showed that DLL3 trispecific enhanced the efficacy of platinum-based drugs. These data demonstrated that DLL3 trispecific has the potent in vivo efficacy and the potential for clinical use.

We next evaluated whether cytokine release syndrome (CRS) mitigating approaches affect antitumor efficacy. Although prophylactic use of a steroid significantly reduced cytokine production, tumor growth inhibition by DLL3 trispecific remained unchanged. Likewise, tocilizumab treatment did not reduce the efficacy, suggesting that CRS mitigation did not abrogate the therapeutic benefit.

We finally assessed the tolerability in non-human primates. DLL3 trispecific did not reach the maximum tolerated dose and was well tolerated up to 16 mg/kg Q2D, the highest dose tested.

Conclusion: Our data showed that DLL3 trispecific has potent activity and is well suited for clinical application in SCLC. These findings provide a rationale for the clinical testing of DLL3 trispecific.

Citation Format: Hirofumi Mikami, Shu Feng, Sotaro Naoi, Yumiko Azuma, Yoko Kayukawa, Toshiaki Tsunenari, Kentaro Asanuma, Ryutaro Iwabuchi, Hiroaki Nagano, Junko Shinozuka, Masaki Yamazaki, Haruka Kuroi, Siok Wan Gan, Priyanka Chichili, Shun Shimizu, Yutaka Matsuda, Shinya Ishii, Shogo Kamikawaji, Yasuko Kinoshita, Yuichiro Shimizu, Akihisa Sakamoto, Masaru Muraoka, Noriyuki Takahashi, Tatsuya Kawa, Hirotake Shiraiwa, Kenji Kashima, Futa Mimoto, Mika Kamata-Sakurai, Takehisa Kitazawa, Tomoyuki Igawa. A DLL3/CD3/CD137 trispecific T cell engager shows potent antitumor activity in small cell lung cancer models [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 1872.

Longitudinal changes in life-space mobility and the factors influencing it among chronic community-dwelling post-stroke patients

PURPOSE

To identify longitudinal changes in life-space mobility and the factors influencing it among chronic, stable post-stroke patients.

MATERIALS AND METHODS

This prospective study included Japanese post-stroke patients who received day-care rehabilitation services and could undergo three life-space mobility assessments (at baseline, 12, and 24 months) for over 2 years, using the Life-Space Assessment (LSA) tool. Physical function, cognitive function, and activities of daily living were assessed by self-selected comfortable gait speed, Mini-Mental State Examination (MMSE), and Functional Independence Measure Motor subscale (FIM motor) scores, respectively, in addition to age, sex, time from onset, stroke type, and comorbidities. A multivariable linear mixed-effects model was used to examine the longitudinal changes in LSA scores and associated factors.

RESULTS

A total of 89 participants were enrolled. At baseline, the median age was 74 years, 33% were women, and median time from onset was 75 months. The LSA scores significantly declined over the two-year period. In the multivariate linear mixed-effects model adjusted for clinical characteristics, comfortable gait speed and age were significantly associated with changes in the LSA score, independent of FIM motor scores and MMSE scores.

CONCLUSIONS

Life-space mobility may persistently decline, and gait function may be a determinant influencing these changes in community-dwelling chronic post-stroke patients.Implications for RehabilitationLimited life-space mobility leads to less frequent participation in social activities and an increased risk of adverse health outcomes such as hospitalization.Changes in life-space mobility should be considered in the rehabilitation care plan for chronic post-stroke patients.Life-space mobility may decline persistently in stable post-stroke patients, even if they have periodically received day-care rehabilitation services.Since gait speed is a predominant factor affecting life-space mobility, regular assessment of gait function and appropriate strategies are needed to prevent deterioration of gait speed in chronic post-stroke patients.

