Lipid bilayer membrane permeability mechanism of the K-Ras(G12D)-inhibitory bicyclic peptide KS-58 elucidated by molecular dynamics simulations

Peptides are mid-size molecules (700-2000 g/mol) and have attracted particular interest as therapeutic modalities as they are superior in controlling protein-protein interactions, a process that is a typical drug target category, compared with small molecules (<500 g/mol). In 2020, we identified KS-58 (1333 g/mol) as a K-Ras(G12D)-inhibitory bicyclic peptide and suggested its cell membrane permeability. However, the membrane permeability mechanism had not been elucidated. In this study, we aim to clarify the mechanism by molecular dynamics (MD) simulations. Initially, we simulated the molecular conformations of KS-58 in water (a polar solvent) and in chloroform (a non-polar solvent). The identified stable conformations were significantly different in each solvent. KS-58 behaves as a chameleon-like molecule as it alters its polar surface area (PSA) depending on the solvent environment. It was also discovered that orientation of Asp's side chain is a critical energy barrier for KS-58 altering its conformation from hydrophilic to lipophilic. Taking these properties into consideration, we simulated its lipid bilayer membrane permeability. KS-58 shifted toward the inside of the lipid bilayer membrane with altering its conformations to lipophilic. When the simulation condition was set in deionized form of that carboxy group of Asp, KS-58 traveled deeper inside the cell membrane. PSA and the depth of the membrane penetration correlated. In vitro data suggested that cell membrane permeability of KS-58 is improved in weakly acidic conditions leading to partial deionization of the carboxy group. Our data provide an example of the molecular properties of mid-size peptides with membrane accessibility and propose an effective metadynamics approach to elucidate such molecular mechanisms by MD simulations.

Blockade of vasoactive intestinal peptide receptor 2 (VIPR2) signaling suppresses cyclin D1-dependent cell-cycle progression in MCF-7 cells

Vasoactive intestinal peptide (VIP) receptor 2 (VIPR2) is a G protein-coupled receptor that binds to Gαs, Gαi, and Gαq proteins to regulate various downstream signaling molecules, such as protein kinase A (PKA), phosphatidylinositol 3-kinase (PI3K), and phospholipase C. In this study, we examined the role of VIPR2 in cell cycle progression. KS-133, a newly developed VIPR2-selective antagonist peptide, attenuated VIP-induced cell proliferation in MCF-7 cells. The percentage of cells in the S-M phase was decreased in MCF-7 cells treated with KS-133. KS-133 in the presence of VIP decreased the phosphorylation of extracellular signal-regulated kinase (ERK), AKT, and glycogen synthase kinase-3β (GSK3β), resulting in a decrease in cyclin D1 levels. In MCF-7 cells stably-expressing VIPR2, KS-133 decreased PI3K activity and cAMP levels. Treatment with the ERK-specific kinase (MEK) inhibitor U0126 and the class I PI3K inhibitor ZSTK474 decreased the percentage of cells in the S phase. KS-133 reduced the percentage of cells in the S phase more than treatment with U0126 or ZSTK474 alone and did not affect the effect of the mixture of these inhibitors. Our findings suggest that VIPR2 signaling regulates cyclin D1 levels through the cAMP/PKA/ERK and PI3K/AKT/GSK3β pathways, and mediates the G1/S transition to control cell proliferation.

Juniper berry extract containing Anthricin and Yatein suppresses lipofuscin accumulation in human epidermal keratinocytes through proteasome activation, increases brightness and decreases spots in human skin

OBJECTIVE

Skin brightness and spot have a significant impact on youthful and beautiful appearance. One important factor influencing skin brightness is the amount of internal reflected light from the skin. Observers recognize the total surface-reflected light and internal reflected light as skin brightness. The more internal reflected light from the skin, the more attractive and brighter the skin appears. This study aims to identify a new natural cosmetic ingredient that increases the skin's internal reflected light, decreases spot and provides a youthful and beautiful skin appearance.

METHODS

Lipofuscin in epidermal keratinocytes, the aggregating complex of denatured proteins and peroxidized lipids, is one factor that decreases skin brightness and causes of spot. Aggregates block light transmission, and peroxidized lipids lead to skin yellowness, dullness and age spot. Lipofuscin is known to accumulate intracellularly with ageing. Rapid removal of intracellular denatured proteins prevents lipofuscin formation and accumulation in cells. We focused a proteasome system that efficiently removes intracellular denatured proteins. To identify natural ingredients that increase proteasome activity, we screened 380 extracts derived from natural products. The extract with the desired activity was fractionated and purified to identify active compounds that lead to proteasome activation. Finally, the efficacy of the proteasome-activating extract was evaluated in a human clinical study.

RESULTS

We discovered that Juniperus communis fruits (Juniper berry) extract (JBE) increases proteasome activity and suppresses lipofuscin accumulation in human epidermal keratinocytes. We found Anthricin and Yatein, which belong to the lignan family, to be major active compounds responsible for the proteasome-activating effect of JBE. In a human clinical study, an emulsion containing 1% JBE was applied to half of the face twice daily for 4 weeks, resulting in increased internal reflected light, brightness improvement (L-value) and reduction in yellowness (b-value) and spot in the cheek area.

CONCLUSION

This is the first report demonstrating that JBE containing Anthricin and Yatein decreases lipofuscin accumulation in human epidermal keratinocytes through proteasome activation, increases brightness and decreases surface spots in human skin. JBE would be an ideal natural cosmetic ingredient for creating a more youthful and beautiful skin appearance with greater brightness and less spot.

ATNAS: Automatic Termination for Neural Architecture Search

Neural architecture search (NAS) is a framework for automating the design process of a neural network structure. While the recent one-shot approaches have reduced the search cost, there still exists an inherent trade-off between cost and performance. It is important to appropriately stop the search and further reduce the high cost of NAS. Meanwhile, the differentiable architecture search (DARTS), a typical one-shot approach, is known to suffer from overfitting. Heuristic early-stopping strategies have been proposed to overcome such performance degradation. In this paper, we propose a more versatile and principled early-stopping criterion on the basis of the evaluation of a gap between expectation values of generalisation errors of the previous and current search steps with respect to the architecture parameters. The stopping threshold is automatically determined at each search epoch without cost. In numerical experiments, we demonstrate the effectiveness of the proposed method. We stop the one-shot NAS algorithms and evaluate the acquired architectures on the benchmark datasets: NAS-Bench-201 and NATS-Bench. Our algorithm is shown to reduce the cost of the search process while maintaining a high performance.

The VIPR2-selective antagonist KS-133 changes macrophage polarization and exerts potent anti-tumor effects as a single agent and in combination with an anti-PD-1 antibody

We have previously demonstrated that KS-133 is a specific and potent antagonist of vasoactive intestinal peptide receptor 2 (VIPR2). We have also shown that vasoactive intestinal peptide-VIPR2 signaling affects the polarity and activation of tumor-associated macrophages, which is another strategy for cancer immunotherapy apart from the activation of effector T cells. In this study, we aimed to examine whether the selective blockade of VIPR2 by KS-133 changes the polarization of macrophages and induces anti-tumor effects. In the presence of KS-133, genetic markers indicative of tumor-aggressive M1-type macrophages were upregulated, and conversely, those of tumor-supportive M2-type macrophages were downregulated. Daily subcutaneous administration of KS-133 tended to suppress the growth of CT26 tumors (murine colorectal cancer-derived cells) implanted subcutaneously in Balb/c mice. To improve the pharmacological efficacy and reduce the number of doses, we examined a nanoformulation of KS-133 using the US Food and Drug Administration-approved pharmaceutical additive surfactant Cremophor® EL. KS-133 nanoparticles (NPs) were approximately 15 nm in size and stable at 4°C after preparation. Meanwhile, KS-133 was gradually released from the NPs as the temperature was increased. Subcutaneous administration of KS-133 NPs once every 3 days had stronger anti-tumor effects than daily subcutaneous administration of KS-133. Furthermore, KS-133 NPs significantly enhanced the pharmacological efficacy of an immune checkpoint-inhibiting anti-PD-1 antibody. A pharmacokinetic study suggested that the enhancement of anti-tumor activity was associated with improvement of the pharmacokinetic profile of KS-133 upon nanoformulation. Our data have revealed that specific blockade of VIPR2 by KS-133 has therapeutic potential for cancer both alone and in combination with immune checkpoint inhibitors.

