Genetics of circadian rhythms and sleep in human health and disease

Pleiotropic effects of APOE variants on a sleep-based adult epidemiological cohort

OBJECTIVES

Phenome Wide Association study (PheWAS) approach was applied in a sleep-based adult epidemiological cohort to address pleiotropic effects of APOE variants in sleep patterns.

METHODS

PheWAS analysis was performed on the São Paulo Epidemiologic Sleep Study (EPISONO), an adult epidemiological sample (1042 individuals) submitted to objective and subjective sleep evaluations, laboratory tests, clinical scales, anthropomorphic measurements and sociodemographic inquiries (1182 traits per individual). We determined APOE alleles using SNP-array and qPCR data. PheWAS was performed with an additive genetic model for the variant rs7412, using age, age2, sex, principal components, socioeconomic classification and body mass index as covariates. Validation analysis was performed for combinations of APOE full haplotypes (ε3ε3, ε2ε2, ε4ε4, ε2ε3, ε2ε4, and ε3ε4).

RESULTS

When all covariates were applied, nominal associations (p < 0.05 in PheWAS) between the rs7412 genotype and 5 continuous traits were identified and confirmed by non-parametric tests: LDL and total cholesterol blood concentrations, Morningness-Eveningness Questionnaire (MEQ) score, power of gamma and beta electroencephalographic (EEG) frequency bands in N1 and N3, respectively. The association with LDL levels remained significant after Bonferroni correction. All these 5 traits were significantly associated at nominal level with at least 1 of the APOE haplotype combinations. Lower LDL and cholesterol levels were associated with ε2ε3 genotype, higher MEQ scores were observed in ε2ε2 individuals, higher power of gamma waves in N1 was associated with ε2ε2, ε2ε3 and ε4ε4 (with indication of putative dosage effect for ε2 haplotype), and higher power of beta waves in N3 was associated with the ε2ε3 genotype.

CONCLUSIONS

Extensive APOE associations with lipid metabolism were replicated in an admixed cohort, despite sample size limitations. Suggestive associations of APOE genotype with diurnal preference scores and variables derived from sleep EEG spectral analysis present preliminary evidence of the effect of these variants over sleep patterns and individual differences in circadian typology.

Differential benefits of 12-week morning vs. evening aerobic exercise on sleep and cardiometabolic health: a randomized controlled trial

Modern life and rising stress have contributed to increased sleep disorders and metabolic and cardiovascular diseases. While exercise is known to be an important health intervention, the optimal timing for its effectiveness remains uncertain. This study aims to investigate the effects of a 12-week timed exercise program on sleep, lipid profiles, and vascular function. Fifty-eight sedentary males were divided into three groups: morning exercise (ME) at 6-8 a.m., evening exercise (EE) at 6-8 p.m., and control group (CON) without exercise. The 12-week intervention involved moderate-intensity aerobic exercise (≥ 150 min/week). Sleep was assessed using the Munich ChronoType Questionnaire (MCTQ) and Dim Light Melatonin Onset (DLMO). Metabolic indicators were assessed through body composition and blood biochemical tests. Ultrasound imaging was performed to evaluate hemodynamics at the common carotid artery. Both exercise groups reduced body fat after 12-week exercises, with ME showing significant reductions as early as week 4. Total cholesterol and triglycerides in ME also decreased. Shortened sleep latency was observed in both exercise groups, with DLMO and sleep advanced in ME. Although both exercise groups showed decreased stiffness and increased wall shear stress, EE demonstrated greater enhancements in blood flow rate, center-line velocity, carotid artery dilation and lowering systolic blood pressure. A 12-week aerobic exercise significantly improves physical health in sedentary adults. Morning exercise (6-8 a.m.) is particularly effective for rapid body fat reduction, lowering plasma cholesterol and triglycerides, and advancing sleep-wake cycle. Evening exercise (6-8 p.m.) is more effective for enhancing vascular function.Trial registration: Chinese Clinical Trial Registry, ChiCTR2400094208, 18/12/2024.

Human genetic variation determines 24-hour rhythmic gene expression and disease risk

24-hour biological rhythms are essential to maintain physiological homeostasis. Disruption of these rhythms increases the risks of multiple diseases. Biological rhythms are known to have a genetic basis formed by core clock genes, but how individual genetic variation shapes the oscillating transcriptome and contributes to human chronophysiology and disease risk is largely unknown. Here, we mapped interactions between temporal gene expression and genotype to identify quantitative trait loci (QTLs) contributing to rhythmic gene expression. These newly identified QTLs were termed as rhythmic QTLs (rhyQTLs), which determine previously unappreciated rhythmic genes in human subpopulations with specific genotypes. Functionally, rhyQTLs and their associated rhythmic genes contribute extensively to essential chronophysiological processes, including bile acid and lipid metabolism. The identification of rhyQTLs sheds light on the genetic mechanisms of gene rhythmicity, offers mechanistic insights into variations in human disease risk, and enables precision chronotherapeutic approaches for patients.

Roles of circadian clocks in macrophage metabolism: implications in inflammation and metabolism of lipids, glucose, and amino acids

Macrophages are essential immune cells that play crucial roles in inflammation and tissue homeostasis and are important regulators of metabolic processes, such as the metabolism of glucose, lipids, and amino acids. The regulation of macrophage metabolism by circadian clock genes has been emphasized in many studies. Changes in metabolic profiles occurring after the perturbation of macrophage circadian cycles may underlie the etiology of several diseases. Specifically, chronic inflammatory disorders, such as atherosclerosis, diabetes, cardiovascular diseases, and liver dysfunction, are associated with poor macrophage metabolism. Developing treatment approaches that target metabolic and immunological ailments requires an understanding of the complex relationships among clock genes, disease etiology, and macrophage metabolism. This review explores the molecular mechanisms through which clock genes regulate lipid, amino acid, and glucose metabolism in macrophages and discusses their potential roles in the development and progression of metabolic disorders. The findings underscore the importance of maintaining circadian homeostasis in macrophage function as a promising avenue for therapeutic intervention in diseases involving metabolic dysregulation, given its key roles in inflammation and tissue homeostasis. Moreover, reviewing the therapeutic implications of circadian rhythm in macrophages can help minimize the side effects of treatment. Novel strategies may be beneficial in treating immune-related diseases caused by shifted and blunted circadian rhythms via light exposure, jet lag, seasonal changes, and shift work or disruption to the internal clock (such as stress or disease).

Regulation of circadian gene activity in fibroblasts from ADHD patients through Rosiglitazone: a pilot study

Attention-deficit/hyperactivity disorder (ADHD) is a frequently observed condition, with about 70% of individuals diagnosed with ADHD experiencing irregular sleep-wake patterns. Beyond the primary symptoms of ADHD, there is a significant overlap with sleep-related issues, indicating that disrupted sleep patterns may exacerbate ADHD symptoms. ADHD-related sleep problems can be traced to a delayed circadian rhythm and a later onset of melatonin production. Therefore, normalizing circadian rhythms has been proposed as a potential therapeutic target for psychiatric disorders. Recent animal studies have provided compelling evidence linking peroxisome proliferator-activated receptor gamma (PPARγ), a key regulator of energy metabolism, to the regulation of physiological and behavioral rhythms. In this study, we hypothesized that treating fibroblasts from ADHD patients, which exhibit disturbances in circadian rhythmicity that are replicated in peripheral fibroblasts, with rosiglitazone may restore their circadian rhythmicity to that of the controls. To this end, we used cultures of fibroblasts obtained from skin biopsy explants of ADHD patients and controls and investigated the temporal patterns of clock gene expression over a period of 24 h. We report that the administration of the PPARγ agonist, rosiglitazone significantly realigns the chronobiological patterns of ADHD patient samples and control groups by inducing phase shifts in the expression of the BMAL1, PER3, and CRY1 clock genes. Nevertheless, rosiglitazone showed limited impact on the amplitude and phase of CLOCK1, NPAS2, and PER1. No notable changes were observed in PER2 and PER3 gene expression. The data from cultured human dermal fibroblasts indicate that PPARγ-agonists may help regulate circadian molecular mechanisms. Given the shared genetic pathways between ADHD and obesity, future studies could investigate the potential of RSG as a treatment for circadian rhythm disorders, particularly in obese patients with ADHD.

