Evaluation of novel indices of walking performance taking oxygen desaturation into account during six-minute walk test in cardiovascular disease patients

In pulmonary disease patients since oxygen desaturation during 6-min walk test (6MWT) affects walk distance (6MWD), some novel indices such as desaturation/distance ratio [DDR, oxygen desaturation area (DAO2)/6MWD] and distance-saturation product [DSP, 6MWD × minimum peripheral oxygen saturation (SpO2)] are evaluated. However, there has been no study examining these indices that consider exercise-induced desaturation (EID) in patients with cardiovascular disease. In 94 cardiovascular disease patients without pulmonary complications, 6MWT and echocardiography were performed at the entry of cardiac rehabilitation. SpO2 was measured during 6MWT using a continuously monitorable pulse oximeter, and DSP and DDR were calculated using minimum SpO2 and DAO2 [sum of (100-SpO2) per second during 6MWT], respectively. EID was defined as SpO2 decrease of ≥ 4% or minimum SpO2 of < 90% during 6MWT. DSP was slightly lower and DDR was markedly higher in patients with EID than in those without. When examining correlations of DSP and DDR with their components, DSP was correlated with 6MWD much closely than minimum SpO2, while DDR was correlated as closely with DAO2 as 6MWD. Furthermore, DAO2, but not minimum SpO2, had a direct correlation with 6MWD. As for associations with cardiac function, DSP was correlated with several cardiac parameters, but DDR was not correlated with any of these parameters. Our findings suggest that oxygen desaturation during 6MWT affects walking distance in cardiovascular disease patients even without pulmonary complications and that DDR is more appropriate than DSP as an index of walking performance that takes EID into consideration, independently of cardiac function.

Development and validation of a novel craniofacial statistical shape model for the virtual reconstruction of bilateral maxillary defects

Bilateral maxillary defects are a challenge for fibula free flap reconstruction (FFFR) surgery due to limitations in virtual surgical planning (VSP) workflows. While meshes of unilateral defects can be mirrored to virtually reconstruct missing anatomy, Brown class c and d defects lack a contralateral reference and associated anatomical landmarks. This often results in poor placement of osteotomized fibula segments. This study was performed to improve the VSP workflow for FFFR using statistical shape modeling (SSM) - a form of unsupervised machine learning - to virtually reconstruct premorbid anatomy in an automated, reproducible, and patient-specific manner. A training set of 112 computed tomography scans was sourced from an imaging database by stratified random sampling. The craniofacial skeletons were segmented, aligned, and processed via principal component analysis. Reconstruction performance was validated on a set of 45 unseen skulls containing various digitally generated defects (Brown class IIa-d). Validation metrics demonstrated promising accuracy: mean 95th percentile Hausdorff distance of 5.47 ± 2.39 mm, mean volumetric Dice coefficient of 48.8 ± 14.5%, compactness of 7.28 × 105 mm2, specificity of 1.18 mm, and generality of 8.12 × 10-6 mm. SSM-guided VSP will allow surgeons to create patient-centric treatment plans, increasing FFFR accuracy, reducing complications, and improving postoperative outcomes.

Dynamic action of an intrinsically disordered protein in DNA compaction that induces mycobacterial dormancy

Mycobacteria are the major human pathogens with the capacity to become dormant persisters. Mycobacterial DNA-binding protein 1 (MDP1), an abundant histone-like protein in dormant mycobacteria, induces dormancy phenotypes, e.g. chromosome compaction and growth suppression. For these functions, the polycationic intrinsically disordered region (IDR) is essential. However, the disordered property of IDR stands in the way of clarifying the molecular mechanism. Here we clarified the molecular and structural mechanism of DNA compaction by MDP1. Using high-speed atomic force microscopy, we observed that monomeric MDP1 bundles two adjacent DNA duplexes side-by-side via IDR. Combined with coarse-grained molecular dynamics simulation, we revealed the novel dynamic DNA cross-linking model of MDP1 in which a stretched IDR cross-links two DNA duplexes like double-sided tape. IDR is able to hijack HU function, resulting in the induction of strong mycobacterial growth arrest. This IDR-mediated reversible DNA cross-linking is a reasonable model for MDP1 suppression of the genomic function in the resuscitable non-replicating dormant mycobacteria.

Atomistic mechanism of structural and volume relaxation below glass transition temperature in a soda-lime silicate glass revealed by Raman spectroscopy and its DFT calculations

To elucidate the atomistic origin of volume relaxation in soda-lime silicate glass annealed below the glass transition temperature (Tg), the experimental and calculated Raman spectra were compared. By decomposing the calculated Raman spectra into specific groups of atoms, the Raman peaks at 800, 950, 1050, 1100, and 1150 cm-1 were attributed to oxygen and silicon in Si-O-Si, non-bridging oxygen in the Q2 unit, bridging oxygen in low-angle Si-O-Si, non-bridging oxygen in the Q4 unit, and bridging oxygen in high-angle Si-O-Si, respectively. Based on these attributions, we found that by decreasing the fictive temperature by annealing below Tg - 70 K, a homogenization reaction Q2 + Q4 → 2Q3 and an increase in average Si-O-Si angle occurred simultaneously. By molecular dynamics simulation, we clarified how the experimentally demonstrated increase in average Si-O-Si angle contributes to volume shrinkage; increasing Si-O-Si angles can expand the space inside the rings, and Na can be inserted into the ring center.

Genome-wide mapping and cryo-EM structural analyses of the overlapping tri-nucleosome composed of hexasome-hexasome-octasome moieties

The nucleosome is a fundamental unit of chromatin in which about 150 base pairs of DNA are wrapped around a histone octamer. The overlapping di-nucleosome has been proposed as a product of chromatin remodeling around the transcription start site, and previously found as a chromatin unit, in which about 250 base pairs of DNA continuously bind to the histone core composed of a hexamer and an octamer. In the present study, our genome-wide analysis of human cells suggests another higher nucleosome stacking structure, the overlapping tri-nucleosome, which wraps about 300-350 base-pairs of DNA in the region downstream of certain transcription start sites of actively transcribed genes. We determine the cryo-electron microscopy (cryo-EM) structure of the overlapping tri-nucleosome, in which three subnucleosome moieties, hexasome, hexasome, and octasome, are associated by short connecting DNA segments. Small angle X-ray scattering and coarse-grained molecular dynamics simulation analyses reveal that the cryo-EM structure of the overlapping tri-nucleosome may reflect its structure in solution. Our findings suggest that nucleosome stacking structures composed of hexasome and octasome moieties may be formed by nucleosome remodeling factors around transcription start sites for gene regulation.