Effects of medium-chain fatty acids and tributyrin supplementation in milk replacers on growth performance, blood metabolites, and hormone concentrations in Holstein dairy calves

This study aimed to evaluate the effects of triglycerides containing medium-chain fatty acids (MCT) and tributyrin (TB) supplementation in a milk replacer (MR) on growth performance, plasma metabolites, and hormone concentrations in dairy calves. Sixty-three Holstein heifer calves (body weight at 8 d of age, 41.1 ± 2.91 kg; mean ± SD) were randomly assigned to 1 of 4 experimental MR (28% crude protein and 18% fat): (1) containing 3.2% C8:0 and 2.8% C10:0 (in fat basis) without TB supplementation (CONT; n = 15), (2) containing 6.7% C8:0 and 6.4% C10:0 without TB supplementation (MCT; n = 16), (3) containing 3.2% C8:0 and 2.8% C10:0 with 0.6% (dry matter basis) TB supplementation (CONT+TB; n = 16), (4) containing 6.7% C8:0 and 6.4% C10:0 with 0.6% TB supplementation (MCT+TB; n = 16). The MR were offered at 600 g/d (powder basis) from 8 to 14 d, up to 1,300 g/d from 15 to 21 d, 1,400 g/d from 22 to 49 d, down to 700 g/d from 50 to 56 d, 600 g/d from 57 to 63 d, and weaned at 64 d of age. All calves were fed calf starter, chopped hay, and water ad libitum. The data were analyzed using a 2-way ANOVA via the fit model procedure of JMP Pro 16 (SAS Institute Inc.). Medium-chain fatty acid supplementation did not affect the total dry matter intake. However, calves that were fed MCT had greater feed efficiency (gain/feed) before weaning (0.74 ± 0.098 vs. 0.71 ± 0.010 kg/kg) compared with non-MCT calves. The MCT calves also had a lower incidence of diarrhea compared with non-MCT calves during 23 to 49 d of age and the weaning period (50 to 63 d of age; 9.2% vs. 18.5% and 10.5% vs. 17.2%, respectively). Calves fed with TB had a greater total dry matter intake during postweaning (3,465 vs. 3,232 g/d). Calves fed TB also had greater body weight during the weaning (90.7 ± 0.97 vs. 87.9 ± 1.01 kg) and postweaning period (116.5 ± 1.47 vs. 112.1 ± 1.50 kg) compared with that of non-TB calves. The plasma metabolites and hormone concentrations were not affected by MCT or TB. These results suggest that MCT and TB supplementation in the MR may improve the growth performance and gut health of dairy calves.

Deep learning in random neural fields: Numerical experiments via neural tangent kernel

A biological neural network in the cortex forms a neural field. Neurons in the field have their own receptive fields, and connection weights between two neurons are random but highly correlated when they are in close proximity in receptive fields. In this paper, we investigate such neural fields in a multilayer architecture to investigate the supervised learning of the fields. We empirically compare the performances of our field model with those of randomly connected deep networks. The behavior of a randomly connected network is investigated on the basis of the key idea of the neural tangent kernel regime, a recent development in the machine learning theory of over-parameterized networks; for most randomly connected neural networks, it is shown that global minima always exist in their small neighborhoods. We numerically show that this claim also holds for our neural fields. In more detail, our model has two structures: (i) each neuron in a field has a continuously distributed receptive field, and (ii) the initial connection weights are random but not independent, having correlations when the positions of neurons are close in each layer. We show that such a multilayer neural field is more robust than conventional models when input patterns are deformed by noise disturbances. Moreover, its generalization ability can be slightly superior to that of conventional models.

Vasoactive intestinal peptide receptor 2 signaling promotes breast cancer cell proliferation by enhancing the ERK pathway

Vasoactive intestinal peptide (VIP) receptor 2 (VIPR2) is a class B G protein-coupled receptor with the neuropeptide VIP as a ligand. Increased VIPR2 mRNA expression and/or VIPR2 gene copy number has been documented in several cancers including breast carcinoma. However, the pathophysiological role of increased VIPR2 in the proliferation of breast cancer cells remains largely unknown. In this study, we found that VIPR2 overexpression in MCF-7 and MDA-MB-231 cells, human breast cancer cell lines, promoted cell proliferation. Increased VIPR2 also exacerbated intraperitoneal proliferation of breast cancer MDA-MB-231 cells in a tumor nude mouse model in vivo. Treatment with KS-133, a VIPR2-selective antagonist peptide, significantly inhibited VIP-induced cell proliferation in VIPR2-overexpressing MCF-7 and MDA-MB-231 cells. Overexpressed VIPR2 caused increases in the levels of cAMP and phosphorylated extracellular signal-regulated kinase (ERK), which involves a VIPR2 signaling pathway through Gs protein. Additionally, phosphorylation of vasodilator-stimulated phosphoprotein (Ser157) and cAMP response element binding protein (Ser133) in VIPR2-overexpressing MCF-7 cells was greater than that in control cells, suggesting the increased PKA activity. Moreover, an inhibitor of mitogen-activated protein kinase kinase, U0126, attenuated tumor proliferation in exogenous VIPR2-expressing MCF-7 and MDA-MB-231 cells at the same level as observed in EGFP-expressing cells treated with U0126. Together, these findings suggest that VIPR2 controls breast tumor growth by regulating the cAMP/PKA/ERK signaling pathway, and the excessive expression of VIPR2 may lead to an exacerbation of breast carcinoma.

Formation and evolution of carbonaceous asteroid Ryugu: Direct evidence from returned samples

Samples of the carbonaceous asteroid Ryugu were brought to Earth by the Hayabusa2 spacecraft. We analyzed 17 Ryugu samples measuring 1 to 8 millimeters. Carbon dioxide-bearing water inclusions are present within a pyrrhotite crystal, indicating that Ryugu's parent asteroid formed in the outer Solar System. The samples contain low abundances of materials that formed at high temperatures, such as chondrules and calcium- and aluminum-rich inclusions. The samples are rich in phyllosilicates and carbonates, which formed through aqueous alteration reactions at low temperature, high pH, and water/rock ratios of <1 (by mass). Less altered fragments contain olivine, pyroxene, amorphous silicates, calcite, and phosphide. Numerical simulations, based on the mineralogical and physical properties of the samples, indicate that Ryugu's parent body formed ~2 million years after the beginning of Solar System formation.

Arnica montana L. extract containing 6-O-methacryloylhelenalin and 6-O-isobutyrylhelenalin accelerates growth and differentiation of human subcutaneous preadipocytes and leads volumizing of skin

OBJECTIVE

An important factor in the aging of the face is a reduction in the volume of adipose tissue. This reduction in adipose tissue contributes to decreased skin elasticity, which is also part of the aging process. Overall, these lead to wrinkle formation. Fat injection is a common means of addressing this issue and is used to reduce the effects of aging on the face and to increase the fullness of the lips and breasts. However, fat injection is an invasive surgical procedure. This study aimed to discover novel cosmetic ingredients that increase the volume of subcutaneous (pre)adipocytes to create the appearance of more youthful skin.

METHODS

We focused on the number of subcutaneous preadipocytes and the accumulation of lipid droplets. To discover natural ingredients that increase both of these, extracts of 380 natural products were prepared and screened for their effects on both growth and differentiation (i.e., lipid droplet accumulation) of human subcutaneous preadipocytes. One extract was found to have the desired effects, and this was further studied to determine the active compounds. We then evaluated its efficacy in a human clinical study.

RESULTS

We found that Arnica montana L. flower extract (AFE) accelerates both the growth and the differentiation of human subcutaneous preadipocytes. AFE was found to significantly increase the volume of adipocyte spheroids. The active compounds 6-O-methacryloylhelenalin and 6-O-isobutyrylhelenalin were found to be responsible for the effects of AFE on preadipocytes. In a human clinical study, gels containing 1% AFE successfully enhanced the volume of the lips and face with reduction of wrinkles with no adverse reactions.

CONCLUSION

This is the first report to demonstrate that AFE and the included compounds, 6-O-methacryloylhelenalin and 6-O-isobutyrylhelenalin, act on preadipocytes. AFE would be ideal for use in products that plump the face to reduce wrinkles and create a more youthful appearance.

Development of the vasoactive intestinal peptide receptor 2 (VIPR2) antagonist peptide for the treatment of schizophrenia

Schizophrenia affects approximately 24 million people worldwide. Existing medications for the treatment of schizophrenia work primarily by improving positive symptoms such as agitation, hallucinations, delusions, and aggression. They possess common mechanism of action (MOA), blocking to neurotransmitter receptors such as dopamine, serotonin, and adrenaline receptors. Although multiple agents are available for the treatment of schizophrenia, the majority do not address negative symptoms or cognitive dysfunction. In other cases, patients have drug-related adverse effects. The vasoactive intestinal peptide receptor 2 (VIPR2, also known as VPAC2 receptor) might be an attractive drug target for the treatment of schizophrenia because both clinical and preclinical studies have demonstrated a strong link between high expression/overactivation of VIPR2 and schizophrenia. Despite these backgrounds, the proof-of-concept of VIPR2 inhibitors has not been examined clinically. A reason might be that VIPR2 belongs to class-B GPCRs, and the discovery of small-molecule drugs against class-B GPCRs is generally difficult. We have developed a bicyclic peptide KS-133, which shows VIPR2 antagonist activity and suppresses cognitive decline in a mouse model relevant to schizophrenia. KS-133 has a different MOA from current therapeutic drugs and exhibits high selectivity for VIPR2 and potent inhibitory activity against a single-target molecule. Therefore, it may contribute to both the development of a novel drug candidate for the treatment of psychiatric disorders such as schizophrenia and acceleration of basic studies on VIPR2.

