Recombinant human lecithin-cholesterol acyltransferase in patients with atherosclerosis: phase 2a primary results and phase 2b design.

AIMS: Reverse cholesterol transport (RCT) removes cholesterol and stabilizes vulnerable plaques. In addition, high-density lipoprotein (HDL) may be cardioprotective in acute myocardial infarction (MI). Lecithin-cholesterol acyltransferase (LCAT) may enhance RCT. The objective of this study was to investigate the pharmacokinetics, pharmacodynamics, and safety of multiple ascending doses of recombinant human LCAT (MEDI6012) to inform a Phase 2b programme. METHODS AND RESULTS: This was a randomized, blinded, placebo-controlled, dose-escalation Phase 2a study of MEDI6012. Patients were randomized into one of four cohorts (40, 120, 300 mg IV weekly ×3 doses, or 300 mg IV-push, 150 mg at 48 h and 100 mg at 7 days). All cohorts were planned to randomize 6:2 (MEDI6012 vs. placebo). The primary endpoints were baseline-adjusted area under the curve (AUC) from 0 to 96 h post dose 3 (AUC 0-96 h) for HDL-C, HDL cholesteryl ester (HDL-CE), and total cholesteryl ester (CE). The primary safety endpoints were treatment-emergent adverse events. A total of 32 patients were randomized. MEDI6012 significantly increased AUC 0-96 h for HDL-C, HDL-CE and CE in a graded fashion with increasing doses. Relative to placebo, MEDI6012 increased HDL-C at Day 19 by 66% (95% CI 33-99, P = 0.014) with 120 mg and 144% (95% CI 108-181, P < 0.001) with 300 mg. An IV-push increased HDL-C by 40.8% at 30 min. Overall adverse events were similar between groups with no severe, life-threatening/fatal adverse events, or neutralizing antibodies. CONCLUSIONS: Multiple ascending doses of MEDI6012 were safe and well tolerated and significantly increased HDL-C, HDL-CE and CE in a dose-related manner. These data support the ongoing Phase 2b programme investigating MEDI6012 in ST-elevation MI.

Prevention of arterial and venous thrombotic events in symptomatic peripheral arterial disease patients after lower extremity revascularization in the VOYAGER PAD trial: Dual anticoagulant/antiplatelet regimen vs antiplatelet therapy alone.

BACKGROUND: Vascular disease burden after lower extremity revascularization (LER) comprises more than the first event, more vascular beds than the local arteries, and more than one clinical event type. OBJECTIVES: Assess total arterial and venous thrombotic burden after LER for symptomatic peripheral artery disease (PAD) and effect of low-dose anticoagulation added to low-dose antiplatelet therapy. PATIENTS/METHODS: VOYAGER PAD randomized 6564 symptomatic PAD patients undergoing LER to rivaroxaban 2.5 mg twice-daily or placebo on aspirin background. Marginal proportional-hazards models used to generate treatment hazard ratios and associated 95% CIs for first and total events; non-thrombotic deaths treated as competing terminal events. Incidence rates calculated as number of events per 100 patient-years follow-up. RESULTS: Over 2.5 years (median), first and total thrombotic event rates: 7.1 and 10.3 events/100 patient-years, respectively, in placebo group. Two-thirds (925/1372) of total thrombotic events (arterial 95%, venous 5%) were nonfatal first events. Nearly one-third of patients with first event had a second arterial or venous thrombotic event. Rivaroxaban plus aspirin reduced first and total arterial and venous thrombotic events to 5.4 and 7.9 events/100 patient-years, respectively, a reduction in total thrombotic events over aspirin of 23% (HR: 0.77, 95%CI: 0.67-0.89, p = .0005), preventing 6.1 total arterial and venous thrombotic events at 3 years. CONCLUSIONS: Assessing total arterial and venous thrombotic events, not just first events, provides more complete information about disease burden and absolute on-treatment impact. Following LER, judicious modulation of more than one coagulation pathway can provide broader benefit than intensifying inhibition of one hemostatic system component.