Longitudinal Flow Decorrelations in Xe+Xe Collisions at sqrt[s_{NN}]=5.44 TeV with the ATLAS Detector

The first measurement of longitudinal decorrelations of harmonic flow amplitudes v_{n} for n=2-4 in Xe+Xe collisions at sqrt[s_{NN}]=5.44  TeV is obtained using 3  μb^{-1} of data with the ATLAS detector at the LHC. The decorrelation signal for v_{3} and v_{4} is found to be nearly independent of collision centrality and transverse momentum (p_{T}) requirements on final-state particles, but for v_{2} a strong centrality and p_{T} dependence is seen. When compared with the results from Pb+Pb collisions at sqrt[s_{NN}]=5.02  TeV, the longitudinal decorrelation signal in midcentral Xe+Xe collisions is found to be larger for v_{2}, but smaller for v_{3}. Current hydrodynamic models reproduce the ratios of the v_{n} measured in Xe+Xe collisions to those in Pb+Pb collisions but fail to describe the magnitudes and trends of the ratios of longitudinal flow decorrelations between Xe+Xe and Pb+Pb. The results on the system-size dependence provide new insights and an important lever arm to separate effects of the longitudinal structure of the initial state from other early and late time effects in heavy-ion collisions.

Exploitation of Elevated Extracellular ATP to Specifically Direct Antibody to Tumor Microenvironment

The extracellular adenosine triphosphate (ATP) concentration is highly elevated in the tumor microenvironment (TME) and remains tightly regulated in normal tissues. Using phage display technology, we establish a method to identify an antibody that can bind to an antigen only in the presence of ATP. Crystallography analysis reveals that ATP bound in between the antibody-antigen interface serves as a switch for antigen binding. In a transgenic mouse model overexpressing the antigen systemically, the ATP switch antibody binds to the antigen in tumors with minimal binding in normal tissues and plasma and inhibits tumor growth. Thus, we demonstrate that elevated extracellular ATP concentration can be exploited to specifically target the TME, giving therapeutic antibodies the ability to overcome on-target off-tumor toxicity.

Search for Higgs Boson Decays into a Z Boson and a Light Hadronically Decaying Resonance Using 13 TeV pp Collision Data from the ATLAS Detector

A search for Higgs boson decays into a Z boson and a light resonance in two-lepton plus jet events is performed, using a pp collision dataset with an integrated luminosity of 139  fb^{-1} collected at sqrt[s]=13  TeV by the ATLAS experiment at the CERN LHC. The resonance considered is a light boson with a mass below 4 GeV from a possible extended scalar sector or a charmonium state. Multivariate discriminants are used for the event selection and for evaluating the mass of the light resonance. No excess of events above the expected background is found. Observed (expected) 95% confidence-level upper limits are set on the Higgs boson production cross section times branching fraction to a Z boson and the signal resonance, with values in the range 17-340 pb (16_{-5}^{+6}-320_{-90}^{+130}  pb) for the different light spin-0 boson mass and branching fraction hypotheses, and with values of 110 and 100 pb (100_{-30}^{+40} and 100_{-30}^{+40}  pb) for the η_{c} and J/ψ hypotheses, respectively.

Protonation-induced self-assembly of bis-phenanthroline macrocycles into nanofibers arrayed with tetrachloroaurate, hexachloroplatinate or phosphomolybdate ions

One-dimensional self-assembly of macrocycles is one of the important strategies for constructing fibrous nanomaterials with anisotropic functions such as one-dimensional transport and accumulation of molecules and ions. Herein we report on the synthesis and properties of self-assembled nanofibers using macrocycles to develop a multipurpose template for one-dimensional array of noble metal ions. The nanofibers were prepared by protonation-induced self-assembly of bis-phenanthroline macrocycles, which have enabled the accumulation of some metal-containing anions, such as tetrachloroaurate, hexachloroplatinate and phosphomolybdate. Microscopic observations have demonstrated that the supramolecular nanofibers were reproducibly formed in a similar way, regardless of the structures and charge numbers of the anions. Moreover, the resulting nanofibers, arrayed with several metal ions, were chemically reduced, producing dispersible gold nanoparticles and mixed-valence nanofibers.