Generation of KS-487 as a novel LRP1-binding cyclic peptide with higher affinity, higher stability and BBB permeability

The blood–brain barrier (BBB) is a major hurdle in drug discovery for central nervous system (CNS) disorders. Particularly, mid-size molecules and macromolecules (e.g., peptides and antibodies) that modulate intractable drug targets such as protein-protein interaction are prevented from entering the CNS via BBB. The receptor-mediated transcytosis (RMT) pathway has been examined to deliver these molecules to CNS. Among the receptors, low-density lipoprotein receptor-related protein 1 (LRP1) has been emerged as one of the promising receptors for RMT. Although several LRP1-binding peptides have been reported, no drugs are available on the market based on the combination of reported LRP1-binding peptides and therapeutic molecules. One reason may be stability in vivo and BBB-permeability of the peptides. The present study aims to identify a novel LRP1-binding peptide for RMT, where we successfully generated a 15-mer cyclic peptide named KS-487. It explicitly bound to Cluster 4 domain of LRP1 with the binding EC₅₀ value of 10.5 nM and was relatively stable in mouse plasma within 24 h. Moreover, its high BBB permeability was demonstrated using in vitro rat and monkey BBB models. By 24 h incubation, 13% and 17% of the added amount of KS-487 (10 μM) penetrated rat BBB and monkey BBB, respectively. KS-487 would be a potential candidate for the LRP1-mediated transcytosis-based drug delivery to CNS, as these values were significantly higher than those of the known LRP1-binding peptides—Angiopep-2 and L57.

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KS-487 exhibited higher BBB-permeability in vitro than Angiopep-2 and L57.

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About 28% of KS-487 remained intact after 24 h incubation in mouse plasma.

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About 15% of KS-487 crossed in vitro rat- and monkey-BBBs after 24 h incubation.

Intravenous vagal stimulation catheter, JOHAKU, rapidly decreases heart rate and myocardial oxygen consumption without worsening hemodynamics

Background

Rapid reduction of heart rate (HR) is the most evident physiological response of vagal nerve stimulation (VNS). Since HR reduction is the most potent factor to decrease myocardial oxygen consumption rate (MVO2), the appropriate VNS can exert cardio-protective effects. It is also known that VNS reduces inflammation, oxidative stress, and sympathetic overload. In addition, the VNS during ischemia-reperfusion is known to attenuate myocardial damage by studies in various animal species. Despite the presence of preclinical evidence of VNS benefits, the lack of the device has limited the translation of this technology to clinical practice. We have recently developed an intravenous VNS catheter (JOHAKU, Neuroceuticals Inc.) that can stimulate the right vagal nerve via superior vena cava (SVC) (Figure 1) on temporary basis.

Purpose

We aimed to confirm the feasibility of JOHAKU as a device to modulate heart rate and MVO2 rapidly by a canine experiment.

Methods

In eight beagle dogs, JOHAKU was inserted from the right femoral vein and placed at the SVC level. The stimulation intensity was adjusted to 10–20 V (20 Hz). We simultaneously recorded electrocardiogram and intraarterial blood pressure (BP). In three of eight dogs, we measured the left anterior descending coronary artery flow and oxygen saturations of arterial and coronary sinus blood to calculate MVO2. We compared HR, BP, and MVO2 during JOHAKU stimulation to ones at baseline.

Results

As shown in Figure 2, JOHAKU attenuated HR immediately after stimulation. Compared with baseline, JOHAKU significantly reduced HR (baseline: 135±13 vs. 5 min on stimulation: 107±13 bpm, p&lt;0.05), and did not affect mean BP significantly (96.2±22.8 vs. 89.4±26.6 mmHg, P=0.59). HR promptly recovered to baseline level after JOHAKU stopped. JOHAKU also reduced MVO2 (0.57±0.43 vs. 0.48±0.38 ml/min, p&lt;0.05).

Conclusion

JOHAKU rapidly attenuated cardiac metabolism burden via the rapid HR reduction. The controllability of HR by JOHAKU without affecting BP enables us to apply the VNS even for patients with hemodynamic instability, such as heart failure and acute myocardial infarction.

Funding Acknowledgement

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Japan Agency for Medical and Research Development

Prevalence and distribution of non-pulmonary vein atrial fibrillation triggers in real-world clinical settings

Background

Epidemiology of non-pulmonary vein (PV) triggers of atrial fibrillation (AF) is not fully known.

Purpose

This study aimed to clarify the prevalence and distribution of non-PV triggers in real-world clinical settings of AF catheter ablation.

Methods

One-thousand and twenty patients undergoing AF ablations were retrospectively analyzed (mean age 65 years old, 702 males (69%), 506 paroxysmal and 514 non-paroxysmal). Induction and observation of AF triggers were attempted using intravenous isoproterenol/adenosine triphosphate and repeated direct current cardioversion during AF in each session. Documentable non-PV AF triggers were characterized in the studied population. Premature atrial contractions that did not initiate AF were excluded.

Results

A hundred and twenty-six non-PV triggers were documented in 108 patients (10.6%). Non-PV trigger was documented in 6.3% of 1st session cases, whereas 30.9% of recurrent cases undergoing multiple sessions (p&lt;0.0001). Left atrial (LA) posterior wall was the most prevalent site (N=34), followed by 30 intra-atrial septum (IAS), 29 superior vena cava (SVC), 13 crista terminalis, 7 right atrial (RA) free wall, 6 LA anterior wall, 3 coronary sinus (CS), 3 left atrial appendage, and 1 persistent left superior vena cava (LSVC). We classified those non-PV triggers into 4 groups; 43 LA, 33 thoracic veins (SVC, CS and LSVC), 30 IAS and 20 RA. Thoracic vein/RA origins were more prevalently detected in paroxysmal AF cases (57%) compared to non-paroxysmal AF (28%) (p&lt;0.01). Conversely, LA origin was more prevalently detected in non-paroxysmal AF cases (48%) compared to paroxysmal AF (20%) (p&lt;0.01).

Conclusions

Prevalence of non-PV trigger in cases undergoing multiple sessions is extremely high, suggesting a particular importance of non-PV trigger targeting in patients with recurrent AF undergoing 2nd or 3rd ablation sessions. Progressive nature of AF with newly generated AF triggers should be under consideration. Distributions of non-PV triggers are largely different between paroxysmal and non-paroxysmal AF. These findings may help ablation strategy regarding non-PV trigger targeting in practice.

Funding Acknowledgement

Type of funding sources: None.

Vasoactive intestinal peptide–VIPR2 signaling regulates tumor cell migration

Phosphoinositide metabolism is critically involved in human cancer cell migration and metastatic growth. The formation of lamellipodia at the leading edge of migrating cells is regulated by metabolism of the inositol phospholipid PI(4,5)P₂ into PI(3,4,5)P₃. The synthesized PI(3,4,5)P₃ promotes the translocation of WASP family verprolin homologous protein 2 (WAVE2) to the plasma membrane and regulates guanine nucleotide exchange factor Rac-mediated actin filament remodeling. Here, we investigated if VIPR2, a receptor for vasoactive intestinal peptide (VIP), has a potential role in regulating cell migration via this pathway. We found that silencing of VIPR2 in MDA-MB-231 and MCF-7 human breast cancer cells inhibited VIP-induced cell migration. In contrast, stable expression of exogenous VIPR2 promoted VIP-induced tumor cell migration, an effect that was inhibited by the addition of a PI3-kinase (PI3K)γ inhibitor or a VIPR2-selective antagonist. VIPR2 stably-expressing cells exhibited increased PI3K activity. Membrane localization of PI(3,4,5)P₃ was significantly attenuated by VIPR2-silencing. VIPR2-silencing in MDA-MB-231 cells suppressed lamellipodium extension; in VIPR2-overexpressing cells, VIPR2 accumulated in the cell membrane on lamellipodia and co-localized with WAVE2. Conversely, VIPR2-silencing reduced WAVE2 level on the cell membrane and inhibited the interaction between WAVE2, actin-related protein 3, and actin. These findings suggest that VIP–VIPR2 signaling controls cancer migration by regulating WAVE2-mediated actin nucleation and elongation for lamellipodium formation through the synthesis of PI(3,4,5)P₃.