Identification of H3K4me1-associated proteins at mammalian enhancers.

Enhancers act to regulate cell-type-specific gene expression by facilitating the transcription of target genes. In mammalian cells, active or primed enhancers are commonly marked by monomethylation of histone H3 at lysine 4 (H3K4me1) in a cell-type-specific manner. Whether and how this histone modification regulates enhancer-dependent transcription programs in mammals is unclear. In this study, we conducted SILAC mass spectrometry experiments with mononucleosomes and identified multiple H3K4me1-associated proteins, including many involved in chromatin remodeling. We demonstrate that H3K4me1 augments association of the chromatin-remodeling complex BAF to enhancers in vivo and that, in vitro, H3K4me1-marked nucleosomes are more efficiently remodeled by the BAF complex. Crystal structures of the BAF component BAF45C indicate that monomethylation, but not trimethylation, is accommodated by BAF45C's H3K4-binding site. Our results suggest that H3K4me1 has an active role at enhancers by facilitating binding of the BAF complex and possibly other chromatin regulators.

Cell biology. Reversible centriole depletion with an inhibitor of Polo-like kinase 4.

Centrioles are ancient organelles that build centrosomes, the major microtubule-organizing centers of animal cells. Extra centrosomes are a common feature of cancer cells. To investigate the importance of centrosomes in the proliferation of normal and cancer cells, we developed centrinone, a reversible inhibitor of Polo-like kinase 4 (Plk4), a serine-threonine protein kinase that initiates centriole assembly. Centrinone treatment caused centrosome depletion in human and other vertebrate cells. Centrosome loss irreversibly arrested normal cells in a senescence-like G1 state by a p53-dependent mechanism that was independent of DNA damage, stress, Hippo signaling, extended mitotic duration, or segregation errors. In contrast, cancer cell lines with normal or amplified centrosome numbers could proliferate indefinitely after centrosome loss. Upon centrinone washout, each cancer cell line returned to an intrinsic centrosome number "set point." Thus, cells with cancer-associated mutations fundamentally differ from normal cells in their response to centrosome loss.

A Cell Biologist's Field Guide to Aurora Kinase Inhibitors.

Aurora kinases are essential for cell division and are frequently misregulated in human cancers. Based on their potential as cancer therapeutics, a plethora of small molecule Aurora kinase inhibitors have been developed, with a subset having been adopted as tools in cell biology. Here, we fill a gap in the characterization of Aurora kinase inhibitors by using biochemical and cell-based assays to systematically profile a panel of 10 commercially available compounds with reported selectivity for Aurora A (MLN8054, MLN8237, MK-5108, MK-8745, Genentech Aurora Inhibitor 1), Aurora B (Hesperadin, ZM447439, AZD1152-HQPA, GSK1070916), or Aurora A/B (VX-680). We quantify the in vitro effect of each inhibitor on the activity of Aurora A alone, as well as Aurora A and Aurora B bound to fragments of their activators, TPX2 and INCENP, respectively. We also report kinome profiling results for a subset of these compounds to highlight potential off-target effects. In a cellular context, we demonstrate that immunofluorescence-based detection of LATS2 and histone H3 phospho-epitopes provides a facile and reliable means to assess potency and specificity of Aurora A versus Aurora B inhibition, and that G2 duration measured in a live imaging assay is a specific readout of Aurora A activity. Our analysis also highlights variation between HeLa, U2OS, and hTERT-RPE1 cells that impacts selective Aurora A inhibition. For Aurora B, all four tested compounds exhibit excellent selectivity and do not significantly inhibit Aurora A at effective doses. For Aurora A, MK-5108 and MK-8745 are significantly more selective than the commonly used inhibitors MLN8054 and MLN8237. A crystal structure of an Aurora A/MK-5108 complex that we determined suggests the chemical basis for this higher specificity. Taken together, our quantitative biochemical and cell-based analyses indicate that AZD1152-HQPA and MK-8745 are the best current tools for selectively inhibiting Aurora B and Aurora A, respectively. However, MK-8745 is not nearly as ideal as AZD1152-HQPA in that it requires high concentrations to achieve full inhibition in a cellular context, indicating a need for more potent Aurora A-selective inhibitors. We conclude with a set of "good practice" guidelines for the use of Aurora inhibitors in cell biology experiments.

