Plasma ANGPTL8 Levels and Risk for Secondary Cardiovascular Events in Japanese Patients With Stable Coronary Artery Disease Receiving Statin Therapy.

BACKGROUND: The ability to predict secondary cardiovascular events could improve health of patients undergoing statin treatment. Circulating ANGPTL8 (angiopoietin-like protein 8) levels, which positively correlate with proatherosclerotic lipid profiles, activate the pivotal proatherosclerotic factor ANGPTL3. Here, we assessed potential association between circulating ANGPTL8 levels and risk of secondary cardiovascular events in statin-treated patients. METHODS: We conducted a biomarker study with a case-cohort design, using samples from a 2018 randomized control trial known as randomized evaluation of high-dose (4 mg/day) or low-dose (1 mg/day) lipid-lowering therapy with pitavastatin in coronary artery disease (REAL-CAD [Randomized Evaluation of Aggressive or Moderate Lipid-Lowering Therapy With Pitavastatin in Coronary Artery Disease])." From that study's full analysis set (n=12 413), we selected 2250 patients with stable coronary artery disease (582 with the primary outcome, 1745 randomly chosen, and 77 overlapping subjects). A composite end point including cardiovascular-related death, nonfatal myocardial infarction, nonfatal ischemic stroke, or unstable angina requiring emergent admission was set as a primary end point. Circulating ANGPTL8 levels were measured at baseline and 6 months after randomization. RESULTS: Over a 6-month period, ANGPTL8 level changes significantly decreased in the high-dose pitavastatin group, which showed 19% risk reduction of secondary cardiovascular events compared with the low-dose group in the REAL-CAD [Randomized Evaluation of Aggressive or Moderate Lipid-Lowering Therapy With Pitavastatin in Coronary Artery Disease] study. In the highest quartiles, relative increases in ANGPTL8 levels were significantly associated with increased risk for secondary cardiovascular events, after adjustment for several cardiovascular disease risk factors and pitavastatin treatment (hazard ratio in Q4, 1.67 [95% CI, 1.17-2.39). Subgroup analyses showed relatively strong relationships between relative ANGPTL8 increases and secondary cardiovascular events in the high-dose pitavastatin group (hazard ratio in Q4, 2.07 [95% CI, 1.21-3.55]) and in the low ANGPTL8 group at baseline (166

Efficacy and Safety of Warfarin for the Treatment of Venous Thromboembolism　- A Multicenter Prospective Observational Cohort Study in Japan (AKAFUJI Study).

BACKGROUND: A large-scale prospective study of the efficacy and safety of warfarin for the treatment of venous thromboembolism (VTE) has not been conducted in Japan. Therefore, we conducted a real-world prospective multicenter observational cohort study (AKAFUJI Study; UMIN000014132) to investigate the efficacy and safety of warfarin for VTE.Methods and Results: Between May 2014 and March 2017, 352 patients (mean [±SD] age 67.7±14.8 years; 57% female) with acute symptomatic/asymptomatic VTE were enrolled; 284 were treated with warfarin. The cumulative incidence of recurrent symptomatic VTE was higher in patients without warfarin than in those treated with warfarin (8.7 vs. 2.2 per 100 person-years, respectively; P=0.018). The cumulative incidence of bleeding complications was not significantly different between the 2 groups. The mean prothrombin time-international normalized ratio (PT-INR) during warfarin on-treatment was <1.5 in 180 patients, 1.5-2.5 in 97 patients, and >2.5 in 6 patients. The incidence of bleeding complications was significantly higher in patients with PT-INR >2.5, whereas the incidence of recurrent VTE was not significantly different between the 3 PT-INR groups. The cumulative incidence of recurrent VTE and bleeding complications did not differ significantly among those in whom VTE was provoked by a transient risk factor, was unprovoked, or was associated with cancer. CONCLUSIONS: Warfarin therapy with an appropriate PT-INR according to Japanese guidelines is effective without increasing bleeding complications, regardless of patient characteristics.

A Surgical Case of Partially Unroofed Coronary Sinus Atrial Septal Defect in an Elderly Patient Diagnosed by Preoperative Contrast-Enhanced Computed Tomography.