Long-term variable photoperiod exposure impairs hippocampal synapse involving of the glutamate system and leads to memory deficits in male Wistar rats

Excessive artificial light at night can induce the human circadian misalignment, potentially impairing memory consolidation and the rhythms of hippocampal clock genes. To investigate the impact of circadian misalignment on hippocampal function, we measured various field excitatory postsynaptic potentials (fEPSP) and golgi staining in the CA1 and dentate gyrus (DG) regions in Wistar rats. Our findings revealed that circadian misalignment resulted in a leftward shift in the input-output (I-O) curve within the CA1 region, decreased long-term potentiation (LTP), multi-time interval paired-pulse ratio (PPR), as well as dendritic spines and complexity across both CA1 and DG regions. Additionally, magnetic resonance spectroscopy (MRS) showed that circadian misalignment downregulated glutamate-related neurotransmitters (Glu + Gln) in the hippocampus, contributing to impaired synaptic function. Furthermore, disruptions to glutamate receptor subunits due to circadian misalignment led to reduced expression of AMPA receptor and NMDA receptor subunits in the hippocampus. In summary, our results suggest that memory impairments resulting from circadian misalignment are associated with diminished functionality within the glutamatergic system; this includes reductions in both Glx levels and availability of glutamate receptor subunits-key factors contributing to compromised synaptic function within the hippocampus.

A novel method to separate circadian from non-circadian masking effects to enhance estimation of circadian timing and amplitude from core body temperature

STUDY OBJECTIVES

Circadian disruption contributes to adverse effects on sleep, performance, and health. One accepted method to track continuous daily changes in central circadian timing is to measure core body temperature (CBT), and establish daily, circadian-related CBT minimum time (Tmin). This method typically applies cosine-model fits to measured CBT data, which may not adequately account for substantial masking of circadian effects, and thus estimates of the circadian-related Tmin. This study introduced a novel physiology-grounded analytic approach to separate circadian from non-circadian effects on CBT, which we compared against traditional cosine-based methods.

METHODS

The dataset comprised 33 healthy participants (mean ± SD 32 ± 13 years) attending a 39-h in-laboratory study with an initial overnight sleep followed by an extended wake period. CBT data were collected at 30-s intervals via ingestible capsules. Our design captured CBT during both the baseline sleep period and during extended wake period (without sleep) and allowed us to model the influence of circadian and non-circadian effects of sleep, wake, and activity on CBT using physiology-guided generalized additive models.

RESULTS

Compared to the traditional cosine model, the new model exhibited superior fits to CBT (Pearson R 0.90 [95 %CI; [0.83-0.96] versus 0.81 [0.55-0.93]). The difference between estimated vs measured circadian Tmin, derived from the day without sleep, was better fit with our method (0.2 [-0.5,0.3] hours) versus previous methods (1.4 [1.1 to 1.7] hours).

CONCLUSIONS

This new method provides improved demasking of non-circadian influences compared to traditional cosine methods, including the removal of a sleep-related bias towards an earlier estimate of circadian Tmin.

Associations between plasma proteomic signatures and secondary sleep in older adults

Sleep disturbances are prevalent among elderly populations and are linked to various health complications. Understanding the underlying biological mechanisms contributing to sleep disorders is crucial for developing targeted interventions. In this study, we measured 355 plasma proteins in an elderly Japanese cohort (n=77) using a high-throughput proteomic platform. Additionally, we collected over 25,000 person-days of physical activity and sleep behavior data from wrist-worn wearable devices, focusing on total sleep time (TST) across 24 h and daytime sleep. Fragmented sleep was observed as one of the most prevalent sleep disturbances in this population. In protein expression analysis, we identified 9 protein biomarkers associated with increased secondary sleep TST, defined as additional sleep episodes outside of the main sleep episode within 24 h. These findings may suggest disruptions in circadian rhythms or underlying health conditions. Functional analysis revealed that biological processes related to inflammation play a significant role in regulating sleep behavior. Further analysis showed an association of 12 proteins with daytime sleep and 5 proteins with afternoon sleep. Overall, this study identified inflammatory biomarkers and biological processes associated with sleep behavior in the elderly, presenting promising opportunities for developing diagnostic tools and targeted clinical interventions.

Integrating cancer medicine into metabolic rhythms

Circadian rhythms are cell-intrinsic time-keeping mechanisms that allow organisms to adapt to 24-h environmental changes, ensuring coordinated physiological functions by aligning internal metabolic oscillations with external timing cues. Disruption of daily metabolic rhythms is associated with pathological events such as cancer development, yet the mechanisms by which perturbed metabolic rhythms contribute to tumorigenesis remain unclear. Herein we review how circadian clocks drive balanced rhythmic metabolism which in turn governs physiological functions of locomotor, immune, and neuroendocrine systems. Misaligned metabolic rhythms cause pathological states which further drive cancer initiation, progression, and metastasis. Restoring the balance of metabolic rhythms with chemical, hormonal, and behavioral interventions serves as a promising strategy for cancer therapy.

Association between accelerometer-measured irregular sleep duration and longitudinal changes in body mass index in older adults

BACKGROUND

Irregular sleep duration may disrupt circadian rhythms and contribute to metabolic, behavioral, and mood changes, potentially increasing the risk for obesity. However, quantitative data on the relationship between sleep duration irregularity and weight change are lacking.

METHODS

In this prospective study, we analyzed data from 10,572 participants (mean age: 63 years) in the UK Biobank who wore accelerometers for a week between 2013 and 2015 and had two body mass index (BMI; kg/m²) measurements on average 2.5 years apart. Irregular sleep duration was assessed by the within-person standard deviation (SD) of 7-night accelerometer-measured sleep duration.

RESULTS

Participants with sleep duration SD > 60 min versus ≤30 min had 0.24 kg/m2 (95% CI: 0.08, 0.40) higher BMI change (kg/m2), standardized to three-year intervals, and 80% (95% CI: 1.28, 2.52) higher risk for incident obesity, after adjusting for sociodemographic factors, shift work, and baseline BMI or follow-up period (p-nonlinearity <0.02 for both). These associations remained consistent after adjusting for lifestyle, comorbidities, and other sleep factors, including sleep duration. Age, sex, baseline BMI, and genetic predisposition to higher BMI (measured with a polygenic risk score) did not appear to modify the association.

CONCLUSIONS

Since irregular sleep duration is common, trials of interventions targeting sleep irregularity might lead to new public health strategies that tackle obesity.

Biorhythm-mimicking growth hormone patch

Timing dosing throughout the day impacts the therapeutic efficacy and side effects of medications. Thus, optimizing release profiles to synchronize drug concentrations with natural rhythms is critical for optimal therapeutic benefits. However, existing delivery systems are still inefficient in delivering drugs in a biorhythm-mimicking fashion. Here we describe a biorhythm-inspired growth hormone transdermal microneedle patch with multistage drug release that mimics the natural rhythm of human growth hormone secretion at night. Programmed drug release is achieved by combining a 'burst-release' module with several 'delayed-release' modules. Compared with the subcutaneous daily injections currently used in clinics, the patch exhibits enhanced efficacy in terms of longitudinal bone growth and bone quality, leading to bone length increases of ~10 mm and ~5 mm in healthy rats and growth hormone gene knockout mice, respectively. Our findings reveal that the biorhythm-mimicking release pattern significantly enhances growth hormone bioavailability and effectively regulates the growth-related biological process, thus boosting the secretion of insulin-like growth factor-1 and ultimately promoting bone growth.

Regulation of testosterone synthesis by circadian clock genes and its research progress in male diseases

ABSTRACT

The circadian clock is an important internal time regulatory system for a range of physiological and behavioral rhythms within living organisms. Testosterone, as one of the most critical sex hormones, is essential for the development of the reproductive system, maintenance of reproductive function, and the overall health of males. The secretion of testosterone in mammals is characterized by distinct circadian rhythms and is closely associated with the regulation of circadian clock genes. Here we review the central and peripheral regulatory mechanisms underlying the influence of circadian clock genes upon testosterone synthesis. We also examined the specific effects of these genes on the occurrence, development, and treatment of common male diseases, including late-onset hypogonadism, erectile dysfunction, male infertility, and prostate cancer.

Diurnal dynamics of the Zbtb14 protein in the ventral hippocampus are disrupted in epileptic mice

Our previous in silico data indicated an overrepresentation of the ZF5 motif in the promoters of genes in which circadian oscillations are altered in the ventral hippocampus in the pilocarpine model of temporal lobe epilepsy in mice. In this study, we test the hypothesis that the Zbtb14 protein oscillates in the hippocampus in a diurnal manner and that this oscillation is disrupted by epilepsy. We found that Zbtb14 immunostaining is present in the cytoplasm and cell nuclei. Western blot data indicate that the cytoplasmic and nuclear levels of Zbtb14 protein oscillate, but the phase is shifted. The densities of the Zbtb14-immunopositive cells express diurnal dynamics in the ventral hilus and CA3 but not in the dorsal hilus and CA3, or the somatosensory cortex. In the pilocarpine model of epilepsy, an increase in the level of Zbtb14 protein was found at 11 PM but not at 3 PM compared to controls. Finally, in silico analysis revealed the presence of the ZF5 motif in the promoters of 21 out of 24 genes down-regulated by epileptiform discharges in vitro, many of which are involved in neuronal plasticity. Our data suggest that Zbtb14 may be involved in the diurnal dynamic of seizure regulation or brain response to seizure rhythmicity.

