Exosomes and metabolic functionin mice exposed to alternating dark-light cycles mimicking night shift work schedules

Sleep is an important modulator of metabolic function. Disruptions of sleep in circadian rhythm are common in modern societies and are associated with increased risk of developing cardiometabolic disorders. Exosomes are ubiquitous extracellular vesicles that may play a mechanistic role in metabolic derangements. We hypothesized that alternating dark-light cycles mimicking shift work in mice would alter fecal microbiota and colonic epithelium permeability and alter plasma exosome cargo and metabolic function. C57BL/6 mice were randomly assigned to (i) control day light (CL), or (ii) inverted dark-light every 2 weeks for 8 weeks (IN). Body weight, fat mass and HOMA-IR were measured, along with Tregs, metabolic, and resident macrophages in visceral white adipose tissue (vWAT). Fecal water samples were incubated with confluent colonic epithelium cell cultures in electric cell-substrate impedance sensing (ECIS) arrays, and plasma exosomes were added to differentiated adipocytes and insulin-induced pAKT/AKT expression changes were assessed by western blots. Mice exposed to IN showed elevated HOMA-IR, and their fecal samples showed altered microbiota which promote increased permeability of the colonic epithelial cell barrier. Plasma exosomes decreased pAKT/AKT responses to exogenous insulin compared to CL, and altered expression of circadian clock genes. Inflammatory macrophages (Ly-6chigh) were increased in IN-exposed vWAT, while Tregs were decreased. Thus, gut microbiota and the cargo of plasma exosomes are altered by periodic shifts in environmental lighting, and effectively alter metabolic function, possibly via induction of systemic inflammation and altered clock expression in target tissues. Further exploration of exosomal miRNA signatures in shift workers and their putative metabolic organ cell targets appears warranted

Aorta macrophage inflammatory and epigenetic changes in a murine model of obstructive sleep apnea: Potential role of CD36

Obstructive sleep apnea (OSA) affects 8-10% of the population, is characterized by chronic intermittent hypoxia (CIH), and causally associates with cardiovascular morbidities. In CIH-exposed mice, closely mimicking the chronicity of human OSA, increased accumulation and proliferation of pro-inflammatory metabolic M1-like macrophages highly expressing CD36, emerged in aorta. Transcriptomic and MeDIP-seq approaches identified activation of pro-atherogenic pathways involving a complex interplay of histone modifications in functionally-relevant biological pathways, such as inflammation and oxidative stress in aorta macrophages. Discontinuation of CIH did not elicit significant improvements in aorta wall macrophage phenotype. However, CIH-induced aorta changes were absent in CD36 knockout mice, Our results provide mechanistic insights showing that CIH exposures during sleep in absence of concurrent pro-atherogenic settings (i.e., genetic propensity or dietary manipulation) lead to the recruitment of CD36(+)high macrophages to the aortic wall and trigger atherogenesis. Furthermore, long-term CIH-induced changes may not be reversible with usual OSA treatment

Chronic sleep disruption alters gut microbiota, induces systemic and adipose tissue inflammation and insulin resistance in mice.

Chronic sleep fragmentation (SF) commonly occurs in human populations, and although it does not involve circadian shifts or sleep deprivation, it markedly alters feeding behaviors ultimately promoting obesity and insulin resistance. These symptoms are known to be related to the host gut microbiota. Mice were exposed to SF for 4 weeks and then allowed to recover for 2 weeks. Taxonomic profiles of fecal microbiota were obtained prospectively, and conventionalization experiments were performed in germ-free mice. Adipose tissue insulin sensitivity and inflammation, as well as circulating measures of inflammation, were assayed. Effect of fecal water on colonic epithelial permeability was also examined. Chronic SF-induced increased food intake and reversible gut microbiota changes characterized by the preferential growth of highly fermentative members of Lachnospiraceae and Ruminococcaceae and a decrease of Lactobacillaceae families. These lead to systemic and visceral white adipose tissue inflammation in addition to altered insulin sensitivity in mice, most likely via enhanced colonic epithelium barrier disruption. Conventionalization of germ-free mice with SF-derived microbiota confirmed these findings. Thus, SF-induced metabolic alterations may be mediated, in part, by concurrent changes in gut microbiota, thereby opening the way for gut microbiome-targeted therapeutics aimed at reducing the major end-organ morbidities of chronic SF

Circulating exosomes potentiate tumor malignant properties in a mouse model of chronic sleep fragmentation

