bluuebunny/crossref_metadata_2025_split huggingface dataset:
0029 The Effect of BMAL1 Expression on Autophagy Activity in Astrocytes
Authors: Campbell Connor 
Published: May 2023

Abstract

Introduction
Circadian rhythm disruption is an established symptom of neurodegenerative disease, however, there is mounting evidence that circadian systems drive early pathogenesis. The core circadian clock gene, BMAL1, mediates daily oscillations in transcription for homeostatic processes. Furthermore, the deletion of BMAL1 renders tissue transcriptionally arrhythmic and influences non-circadian genes, which causes reactive astrogliosis, oxidative stress, and neuronal injury in the brain. We have recently observed in-vitro that BMAL1 knockout astrocytes exhibit increases in the pH-sensitive lysosomal dye lysotracker. This suggests that the clock potentially modulates an even broader array of cellular processes, like autophagy, which maintains cellular homeostasis by delivering proteins to lysosomes for degradation. Given that deficits in the clearance of stable protein aggregates is characteristic of many neurodegenerative disorders, the manipulation of autophagic machinery displays therapeutic potential. Therefore, the purpose of this project is to evaluate whether autophagy activity in astrocytes is regulated rhythmically by circadian clocks or through non-rhythmic genes linked to BMAL1 expression.

Methods
Through employing the fluorescent (RFP)-EGFP-LC3 reporter, we can detect differential organelle pH values to reveal the autophagy dynamics. Specifically, the RFP:EGFP signal ratio represents the progression from the autophagosome to the acidic autolysosome, thereby quantitatively illustrating the protein degradation arising from autophagy machinery.

Results
When comparing astrocyte-specific BMAL1 knockout mice to the wildtype littermates, there are significant increases for EGFP and RFP channels within the white matter. Furthermore, the greater RFP:EGFP value exhibits upregulated protein degradation, which validates that BMAL1 deletion can modulate autophagy activity. Upon establishing the baseline fluorescence for wildtypes across the 24-hour cycle, the EGFP and RFP signals suggested rhythmic activity for the light-stimulated groups. Nevertheless, the insignificant sinusoidal patterns among the dark-only counterparts reduces the probability that circadian clocks regulate autophagy activity.

Conclusion
The effect of BMAL1 deletion on autophagosomes in white matter tissue likely originates from other glial cell types that are uniquely susceptible to dysfunction in non-rhythmic pathways related to BMAL1 expression in astrocytes. Ultimately, investigating how BMAL1 protects against neurodegeneration will reveal therapeutic approaches for manipulating the autophagy machinery to promote pathology clearance, along with emphasizing the importance for maintaining sleeping patterns.

Support (if any)
0031 Whole genome sequence analyses for Excessive Daytime Sleepiness in the NHLBI TOPMed Program
Authors: Zhang Yiyan , Kurniansyah Nuzulul , Nagarajan Pavithra , Chen Han , Purcell Shaun , Saxena Richa , Zhu Xiaofeng , Cade Brian , Sofer Tamar , Redline Susan , Wang Heming , Zhang Yiyan 
Published: May 2023

Abstract

Introduction
Excessive daytime sleepiness is associated with multiple sleep, cardiometabolic, and neuropsychiatric disorders. Previous genome-wide association studies (GWAS) of daytime sleepiness using a single question in European population revealed associations for multiple genes in central nervous pathways. However, findings are still limited and may not be generalizable to other populations. In this study, we performed the first whole-genome sequence (WGS) analyses for Epworth Sleepiness Scale (ESS) in the NHLBI Trans-Omics for Precision Medicine (TOPMed) program.

Methods
This study includes 15,201 individuals of diverse race and ethnic backgrounds from seven cohorts in the TOPMed. We performed GWAS of single common variants (MAF&gt;0.01) and gene-based burden tests of low-frequency and rare functional variants (loss of function and missense; MAF&lt; 0.05). We adjusted for age, sex, body mass index (BMI), study, race/ethnicity, and genetic relatedness using linear mixed effects models implemented in the GENESIS R package.

Results
This sample included 43.8% males with a mean age of 54.9 years and BMI 29.6kg/m2, of whom 21.3% were classified with excessive daytime sleepiness (ESS&gt;=10). In single variant test, we identified one novel genomic locus at rs60249969 (on CELF2) significantly associated with ESS (p-value=3.91x10-8). Suggestive significant associations were observed at 5 novel loci that overlapped with PDE7A/DNAJC5B, AHI1/PDE7B, KCNH7, F5, and FBXL17 (p&lt; 1x10-7). In gene-based burden test, we did not identify any gene significantly associated with the ESS after correcting for multiple comparisons (p&lt; 2x10-6). Suggestive significant evidence was observed at OR1A2 (consisting of 41 missense variants; p-value=1.65x10-5), an olfactory receptor gene differentially expressed in choroid plexus in the brain implicated in neurodegenerative diseases.