The K-Ras(G12D)-inhibitory peptide KS-58 suppresses growth of murine CT26 colorectal cancer cell-derived tumors

Mutations in the cell proliferation regulator K-Ras are found with a variety of cancer types, so drugs targeting these mutant proteins could hold great clinical potential. Very recently, a drug targeting the K-Ras(G12C) mutant observed in lung cancer gained regulatory approval and several clinical trials are currently underway to examine the efficacy of this agent when combined with other drugs such as a monoclonal antibody inhibitor of programmed cell death 1 receptor (anti-PD-1). Alternatively, there are currently no approved drugs targeting K-Ras(G12D), the most common cancer-associated K-Ras mutant. In 2020, we described the development of the K-Ras(G12D) inhibitory bicyclic peptide KS-58 and presented evidence for anticancer activity against mouse xenografts derived from the human pancreatic cancer cell line PANC-1 stably expressing K-Ras(G12D). Here, we show that KS-58 also possess anticancer activity against mouse tumors derived from the colorectal cancer cell line CT26 stably expressing K-Ras(G12D). Further, KS-58 treatment reduced phosphorylation of ERK, a major downstream signaling factor in the Ras pathway, confirming that KS-58 inhibits K-Ras(G12D) function. Unexpectedly; however, KS-58 did not show additive or synergistic anticancer activity with mouse anti-PD-1. Morphological analysis and immunostaining demonstrated no obvious differences in CD8⁺ cells infiltration or PD-L1 expression levels in CT26-derived tumors exposed to monotherapy or combination treatment. Nonetheless, KS-58 demonstrated reasonable stability in blood (t_1/2 ≈ 30 min) and no obvious systemic adverse effects, suggesting clinical potential as a lead molecule against colorectal cancer.

Pebbles and sand on asteroid (162173) Ryugu: In situ observation and particles returned to Earth

The Hayabusa2 spacecraft investigated the C-type (carbonaceous) asteroid (162173) Ryugu. The mission performed two landing operations to collect samples of surface and subsurface material, the latter exposed by an artificial impact. We present images of the second touchdown site, finding that ejecta from the impact crater was present at the sample location. Surface pebbles at both landing sites show morphological variations ranging from rugged to smooth, similar to Ryugu's boulders, and shapes from quasi-spherical to flattened. The samples were returned to Earth on 6 December 2020. We describe the morphology of >5 grams of returned pebbles and sand. Their diverse color, shape, and structure are consistent with the observed materials of Ryugu; we conclude that they are a representative sample of the asteroid.

DAJIN enables multiplex genotyping to simultaneously validate intended and unintended target genome editing outcomes

Genome editing can introduce designed mutations into a target genomic site. Recent research has revealed that it can also induce various unintended events such as structural variations, small indels, and substitutions at, and in some cases, away from the target site. These rearrangements may result in confounding phenotypes in biomedical research samples and cause a concern in clinical or agricultural applications. However, current genotyping methods do not allow a comprehensive analysis of diverse mutations for phasing and mosaic variant detection. Here, we developed a genotyping method with an on-target site analysis software named Determine Allele mutations and Judge Intended genotype by Nanopore sequencer (DAJIN) that can automatically identify and classify both intended and unintended diverse mutations, including point mutations, deletions, inversions, and cis double knock-in at single-nucleotide resolution. Our approach with DAJIN can handle approximately 100 samples under different editing conditions in a single run. With its high versatility, scalability, and convenience, DAJIN-assisted multiplex genotyping may become a new standard for validating genome editing outcomes.

Generation of KS-133 as a Novel Bicyclic Peptide with a Potent and Selective VIPR2 Antagonist Activity that Counteracts Cognitive Decline in a Mouse Model of Psychiatric Disorders

Worldwide, more than 20 million people suffer from schizophrenia, but effective and definitive new therapeutic drugs/treatments have not been established. Vasoactive intestinal peptide receptor 2 (VIPR2) might be an attractive drug target for the treatment of schizophrenia because both preclinical and clinical studies have demonstrated a strong link between high expression/overactivation of VIPR2 and schizophrenia. Nevertheless, VIPR2-targeting drugs are not yet available. VIPR2 is a class-B G protein-coupled receptor that possesses high structural homology to its subtypes, vasoactive intestinal peptide receptor 1 (VIPR1) and pituitary adenylate cyclase-activating polypeptide type-1 receptor (PAC1). These biological and structural properties have made it difficult to discover small molecule drugs against VIPR2. In 2018, cyclic peptide VIpep-3, a VIPR2-selective antagonist, was reported. The aim of this study was to generate a VIpep-3 derivative for in vivo experiments. After amino acid substitution and structure optimization, we successfully generated KS-133 with 1) a VIPR2-selective and potent antagonistic activity, 2) at least 24 h of stability in plasma, and 3) in vivo pharmacological efficacies in a mouse model of psychiatric disorders through early postnatal activation of VIPR2. To the best of our knowledge, this is the first report of a VIPR2-selective antagonistic peptide that counteracts cognitive decline, a central feature of schizophrenia. KS-133 may contribute to studies and development of novel schizophrenia therapeutic drugs that target VIPR2.

A selective delta opioid receptor agonist SNC80, but not KNT-127, induced tremor-like behaviors via hippocampal glutamatergic system in mice

Although delta opioid receptors (DOP) are now known to play a major role in modulating chronic pain and controlling emotional processes, unfortunately, some DOP agonists, such as SNC80, reportedly produced convulsive-like behaviors manifesting as tremor-like behaviors in a preclinical study. Therefore, these induced convulsions limit the progress of the clinical development of DOP agonists. However, mechanisms underlying DOP-induced convulsant activity remain unclarified. Thus, the study aimed to elucidate mechanisms that could cause tremor-like behaviors of SNC80. These drugs were microinjected into the ventral hippocampus CA3 (vCA3), amygdala (AMY), and insular cortex (IC) of mice. In addition, we examined the extracellular glutamate levels after DOP agonist local treatment. Microinjection of SNC80 into the vCA3 increased the number of tremor-like behaviors and extracellular glutamate levels but did not cause tremor-like behaviors in mice when microinjected into IC and AMY. Pretreatment with α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA)/kainite receptor antagonist CNQX into vCA3 totally inhibited the SNC80-induced increases in tremor-like behaviors. In contrast, another DOP agonist, KNT-127, did not cause tremor-like behaviors in any of the tested brain areas. Further, the extracellular glutamate levels in the hippocampus were significantly lower in the KNT-127-treated mice than in the SNC80-treated mice. Our results showed that the administration of SNC80, but not KNT-127, into vCA3 induced tremor-like behaviors by activating glutamatergic neurons in mice. We propose that KNT-127 should be further studied clinically as a DOP agonist that is expected to have a low risk for convulsions than those resulting in antinociceptive and antidepressant effects.

Presence of low voltage area predicts atrial tachyarrhythmia inducibility with atrial burst pacing after pulmonary vein isolation

Background

Induction of atrial fibrillation (AF)/atrial tachycardia (AT) by atrial burst pacing following ablation procedure may reflect the presence of residual substrates in the atria that maintain AF. However, the relation between the inducibility and left atrial low voltage area (LVA) has not been established.

Methods

Fifty-nine patients (65 years old, 43 males) with persistent AF who underwent pulmonary vein isolation (PVI)-based ablation were studied. All patients underwent left atrial voltage mapping during sinus rhythm and atrial burst pacing after PVI. Atrial burst pacing was performed with 30-beat at an amplitude of 10V from the ostium of the coronary sinus; increasing from 240 to 320 ppm in steps of 20 ppm or failure to 1:1 atrial capture. Inducibility was defined as AF/AT lasting more than 5 minutes following burst pacing. Left atrial LVA and other co-variates were analyzed with regard to burst pacing positivity.

Results

AF/AT was induced by burst pacing in 23 patients (39%). Univariate analysis revealed that past history of stroke, CHADS2 score and presence of left atrial LVA were significantly associated with the inducibility of AF/AT. Multivariate analysis revealed that only the presence of LVA was associated with the inducibility (OR 1.5: per 10% increase; p=0.04). We focused on the relationship between the extent of LVA and burst positivity. AF/AT inducibility increased as low voltage area increased, and it was as high as 72.7% when low voltage area was more than 20% (P&lt;0.05). Interestingly, induced arrhythmia type was AT rather than AF when low voltage area was more than 20%.

Conclusions

Presence of left atrial LVA is an independent predictor of atrial tachyarrhythmia inducibility after PVI in patients with persistent AF. A large amount of low voltage area is related to AT inducibility rather than AF.

