Effect of α-tubulin acetylation on the doublet microtubule structure

Acetylation of α-tubulin at the lysine 40 residue (αK40) by αTAT1/MEC-17 acetyltransferase modulates microtubule properties and occurs in most eukaryotic cells. Previous literatures suggest that acetylated microtubules are more stable and damage resistant. αK40 acetylation is the only known microtubule luminal post-translational modification site. The luminal location suggests that the modification tunes the lateral interaction of protofilaments inside the microtubule. In this study, we examined the effect of tubulin acetylation on the doublet microtubule (DMT) in the cilia of Tetrahymena thermophila using a combination of cryo-electron microscopy, molecular dynamics, and mass spectrometry. We found that αK40 acetylation exerts a small-scale effect on the DMT structure and stability by influencing the lateral rotational angle. In addition, comparative mass spectrometry revealed a link between αK40 acetylation and phosphorylation in cilia.

The ATPase asymmetry: Novel computational insight into coupling diverse FO motors with tripartite F1

ATP synthase, a crucial enzyme for cellular bioenergetics, operates via the coordinated coupling of an FO motor, which presents variable symmetry, and a tripartite F1 motor. Despite extensive research, the understanding of their coupling dynamics, especially with non-10-fold symmetrical FO motors, remains incomplete. This study investigates the coupling patterns between eightfold and ninefold FO motors and the constant threefold F1 motor using coarse-grained molecular dynamics simulations. We unveil that in the case of a ninefold FO motor, a 3-3-3 motion is most likely to occur, whereas a 3-3-2 motion predominates with an eightfold FO motor. Furthermore, our findings propose a revised model for the coupling method, elucidating that the pathways' energy usage is primarily influenced by F1 rotation and conformational changes hindered by the b-subunits. Our results present a crucial step toward comprehending the energy landscape and mechanisms governing ATP synthase operation.

Native doublet microtubules from Tetrahymena thermophila reveal the importance of outer junction proteins

Cilia are ubiquitous eukaryotic organelles responsible for cellular motility and sensory functions. The ciliary axoneme is a microtubule-based cytoskeleton consisting of two central singlets and nine outer doublet microtubules. Cryo-electron microscopy-based studies have revealed a complex network inside the lumen of both tubules composed of microtubule-inner proteins (MIPs). However, the functions of most MIPs remain unknown. Here, we present single-particle cryo-EM-based analyses of the Tetrahymena thermophila native doublet microtubule and identify 42 MIPs. These data shed light on the evolutionarily conserved and diversified roles of MIPs. In addition, we identified MIPs potentially responsible for the assembly and stability of the doublet outer junction. Knockout of the evolutionarily conserved outer junction component CFAP77 moderately diminishes Tetrahymena swimming speed and beat frequency, indicating the important role of CFAP77 and outer junction stability in cilia beating generation and/or regulation.

Regulatory mechanisms of the dynein-2 motility by post-translational modification revealed by MD simulation

Intraflagellar transport for ciliary assembly and maintenance is driven by dynein and kinesins specific to the cilia. It has been shown that anterograde and retrograde transports run on different regions of the doublet microtubule, i.e., separate train tracks. However, little is known about the regulatory mechanism of this selective process. Since the doublet microtubule is known to display specific post-translational modifications of tubulins, i.e., "tubulin code", for molecular motor regulations, we investigated the motility of ciliary specific dynein-2 under different post-translational modification by coarse-grained molecular dynamics. Our setup allows us to simulate the landing behaviors of dynein-2 on un-modified, detyrosinated, poly-glutamylated and poly-glycylated microtubules in silico. Our study revealed that poly-glutamylation can play an inhibitory effect on dynein-2 motility. Our result indicates that poly-glutamylation of the B-tubule of the doublet microtubule can be used as an efficient means to target retrograde intraflagellar transport onto the A-tubule.

Multicenter registry of the Watchman left atrial appendage closure device for patients with atrial fibrillation in Japan: The TERMINATOR registry

Funding Acknowledgements

Type of funding sources: Private grant(s) and/or Sponsorship. Main funding source(s): Boston Scientific Japan

Background

Transcatheter left atrial appendage closure (LAAC) provides an alternative to oral anticoagulation for thromboembolic risk reduction in patients with nonvalvular atrial fibrillation (AF). A meta-analysis of previous two randomized trials reported improved rates of hemorrhagic stroke, cardiovascular/unexplained death, and nonprocedural bleeding compared to warfarin (1). Recently, the next-generation LAAC device, the Watchman FLX system, became available, and showed a low incidence of adverse events and a high incidence of anatomic closure (2). This transcatheter stroke prevention has already been approved in Asian countries. However, there is little data of LAAC in Asian population.

Purpose

This study sought to assess efficacy and safety of LAAC for patients with nonvalvular AF in Asia.

Methods

The TERMINATOR (Transcatheter Modification of Left Atrial Appendage by Obliteration with Device) registry is a multicenter nonrandomized study in Japan. This enrolled patients who underwent LAAC in 23 Japanese institutions. The LAAC was indicated for patients with nonvalvular atrial fibrillation in whom oral anticoagulation is required, but who have a risk of bleeding (history of BARC type 3 bleeding or HAS-BLED score ≥3 points). Baseline patient and procedural characteristics and clinical outcomes were evaluated.

