The effects of oral nicotine administration and abstinence on sleep in male C57BL/6J mice

Cerebrospinal Fluid Nitric Oxide Synthase is a Potential Mediator Between Cigarette Smoke Exposure and Sleep Disorders

Objective

Cigarette smoking and low peripheral nitric oxide synthase (NOS) levels are strongly associated with sleep disorders. However, whether cerebrospinal fluid (CSF) NOS relates to sleep disorders and whether CSF NOS mediates the relationship between cigarette smoking and sleep disorders is unclear.

Methods

We measured CSF levels of total NOS (tNOS) and its isoforms (inducible NOS [iNOS] and constitutive NOS [cNOS]) in 191 Chinese male subjects. We applied the Pittsburgh Sleep Quality Index (PSQI).

Results

The PSQI scores of active smokers were significantly higher than those of non-smokers, while CSF tNOS, iNOS, and cNOS were significantly lower (all p < 0.001). CSF tNOS, iNOS, and cNOS were negatively associated with PSQI scores in the general population (all p < 0.001). Mediation analysis suggested that CSF tNOS, iNOS, and cNOS mediate the relationship between smoking and PSQI scores, and the indirect effect accounted for 78.93%, 66.29%, and 81.65% of the total effect, respectively.

Conclusion

Cigarette smoking is associated with sleep disorders. Active smokers had significantly lower CSF levels of tNOS, iNOS, and cNOS. Furthermore, tNOS, iNOS, and cNOS mediate the relationship between cigarette smoking and sleep quality. This study provides insights into how cigarette smoke affects sleep disorders.

AKT2 modulates astrocytic nicotine responses in vivo

A better understanding of nicotine neurobiology is needed to reduce or prevent chronic addiction, ameliorate the detrimental effects of nicotine withdrawal, and increase successful cessation of use. Nicotine binds and activates two astrocyte-expressed nicotinic acetylcholine receptors (nAChRs), α4β2 and α7. We recently found that Protein kinase B-β (Pkb-β or Akt2) expression is restricted to astrocytes in mice and humans. To determine if AKT2 plays a role in astrocytic nicotinic responses, we generated astrocyte-specific Akt2 conditional knockout (cKO) and full Akt2 KO mice for in vivo and in vitro experiments. For in vivo studies, we examined mice exposed to chronic nicotine for two weeks in drinking water (200 μg/mL) and following acute nicotine challenge (0.09, 0.2 mg/kg) after 24 hrs. Our in vitro studies used cultured mouse astrocytes to measure nicotine-dependent astrocytic responses. We validated our approaches using lipopolysaccharide (LPS) exposure inducing astrogliosis. Sholl analysis was used to measure glial fibrillary acidic protein responses in astrocytes. Our data show that wild-type (WT) mice exhibit increased astrocyte morphological complexity during acute nicotine exposure, with decreasing complexity during chronic nicotine use, whereas Akt2 cKO mice showed increased astrocyte morphology complexity. In culture, we found that 100μM nicotine was sufficient for morphological changes and blocking α7 or α4β2 nAChRs prevented observed morphologic changes. Finally, we performed conditioned place preference (CPP) in Akt2 cKO mice and found that astrocytic AKT2 deficiency reduced nicotine preference compared to controls. These findings show the importance of nAChRs and Akt2 signaling in the astrocytic response to nicotine.

Melatonin alleviates depression-like behaviors and cognitive dysfunction in mice by regulating the circadian rhythm of AQP4 polarization

