Targeting of Histone Acetyltransferase p300 by Cyclopentenone Prostaglandin Δ12-PGJ2 through Covalent Binding to Cys1438

This document is the Accepted Manuscript version of a Published Work that appeared in final form in Chemical Research in Toxicology, copyright © American Chemical Society after peer review and technical editing by the publisher. To access the final edited and published work see http://pubs.acs.org/doi/abs/10.1021/tx200383cInhibitors of histone acetyltransferases (HATs) are perceived to treat diseases like cancer, neurodegeneration, and AIDS. On the basis of previous studies, we hypothesized that Cys1438 in the substrate binding site could be targeted by Δ12-prostaglandin J2 (Δ12-PGJ2), a cyclopentenone prostaglandin (CyPG) derived from PGD2. We demonstrate here the ability of CyPGs to inhibit p300 HAT-dependent acetylation of histone H3. A cell-based assay system clearly showed that the α,β-unsaturation in the cyclopentenone ring of Δ12-PGJ2 was crucial for the inhibitory activity, while the 9,10-dihydro-15-deoxy- Δ12,14-PGJ2, which lacks the electrophilic carbon (at carbon 9), was ineffective. Molecular docking studies suggested that Δ12-PGJ2 places the electrophilic carbon in the cyclopentenone ring well within the vicinity of Cys1438 of p300 to form a covalent Michael adduct. Site-directed mutagenesis of the p300 HAT domain, peptide competition assay involving p300 wild type and mutant peptides, followed by mass spectrometric analysis confirmed the covalent interaction of Δ12-PGJ2 with Cys1438. Using biotinylated derivatives of Δ12-PGJ2 and 9,10-dihydro-15-deoxy- Δ12,14-PGJ2, we demonstrate the covalent interaction of Δ12-PGJ2 with the p300 HAT domain, but not the latter. In agreement with the in vitro filter binding assay, CyPGs were also found to inhibit H3 histone acetylation in cell-based assays. In addition, Δ12-PGJ2 also inhibited the acetylation of the HIV-1 Tat by recombinant p300 in in vitro assays. This study demonstrates, for the first time, that Δ12-PGJ2 inhibits p300 through Michael addition, where α,β-unsaturated carbonyl function is absolutely required for the inhibitory activity

Focused-attention meditation increases cognitive control during motor sequence performance: Evidence from the N2 cortical evoked potential

Previous work found that single-session focused attention meditation (FAM) enhanced motor sequence learning through increased cognitive control as a mechanistic action, although electrophysiological correlates of sequence learning performance following FAM were not investigated. We measured the persistent frontal N2 event-related potential (ERP) that is closely related to cognitive control processes and its ability to predict behavioural measures. Twenty-nine participants were randomised to one of three conditions reflecting the level of FAM experienced prior to a serial reaction time task (SRTT): 21 sessions of FAM (FAM21, N = 12), a single FAM session (FAM1, N = 9) or no preceding FAM control (Control, N = 8). Continuous 64-channel EEG were recorded during SRTT and N2 amplitudes for correct trials were extracted. Component amplitude, regions of interests, and behavioural outcomes were compared using mixed effects regression models between groups. FAM21 exhibited faster reaction time performances in majority of the learning blocks compared to FAM1 and Control. FAM21 also demonstrated a significantly more pronounced N2 over majority of anterior and central regions of interests during SRTT compared to the other groups. When N2 amplitudes were modelled against general learning performance, FAM21 showed the greatest rate of amplitude decline over anterior and central regions. The combined results suggest that FAM training provided greater cognitive control enhancement for improved general performance, and less pronounced effects for sequence-specific learning performance compared to the other groups. Importantly, FAM training facilitates dynamic modulation of cognitive control: lower levels of general learning performance was supported by greater levels of activation, whilst higher levels of general learning exhibited less activation

Reaction Pairing: A Diversity-Oriented Synthesis Strategy for the Synthesis of Diverse Benzofused Sultams

A reaction pairing strategy centered on utilization of a reaction triad (sulfonylation, SNAr addition and Mitsunobu alkylation) generating skeletally diverse benzofused tricyclic and bicyclic sultams is reported. Pairing sulfonylation and SNAr reactions yields bridged, tricyclic and bicyclic benzofused sultams. Application of the Mitsunobu reaction in a sulfonylation–Mitsunobu–SNAr pairing allows access to benzo-oxathiazocine-1,1-dioxides, while a simple change in the order of pairing to sulfonylation–SNAr–Mitsunobu affords structurally different, benzofused bridged tricyclic sultams

Temperature biofeedback and sleep: limited findings and methodological challenges