Ultra-high temperature Soret effect in a silicate melt: SiO2 migration to cold side

The Soret effect, temperature gradient driven diffusion, in silicate melts has been investigated intensively in the earth sciences from the 1980s. The SiO2 component is generally concentrated in the hotter region of silicate melts under a temperature gradient. Here, we report that at ultra-high temperatures above ∼3000 K, SiO2 becomes concentrated in the colder region of the silicate melts under a temperature gradient. The interior of an aluminosilicate glass [63.3SiO2-16.3Al2O3-20.4CaO (mol. %)] was irradiated with a 250 kHz femtosecond laser pulse for local heating. SiO2 migrated to the colder region during irradiation with an 800 pulse (3.2 ms irradiation). The temperature analysis indicated that migration to the colder region occurred above 3060 K. In the non-equilibrium molecular dynamics (NEMD) simulation, SiO2 migrated to the colder region under a temperature gradient, which had an average temperature of 4000 K; this result supports the experimental result. On the other hand, SiO2 exhibited a tendency to migrate to the hotter region at 2400 K in both the NEMD and experimental study. The molar volume calculated by molecular dynamics simulation without a temperature gradient indicates two bends at 1650 and 3250 K under 500 MPa. Therefore, the discontinuous (first order) transition with coexistence of two phases of different composition could be related to the migration of SiO2 to colder region. However, the detailed mechanism has not been elucidated.

The E/e' ratio on echocardiography as an independent predictor of the improvement of left ventricular contraction in patients with heart failure with reduced ejection fraction

OBJECTIVE

Clinical feature of heart failure with improved ejection fraction (HFimpEF) remains to be fully elucidated. The present study investigated the association of clinical and echocardiographic parameters with the subsequent improvement of left ventricular ejection fraction (LVEF) in heart failure with reduced ejection fraction (HFrEF).

METHODS

From outpatients with a history of hospitalized for heart failure, 128 subjects diagnosed as HFrEF (LVEF <40%) on heart failure hospitalization were enrolled and longitudinally surveyed. During follow-up periods more than 1 year, 58 and 42 patients were identified as HFimpEF (improved LVEF to ≥40% and its increase of ≥10 points) and persistent HFrEF, respectively.

RESULTS

There was no difference in age or sex between the two groups with HFimpEF and persistent HFrEF. The rate of ischemic heart disease was lower and that of tachyarrhythmia was higher in the HFimpEF group than in the persistent HFrEF group. At baseline (i.e., on heart failure hospitalization), LVEF did not differ between the two groups, but left ventricular systolic and diastolic diameters were already smaller and the ratio of early diastolic transmitral velocity to early diastolic tissue velocity (E/e') was lower in the HFimpEF group. A multiple logistic regression analysis revealed that lower baseline E/e' was a significant determinant of HFimpEF, independently of confounding factors such as ischemic heart disease, tachyarrhythmia, and baseline left ventricular dimension.

CONCLUSION

Our findings indicate that the lower ratio of E/e' in the acute phase of heart failure onset is an independent predictor of the subsequent improvement of LVEF in HFrEF patients.

White epidermoid cyst transformation after stereotactic radiosurgery: illustrative case

BACKGROUND

White epidermoid cysts (WECs) are a rare type of epidermoid cyst with atypical radiological features. The epidemiological aspects and mechanisms of their onset remain unknown. Herein, the authors report a unique case of WEC transformation from a typical epidermoid cyst after stereotactic radiosurgery (SRS), confirmed by radiological and pathological findings.

OBSERVATIONS

The case involved a 78-year-old man with a history of 2 surgeries for a left cerebellopontine angle typical epidermoid cyst 23 years earlier and SRS using the CyberKnife for recurrent trigeminal neuralgia (TN) 14 years earlier. The tumor with high intensity on T1-weighted imaging, low intensity on T2-weighted imaging, without restriction on diffusion-weighted imaging had gradually enlarged after SRS. Therefore, a salvage surgery was performed via a left suboccipital craniotomy, and the intraoperative findings showed a cyst with a brown, viscous liquid component, consistent with those of WECs. Histopathologically, keratin calcification and hemorrhage were identified, leading to a diagnosis of WEC. The postoperative course was uneventful, and the TN resolved. No tumor recurrence was recorded at 2 years postoperatively.

LESSONS

To the best of the authors' knowledge, this is the first world case of WEC transformation from a typical epidermoid cyst after SRS, confirmed by radiological and pathological findings. Radiation effects could have been involved in this transformation.

RNF213 p.Arg4810Lys Wild Type is Associated with De Novo Hemorrhage in Asymptomatic Hemispheres with Moyamoya Disease

Clinical implications of RNF213 genetic variants, other than p.Arg4810Lys, in moyamoya disease (MMD), remain unclear. This study aimed to investigate the association of RNF213 variants with clinical phenotypes in MMD. This retrospective cohort study collected data regarding the clinical characteristics of 139 patients with MMD and evaluated the angioarchitectures of 253 hemispheres using digital subtraction angiography at diagnosis. All RNF213 exons were sequenced, and the associations of clinical characteristics and angiographical findings with p.Arg4810Lys, p.Ala4399Thr, and other rare variants (RVs) were examined. Among 139 patients, 100 (71.9%) had p.Arg4810Lys heterozygote (GA) and 39 (28.1%) had the wild type (GG). Fourteen RVs were identified and detetcted in 15/139 (10.8%) patients, and p.Ala4399Thr was detected in 17/139 (12.2%) patients. Hemispheres with GG and p.Ala4399Thr presented with significantly less ischemic events and more hemorrhagic events at diagnosis (p = 0.001 and p = 0.028, respectively). In asymptomatic hemispheres, those with GG were more susceptible to de novo hemorrhage than those with GA (adjusted hazard ratio [aHR] 5.36) with an increased risk when accompanied by p.Ala4399Thr or RVs (aHR 15.22 and 16.60, respectively). Within the choroidal anastomosis-positive hemispheres, GG exhibited a higher incidence of de novo hemorrhage than GA (p = 0.004). The GG of p. Arg4810Lys was a risk factor for de novo hemorrhage in asymptomatic MMD hemispheres. This risk increased with certain other variants and is observed in choroidal anastomosis-positive hemispheres. A comprehensive evaluation of RNF213 variants and angioarchitectures is essential for predicting the phenotype of asymptomatic hemispheres in MMD.

Visible-Light-Driven C-H Imidation of Arenes and Heteroarenes by a Phosphonium Ylide Organophotoredox Catalyst: Application to C-H Functionalization of Alkenes

Phosphonium ylide catalysis through an oxidative quenching cycle has been developed for visible-light-driven C-H imidation of arenes and heteroarenes. The present protocol could be applied not only to trihalomethylative lactonization reactions involving trifluoromethyl, trichloromethyl, and tribromomethyl radicals but also to the first example of an organophotoredox-catalyzed imidative lactonization reaction involving a nitrogen-centered electrophilic radical species.

Formation of NV centers in diamond by a femtosecond laser single pulse

The NV centers in a diamond were successfully created by the femtosecond laser single pulse. We also investigated the effect on the diamond lattice induced by the different laser pulse widths from both experimental and theoretical perspectives. Interestingly, in spite of the high thermal conductivity of a diamond, we found that there is a suitable pulse repetition rate of several tens kHz for the formation of NV center ensembles by the femtosecond laser pulse irradiation.