Monitoring Sleep Quality Through Low α-Band Activity in the Prefrontal Cortex Using a Portable Electroencephalogram Device: Longitudinal Study

BACKGROUND

The pursuit of sleep quality has become an important aspect of people's global quest for overall health. However, the objective neurobiological features corresponding to subjective perceptions of sleep quality remain poorly understood. Although previous studies have investigated the relationship between electroencephalogram (EEG) and sleep, the lack of longitudinal follow-up studies raises doubts about the reproducibility of their findings.

OBJECTIVE

Currently, there is a gap in research regarding the stable associations between EEG data and sleep quality assessed through multiple data collection sessions, which could help identify potential neurobiological targets related to sleep quality.

METHODS

In this study, we used a portable EEG device to collect resting-state prefrontal cortex EEG data over a 3-month follow-up period from 42 participants (27 in the first month, 25 in the second month, and 40 in the third month). Each month, participants' sleep quality was assessed using the Pittsburgh Sleep Quality Index (PSQI) to estimate their recent sleep quality.

RESULTS

We found that there is a significant and consistent positive correlation between low α band activity in the prefrontal cortex and PSQI scores (r=0.45, P<.001). More importantly, this correlation remained consistent across all 3-month follow-up recordings (P<.05), regardless of whether we considered the same cohort or expanded the sample size. Furthermore, we discovered that the periodic component of the low α band primarily contributed to this significant association with PSQI.

CONCLUSIONS

These findings represent the first identification of a stable and reliable neurobiological target related to sleep quality through multiple follow-up sessions. Our results provide a solid foundation for future applications of portable EEG devices in monitoring sleep quality and screening for sleep disorders in a broad population.

Circadian rhythm, hypoxia, and cellular senescence: From molecular mechanisms to targeted strategies

Cellular senescence precipitates a decline in physiological activities and metabolic functions, often accompanied by heightened inflammatory responses, diminished immune function, and impaired tissue and organ performance. Despite extensive research, the mechanisms underpinning cellular senescence remain incompletely elucidated. Emerging evidence implicates circadian rhythm and hypoxia as pivotal factors in cellular senescence. Circadian proteins are central to the molecular mechanism governing circadian rhythm, which regulates homeostasis throughout the body. These proteins mediate responses to hypoxic stress and influence the progression of cellular senescence, with protein Brain and muscle arnt-like 1 (BMAL1 or Arntl) playing a prominent role. Hypoxia-inducible factor-1α (HIF-1α), a key regulator of oxygen homeostasis within the cellular microenvironment, orchestrates the transcription of genes involved in various physiological processes. HIF-1α not only impacts normal circadian rhythm functions but also can induce or inhibit cellular senescence. Notably, HIF-1α may aberrantly interact with BMAL1, forming the HIF-1α-BMAL1 heterodimer, which can instigate multiple physiological dysfunctions. This heterodimer is hypothesized to modulate cellular senescence by affecting the molecular mechanism of circadian rhythm and hypoxia signaling pathways. In this review, we elucidate the intricate relationships among circadian rhythm, hypoxia, and cellular senescence. We synthesize diverse evidence to discuss their underlying mechanisms and identify novel therapeutic targets to address cellular senescence. Additionally, we discuss current challenges and suggest potential directions for future research. This work aims to deepen our understanding of the interplay between circadian rhythm, hypoxia, and cellular senescence, ultimately facilitating the development of therapeutic strategies for aging and related diseases.

A good night's rest: A contemporary review of sleep and cardiovascular health

Sleep is increasingly recognized as a significant contributor to the development of cardiovascular disease (CVD). Recent American Heart Association guidelines incorporate sleep duration into the "Life's Essential Eight" framework of ideal cardiovascular health. This article will review the evidence relating sleep duration, regularity, and quality with all-cause and cardiovascular mortality, cardiometabolic syndrome, and coronary artery disease in adults. Short sleep duration is strongly associated with cardiovascular mortality, cardiometabolic risk factors, and coronary artery disease. Limited studies also suggest a possible U-shaped association, with long sleep duration also associated with greater cardiovascular risk. Sleep regularity has emerged as a strong and independent risk factor for CVD-related mortality, cardiometabolic syndrome, and subclinical atherosclerosis. Less is known about the impact of sleep quality on CVD, though a number of observational studies suggest a possible association with metabolic syndrome and subclinical atherosclerosis. This review provides an update of the literature on the cardiovascular impact of sleep for the everyday clinician and highlights gaps in knowledge that warrant future research.

Depression in High-Risk Offspring: The Mediating Role of Sleep Problems

Parental depression is associated with offspring depression and sleep problems are prospectively associated with the development of depression. However, little work has examined sleep problems in the offspring of depressed parents and whether these problems partially account for the association between parent and offspring depression. This longitudinal study examined the indirect effect of sleep problems on the association between parent psychopathology and offspring depression in a sample of 10,953 10 to 12-year-old children participating in the Adolescent Brain and Cognitive Development (ABCD) study. Controlling for age, sex, and other forms of parent psychopathology, we found significant indirect effects of parent to offspring depression through parent and youth reports of youth insomnia and hypersomnia. We also found indirect effects of parent history of anxiety and drug use problems to offspring depression through insomnia, and indirect effects of parent history of anxiety, drug use problems, and alcohol use problems to offspring depression through hypersomnia. Our findings show that sleep may be a mechanism of the transmission of parent depression, anxiety, drug use problems, and alcohol use problems to offspring depression. Mitigating sleep problems represents a potential avenue for preventative interventions in youth with a heightened susceptibility to depression.

Relationship Between Sleep Disturbances and In Vitro Fertilization Outcomes in Infertile Women: A Systematic Review and Meta-Analysis

BACKGROUND

In vitro fertilization (IVF) has been acknowledged as the primary assisted reproductive technique for fertilizing oocytes outside the female reproductive system. Sleep disorders are likely to affect infertility and its treatment. The present study was to investigate the relationship between sleep disturbances and IVF outcomes in infertile women.

METHODS

Databases, including PubMed, Embase, Cochrane Library, ProQuest, and Web of Science, were searched for the relevant articles published up to September 2023. The Newcastle-Ottawa Scale was used to assess the methodological quality of the included studies. Moreover, the random and fixed effects models using the STATA (v.11) software program presented the odds ratio with a 95% confidence interval (CI). Ultimately, a funnel plot was recruited to examine the sensitivity analysis.

RESULTS

During the initial search, 426 articles were retrieved, and ultimately, nine studies remained for systematic review, and among them, four studies entered into the meta-analysis (two cohort and two cross-sectional studies). According to the fixed effects model of the cross-sectional studies, the association between sleep quality and pregnancy rate was not confirmed (OR = 0.94; 95% CI = 0.81-1.07). Regarding the fixed effects model of included cohort studies, the results indicated an association between sleep quality and the pregnancy rate (OR = 1.08; 95% CI = 1.03-1.14). According to the random effects model of the cross-sectional studies, there was no significant association between sleep quality and pregnancy rate (OR = 0.82; 95% CI = 0.37-1.26). Regarding the random effect analysis of included cohort studies, the results indicated an association between sleep quality and the pregnancy rate (OR = 1.08; 95% CI = 1.03-1.14). Based on the total fixed effect analysis of the cross-sectional and cohort studies, the results also showed a significant association between sleep quality and pregnancy rate among infertile women (OR = 1.06; 95% CI = 1.01-1.11). In contrast, according to the random effect of the total studies, this association was not confirmed (OR = 1.02; 95% CI = 0.90-1.14).

CONCLUSION

Although the meta-analysis of the cohort studies showed a significant association between sleep quality and IVF outcomes, such as pregnancy rate, due to the novelty of the subject, more studies have not been published, and this study is considered a preliminary meta-analysis. Therefore, more studies with a strong methodology need to assess the relationship between sleep disorders and IVF outcomes.

Are humans facing a sleep epidemic or enlightenment? Large-scale, industrial societies exhibit long, efficient sleep yet weak circadian function

The Centers for Disease Control and Prevention declared sleep-related problems to be a public health epidemic. With the advent of biometric sleep tracking technology taking the sleep lab into the field, the study of human sleep is now global, and these new datasets show contrasting findings. Previous reports suggest sleep in small-scale, non-industrial societies to be short and fragmented yet characterized by greater circadian rhythmicity. However, the role of circadian rhythm indicators in understanding global variations in human sleep patterns remains unclear. We examine population-level sleep studies (n = 54) using polysomnography and actigraphy to test the sleep restriction epidemic hypothesis, which posits that labour demands and technological disruption in large-scale, industrial societies have reduced sleep duration. We used an actigraphy-generated circadian function index from both non-industrial and industrial societies (n = 866) to test the circadian mismatch hypothesis, which suggests that poor chronohygiene in regulated environments misaligns circadian rhythms in industrial societies. In rejection of the sleep restriction epidemic hypothesis, our results show that industrial societies experience the longest, most efficient sleep, whereas in support of the circadian mismatch hypothesis, sleepers in non-industrial societies are characterized by the greatest circadian function.