Depression is a common chronic psychiatric illness, which is resistant to medical treatments. While melatonin may alleviate certain depression symptoms, evidence for its efficacy against core symptoms is lacking. Here, we tested a mechanism whereby melatonin rescues the behavioral outcomes of the chronic unpredictable mild stress (CUMS) mouse model of depression. CUMS mice showed depressive behaviors to tail suspension, open field behavior, and sucrose preference test, and cognitive dysfunction in the Morris water maze. Impairments in these measures were relieved by melatonin treatment. Moreover, CUMS mice had impaired glymphatic function across the sleep-wake cycle due to the astrocytic loss and disturbance of circadian regulation of the polarized expression of aquaporin-4 (AQP4) water channels in perivascular astrocytes. EEG results in CUMS mice showed a reduced total sleep time and non-rapid eye movement (NREM) sleep, due to sleep fragmentation in the light phase. CUMS mice lost the normal rhythmic expressions of circadian proteins Per2, Cry2, Bmal1, Clock, and Per1. However, the melatonin treatment restored glymphatic system function and the polarization of AQP4, while improving sleep structure, and rectifying the abnormal expression of Per2, Bmal1, Clock, and Per1 in CUMS mice. Interestingly, Per2 expression correlated negatively with the polarization of AQP4. Further studies demonstrated that Per2 directed the location of AQP4 expression via interactions with the α-dystrobrevin (Dtna) subunit of AQP4 in primary cultured astrocytes. In conclusion, we report a new mechanism whereby melatonin improves depression outcomes by regulating the expression of the circadian protein Per2, maintaining the circadian rhythm of astrocytic AQP4 polarization, and restoring glymphatic function.

Factors associated with sleep quality in university students

To investigate factors associated with poor sleep quality. A cross-sectional study was conducted in 2019 with random sampling. Information on sleep was obtained using the Mini Sleep Questionnaire (MSQ). Independent variables included sociodemographic, behavioural, academic and psychological health characteristics. Adjusted analyzes were performed using Poisson regression. A total of 996 undergraduate students participated in the study. The poor sleep quality affected 23.1% of the sample (95%CI 20.5-25.9), ranging from 13.4% for those with little concern about violence in the neighbourhood to 36.5% for those with less social support. In the adjusted analysis, female sex [PR] 1.81; (95%CI 1.33-2.45), concern about violence in the neighbourhood [PR] 2.21; (95%CI 1.48-3.28), discrimination at university [PR] 1.42; (95%CI 1.08-1.86) and food insecurity [PR] 1.45; (95%CI 1.11-1.89) were associated with the presence of poor sleep quality, as well as having less social support and income and suffering psychological distress. The results highlight socioeconomic and mental health factors that affect sleep quality and demonstrate the need for reflection and interventions capable of minimizing this problem.

Sleep troubles in adolescence relate to future initiation of ENDS USE: A longitudinal cohort design using the PATH study waves 4.5–5 (2017–2019)

•

First longitudinal study on the association between sleep trouble and ENDS use.

•

Past year sleep trouble increased risk of initiating ENDS use in following year.

•

Healthy sleep serves as a protective factor against ENDS uptake for youth.

•

Nearly half of youths aged 12–17, experienced sleep troubles during wave 4.5.

•

Sleep classes for youth/delayed school start times may help deter future ENDS use.

In a recent study, we demonstrated a relationship between self-reported sleep deprivation and youth susceptibility to initiate electronic nicotine delivery systems (ENDS) use; however, we were hampered by cross-sectional data. This study builds on our previous work by performing secondary analysis using the nationally representative Population Assessment of Tobacco and Health study datasets from wave 4.5 (2017–2018) and wave 5 (2018–2019) among respondents aged 12–17. Using a longitudinal cohort design, we assessed the extent self-reported sleep troubles at wave 4.5 related to transition from never-to-ever ENDS use by wave 5. We assessed youth who reported never having used any type of tobacco previously and who reported not using alcohol or other illicit substances the previous year. We ran four Poisson regression models on the dependent variable never-to-ever ENDS users at wave 5 and self-reported sleep troubles in the past year at wave 4.5. We controlled for demographic and sociographic factors and, in our final model, tobacco availability in home, exposure to ENDS advertising on social media, past year anxiety, depression, body mass index, physical activity, close friends that use ENDS, perceived harm of ENDS, school performance, sensation seeking, and the susceptibility of youth to initiate ENDS. Even when controlling for these factors, sleep troubles at wave 4.5 significantly and positively related to ENDS initiation by wave 5 (Past year sleep trouble: RR = 1.48 95 % CI = [1.14–1.93]). This key and novel finding has important implications for preventing youth ENDS use via protective self-care and social-environmental approaches.