Results

A total of 729 patients were enrolled between September 2019 and November 2021. The mean age was 74.9±8.8 years and the mean CHA2DS2-VASc score was 4.7±1.5. The Watchman generation 2.5 and FLX system were used in 469 (64.3%) and 260 patients (35.7%), respectively. Procedural success was achieved in 722 patients (99.0%). In-hospital adverse events were as follows; 6 tamponades (0.8%), 3 pericardial effusion (0.4%), 2 device embolization (0.3%), no stroke (0%), and no death (0%). During follow-up, device-related thrombus and all-cause death were reported in 16 (2.2%) and 23 patients (3.2%), respectively.

Conclusions

LAAC with the Watchman system provides compatible efficacy and safety outcomes in Asian population.

FO-F1 coupling and symmetry mismatch in ATP synthase resolved in every FO rotation step

F_OF₁ ATP synthase, a ubiquitous enzyme that synthesizes most ATP in living cells, is composed of two rotary motors, a membrane-embedded proton-driven F_O motor, and a catalytic F₁ motor. These motors share both central and peripheral stalks. Although both F_O and F₁ have pseudo-symmetric structures, their symmetries do not match. How symmetry mismatch is solved remains elusive because of the missing intermediate structures of the rotational steps. Here, for the case of Bacillus PS3 ATP synthases with 3- and 10-fold symmetries in F₁ and F_O, respectively, we uncovered the mechanical couplings between F_O and F₁ at every 36º-rotation step via molecular dynamics simulations and comparative studies of cryo-electron microscopy (EM) structures from three species. We found that the mismatch could be solved using several elements: (1) the F₁ head partially rotates relative to the F_O a-subunit via elastic distortion of the b-subunits, (2) the rotor is twisted, and (3) comparisons of cryo-EM structures further suggest that the c-ring rotary angles can deviate from the symmetric ones. In addition, the F₁ motor may have non-canonical structures, relieving stronger frustration. Thus, we provide new insights for solving the symmetry mismatch problem.

Increased levels of a pro-inflammatory IgG receptor in the midbrain of people with schizophrenia

BACKGROUND

There is growing evidence that neuroinflammation may contribute to schizophrenia neuropathology. Elevated pro-inflammatory cytokines are evident in the midbrain from schizophrenia subjects, findings that are driven by a subgroup of patients, characterised as a "high inflammation" biotype. Cytokines trigger the release of antibodies, of which immunoglobulin G (IgG) is the most common. The level and function of IgG is regulated by its transporter (FcGRT) and by pro-inflammatory IgG receptors (including FcGR3A) in balance with the anti-inflammatory IgG receptor FcGR2B. Testing whether abnormalities in IgG activity contribute to the neuroinflammatory abnormalities schizophrenia patients, particularly those with elevated cytokines, may help identify novel treatment targets.

METHODS

Post-mortem midbrain tissue from healthy controls and schizophrenia cases (n = 58 total) was used to determine the localisation and abundance of IgG and IgG transporters and receptors in the midbrain of healthy controls and schizophrenia patients. Protein levels of IgG and FcGRT were quantified using western blot, and gene transcript levels of FcGRT, FcGR3A and FcGR2B were assessed using qPCR. The distribution of IgG in the midbrain was assessed using immunohistochemistry and immunofluorescence. Results were compared between diagnostic (schizophrenia vs control) and inflammatory (high vs low inflammation) groups.

RESULTS

We found that IgG and FcGRT protein abundance (relative to β-actin) was unchanged in people with schizophrenia compared with controls irrespective of inflammatory subtype. In contrast, FcGRT and FcGR3A mRNA levels were elevated in the midbrain from "high inflammation" schizophrenia cases (FcGRT; p = 0.02, FcGR3A; p < 0.0001) in comparison to low-inflammation patients and healthy controls, while FcGR2B mRNA levels were unchanged. IgG immunoreactivity was evident in the midbrain, and approximately 24% of all individuals (control subjects and schizophrenia cases) showed diffusion of IgG from blood vessels into the brain. However, the intensity and distribution of IgG was comparable across schizophrenia cases and control subjects.

CONCLUSION

These findings suggest that an increase in the pro-inflammatory Fcγ receptor FcGR3A, rather than an overall increase in IgG levels, contribute to midbrain neuroinflammation in schizophrenia patients. However, more precise information about IgG-Fcγ receptor interactions is needed to determine their potential role in schizophrenia neuropathology.

Rotational Mechanism of FO Motor in the F-Type ATP Synthase Driven by the Proton Motive Force

In FOF1 ATP synthase, driven by the proton motive force across the membrane, the FO motor rotates the central rotor and induces conformational changes in the F1 motor, resulting in ATP synthesis. Recently, many near-atomic resolution structural models have been obtained using cryo-electron microscopy. Despite high resolution, however, static information alone cannot elucidate how and where the protons pass through the FO and how proton passage is coupled to FO rotation. Here, we review theoretical and computational studies based on FO structure models. All-atom molecular dynamics (MD) simulations elucidated changes in the protonation/deprotonation of glutamate—the protein-carrier residue—during rotation and revealed the protonation states that form the “water wire” required for long-range proton hopping. Coarse-grained MD simulations unveiled a free energy surface based on the protonation state and rotational angle of the rotor. Hybrid Monte Carlo and MD simulations showed how proton transfer is coupled to rotation.