Conclusion
In our investigation of common and rare variant associations with excessive daytime sleepiness as assessed by the ESS, we identified one significant and several suggestive novel loci that mapped to genes highly expressed in brain tissues, which may have implications on sleep wake control system. Our next step will include replication analyses using independent imputed samples.

Support (if any)
R01HL153814 (to H.W.), NHLBI R35HL135818 (to S.R.).
0034 Genetic Variants for Obstructive Sleep Apnea Identified after Modeling Interactions with Daytime Sleepiness
Authors: Nagarajan Pavithra , Chen Han , Zhang Yiyan , Kurniansyah Nuzulul , Purcell Shaun , Saxena Richa , Zhu Xiaofeng , Cade Brian , Sofer Tamar , Redline Susan , Wang Heming ,   TOPMed Sleep Working Group
Published: May 2023

Abstract

Introduction
Obstructive sleep apnea (OSA) is a complex sleep disorder that presents with a range of symptoms, including excessive daytime sleepiness (EDS), postulated to represent a more severe subtype. Despite significant heritability and past GWASs, genetic mechanisms of the disorder remain unclear. Given that EDS often reflects chronic sleep insufficiency and a pro-inflammatory state, we reasoned it may interact with genetic variants to modify risk for OSA. We tested this hypothesis by investigating gene by sleepiness interaction analysis of OSA.

Methods
Whole-genome sequencing data of 11,619 individuals of diverse race and ethnic backgrounds from the NHLBI Trans-Omics for Precision Medicine program was used, with the outcome being Apnea-Hypopnea Index (AHI) and the exposure Epworth Sleepiness Scale (&gt;10: EDS, &lt;=10: non-EDS). GENESIS R package was used to perform 2-stage rank normalization, adjusting for age, sex, BMI, ancestral PCs, cohort, and genetic relatedness, and rescaling residuals to a unit variance, separately in each study/ancestry group. GEM software was used to perform gene-EDS interaction analyses, including 1 df tests of marginal SNP effect and interaction effect of SNPxEDS on AHI, respectively, and 2 df test of joint significance of both. Robust standard errors were used, with a significance threshold of p&lt; 5x10-8.

Results
The 1 df test of marginal SNP effect identified one novel locus (rs35370454) that mapped to IFRD1, whose overexpression has been associated with sleep restriction, and hypomethylation with narcolepsy. The 1 df test of interaction effect identified two novel loci (rs13118183, rs281851) that mapped to genes MARCHF1 and CCDC3. The 2 df joint test did not reveal additional novel loci. CCDC3 has shown to repress inflammatory activity of TNF-alpha, a cytokine postulated to be involved in sleep regulation. MARCHF1 has shown to inhibit cellular insulin sensitivity as well as promote NF-KB, with degree of activation positively correlating with OSA severity.

Conclusion
By modeling the modification effect of EDS on OSA we identified 3 novel loci. This approach may be useful in understanding the genetic factors that vary across OSA subtypes. For next steps, we seek to conduct replication analysis using independent imputed samples.

Support (if any)
NHLBI, R01HL153814 (H.W.), R35HL135818 (S.R.).
0036 ARC Genotype Modulates REM EEG Spectral Power Following Total Sleep Deprivation
Authors: Satterfield Brieann , Finlay Myles , Skeiky Lillian , Fluke Sofia , Van Dongen Hans 
Published: May 2023

Abstract

Introduction
EEG spectral power in the alpha range is indicative of a wake-like state, with alpha power typically high during wakefulness and reduced during sleep. We previously reported that a single nucleotide polymorphism (SNP) of the activity-regulated cytoskeleton associated protein (ARC) gene modulates non-REM theta and alpha spectral power. Here we sought to determine whether ARC genotype is also associated with phenotypic differences in EEG spectral power during REM sleep.

Methods
43 healthy adults (27.6±4.8y; 23 females) participated in one of two in-laboratory studies. Each participant had a 10h baseline sleep opportunity (22:00–08:00), 38h TSD, and 10h recovery sleep opportunity (22:00–08:00). Sleep periods were recorded polysomnographically and visually scored according to AASM criteria. Genomic DNA was assayed for the ARC c.*742 + 58C&gt;T non-coding SNP, rs35900184. Log-transformed EEG spectral power (C3-M3 derivation) for REM sleep over 0.2 Hz frequency bins in each of four frequency bands – delta (0.8–4.0 Hz), theta (4.2–8.0 Hz), alpha (8.2–12.0 Hz), and beta (12.2–16.0 Hz) – was analyzed by band using mixed-effects ANOVA with fixed effects for ARC genotype, night (baseline, recovery), frequency bin, and their interactions. Analyses included study and age as covariates and a random effect over subjects on the intercept.