Background: Chronic sleep fragmentation (SF) increases cancer aggressiveness in mice. Exosomes exhibit pleiotropic biological functions, including immune regulatory functions, antigen presentation, intracellular communication and inter-cellular transfer of RNA and proteins. We hypothesized that SF-induced alterations in biosynthesis and cargo of plasma exosomes may affect tumor cell properties. Results: SF-derived exosomes increased tumor cell proliferation (~13%), migration (~2.3-fold) and extravasation (~10%) when compared to exosomes from SC-exposed mice. Similarly, Pre exosomes from OSA patients significantly enhanced proliferation and migration of human adenocarcinoma cells compared to Post. SF-exosomal cargo revealed 3 discrete differentially expressed miRNAs, and exploration of potential mRNA targets in TC1 tumor cells uncovered 132 differentially expressed genes that encode for multiple cancer-related pathways. Methods: Plasma-derived exosomes from C57/B6 mice exposed to 6 wks of SF or sleep control (SC), and from adult human patients with obstructive sleep apnea (OSA) before (Pre) and after adherent treatment for 6 wks (Post) were co-cultured with mouse lung TC1 or human adenocarcinoma tumor cell lines, respectively. Proliferation, migration, invasion, endothelial barrier integrity and extravasation assays of tumor cells were performed. Plasma mouse exosomal miRNAs were profiled with arrays, and transcriptomic assessments of TC1 cells exposed to SF or SC exosomes were conducted to identify gene targets. Conclusions: Chronic SF induces alterations in exosomal miRNA cargo that alter the biological properties of TC1 lung tumor cells to enhance their proliferative, migratory and extravasation properties, and similar findings occur in OSA patients, in whom SF is a constitutive component of their sleep disorder. Thus, exosomes could participate, at least in part, in the adverse cancer outcomes observed in OSA

Inflammatory Markers and Obstructive Sleep Apnea in Obese Children: The NANOS Study

Introduction: Obesity and obstructive sleep apnea syndrome (OSA) are common coexisting conditions associated with a chronic low-grade inflammatory state underlying some of the cognitive, metabolic, and cardiovascular morbidities. Aim: To examine the levels of inflammatory markers in obese community-dwelling children with OSA, as compared to no-OSA, and their association with clinical and polysomnographic (PSG) variables. Methods. In this cross-sectional, prospective multicenter study, healthy obese Spanish children (ages 4-15 years) were randomly selected and underwent nocturnal PSG followed by a morning fasting blood draw. Plasma samples were assayed for multiple inflammatory markers. Results: 204 children were enrolled in the study; 75 had OSA, defined by an obstructive respiratory disturbance index (RDI) of 3 events/hour total sleep time (TST). BMI, gender, and age were similar in OSA and no-OSA children. Monocyte chemoattractant protein-1 (MCP-1) and plasminogen activator inhibitor-1 (PAI-1) levels were significantly higher in OSA children, with interleukin-6 concentrations being higher in moderate-severe OSA (i.e., AHI > 5/hrTST; P < 0.01), while MCP-1 levels were associated with more prolonged nocturnal hypercapnia (P < 0.001). Conclusion: IL-6, MCP-1, and PAI-1 are altered in the context of OSA among community-based obese children further reinforcing the proinflammatory effects of sleep disorders such as OSA. This trial is registered with ClinicalTrials.gov NCT01322763

Heterogeneity of Melanoma Cell Responses to Sleep Apnea-Derived Plasma Exosomes and to Intermittent Hypoxia

Obstructive sleep apnea (OSA) is associated with increased cutaneous melanoma incidence and adverse outcomes. Exosomes are secreted by most cells, and play a role in OSA-associated tumor progression and metastasis. We aimed to study the effects of plasma exosomes from OSA patients before and after adherent treatment with continuous positive airway pressure (CPAP) on melanoma cells lines, and also to identify exosomal miRNAs from melanoma cells exposed to intermittent hypoxia (IH) or normoxia. Plasma-derived exosomes were isolated from moderate-tosevere OSA patients before (V1) and after (V2) adherent CPAP treatment for one year. Exosomes were co-incubated with three3 different melanoma cell lines (CRL 1424; CRL 1619; CRL 1675) that are characterized by genotypes involving different mutations in BRAF, STK11, CDKN2A, and PTEN genes to assess the effect of exosomes on cell proliferation and migration, as well as on pAMK activity in the presence or absence of a chemical activator. Subsequently, CRL-1424 and CRL-1675 cells were exposed to intermittent hypoxia (IH) and normoxia, and exosomal miRNAs were identified followed by GO and KEG pathways and gene networks. The exosomes from these IH-exposed melanoma cells were also administered to THP1 macrophages to examine changes in M1 and M2 polarity markers. Plasma exosomes from V1 increased CRL-1424 melanoma cell proliferation and migration compared to V2, but not the other two cell lines. Exposure to CRL-1424 exosomes reduced pAMPK/tAMPK in V1 compared to V2, and treatment with AMPK activator reversed the effects. Unique exosomal miRNAs profiles were identified for CRL-1424 and CRL-1675 in IH compared to normoxia, with six miRNAs being regulated and several KEGG pathways were identified. Two M1 markers (CXCL10 and IL6) were significantly increased in monocytes when treated with exosomes from IH-exposed CRL-1424 and CRL-1625 cells. Our findings suggest that exosomes from untreated OSA patients increase CRL-1424 melanoma malignant properties, an effect that is not observed in two other melanoma cell lines. Exosomal cargo from CRL-1424 cells showed a unique miRNA signature compared to CRL-1675 cells after IH exposures, suggesting that melanoma cells are differentially susceptible to IH, even if they retain similar effects on immune cell polarity. It is postulated that mutations in STK-11 gene encoding for the serine/threonine kinase family that acts as a tumor suppressor may underlie susceptibility to IH-induced metabolic dysfunction, as illustrated by CRL1424 cells