Cooperation among c-subunits of FoF1-ATP synthase in rotation-coupled proton translocation

In F_oF₁-ATP synthase, proton translocation through F_o drives rotation of the c-subunit oligomeric ring relative to the a-subunit. Recent studies suggest that in each step of the rotation, key glutamic acid residues in different c-subunits contribute to proton release to and proton uptake from the a-subunit. However, no studies have demonstrated cooperativity among c-subunits toward F_oF₁-ATP synthase activity. Here, we addressed this using Bacillus PS3 ATP synthase harboring a c-ring with various combinations of wild-type and cE56D, enabled by genetically fused single-chain c-ring. ATP synthesis and proton pump activities were decreased by a single cE56D mutation and further decreased by double cE56D mutations. Moreover, activity further decreased as the two mutation sites were separated, indicating cooperation among c-subunits. Similar results were obtained for proton transfer-coupled molecular simulations. The simulations revealed that prolonged proton uptake in mutated c-subunits is shared between two c-subunits, explaining the cooperation observed in biochemical assays.

Cells need to be able to store and transfer energy to fuel their various activities. To do this, they produce a small molecule called ATP to carry the energy, which is then released when the ATP is broken down. An enzyme found in plants, animals and bacteria, called F_oF₁ ATP synthase, can both create and use ATP. When it does this, protons, or positive hydrogen ions, are transported across cellular boundaries called membranes.

The region of the enzyme that is responsible for pumping the protons contains different parts known as the c-ring and the a-subunit. The movement of protons drives the c-ring to rotate relative to the a-subunit, which leads to producing ATP. Previous research using simulations and the protein structures found there are two or three neighbouring amino acids in the c-ring that face the a-subunit, suggesting that these amino acids act together to drive the rotation.

To test this hypothesis, Mitome et al. mutated these amino acids to examine the effect on the enzyme’s ability to produce ATP. A single mutation reduced the production of ATP, which decreased even further with mutations in two of the amino acids. The extent of this decrease depended on the distance between the two mutations in the c-ring. Simulations of these changes also found similar results. This indicates there is coordination between different parts of the c-ring to increase the rate of ATP production.

This study offers new insights into the molecular processes controlling ATP synthesis and confirms previous theoretical research. This will interest specialists in bioenergetics because it addresses a fundamental biological question with broad impact.

Heterogeneous dissociation process of truncated RNAs by oligomerized Vasa helicase

RNA helicases are enzymes that generally unwind double-stranded RNA using ATP hydrolysis energy, mainly involved in RNA metabolism, transcription, translation, and mRNA splicing. While the helicase core is crucial for RNA unwinding activity, N- and C-terminal extensions of specific helicases may contain an intrinsically disordered region for electrostatic interaction, resulting in the formation of droplets in the cytoplasm. However, how the disordered region of the RNA helicase contributes to RNA unwinding and dissociation remains unclear. Here, we focused on Bombyx mori Vasa, which unwinds truncated target transposon RNAs from the piRNA-induced silencing complex piRISC. In this study, we used single-molecule techniques to visualise how Vasa dynamically interacts with piRISC and investigate how Vasa oligomerization is involved in the process of piRNA amplification, named the ping-pong pathway. We found that Vasa’s oligomerization is required during these processes in vitro and in vivo, and that Vasa triggers the dissociation of truncated RNA in heterogeneous pathways. Our single-molecule results suggest that oligomerized Vasa guides the timing of the process regulating overall dissociation efficiency.

Kinoshita et al. use single molecule imaging to show that the N-terminal extension of BmVasa, a germ-specific DEAD box RNA helicase, is necessary for protein oligomerization and the dissociation of target RNA from the Siwi-piRISC complex. The authors conclude that oligomerized Vasa guides the timing of the regulation of overall dissociation efficiency.

Impact of Magnetic Field Configuration on Heat Transport in Stellarators and Heliotrons

We assess the magnetic field configuration in modern fusion devices by comparing experiments with the same heating power, between a stellarator and a heliotron. The key role of turbulence is evident in the optimized stellarator, while neoclassical processes largely determine the transport in the heliotron device. Gyrokinetic simulations elucidate the underlying mechanisms promoting stronger ion scale turbulence in the stellarator. Similar plasma performances in these experiments suggests that neoclassical and turbulent transport should both be optimized in next step reactor designs.

Remodeling and activation mechanisms of outer arm dyneins revealed by cryo-EM

Cilia are thin microtubule-based protrusions of eukaryotic cells. The swimming of ciliated protists and sperm cells is propelled by the beating of cilia. Cilia propagate the flow of mucus in the trachea and protect the human body from viral infections. The main force generators of ciliary beating are the outer dynein arms (ODAs) which attach to the doublet microtubules. The bending of cilia is driven by the ODAs' conformational changes caused by ATP hydrolysis. Here, we report the native ODA complex structure attaching to the doublet microtubule by cryo-electron microscopy. The structure reveals how the ODA complex is attached to the doublet microtubule via the docking complex in its native state. Combined with coarse-grained molecular dynamic simulations, we present a model of how the attachment of the ODA to the doublet microtubule induces remodeling and activation of the ODA complex.