Unroofed coronary sinus syndrome is a rare congenital cardiac anomaly, involving some anatomical variations. Approximately 60% of patients with unroofed coronary sinus syndrome have a concomitant atrial septal defect, which is termed unroofed coronary sinus atrial septal defect (CSASD). The precise detection of these abnormalities has been usually difficult with conventional echocardiography, mostly due to its small and complex structures. Herein, we report a case with unroofed coronary sinus atrial septal defect, in which preoperative contrast-enhanced computed tomography (CT) was useful in the operative decision making. We successfully repaired the defective roof of the coronary sinus with a bovine patch, while eliminating the inter-atrial shunt. The patient's postoperative course was uneventful with no residual shunt.

Alleviated cerebral infarction in male mice lacking all nitric oxide synthase isoforms after middle cerebral artery occlusion.

PURPOSE: The role of the nitric oxide synthases (NOSs) system in cerebral infarction has been examined in pharmacological studies with non-selective NOSs inhibitors. However, due to the non-specificity of the non-selective NOSs inhibitors, its role remains to be fully elucidated. We addressed this issue in mice in which neuronal, inducible, and endothelial NOS isoforms were completely disrupted. METHODS AND RESULTS: We newly generated mice lacking all three NOSs by crossbreeding each single NOS-/- mouse. In the male, cerebral infarct size at 24 h after middle cerebral artery occlusion (MCAO) was significantly smaller in the triple n/i/eNOSs-/- genotype as compared with wild-type genotype. Neurological deficit score and mortality rate were also significantly lower in the triple n/i/eNOSs-/- than in the WT genotype. In contrast, in the female, there was no significant difference in the cerebral infarct size in the two genotypes. In the male triple n/i/eNOSs-/- genotype, orchiectomy significantly increased the cerebral infarct size, and in the orchiectomized male triple n/i/eNOSs-/- genotype, treatment with testosterone significantly reduced it. Cyclopaedic and quantitative comparisons of mRNA expression levels in cerebral infarct lesions between the male wild-type and triple n/i/eNOSs-/- genotypes at 1 h after MCAO revealed significant involvements of decreased oxidative stress and mitigated mitochondrial dysfunction in the alleviated cerebral infarction in the male triple n/i/eNOSs-/- genotype. CONCLUSIONS: These results provide the first evidence that the NOSs system exerts a deleterious effect against acute ischemic brain injury in the male.

Residual Coronary Risk Factors Associated With Long-Term Clinical Outcomes in Patients With Coronary Artery Disease Treated With High- vs. Low-Dose Statin Therapy　- REAL-CAD Substudy.

BACKGROUND: It remains unclear which comorbidities, other than lipid parameters, or combination of comorbidities, best predicts cardiovascular events in patients with known coronary artery disease (CAD) treated with statins. Therefore, we aimed to identify the nonlipid-related prognostic factors and risk stratification of patients with stable CAD enrolled in the REAL-CAD study.Methods and Results: Blood pressure, glucose level, and renal function were considered as risk factors in the 11,141 enrolled patients. The primary endpoint was a composite of cardiovascular death, nonfatal myocardial infarction, nonfatal ischemic stroke, and unstable angina. The secondary composite endpoint was the primary endpoint and/or coronary revascularization. A significantly worse prognosis at the primary endpoint was observed in the estimated glomerular filtration rate (eGFR) ≤60 group, and the combination of eGFR ≤60 and HbA1c ≥6.0 was the worst (hazard ratio (HR) 1.66; P<0.001). However, even in the eGFR >60 group, systolic blood pressure (SBP) ≥140 mmHg met the secondary endpoint (HR 1.33; P=0.006), and the combination of eGFR ≤60 and HbA1c ≥6.0 was also the worst at the secondary endpoint (HR 1.35; P=0.002). CONCLUSIONS: Regarding nonlipid prognostic factors contributing to the incidence of cardiovascular events in statin-treated CAD patients, renal dysfunction was the most significant, followed by poor glucose control and high SBP.

Clinical and Sociodemographic Factors Associated With Health-Related Quality of Life in Patients With Adult Congenital Heart Disease　- A Nationwide Cross-Sectional Multicenter Study.