A New Genus and Two New Species of the Subfamily Nesomesochorinae Ashmead (Insecta: Hymenoptera: Ichneumonidae)

Nesomesochorinae is a rather small subfamily of Darwin wasps (Insecta: Hymenoptera: Ichneumonidae), only with three described genera. We recognize a fourth nesomesochorine genus from Perú and describe it as a new genus, Bina Shimizu & Alvarado gen. nov. The new genus is distinguished from previously described genera of Nesomesochorinae by the following combination of character states: mandible parallel-sided proximally and abruptly strongly narrowed ventroapically so that its lower apical tooth is much smaller and sharper than upper tooth; propodeum with lateromedian longitudinal carinae between anterior and posterior transverse carinae developed on more than posterior 0.9 so that the area superomedia is more or less enclosed; thyridium of 2nd metasomal tergite sometimes very large; 1st metasomal tergite stout and arched; body highly shiny. Bina gen. nov. comprises two species also described as new to science: B. huayrurae Shimizu & Alvarado sp. nov. (type species of Bina gen. nov.) and B. nigra Shimizu & Alvarado sp. nov. Identification keys to genera of Nesomesochorinae and to species of Bina gen. nov. are provided.

Effect of therapeutic plasma exchange on phenytoin plasma concentration in patients receiving intravenous fosphenytoin therapy

We report for patients with encephalitis treated with plasma exchange (PE) and fosphenytoin. In patient 1, phenytoin levels decreased on the maintenance dose, and the phenytoin concentration was <10 μg/mL on day 12 of administration. In patient 2, the phenytoin levels was <10 μg/mL on day 4. Increasing the fosphenytoin dose pushed the phenytoin level into therapeutic range. There were no differences between the areas under the concentration-time curve of phenytoin with and without PE. We previously reported a decline in phenytoin levels after prolonged use of fosphenytoin. Therefore, dose adjustment of fosphenytoin in patients undergoing PE may be unnecessary.

Dijet Resonance Search with Weak Supervision Using sqrt[s]=13 TeV pp Collisions in the ATLAS Detector

This Letter describes a search for narrowly resonant new physics using a machine-learning anomaly detection procedure that does not rely on signal simulations for developing the analysis selection. Weakly supervised learning is used to train classifiers directly on data to enhance potential signals. The targeted topology is dijet events and the features used for machine learning are the masses of the two jets. The resulting analysis is essentially a three-dimensional search A→BC, for m_{A}∼O(TeV), m_{B},m_{C}∼O(100  GeV) and B, C are reconstructed as large-radius jets, without paying a penalty associated with a large trials factor in the scan of the masses of the two jets. The full run 2 sqrt[s]=13  TeV pp collision dataset of 139  fb^{-1} recorded by the ATLAS detector at the Large Hadron Collider is used for the search. There is no significant evidence of a localized excess in the dijet invariant mass spectrum between 1.8 and 8.2 TeV. Cross-section limits for narrow-width A, B, and C particles vary with m_{A}, m_{B}, and m_{C}. For example, when m_{A}=3  TeV and m_{B}≳200  GeV, a production cross section between 1 and 5 fb is excluded at 95% confidence level, depending on m_{C}. For certain masses, these limits are up to 10 times more sensitive than those obtained by the inclusive dijet search. These results are complementary to the dedicated searches for the case that B and C are standard model bosons.

Effects of royal jelly on bone metabolism in postmenopausal women: a randomized, controlled study

OBJECTIVES

This study aimed to evaluate the effects of royal jelly (RJ) supplementation on bone metabolism in postmenopausal women.

METHODS

This was a randomized, double-blind, placebo-controlled clinical trial. Seventy-two healthy postmenopausal women aged 45-60 years within 5 years after menopause were randomized into two groups: women in the RJ group (n = 36) received capsules containing dried RJ (equivalent to 3000 mg of fresh RJ); and women in the placebo group (n = 36) received placebo daily for 6 months. Bone mineral density (BMD) of the lumbar spine (L2-L4) and left proximal femur, hip structural analysis (HSA) of the left hip, and bone turnover markers were measured.