Calcineurin governs baseline and homeostatic regulations of non-rapid eye movement sleep in mice

Sleep need accumulates during waking and dissipates during sleep to maintain sleep homeostasis (process S). Besides the regulation of daily (baseline) sleep amount, homeostatic sleep regulation commonly refers to the universal phenomenon that sleep deprivation (SD) causes an increase of sleep need, hence, the amount and intensity of subsequent recovery sleep. The central regulators and signaling pathways that govern the baseline and homeostatic sleep regulations in mammals remain unclear. Here, we report that enhanced activity of calcineurin Aα (CNAα)-a catalytic subunit of calcineurin-in the mouse brain neurons sharply increases the amount (to ~17-h/d) and delta power-a measure of intensity-of non-rapid eye movement sleep (NREMS). Knockout of the regulatory (CnB1) or catalytic (CnAα and CnAβ) subunits of calcineurin diminishes the amount (to ~4-h/d) and delta power of baseline NREMS, but also nearly abrogates the homeostatic recovery NREMS following SD. Accordingly, mathematical modeling of process S reveals an inability to accumulate sleep need during spontaneous or forced wakefulness in calcineurin deficient mice. Moreover, calcineurin promotes baseline NREMS by antagonizing wake-promoting protein kinase A and, in part, by activating sleep-promoting kinase SIK3. Together, these results indicate that calcineurin is an important regulator of sleep need and governs both baseline and homeostatic regulations of NREMS in mice.

Genome-wide association analysis of composite sleep health scores in 413,904 individuals

Recent genome-wide association studies (GWASs) of several individual sleep traits have identified hundreds of genetic loci, suggesting diverse mechanisms. Moreover, sleep traits are moderately correlated, so together may provide a more complete picture of sleep health, while illuminating distinct domains. Here we construct novel sleep health scores (SHSs) incorporating five core self-report measures: sleep duration, insomnia symptoms, chronotype, snoring, and daytime sleepiness, using additive (SHS-ADD) and five principal components-based (SHS-PCs) approaches. GWASs of these six SHSs identify 28 significant novel loci adjusting for multiple testing on six traits (p < 8.3e-9), along with 341 previously reported loci (p < 5e-08). The heritability of the first three SHS-PCs equals or exceeds that of SHS-ADD (SNP-h2 = 0.094), while revealing sleep-domain-specific genetic discoveries. Significant loci enrich in multiple brain tissues and in metabolic and neuronal pathways. Post-GWAS analyses uncover novel genetic mechanisms underlying sleep health and reveal connections (including potential causal links) to behavioral, psychological, and cardiometabolic traits.

The role of circadian rhythm regulator PERs in oxidative stress, immunity, and cancer development

The complex interaction between circadian rhythms and physiological functions is essential for maintaining human health. At the heart of this interaction lies the PERIOD proteins (PERs), pivotal to the circadian clock, influencing the timing of physiological and behavioral processes and impacting oxidative stress, immune functionality, and tumorigenesis. PER1 orchestrates the cooperation of the enzyme GPX1, modulating mitochondrial dynamics in sync with daily rhythms and oxidative stress, thus regulating the mechanisms managing energy substrates. PERs in innate immune cells modulate the temporal patterns of NF-κB and TNF-α activities, as well as the response to LPS-induced toxic shock, initiating inflammatory responses that escalate into chronic inflammatory conditions. Crucially, PERs modulate cancer cell behaviors including proliferation, apoptosis, and migration by influencing the levels of cell cycle proteins and stimulating the expression of oncogenes c-Myc and MDM2. PER2/3, as antagonists in cancer stem cell biology, play important roles in differentiating cancer stem cells and in maintaining their stemness. Importantly, the expression of Pers serve as a significant factor for early cancer diagnosis and prognosis. This review delves into the link between circadian rhythm regulator PERs, disruptions in circadian rhythm, and oncogenesis. We examine the evidence that highlights how dysfunctions in PERs activities initiate cancer development, aid tumor growth, and modify cancer cell metabolism through pathways involved in oxidative stress and immune system. Comprehending these connections opens new pathways for the development of circadian rhythm-based therapeutic strategies, with the aims of boosting immune responses and enhancing cancer treatments.

Effects of sex, mating status, and genetic background on circadian behavior in Drosophila

Circadian rhythms play a crucial role in regulating behavior, physiology, and health. Sexual dimorphism, a widespread phenomenon across species, influences circadian behaviors. Additionally, post-mating physiological changes in females are known to modulate various behaviors, yet their effects on circadian rhythms remain underexplored. Here, using Drosophila melanogaster, a powerful model for studying circadian mechanisms, we systematically assessed the impact of sex and mating status on circadian behavior. We measured circadian period length and rhythm strength in virgin and mated males and females, including females mated to males lacking Sex Peptide (SP), a key mediator of post-mating changes. Across four wild-type and control strains, we found that males consistently exhibited shorter circadian periods than females, regardless of mating status, suggesting that circadian period length is a robust sexually dimorphic trait. In contrast, rhythm strength was influenced by the interaction between sex and mating status, with female mating generally reducing rhythm strength in the presence of SP signaling. Notably, genetic background significantly modulated these effects on rhythm strength. Our findings demonstrate that while circadian period length is a stable sex-specific trait, rhythm strength is shaped by a complex interplay between sex, mating status, and genetic background. This study advances our understanding of how sex and mating influence circadian rhythms in Drosophila and provides a foundation for future research into sexually dimorphic mechanisms underlying human diseases associated with circadian disruptions.

Circadian Rhythms and Lung Cancer in the Context of Aging: A Review of Current Evidence

Circadian rhythm is the internal homeostatic physiological clock that regulates the 24-hour sleep/wake cycle. This biological clock helps to adapt to environmental changes such as light, dark, temperature, and behaviors. Aging, on the other hand, is a process of physiological changes that results in a progressive decline in cells, tissues, and other vital systems of the body. Both aging and the circadian clock are highly interlinked phenomena with a bidirectional relationship. The process of aging leads to circadian disruptions while dysfunctional circadian rhythms promote age-related complications. Both processes involve diverse physiological, molecular, and cellular changes such as modifications in the DNA repair mechanisms, mechanisms, ROS generation, apoptosis, and cell proliferation. This review aims to examine the role of aging and circadian rhythms in the context of lung cancer. This will also review the existing literature on the role of circadian disruptions in the process of aging and vice versa. Various molecular pathways and genes such as BMAL1, SIRT1, HLF, and PER1 and their implications in aging, circadian rhythms, and lung cancer will also be discussed.

Clock-Sleep Communication

Rhythmicity is a characteristic feature of the inanimate universe. The organization of biological rhythms in time is an adaptation to the cyclical environmental changes brought on by the earth's rotation on its axis and around the sun. Circadian (L. Circa = "around or approximately"; diem = "a day") rhythms are biological responses to the geophysical light/dark (LD) cycle in which an organism adjusts to alterations in its internal physiology or external environment as a function of the time of day. Sleep has been considered a biological rhythm. Normal human sleep, an essential physiologic process, comprises two distinct phases: non-rapid eye movement (NREM) sleep and rapid eye movement (REM) sleep. A mature adult human's sleep/wake cycle displays a circadian rhythm with a ~24-hour cycle. According to the two-process model of sleep regulation, the human sleep/wake cycle is orchestrated by circadian and homeostatic processes. Sleep homeostasis (a sleep-dependent process) and circadian rhythm (a sleep-independent process) are two biological processes controlling the sleep/wake cycle. There are also ultradian (< 24-hour) rhythms, including the NREM-REM sleep cycle, which has been extensively studied. The clock and sleep genes both influence sleep. In this overview, we have reviewed the circadian genes and their role in regulating sleep. Besides, the gene expression and biological pathways associated with sleep and circadian rhythm-associated diseases also have been highlighted.

Siesta behavior and genetics interact to influence obesity risk

OBJECTIVE

In this cross-sectional study, we aim to investigate the interactions between obesity, siesta behavior, and the genetic propensity for siesta in a Mediterranean population, in whom siesta is deeply rooted.

METHODS

We applied a previously generated Siesta-Polygenic Score (PGS) in the ONTIME study (n = 1278). Siesta and other Mediterranean lifestyle behaviors were characterized using questionnaires. We further determined obesity grade. Secondarily, we measured weight loss during treatment as well as long-term weight-loss maintenance. Logistic regression analyses were performed to address our aim.