Efficient Multiple Domain Ligation for Proteins Using Asparaginyl Endopeptidase by Selection of Appropriate Ligation Sites Based on Steric Hindrance

Three domain fragments of a multi-domain protein, ER-60, were ligated in two short linker regions using asparaginyl endopeptidase not involving denaturation. To identify appropriate ligation sites, by selecting several potential ligation sites with fewer mutations around two short linker regions, their ligation efficiencies and the functions of the ligated ER-60s were examined experimentally. To evaluate the dependence of ligation efficiencies on the ligation sites computationally, steric hinderances around the sites for the ligation were calculated through molecular dynamics simulations. Utilizing the steric hindrance, a site-dependent ligation potential index was introduced as reproducing the experimental ligation efficiency. Referring to this index, the reconstruction of ER-60 was succeeded by the ligation of the three domains for the first time. In addition, the new ligation potential index well-worked for application to other domain ligations. Therefore, the index may serve as a more time-effective tool for multi-site ligations.

Thermal chemical vapor deposition of layered carbon nitride films under hydrogen gas atmosphere

We prepared layered carbon nitride (g-C3N4) films via thermal chemical vapor deposition under an atmosphere of nitrogen (N2) and hydrogen (H2). Crystalline films ordered along the layered stacking direction were...

Biohybrid robots: recent progress, challenges, and perspectives

The past ten years have seen the rapid expansion of the field of biohybrid robotics. By combining engineered, synthetic components with living biological materials, new robotics solutions have been developed that harness the adaptability of living muscles, the sensitivity of living sensory cells, and even the computational abilities of living neurons. Biohybrid robotics has taken the popular and scientific media by storm with advances in the field, moving biohybrid robotics out of science fiction and into real science and engineering. So how did we get here, and where should the field of biohybrid robotics go next? In this perspective, we first provide the historical context of crucial subareas of biohybrid robotics by reviewing the past 10+ years of advances in microorganism-bots and sperm-bots, cyborgs, and tissue-based robots. We then present critical challenges facing the field and provide our perspectives on the vital future steps toward creating autonomous living machines.

Nuclear accumulation of MLKL induces necroptosis in cardiomyocytes: potential implication in Doxorubicin-induced cardiotoxicity

Background

The treatment with doxorubicin, a powerful chemotherapeutic agent, has been shown to be associated with an increased risk of lethal heart failure. Although various types of cell death pathway such as apoptosis and ferroptosis have been shown to be involved in the development of doxorubicin-induced cardiotoxicity, DIC, the involvement of necroptosis, a novel programmed necrosis induced by translocation of activated mixed lineage kinase domain-like protein, MLKL, to plasma membrane, remains unclear.

Purpose

The aim of this study was to determine whether necroptosis is involved in the development of DIC.

Methods and results

DIC was induced in C57BL/6J mice by intraperitoneal injection of doxorubicin at a dose of 10 mg/kg 3 times for a week. Eight days after the commencement of injection, echocardiographic analyses showed that left ventricular ejection fraction assessed by echocardiography was significantly lower in the doxorubicin-treated mice than in the vehicle-treated mice (44.0±13.7 vs. 70.5±3.7%), indicating the development of DIC. Immunoblot analysis showed that MLKL protein level was higher by 1.6 fold in the doxorubicin-treated mice than in the vehicle-treated mice. Interestingly, immunohistochemical analysis showed that signals of phospho-Ser345-MLKL, an activated form of MLKL, was found in the nuclei in addition to cytosol and intercalated discs of cardiomyocytes in the doxorubicin-treated mice. To get novel insight into significance of nuclear MLKL accumulation, a leucine-rich nuclear export signal (NES) spanning amino acids 280–284 of rat MLKL was identified by site-directed mutation analyses, and H9c2 cells, cultured rat cardiomyoblasts, were transfected with expression constructs for nucleus-directed MLKL (FLAG-mtNES-MLKL) or its wild type (FLAG-WT-MLKL). Percentage of FLAG-positive cells stained with Zombie Red, a fluorescent dye that is non-permeant to live cells, was higher in FLAG-mtNES-MLKL-transfected cells than in FLAG-WT-MLKL-transfected cells (80.0±3.5% vs. 6.3±1.3%, p&lt;0.05), whereas percentage of cells immunostained with cleaved caspase-3 to FLAG-positive cells was similar in the two groups. The effect of the MLKL mutant on necroptosis was attenuated by treatment with GppNHp, an inhibitor of Ran-mediated nuclear protein import.

Conclusion

Nuclear accumulation of MLKL induces necroptosis in cardiomyocytes, which may contribute to progression of DIC.

Funding Acknowledgement

Type of funding sources: None.

Involvement of growth differentiation factor 15 in paradoxical relationship between body mass index and mortality in patients with suspected or known coronary artery disease; The ANOX Study

Background

Obesity is a well-established risk factor for type 2 diabetes mellitus, hypertension and dyslipidemia, leading to coronary artery disease (CAD). Nevertheless, body mass index (BMI) is inversely associated with cardiovascular (CV) mortality in patients with cardiac disorders, termed “obesity paradox”. However, the underlying mechanism remains unclear.

Purpose

To clarify important factors involved in the pathogenesis of obesity paradox.

Methods

Using data from a multicenter, prospective cohort of 2,418 patients with suspected or known CAD enrolled in the ANOX study, we assessed the relationship between BMI at baseline and the incidence of CV death over 3 years, and investigated the involvement of several endocrine factors which were previously reported to have some roles in obesity and heart diseases, such as adiponectin, N-terminal pro-brain natriuretic peptide (NT-proBNP) and growth differentiation factor 15 (GDF-15), in the relationship between BMI and CV death.

Results

In Kaplan-Meier analyses, the lower quartiles of BMI and the higher quartiles of adiponectin levels were paradoxically associated with the higher cumulative incidence of CV death. To clarify the important factors involved in the paradoxical association between BMI or adiponectin and mortality, we first investigated independent determinants for BMI and adiponectin levels respectively, using multiple stepwise regression analyses among many clinical factors, and then narrow down the prognostic factors commonly associated with BMI and adiponectin, which were age, hemoglobin and NT-proBNP. Interestingly, circulating levels of GDF15 were significantly correlated with NT-proBNP levels, and the presence of anemia raised the gradient of the correlation line in a scatter plot (without anemia, r=0.139, p&lt;0.0001; with anemia, r=0.228, p&lt;0.0001). Moreover, the highest GDF15 quartile showed significantly lower BMI and higher adiponectin levels compared to the lower quartiles (p&lt;0.001 and p&lt;0.001, respectively, by Student t-test). In Cox proportional hazard models, hazard ratios (HRs) of BMI (per 1-unit increase) were 0.90 (95% confidence interval [CI], 0.85–0.96) for CV death. Additional adjustment for hemoglobin, NT-proBNP, adiponectin or GDF15 diminished the statistical significance (HR, 0.92 [95% CI, 0.87–0.99], 0.95 [0.89–1.01], 0.92 [0.87–0.99], or 0.93 [0.87–0.99], respectively).

Conclusions

The lower BMI and the higher adiponectin levels were paradoxically associated with the higher incidence of CV death in patients with CAD. This paradox may be mediated by cardiac endocrine factors induced by cardiac stresses, including GDF-15 in addition to natriuretic peptides.

Funding Acknowledgement

Type of funding sources: Public Institution(s). Main funding source(s): The ANOX study is supported by a Grant-in-Aid for Clinical Research from the National Hospital Organization.