Prognostic grade for resecting hepatocellular carcinoma: multicentre retrospective study

BACKGROUND

Surgical treatment for hepatocellular carcinoma (HCC) is advancing, but a robust prediction model for survival after resection is not available. The aim of this study was to propose a prognostic grading system for resection of HCC.

METHODS

This was a retrospective, multicentre study of patients who underwent first resection of HCC with curative intent between 2000 and 2007. Patients were divided randomly by a cross-validation method into training and validation sets. Prognostic factors were identified using a Cox proportional hazards model. The predictive model was built by decision-tree analysis to define the resection grades, and subsequently validated.

RESULTS

A total of 16 931 patients from 795 hospitals were included. In the training set (8465 patients), four surgical grades were classified based on prognosis: grade A1 (1236 patients, 14.6 per cent; single tumour 3 cm or smaller and anatomical R0 resection); grade A2 (3614, 42.7 per cent; single tumour larger than 3 cm, or non-anatomical R0 resection); grade B (2277, 26.9 per cent; multiple tumours, or vascular invasion, and R0 resection); and grade C (1338, 15.8 per cent; multiple tumours with vascular invasion and R0 resection, or R1 resection). Five-year survival rates were 73.9 per cent (hazard ratio (HR) 1.00), 64.7 per cent (HR 1.51, 95 per cent c.i. 1.29 to 1.78), 50.6 per cent (HR 2.53, 2.15 to 2.98), and 34.8 per cent (HR 4.60, 3.90 to 5.42) for grades A1, A2, B, and C respectively. In the validation set (8466 patients), the grades had equivalent reproducibility for both overall and recurrence-free survival (all P < 0.001).

CONCLUSION

This grade is used to predict prognosis of patients undergoing resection of HCC.

W-band millimeter-wave back-scattering system for high wavenumber turbulence measurements in LHD

A 90 GHz W-band millimeter-wave back-scattering system is designed and installed for measuring electron scale turbulence (k_⊥ρ_s ∼ 40). A metal lens relay antenna is used for in-vessel beam focusing, and a beam diameter of less than 40 mm is achieved in the plasma core region. This antenna can be steered at an angle of 159° ± 6°, which almost covers the plasma radius. The estimated size of the scattering volume is ∼105 mm at the edge and 135 mm at the core, respectively. A 60 m corrugated waveguide is used to achieve a low transmission loss of ∼8 dB. A heterodyne detection system for millimeter-wave circuits with probing power modulation can distinguish the scattered signal from background noise.

Laparoscopic and open liver resection for hepatocellular carcinoma with Child-Pugh B cirrhosis: multicentre propensity score-matched study

BACKGROUND

Laparoscopic liver resection for hepatocellular carcinoma (HCC) in Child-Pugh A cirrhosis has been demonstrated as beneficial. However, the role of laparoscopy in Child-Pugh B cirrhosis is undetermined. The aim of this retrospective cohort study was to compare open and laparoscopic resection for HCC with Child-Pugh B cirrhosis.

METHODS

Data on liver resections were gathered from 17 centres. A 1 : 1 propensity score matching was performed according to 17 predefined variables.

RESULTS

Of 382 available liver resections, 100 laparoscopic and 100 open resections were matched and analysed. The 90-day postoperative mortality rate was similar in open and laparoscopic groups (4.0 versus 2.0 per cent respectively; P = 0.687). Laparoscopy was associated with lower blood loss (median 110 ml versus 400 ml in the open group; P = 0.004), less morbidity (38.0 versus 51.0 per cent respectively; P = 0.041) and fewer major complications (7.0 versus 21.0 per cent; P = 0.010), and ascites was lower on postoperative days 1, 3 and 5. For laparoscopic resections, patients with portal hypertension developed more complications than those without (26 versus 12 per cent respectively; P = 0.002), and patients with a Child-Pugh B9 score had higher morbidity rates than those with B8 and B7 (7 of 8, 10 of 16 and 21 of 76 respectively; P < 0.001). Median hospital stay was 7.5 (range 2-243) days for laparoscopic liver resection and 18 (3-104) days for the open approach (P = 0.058). The 5-year overall survival rate was 47 per cent for open and 65 per cent for laparoscopic resection (P = 0.142). The 5-year disease-free survival rate was 32 and 37 per cent respectively (P = 0.742).

CONCLUSION

Patients without preoperative portal hypertension and Child-Pugh B7 cirrhosis may benefit most from laparoscopic liver surgery.