Results
The genotype distribution in this sample was 28 C/C homozygotes, 10 C/T heterozygotes, and 5 T/T homozygotes. There was a significant genotype by night interaction in the alpha band (F2,1560=23.80, p&lt; 0.001). Compared to baseline sleep, T/T homozygotes had 13.0% more alpha power during post-TSD recovery sleep, whereas C/C homozygotes had 1.2% less alpha power and C/T heterozygotes had 3.2% less alpha power. This differential TSD effect for the ARC genotypes was not seen in the other spectral bands.

Conclusion
Our results show that ARC genotype mediates the REM sleep EEG response to TSD, with T/T homozygotes displaying a pronounced increase in REM alpha power following sleep deprivation. The ARC SNP has been associated with schizophrenia, a psychiatric disorder with known sleep disturbances. As such, the ARC-mediated increase in REM EEG alpha power for T/T homozygotes might be a marker of a psychosis-like predisposition.

Support (if any)
ONR N00014-13-1-0302; NIH R21CA167691; USAMRDC W81XWH-18-1-0100; ARO W911NF2210223
0049 Orexin 2 receptor agonist activates pre-Bötzinger complex neurons, phrenic motoneurons and the diaphragm in rodents
Authors: Kimura Haruhide , Yamada Ryuji 
Published: May 2023

Abstract

Introduction
Neurons in the pre-Bötzinger complex are critical for the generation of inspiratory rhythm and regulation of activity of phrenic motoneurons, which control the activity of the diaphragm. Dysregulation of this neuronal network and resulting dysfunction of the diaphragm is associated with central sleep apnea (CSA). Orexins by stimulating both orexin 1 receptor (OX1R) and/or orexin 2 receptor (OX2R) can activate these neurons and the diaphragm. In this study, we assessed effects of OX2R-selective agonists on the activity of neurons in the pre-Bötzinger complex, phrenic motoneurons, and the diaphragm.

Methods
OX2R-selective agonists danavorexton (TAK-925) and OX-201 (a tool compound with longer plasma half-life than danavorexton in rodents) were used. OX2R and OX1R agonistic activities were examined by calcium mobilization assay in hOX2R/CHO-K1 cells and hOX1R/CHO-K1 cells, respectively. Activity of neurons in the pre-Bötzinger complex and phrenic motoneurons was investigated by electrophysiological recording in rat tissues. Activity of the diaphragm was evaluated by electromyogram recording in anesthetized rats. Respiratory activity was evaluated by whole-body plethysmography recording in mice.

Results
Danavorexton and OX-201 showed potent OX2R agonistic activity with 50% effective concentration (EC50) values of 5.5 nM and 8.0 nM, respectively. Danavorexton and OX-201 had &gt;5,000-fold and 1,000-fold OX2R selectivity over OX1R, respectively. In in vitro electrophysiological analyses, danavorexton and OX-201 increased the burst frequency of neurons in the pre-Bötzinger complex (EC50: 300 nM and 760 nM, respectively) and phrenic motoneurons (EC50: 1.6 µM and not determined, respectively). Intravenous administration of OX-201 at 1 and 3 mg/kg increased burst frequency of the diaphragm in anesthetized rats and oral administration at 3 mg/kg increased respiratory activity in conscious mice.

Conclusion
OX2R-selective agonists may enhance respiratory function via activation of the diaphragm through stimulation of neurons in the pre-Bötzinger complex and phrenic motoneurons. OX2R agonists may have therapeutic potential in patients with CSA if enhancement of respiratory function by OX2R agonists can be observed at non-arousal concentrations. Further preclinical and clinical studies are worth conducting in patients with CSA.

Support (if any)
This work was conducted by Takeda Pharmaceutical Company Limited.
0053 Circadian Regulation in the Social Brain: How Sleep Deprivation Compromises Empathy
Authors: Turnbull Mark , Malby Connor , Jensen Emily , Sharif Fatima , Donninger Jenna , Goodall Stuart , Ansdell Paul , Santhi Nayantara 
Published: May 2023

Abstract

Introduction
The interaction between the circadian clock and sleep drive generates a rhythm of deterioration and recovery in cognition over wake and sleep, respectively. In modern society, our sleep is often disrupted due to long and unsociable work hours. Emerging evidence suggests that this negatively impacts our social interactions, but the physiological mechanisms remain unclear. Our perceptions of other people’s mental states dominate interpersonal interactions, and profoundly impact our lives. This study examined how sleep deprivation impacts our perceptions of another’s mental state (a cognitive domain known as Theory of Mind: ToM).