BACKGROUND: Little is known about clinical or sociodemographic factors that influence health-related quality of life (HRQoL) in patients with adult congenital heart disease (ACHD).Methods and Results: We conducted a nationwide prospective cross-sectional multicenter study at 4 large ACHD centers in Japan. From November 2016 to June 2018, we enrolled 1,223 ACHD patients; 1,025 patients had an HRQoL score. Patients completed a questionnaire survey, including sociodemographic characteristics, and the 36-Item Short-Form Health Survey (SF-36). To determine factors associated with HRQoL, correlations between 2 SF-36 summary scores (i.e., physical component score [PCS] and mental component score [MCS]) and other clinical or sociodemographic variables were examined using linear regression analysis. In multivariable analysis, poorer PCS was significantly associated with 11 variables, including older age, higher New York Heart Association class, previous cerebral infarction, being unemployed, and limited participation in physical education classes and sports clubs. Poorer MCS was associated with congenital heart disease of great complexity, being part of a non-sports club, current smoking, and social drinking. Student status and a higher number of family members were positively correlated with MCS. CONCLUSIONS: This study demonstrates that HRQoL in ACHD patients is associated with various clinical and sociodemographic factors. Further studies are needed to clarify whether some of these factors could be targets for future intervention programs to improve HRQoL outcomes.

Systemic-pulmonary collateral supply associated with clinical severity of chronic thromboembolic pulmonary hypertension: a study using intra-aortic computed tomography angiography.

OBJECTIVES: To assess whether systemic-pulmonary collaterals are associated with clinical severity and extent of pulmonary perfusion defects in chronic thromboembolic pulmonary hypertension (CTEPH). METHODS: This prospective study was approved by a local ethics committee. Twenty-four patients diagnosed with inoperable CTEPH were enrolled between July 2014 and February 2017. Systemic-pulmonary collaterals were detected using pulmonary vascular enhancement on intra-aortic computed tomography (CT) angiography. The pulmonary enhancement parameters were calculated, including (1) Hounsfield unit differences (HUdiff) between pulmonary trunks and pulmonary arteries (PAs) or veins (PVs), namely HUdiff-PA and HUdiff-PV, on the segmental base; (2) the mean HUdiff-PA, mean HUdiff-PV, numbers of significantly enhanced PAs and PVs, on the patient base. Pulmonary perfusion defects were recorded and scored using the lung perfused blood volume (PBV) based on intravenous dual-energy CT (DECT) angiography. Pearson's or Spearman's correlation coefficients were used to evaluate correlations between the following: (1) segment-based intra-aortic CT and intravenous DECT parameters (2) patient-based intra-aortic CT parameters and clinical severity parameters or lung PBV scores. Statistical significance was set at p < 0.05. RESULTS: Segmental HUdiff-PV was correlated with the segmental perfusion defect score (r = 0.45, p < 0.01). The mean HUdiff-PV was correlated with the mean pulmonary arterial pressure (PAP) (r = 0.52, p < 0.01), cardiac output (rho = - 0.41, p = 0.05), and lung PBV score (rho = 0.43, p = 0.04). And the number of significantly enhanced PVs was correlated with the mean PAP (r = 0.54, p < 0.01), pulmonary vascular resistance (r = 0.54, p < 0.01), and lung PBV score (rho = 0.50, p = 0.01). CONCLUSIONS: PV enhancement measured by intra-aortic CT angiography reflects clinical severity and pulmonary perfusion defects in CTEPH. KEY POINTS: • Intra-aortic CT angiography demonstrated heterogeneous enhancement within the pulmonary vasculature, showing collaterals from the systemic arteries to the pulmonary circulation in CTEPH. • The degree of systemic-pulmonary collateral development was significantly correlated with the clinical severity of CTEPH and may be used to evaluate disease progression. • The distribution of systemic-pulmonary collaterals is positively correlated with perfusion defects in the lung segments in CTEPH.

Coronary Microvascular Dysfunction.

[Figure: see text].

Identification of Celastrol as a Novel Therapeutic Agent for Pulmonary Arterial Hypertension and Right Ventricular Failure Through Suppression of Bsg (Basigin)/CyPA (Cyclophilin A).