Vascular endothelial factor C and D in patients with heart failure with preserved, mildly reduced, and reduced ejection fraction: the PREHOSP-CHF study

Background

The lymphatic system has been suggested to play an important role in cardiovascular diseases including heart failure (HF). Vascular endothelial growth factor C (VEGF-C) and D (VEGF-D) are key regulators of lymphangiogenesis, and we recently reported the association of low VEGF-C with the risk of all-cause death and high VEGF-D with the risk of HF hospitalization in patients with HF.

Purpose

To investigate the association of VEGF-C and VEGF-D with prognosis in patients with HF with preserved ejection fraction (EF) (HFpEF: EF≥50%), mildly reduced EF (HFmrEF: EF, 40–49%), and reduced EF (HFrEF: EF&lt;40%).

Methods

The PREHOSP-CHF study is a multicenter prospective cohort study to determine the predictive value of angiogenesis-related biomarkers in HF. A total of 1,024 patients (mean age 75.5±12.6 years; 58.7% male) admitted to acute decompensated HF were included in the analyses. Serum levels of VEGF-C and VEGF-D, as well as N-terminal pro B-type natriuretic peptide (NT-proBNP), high sensitivity cardiac troponin-I (hs-cTnI), high sensitivity C reactive protein, were measured at the time of discharge. Patients were followed-up over two years.

Results

The numbers of HFpEF, HFmrEF, and HFrEF were 429 (41.9%), 186 (18.2%), and 409 (39.9%), respectively. HFpEF patients were older, more likely to be female, and had more hypertension, atrial fibrillation, and anemia, but less coronary artery disease. NT-proBNP and hs-cTnI levels increased with decreasing EF. VEGF-C levels decreased with increasing EF (median [interquartile range]: HFpEF, 4508 [3318–5919] pg/ml; HFmrEF, 4719 [3663–6203] pg/ml; HFrEF, 5023 [3804–6382] pg/ml), whereas VEGF-D levels were comparable among the three EF groups (HFpEF, 404.6 [293.1–560.3] pg/ml; HFmrEF, 386.0 [298.5–556.3] pg/ml; HFrEF, 414.2 [296.1–557.3] pg/ml). In multivariate stepwise logistic regression analyses, anemia and high NT-proBNP were independently associated with low VEGF-C levels, and high NT-proBNP was independently associated with high VEGF-D levels, across all the EF groups. During the follow-up, incidences of all-cause death and HF hospitalizations were similar among the three EF groups (log-rank P=0.6 for all-cause death, and log-rank P=0.3 for HF hospitalization). On multivariate Cox proportional hazard analyses including established risk factors and cardiovascular biomarkers, VEGF-C levels tended to be inversely associated with the incidence of all-cause death in patients with HFpEF and HFrEF (Figure). On the contrary, VEGF-D levels were significantly and positively associated with the incidence of HF hospitalization in patients with HFpEF, and tended to be positively associated with it in patients with HFmrEF and HFrEF (Figure).

Conclusions

Low VEGF-C was associated with the risk of all-cause death in patients with HFpEF and HFrEF, while high VEGF-D was associated with the risk of HF hospitalization especially in HFpEF.

Funding Acknowledgement

Type of funding sources: Public Institution(s). Main funding source(s): Grant-in-Aid for Clinical Research from the National Hospital Organization

Associations of soluble fms-like tyrosine kinase-1 with cardiovascular events and stroke in patients with atrial fibrillation and suspected or known coronary artery disease: the EXCEED-J study

Background

Atrial fibrillation (AF) increases the risk of stroke. Soluble fms-like tyrosine kinase-1 (sFlt-1), a vascular endothelial growth factor (VEGF) antagonist, has been suggested as a marker of endothelial dysfunction, which are associated with both AF and coronary artery disease (CAD). Recently, we demonstrated that sFlt-1 is independently associated with major adverse cardiovascular (CV) events (MACE) in patients with suspected or known CAD. However, the prognostic utility of sFlt-1 in patients with AF remains unknown.

Methods

Using data from a multicenter, prospective cohort of 3255 patients with suspected or known CAD, we investigated whether AF modifies the prognostic utility of sFlt-1. Heparin-free serum levels of sFlt-1, N-terminal pro-brain natriuretic peptide, high-sensitivity cardiac troponin-I, high-sensitivity C-reactive protein, cystatin C, neutrophil gelatinase-associated lipocalin, VEGF, and placental growth factor were measured in 324 patients with AF and 2931 patients without AF. The primary outcome was MACE defined as a composite of CV death, nonfatal myocardial infarction, and nonfatal stroke. The secondary outcomes were all-cause death, CV death, stroke, heart failure (HF) hospitalization, and coronary/peripheral artery revascularization. The biomarkers were natural log-transformed for use as continuous variables.

Results

After adjustment for potential clinical confounders including anticoagulant drug use, sFlt-1 was significantly associated with MACE (hazard ratio for 1 standard deviation increase [HR], 1.55; 95% confidence interval [CI], 1.14–2.08), CV death (HR, 1.68; 95% CI, 1.10–2.48), and stroke (HR, 1.89; 95% CI, 1.16–3.10), but not with all-cause death (HR, 1.32; 95% CI, 0.99–1.73), HF hospitalization (HR, 0.97; 95% CI, 0.73–1.25), or revascularization (HR, 0.99; 95% CI, 0.74–1.28) in patients with AF, whereas sFlt-1 was significantly associated with MACE (HR, 1.19; 95% CI, 1.02–1.37), all-cause death (HR, 1.19; 95% CI, 1.05–1.34), CV death (HR, 1.26; 95% CI, 1.03–1.48), and HF hospitalization (HR, 1.26; 95% CI, 1.11–1.42), but not with stroke (HR, 1.06; 95% CI, 0.81–1.33) or revascularization (HR, 1.01; 95% CI, 0.95–1.07) in patients without AF. Among other biomarkers, only VEGF was significantly associated with MACE (HR, 1.55; 95% CI, 1.02–2.44), and no biomarkers were significantly associated with CV death or stroke in patients with AF. sFlt-1 added incremental prognostic information for MACE (P=0.005 for net reclassification improvement [NRI], P=0.026 for integrated discrimination improvement [IDI]) and stroke (P=0.034 for NRI, P=0.018 for IDI), but not for CV death (P=0.021 for NRI, P=0.134 for IDI), to the model with potential clinical confounders in patients with AF.

Conclusions

sFlt-1 independently predicted MACE and stroke in patients with AF and suspected or known CAD. sFlt-1 may serve as a novel prognostic biomarker to stratify the risk of MACE and stroke in patients with AF.

Funding Acknowledgement

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Health Labour Sciences Research Grant (2013-2014), AMED (2015-2017, Grant Number JP17ek0210008)

Serum amyloid A-low-density-lipoprotein complex and mortality in patients with suspected or known coronary artery disease: the ANOX study

Background

Serum amyloid A-low-density-lipoprotein (SAA-LDL) is a complex formed from the oxidative interaction between SAA and LDLs. A relatively small-scale study has shown that circulating SAA-LDL levels may serve as a prognostic marker in patients with stable coronary artery disease (CAD). However, the prognostic value of SAA-LDL should be confirmed in a larger-scale cohort study.