Extent of LVA and burst positivity

Funding Acknowledgement

Type of funding source: None

Four-Types of IIT-Induced Group Integrity of Plecoglossus altivelis

Integrated information theory (IIT) was initially proposed to describe human consciousness in terms of intrinsic-causal brain network structures. Particularly, IIT 3.0 targets the system's cause-effect structure from spatio-temporal grain and reveals the system's irreducibility. In a previous study, we tried to apply IIT 3.0 to an actual collective behaviour in Plecoglossus altivelis. We found that IIT 3.0 exhibits qualitative discontinuity between three and four schools of fish in terms of Φ value distributions. Other measures did not show similar characteristics. In this study, we followed up on our previous findings and introduced two new factors. First, we defined the global parameter settings to determine a different kind of group integrity. Second, we set several timescales (from Δ t = 5 / 120 to Δ t = 120 / 120 s). The results showed that we succeeded in classifying fish schools according to their group sizes and the degree of group integrity around the reaction time scale of the fish, despite the small group sizes. Compared with the short time scale, the interaction heterogeneity observed in the long time scale seems to diminish. Finally, we discuss one of the longstanding paradoxes in collective behaviour, known as the heap paradox, for which two tentative answers could be provided through our IIT 3.0 analysis.

Abstract B35: Discovery of K-Ras(G12D)-targeting peptide KRpep-2d and its optimization strategy

Mutated Ras proteins play important roles in cell differentiation, proliferation, and survival of various cancers, especially mutations at residue Gly12 where G12D in K-Ras is the most frequent mutation. Although over 30 years have passed since the discovery of mutated Ras in human cancers, effective drug targeting to Ras has not been marketed. Very recently, KRpep-2d, an artificial cyclic peptide, was discovered as a first selective inhibitor to K-Ras(G12D) by phage display technology. KRpep-2d possesses low nanomol level activity in cell-free assays and shows preferable target selectivity in cell-based assay. In this presentation, I review the biochemical activity, biophysical activity, and SAR of KRpep-2d. In addition, I will discuss a strategy to brush up KRpep-2d for its therapeutic use.

Citation Format: Kotaro Sakamoto. Discovery of K-Ras(G12D)-targeting peptide KRpep-2d and its optimization strategy [abstract]. In: Proceedings of the AACR Special Conference on Targeting RAS-Driven Cancers; 2018 Dec 9-12; San Diego, CA. Philadelphia (PA): AACR; Mol Cancer Res 2020;18(5_Suppl):Abstract nr B35.

Finding continuity and discontinuity in fish schools via integrated information theory

Collective behaviours are known to be the result of diverse dynamics and are sometimes likened to living systems. Although many studies have revealed the dynamics of various collective behaviours, their main focus has been on the information processing performed by the collective, not on interactions within the collective. For example, the qualitative difference between three and four elements in a system has rarely been investigated. Tononi et al. proposed integrated information theory (IIT) to measure the degree of consciousness Φ. IIT postulates that the amount of information loss caused by the minimum information partition is equivalent to the degree of information integration in the system. This measure is not only useful for estimating the degree of consciousness but can also be applied to more general network systems. Here, we obtained two main results from the application of IIT (in particular, IIT 3.0) to the analysis of real fish schools (Plecoglossus altivelis). First, we observed that the discontinuity on 〈Φ(N)〉 distributions emerges for a school of four or more fish. This transition was not observed by measuring the mutual information or the sum of the transfer entropy. We also analysed the IIT on Boids simulations with respect to different coupling strengths; however, the results of the Boids model were found to be quite different from those of real fish. Second, we found a correlation between this discontinuity and the emergence of leadership. We discriminate leadership in this paper from its traditional meaning (e.g. defined by transfer entropy) because IIT-induced leadership refers not to group behaviour, as in other methods, but the degree of autonomy (i.e. group integrity). These results suggest that integrated information Φ can reveal the emergence of a new type of leadership which cannot be observed using other measures.

Commissioning of high current H+/D+ ion beams for the prototype accelerator of the International Fusion Materials Irradiation Facility

The Linear IFMIF (International Fusion Materials Irradiation Facility) Prototype Accelerator (LIPAc) is aiming at demonstrating the low energy section of a 40 MeV/125 mA IFMIF deuteron accelerator up to 9 MeV with a full beam current in cw operation. For such a high-power beam, the LIPAc injector is required to produce a 100 keV D⁺ beam with 140 mA and match it for injection into the Radio Frequency Quadrupole (RFQ) accelerator. The injector is designed by CEA-Saclay based on the high intensity light ion source (SILHI). In 2019, the commissioning of the RFQ to demonstrate the D⁺ beam acceleration at a low duty cycle (0.1%) was conducted. A nominal beam current of 125 mA D⁺ beam was accelerated up to 5 MeV through the RFQ successfully. The LIPAc injector fully satisfied the requirements for RFQ beam commissioning at the pulse mode.

P26 Soluble programed cell death ligand-1 is associated with acute coronary syndrome

Background

Immune checkpoint by programmed cell death (PD)-1 and its ligand (PD-L1) play crucial role in T cell tolerance toward vascular wall antigens. PD-L1 is widely expressed on a number of cells including immune cells and vascular endothelium. It was reported that increased expression of PD-L1 in dendritic cells implicates upregulated inflammation in atherosclerotic lesions that is associated with plaque instability. Although plaque rupture in coronary atherosclerosis is an important pathogenesis of acute coronary syndrome (ACS), the association between PD-L1 and ACS is still unknown.

Purpose

We hypothesize that circulating PD-L1 might be associated with ACS, reflecting endothelial damage and coronary plaque rupture. To elucidate this hypothesis, we compared serum levels of soluble PD-L1 (sPD-L1) in stable coronary artery disease (CAD) patients with those in ACS patients.

Methods

Serum levels of sPD-L1 were measured by using commercially available ELISA kit (Human PD-L1/B7-H1 DuoSet, R&D Systems) in consecutive patients with CAD admitted to our University Hospital from February 2016 to March 2017. Patients with any malignant disease or severe inflammatory disease were excluded from this study. Serum levels of sPD-L1 and clinical backgrounds were compared between stable-CAD and ACS patients.

Results

In total, 269 patients with CAD were enrolled (28 cases [10.4 %] with ACS and 241 cases [89.6 %] with stable-CAD). PD-L1 had no correlation to C-reactive protein, cardiac troponin, and classical atherosclerotic risks such as age, body mass index, estimated glomerular filtration rate, low density lipoprotein cholesterol (LDL-C), high density lipoprotein cholesterol, and hemoglobin A1c. Although age, sex, history of smoking, and the prevalences of hypertension, diabetes mellitus and dyslipidemia were comparable between both groups, the level of LDL-C was significantly higher in patients with ACS compared with those with stable-CAD (94.0 [77.0–112.0] mg/dL vs. 78.5 [65.0–97.0] mg/dL, P = 0.008). Also serum level of sPD-L1 was significantly increased in patients with ACS compared with those with stable-CAD (106.1 [60.9–157.7] pg/mL vs. 64.8 [30.9–102.5] pg/mL, P = 0.003). Univariate logistic regression analysis identified that serum levels of both sPD-L1 and LDL-C were independently associated with ACS. Moreover, multivariable logistic regression analysis with factors from univariate analysis identified that serum level of sPD-L1 was significantly and independently associated with ACS (odds ratio: 1.006, 95 % confidence interval: 1.001–1.012, P = 0.03).

Conclusions

This is the first study to elucidate that the increased serum levels of sPD-L1 was associated with ACS. This study suggests that sPD-L1 could be a risk marker and therapeutic target for ACS.

P6513Temporal trends in coronary intervention strategies and the impact on one-year clinical events: data from a Japanese multi-center real-world cohort study

Background

While it is clear that device technology of percutaneous coronary intervention (PCI) has advanced over the course of the last 40 years and the evidence for improvements in the efficacy of PCI is clear, it is less clear whether the prognosis following PCI continues to improve year by year.

Methods

The Kumamoto Intervention Conference Study Real-World Registry is a multi-center registry that enrolls consecutive patients undergoing PCI in 17 centers in Kyushu area, Japan. To elucidate the clinical impact of recent changes in treatment strategies, 8,841 consecutive participants (historical PCI: n=4,038, enrolled between January 2013 and December 2014, and current PCI: n=4,803, between January 2015 and March 2017) with 1-year follow-up data were analysed. Baseline demographic data, cardiovascular risk factors, and the medication being taken at discharge were documented. The primary endpoint was defined as a major adverse cardiac event (MACE), comprising cardiovascular death or non-fatal MI, including stent thrombosis (ST), occurring within 1 year of PCI.

Results

Regarding the relationships between presenting symptoms and PCI status, ACS, STEMI, NSTEMI, and UAP were similarly common, but the proportion of patients with multi-vessel disease was lower and the proportion with type B2/C lesions was higher in the current PCI group (p=0.004 and p<0.001, respectively). The prevalences of left main trunk lesions and Killip classes III or IV were comparable between the groups, but in-stent restenotic lesions were significantly more frequent in the historical PCI group (p<0.001). In addition to the change in the DAPT regimen, more optimal medical therapy was introduced during this time period, including the use of β-blockers, ACE-Is, and statins.