Given the close link between body temperature and sleep, the perspective of manipulating core and peripheral temperature by self-regulation techniques is very appealing. We report here on a series of attempts conducted independently in two laboratories to use self-regulation (biofeedback) of oral (central) and hand (peripheral) temperature, and measured the impact on sleep-onset latency, sleep architecture, and circadian phase. We found that hand temperature was more successful than oral temperature biofeedback. Moreover, an increase in hand temperature was associated with reduced sleep-onset latency. However, most participants found the procedure difficult to implement. The temperature response to biofeedback was reduced in the aged and weakest at the time of sleep onset, and there was not a systematic relationship between the change in temperature and change in sleep latency. Methodological limitations and individual differences may account for these results. Recommendations for future research are presented.Geneviève Forest, Cameron van den Heuvel, Kurt Lushington, Joseph De Koninc

Exploring chemical diversity via a modular reaction pairing strategy

The efficient synthesis of an 80-member library of unique benzoxathiazocine 1,1-dioxides by a microwave-assisted, intermolecular nucleophilic aromatic substitution (SNAr) diversification pathway is reported. Eight benzofused sultam cores were generated by means of a sulfonylation/SNAr/Mitsunobu reaction pairing protocol, and subsequently diversified by intermolecular SNAr with ten chiral, non-racemic amine/amino alcohol building blocks. Computational analyses were employed to explore and evaluate the chemical diversity of the library.Financial support of this work was provided by the National Institute of General Medical Sciences and is gratefully acknowledged (P50-GM069663 and P41-GM076302). In addition, funding from The University of Kansas for an Undergraduate Research Award (S.Y.) is gratefully acknowledged

Adenotonsillectomy and neurocognitive deficits in children with sleep disordered breathing

Copyright: © 2009 Kohler et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.Background: Sleep Disordered Breathing (SDB) is a common childhood disorder that encompasses a range of sleep-related upper airway obstruction. Children with SDB demonstrate significant neurocognitive deficits. Adenotonsillectomy is the first line of treatment for SDB and whilst this improves respiratory disturbance, it remains to be established whether neurocognitive gains also result. Methods: A total of 44 healthy snoring children aged 3–12 years awaiting adenotonsillectomy (SDB group), and 48 age and gender matched non-snoring controls from the general community, completed the study. All children underwent polysomnography and neurocognitive assessment at baseline and after a 6-month follow-up (after surgery in the snoring group). Our primary aim was to determine whether neurocognitive deficits in snoring children were significantly improved following adenotonsillectomy. Results: Wide ranging neurocognitive deficits were found at baseline in SDB children compared to controls, most notably a 10 point IQ difference (P<.001) and similar deficits in language and executive function. Whilst adenotonsillectomy improved respiratory parameters and snoring frequency at 6 months post surgery, neurocognitive performance did not improve relative to controls. Conclusion: Adenotonsillectomy successfully treated the respiratory effects of SDB in children. However, neurocognitive deficits did not improve 6-months post-operativelyMark J. Kohler, Kurt Lushington, Cameron J. van den Heuvel, James Martin, Yvonne Pamula and Declan Kenned

Relationship between vascular resistance and sympathetic nerve fiber density in arterial vessels in children with sleep disordered breathing

Sleep disordered breathing in children is associated with increased blood flow velocity and sympathetic overactivity. Sympathetic overactivity results in peripheral vasoconstriction and reduced systemic vascular compliance, which increases blood flow velocity during systole. Augmented blood flow velocity is recognized to promote vascular remodeling. Importantly, increased vascular sympathetic nerve fiber density and innervation in early life plays a key role in the development of early-onset hypertension in animal models. Examination of sympathetic nerve fiber density of the tonsillar arteries in children undergoing adenotonsillectomy for Sleep disordered breathing will address this question in humans.Thirteen children scheduled for adenotonsillectomy to treat sleep disordered breathing underwent pupillometry, polysomnography, flow-mediated dilation, resting brachial artery blood flow velocity (velocity time integral), and platelet aggregation. The dorsal lingual artery (tonsil) was stained and immunofluorescence techniques used to determine sympathetic nerve fiber density. Sympathetic nerve fiber density was correlated with increased resting velocity time integral (r=0.63; P<0.05) and a lower Neuronal Pupillary Index (r=-0.71, P<0.01), as well as a slower mean pupillary constriction velocity (mean, r=-0.64; P<0.05). A faster resting velocity time integral was associated with a slower peak pupillary constriction velocity (r=-0.77; P<0.01) and higher platelet aggregation to collagen antigen (r=0.64; P<0.05). Slower mean and peak pupillary constriction velocity were associated with higher platelet aggregation scores (P<0.05; P<0.01, respectively).These results indicate that sympathetic activity is associated with change in both the function and structure of systemic vasculature in children with sleep disordered breathing.Anna Kontos, Kurt Lushington, James Martin, Quenten Schwarz, Ryan Green, Ben, David Wabnitz, Xiangjun Xu, Elke M. Sokoya, Scott Willoughby, Mathias Baumert, Antonio Ferrante, Melissa La Forgia, Declan Kenned