Methods

Using data from a multicenter, prospective cohort of 2416 patients with suspected or known CAD enrolled in the ANOX (Development of Novel Biomarkers Related to Angiogenesis or Oxidative Stress to Predict Cardiovascular Events) study, we assessed the prognostic value of serum levels of SAA-LDL. The primary outcome was all-cause death. The secondary outcomes were cardiovascular death and major adverse cardiovascular events (MACE) defined as a composite of cardiovascular death, nonfatal myocardial infarction, and nonfatal stroke. Patients were followed up over 3 years.

Results

Stepwise regression analysis including baseline data on potential clinical confounders (i.e., age, sex, body mass index, hypertension, dyslipidemia, diabetes, current smoking, estimated glomerular filtration rate, the Gensini score, previous myocardial infarction, previous stroke, previous heart failure hospitalization, atrial fibrillation, malignancies, anemia, antihypertensive drug use, statin use, and aspirin use) and established cardiovascular biomarkers (i.e., N-terminal pro-brain natriuretic peptide, high-sensitivity cardiac troponin I [hs-cTnI], and high-sensitivity C-reactive protein [hs-CRP]) revealed that independent determinants of SAA-LDL levels were female sex, dyslipidemia, the Gensini score, absence of statin use, hs-cTnI, and hs-CRP. After adjusting for potential clinical confounders and established cardiovascular biomarkers, the highest quartile of SAA-LDL levels (vs. the lowest quartile) was significantly associated with the incidence of all-cause death (hazard ratio [HR], 1.51; 95% confidence interval [CI], 1.02–2.26), but not with that of cardiovascular death (HR, 1.11; 95% CI, 0.59–2.10) or MACE (HR, 1.57; 95% CI, 0.97–2.57). Stratified analyses revealed that this association was pronounced in patients with low hs-cTnI (&lt;75th percentile) (HR, 1.85; 95% CI, 1.06–3.30) and in patients with low hs-CRP levels (≤1.0 mg/L) (HR, 2.30; 95% CI, 1.17–4.79).

Conclusions

Elevated SAA-LDL levels were independently associated with the risk of all-cause death in patients with suspected or known CAD. The SAA-LDL level appears to serve as a prognostic biomarker for risk stratification in relatively low-risk patients with low hs-cTnI (&lt;75th percentile) or low hs-CRP (≤1.0 mg/L).

Funding Acknowledgement

Type of funding sources: Public Institution(s). Main funding source(s): The ANOX study is supported by a Grant-in-Aid for Clinical Research from the National Hospital Organization.

WNK1/HSN2 mediates neurite outgrowth and differentiation via a OSR1/GSK3β-LHX8 pathway

With no lysine kinase 1 (WNK1) phosphorylates and activates STE20/SPS1-related proline-alanine-rich protein kinase (SPAK) and oxidative stress responsive kinase 1 (OSR1) to regulate ion homeostasis in the kidney. Mutations in WNK1 result in dysregulation of the WNK1-SPAK/OSR1 pathway and cause pseudohypoaldosteronism type II (PHAII), a form of hypertension. WNK1 is also involved in the autosomal recessive neuropathy, hereditary sensory and autonomic neuropathy type II (HSANII). Mutations in a neural-specific splice variant of WNK1 (HSN2) cause HSANII. However, the mechanisms underlying HSN2 regulation in neurons and effects of HSN2 mutants remain unclear. Here, we found that HSN2 regulated neurite outgrowth through OSR1 activation and glycogen synthase kinase 3β (GSK3β). Moreover, HSN2-OSR1 and HSN2-GSK3β signalling induced expression of LIM homeobox 8 (Lhx8), which is a key regulator of cholinergic neural function. The HSN2-OSR1/GSK3β-LHX8 pathway is therefore important for neurite outgrowth. Consistently, HSN2 mutants reported in HSANII patients suppressed SPAK and OSR1 activation and LHX8 induction. Interestingly, HSN2 mutants also suppressed neurite outgrowth by preventing interaction of between wild-type HSN2 and GSK3β. These results indicate that HSN2 mutants cause dysregulation of neurite outgrowth via GSK3β in the HSN2 and/or WNK1 pathways.

Extracting time series matching a small-angle X-ray scattering profile from trajectories of molecular dynamics simulations

Solving structural ensembles of flexible biomolecules is a challenging research area. Here, we propose a method to obtain possible structural ensembles of a biomolecule based on small-angle X-ray scattering (SAXS) and molecular dynamics simulations. Our idea is to clip a time series that matches a SAXS profile from a simulation trajectory. To examine its practicability, we applied our idea to a multi-domain protein ER-60 and successfully extracted time series longer than 1 micro second from trajectories of coarse-grained molecular dynamics simulations. In the extracted time series, the domain conformation was distributed continuously and smoothly in a conformational space. Preferred domain conformations were also observed. Diversity among scattering curves calculated from each ER-60 structure was interpreted to reflect an open-close motion of the protein. Although our approach did not provide a unique solution for the structural ensemble of the biomolecule, each extracted time series can be an element of the real behavior of ER-60. Considering its low computational cost, our approach will play a key role to identify biomolecular dynamics by integrating SAXS, simulations, and other experiments.

Genome-Wide Association Study of Intracranial Artery Stenosis Followed by Phenome-Wide Association Study

The genetic background of intracranial artery stenosis (ICAS), a major cause of ischemic stroke, remains elusive. We performed the world's first genome-wide association study (GWAS) of ICAS using DNA samples from Japanese subjects, to identify the genetic factors associated with ICAS and their correlation with clinical features. We also conducted a phenome-wide association study (PheWAS) of the top variant identified via GWAS to determine its association with systemic disease. The GWAS involved 408 patients with ICAS and 349 healthy controls and utilized an Asian Screening Array of venous blood samples. The PheWAS was performed using genotypic and phenotypic data of the Biobank Japan Project, which contained information on 46 diseases and 60 quantitative trait data from > 150,000 Japanese individuals. The GWAS revealed that the East Asian-specific functional variant of RNF213, rs112735431 (c.14429G > A, p.Arg4810Lys), was associated with ICAS (odds ratio, 12.3; 95% CI 5.5 to 27.5; P = 7.8 × 10^-10). Stratified analysis within ICAS cases demonstrated that clinical features of those with and without the risk allele were different. PheWAS indicated that high blood pressure and angina were significantly associated with RNF213 rs112735431. The first GWAS of ICAS, which stratifies subpopulations within the ICAS cases with distinct clinical features, revealed that RNF213 rs112735431 was the most significant variant associated with ICAS. Thus, RNF213 rs112735431 shows potential as an important clinical biomarker that characterizes pleiotropic risk in various vascular diseases, such as blood pressure and angina, thereby facilitating personalized medicine for systemic vascular diseases in East Asian populations.

Recognition of pathogen-derived sphingolipids in Arabidopsis

In plants, many invading microbial pathogens are recognized by cell-surface pattern recognition receptors, which induce defense responses. Here, we show that the ceramide Phytophthora infestans-ceramide D (Pi-Cer D) from the plant pathogenic oomycete P. infestans triggers defense responses in Arabidopsis. Pi-Cer D is cleaved by an Arabidopsis apoplastic ceramidase, NEUTRAL CERAMIDASE 2 (NCER2), and the resulting 9-methyl-branched sphingoid base is recognized by a plasma membrane lectin receptor-like kinase, RESISTANT TO DFPM-INHIBITION OF ABSCISIC ACID SIGNALING 2 (RDA2). 9-Methyl-branched sphingoid base is specific to microbes and induces plant immune responses by physically interacting with RDA2. Loss of RDA2 or NCER2 function compromised Arabidopsis resistance against an oomycete pathogen. Thus, we elucidated the recognition mechanisms of pathogen-derived lipid molecules in plants.