OBJECTIVE: Pulmonary arterial hypertension is characterized by abnormal proliferation of pulmonary artery smooth muscle cells and vascular remodeling, which leads to right ventricular (RV) failure. Bsg (Basigin) is a transmembrane glycoprotein that promotes myofibroblast differentiation, cell proliferation, and matrix metalloproteinase activation. CyPA (cyclophilin A) binds to its receptor Bsg and promotes pulmonary artery smooth muscle cell proliferation and inflammatory cell recruitment. We previously reported that Bsg promotes cardiac fibrosis and failure in the left ventricle in response to pressure-overload in mice. However, the roles of Bsg and CyPA in RV failure remain to be elucidated. Approach and Results: First, we found that protein levels of Bsg and CyPA were upregulated in the heart of hypoxia-induced pulmonary hypertension (PH) in mice and monocrotaline-induced PH in rats. Furthermore, cardiomyocyte-specific Bsg-overexpressing mice showed exacerbated RV hypertrophy, fibrosis, and dysfunction compared with their littermates under chronic hypoxia and pulmonary artery banding. Treatment with celastrol, which we identified as a suppressor of Bsg and CyPA by drug screening, decreased proliferation, reactive oxygen species, and inflammatory cytokines in pulmonary artery smooth muscle cells. Furthermore, celastrol treatment ameliorated RV systolic pressure, hypertrophy, fibrosis, and dysfunction in hypoxia-induced PH in mice and SU5416/hypoxia-induced PH in rats with reduced Bsg, CyPA, and inflammatory cytokines in the hearts and lungs. CONCLUSIONS: These results indicate that elevated Bsg in pressure-overloaded RV exacerbates RV dysfunction and that celastrol ameliorates RV dysfunction in PH model animals by suppressing Bsg and its ligand CyPA. Thus, celastrol can be a novel drug for PH and RV failure that targets Bsg and CyPA. Graphic Abstract: A graphic abstract is available for this article.

A Pilot Study of Whole-Brain Low-Intensity Pulsed Ultrasound Therapy for Early Stage of Alzheimer's Disease (LIPUS-AD): A Randomized, Double-Blind, Placebo-Controlled Trial.

The prevalence of Alzheimer's disease (AD) has been rapidly increasing worldwide. We have developed a novel angiogenic therapy with low-intensity pulsed ultrasound (LIPUS), which is effective and safe in animal models of AD and vascular dementia. We performed two trials of LIPUS therapy for AD (mild cognitive impairment due to AD and mild AD); a roll-in open trial for safety, and a randomized, double-blind, placebo-controlled (RCT) trial for efficacy and safety. The LIPUS therapy was performed for whole brain through the bilateral temporal bones for one hour 3 times a week as one session under the special conditions (1.3 MPa, 32 cycles, 5% duty cycle) we identified. The LIPUS therapy was performed for one session in the roll-in trial, and 6 sessions in the RCT trial with 3-month intervals for 1.5 years. The primary endpoint was ADAS-J cog scores. The RCT trial was terminated prematurely due to the COVID-19 pandemic. In the roll-in trial (N = 5), no adverse effects were noted. In the RCT trial (N = 22), the worsening of ADAS-J cog scores tended to be suppressed in the LIPUS group compared with the placebo group at week 72 (P = 0.257). When responders were defined as those with no worsening of ADAS-J cog scores at week 72, the prevalence was 50% (5/10) and 0% (0/5) in the LIPUS and placebo groups, respectively (P = 0.053). No adverse effects were noted. These results suggest that the LIPUS therapy is safe and tends to suppress cognitive impairment although a next pivotal trial with a large number of subjects is warranted.

Clinical characteristics and prognosis of patients with microvascular angina: an international and prospective cohort study by the Coronary Vasomotor Disorders International Study (COVADIS) Group.

AIMS: To provide multi-national, multi-ethnic data on the clinical characteristics and prognosis of patients with microvascular angina (MVA). METHODS AND RESULTS: The Coronary Vasomotor Disorders International Study Group proposed the diagnostic criteria for MVA. We prospectively evaluated the clinical characteristics of patients according to these criteria and their prognosis. The primary endpoint was the composite of major cardiovascular events (MACE), verified by institutional investigators, which included cardiovascular death, non-fatal myocardial infarction, non-fatal stroke, and hospitalization due to heart failure or unstable angina. During the period from 1 July 2015 to 31 December 2018, 686 patients with MVA were registered from 14 institutes in 7 countries from 4 continents. Among them, 64% were female and the main ethnic groups were Caucasians (61%) and Asians (29%). During follow-up of a median of 398 days (IQR 365-744), 78 MACE occurred (6.4% in men vs. 8.6% in women, P = 0.19). Multivariable Cox proportional hazard analysis disclosed that hypertension and previous history of coronary artery disease (CAD), including acute coronary syndrome and stable angina pectoris, were independent predictors of MACE. There was no sex or ethnic difference in prognosis, although women had lower Seattle Angina Questionnaire scores than men (P < 0.05). CONCLUSIONS: This first international study provides novel evidence that MVA is an important health problem regardless of sex or ethnicity that a diagnosis of MVA portends a substantial risk for MACE associated with hypertension and previous history of CAD, and that women have a lower quality of life than men despite the comparable prognosis.