RESULTS

A total of 42.4% of the population usually took siesta. A significant genetic influence on siesta propensity was found, with a higher genetic predisposition linked to taking siesta more frequently (odds ratio [OR] = 1.17, 95% CI: 1.03-1.32; p = 0.015). Participants with a higher genetic propensity for siesta showed poorer dietary habits (p < 0.05). Among individuals with a high genetic propensity for siesta, we found that those who usually take siesta have lower odds of having obesity (p = 0.038) compared with those who do not. Similarly, in exploratory analysis, among individuals with a high genetic propensity for siesta, we found that those who usually take siesta have higher odds of weight-loss success (p = 0.007) compared with those who do not.    CONCLUSIONS: Considering the ongoing debate regarding whether siesta is beneficial or detrimental, our findings suggest that individual genetic predisposition to siesta might influence the association between siesta and health.

Evaluating causal associations of chronotype with pregnancy and perinatal outcomes and its interactions with insomnia and sleep duration: a mendelian randomization study

BACKGROUND

Observational studies suggested chronotype was associated with pregnancy and perinatal outcomes. Whether these associations are causal is unclear. Our aims are to use Mendelian randomization (MR) to explore (1) associations of evening preference with stillbirth, miscarriage, gestational diabetes, hypertensive disorders of pregnancy, perinatal depression, preterm birth and offspring birthweight; and (2) differences in associations of insomnia and sleep duration with those outcomes between chronotype preferences.

METHODS

We conducted two-sample MR using 105 genetic variants reported in a genome-wide association study (N = 248,100) to instrument for lifelong predisposition to evening- versus morning-preference. We generated variant-outcome associations in European ancestry women from UK Biobank (UKB, N = 176,897), Avon Longitudinal Study of Parents and Children (ALSPAC, N = 6826), Born in Bradford (BiB, N = 2940) and the Norwegian Mother, Father and Child Cohort Study (MoBa, N = 57,430), and extracted equivalent associations from FinnGen (N = 190,879). We used inverse variance weighted (IVW) as main analysis, with weighted median and MR-Egger as sensitivity analyses. Relying on the individual participant data from UKB, ALSPAC, BiB and MoBa, we also conducted IVW analyses of insomnia and sleep duration on the pregnancy and perinatal outcomes, stratified by genetically predicted chronotypes.

RESULTS

In IVW and sensitivity analyses, we did not find robust evidence of associations of chronotype with the outcomes. Insomnia was associated with a higher risk of preterm birth among evening preference women (odds ratio 1.61, 95% confidence interval: 1.17, 2.21), but not among morning preference women (odds ratio 0.87, 95% confidence interval: 0.64, 1.18), with an interaction P-value = 0.01. There was no evidence of interactions between insomnia and chronotype on other outcomes, or between sleep duration and chronotype on any outcomes.

CONCLUSIONS

This study raises the possibility of a higher risk of preterm birth among women with insomnia who also have an evening preference. Our findings warrant replications due to imprecise estimates.

A conserved role for ALG10/ALG10B and the N -glycosylation pathway in the sleep-epilepsy axis

Congenital disorders of glycosylation (CDG) comprise a class of inborn errors of metabolism resulting from pathogenic variants in genes coding for enzymes involved in the asparagine-linked glycosylation of proteins. Unexpectedly to date, no CDG has been described for ALG10 , encoding the alpha-1,2-glucosyltransferase catalyzing the final step of lipid-linked oligosaccharide biosynthesis. Genome-wide association studies (GWAS) of human traits in the UK Biobank revealed significant SNP associations with short sleep duration, reduced napping frequency, later sleep timing and evening diurnal preference as well as cardiac traits at a genomic locus containing a pair of paralogous enzymes ALG10 and ALG10B . Modeling Alg10 loss in Drosophila, we identify an essential role for the N -glycosylation pathway in maintaining appropriate neuronal firing activity, healthy sleep, preventing seizures, and cardiovascular homeostasis. We further confirm the broader relevance of neurological findings associated with Alg10 from humans and flies using zebrafish and nematodes and demonstrate conserved biochemical roles for N -glycosylation in Arabidopsis . We report a human subject homozygous for variants in both ALG10 and ALG10B arising from a consanguineous marriage, with epilepsy, brain atrophy, and sleep abnormalities as predicted by the fly phenotype. Quantitative glycoproteomic analysis in our Drosophila model identifies potential key molecular targets for neurological symptoms of CDGs.

Sleep medicine and chronobiology education among Brazilian medical students

Chronobiology and sleep medicine are pivotal disciplines for understanding human health. Additionally, the lack of training in medical schools exacerbates the underdiagnosis and undertreatment of sleep disorders. This study investigated the exposure of Brazilian medical students to chronobiology and sleep medicine during their undergraduate education and assessed their knowledge in these areas. The study was conducted between December 2021 and June 2022 through the administration of an online questionnaire (Google Forms) to medical students in the final two years of undergraduate studies. The questionnaire gathered student data (i.e., sex, age, and educational institution), research data (stage in the medical program with exposure to chronobiology or sleep medicine), and responses to a questionnaire on basic knowledge of sleep medicine and chronobiology (adapted from Assessing Sleep Knowledge in Medical Education - ASKME). A total of 240 students from medical schools in Brazil participated, 4.6% of whom reported no exposure to either subject, with exposure declining as students progressed through the curriculum. Only 3.7% reported specific disciplines covering these topics. Over half of the students encountered learning barriers, such as limited curriculum time. Despite these challenges, the accuracy rate in responses regarding chronobiology and sleep medicine was 79.75%, positively correlating with exposure level and knowledge retention. This study underscores the urgent need for enhanced education in sleep medicine and chronobiology within Brazilian medical schools. It offers insights into the current landscape of sleep medicine education in Brazil and lays groundwork for future efforts to integrate these essential subjects into medical school curricula.

Chinese formula Guben-Jiannao Ye alleviates the dysfunction of circadian and sleep rhythms in APP/PS1 mice implicated in activation of the PI3K/AKT/mTOR signaling pathway

ETHNOPHARMACOLOGICAL RELEVANCE

The Chinese formula Guben-Jiannao Ye (GBJNY) formula has a long history of usage in traditional Chinese medicine (TCM) for the treatment of learning and memory disorders as well as senile insomnia. This formulation is derived from Sun Simiao's five tonic pills. Furthermore, modern pharmacological investigations have revealed its ability to improve cognitive impairment and ameliorate sleep-wake circadian rhythm disorders. However, the precise mechanism underlying its efficacy remains elusive.

AIM OF THE STUDY

The current research explored the modulatory effects and possible mechanisms of GBJNY in circadian rhythm sleep-wake disorders and cognitive dysfunction in Alzheimer's disease using transcriptome sequencing and experimental validation.

MATERIALS AND METHODS

The LC-MS/MS tandem technology was utilized to qualitatively discern the active components present in GBJNY. The APP/PS1 mice received continuous treatment with GBJNY or Melatonin for 3 months. The learning and memory abilities of mice were assessed utilizing the Morris water maze (MWM) test, while sleep changes were studied utilizing the electroencephalogram (EEG) and electromyogram (EMG). Concurrently, mice's hippocampus clock gene rhythmicity was investigated. Subsequently, we employed HE staining, Golgi staining, and immunofluorescence to observe GBJNY's impact on synaptic damage and neuronal loss. We performed high-throughput sequencing to analyze the mRNA expression profiles of mice, aiming to identify differentially expressed genes (DEGs). Subsequently, we conducted GO and KEGG enrichment analyses to explore associated signaling pathways. Furthermore, we evaluated the expression levels of proteins involved in the PI3K/AKT/mTOR pathway and Aβ deposition in the hippocampus of mice. Through this comprehensive approach, we sought to elucidate and validate the potential mechanisms of action of GBJNY in APP/PS1 mice.

RESULTS

Results showed 216 DEGs. Following this, we conducted GO enrichment and KEGG pathway analyses to delve deeper into the distinctions and fundamental functions of the mRNA target genes. The enrichment analysis underscored the prominence of the PI3K/Akt/mTOR signaling pathway as the most pivotal among them. Through in vivo experiments, it was further demonstrated that the administration of GBJNY enhanced memory and learning capacities in APP/PS1 mice. Additionally, GBJNY treatment resulted in alterations in the sleep-wake circadian rhythm, characterized by reduced wakefulness and an increase in non-rapid eye movement (NREM) sleep. Moreover, alterations in the peak expression of Per1, Per2, Clock, Cry1, Cry2, and Bmal1 mRNA were noted in the hippocampus of treated mice. Particularly noteworthy were the observed reductions in amyloid-beta (Aβ) deposition within the hippocampus, improvements in neuronal synaptic integrity, and upregulation of mTOR, Akt, and PI3K protein expression in the hippocampal region. These findings underscore the critical involvement of the PI3K/Akt/mTOR signaling pathway in mitigating disturbances in sleep-wake circadian rhythms.