Q-band high-performance notch filters at 56 and 77 GHz notches for versatile fusion plasma diagnostics

A six-pole Q-band waveguide filter with a notch frequency above the Q-band has been developed for plasma diagnostics. The previous paper [Nishiura et al., J. Instrum. 10, C12014 (2015)] reported that the notch frequency exists within the standard band. In this study, the newly required notch filter extends the function, which prevents a thorny wave from being mixed into an instrument beyond the standard bandwidth of the waveguide. The mode control technique for cavities realizes a deep and sharp filter shape for Q-band notch filters with 56 and 77 GHz notches, respectively. The former filter has an attenuation more than 50 dB at 56.05 GHz and a bandwidth of 1.1 GHz at -3 dB. The latter filter has an attenuation more than 55 dB at 76.95 GHz and a bandwidth of 1.6 GHz at -3 dB. The electron cyclotron emission imaging and the electron cyclotron emission (ECE) diagnostics for the Q-band implemented a pair of the fabricated filters and demonstrated the ECE measurement successfully in the intense stray radiation from a 56 GHz gyrotron.

Early restenosis and late catch-up phenomenon after newer biodegradable- and durable-polymer drug-eluting stent implantations

Background

It is yet to be known whether mechanisms underlying restenosis in newer-generation durable-polymer (DP) and biodegradable-polymer (BP) drug-eluting stents (DES) are different.

Purpose

This study aims to assess the incidences and predictors of early restenosis and late catch-up phenomenon after newer-generation durable-polymer (DP) and biodegradable-polymer (BP) DES.

Methods

Between 2010 and 2017, 13858 lesions in 6350 patients were treated with DES (4393 BP-DES, 9465 DP-DES). The early-term (within 1 year) and late-term (from 1 to 2 years) follow-up angiographies were scheduled. Late catch-up phenomenon was defined as in-stent restenosis (ISR) in lesions that evaded ISR within 1 year after stent implantation. ISR was defined as angiographic restenosis of more than 50%.

Results

The mean patient age was 71 years, and 76.7% were male. Early-term angiographies were performed in 10955 lesions (79.0%). Of those without early-term ISR, late-term angiographies were performed in 7771 lesions (56.1%). The incidences of mid-term restenosis and late catch-up phenomenon were 6.6% and 3.9%, respectively.

In the multivariate regression analyses, history of diabetes, hemodialysis and previous PCI were independent predictors of both early restenosis and late catch-up phenomenon. Also, some lesion characteristics such as chronic total occlusion, right coronary artery ostial lesion, small vessel (defined as reference diameter &lt;2.5mm), long lesion (defined as lesion length &gt;30mm) and treatment of ISR lesion were independent predictors of both early restenosis and late catch-up phenomenon.

Bifurcation lesion and heavily calcified lesion treated with rotablator were independent risk of early restenosis. Bypass graft lesion was an independent predictor of late catch-up phenomenon.

Early restenosis was observed less frequently in DP-DES than in BP-DES (6.3% versus 7.4%, P=0.012). On the contrary, late catch-up phenomenon was observed more frequently in DP-DES than in BP-DES (4.3% versus 2.9%, P=0.026).

Conclusions

Some lesion characteristics were independent predictors of early restenosis and late catch-up phenomenon after newer-generation DES implantation. The deployment of BP-DES resulted in more early restenosis and less late catch-up phenomenon compared to that of DP-DES.

Early Restenosis and Late Catch-Up

Funding Acknowledgement

Type of funding source: None

Clinical features and prognosis of acute myocardial infarction due to coronary artery embolism

Background

Coronary artery embolism (CE) is one of the important causes of acute coronary syndrome (ACS). The feature of CE is that angiographic evidence of coronary artery embolism and thrombosis without atherosclerotic components. However, the prevalence of CE remains unknown because of the diffifulty to diagnose in the acute settings. A recent retrospective analysis suggested that up to 3% of ACS cases may result from CE.

Purpose

The aim of this study was to elucidate the prevalence, clinical features and long-term outcomes including all-cause and cardiac death.

Methods

We analysed the consecutive 2695 patients with first AMI performed coronary intervention between January 2004 and July 2017. CE was diagnosed by clinical histories and angiographic findings. We retrospectively evaluated the clinical and lesion characteristics and outcomes including all-cause and cardiac death.

Results

The prevalence of CE was 2.0% (n=55; CE group and n=2640; non-CE group), including 8 (15%) patients with multivessel CE. The CE group had higher average age (70.8±14.9 vs. 68.4±12.6, p&lt;0.01), prevalence of female (54% vs. 27%, p&lt;0.01), lower prevalence of smoking (34% vs. 62%, p&lt;0.01). The common causes with CE were atrial fibrillation (47%), and malignant tumor (9%), and cardiomyopathy (5%), and patent foramen ovale (4%). Only 20% of patients with CE were treated with anti-coagulant therapy. The rate of distal infarction site (defined as #4, #8, #14–15) was significantly higher in CE group than non-CE group (54.0% vs. 4.9%, p&lt;0.01). During median follow-up of 53.6 [32.6–77.3] months, CE and thromboembolism recurred in 5 patients (CE: 1 patient, stroke 4 patients). The 4-year incidence of all-cause death was significantly higher in the CE group, but cardiac death was not significantly different between the groups (28.8% vs. 14.8%, p=0.03; 12.8% vs. 5.1%, p=0.11).