The incidences of MACE were comparable between historical PCI and current PCI (2.2% vs. 2.1%, p=0.693), even though complex lesions were more frequent during the more recent period. During this period, the use of radial approaches, drug eluting stents, and coronary imaging increased, but the use of intra-aortic balloon pumping (IABP) or thromboaspiration decreased. The incidences of major adverse cardiac or cerebrovascular events (MACCE), cardiac death, non-fatal MI, and stent thrombosis were similar between the historical and current periods (Figure). Multivariate analysis for overall patients, after adjustment, showed that multi-vessel disease, type B2/C lesions, ACS, and DES use were significant independent predictors of MACE.

Figure 1. Comparison of Clinical Events

Conclusion

An improvement in the prognosis associated with PCI has not occurred in recent years. However, the lesions being treated are becoming more complex, and the selection of evidence-based approaches, the use of coronary imaging, and the optimal medication treatments may have contributed to comparable outcomes being maintained.

Acknowledgement/Funding

Daiichi Sankyo Co., Ltd. Japan.

3285Impact of intravascular ultrasound-guided percutaneous coronary intervention in patients with diabetes mellitus and chronic kidney disease

Background

Several studies have shown favorable results using IVUS-guided PCI. Nevertheless, patient background in which use of IVUS is effective is not well elucidated. Patients with diabetes mellitus (DM) or chronic kidney disease (CKD) tend to have complex coronary artery lesions. We sought to assess the impact of IVUS guidance on clinical outcomes in these patients.

Methods

Kumamoto Intervention Conference Study is a multicenter registry which has enrolled consecutive patients who underwent PCI in 16 centers in Japan. Between August 2008 and March 2014, 11,195 consecutive patients were enrolled in this registry. To elucidate the efficacy of IVUS usage in DM and CKD patients, 10,822 consecutive subjects with 1-year follow-up data were analyzed. In this patient population, 69.2% (n=7,493) of patients were treated with IVUS-guided PCI. Patients were divided into 4 groups: the No Risk Group, the DM only Group, the CKD only Group, and the DM+CKD Group.

Results

Maximum stent diameter, post dilatation rate, usage of distal protection device, and rotational atherectomy rate were significantly higher in the IVUS-guided PCI patients in all 4 groups. 1-year MACE (cardiovascular death, non-fatal myocardial infarction, and MI with stent thrombosis) was significantly lower in the IVUS-guided PCI patients than angiography-guided PCI patients in each subset, except for the No Risk Group. In contrast to angiography-guided PCI patients, there were no significant differences among the 4 groups as regards 1-year MACE in the IVUS-guided PCI patients except for the DM+CKD Group. In multiple regression analysis, IVUS usage was an independent negative predictor for 1-year MACE in the DM only Group (HR=0.374, 95% CI 0.194–0.719, p=0.003) and in the CKD only Group (HR=0.604, 95% CI 0.379–0.962, p=0.010). When the No Risk Group was used as a reference, the HR has increased according to increased risk factors in the angiography-guided PCI patients, but such tendency was not necessarily observed in the IVUS-guided PCI patients (Table).

Risk Stratification of DM and CKD Variable IVUS-Guided PCI Angiography-Guided PCI HR 95% CI P HR 95% CI P The No Risk Group Reference – – Reference – –   vs. the DM only Group 0.627 0.321–1.227 0.173 2.036 1.090–3.804 0.026   vs. the CKD only Group 1.334 0.795–2.237 0.275 2.730 1.541–4.836 0.001   vs. the DM+CKD Group 2.114 1.287–3.474 0.014 2.225 1.160–4.266 0.016

Conclusion

The efficacy of IVUS usage as regards 1-year MACE was confirmed in DM and CKD patients, but not observed in patients without them or in the combination of DM and CKD patients.

Acknowledgement/Funding

None

P2613Clinical significance of brachial-ankle pulse wave velocity in patients with heart failure with reduced left ventricular ejection fraction

Background

Heart failure (HF) is characterized as a complex syndrome of structural and functional cardiac disorder that impair ventricular filling and/or blood ejection. Peripheral arterial disease (PAD) is accompanied by systemic inflammation and is frequently associated with other cardiovascular diseases. Although PAD and HF share cardiovascular risk and pathophysiological features, and each has been associated with increased morbidity and mortality. Pulse wave velocity (PWV) is known to be an indicator of arterial stiffness. We previously reported the prognostic significance of brachial–ankle PWV (baPWV) in patients with HF with preserved left ventricular ejection fraction. However, its association with cardiovascular outcomes in HF with reduced EF (HFrEF) and HF with mid-range EF (HFmrEF) patients remains uncertain.

Purpose

The first aim of this study was to investigate the impact of PAD on prognosis in HFrEF and HFmrEF. The second aim was to investigate the relationship between baPWV and the occurrence of cardiovascular events in patients with HFrEF and HFmrEF.

Methods

We measured ankle-brachial pressure index (ABI) and baPWV values at stable condition after optimal therapy for HF in 201 consecutive HFrEF and HFmrEF patients admitted to Kumamoto University Hospital from 2007 to 2015 who were enrolled and followed until the occurrence of cardiovascular events.

Results

The mean age of the two groups of patients was 67.5±11.8 years. The prevalence of PAD, defined as an ABI 0.9 or less, was 14% in patients. Kaplan–Meier analysis revealed that HFrEF and HFmrEF patients with PAD had a significant higher risk of total cardiovascular and HF-related events than those without PAD (P=0.03 and P=0.01, respectively). The hazard ratio (HR) between HFrEF and HFmrEF patients without PAD and those with PAD was compared after adjustment for other confounders. The probabilities of total cardiovascular and HF-related events in HFrEF and HFmrEF patients with PAD were significantly higher than those in HFrEF and HFmrEF patients without PAD (HR: 2.19; 95% CI: 1.02–4.73; P=0.04, and HR: 3.5; 95% CI: 1.27–9.66; P=0.01, respectively). Next, we divided HFrEF and HFmrEF patients without PAD into three groups according to baPWV values. In the Kaplan–Meier analysis, total cardiovascular and HF-related events in the highest baPWV group (1800 cm/s ≤ baPWV) had a significantly higher frequency than those in the mid-level baPWV group (1400 cm/s ≤ baPWV < 1800 cm/s) (P=0.007 and P=0.004, respectively) (Figure A, B). The hazard ratio (HR) between HFrEF and HFmrEF patients in the mid-level baPWV group and those with other baPWV groups was compared after adjustment for other cofounders. The probabilities of total cardiovascular and HF-related events were significantly higher in the highest baPWV group.

Conclusion

Identifying complications of PAD and measuring baPWV values in HFrEF and HFmrEF patients were useful for predicting their prognosis.

P1647Prognostic significance of circulating leukocyte subtype counts in patients with chronic heart failure

Background

Inflammation, characterized by early leukocyte recruitment, is known to be associated with vascular endothelial dysfunction and atherosclerosis. Previous studies have reported that an increased leukocyte count is a risk factor for the progression of atherosclerosis in cardiovascular diseases, and we previously reported that a high monocyte count was an independent and incremental of cardiovascular events in patients with coronary artery disease. Furthermore, previous study also reported that inflammation play a role in the pathophysiology of heart failure (HF), but few studies have evaluated the prognostic role of monocyte in patients with HF.

Purpose

To elucidate the prognostic value of monocyte in HF, we investigated the association of monocyte counts in patients with HF with their future cardiovascular events, and compared them among new categories of HF in this study.

Methods

Consecutive HF patients referred for hospitalization at Kumamoto University Hospital between 2006 and 2015 were registered. Finally, a total of 678 HF patients were enrolled in the study, and were followed prospectively until 2016 or until the occurrence of cardiovascular events. We defined high monocyte group as monocyte counts ≥360/mm3 according to previous clinical reports. We further divided HF patients into three types according to left ventricular ejection fraction (LVEF) (HF with reduced LVEF (HFrEF), HF with mid-range LVEF (HFmrEF), and HF with preserved LVEF (HFpEF)).

Results

In this study, HFrEF was 82 patients, HFmrEF was 118 patients and HFpEF was 478 patients, respectively. The average of total monocyte counts were 397±136 in HFrEF and 375±172 in HFmrEF, and 341±138 in HFpEF patients. Kaplan-Meier analysis revealed that both HFrEF and HFmrEF patients with high monocyte group (≥360 /mm3) had a significant higher risk of HF-related events (P=0.03 and P=0.02, respectively) but not of total cardiovascular events compared with those with low monocyte groups (<360/mm3) (P=0.001). By contrast, high and low monocyte groups in HFpEF patients had no significant difference in both total cardiovascular and HF-related events. Multivariate Cox hazard analysis identified a high monocyte count as an independent and significant predictor of future HF-related events in HFrEF and HFmrEF patients (hazard ratio: 3.02, 95% confidence interval: 1.20–7.59, p=0.018).