The roles of the circadian hormone melatonin in drug addiction

Given the devastating social and health consequences of drug addiction and the limitations of current treatments, a new strategy is needed. Circadian system disruptions are frequently associated with drug addiction. Correcting abnormal circadian rhythms and improving sleep quality may thus be beneficial in the treatment of patients with drug addiction. Melatonin, an essential circadian hormone that modulates the biological clock, has anti-inflammatory, analgesic, anti-depressive, and neuroprotective effects via gut microbiota regulation and epigenetic modifications. It has attracted scientists' attention as a potential solution to drug abuse. This review summarized scientific evidence on the roles of melatonin in substance use disorders at the cellular, circuitry, and system levels, and discussed its potential applications as an intervention strategy for drug addiction.

Sleep deprivation and adolescent susceptibility to vaping in the United States

•

Adolescent sleep deprivation is associated with susceptibility to ENDS use.

•

Less than 6 h sleep relates to higher perceived likelihoods of trying ENDS.

•

ENDS prevention efforts may benefit by incorporating sleep hygiene measures.

Sleep deprivation may be a contributing factor to adolescents’ willingness to experiment with substance use, including electronic nicotine devices (ENDS). While it is generally accepted that nicotine has a negative overall effect on sleep, no studies have yet explored whether sleep deprivation may contribute to adolescents’ initiation of ENDS use. The purpose of this study is to explore whether sleep deprivation is associated with adolescents’ self-reported susceptibility to initiating ENDS use in the next month. Respondents were 1,100 adolescents aged 13–17 across the United States who participated in the Vaping Attitudes Youth Perspectives Survey (VAYPS). We used logistic regression to examine cross-sectional associations between self-reported average sleep duration and self-reported likelihood of trying ENDS in the future. Results of the three logistic regression models show that adolescents who reported getting less than six hours of sleep per night were associated with greater odds of reporting any likelihood to try a vape in the next 30 days even when controlling for demographics and potential confounders (<6hrs sleep: OR = 2.63, 95% CI 1.30–5.31). Future research on the association between sleep deprivation and ENDS use among adolescents will benefit from using longitudinal approaches to better understand causality.

Sustained Functioning Impairments and Oxidative Stress with Neurobehavioral Dysfunction Associated with Oral Nicotine Exposure in the Brain of a Murine Model of Ehrlich Ascites Carcinoma: Modifying the Antioxidant Role of Chlorella vulgaris

Simple Summary

Nicotine is the major psychoactive component considered to underlie tobacco’s addictive nature, and its dependence has been linked to several drawbacks on behavior and brain health. The purpose of this study was to investigate the mechanisms triggered by oral nicotine that cause brain tissue damage, as well as the supportive role of Chlorella vulgaris microalgae supplementation in Ehrlich ascites carcinoma in mice. The results revealed pronounced neurobehavioral alterations, increased mortality rate, oxidative stress, DNA damage, and augmented inflammatory response in the brain tissue alongside the microstructural alteration caused by nicotine. Chlorella vulgaris was quite successful in reducing the negative effects of nicotine. It acts as an antioxidant anti-inflammatory and restores nearly normal tissue architectures. As a result, we believe it should be supplemented to cancer patients consuming regular nicotine doses.