Conclusion

Compared with non-CE group, the prevalence of distal infarction site was significantly higher in the CE group, and the incidence of cardiac death is not significantly different.

Funding Acknowledgement

Type of funding source: None

Risk stratification based on academic research consortium high bleeding risk criteria for long-term bleeding event after everolimus-eluting stent implantation

Background

Recently, the Academic Research Consortium for High Bleeding Risk (ARC-HBR) criteria has been suggested as the standard definition of HBR.

Purpose

We aimed to investigate the risk stratification based on ARC-HBR Criteria for long-term bleeding event after everolimus-eluting stent implantation

Methods

The study population comprised 1193 patients treated with EES without in-hospital event between 2010 and 2011. Individual ARC-HBR criteria was retrospectively assessed. Major bleeding were defined as the occurrence of a Bleeding Academic Research Consortium type 3 or 5 bleeding event. The mean follow-up period was 2996±433 days.

Results

There were 656 patients (55.0%) in HBR-groups. Cumulative incidence of major bleeding was significantly higher in HBR-group (8.1% vs 3.4% at 4 year, and 16.2% vs 5.7% at 8 year, P&lt;0.001). Cumulative rate of major bleeding tend to be higher as the number of ARC-HBR criteria increased (≥2 Majors: 24.3%, 1 Major: 17.0%, ≥2 Minors:11.7%, and Non-HBR: 5.7%, P&lt;0.001).

Conclusion

ARC-HBR criteria successfully stratified the long-term bleeding risk after drug-eluting stent implantation in real-world practice.

Funding Acknowledgement

Type of funding source: None

FRI0102 SERUM TNFΑ LEVELS AT 24 HOURS AFTER FIRST ADMINISTRATION OF CERTOLIZUMAB PEGOL PREDICT EFFECTIVENESS AT WEEK 12 IN PATIENTS WITH RHEUMATOID ARTHRITIS FROM TSUBAME STUDY (UMIN ID:0002381)

Background:

To increase the remission rate of rheumatoid arthritis (RA), it is necessary to determine the efficacy of the tumor necrosis factor (TNF) inhibitor as early as possible. Moreover, the response to certolizumab pegol (CZP) at 12 weeks has been reported to predict its long-term efficacy.

Objectives:

As part of a prospective single-center observational study (TSUBAME study), we prospectively enrolled patients to be treated with CZP in our institution to evaluate its effectiveness and safety starting at 24 hours after the first dose in clinical settings, while recording blood CZP concentrations and biomarkers over time to examine their correlation with clinical effects.

Methods:

One hundred patients with RA and inadequate response to MTX who received CZP were enrolled in the TSUBAME study. The changes in serum TNFα, IL-6, and CZP levels at 24 hours after first administration of CZP were measured, and the correlation between serum biomarkers and clinical response was determined.

Results:

At 24 hours after CZP initiation, significant improvement was observed in the disease activity (baseline and 24 h: 5.4 ± 1.3, 5.0 ± 1.3, respectively, p < 0.01), which was maintained until week 12. (baseline and 12 w: 5.4 ± 1.3, 3.3 ± 1.4, respectively, p < 0.01). Serum TNFα and IL-6 levels significantly decreased at 24 hours after first administration of CZP compared to baseline. No correlation was found between TNFα and IL-6 levels at baseline and the clinical response. According to univariate analysis, low serum TNFα and IL-6 levels and high CZP levels at 24 hours were associated with DAS28 (ESR) remission at 12 weeks. According to multivariate analysis, low serum TNFα levels at 24 hours were significantly associated with DAS28 (ESR) remission at 12 weeks (OR 0.05, 95%CI 0.01, 0.75, p = 0.03). Based on these findings, an ROC curve was created using remission according to the DAS28 (ESR) at week 12 as a dependent variable and TNFα concentration at 24 hours as an independent variable, resulting in a cut-off value of 0.76 pg/ml. From this result, the TNFα concentration at 24 hours was divided into 2 groups according to this cut-off, and the rates of remission according to the DAS28 (ESR) at week 12 were compared. In the group with TNFα concentration at 24 hours below the cut-off value, the rate of remission according to the DAS28 (ESR) at week 12 was significantly higher than in the group with TNFα concentration at 24 hours above the cut-off value (below the cut-off: above the cut-off = 56.3%: 21.6%, p < 0.001). Between the group that achieved remission according to the DAS28(ESR) and the group that did not achieve remission at week 12, there was almost no difference in the distribution of TNFα concentrations at baseline; however, the distribution of TNFα concentrations at 24 hours was lower in the group that achieved remission.

Conclusion:

CZP was effective where serum TNFα was strongly neutralized within 24 hours. These results suggest that low serum TNFα levels at 24 hours after first administration of CZP may predict the effectiveness of CZP. To increase the remission rate in RA, it is necessary to determine the effectiveness of the molecular targeted drugs used at an early point, in addition to how rapid the onset of action is. CZP is extremely fast-acting, and its effectiveness can be predicted as early as 24 hours after the first dose, suggesting that it may be possible to determine the effectiveness early.

Acknowledgments:

The authors thank Ms. M. Hirahara for providing excellent technical assistance.