Next, by whether they had ischemic heart disease (IHD), we divided HFrEF and HFmrEF patients into two groups. Non-ischemic HF group with high monocyte counts had a significant higher risk of HF-related events compared to those with low monocyte counts (P=0.014). By contrast, there was no statistically significant difference of the occurrences of future HF-related events between in ischemic HF group with high and low monocyte counts.

Conclusion

A high monocyte count was an independent and incremental predictor of HF-related events in HFrEF and HFmrEF especially with IHD, but not in HFpEF patients.

P5480Impact of Silent Myocardial Ischemia on One Year Mortality after Successful Coronary Intervention: Data from Japanese Multicenter (KICS) Registry

Introduction

Under the awareness of appropriate use criteria, the significance of PCI for the patients with silent myocardial ischemia (SMI) decreases. On the other hand, the prognoses of SMI patients have been reported to be equivalent to those of symptomatic effort angina pectoris (EAP) patients. We aimed to clarify the prognosis of SMI after PCI and elucidate the factors influencing the mortality.

Methods

The Kumamoto Intervention Conference Study is multicenter registry enrolling consecutive patients undergoing PCI in 16 centers in Japan. Overall, 17,688 consecutive patients were enrolled during April 2008 to March 2017. To compare the clinical events between SMI and EAP, 8,278 subjects, excluding acute coronary syndrome, post successful PCI were enrolled with 1-year follow-up data.

Results

In this study, 2,071 patients were classified as SMI and 6,207 patients were EAP. Male, lower body mass index (BMI), diabetes, chronic kidney disease (CKD), smoking habits, prior myocardial infarction (MI), composite of cerebrovascular disease and composite of peripheral arterial disease were all significantly higher in the SMI group. Although nonfatal MI and stent thrombosisduring 12-monthswere comparable between the 2 groups, all-cause mortality and cardiac death during 12-months were significantly higher in the SMI group than in the EAP group (3.9% vs 1.8%, p<0.001, 1.4% vs 0.5%, p<0.001, respectively). On the other hand, Repeat Revascularization rate during 12-months was significantly lower in the SMI group than in the EAP group (15.7% vs 19.5%, p<0.001).Kaplan-Meier analysis for cardiac death showed a significant difference between the 2 groups (Figure). In a multiple logistic regression analysis, in addition to lower BMI and CKD, SMI was an independent predictor for cardiac death. Even after adjustment by propensity-score matching with predictive factors for cardiac event, SMI showed a higher cardiac death rate compared with EAP (1.4% vs 0.5%, p=0.004), and it remained as a significant predictor.

Conclusion

In this study, SMI itself was associated with higher mortality after PCI. Strict follow-up and assessment of residual ischemia should be necessary for SMI patients.

P2611The prognostic value of serum magnesium levels in patients with heart failure with preserved left ventricular ejection fraction

Background

In heart failure (HF) patients, various factors, such as hyperactivity of the renin-angiotensin system, influence of drug therapy such as loop and thiazide diuretics, undernutrition and others, can causes hypokalemia and hypomagnesemia. Although serum magnesium (Mg) levels are closely associated with the prognosis of HF patients, the clinical significance of serum Mg levels in cardiovascular outcomes of HF with preserved ejection fraction (HFpEF) patients is not fully understood.

Purpose

We examined the relationship between serum Mg and future HF-related events in patients with HFpEF.

Methods

This study was a retrospective, single-center, observational study. We enrolled 452 consecutive HFpEF patients admitted to our university hospital between January 2007 and September 2013 and followed them for 4 years or until occurrence of HF-related events. We defined lower serum Mg as <2.0 mg/dL (=0.8 mmol/L) and higher serum Mg as ≥2.0 mg/dL based on recent clinical evidences and compared their clinical characteristics and prognosis.

Results

The mean serum Mg level was 2.12 mg/dL (median, 2.1 mg/dL; interquartile range, 2.0–2.28 mg/dL). The follow-up period was 0–50 months (median, 47.3 months) and 48 HF-related events (10.6%) were recorded. The frequency of HF-related events was significantly higher in the lower serum Mg group compared with the higher serum Mg group (n=16, 17.4% vs. n=32, 8.9%; P=0.018). There were no significant differences between groups in the use of all drugs (loop diuretics, mineralcorticoid receptor antagonists, renin-angiotensin-aldosterone system inhibitors, calcium channel blockers, β-blockers, statins and Mg preparations). The lower serum Mg group (n=92) showed significantly higher prevalence of diabetes mellitus (DM), uric acid levels and B-type natriuretic peptide (BNP)levels compared with the higher serum Mg group (n=360). Kaplan-Meier curve revealed a significantly higher probability of HF-related events in the lower serum Mg group compared with the higher serum Mg group (log-rank test, P=0.012, Figure). Multivariate Cox proportional hazard analysis revealed that the lower serum Mg group had significantly and independently higher probabilities of HF-related events compared with those in the higher serum Mg group (hazard ratio: 2.37, 95% confidence intervals: 1.27–4.41, P=0.007). We reclassified the risk of a HF-related events after adding the lower serum Mg to the prognostic factors (age, previous hospitalization for HF, DM, ln-BNP); the continuous net reclassification improvement was 29.0% (p=0.041).

Conclusion

We first demonstrated that serum Mg was significantly correlated with the occurrence of future HF-related events in HFpEF patients. Lower serum Mg is able to successfully predict future HF-related events, and management of serum Mg in HFpEF patients is thus important.

Acknowledgement/Funding

None

P3392Potential of imaging-guided PCI for event suppression in Japanese acute myocardial infarction patients: J-MINUET substudy

Background

Intravascular ultrasound (IVUS) and Optical Coherence Tomography (OCT) has been widely used in clinical settings. Although favorable results of imaging-guided percutaneous coronary intervention (PCI) compared with angio-guided PCI were observed in several studies, impacts of institutional-based usage frequency, about imaging-guided PCI, have not been well elucidated.

Methods

To elucidate the impact of imaging-guided PCI and the effects of frequency of its usage, we analyzed data of the Japanese registry of acute Myocardial INfarction diagnosed by Universal dEfiniTion (J-MINUET). This was a prospective and multicenter registry consisting of 3,283 AMI patients, who were hospitalized within 48 hours of onset from July 2012 to March 2014. Clinical follow-up data was obtained for 3 years. In this sub-study, a total of 2,788 patients who underwent urgent PCI having detailed procedural information were enrolled. We analyzed the differences of utilization rates of imaging-guided PCI among the participating institutions and the impacts for the clinical events. The participating institutions were divided into 3 groups by the frequency of IVUS usage: low frequency institutions: under 50%; moderate frequency institutions: 50% to 90%; and, high frequency institutions: over 90%.

Results

In this cohort registry, patients were enrolled from 28 institutions. The utilization rate of coronary imaging varied widely depending on each institution from 15.4% to 100% (mean 85.7%±24.3, median 97.4%). When the institutions were divided into 3 groups by the frequency of intravascular imaging usage, four low frequency institutions enrolled 295 patients, five moderate frequency institutions enrolled 624 patients, and 19 high frequency institutions enrolled 1,491 patients. Although the incidence of MACE (death, MI, stroke, cardiac failure, or revascularization for unstable angina) decreased stepwise (33.2%, 23.7%, and 19.7%) (gray bar in the Figure), the event rates of the imaging-guided PCI cases among the 3 groups were comparable (21.6%, 21.9%, and 19.6%) (white bar in the Figure). On the other hand, a gradual event reduction between the 3 groups was observed in the angio-guided PCI cases (black bar in the Figure). In comparison of MACE rate between imaging-guided and angio-guided PCI, there were statistically significant differences in the low frequency and moderate frequency institutions (p=0.001 and p=0.012, respectively). In contrast, comparable event rates were observed in the high frequency institutions (p=0.441).

MACE rate by imaging usage frequency

Conclusions

In Japanese ACS patients treated with imaging-guided PCI, better suppression of clinical events during 3-year was found in the institutions with the more frequent use of intravascular imaging, mainly due to stepwise event suppression in the cases of angio-guided PCI. On the other hand, the clinical benefit of coronary imaging was obtained independently of the frequency of use and its experience.

P3764Morphological mechanisms of atrial functional mitral regurgitation in patients with atrial fibrillation

Background

Atrial functional mitral regurgitation (AFMR) occurs in patients with atrial fibrillation. However, morphological mechanisms of AFMR are poorly understood.

Purpose

The purpose of this study was to examine the morphological characteristics in patients with AFMR.