CONCLUSIONS

GBJNY enhanced the cognitive performance of APP/PS1 mice and altered clock gene expression patterns, alleviating sleep-wake circadian rhythm disruptions. The fundamental mechanism appears to be linked to the PI3K/Akt/mTOR pathway regulation, offering a foundation for potential clinical applications.

Alterations in Circadian Rhythms, Sleep, and Physical Activity in COVID-19: Mechanisms, Interventions, and Lessons for the Future

Although the world is acquitting from the throes of COVID-19 and returning to the regularity of life, its effects on physical and mental health are prominently evident in the post-pandemic era. The pandemic subjected us to inadequate sleep and physical activities, stress, irregular eating patterns, and work hours beyond the regular rest-activity cycle. Thus, perturbing the synchrony of the regular circadian clock functions led to chronic psychiatric and neurological disorders and poor immunological response in several COVID-19 survivors. Understanding the links between the host immune system and viral replication machinery from a clock-infection biology perspective promises novel avenues of intervention. Behavioral improvements in our daily lifestyle can reduce the severity and expedite the convalescent stage of COVID-19 by maintaining consistent eating, sleep, and physical activity schedules. Including dietary supplements and nutraceuticals with prophylactic value aids in combating COVID-19, as their deficiency can lead to a higher risk of infection, vulnerability, and severity of COVID-19. Thus, besides developing therapeutic measures, perpetual healthy practices could also contribute to combating the upcoming pandemics. This review highlights the impact of the COVID-19 pandemic on biological rhythms, sleep-wake cycles, physical activities, and eating patterns and how those disruptions possibly contribute to the response, severity, and outcome of SARS-CoV-2 infection.

Effects of sex, mating status, and genetic background on circadian behavior in Drosophila

Circadian rhythms play a crucial role in regulating behavior, physiology, and health. Sexual dimorphism, a widespread phenomenon across species, influences circadian behaviors. Additionally, post-mating physiological changes in females are known to modulate various behaviors, yet their effects on circadian rhythms remain underexplored. Here, using Drosophila melanogaster, a powerful model for studying circadian mechanisms, we systematically assessed the impact of sex and mating status on circadian behavior. We measured circadian period length and rhythm strength in virgin and mated males and females, including females mated to males lacking Sex Peptide (SP), a key mediator of post-mating changes. Across four wild-type and control strains, we found that males consistently exhibited shorter circadian periods than females, regardless of mating status, suggesting that circadian period length is a robust sexually dimorphic trait. In contrast, rhythm strength was influenced by the interaction between sex and mating status, with female mating generally reducing rhythm strength in the presence of SP signaling. Notably, genetic background significantly modulated these effects on rhythm strength. Our findings demonstrate that while circadian period length is a stable sex-specific trait, rhythm strength is shaped by a complex interplay between sex, mating status, and genetic background. This study advances our understanding of how sex and mating influence circadian rhythms in Drosophila and provides a foundation for future research into sexually dimorphic mechanisms underlying human diseases associated with circadian disruptions.

Association between Accelerometer-Measured Irregular Sleep Duration and Longitudinal Changes in Body Mass Index in Older Adults

Irregular sleep duration may disrupt circadian rhythms and contribute to metabolic, behavioral, and mood changes, potentially increasing the risk for obesity. However, quantitative data on the relationship between sleep duration irregularity and weight change are lacking. In this prospective study, we analyzed data from 10,572 participants (mean age: 63 years) in the UK Biobank who wore accelerometers for a week between 2013-2015 and had two body mass index (BMI; kg/m2) measurements on average 2.5 years apart. Irregular sleep duration was assessed by the within-person standard deviation (SD) of 7-night accelerometer-measured sleep duration. Participants with sleep duration SD >60 minutes versus ≤30 minutes had 0.24 kg/m2 (95% CI: 0.08, 0.40) higher BMI change (kg/m2), standardized to three-year intervals, and 80% (95% CI: 1.28, 2.52) higher risk for incident obesity, after adjusting for sociodemographic factors, shift work, and baseline BMI or follow-up period (p-trend<0.02 for both). These associations remained consistent after adjusting for lifestyle, comorbidities, and other sleep factors, including sleep duration. Age, sex, baseline BMI, and genetic predisposition to higher BMI (measured with a polygenic risk score) did not appear to modify the association. Since irregular sleep duration is common, trials of interventions targeting sleep irregularity might lead to new public health strategies that tackle obesity.

Validation of intrinsic capacity and healthy sleep pattern in middle-aged and older adults: a longitudinal Chinese study assessing healthy ageing

OBJECTIVES

Intrinsic capacity (IC), a multidimensional construct encompassing mental and physical capacities, has been established in the aging framework by the World Health Organization. However, the detailed relationship between IC and Chinese sleep patterns (nighttime sleep and post-lunch naps) remains inadequately elucidated.

METHODS

Participants in this study were individuals aged ≥45 years residing in China, included in the China Health and Retirement Longitudinal Study (CHARLS). We analyzed 4 years of CHARLS data from the first wave (May 2011-March 2012) to the second wave (July 2015-January 2016). Data from these waves were utilized for longitudinal analysis. Self-reported data included nighttime sleep and nap duration, along with other baseline characteristics. The IC evaluation involved physical examinations and blood tests. Initially, linear regression was used to assess the relationship between total sleep duration, nighttime sleep duration, nap duration, and IC change between the two waves that were determined by marginal effects (ME) and their corresponding 95% confidence intervals (CIs). Regression splines were employed to explore potential nonlinear associations. Subgroup and sensitivity analyses were conducted to investigate the heterogeneity of IC change under specific conditions and the robustness of our results. Mediation analysis was performed to identify potential factors mediating the relationship between sleep patterns and IC change.

RESULTS

Both excessive (>10 h) (total, ME: -1.12; 95% CI: -1.61, -0.64; nighttime, ME: -1.44; 95% CI: -2.29, -0.59) and insufficient (<6 h) sleep duration (total, ME: -0.43; 95% CI: -0.68, -0.18; nighttime, ME: -0.50; 95% CI: -0.73, -0.27) negatively impacted IC change. Moderate naps (≤60 min) mitigated the decline in IC change (ME: 0.28; 95% CI: 0.07, 0.49). IC values decreased at the slowest rate when nap time constituted one-seventh of total sleep time. The onset of dyslipidemia partially mediated the association between naps (≤60 min) and IC change (P =  0.02).

CONCLUSIONS

These findings suggest that maintaining a healthy sleep pattern of 6-8 h of nighttime or total sleep, along with a post-lunch nap of ≤60 min, helps preserve optimal IC or delay its decline. This is particularly beneficial for cognitive, psychological, and locomotion performance among middle-aged and older adults.

Sleep and diurnal alternative polyadenylation sites associated with human APA-linked brain disorders

Disruption of sleep and circadian rhythms are a comorbid feature of many pathologies, and can negatively influence many health conditions, including neurodegenerative disease, metabolic illness, cancer, and various neurological disorders. Genetic association studies linking sleep and circadian disturbances with disease susceptibility have mainly focused on changes in gene expression due to mutations, such as single-nucleotide polymorphisms. The interaction between sleep and/or circadian rhythms with the use of Alternative Polyadenylation (APA) has been largely undescribed, particularly in the context of other disorders. APA generates transcript isoforms by utilizing various polyadenylation sites (PASs) from the same gene affecting its mRNA translation, stability, localization, and subsequent function. Here we identified unique APAs expressed in rat brain over time-of-day, immediately following sleep deprivation, and the subsequent recovery period. From these data, we performed a secondary analysis of these sleep- or time-of-day associated PASs with recently described APA-linked human brain disorder susceptibility genes.

Cross-species evidence for a developmental origin of adult hypersomnia with loss of synaptic adhesion molecules beat-Ia/CADM2

Idiopathic hypersomnia (IH) is a poorly-understood sleep disorder characterized by excessive daytime sleepiness despite normal nighttime sleep. Combining human genomics with behavioral and mechanistic studies in fish and flies, we uncover a role for beat-Ia/CADM2 , synaptic adhesion molecules of the immunoglobulin superfamily, in excessive sleepiness. Neuronal knockdown of Drosophila beat-Ia results in sleepy flies and loss of the vertebrate ortholog of beat-Ia , CADM2 , results in sleepy fish. We delineate a developmental function for beat-Ia in synaptic elaboration of neuropeptide F (NPF) neurites projecting to the suboesophageal zone (SEZ) of the fly brain. Brain connectome and experimental evidence demonstrate these NPF outputs synapse onto a subpopulation of SEZ GABAergic neurons to stabilize arousal. NPF is the Drosophila homolog of vertebrate neuropeptide Y (NPY), and an NPY receptor agonist restores sleep to normal levels in zebrafish lacking CADM2 . These findings point towards NPY modulation as a treatment target for human hypersomnia.