Abstract

Background: This study provides a model for studying the mechanism(s) responsible for the nervous tissue damage and misfunctioning that occurred due to oral nicotine exposure, considered a stress factor, during the presence of Ehrlich ascites carcinoma bearing in the mouse model (EAC). The mitigating role of Chlorella vulgaris (CV) against nicotine-induced brain damage was evaluated. Methods: Eighty Swiss female mice were classified into four groups, these were the control, the CV group, the nicotine group(100 µg/kg), and the combination group. Oxidant/antioxidant status, proinflammatory cytokines levels, DNA damage, quantitative microscopical lesions, and Caspase 3, Bcl-2 proteins were assessed in the current study. Levels of dopamine (DA) and gamma-aminobutyric acid (GABA) were also evaluated. Results: Nicotine was found to cause pronounced neurobehavioral alterations, increase the mortalities oxidative stress DNA damage, and augment the inflammatory response in brain tissue alongside the microstructural alteration. The administration of CV with nicotine in EAC-bearing mice rescued the detrimental effects of nicotine. Conclusions: CV aids in reducing the harmful effects of nicotine and returns the conditions caused by nicotine to near-control levels. Thus, we are in favor of giving it to cancer patients who are taking daily dosages of nicotine even by smoking cigarettes or being exposed to second-hand smoke.

Associations between health indicators and sleep duration of American adults: NHANES 2011-16

BACKGROUND

This study aimed to investigate associations between health indicators and sleep duration in the general population.

METHODS

This cross-sectional data from the National Health and Nutrition Examination Survey. Self-reported sleep duration was classified into short sleep (<7 h/day), regular sleep (7-8 h/day) and long sleep duration (>8 h/day). Health indicators included lifestyle indicators (smoking, alcohol use and physical inactivity), general health indicators (waist circumference and self-reported health condition) and chronic conditions [overweight/obesity, hypertension, diabetes, high cholesterol, chronic low back pain (CLBP) and oral health problems]. A series of multinomial logistic regression analysis were performed, controlling for confounders (age, sex, marital status, ethnic background, education level and poverty-to-income ratio).

RESULTS

Data of 12 835 participants were analyzed. The mean (SD) age of participants was 50.0 (±17.4) years, and 50.6% were women. After adjusting for all health indicators, current smoking (OR: 1.37; 95% CI: 1.17-1.61), a poor (OR: 1.52; 95% CI: 1.23-1.88) health condition, CLBP (OR: 1.40; 95% CI: 1.16-1.69) and oral health problems (OR: 1.28; 95% CI: 1.10-1.49) were associated with short sleep duration. No independent association with long sleep duration was observed in this study.

CONCLUSIONS

The results confirm that lifestyle indicators (current smoking and physical inactivity), general health indicators (self-reported health condition) and presence of some chronic conditions (CLBP and oral health problems) are associated with short sleep duration. The results did not confirm that any health indicator was associated with long sleep duration.

Sleeping, Smoking, and Kidney Diseases: Evidence From the NHANES 2017-2018

Study Objectives: Smoking and sleep are modifiable factors associated with the chronic kidney diseases. However, the interaction of smoking and sleep on the renal function are still unclear. Therefore, we aimed to evaluate the interactive impacts of smoking and sleep on the renal function. Methods: Data were obtained from the National Health and Nutrition Examination Survey. The study population were categorized into nine subgroups by smoking (smoking every day, sometimes, and non-smokers recently) and sleep duration (short duration ≤ 6 h, normal duration 6-9 h, and longer duration ≥ 9 h on the weekdays). Results: The study group with a short sleep duration had significantly higher serum cotinine and hydrocotinine levels compared with the other two sleep groups. After adjusting the demographic characteristics (age, race, body mass index, and marital status), sleep quality (snoring or breathing cessation), and comorbidities (diabetes mellitus, hypertension, high cholesterol, anemia, congestive heart failure, coronary heart disease, and stroke), non-smokers with short or long sleep duration had significant lower estimated glomerular filtration rate (eGFR) levels than the study group who smoked every day and slept ≤ 6 h. The effects of sleep duration on eGFR levels varied with smoking status. For the study group smoking every day, eGFR levels increased as sleep duration decreased, whereas for the study group smoking sometimes, eGFR levels increased as sleep duration increased. The U-shaped effects of eGFR levels were observed among non-smokers whose normal sleep duration was associated with better eGFR levels. Normal sleep duration was an important protective factor of the renal function for non-smokers than smokers. Conclusions: The effects of sleep duration on eGFR levels varied with smoking status. Normal sleep duration was a protective factor and more crucial for non-smokers than for smokers.