RESULTS

Although women in the placebo group experienced a significant loss of BMD and deterioration in HSA parameters of the femur, no significant differences were found in these parameters in women in the RJ group. The levels of total procollagen type 1 N-terminal propeptide (P1NP) and tartrate-resistant acid phosphatase decreased significantly in the placebo group; however, the total P1NP level, a marker of bone formation, was not significantly different in the RJ group at postintervention compared with baseline.

CONCLUSION

RJ consumption may ameliorate decreases in femoral BMD and strength in postmenopausal women.

Antibody to CD137 Activated by Extracellular Adenosine Triphosphate Is Tumor Selective and Broadly Effective In Vivo without Systemic Immune Activation

Agonistic antibodies targeting CD137 have been clinically unsuccessful due to systemic toxicity. Because conferring tumor selectivity through tumor-associated antigen limits its clinical use to cancers that highly express such antigens, we exploited extracellular adenosine triphosphate (exATP), which is a hallmark of the tumor microenvironment and highly elevated in solid tumors, as a broadly tumor-selective switch. We generated a novel anti-CD137 switch antibody, STA551, which exerts agonistic activity only in the presence of exATP. STA551 demonstrated potent and broad antitumor efficacy against all mouse and human tumors tested and a wide therapeutic window without systemic immune activation in mice. STA551 was well tolerated even at 150 mg/kg/week in cynomolgus monkeys. These results provide a strong rationale for the clinical testing of STA551 against a broad variety of cancers regardless of antigen expression, and for the further application of this novel platform to other targets in cancer therapy. SIGNIFICANCE: Reported CD137 agonists suffer from either systemic toxicity or limited efficacy against antigen-specific cancers. STA551, an antibody designed to agonize CD137 only in the presence of extracellular ATP, inhibited tumor growth in a broad variety of cancer models without any systemic toxicity or dependence on antigen expression.See related commentary by Keenan and Fong, p. 20.This article is highlighted in the In This Issue feature, p. 1.

CP Properties of Higgs Boson Interactions with Top Quarks in the tt[over ¯]H and tH Processes Using H→γγ with the ATLAS Detector

A study of the charge conjugation and parity (CP) properties of the interaction between the Higgs boson and top quarks is presented. Higgs bosons are identified via the diphoton decay channel (H→γγ), and their production in association with a top quark pair (tt[over ¯]H) or single top quark (tH) is studied. The analysis uses 139  fb^{-1} of proton-proton collision data recorded at a center-of-mass energy of sqrt[s]=13  TeV with the ATLAS detector at the Large Hadron Collider. Assuming a CP-even coupling, the tt[over ¯]H process is observed with a significance of 5.2 standard deviations. The measured cross section times H→γγ branching ratio is 1.64_{-0.36}^{+0.38}(stat)_{-0.14}^{+0.17}(sys)  fb, and the measured rate for tt[over ¯]H is 1.43_{-0.31}^{+0.33}(stat)_{-0.15}^{+0.21}(sys) times the Standard Model expectation. The tH production process is not observed and an upper limit on its rate of 12 times the Standard Model expectation is set. A CP-mixing angle greater (less) than 43 (-43)° is excluded at 95% confidence level.

Search for Heavy Higgs Bosons Decaying into Two Tau Leptons with the ATLAS Detector Using pp Collisions at sqrt[s]=13 TeV

A search for heavy neutral Higgs bosons is performed using the LHC Run 2 data, corresponding to an integrated luminosity of 139  fb^{-1} of proton-proton collisions at sqrt[s]=13  TeV recorded with the ATLAS detector. The search for heavy resonances is performed over the mass range 0.2-2.5 TeV for the τ^{+}τ^{-} decay with at least one τ-lepton decaying into final states with hadrons. The data are in good agreement with the background prediction of the standard model. In the M_{h}^{125} scenario of the minimal supersymmetric standard model, values of tanβ>8 and tanβ>21 are excluded at the 95% confidence level for neutral Higgs boson masses of 1.0 and 1.5 TeV, respectively, where tanβ is the ratio of the vacuum expectation values of the two Higgs doublets.