The A118G single-nucleotide polymorphism in OPRM1 is a risk factor for asthma severity.

BACKGROUND: Although population studies have implicated emotional burden in asthma severity, the underlying genetic risk factors are not completely understood. We aimed to evaluate the genetic influence of a functional single-nucleotide polymorphism (SNP) in the stress-related µ-opioid receptor gene (OPRM1; A118G SNP, rs1799971) on asthma severity. METHODS: We initially assessed disease severity in asthmatic outpatients carrying A118G. Using an ovalbumin-induced experimental asthma rodent model harboring the functionally equivalent SNP, we investigated the mechanism by which this SNP influences the allergic immune response. RESULTS: Among 292 outpatients, 168 underwent airway hyperresponsiveness (AHR) to methacholine testing. Compared with patients carrying the AA and AG genotypes, those carrying the GG genotype exhibited enhanced AHR. The stress levels were presumed to be moderate among patients and were comparable among genotypes. Compared with Oprm1 AA mice, GG mice demonstrated aggravated asthma-related features and increased pulmonary interleukin-4+CD4+ effector and effector memory T cells under everyday life stress conditions. Intraperitoneal naloxone methiodide injection reduced effector CD4+ T cell elevation associated with increased eosinophil numbers in bronchoalveolar lavage fluid of GG mice to the levels in AA mice, suggesting that elevated Th2 cell generation in the bronchial lymph node (BLN) of GG mice induces enhanced eosinophilic inflammation. CONCLUSIONS: Without forced stress exposure, patients with asthma carrying the OPRM1 GG genotype exhibit enhanced AHR, attributable to enhanced Th2 cell differentiation in the regional lymph node. Further research is necessary to elucidate the role of the OPRM1 A118G genotype in the Th2 cell differentiation pathway in the BLN.

Ferroptosis is controlled by the coordinated transcriptional regulation of glutathione and labile iron metabolism by the transcription factor BACH1.

Ferroptosis is an iron-dependent programmed cell death event, whose regulation and physiological significance remain to be elucidated. Analyzing transcriptional responses of mouse embryonic fibroblasts exposed to the ferroptosis inducer erastin, here we found that a set of genes related to oxidative stress protection is induced upon ferroptosis. We considered that up-regulation of these genes attenuates ferroptosis induction and found that the transcription factor BTB domain and CNC homolog 1 (BACH1), a regulator in heme and iron metabolism, promotes ferroptosis by repressing the transcription of a subset of the erastin-induced protective genes. We noted that these genes are involved in the synthesis of GSH or metabolism of intracellular labile iron and include glutamate-cysteine ligase modifier subunit (Gclm), solute carrier family 7 member 11 (Slc7a11), ferritin heavy chain 1 (Fth1), ferritin light chain 1 (Ftl1), and solute carrier family 40 member 1 (Slc40a1). Ferroptosis has also been previously shown to induce cardiomyopathy, and here we observed that Bach1-/- mice are more resistant to myocardial infarction than WT mice and that the severity of ischemic injury is decreased by the iron-chelator deferasirox, which suppressed ferroptosis. Our findings suggest that BACH1 represses genes that combat labile iron-induced oxidative stress, and ferroptosis is stimulated at the transcriptional level by BACH1 upon disruption of the balance between the transcriptional induction of protective genes and accumulation of iron-mediated damage. We propose that BACH1 controls the threshold of ferroptosis induction and may represent a therapeutic target for alleviating ferroptosis-related diseases, including myocardial infarction.

Relation of renal function to mid-term prognosis of stable angina patients with high- or low-dose pitavastatin treatment: REAL-CAD substudy.