Composition-dependent sign inversion of the Soret coefficient of SiO2 in binary borosilicate melts

Using a laser-induced local-heating experiment combined with temperature analysis, we observed the composition-dependent sign inversion of the Soret coefficient of SiO2 in binary silicate melts, which was successfully explained by a modified Kempers model used for describing the Soret effect in oxide melts. In particular, the diffusion of SiO2 to the cold side under a temperature gradient, which is an anomaly in silicate melts, was observed in the SiO2-poor compositions. The theoretical model indicates that the thermodynamic mixing properties of oxides, partial molar enthalpy of mixing, and partial molar volume are the dominant factors for determining the migration direction of the SiO2 component under a temperature gradient.

Toward Self-Modifying Bio-Soft Robots

Soft robotics can dramatically increase the affinity between machines and biological systems. Designing the machine/device to be soft and deformable allows the biological system to interact with the robotic system(s) mechanically, electronically, and chemically. This advantage is evident from the rapid growth of collaborative robotics, where a robot can be mechanically guided by an operator to learn motions from them without the need for coding. This letter introduces a method for combining a soft robotic system with a biological system, demonstrated through a series of case studies of ongoing research projects. These various projects have a common purpose in creating self-modifying bio-soft robots.

Development of Living “Bio-Robots” for Autonomous Actuations

The implementation of autonomous functions, such as autonomous actuation, self-healing, and learning functions, has been a potent strategy to realize adaptation abilities against changes in environments and sudden incidents. Organic materials, such as living cells and tissues, can be used as robot parts for the implementation of autonomous functions because they can modify biological functions and remodel tissue morphologies in response to the environment. A brain organoid is a cell aggregate formed by recapitulating the development processes of the fetal brain in vitro. Because the brain organoid reproduces complex 3D structures and various cells, it can be used as a living regulator of robots for implementing complex autonomous functions. In contrast, engineered muscle tissues constructed by culturing myoblasts with biomaterials can also be used as a living actuator for robots. Therefore, to implement autonomous functions for robots, we have proposed methods for connecting the brain organoid with engineered muscle tissue and for co-culturing complex in a culture vessel.

Speciation of tin ions in oxide glass containing iron oxide through solvent extraction and inductively coupled plasma atomic emission spectrometry after the decomposition utilizing ascorbic acid

Determining the concentrations of different Sn ions in glass containing iron oxide by wet chemical analysis is a challenge because a redox reaction occurs between Sn²⁺ and Fe³⁺. A chemical analysis method for determining the concentrations of Sn²⁺ and Sn⁴⁺ in soda lime glass containing iron oxide was proposed. A mixture of ascorbic acid, hydrochloric acid, and hydrofluoric acid was used to decompose the sample in a vessel with nitrogen flow. Ascorbic acid functioned as a reductant for Fe³⁺. Subsequently, the Sn²⁺ were separated as a diethyldithiocarbamate complex. Furthermore, inductively coupled plasma atomic emission spectroscopy was used to determine the concentrations of Sn⁴⁺ and total Sn, from which the concentration of Sn²⁺ can be calculated. The results were validated by comparing ratios of Sn²⁺ to total Sn to results obtained using Mössbauer spectroscopy. The results were in agreement, thereby validating the use of the proposed approach.

Overall structure of fully assembled cyanobacterial KaiABC circadian clock complex by an integrated experimental-computational approach

In the cyanobacterial circadian clock system, KaiA, KaiB and KaiC periodically assemble into a large complex. Here we determined the overall structure of their fully assembled complex by integrating experimental and computational approaches. Small-angle X-ray and inverse contrast matching small-angle neutron scatterings coupled with size-exclusion chromatography provided constraints to highlight the spatial arrangements of the N-terminal domains of KaiA, which were not resolved in the previous structural analyses. Computationally built 20 million structural models of the complex were screened out utilizing the constrains and then subjected to molecular dynamics simulations to examine their stabilities. The final model suggests that, despite large fluctuation of the KaiA N-terminal domains, their preferential positionings mask the hydrophobic surface of the KaiA C-terminal domains, hindering additional KaiA-KaiC interactions. Thus, our integrative approach provides a useful tool to resolve large complex structures harboring dynamically fluctuating domains.

The revealed full KaiA₁₂B₆C₆ complex is assembled including the dynamic and asynchronous KaiA N-terminal domains that have been missing in cryo-EM structures.

Prognostic value of machine learning for acute heart failure

Funding Acknowledgements

Type of funding sources: None.

Background

At onset of acute heart failure (AHF), various clinical fundamental parameters including vital sign, laboratory data, or initial treatment were investigated, and we can roughly estimate the prognosis. However, machine learning method for prediction of the prognosis was not studied.

Purpose

To elucidate prognostic value of machine learning for AHF comparing conventional statistical model.

Methods

We enrolled consecutive 300 patients with AHF (79.5 ± 12.1 years, 158 Males). Patients with acute coronary syndrome, mechanical circulatory support cases, and cardio-pulmonary arrest cases were excluded. The patients were randomly divided into 80% (240 cases) and 20% (60 cases), and the former was used as train data, and the latter as validation data. Objective variable was set as cardiac death in one year. First, logistic regression analysis with Akaike’s information criterion (AIC) was performed, and extracted predictive parameters. The predictive model for the cardiac prognosis was constructed by cut-off value of ROC curve analysis of propensity score was calculated. Next, machine learning (random forest method and deep learning) to build predictive model was performed with the predictors. Finally, accuracy of each predictive model was compared.

Results

Thirty cases showed cardiac death in one year. Logistic regression with AIC extracted 8  predictors, and the cut off-value of propensity score with the 6 parameters was 0.110. The accuracy was 0.714 and area under ROC (AUROC) was 0.836. Conversely, random forest method demonstrated the accuracy as 0.927, AUROC 0.860. On deep learning, the accuracy was 0.937 and AUROC 0.901. 

The top 4 high feature importance of random forest were Cl/red blood cell count/pH/Anion Gap. However, accuracy of those predictors was lower than that of machine learning.

Conclusion

Machine learning was a powerful tool to predict cardiac prognosis of AHF, comparing with conventional statistical model. Abstract Figure. Statistical model

An ultrafast piezoelectric Z-scanner with a resonance frequency above 1.1 MHz for high-speed atomic force microscopy

The Z-scanner is the major component limiting the speed performance of all current high-speed atomic force microscopy systems. Here, we present an ultrafast piezoelectric Z-scanner with a resonance frequency above 1.1 MHz, achieving a record response time of ∼0.14 µs, approximately twice as fast as conventional piezoelectric-based Z-scanners. In the mechanical design, a small piezo-stack is supported at its bottom four vertices on a cone-like hollow, allowing the resonance frequency of the Z-scanner to remain as high as that of the piezo in free vibration. Its maximum displacement, ∼190 nm at 50 V, is large enough for imaging bio-molecules. For imaging bio-molecules in a buffer solution, the upper half of the Z-scanner is wrapped in a thin film resistant to water and chemicals, providing an excellent waterproof and mechanical durability without lowering the resonance frequency. We demonstrate that this Z-scanner can observe actin filaments, fragile biological polymers, for more than five times longer than the conventional Z-scanner at a tip velocity of 800 µm/s.