Cardiovascular health and cancer mortality: evidence from US NHANES and UK Biobank cohort studies

BACKGROUND

The American Heart Association recently introduced a novel cardiovascular health (CVH) metric, Life's Essential 8 (LE8), for health promotion. However, the relationship between LE8 and cancer mortality risk remains uncertain.

METHODS

We investigated 17,076 participants from US National Health and Nutrition Examination Survey (US NHANES) and 272,727 participants from UK Biobank, all free of cancer at baseline. The CVH score, based on LE8 metrics, incorporates four health behaviors (diet, physical activity, smoking, and sleep) and four health factors (body mass index, lipid, blood glucose, and blood pressure). Self-reported questionnaires assessed health behaviors. Primary outcomes were mortality rates for total cancer and its subtypes. The association between CVH score (continuous and categorical variable) and outcomes was examined using Cox model with adjustments. Cancer subtypes-related polygenic risk score (PRS) was constructed to evaluate its interactions with CVH on cancer death risk.

RESULTS

Over 141,526 person-years in US NHANES, 424 cancer-related deaths occurred, and in UK Biobank, 8,872 cancer deaths were documented during 3,690,893 person-years. High CVH was associated with reduced overall cancer mortality compared to low CVH (HR 0.58, 95% CI 0.37-0.91 in US NHANES; 0.51, 0.46-0.57 in UK Biobank). Each one-standard deviation increase in CVH score was linked to a 19% decrease in cancer mortality (HR: 0.81; 95% CI: 0.73-0.91) in US NHANES and a 19% decrease (HR: 0.81; 95% CI: 0.79-0.83) in UK Biobank. Adhering to ideal CVH was linearly associated with decreased risks of death from lung, bladder, liver, kidney, esophageal, breast, colorectal, pancreatic, and gastric cancers in UK Biobank. Furthermore, integrating genetic data revealed individuals with low PRS and high CVH exhibited the lowest mortality from eight cancers (HRs ranged from 0.36 to 0.57) compared to those with high PRS and low CVH. No significant modification of the association between CVH and mortality risk for eight cancers by genetic predisposition was observed. Subgroup analyses showed a more pronounced protective association for overall cancer mortality among younger participants and those with lower socio-economic status.

CONCLUSIONS

Maintaining optimal CVH is associated with a substantial reduction in the risk of overall cancer mortality. Adherence to ideal CVH correlates linearly with decreased mortality risk across multiple cancer subtypes. Individuals with both ideal CVH and high genetic predisposition demonstrated significant health benefits. These findings support adopting ideal CVH as an intervention strategy to mitigate cancer mortality risk and promote healthy aging.

Acetate enables metabolic fitness and cognitive performance during sleep disruption

Sleep is essential for overall health, and its disruption is linked to increased risks of metabolic, cognitive, and cardiovascular dysfunctions; however, the molecular mechanisms remain poorly understood. This study investigated how sleep disturbances contribute to metabolic imbalance and cognition impairment using a chronic sleep fragmentation (SF) mouse model. SF mice exhibited impaired cognition, glucose metabolism, and insulin sensitivity compared with controls. We identified increased acetate levels in hypothalamic astrocytes as a defensive response in SF mice. Through acetate infusion or astrocyte-specific Acss1 deletion to elevate acetate levels, we observed mitigated metabolic and cognitive impairments in SF mice. Mechanistically, acetate binds and activates pyruvate carboxylase, thereby restoring glycolysis and the tricarboxylic acid cycle. Among individuals most commonly affected by SF, patients with obstructive sleep apnea exhibited elevated acetate levels when coupled with type 2 diabetes. Our study uncovers the protective effect of acetate against sleep-induced metabolic and cognitive impairments.

An artificial intelligence powered study of enlarged facial pore prevalence on one million Chinese from different age groups and its correlation with environmental factors

BACKGROUND

Enlarged pores are amidst one of the top cosmetic concerns, especially among Chinese. Many small-group studies have been conducted in understanding their prevalence and beauty relevance. Nonetheless, population-level investigations are still lacking because of gaps in data collection and processing of large-scale studies. Owing to the recent technological advancement enabled by artificial intelligence, databases on the scale of millions can be processed and analyzed readily.

MATERIALS AND METHODS

Powered by big data capabilities, revealed a number of novel trends on pore conditions among over-a-million Chinese participants recruited via the "You Look Great Today" mobile application. A scoring model was constructed, which demonstrated high consistency with conventional grading method from dermatologists. Environmental data (weather, air pollution, light at night satellite) were applied to correlate with pore severity.

RESULTS

Intraclass correlations between the two scoring systems were strong, with coefficients ranging from 0.79 to 0.92 for different facial areas. Statistical differences in pore severity among all four facial areas (cheek, forehead, nose, and overall) were observed, with the cheek exhibiting the most severe pore condition. Interestingly, Chinese men suffer from more severe pore condition than females. Multiple environmental factors exhibited strong correlations with cheek pore severity and were statistically fitted into linear regressions. Specifically, incremental risk with Each Low Temperature, Low Humidity, And High Solar Exposure correlate to worse cheek pore conditions. Although the Pearson correlation was low between cheek pore severity and light at night, comparison between representative cities demonstrated that in geologically similar cities, higher light at night corresponds to more severe cheek pore conditions.

CONCLUSION

Our study is showcasing a robust and reliable AI model in facial pore evaluation. More importantly, insights uncovered using this facile approach also bear significant cosmetic ramifications in treatment of pore enlargement.

Sleep and diurnal alternative polyadenylation sites associated with human APA-linked brain disorders

Disruption of sleep and circadian rhythms are a comorbid feature of many pathologies, and can negatively influence many health conditions, including neurodegenerative disease, metabolic illness, cancer, and various neurological disorders. Genetic association studies linking sleep and circadian disturbances with disease susceptibility have mainly focused on changes in gene expression due to mutations, such as single-nucleotide polymorphisms. The interaction between sleep and/or circadian rhythms with the use of Alternative Polyadenylation (APA) has been largely undescribed, particularly in the context of other disorders. APA is a process that generates various transcript isoforms of the same gene affecting its mRNA translation, stability, localization, and subsequent function. Here we identified unique APAs expressed in rat brain over time-of-day, immediately following sleep deprivation, and the subsequent recovery period. From these data, we performed a secondary analysis of these sleep- or time-of-day associated PASs with recently described APA-linked human brain disorder susceptibility genes.

The Genetics of Human Sleep and Sleep Disorders

Healthy sleep is vital for humans to achieve optimal health and longevity. Poor sleep and sleep disorders are strongly associated with increased morbidity and mortality. However, the importance of good sleep continues to be underrecognized. Mechanisms regulating sleep and its functions in humans remain mostly unclear even after decades of dedicated research. Advancements in gene sequencing techniques and computational methodologies have paved the way for various genetic analysis approaches, which have provided some insights into human sleep genetics. This review summarizes our current knowledge of the genetic basis underlying human sleep traits and sleep disorders. We also highlight the use of animal models to validate genetic findings from human sleep studies and discuss potential molecular mechanisms and signaling pathways involved in the regulation of human sleep.

Circadian rhythm disruption and endocrine-related tumors

This review delved into the intricate relationship between circadian clocks and physiological processes, emphasizing their critical role in maintaining homeostasis. Orchestrated by interlocked clock genes, the circadian timekeeping system regulates fundamental processes like the sleep-wake cycle, energy metabolism, immune function, and cell proliferation. The central oscillator in the hypothalamic suprachiasmatic nucleus synchronizes with light-dark cycles, while peripheral tissue clocks are influenced by cues such as feeding times. Circadian disruption, linked to modern lifestyle factors like night shift work, correlates with adverse health outcomes, including metabolic syndrome, cardiovascular diseases, infections, and cancer. We explored the molecular mechanisms of circadian clock genes and their impact on metabolic disorders and cancer pathogenesis. Specific associations between circadian disruption and endocrine tumors, spanning breast, ovarian, testicular, prostate, thyroid, pituitary, and adrenal gland cancers, are highlighted. Shift work is associated with increased breast cancer risk, with PER genes influencing tumor progression and drug resistance. CLOCK gene expression correlates with cisplatin resistance in ovarian cancer, while factors like aging and intermittent fasting affect prostate cancer. Our review underscored the intricate interplay between circadian rhythms and cancer, involving the regulation of the cell cycle, DNA repair, metabolism, immune function, and the tumor microenvironment. We advocated for integrating biological timing into clinical considerations for personalized healthcare, proposing that understanding these connections could lead to novel therapeutic approaches. Evidence supports circadian rhythm-focused therapies, particularly chronotherapy, for treating endocrine tumors. Our review called for further research to uncover detailed connections between circadian clocks and cancer, providing essential insights for targeted treatments. We emphasized the importance of public health interventions to mitigate lifestyle-related circadian disruptions and underscored the critical role of circadian rhythms in disease mechanisms and therapeutic interventions.