Measurement of the Lund Jet Plane Using Charged Particles in 13 TeV Proton-Proton Collisions with the ATLAS Detector

The prevalence of hadronic jets at the LHC requires that a deep understanding of jet formation and structure is achieved in order to reach the highest levels of experimental and theoretical precision. There have been many measurements of jet substructure at the LHC and previous colliders, but the targeted observables mix physical effects from various origins. Based on a recent proposal to factorize physical effects, this Letter presents a double-differential cross-section measurement of the Lund jet plane using 139  fb^{-1} of sqrt[s]=13  TeV proton-proton collision data collected with the ATLAS detector using jets with transverse momentum above 675 GeV. The measurement uses charged particles to achieve a fine angular resolution and is corrected for acceptance and detector effects. Several parton shower Monte Carlo models are compared with the data. No single model is found to be in agreement with the measured data across the entire plane.

Measurement of Azimuthal Anisotropy of Muons from Charm and Bottom Hadrons in pp Collisions at sqrt[s]=13 TeV with the ATLAS Detector

The elliptic flow of muons from the decay of charm and bottom hadrons is measured in pp collisions at sqrt[s]=13  TeV using a data sample with an integrated luminosity of 150  pb^{-1} recorded by the ATLAS detector at the LHC. The muons from heavy-flavor decay are separated from light-hadron decay muons using momentum imbalance between the tracking and muon spectrometers. The heavy-flavor decay muons are further separated into those from charm decay and those from bottom decay using the distance-of-closest-approach to the collision vertex. The measurement is performed for muons in the transverse momentum range 4-7 GeV and pseudorapidity range |η|<2.4. A significant nonzero elliptic anisotropy coefficient v_{2} is observed for muons from charm decays, while the v_{2} value for muons from bottom decays is consistent with zero within uncertainties.

Morphological features of the posterior oblique ligament of the ulnar collateral ligament of the elbow joint

PURPOSE

The purpose of this basic research study was to clarify the morphological characteristics of the posterior oblique fibers (POL) of the ulnar collateral ligament using a large number of specimens.

METHODS

This study examined 50 arms from 25 Japanese cadavers. Type classification was performed by focusing on the positional relationship between POL morphology and the joint capsule. The morphological features measured were fiber bundle length, width, and thickness.

RESULTS

The POL was classified as follows: Type I, the POL's anterior and posterior edges are located on the surface of the joint capsule and can be separated as a single fiber bundle; Type II-a, the POL anterior edge can be separated, but the posterior edge cannot be separated; Type II-b, the POL posterior edge can be separated, but the anterior edge cannot be separated; and Type III, the POL cannot be separated from the joint capsule. Type I was seen in 23 elbows (46%), Type II-a in 6 elbows (12%), Type II-b in 7 elbows (14%), and Type III in 14 elbows (28%).

CONCLUSION

The results of this study suggested that the POL could be classified into an independent type and an unclear type, and the presence of the unclear type was one of the factors that caused morphological variation.

Search for Magnetic Monopoles and Stable High-Electric-Charge Objects in 13 Tev Proton-Proton Collisions with the ATLAS Detector

A search for magnetic monopoles and high-electric-charge objects is presented using 34.4  fb^{-1} of 13 TeV pp collision data collected by the ATLAS detector at the LHC during 2015 and 2016. The considered signature is based upon high ionization in the transition radiation tracker of the inner detector associated with a pencil-shape energy deposit in the electromagnetic calorimeter. The data were collected by a dedicated trigger based on the tracker high-threshold hit capability. The results are interpreted in models of Drell-Yan pair production of stable particles with two spin hypotheses (0 and 1/2) and masses ranging from 200 to 4000 GeV. The search improves by approximately a factor of 5 the constraints on the direct production of magnetic monopoles carrying one or two Dirac magnetic charges and stable objects with electric charge in the range 20≤|z|≤60 and extends the charge range to 60<|z|≤100.