RNF213 p.Arg4810Lys Heterozygosity in Moyamoya Disease Indicates Early Onset and Bilateral Cerebrovascular Events

The relationship between RNF213 c.14429G > A (p.Arg4810Lys) heterozygous variants and clinical manifestation in patients with Moyamoya disease (MMD) remains unclear. We performed a retrospective cohort analysis to clarify the genotype-phenotype correlation of this RNF213 hotspot variant in MMD patients, especially between wild-type (GG) and heterozygous (GA) genotypes. Clinical and genetic data were obtained from patients diagnosed with MMD in our institutions between October 2011 and November 2020. Clinical data included age, sex, neurological status at diagnosis, medical history, smoking history, alcohol intake, and family history. Of the 225 enrolled patients, 160 (71.1%) were symptomatic, 3 (1.3%) had the homozygous variant, and 149 (66.2%) had the heterozygous variant (GA). Analysis of all enrolled patients showed that the GA group was prone to present bilateral symptoms (p = 0.008) and progressive status (Suzuki grade ≥ 4; p = 0.017). Analysis limited to symptomatic patients revealed that the GA group had bilateral symptoms (p = 0.017), younger age at onset (p = 0.043), and, in particular, a higher proportion of onset before 25 years of age (p = 0.021). Multivariate logistic regression analysis of overall patients revealed that earlier age at diagnosis (p < 0.001, OR 0.936, 95% CI 0.914-0.959) and GA group (p = 0.017, OR 3.326, 95%CI 1.237-8.941) were significantly associated with bilateral symptoms. MMD patients diagnosed at a young age with the RNF213 heterozygous variant should be followed up with consideration of possible contralateral stroke if one hemisphere is already symptomatic or of early cerebrovascular events if bilateral hemispheres are asymptomatic.

Distinct association of VEGF-C and VEGF-D with prognosis in patients with chronic heart failure: the PREHOSP-CHF study

Background

The lymphatic system has been suggested to play an important role in cardiovascular (CV) diseases including heart failure (HF). Vascular endothelial growth factor C (VEGF-C) and VEGF-D are key regulators of lymphoangiogenesis.

Purpose

To investigate the association of VEGF-C and VEGF-D with prognosis in patients with chronic HF (CHF).

Methods

The PREHOSP-CHF study is a multicenter prospective cohort study to determine the predictive value of angiogenesis-related biomarkers in CHF. A total of 1,024 patients (mean age, 75.5±12.6 years; male, 58.7%) admitted to acute decompensated HF were included in the analyses. The primary outcome was MACE defined as a composite of CV death or HF hospitalization. The secondary outcomes were all-cause death, CV death, and HF hospitalizations. Serum levels of VEGF-C and VEGF-D, as well as N-terminal pro B-type natriuretic peptide (NT-proBNP), high sensitivity cardiac troponin-I (hs-cTnI), high sensitive C reactive protein (hs-CRP), VEGF, and soluble VEGF receptor-2 (sVEGFR-2) were measured at the time of discharge. Patients were followed-up over two years.

Results

Median [interquartile range] of VEGF-C and VEGF-D levels were 4821 [3633–6131] pg/ml and 404 [296–559] pg/ml, respectively. In multivariate stepwise regression analysis, independent determinants of VEGF-C levels were younger age, female gender, absence of prior HF hospitalization, chronic kidney disease, and anemia, lower ejection fraction, lower NT-proBNP levels, higher VEGF levels, and higher sVEGFR-2 levels, while those of VEGF-D levels were lower body mass index, presence of diabetes and atrial fibrillation, and higher NT-proBNP levels. During the follow-up, a total of 209 (20.4%) all-cause deaths, 112 (10.9%) CV deaths, and 309 (30.2%) HF hospitalizations occurred. After adjusting for established risk factors and CV biomarkers, VEGF-C levels were significantly and inversely associated with the incidence of MACE and non-CV death (Fig.1, model 4). On the other hand, VEGF-D levels were significantly and positively associated with the incidence of HF hospitalization (Fig. 1, model 4). When we divided the patients into 4 groups based on the median of VEGF-C and VEGF-D levels, patients with low VEGF-C and high VEGF-D showed significantly higher incidence of MACE, all-cause death, CV death, and HF hospitalization compared to those with high VEGF-C and low VEGF-D (Fig. 2).

Conclusions

Among patients with CHF, VEGF-C and VEGF-D had different characteristic and association with the incidence of adverse events. VEGF-C levels were inversely associated with the incidence of MACE and non-CV death, and VEGF-D levels were positively associated with the incidence of HF hospitalization. These results suggests different effects of VEGF-C and VEGF-D in CHF. Combination of VEGF-C and VEGF-D enables us to make good risk stratification in patients with CHF.

Funding Acknowledgement

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Grant-in-Aid for Clinical Research from the National Hospital Organization Figure 1Figure 2

Diagnostic performance of deep learning on 12-leads electrocardiography for recurrence after pulmonary vein isolation in patients with persistent atrial fibrillation

Background

Several patients with persistent atrial fibrillation (per-AF) suffer from recurrence after pulmonary vein isolation (PVI). Various methods to predict the recurrence were tried, but deep learning on 12-leads electrocardiography (ECG) after PVI was not studied.

Purpose

To elucidate diagnostic performance of deep learning on 12-leads ECG after PVI in patients with per-AF

Methods

We enrolled consecutive 109 patients with per-AF who underwent PVI (68.8±10.0 years, 83 males) excluding failure cases. We defined recurrence in 3–12 months after PVI. From the ECG just after PVI, five beats of each lead were sampled separately. Deep learning (convolutional neural network on bitmap ECG image) was performed by transfer learning of Inception-Resnet-V2 model. Gradient weighted class activation color mapping (GradCam) was performed to detect convolutional importance in the lead.

Results

Thirty-six patients showed recurrence in the period. Lead II (accuracy 0.701), aVR (0.690) were the top 2 leads of prediction, which showed larger accuracy than statistical accuracies of Non PV foci = SVC (accuracy = 0.541) and left atrial diameter &gt;50mm (0.596). In lead II, GradCam spotlighted strong convolution of latter half of P wave in recurrent case, and former half of P wave and T wave in no-recurrent case.

Conclusions

Deep learning on ECG was a powerful tool to predict recurrence of per-AF after PVI.

Funding Acknowledgement

Type of funding sources: None. Results of deep learningResults of GradCam

Intracellular localization of AMP deaminase and its novel role in BCAA and lipid metabolism in diabetic cardiomyopathy

Background

A metabolomic study in the human heart suggested a pivotal role of amino acid (AA) metabolism in fatty acid oxidation, which is dysregulated in type 2 diabetes mellitus (T2DM) and heart failure. We previously reported that aberrant up-regulation of AMP deaminase 3 (AMPD3) impairs cardiac energetics in T2DM hearts, and AMPD3 was recently shown to be activated by fasting and to promote AA metabolism and fatty acid oxidation in skeletal muscle. A sodium glucose cotransporter 2 inhibitor (SGLT2i) has been shown to augment systemic AA metabolism, but its effect on cardiac AA metabolism remains unknown.