Disclosure of Interests:

Yusuke Miyazaki Grant/research support from: Astellas Pharma Inc and UCB S.A., Kazuhisa Nakano: None declared, Shingo Nakayamada Grant/research support from: Mitsubishi-Tanabe, Takeda, Novartis and MSD, Speakers bureau: Bristol-Myers, Sanofi, Abbvie, Eisai, Eli Lilly, Chugai, Asahi-kasei and Pfizer, Satoshi Kubo: None declared, Shigeru Iwata: None declared, Kentaro Hanami: None declared, Shunsuke Fukuyo: None declared, Ippei Miyagawa: None declared, Ayako Yamaguchi: None declared, Akio Kawabe: None declared, SAITO KAZUYOSHI: None declared, Yoshiya Tanaka Grant/research support from: Asahi-kasei, Astellas, Mitsubishi-Tanabe, Chugai, Takeda, Sanofi, Bristol-Myers, UCB, Daiichi-Sankyo, Eisai, Pfizer, and Ono, Consultant of: Abbvie, Astellas, Bristol-Myers Squibb, Eli Lilly, Pfizer, Speakers bureau: Daiichi-Sankyo, Astellas, Chugai, Eli Lilly, Pfizer, AbbVie, YL Biologics, Bristol-Myers, Takeda, Mitsubishi-Tanabe, Novartis, Eisai, Janssen, Sanofi, UCB, and Teijin

How Cytoplasmic Dynein Couples ATP Hydrolysis Cycle to Diverse Stepping Motions: Kinetic Modeling

Cytoplasmic dynein is a two-headed molecular motor that moves to the minus end of a microtubule by ATP hydrolysis free energy. By employing its two heads (motor domains), cytoplasmic dynein exhibits various bipedal stepping motions: inchworm and hand-over-hand motions, as well as nonalternating steps of one head. However, the molecular basis to achieve such diverse stepping manners remains unclear because of the lack of an experimental method to observe stepping and the ATPase reaction of dynein simultaneously. Here, we propose a kinetic model for bipedal motions of cytoplasmic dynein and perform Gillespie Monte Carlo simulations that qualitatively reproduce most experimental data obtained to date. The model represents the status of each motor domain as five states according to conformation and nucleotide- and microtubule-binding conditions of the domain. In addition, the relative positions of the two domains were approximated by three discrete states. Accompanied by ATP hydrolysis cycles, the model dynein stochastically and processively moved forward in multiple steps via diverse pathways, including inchworm and hand-over-hand motions, similarly to experimental data. The model reproduced key experimental motility-related properties, including velocity and run length, as functions of the ATP concentration and external force, therefore providing a plausible explanation of how dynein achieves various stepping manners with explicit characterization of nucleotide states. Our model highlights the uniqueness of dynein in the coupling of ATPase with its movement during both inchworm and hand-over-hand stepping.

The inner junction complex of the cilia is an interaction hub that involves tubulin post-translational modifications

Microtubules are cytoskeletal structures involved in stability, transport and organization in the cell. The building blocks, the α- and β-tubulin heterodimers, form protofilaments that associate laterally into the hollow microtubule. Microtubule also exists as highly stable doublet microtubules in the cilia where stability is needed for ciliary beating and function. The doublet microtubule maintains its stability through interactions at its inner and outer junctions where its A- and B-tubules meet. Here, using cryo-electron microscopy, bioinformatics and mass spectrometry of the doublets of Chlamydomonas reinhardtii and Tetrahymena thermophila, we identified two new inner junction proteins, FAP276 and FAP106, and an inner junction-associated protein, FAP126, thus presenting the complete answer to the inner junction identity and localization. Our structural study of the doublets shows that the inner junction serves as an interaction hub that involves tubulin post-translational modifications. These interactions contribute to the stability of the doublet and hence, normal ciliary motility.

P2693Late catch-up phenomenon and late-term target lesion revascularization of two-stenting for coronary bifurcation lesions between first and second generation drug-eluting stents

Background

The second generation drug-eluting stent (G2-DES) has been reported as superior to the first generation drug-eluting stent (G1-DES) in mid-term outcomes. However, the late-term outcomes between G1-DES and G2-DES in two-stenting for coronary bifurcation lesions are not well studied.

Purpose

To evaluate the late catch-up phenomenon and late-term target lesion revascularization (TLR) of two-stenting for coronary bifurcation lesions between G1-DES and G2-DES.

Methods

This study included 1133 lesions in 1089 patients undergoing drug eluting stent implantation with two stenting from 2004 to 2016. These consisted of 496 G1-DES implanted lesions and 637 G2-DES implanted lesions. Late-term follow-up angiography was performed without in-stent restenosis (ISR) and TLR at mid-term follow-up in 582 lesions (242 G1-DES lesions and 340 G2-DES lesions). ISR was defined as more than 50% restenosis. Late catch-up phenomenon was defined as ISR without ISR within 1 year following index stent implantation. Late-term TLR was defined as from 1 to 5 year TLR. Bifurcation lesions were defined as the main branch ranging from the proximal stem to the distal main branch with boundaries defined by 5 mm proximal and distal to the stent-implanted area, and the side branch ranging from the bifurcation carina to the distal side branch with boundaries defined by the carina and 5 mm distal to the stent-implanted area.