Observation of Electroweak Production of a Same-Sign W Boson Pair in Association with Two Jets in pp Collisions at sqrt[s]=13 TeV with the ATLAS Detector

This Letter presents the observation and measurement of electroweak production of a same-sign W boson pair in association with two jets using 36.1  fb^{-1} of proton-proton collision data recorded at a center-of-mass energy of sqrt[s]=13  TeV by the ATLAS detector at the Large Hadron Collider. The analysis is performed in the detector fiducial phase-space region, defined by the presence of two same-sign leptons, electron or muon, and at least two jets with a large invariant mass and rapidity difference. A total of 122 candidate events are observed for a background expectation of 69±7 events, corresponding to an observed signal significance of 6.5 standard deviations. The measured fiducial signal cross section is σ^{fid}=2.89_{-0.48}^{+0.51}(stat)_{-0.28}^{+0.29}(syst)  fb.

P1618A polymethoxy flavonoid, Nobiletin, Has a therapeutic potency against the development of heart failure through NBP1 activation

Introduction

Maladaptive hypertrophy is being recognized as a critical event during the development of heart failure. The control of cardiac hypertrophy may be one of the therapeutic strategy for heart failure therapy. In our previous study, we screened natural compound library and found that a natural compound, Nobiletin, could inhibit cardiomyocyte hypertrophy in culture. Nobiletin has various useful effects such as anti-cancer, anti-inflammation, and anti-oxidant and may be applicable to pharmacological therapy for heart failure.

Hypothesis

We thought that nobiletin might prevent the development of heart failure in vivo and investigated the target molecule of Nobiletin in the heart.

Methods and results

In primary cardiomyocytes, Nobiletin significantly inhibited phenylephrine (PE)-induced hypertrophic responses such as increases in cell size and hypertrophic gene transcription, such as ANF and BNP. C57BL6 mice were subjected to sham or transarotic constriction (TAC). Oral administrations of Nobiletin (20 mg/kg/day) or vehicle were repeated for 8 weeks. Nobiletin treatment significantly prevented TAC-induced increases in PWT and systolic dysfunction. Nobiletin also suppressed TAC-induced myocardial cell hypertrophy, perivascular fibrosis, and hypertrophic gene transcriptions. To investigate the target molecule of Nobiletin, Nobiletin-binding proteins were purified from rat heart using biotin-conjugated Nobiletin. We identified 162 novel binding protein of Nobiletin by LC/MS-MS. One of them, Nobiletin-binding protein 1 (NBP1) related to cellular metabolic pathway. Pulldown assay demonstrated that biotin-conjugated Nobiletin, but not biotin, directly interacted with recombinant NBP1. In vitro enzyme assay showed that Nobiletin enhanced NBP1 activity. Although NBP1 knockdown could not affect PE-induced hypertrophic response gene transcriptions and cardiomyocyte hypertrophy, NBP1 knockdown failed to exhibit Nobiletin-mediated anti-hypertrophic effects. NBP1-KO mice and WT mice were subjected to sham or TAC and randomly divided into two groups: Nobiletin (20 mg/kg/day) and vehicle. After 8 weeks, Nobiletin significantly improved TAC-induced cardiac hypertrophy and systolic dysfunction in WT mice but not in NBP1-KO mice. Nobiletin also prevented TAC-induced increases in HW/BW rate, myocardial cell hypertrophy, and mRNA levels of ANF and β-MHC in WT mice but not in NBP1-KO mice.

Conclusions

In this study, we demonstrate that Nobiletin inhibits cardiomyocyte hypertrophy and the development of heart failure in vivo. NBP1 activity is required to exhibit therapeutic potency of Nobiletin for heart failure. These finding suggest that a natural compound, nobiletin, might be a candidate for heart failure agent in human.

Acknowledgement/Funding

This work was supported by JSPS KAKENHI Grant.