BACKGROUND: It has not yet been established whether higher-dose statins have beneficial effects on cardiovascular events in patients with stable coronary artery disease (CAD) and renal dysfunction. METHODS: The REAL-CAD study is a prospective, multicenter, open-label trial. As a substudy, we categorized patients by an estimated glomerular filtration rate (eGFR) as follows: eGFR ≥60 (n = 7,768); eGFR ≥45 and <60 (n = 3,176); and eGFR <45 mL/Min/1.73 m2 (n = 1,164), who were randomized to pitavastatin 4mg or 1mg therapy. The primary endpoint was a composite of cardiovascular death, non-fatal myocardial infarction, non-fatal ischemic stroke, or unstable angina, and was assessed by the log-rank test and Cox proportional hazards model. RESULTS: The baseline characteristics and medications were largely well-balanced between two groups. The magnitude of low-density lipoprotein cholesterol (LDL-C) reduction at 6 months in high- and low-dose pitavastatin groups was comparable among all eGFR categories. During a median follow-up of 3.9 years, high- compared with low-dose pitavastatin significantly reduced cardiovascular events in patients with eGFR ≥60 (hazard ratio (HR) 0.73; 95% confidence interval (CI) 0.58-0.91; P = .006), and reduced but not significant for patients with eGFR ≥45 and <60 (HR 0.85; 95% CI, 0.63-1.14; P = .27) or eGFR <45 mL/Min/1.73 m2 (HR 0.90; 95% CI 0.62-1.33; P = .61). An interaction test of treatment by eGFR category was not significant (P value for interaction = .30). CONCLUSION: Higher-dose pitavastatin therapy reduced LDL levels and cardiovascular events in stable CAD patients irrespective of eGFR level, although the effect on events appeared to be numerically lower in patients with lower eGFR.

ADAMTS8 Promotes the Development of Pulmonary Arterial Hypertension and Right Ventricular Failure: A Possible Novel Therapeutic Target.

RATIONALE: Pulmonary arterial hypertension (PAH) is characterized by pulmonary vascular remodeling with aberrant pulmonary artery smooth muscle cells (PASMCs) proliferation, endothelial dysfunction, and extracellular matrix remodeling. OBJECTIVE: Right ventricular (RV) failure is an important prognostic factor in PAH. Thus, we need to elucidate a novel therapeutic target in both PAH and RV failure. METHODS AND RESULTS: We performed microarray analysis in PASMCs from patients with PAH (PAH-PASMCs) and controls. We found a ADAMTS8 (disintegrin and metalloproteinase with thrombospondin motifs 8), a secreted protein specifically expressed in the lung and the heart, was upregulated in PAH-PASMCs and the lung in hypoxia-induced pulmonary hypertension (PH) in mice. To elucidate the role of ADAMTS8 in PH, we used vascular smooth muscle cell-specific ADAMTS8-knockout mice (ADAMTSΔSM22). Hypoxia-induced PH was attenuated in ADAMTSΔSM22 mice compared with controls. ADAMTS8 overexpression increased PASMC proliferation with downregulation of AMPK (AMP-activated protein kinase). In contrast, deletion of ADAMTS8 reduced PASMC proliferation with AMPK upregulation. Moreover, deletion of ADAMTS8 reduced mitochondrial fragmentation under hypoxia in vivo and in vitro. Indeed, PASMCs harvested from ADAMTSΔSM22 mice demonstrated that phosphorylated DRP-1 (dynamin-related protein 1) at Ser637 was significantly upregulated with higher expression of profusion genes (Mfn1 and Mfn2) and improved mitochondrial function. Moreover, recombinant ADAMTS8 induced endothelial dysfunction and matrix metalloproteinase activation in an autocrine/paracrine manner. Next, to elucidate the role of ADAMTS8 in RV function, we developed a cardiomyocyte-specific ADAMTS8 knockout mice (ADAMTS8ΔαMHC). ADAMTS8ΔαMHC mice showed ameliorated RV failure in response to chronic hypoxia. In addition, ADAMTS8ΔαMHC mice showed enhanced angiogenesis and reduced RV ischemia and fibrosis. Finally, high-throughput screening revealed that mebendazole, which is used for treatment of parasite infections, reduced ADAMTS8 expression and cell proliferation in PAH-PASMCs and ameliorated PH and RV failure in PH rodent models. CONCLUSIONS: These results indicate that ADAMTS8 is a novel therapeutic target in PAH.

Hippo Deficiency Leads to Cardiac Dysfunction Accompanied by Cardiomyocyte Dedifferentiation During Pressure Overload.