The role of psychosocial safety climate on flexible work from home digital job demands and work-life conflict

Due to the COVID-19 pandemic, the number of employees in flexible work from home has increased markedly along with a reliance on information communication technologies. This study investigated the role of an organisational factor, psychosocial safety climate (PSC; the climate for worker psychological health and safety), as an antecedent of these new kinds of demands (specifically work from home digital job demands) and their effect on work-life conflict. Data were gathered via an online survey of 2,177 employees from 37 Australian universities. Multilevel modelling showed that university level PSC to demands, y=−0.09, SE=0.03, p<0.01, and demands to worklife conflict, y=0.51, SE=0.19, p<0.05, relationships were significant. Supporting the antecedent theory, university level PSC was significantly indirectly related to work-life conflict via demands (LL −0.10 UL −0.01). Against expectations PSC did not moderate the demand to work-life conflict relationship. The results imply that targeting PSC could help prevent work from home digital job demands, and therefore, work-life conflict. Further research is needed on the role of digital job resources as flexible and hybrid work takes hold post COVID.Amy K. Parkin, Amy J. Zadow, Rachael E. Potter, Ali Afsharian, Maureen F. Dollard, Silvia Pignata, Arnold B. Bakker, And Kurt Lushingto

The inconsistent nature of heart rate variability during sleep in normal children and adolescents

Introduction: Cardiac function is modulated by multiple factors including exogenous (circadian rhythm) and endogenous (ultradian 90-110 min sleep cycle) factors. By evaluating heart rate variability (HRV) during sleep, we will better understand their influence on cardiac activity. The aim of this study was to evaluate HRV in the dark phase of the circadian rhythm during sleep in healthy children and adolescents. Methods: One 3 min segment of pre-sleep electrocardiography (EEG) and 3, 6 min segments of electrocardiography recorded during polysomnography from 75 healthy children and adolescents were sampled during progressive cycles of slow wave sleep (SWS1, SWS2, SWS3). Three, 3 min segments of rapid eye movement sleep (REM) were also assessed, with REM1 marked at the last REM period before awakening. Studies that recorded REM3 prior to SWS3 were used for assessment. HRV variables include the following time domain values: mean NN (average RR intervals over given time), SDNN (Standard Deviation of RR intervals), and RMSSD (root Mean Square of beat-to-beat Differences). Frequency domain values include: low frequency (LF), high frequency (HF), and LF:HF. Results: Mixed linear effects model analysis revealed a significant difference in time and frequency domain values between sleep cycles and stages. Mean NN was lowest (highest heart rate) during pre-sleep then significantly increased across SWS1-3. Mean NN in SWS1 was similar to all REM periods which was significantly lower than both SWS2 and SWS3. SDNN remained at pre-sleep levels until SWS3, and then significantly increased in REM1&2. There was a large drop in LF from pre-sleep to SWS1. As cycles progressed through the night, LF remains lower than awake but increases to awake like levels by REM2. RMSSD and HF were lowest in pre-sleep and increased significantly by SWS1 and remain high and stable across stages and cycles except during the REM3 period where RMSSD decreased. Conclusion: Our results demonstrate that there are considerable changes in the spectral analysis of cardiac function occurring during different sleep stages and between sleep cycles across the night. Hence, time of night and sleep stage need to be considered when reporting any HRV differences.Anna Kontos, Mathias Baumert, Kurt Lushington, Declan Kennedy, Mark Kohler, Diana Cicua-Navarro, Yvonne Pamula, and James Marti

Oxadiazole-Based Cell Permeable Macrocyclic Transition State Inhibitors of Norovirus 2CL Protease

Human noroviruses are the primary causative agents of acute gastroenteritis and a pressing public health burden worldwide. There are currently no vaccines or small molecule therapeutics available for the treatment or prophylaxis of norovirus infections. Norovirus 3CL protease plays a vital role in viral replication by generating structural and nonstructural proteins via the cleavage of the viral polyprotein. Thus, molecules that inhibit the viral protease may have potential therapeutic value. We describe herein the structure-based design, synthesis, and in vitro and cell-based evaluation of the first class of oxadiazole-based, permeable macrocyclic inhibitors of norovirus 3CL protease