Methods
21 young healthy adults completed the study (11 females: mean age +/-SD =22.09 +/- 3.59, 10 males: mean age +/- SD =23 + 4.13). Over a 12-hour overnight wakefulness period, we examined changes in ToM every two hours with the Reading in the Mind’s Eye (RMIE) task. It consists of 36 images, each a pair of eyes representing an emotion, categorized as Easy or Difficult and as positive, negative, and neutral (valence). We measured accuracy based on a 4-forced alternative response. Subjective sleepiness was measured every two hours with the Karolinska Sleepiness Scale (KSS).

Results
Our analysis revealed a significant effect of wakefulness on accuracy (p &lt; 0.0001), such that it declined precipitously 4 hours into the protocol (coinciding with midnight). Accuracy was significantly better (p&lt; 0.01) for Easy stimuli than on Difficult stimuli, but accuracy on both declined significantly with wakefulness. A similar result was seen with valence (p&lt; 0.0001), with Positive stimuli (74.5% +/- 1.8%) showing a better accuracy (mean +/- 1SE) than negative (57.4% +/- 1.9%) and neutral (58.2% +/- 1.7%) ones. But accuracy on all three declined with wakefulness (Positive: 84% -72.4%; Negative:61.2% - 58.5; Neutral: 64.2% - 59.9%). Sleepiness increased significantly overnight (p&lt; 0.0001). Furthermore, there was a significant correlation (correlation: 0.5; Fisher’s z test: p = 0.03) between the change sleepiness and RMIE task accuracy.

Conclusion
These findings are one of first descriptions of the circadian and sleep regulation in Theory of Mind, our ability to empathize. They have significant scientific and clinical implications.

Support (if any)
British Academy/Leverhume Small Research Grant to Nayantara Santhi.
0056 Sleep Characteristics Predict Metacognitive Functioning Above-and-Beyond Age, Education, and Mood
Authors: Nielson Spencer , Dautovich Natalie , Dzierzewski Joseph 
Published: May 2023

Abstract

Introduction
Metacognition, also-known-as subjective cognitive functioning, is an important predictor of cognitive decline and previous work has identified age, education, and mental health symptoms as important predictors. Sleep is essential for optimal neurocognitive functioning; as such, sleep may also play an important role in determining estimates of metacognition. However, it is currently unknown if sleep is associated with metacognition above-and-beyond known predictors. This study aimed to investigate whether sleep characteristics, including insomnia symptoms, global sleep health, and sleep regularity, were associated with metacognitive functioning above-and-beyond know predictors of age, education, and mood.

Methods
Participants (N=3284) included adults (Mage=42.7 years,48.5% female) who completed an online study investigating sleep and health across the lifespan. Participants self-reported their age and education and completed various questionnaires including the 6-item PROMIS Cognitive Function questionnaire, the Patient Health Questionnaire-4 (PHQ-4), the Insomnia Severity Index (ISI), the RU-SATED sleep health questionnaire, and the Sleep Regularity Questionnaire (SRQ). Stepwise regression models were used to investigate whether ISI, RU-SATED, and SRQ scores predicted PROMIS Cognitive Function scores after accounting for age, education, and PHQ-4 scores.

Results
In Step 1 of the model, age and education significantly predicted metacognitive functioning (β=.146, t=8.44, p&lt;.001; β=.086, t=4.97, p&lt;.012). In Step 2, PHQ-4 scores and education were significant while age was no longer significant (β=-.589, t=-40.56, p&lt;.001; β=.03, t=2.10, p=.036). In Step 3, age, education, and RU-SATED scores were not significant predictors while scores on the PHQ-4, ISI, and SRQ were significant predictors of metacognitive functioning (β=-.346, t=-21.93, p&lt;.001; β=-.38, t=-20.20, p&lt;.001; β=.052, t=3.20, p=.001). Step 3 accounted for a significant increase in variance explained (∆R2=.121, F=497.07, p&lt;.001).

Conclusion
Sleep characteristics, including insomnia symptoms and sleep regularity, are associated with metacognition above-and-beyond known predictors including age, education, and mood. Sleep characteristics may be an important part of estimates of metacognition. Moreover, because sleep is a modifiable risk factor with effective treatments, it may have potential as a treatment target for cognitive decline. Further research is needed to investigate whether the sleep-metacognitive functioning differs between common demographic groups and whether sleep disturbances predate declines in metacognitive functioning or vice versa.