Results

The median follow-up duration was 5.1 years (the first and third quarters, 3.2 and 7.1 years). The late-catch up phenomenon rate significantly differed between the G1-DES and G2-DES groups (16.9% vs 8.4%, p=0.001). A significant difference in late catch-up between the same two groups was also observed in bifurcation lesions of the main branch (5.0% vs 0.6%, p=0.001) and side branch (10.3% vs 5.6%, p=0.033), respectively. The 5-year cumulative rates also differed between the two groups in TLR (8.2% vs 3.7% log-rank p=0.001), and late-term TLR (7.0% vs 3.6% log-rank p=0.001).

Conclusion

Two-stenting using G2-DES, compared with G1-DES, significantly reduced late-term restenosis and TLR. The restenosis rate in bifurcation area may be associated with differences between two groups in late-term outcome.

P5614The association between tissue morphology assessed with optical coherence tomography and mid and late-term results after percutaneous coronary intervention for in-stent restenosis lesions

Background

It was reported that tissue morphology of in-stent restenosis (ISR) lesions assessed with optical coherence tomography (OCT) had an effect on midterm results including ISR and target lesion revascularization (TLR) rates after percutaneous coronary intervention (PCI). However, little was known about the association between tissue morphology assessed with OCT and late-term results.

Methods

We performed PCI treated with paclitaxel coated balloon (PCB) or drug-eluting stent (DES) for 452 ISR lesions (260 lesions with fibrous plaque and 192 lesions with lipid-laden plaque) using OCT between May 2008 and July 2016. Six- to eight-month (midterm) angiographic follow-up was performed on 422 of the 452 ISR lesions (follow-up rate: 93.4%). Furthermore, eighteen- to twenty-month (late-term) angiographic follow-up was performed on 337 of the 361 ISR lesions (follow-up rate: 93.4%) which were free from midterm TLR. We examined the association between tissue morphology, midterm-results and late-term results including ISR and TLR rates. Fibrous plaque was defined as homogeneous, signal-rich regions with low attenuation. Lipid-laden plaque was defined as diffuse border, signal poor regions with high attenuation.

Results

The patients were 353 men and 69 women, and the mean age was 68.8±9.6 years. PCI were performed with PCB in 285 lesions (PCB group) and DES in 137 lesions (DES group). The figure shows the angiographic midterm results of the 422 lesions and late-term results of the 337 lesions with respect to each tissue morphology and each PCI device. There was no difference in ISR and TLR rates of lesions with both fibrous and lipid-laden plaque at midterm between the two groups. ISR and TLR rates of lesions with lipid-laden plaque at late-term were significantly higher in the PCB group than in the DES group, while there was no difference in ISR and TLR rates of lesions with fibrous plaque at late-term between two groups.

Figure 1

Conclusion

Tissue morphology of ISR lesions might have an impact on outcomes after PCI. Morphological assessment of ISR tissue using OCT might suggest favorable types of PCI for ISR lesions.

Efficacy and safety of anti-CD20 antibody rituximab for patients with refractory systemic lupus erythematosus

Objective

We examined the efficacy and safety of rituximab in patients with refractory systemic lupus erythematosus (SLE).

Methods

The study enrolled 63 SLE patients who were treated with rituximab between 2002 and 2015. The participants underwent a battery of tests before treatment and at one year. Treatment ranged from two to four times at 500 or 1000 mg.

Results

Baseline characteristics were males:females = 6:57, age 33.9 years, and disease duration 87.2 months. The primary endpoint: The rate of major clinical response (MCR) was 60% while the partial clinical response (PCR) was 25%. Thirty of 36 (83%) patients with lupus nephritis (WHO II: 2, III: 5, IV: 22, V: 4, IV+V: 2, not assessed: 1) and 22 of 24 patients (92%) with neuropsychiatric SLE, who could be followed at one year, showed changes from BILAG A or B score to C or D score at one year. Multivariate analysis identified high anti-dsDNA antibody and shorter disease duration as significant determinants of MCR at one year. Repeat examination was conducted at five years. Primary failure was recorded in 8.8% and secondary failure in 32.4% (time to relapse: 24.4 months). Rituximab was well tolerated although 65 adverse events, mostly infections, were recorded within one year.

Conclusion

Rituximab is potentially efficacious for the treatment of patients with refractory SLE.

A case of refractory lupus nephritis complicated by psoriasis vulgaris that was controlled with secukinumab

It has been reported that T helper 17 cells are involved in the pathogenesis of systemic lupus erythematosus, but there is no report on interleukin-17-targeted therapy. We report a case of a 62-year-old female who presented with psoriasis vulgaris and refractory lupus nephritis. Because her conditions were resistant to conventional treatment, and flow cytometry confirmed the proliferation of activated T helper 17 cells in peripheral blood, and examination of a renal biopsy tissue sample confirmed infiltration of numerous interleukin-17-positive lymphocytes to the renal interstitium, administration of the anti-interleukin-17A antibody secukinumab was initiated. After starting secukinumab the clinical and biological features were improved.