P1608Inhibition of GATA4 dimerization suppress hypertrophic responses

Introduction

Hypertrophic signals eventually reach the nuclei of cardiomyocytes, change patterns of gene expression, and cause the development of heart failure. During the development of heart failure, intrinsic histone acetyltransferase called p300 induce GATA4 acetylation. Acetylated GATA4 increases its DNA binding, up-regulates cardiac hypertrophic response genes, and lead to heart failure. A zinc finger protein, GATA4 is the transcription factor that expression level is high in heart. It has been reported that GATA1, the same GATA family, regulates transcriptional activity through its homo-dimerization. However, GATA4 homo-dimerization and its relationship to hypertrophic responses are still unknown.

Purpose

To clarify the relationship between GATA4 homo-dimerization and transcriptional activity and investigate whether inhibition of this homo-dimerization become therapeutic target for cardiac hypertrophy.

Methods

GST pull-down and DNA pull-down assay were performed using GST fusion full length and deletion mutants of GATA4 and biotin-conjugated ET-1 promoter probe including a GATA element. Recombinant C-zinc finger domain (256–326), including C-zinc finger motif (256–295) and acetylation site (308–326) was cross-linked using glutaraldehyde and subjected to silver staining. An expression plasmid with three GATA4-acetylation site mutant-conjugated with nuclear localization sequence (3xG4D) was constructed. Immunoprecipitation and western blotting were performed using nuclear extract from HEK293T cells expressing p300, GATA4, and 3xG4D. Luciferase assay was using ANF and ET-1 promoter sequences. Neonatal rat cultured cardiomyocyte expressed 3xG4D and then stimulated with phenylephrine (PE) for 48 hours. Next cardiomyocytes stained with α-actinin antibody and measured the cell surface area.

Results

The acetylation site of GATA4 was required for the dimerization of GATA4. But, C-zinc finger motif (256–295) and the acetylation site were required for the DNA binding. Recombinant C-zinc finger domain formed not only a homo-dimer but also a multimer. Co-expression of p300 increased the formation of homo-dimer as well as the acetylation of GATA4 in HEK293T cells. The GATA4 homo-dimer was disrupted by acetyl-deficient GATA4 or HAT-deficient p300 mutant. Overexpression of 3xG4D prevented the dimerization of GATA4, but not acetylation of GATA4. The result of luciferase assay showed that overexpression of 3xG4D prevented p300/GATA-induced ANF and ET-1 promoter activities. Furthermore, overexpression of 3xG4D inhibited phenylephrine-induced cardiomyocyte hypertrophy.

Conclusions

These results suggest that GATA4 dimerization may play an important role in hypertrophy-response gene activation. Thus, it is likely that inhabitation of GATA4 dimerization become therapeutic target for cardiac hypertrophy.

P1833The c-fos mRNA expression reveals persistent myocardial stretch in the right ventricle during asphyxiated cardiac arrest

Background

Donation after circulatory death (DCD) heart transplantation has been debated over the past decades because of the shortage of donor. The right ventricular dysfunction is one of the remaining problems for clinical implication of DCD heart transplantation. DCD hearts suffering from the volume overload have a potential to aggravate the right ventricular dysfunction after heart transplantation. The c-fos mRNA is one of the “immediate” response genes to mechanical stresses, such as myocardial cell stretch, without neural and humoral factors. In this study, we assessed myocardial stretch during asphyxiated cardiac arrest using c-fos mRNA expression.

Purpose

The purpose of this study is to reveal the impact of right ventricular volume overload during asphyxiated cardiac arrest.

Methods

Male Wistar rats (8 weeks of age, n=18) were anesthetized with paralyzed ventilation. The trachea was dissected and ligated to initiate asphyxiation. Hearts were harvested at 3 time points: 0, 15 and 30 minutes after termination of the ventilation. Free walls of right and left ventricle were sectioned and immersed in RNA stabilization solution as soon as possible. Total RNA was extracted from these tissues using a guanidine thiocyanate-phenol-chloroform method and cDNA was synthesized using a reverse transcriptase. Next, we measured the quantified expression level by using the droplet digital PCR method with a probe and primers for c-fos gene. Expression of c-fos level was divided by extracted TATA binding protein (TBP) level as a control marker, the ratio of c-fos and TBP was used in analysis.