Methods

Among consecutive 795 patients undergoing initial radiofrequency catheter ablation (RFCA) at our hospital, twenty-five patients with persistent AF accompanied by AFMR (≥ moderate) before RFCA (AFMR group) were studied. Age-matched 25 patients with persistent AF without MR were defined as a control group.

Results

Left ventricular ejection fraction (LVEF) was lower and left atrium volume index was larger in the AFMR group (Table). Mitral valve annulus diameter and length of anterior mitral leaflet (AML) were similar between groups, whereas length of posterior mitral leaflet (PML) was significantly shorter in the AFMR group. Smaller tethering angle of AML (γ in the figure) and shorter tethering height were significantly associated with the occurrence of AFMR, which were different from morphology of functional mitral regurgitation in patients with dilated LV. Multiple regression analysis revealed that less tenting height (p<0.05) and LA dilatation toward the posterior (p<0.01) were significantly related to AFMR.

Echocardiographic parameters AFMR (n=25) Control (n=25) P value Age, y 69±8 66±10 NS Male, n (%) 9 (36) 20 (80) P=0.001 LVEF,% 60±9 67±6 P=0.004 LAD, mm 44±5 41±7 NS LAVI, ml/m2 56±17 41±13 P<0.001 MV diameter, mm 3.9±0.4 3.8±0.5 NS α angle, ° 34±9 35±7 NS β angle, ° 48±9 50±8 NS γ angle, ° 32±5 37±5 P=0.0005 AML length, mm 3.0±0.5 3.0±0.5 NS PML length, mm 2.1±0.1 2.4±0.1 P=0.03 Tenting height, mm 1.5±0.1 1.8±0.1 P=0.02 D, mm 0.8±0.3 0.5±0.3 P=0.001 LVEF: left ventricular ejection fraction; LAD: left atrial diameter; LAVI: left atrial volume index; AML: anterior mitral leaflet; PML: posterior mitral leaftlet.

Conclusions

AFMR occurs in patients with unique morphological features, such as less tethering height and LA dilatation toward the posterior.

P1025Clinical predictors for the improvement of left ventricular ejection fraction and prognosis after catheter ablation of atrial fibrillation in patients with systolic dysfunction

Background

Catheter ablation (CA) of atrial fibrillation (AF) improves left ventricular ejection fraction (LVEF) and clinical outcomes in patients with left ventricular systolic dysfunction (LVSD). However, predictors of the improvement of LV function and clinical outcomes by CA were poorly understood.

Purpose

We examined the efficacy of CA in AF patients with LVSD and predictive factors associated with clinical outcomes.

Method

Among consecutive 795 patients undergone initial RFCA at our hospital, we studied 51 patients with LVSD (LVEF ≤50%). Improved LVEF more then 5% at 1-year after CA was classified as “responder” to CA. We analyzed clinical variables and echocardiographic parameters before and after the CAs.

Results

In the responder group, LVEF was significantly improved 1-year after catheter ablation compared with the non-responder group. (ΔLVEF 22±12% vs. −1±4%, p<0.001). The responder group was significantly younger, had more non-paroxysmal AF, smaller LV systolic diameter and lower plasma BNP level before CA (Table). Late gadolinium enhancement (LGE)-positive rate in cardiovascular magnetic resonance imaging (CMR) before CA was higher in the non-responder group than in the responder group (100% [6/6] vs. 38% [5/13], p<0.005). After CAs of AF, event-free survival from hospitalization for heart failure was significantly higher in the responder group (Figure) with less AF recurrence (27% vs. 47%, p=0.04) than in the non-responder group.

Baseline characteristics Responder (N=35) Non-Responder (N=16) P value Age, y 62±11 69±8 p<0.01 Male, n (%) 26 (74) 13 (76) NS Non-pAF 26 (74) 4 (24) p<0.01 LAD, mm 48±7 48±8 NS LAVI, ml/m2 54±17 58±20 NS LVDd, mm 54±7 58±10 NS LVDs, mm 43±7 48±10 p=0.05 EF, % 37±8 38±8 NS BNP (pg/ml) 278±225 684±848 p<0.05

Conclusion

Younger age, absence of LV dilatation, lower plasma BNP, or absence of LGE may well predict favorable clinical outcomes after CA in patients with LVSD.

P4334Effects of Asian dust on blood pressure and blood cell counts: a cross-sectional study of health check-up data

Introduction

Asian dust (AD) is one of the health care problems because AD increases risk for mortality, respiratory, and cardiovascular disease. Previous animal studies showed that particulate matter from AD induced oxidative stress and systemic inflammation, increased blood pressure and heart rate, and decreased cardiac contraction. However, few reports show association of AD with increased blood pressure in human healthy subjects.

Purpose

The aim of this study was to investigate effects of AD on blood pressure and blood cell counts in human.

Methods

Using generalized linear models, we estimated the association between short-term exposure to AD and systolic blood pressure (SBP), diastolic blood pressure (DBP), heart rate (HR) and white blood cell (WBC) count in 296,168 participants aged 20 and older (men n=168,579, 56.9%) who underwent medical check-ups and had no anti-hypertensive agents between April 2005 and March 2015 in a health check-up center in Japan. AD days were the days on which AD events occurred, which were defined as decreased visibility (<10km) due to AD monitored by local meteorological observatory. Propensity score matching analysis was performed to reduce the effects of possible confounders such as age, sex, mean temperature, humidity. In multivariable generalized linear models, data of other air pollutant such as SO2, NO2, Ox or suspended particulate matter was used as covariate.

Results

During study period, 61 AD days were observed, and there were 4,670 participants undergoing medical check-ups on AD days. In the propensity score matched population (n=4,670, each), short-term exposure to AD was significantly associated with an increased risk of higher SBP, DBP, HR, or WBC count [β=1.303, 95% confidence interval (CI) 0.577 to 2.029 for SBP, β=0.630, 95% CI 0.122 to 1.138 for DBP, β=0.987, 95% CI 0.410 to 1.563 for HR, β=150.0, 95% CI 64.9 to 235.1 for WBC]. These significant associations were also observed in two-pollutant models. In subgroup analysis according to age, AD exposure had greater impact on SBP, DBP, and HR in younger people (20 to 40 years old), but WBC count in middle-high age (51 years and older).

GLM analysis according to age category

Conclusions

The present study showed that short-term exposure to AD was associated with higher SBP, DBP, HR and WBC count. Short-term exposure to AD may exacerbate sympathetic nervous system for the young and immune system for the elderly.

P1954Prognostic value of the CHADS2 score for adverse cardiovascular events in acute myocardial infarction patients without atrial fibrillation: J-MINUET Substudy

Background

The CHADS2score has mainly been used to predict the likelihood of cerebrovascular accidents in patients with atrial fibrillation. However, increasing attention is being paid to this scoring system for risk stratification of patients with coronary artery disease. We investigated the value of the CHADS2 score in predicting cardiovascular events in Japanese acute myocardial infarction (AMI) patients without atrial fibrillation.

Methods

To elucidate the prognostic value of CHADS2score in AMI patients, we analysed data of the Japanese registry of acute Myocardial INfarction diagnosed by Universal dEfiniTion (J-MINUET). This was a prospective and multicenter registry consisting of 3,283 AMI patients, who were hospitalized within 48-hours of onset from July 2012 to March 2014. We calculated the CHADS2 scores for 3,044 patients without clinical evidence of atrial fibrillation. The presence of heart failure was substituted by Killip classification>2 on admission. Clinical follow-up data was obtained for 3 years. In addition to the in-hospital mortality,we evaluated cardiovascular events, defined as all cause deathor non-fatal MI during 3-year follow up periods.

Results

In this study, enrolled patients were classified into low- (point 0–1), intermediate- (point 2–3), and high-score (point 4–6) groups by calculating CHADS2 score. Overall patients with low, intermediate and high score were divided into 1,395, 1,393 and 256 patients, respectively. In-hospital mortality among low, intermediate, and high score groups were 2.8%, 7.4% and 14.8%, respectively (P<0.001). The incidence of cardiovascular eventsamong low, intermediate, and high score groups were 7.8%, 16.3%, 29.3%, respectively (P<0.001). Kaplan-Meier analysis showed a significant difference between the groups (Figure). The event rates were significantly higher in both high score and intermediate score group than in low score group (P<0.001). Multivariate Cox hazard analysis identified CHADS2 score (per 1 point) as an independent predictor of cardiovascular events in addition to chronic kidney disease and lower body mass index. (hazard ratio, 1.344; 95% CI, 1.239–1.459; P<0.001). Among the factors constituting CHADS2 score, heart failure and age were identified as independent predictors for in-hospital mortality. With respect to the cardiovascular event during 3 years, heart failure, age, and previous stroke were revealed as significant independent predictors.

Conclusion

This large cohort study indicated that the CHADS2 score is useful for the prediction of in-hospital mortality and the cardiovascular events during 3-year follow up in Japanese AMI patients without atrial fibrillation.