Effects of the COVID‐19 lockdown on sleep duration in children and adolescents: A survey across different continents

Background A parent survey was conducted to assess the sleep habits of children residing in various countries before and during the SARS‐CoV‐2 pandemic. It was hypothesized that lockdown would be associated with increased sleep duration. Methods Outcomes were changes in bedtime, wake time, and sleep duration in the pandemic compared to before. Logistic regression was applied to evaluate the effects of age and covariates on outcomes. Results A total of 845 questionnaires completed from May 1 to June 10, 2020 were analyzed (45.8% female; age 3–17 years). During the pandemic, 23.1% of preschoolers, 46.2% of school‐age children, and 89.8% of adolescents were going to bed after 10 p.m. on weekdays compared to 7.1%, 9.4%, and 57.1% respectively before the pandemic, with these proportions being higher on weekends. Likewise, 42.5% of preschoolers, 61.3% of school‐age children, and 81.2% of adolescents were waking after 8 a.m. on weekdays (11.6%, 4.9%, and 10.3%, before) with these proportions being greater on weekends. Sleep duration did not change in 43% of participants on weekdays and in 46.2% on weekends. The 14–17 years group had fourfold increased odds for longer sleep duration on weekdays (p &lt; .01), and children aged 6–13 years had twofold increased odds for longer sleep duration on weekends relative to the 3–5 years age group (p = .01). Conclusions Although lockdown was associated with later bedtime and wake time, this shift did not alter sleep duration in more than 40% of children. Yet, compared to preschoolers, high school‐aged children were more likely to sleep more on weekdays and primary school children on weekends

Effects of the COVID‐19 lockdown on sleep duration in children and adolescents: A survey across different continents

Background A parent survey was conducted to assess the sleep habits of children residing in various countries before and during the SARS‐CoV‐2 pandemic. It was hypothesized that lockdown would be associated with increased sleep duration. Methods Outcomes were changes in bedtime, wake time, and sleep duration in the pandemic compared to before. Logistic regression was applied to evaluate the effects of age and covariates on outcomes. Results A total of 845 questionnaires completed from May 1 to June 10, 2020 were analyzed (45.8% female; age 3–17 years). During the pandemic, 23.1% of preschoolers, 46.2% of school‐age children, and 89.8% of adolescents were going to bed after 10 p.m. on weekdays compared to 7.1%, 9.4%, and 57.1% respectively before the pandemic, with these proportions being higher on weekends. Likewise, 42.5% of preschoolers, 61.3% of school‐age children, and 81.2% of adolescents were waking after 8 a.m. on weekdays (11.6%, 4.9%, and 10.3%, before) with these proportions being greater on weekends. Sleep duration did not change in 43% of participants on weekdays and in 46.2% on weekends. The 14–17 years group had fourfold increased odds for longer sleep duration on weekdays (p &lt; .01), and children aged 6–13 years had twofold increased odds for longer sleep duration on weekends relative to the 3–5 years age group (p = .01). Conclusions Although lockdown was associated with later bedtime and wake time, this shift did not alter sleep duration in more than 40% of children. Yet, compared to preschoolers, high school‐aged children were more likely to sleep more on weekdays and primary school children on weekends

Escalation of sleep disturbances amid the COVID-19 pandemic : a cross-sectional international study

© 2021 American Academy of Sleep MedicineStudy objectives: The stress imposed by the COVID-19 pandemic and ensuing social isolation could adversely affect sleep. As sleep problems may persist and hurt health, it is important to identify which populations have experienced changes in sleeping patterns during the pandemic and their extent. Methods: In Study 1, 3,062 responders from 49 countries accessed the survey website voluntarily between March 26 and April 26, 2020, and 2,562 (84%; age: 45.2 ± 14.5, 68% women) completed the study. In Study 2, 1,022 adult US responders were recruited for pay through Mechanical Turk, and 971 (95%; age 40.4 ± 13.6, 52% women) completed the study. The survey tool included demographics and items adapted from validated sleep questionnaires on sleep duration, quality and timing, and sleeping pills consumption. Results: In Study 1, 58% of the responders were unsatisfied with their sleep. Forty percent of the responders reported a decreased sleep quality vs before COVID-19 crisis. Self-reported sleeping pill consumption increased by 20% (P < .001). Multivariable analysis indicated that female sex, being in quarantine, and 31- to 45-years age group, reduced physical activity and adverse impact on livelihood were independently associated with more severe worsening of sleep quality during the pandemic. The majority of findings were reproduced in the independent cohort of Study 2. Conclusions: Changes imposed due to the pandemic have led to a surge in individuals reporting sleep problems across the globe. The findings raise the need to screen for worsening sleep patterns and use of sleeping aids, especially in more susceptible populations, namely, women and people with insecure livelihoods subjected to social isolation.info:eu-repo/semantics/publishedVersio