Results

In the left ventricle, the expression of c-fos rapidly increased by 15 minutes (0.81±0.24 (c-fos/TBP), p<0.05 by one-way ANOVA followed by the Dunnett's test) compared to at 0 minutes (0.21±0.06), but the expression level recovered to the baseline level at 30 minutes after termination of the ventilation (0.19±0.03). On the other hand, in the right ventricle, the c-fos expression was gradually elevated and peaked at 30 minutes (0.88±0.20, p<0.05 by the Dunnett's test) compared to at 0 minutes (0.22±0.05).

Conclusion

These results suggest that the volume overload to the right ventricle during asphyxiated cardiac arrest prolongs compared to that to the left ventricle, which may cause the right ventricular dysfunction after DCD heart transplantation.

P4998Novel GATA4 binding proteins, RbAp48/46, regulate cardiomyocyte hypertrophy with depending on the phosphorylate State of GATA4

Introduction

Cardiac hypertrophy is being recognized as a critical event during the development of heart failure. A zinc finger protein GATA4 associates with an intrinsic histone acetyltransferase p300 and regulates myocardial transcriptional activities in response to hypertrophic stimuli. Here, we show that Retinoblastoma protein (Rb)-associated protein 48 and 46 (RbAp48, RbAp46) are novel components of p300/GATA4 complex. Both RbAp48 and 46 form a repressor complex with HDACs and has been implicated in chromatin remodeling and transcriptional repression. However, the precise functional relationships among p300, GATA4, RbAp48, and RbAp46 remain unknown.

Hypothesis

We assessed the hypothesis that RbAp48/46 form a functional complex with p300/GATA4 and regulated hypertrophic responses in cardiomyocytes.

Methods and results

IP-WB using nuclear extract from rat heart demonstrated that GATA4 formed a complex with RbAp48, RbAp46, HDAC1, and HDAC2. GST pull down assay using recombinant proteins showed that GATA4 physically interacted with both RbAp48 and RbAp46 but not HDAC1 and HDAC2. Deletion mutant assay revealed that N-terminal domain of GATA4 interacted with RbAp48/46. In HEK293T cell, overexpression of RbAp48/46 recruited HDAC1/2 to GATA4, inhibited p300-induced GATA4 acetylation and suppressed p300/GATA4-dependent ANF and ET-1 promoter activations. Conversely, the knockdown of RbAp48/46 reversed these changes. Although overexpression of HDAC1/2 did not change p300/GATA4-induced these promoter activities, co-expression of HDAC1 or HDAC2 with RbAp48/46 enhanced RbAp48/46-mediated inhibitory actions. In cardiomyocytes, overexpression of RbAp48/46 significantly inhibited phenylephrine (PE)-induced GATA4 acetylation, activation of ANF and ET-1 promoters, and cardiomyocyte hypertrophy. The knockdown of RbAp48/46 reversed these changes. Moreover, the knockdown of HDAC1/2 deteriorated PE-induced hypertrophy-responsive events and did not exhibit RbAp48/46-induced inhibitory actions. Finally, MEK1/ERK-mediated S105 phosphorylation of GATA4 by PE stimulus induced the dissociation of RbAp48/46 with GATA4, the increase of p300-induced GATA4-acetylation, the synergistic activation of ANF and ET-1 promoters with p300/GATA4, and the decrease of RbAp48/46 recruitments onto the GATA element of the ANF promoter. Conversely, PD98059, a MEK1 inhibitor, treatment inhibited GATA4-phosphorylation and these changes.

Conclusion

In this study, we demonstrate that RbAp48/46 mediate the binding between GATA4 and HDAC1/2 and regulate p300/GATA4 axis. The phosphorylation of S105 GATA4 has a critical role on the dissociation of GATA4/RbAp48/46/HDAC repressor complex, the formation of 300/GATA4 activator complex, and the increase of GATA4 acetylation and hypertrophic responses. These findings suggest that RbAp48/46 may regulate hypertrophic responses involved in modulating the posttranslational modification crosstalk of GATA4.

Acknowledgement/Funding

This work was supported by JSPS KAKENHI Grant.