RATIONALE: The Hippo pathway plays an important role in determining organ size through regulation of cell proliferation and apoptosis. Hippo inactivation and consequent activation of YAP (Yes-associated protein), a transcription cofactor, have been proposed as a strategy to promote myocardial regeneration after myocardial infarction. However, the long-term effects of Hippo deficiency on cardiac function under stress remain unknown. OBJECTIVE: We investigated the long-term effect of Hippo deficiency on cardiac function in the presence of pressure overload (PO). METHODS AND RESULTS: We used mice with cardiac-specific homozygous knockout of WW45 (WW45cKO), in which activation of Mst1 (Mammalian sterile 20-like 1) and Lats2 (large tumor suppressor kinase 2), the upstream kinases of the Hippo pathway, is effectively suppressed because of the absence of the scaffolding protein. We used male mice at 3 to 4 month of age in all animal experiments. We subjected WW45cKO mice to transverse aortic constriction for up to 12 weeks. WW45cKO mice exhibited higher levels of nuclear YAP in cardiomyocytes during PO. Unexpectedly, the progression of cardiac dysfunction induced by PO was exacerbated in WW45cKO mice, despite decreased apoptosis and activated cardiomyocyte cell cycle reentry. WW45cKO mice exhibited cardiomyocyte sarcomere disarray and upregulation of TEAD1 (transcriptional enhancer factor) target genes involved in cardiomyocyte dedifferentiation during PO. Genetic and pharmacological inactivation of the YAP-TEAD1 pathway reduced the PO-induced cardiac dysfunction in WW45cKO mice and attenuated cardiomyocyte dedifferentiation. Furthermore, the YAP-TEAD1 pathway upregulated OSM (oncostatin M) and OSM receptors, which played an essential role in mediating cardiomyocyte dedifferentiation. OSM also upregulated YAP and TEAD1 and promoted cardiomyocyte dedifferentiation, indicating the existence of a positive feedback mechanism consisting of YAP, TEAD1, and OSM. CONCLUSIONS: Although activation of YAP promotes cardiomyocyte regeneration after cardiac injury, it induces cardiomyocyte dedifferentiation and heart failure in the long-term in the presence of PO through activation of the YAP-TEAD1-OSM positive feedback mechanism.

Identification of Celastramycin as a Novel Therapeutic Agent for Pulmonary Arterial Hypertension.

RATIONALE: Pulmonary arterial hypertension (PAH) is characterized by enhanced proliferation of pulmonary artery smooth muscle cells (PASMCs) accompanying increased production of inflammatory factors and adaptation of the mitochondrial metabolism to a hyperproliferative state. However, all the drugs in clinical use target pulmonary vascular dilatation, which may not be effective for patients with advanced PAH. OBJECTIVE: We aimed to discover a novel drug for PAH that inhibits PASMC proliferation. METHODS AND RESULTS: We screened 5562 compounds from original library using high-throughput screening system to discover compounds which inhibit proliferation of PASMCs from patients with PAH (PAH-PASMCs). We found that celastramycin, a benzoyl pyrrole-type compound originally found in a bacteria extract, inhibited the proliferation of PAH-PASMCs in a dose-dependent manner with relatively small effects on PASMCs from healthy donors. Then, we made 25 analogs of celastramycin and selected the lead compound, which significantly inhibited cell proliferation of PAH-PASMCs and reduced cytosolic reactive oxygen species levels. Mechanistic analysis demonstrated that celastramycin reduced the protein levels of HIF-1α (hypoxia-inducible factor 1α), which impairs aerobic metabolism, and κB (nuclear factor-κB), which induces proinflammatory signals, in PAH-PASMCs, leading to reduced secretion of inflammatory cytokine. Importantly, celastramycin treatment reduced reactive oxygen species levels in PAH-PASMCs with increased protein levels of Nrf2 (nuclear factor erythroid 2-related factor 2), a master regulator of cellular response against oxidative stress. Furthermore, celastramycin treatment improved mitochondrial energy metabolism with recovered mitochondrial network formation in PAH-PASMCs. Moreover, these celastramycin-mediated effects were regulated by ZFC3H1 (zinc finger C3H1 domain-containing protein), a binding partner of celastramycin. Finally, celastramycin treatment ameliorated pulmonary hypertension in 3 experimental animal models, accompanied by reduced inflammatory changes in the lungs. CONCLUSIONS: These results indicate that celastramycin ameliorates pulmonary hypertension, reducing excessive proliferation of PAH-PASMCs with less inflammation and reactive oxygen species levels, and recovered mitochondrial energy metabolism. Thus, celastramycin is a novel drug for PAH that targets antiproliferative effects on PAH-PASMCs.

Recent Advances in Vascular Imaging.