Effect of delavirdine on plasma lipids and lipoproteins in patients receiving antiretroviral therapy.

Plasma lipid and lipoprotein levels were measured at baseline and after 8 weeks of highly active antiretroviral therapy among patients receiving delavirdine with or without a protease inhibitor (PI). In patients receiving nucleoside reverse transcriptase inhibitors (NRTI) plus delavirdine, there was a statistically significant increase in cholesterol and HDL levels, whereas those receiving NRTI plus a PI had no significant change in their HDL levels. When delavirdine was combined with a PI, there was a more dramatic increase in both cholesterol and HDL concentrations.

Effect of long-chain ω-3 fatty acids and lutein + zeaxanthin supplements on cardiovascular outcomes: results of the Age-Related Eye Disease Study 2 (AREDS2) randomized clinical trial.

IMPORTANCE: Dietary supplements have been proposed as a mechanism to improve health and prevent disease. OBJECTIVE: To determine if supplementing diet with long-chain ω-3 polyunsaturated fatty acids or with macular xanthophylls results in a reduced rate of cardiovascular disease (CVD). DESIGN, SETTING, AND PARTICIPANTS: The Cardiovascular Outcome Study (COS) was an ancillary study of the Age-Related Eye Disease Study 2 (AREDS2), a factorial-designed randomized clinical trial of 4203 participants recruited from 82 US academic and community ophthalmology clinics, who were followed up for a median of 4.8 years. Individuals were eligible to participate if they were between the ages of 50 and 85 years, had intermediate or advanced age-related macular degeneration in 1 eye, and were willing to be randomized. Participants with stable, existing CVD (>12 months since initial event) were eligible to participate. Participants, staff, and outcome assessors were masked to intervention. INTERVENTIONS: Daily supplementation with long-chain ω-3 polyunsaturated fatty acids (350-mg docosahexaenoic acid [DHA] + 650-mg eicosapentaenoic acid [EPA]), macular xanthophylls (10-mg lutein + 2-mg zeaxanthin), combination of the two, or matching placebos. These treatments were added to background therapy of the AREDS vitamin and mineral formulation for macular degeneration. MAIN OUTCOMES AND MEASURES A composite outcome of myocardial infarction, stroke, and cardiovascular death with 4 prespecified secondary combinations of the primary outcome with hospitalized heart failure, revascularization, or unstable angina. RESULTS: Study participants were primarily white, married, and highly educated, with a median age at baseline of 74 years. A total of 602 cardiovascular events were adjudicated, and 459 were found to meet 1 of the study definitions for a CVD outcome. In intention-to-treat analysis, no reduction in the risk of CVD or secondary CVD outcomes was seen for the DHA + EPA (primary outcome: hazard ratio [HR], 0.95; 95% CI, 0.78-1.17) or lutein + zeaxanthin (primary outcome: HR, 0.94; 95% CI, 0.77-1.15) groups. No differences in adverse events or serious adverse event were seen by treatment group. The sample size was sufficient to detect a 25% reduction in CVD events with 80% power. CONCLUSIONS AND RELEVANCE: Dietary supplementation of long-chain ω-3 polyunsaturated fatty acids or macular xanthophylls in addition to daily intake of minerals and vitamins did not reduce the risk of CVD in elderly participants with age-related macular degeneration. TRIAL REGISTRATION: clinicaltrials.gov Identifier: NCT00345176.