Support (if any)
National Institute on Aging: Award K23AG049955 (PI: Dzierzewski).
0057 The Impact of Cortical Oxygenation During Sleep-Disordered Breathing on Cognition
Authors: Kawai Makoto , O'hara Ruth 
Published: May 2023

Abstract

Introduction
Untreated sleep-disordered breathing (SDB) has been reported as a common risk for dementia. However, the association between current SDB parameters (i.e., AHI) and cognition is not straightforward. To examine the impact of cortical oxygenation during SDB on cognition in older adults, we measured the coherence of oxyHb and SpO2 during SDB, in which a higher level can represent less protection against systemic hypoxia, is associated with cognition in older adults.

Methods
Thirty-eight community-dwelling, healthy older adults without dementia (20 women) were recruited. The mean and standard deviation (SD) of age was 72.6±6.4years. All participants underwent comprehensive neuropsychiatric evaluation of short and long-term verbal memory(Wechsler Memory Scale & Rey Auditory Verbal Learning Test), Executive Functioning (Delis-Kaplan Executive Function System), verbal naming abilities (Boston Naming Test), and visuo-spatial ability (Judgment of Line Orientation). We performed a simultaneous PSG and NIRS recording overnight at the participants’ houses. We measured the mean max coherence of oxyHb and SpO2 and analyzed its correlation to cognition.

Results
The mean and SD of total sleep time, N1, N2, N3, and REM were 392.8±71.8 min, 65.5±60.3min, 210.7±68.5min, 53.1±30.9min, and 63.5±25.4 min. The mean and SD of AHI were 21±17.4 events/hour. The mean and SD of the max coherence ratio were 0.78±0.10. Linear regression analysis found higher coherence of oxyHb and SpO2 to be significantly correlated, after Bonferroni Correction, with a poorer score on the age-corrected BNT score (t = -3.174, p = .003), covaried for gender and education.

Conclusion
Higher coherence of oxyHb and SpO2 during SDB may predict poorer verbal naming abilities in older adult

Support (if any)
National Instutite on Aging
0059 Acoustic enhancement of sleep slow oscillations nested to spindles relative to delta waves improves memory consolidation
Authors: Grimaldi Daniela , Mikutta Christian , Reid Kathryn , Papalambros Nelly , Malkani Roneil , Abbott Sabra , Paller Ken , Zee Phyllis 
Published: May 2023

Abstract

Introduction
The nesting of electroencephalographic (EEG) sleep slow oscillations (SOs) to spindles has been shown to be important for sleep-dependent memory consolidation. However, recent evidence indicates that a higher proportion of SOs nested to spindles, relative to δ waves, might be even more critical for sleep-dependent memory consolidation. Acoustic stimulation during slow wave sleep has been shown to be effective in improving memory consolidation. Here, we examined the contribution of SOs nested to spindles relative to δ waves on sleep-dependent declarative memory consolidation associated with acoustic stimulation.

Methods
Twenty subjects (18-35 years, 75% females) participated in a randomized cross-over study. At each visit participants received either stimulation (stim) or sham following an adaption night. Stim occurred in blocks of 5 pulses (ON intervals) followed by a period of equal length with no stimulation (OFF intervals). Participants learned 40 Arabic-English word pairs and were tested before sleep and after sleep in the morning and again in the afternoon. Detection of SOs (&lt; 2 Hz), δ waves (2-4 Hz), spindles (11-16Hz), and the ratio (%) of spindles nested to SO over δ waves (SO/δ Nesting Index) were calculated during ON intervals for stim and sham conditions.

Results
Overnight mean (SD) percentage change in word recall between conditions was similar in the morning (stim 6(3)%, sham 4(6)%, p=0.68), but was higher in the afternoon in stim compared to the sham condition (stim 10(4)%, sham 4(6)%, p=0.02). The SO/δ Nesting Index was higher in stim compared to the sham condition (stim 21(13)%, sham 13(10%), p=0.004). Within-subject improvement from sham to stim condition in afternoon memory was associated with a greater change in SO/δ Nesting Index (R=0.63, p=0.03), this association was not observed for spindles nested to SOs (R=0.33, p=0.202) or spindles nested to δ waves (R=-0.18, p=0.811).

Conclusion
Enhancement of memory consolidation with acoustic stimulation may be dependent on its ability to increase SOs nested to spindles relative to δ waves. Dynamic changes in the relationships between SOs, δ waves and spindles can help inform novel EEG-derived markers and targets to enhance sleep-dependent memory consolidation.

Support (if any)
DARPA award W911NF-16- 2-0021