Recent advances in vascular imaging have enabled us to uncover the underlying mechanisms of vascular diseases both ex vivo and in vivo. In the past decade, efforts have been made to establish various methodologies for evaluation of atherosclerotic plaque progression and vascular inflammatory changes in addition to biomarkers and clinical manifestations. Several recent publications in Arteriosclerosis, Thrombosis, and Vascular Biology highlighted the essential roles of in vivo and ex vivo vascular imaging, including magnetic resonance image, computed tomography, positron emission tomography/scintigraphy, ultrasonography, intravascular ultrasound, and most recently, optical coherence tomography, all of which can be used in bench and clinical studies at relative ease. With new methods proposed in several landmark studies, these clinically available imaging modalities will be used in the near future. Moreover, future development of intravascular imaging modalities, such as optical coherence tomography-intravascular ultrasound, optical coherence tomography-near-infrared autofluorescence, polarized-sensitive optical coherence tomography, and micro-optical coherence tomography, are anticipated for better management of patients with cardiovascular disease. In this review article, we will overview recent advances in vascular imaging and ongoing works for future developments.

Marked Impairment of Endothelium-Dependent Digital Vasodilatations in Patients With Microvascular Angina: Evidence for Systemic Small Artery Disease.

OBJECTIVE: It remains to be elucidated whether and how endothelial functions are impaired in peripheral circulation of patients with coronary functional disorders, such as vasospastic angina (VSA) and microvascular angina (MVA). We simultaneously examined endothelial functions of peripheral conduit and resistance arteries in patients with coronary functional disorders, with a special reference to NO and endothelium-dependent hyperpolarization factors. Approach and Results: Based on the results of invasive coronary acetylcholine testing and coronary physiological measurements, we divided 43 patients into 3 groups; VSA, MVA, and VSA+MVA. Endothelium-dependent vasodilatations of the brachial artery and fingertip arterioles to intra-arterial infusion of bradykinin were simultaneously evaluated by ultrasonography and peripheral arterial tonometry, respectively. To assess NO and endothelium-dependent hyperpolarization factors, measurements were repeated after oral aspirin and intra-arterial infusion of NG-monomethyl-L-arginine. Additionally, endothelium-independent vasodilatations to sublingual nitroglycerin and plasma levels of biomarkers for endothelial functions were measured. Surprisingly, digital vasodilatations to bradykinin were almost absent in patients with MVA alone and those with VSA+MVA compared with those with VSA alone. Mechanistically, both NO- and endothelium-dependent hyperpolarization-mediated digital vasodilatations were markedly impaired in patients with MVA alone. In contrast, endothelium-independent vasodilatations to nitroglycerin were comparable among the 3 groups. Plasma levels of soluble VCAM (vascular cell adhesion molecule)-1 were significantly higher in patients with MVA alone compared with those with VSA alone. CONCLUSIONS: These results provide the first evidence that both NO- and endothelium-dependent hyperpolarization-mediated digital vasodilatations are markedly impaired in MVA patients, suggesting that MVA is a cardiac manifestation of the systemic small artery disease.

Endothelium in Coronary Macrovascular and Microvascular Diseases.

ABSTRACT: The endothelium plays a pivotal role in the regulation of vascular tone by synthesizing and liberating endothelium-derived relaxing factors inclusive of vasodilator prostaglandins (eg, prostacyclin), nitric oxide (NO), and endothelium-dependent hyperpolarization factors in a distinct blood vessel size-dependent manner. Large conduit arteries are predominantly regulated by NO and small resistance arteries by endothelium-dependent hyperpolarization factors. Accumulating evidence over the past few decades has demonstrated that endothelial dysfunction and coronary vasomotion abnormalities play crucial roles in the pathogenesis of various cardiovascular diseases. Structural and functional alterations of the coronary microvasculature have been coined as coronary microvascular dysfunction (CMD), which is highly prevalent and associated with adverse clinical outcomes in many clinical settings. The major mechanisms of coronary vasomotion abnormalities include enhanced coronary vasoconstrictive reactivity at epicardial and microvascular levels, impaired endothelium-dependent and endothelium-independent coronary vasodilator capacities, and elevated coronary microvascular resistance caused by structural factors. Recent experimental and clinical research has highlighted CMD as the systemic small artery disease beyond the heart, emerging modulators of vascular functions, novel insights into the pathogenesis of cardiovascular diseases associated with CMD, and potential therapeutic interventions to CMD with major clinical implications. In this article, we will summarize the current knowledge on the endothelial modulation of vascular tone and the pathogenesis of coronary macrovascular and microvascular diseases from bench to bedside, with a special emphasis placed on the mechanisms and clinical implications of CMD.