[Effects of Extreme Environments on Human Sleep]

Recently, with the rapid growth of the global population and the exhaustion of resources, exploration activities in extreme environments such as the polar regions, the outer space, the deep sea, the deep underground and highlands are becoming increasingly more frequent. This in-depth exploration of the external environment and the consequent dramatic changes in lifestyles impact on sleep, a basic life activity of humans, in ways that cannot be overlooked. the basic life activity of human beings. Sleep, a basic life activity and the result of the evolution of organisms to adapt to their environment, is closely associated with sleep homeostasis and endogenous rhythms. However, external environmental changes and lifestyle shifts in extreme environments have had a significant impact on the patterns and the quality of sleep in humans. Furthermore, this impact can lead to many physiological and psychological problems, posing a great threat to human health. In this review, we delved into the specific effects of different extreme natural environments and enclosed environments on sleep, elaborating on how these environments alter the patterns and the quality of sleep in humans. In addition, we summarized the changes in human sleep under extreme environments to help gain a better understanding of the mechanisms by which these specific environments impact human sleep. It is expected that this review will provide a solid theoretical foundation for optimizing long-term survival strategies in extreme environments and help humans adapt to and overcome the challenges posed by extreme environments more effectively.

Maternal high fat diet induces circadian clock-independent endocrine alterations impacting the metabolism of the offspring

Maternal obesity has long-term effects on offspring metabolic health. Among the potential mechanisms, prior research has indicated potential disruptions in circadian rhythms and gut microbiota in the offspring. To challenge this hypothesis, we implemented a maternal high fat diet regimen before and during pregnancy, followed by a standard diet after birth. Our findings confirm that maternal obesity impacts offspring birth weight and glucose and lipid metabolisms. However, we found minimal impact on circadian rhythms and microbiota that are predominantly driven by the feeding/fasting cycle. Notably, maternal obesity altered rhythmic liver gene expression, affecting mitochondrial function and inflammatory response without disrupting the hepatic circadian clock. These changes could be explained by a masculinization of liver gene expression similar to the changes observed in polycystic ovarian syndrome. Intriguingly, such alterations seem to provide the first-generation offspring with a degree of protection against obesity when exposed to a high fat diet.

Postoperative Delirium and the Older Adult: Untangling the Confusion

Postoperative delirium is one of the most prevalent postoperative complications, affecting mostly older adults. Its incidence is expected to rise because of surgical advances, shifting demographics, and increased life expectancy. Although an acute alteration in brain function, postoperative delirium is associated with adverse outcomes, including progressive cognitive decline and dementia, that place significant burdens on patients' lives and healthcare systems. This has prompted efforts to understand the mechanisms of postoperative delirium to provide effective prevention and treatment. There are multiple mechanisms involved in the etiology of postoperative delirium that share similarities with the physiological changes associated with the aging brain. In addition, older patients often have multiple comorbidities including increased cognitive impairment that is also implicated in the genesis of delirium. These tangled connections pinpointed a shift toward creation of a holistic model of the pathophysiology of postoperative delirium. Scientific advancements integrating clinical risk factors, possible postoperative delirium biomarkers, genetic features, digital platforms, and other biotechnical and information technological innovations, will become available in the near future. Advances in artificial intelligence, for example, will aggregate cognitive testing platforms with patient-specific postoperative delirium risk stratification studies, panels of serum and cerebrospinal fluid molecules, electroencephalogram signatures, and gut microbiome features, along with the integration of novel polygenetic variants of sleep and cognition. These advances will allow for the enrollment of high-risk patients into prevention programs and help uncover new pharmacologic targets.

Sleep and Oxidative Stress: Current Perspectives on the Role of NRF2

Sleep is a fundamental conserved physiological state across evolution, suggesting vital biological functions that are yet to be fully clarified. However, our understanding of the neural and molecular basis of sleep regulation has increased rapidly in recent years. Among various processes implicated in controlling sleep homeostasis, a bidirectional relationship between sleep and oxidative stress has recently emerged. One proposed function of sleep may be the mitigation of oxidative stress in both brain and peripheral tissues, contributing to the clearance of reactive species that accumulate during wakefulness. Conversely, reactive species, such as reactive oxygen species (ROS) and reactive nitrogen species (RNS), at physiological levels, may act as signaling agents to regulate redox-sensitive transcriptional factors, enzymes, and other effectors involved in the regulation of sleep. As a primary sensor of intracellular oxidation, the transcription factor NRF2 is emerging as an indispensable component to maintain cellular redox homeostasis during sleep. Indeed, a number of studies have revealed an association between NRF2 dysfunction and the most common sleep conditions, including sleep loss, obstructive sleep apnea, and circadian sleep disturbances. This review examines the evidence of the intricate link between oxidative stress and NRF2 function in the context of sleep, and highlights the potential of NRF2 modulators to alleviate sleep disturbances.

Evo-devo applied to sleep research: an approach whose time has come

Sleep occurs in all animals but its amount, form, and timing vary considerably between species and between individuals. Currently, little is known about the basis for these differences, in part, because we lack a complete understanding of the brain circuitry controlling sleep-wake states and markers for the cell types which can identify similar circuits across phylogeny. Here, I explain the utility of an "Evo-devo" approach for comparative studies of sleep regulation and function as well as for sleep medicine. This approach focuses on the regulation of evolutionary ancient transcription factors which act as master controllers of cell-type specification. Studying these developmental transcription factor cascades can identify novel cell clusters which control sleep and wakefulness, reveal the mechanisms which control differences in sleep timing, amount, and expression, and identify the timepoint in evolution when different sleep-wake control neurons appeared. Spatial transcriptomic studies, which identify cell clusters based on transcription factor expression, will greatly aid this approach. Conserved developmental pathways regulate sleep in mice, Drosophila, and C. elegans. Members of the LIM Homeobox (Lhx) gene family control the specification of sleep and circadian neurons in the forebrain and hypothalamus. Increased Lhx9 activity may account for increased orexin/hypocretin neurons and reduced sleep in Mexican cavefish. Other transcription factor families specify sleep-wake circuits in the brainstem, hypothalamus, and basal forebrain. The expression of transcription factors allows the generation of specific cell types for transplantation approaches. Furthermore, mutations in developmental transcription factors are linked to variation in sleep duration in humans, risk for restless legs syndrome, and sleep-disordered breathing. This paper is part of the "Genetic and other molecular underpinnings of sleep, sleep disorders, and circadian rhythms including translational approaches" collection.

Revolutionizing Sleep Health: The Emergence and Impact of Personalized Sleep Medicine

Personalized sleep medicine represents a transformative shift in healthcare, emphasizing individualized approaches to optimizing sleep health, considering the bidirectional relationship between sleep and health. This field moves beyond conventional methods, tailoring care to the unique physiological and psychological needs of individuals to improve sleep quality and manage disorders. Key to this approach is the consideration of diverse factors like genetic predispositions, lifestyle habits, environmental factors, and underlying health conditions. This enables more accurate diagnoses, targeted treatments, and proactive management. Technological advancements play a pivotal role in this field: wearable devices, mobile health applications, and advanced diagnostic tools collect detailed sleep data for continuous monitoring and analysis. The integration of machine learning and artificial intelligence enhances data interpretation, offering personalized treatment plans based on individual sleep profiles. Moreover, research on circadian rhythms and sleep physiology is advancing our understanding of sleep's impact on overall health. The next generation of wearable technology will integrate more seamlessly with IoT and smart home systems, facilitating holistic sleep environment management. Telemedicine and virtual healthcare platforms will increase accessibility to specialized care, especially in remote areas. Advancements will also focus on integrating various data sources for comprehensive assessments and treatments. Genomic and molecular research could lead to breakthroughs in understanding individual sleep disorders, informing highly personalized treatment plans. Sophisticated methods for sleep stage estimation, including machine learning techniques, are improving diagnostic precision. Computational models, particularly for conditions like obstructive sleep apnea, are enabling patient-specific treatment strategies. The future of personalized sleep medicine will likely involve cross-disciplinary collaborations, integrating cognitive behavioral therapy and mental health interventions. Public awareness and education about personalized sleep approaches, alongside updated regulatory frameworks for data security and privacy, are essential. Longitudinal studies will provide insights into evolving sleep patterns, further refining treatment approaches. In conclusion, personalized sleep medicine is revolutionizing sleep disorder treatment, leveraging individual characteristics and advanced technologies for improved diagnosis, treatment, and management. This shift towards individualized care marks a significant advancement in healthcare, enhancing life quality for those with sleep disorders.