Purpose

We hypothesized that AMPD3 has a role in AA and lipid metabolism in cardiomyocytes and that the protective effect of an SGLT2i in diabetic hearts is mediated by modification of AA and lipid metabolism.

Methods and results

Proteomic analyses of AMPD3 immunoprecipitates in rat hearts revealed that AMPD3 interacted with the E1α and E2 components of the BCKDH complex, a rate-limiting enzyme of branched-chain AA (BCAA) catabolism. Immunoblotting using subcellular fractions revealed that BCKDH localized not only in the mitochondria matrix but also in the cytosol and endoplasmic reticulum (ER) and that AMPD3 interacted with BCKDH in the cytosol and ER. Despite comparable expression of BCKDH components and phosphorylation of E1α at Ser293, significant accumulation of BCAA was observed in T2DM rats (OLETF; 317±30 nmol/g) compared to that in control rats (LETO; 213±16 nmol/g), and the accumulation of BCAA was accompanied by up-regulation of AMPD3 in the cytosol and ER by 98% and 231%, respectively. In cardiomyocytes, disruption of BCAA catabolism by knockdown of BCKDH-E1α resulted in a 5.8-fold increase in AMPD3 at the transcriptional level and blunted lipid droplet biogenesis in response to a long-chain fatty acid challenge. Next, myocardial infarction (MI) was induced in LETO and OLETF pretreated with empagliflozin (10 mg/kg/day, 14 days) or a vehicle. Pathway analysis of cardiac metabolites revealed arginine biosynthesis and BCAA metabolism as the most significantly changed pathways with empagliflozin, with BCAA (791±187 nmol/g), glutamate, glutamine and urea being significantly increased. Empagliflozin restored myocardial ATP and survival after MI in OLETF to levels comparable to those in LETO. Electron microscopy showed a significantly higher prevalence of myocardium lipid droplets in OLETF, which was further increased by empagliflozin.

Conclusions

The results support the hypotheses that imbalance of extra-mitochondrial AMPD3-BCKDH interaction underlies dysregulated BCAA metabolism in T2DM hearts and that activation of cardiac AA metabolism by an SGLT2i normalizes fatty acid overload through sequestration into intracellular lipid droplets.

Funding Acknowledgement

Type of funding sources: Foundation. Main funding source(s): Boehringer Ingelheim

Impact of atrial fibrillation on soluble fms-like tyrosine kinase-1 and cardiovascular events in patients with suspected or known coronary artery disease: the EXCEED-J study

Background

Soluble fms-like tyrosine kinase-1 (sFlt-1), a vascular endothelial growth factor (VEGF) antagonist, has been suggested as a marker of endothelial dysfunction. Circulating sFlt-1 levels are associated with adverse outcomes in patients with preeclampsia, chronic kidney disease, and heart failure. Atrial fibrillation (AF) and coronary artery disease (CAD) are both associated with endothelial dysfunction. However, whether sFlt-1 can predict cardiovascular (CV) events and whether AF modifies the relationship between sFlt-1 and CV events in patients with suspected or known CAD are unknown.

Methods

We performed a nationwide, multicenter, prospective cohort study to determine the prognostic value of sFlt-1 and other biomarkers in patients with suspected or known CAD undergoing elective angiography. Heparin-free fasting serum was collected from the peripheral vein to determine levels of sFlt-1, VEGF, placental growth factor, cystatin C, neutrophil gelatinase-associated lipocalin, N-terminal pro-brain natriuretic peptide (NT-proBNP), high-sensitivity cardiac troponin-I (hs-cTnI), and high-sensitivity C-reactive protein (hs-CRP). The primary outcome was 3-point major adverse CV events (3P-MACE) defined as a composite of CV death, nonfatal myocardial infarction, and nonfatal stroke. The secondary outcomes were all-cause death, CV death, and 5P-MACE defined as a composite of 3P-MACE, heart failure hospitalization, and coronary/peripheral artery revascularization.

Results

3311 patients were consecutively enrolled between Nov 2013 and May 2017. After excluding 56 ineligible patients, 3255 patients (324 AF and 2931 non-AF) were followed up over 3 years (follow-up rate, 99%). During the follow-up, 156 patients developed 3P-MACE, 215 died from any cause, 82 died from cardiovascular disease, and 1361 developed 5P-MACE. The sFlt-1 level was significantly higher in AF compared to non-AF patients (p&lt;0.001). Stepwise regression analysis revealed that the sFlt-1 level was independently associated with AF. After adjusting for potential clinical confounders, serum levels of sFlt-1, NT-proBNP, hs-cTnI and cystatin C, but not other biomarkers, were significantly associated with 3P-MACE in the entire cohort. These associations were still significant in non-AF patients, whereas only the sFlt-1 level was significantly associated with 3P-MACE in AF patients. Serum levels of sFlt-1, but not other biomarkers, were also significantly associated with CV death in AF patients. Among the biomarkers, only the hs-CRP level was significantly associated with all-cause death, and no biomarker was significantly associated with 5P-MACE in AF patients. Furthermore, sFlt-1 provided an incremental prognostic information for 3P-MACE to the model with potential clinical confounders in AF, but not in non-AF patients.

Conclusions

Serum levels of sFlt-1 were significantly associated with 3P-MACE in patients with suspected or known CAD. This association was pronounced in AF patients.

Funding Acknowledgement

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): The EXCEED-J study is supported by Health Labour Sciences Research Grant (2013-2014), AMED (2015-2017, Grant Number JP17ek0210008) and Grant-in-Aid for Clinical Research from the National Hospital Organization (2018-2020).

Outcomes of Dissection Angles as Predictor of Restenosis after Drug-Coated Balloon Treatment

AIM

The predictors of restenosis after endovascular therapy (EVT) with paclitaxel drug-coated balloons (DCBs) have not been clearly established. The present study aimed to investigate the association of post-procedural dissection, as evaluated using intravascular ultrasound (IVUS), with the risk of restenosis following femoropopliteal EVT with paclitaxel DCBs.

METHODS

In the present single-center retrospective study, 60 de novo femoropopliteal lesions (44 patients) that underwent EVT with DCBs, without bail-out stenting, were enrolled. The primary outcome was 1-year primary patency. Risk factors for restenosis were evaluated using a Cox proportional hazards regression model and random survival forest analysis.

RESULTS

The 1-year primary patency rate was 57.2% [95% confidence interval, 45%-72%]. IVUS-evaluated post-procedural dissection was significantly associated with the risk of restenosis (P=0.002), with the best cutoff point of 64º [range, 39º-83º]. The random survival forest analysis showed that the variable importance measure of IVUS-evaluated dissection was significantly lower than that of the reference vessel diameter (P＜0.001), not different from that of the lesion length (P=0.41), and significantly higher than that of any other clinical feature (all P＜0.05).

CONCLUSION

IVUS-evaluated post-procedural dissection was associated with 1-year restenosis following femoropopliteal EVT with DCB.