Smoke at night and sleep worse? The associations between cigarette smoking with insomnia severity and sleep duration

OBJECTIVE

Insomnia is a clinically verified nicotine withdrawal symptom. As nicotine is a stimulant, it is plausible that smoking at night could disturb sleep more than smoking at earlier times of the day, but this remains empirically unclear. This study examined smoking status and its associations with insomnia severity and sleep duration while considering the potential role of smoking time.

METHODS

Data were derived from the Sleep and Healthy Activity Diet Environment and Socialization study, a community-based study of 1007 adults (nnonsmokers = 818; nsmokers = 189) aged 22-60 from the Philadelphia area. Smoking status and time of smoking were self-reported. Insomnia was assessed with the Insomnia Severity Index and categorized as none, mild, and moderate-to-severe. Sleep duration was assessed with one item from the National Health and Nutrition Examination Survey and categorized as very short, short, normal, and long. Ordinal and multinomial logistic regressions were used to determine the association of smoking status including smoking time with insomnia severity and sleep duration controlling for sociodemographic covariates.

RESULTS

Compared to nonsmoking, smoking was associated with experiencing increased insomnia (odds ratio = 2.5, 95% confidence interval [CI] 1.9, 3.4, P < .001) as well as very short (relative risk ratio = 1.9, 95% CI 1.1, 3.3) and short (relative risk ratio = 1.5, 95% CI 1.0, 2.3) sleep (vs normal sleep duration). Night-time smoking was significantly associated with greater insomnia and shorter sleep duration.

CONCLUSIONS

Findings provide evidence that smoking is associated with increased insomnia severity and shorter sleep duration, particularly nightly smoking. Sleep health should be considered in smoking cessation efforts.

Assessing the effect of nicotine dose in cigarette smoking on sleep quality

BACKGROUND

While several studies assessed the relation between cigarette smoking and sleep, there are still very few studies assessing the effect of nicotine in cigarette smoking on sleep.

AIM

This study aimed to compare higher vs lower nicotine levels in cigarette smoking on sleep quality.

METHODS

We used data from the recently released dataset for the Randomized Trial of Reduced-Nicotine Standards for Cigarettes. We included three groups in the current study: the least nicotine concentration (i.e., 0.4 mg/g), a moderate nicotine concentration (i.e., 5.2 mg/g), and the highest nicotine concentration (i.e., 15.8 mg/g). For each participant, we included data regarding baseline and the last follow up at 6 weeks, where we compared insomnia, sleep problems, and awakening at night, in addition to different depression and affect scores.

RESULTS

A total of 360 patients were included in this study, with a mean age of 42.4 (±13.4) years. For the three nicotine groups (i.e., 0.4 mg/g, 5.2 mg/g, and 15.8 mg/g), we included 119 (33%), 122 (34%), and 119 (33%) participants. Among the high-nicotine-dose group, the number of participants who had worsened sleep was significantly higher than the number of those who had improved sleep (p = 0.01) after 6 weeks of consumption, where 37 (31%) had worsened sleep score after 6 weeks while only 19 (16%) had improved score compared with baseline.

CONCLUSION

While previous studies established a relation either between cigarette smoking and sleep or between nicotine patches and sleep, the present study is the first to establish that higher nicotine doses in cigarettes were associated with more sleep disturbances.

The Association of Sleep Duration and the Use of Electronic Cigarettes, NHANES, 2015-2016

Introduction. The unknown effects of electronic cigarettes are public health concerns. One potential effect of electronic cigarette fluid constituents, such as nicotine, may influence sleep. The purpose of this study is to determine if there is an association between sleep duration and electronic cigarette use.

Methods

A retrospective, cross-sectional study was conducted using National Health and Nutrition Examination Survey (NHANES) 2015-2016. Variables of interest included responses to questions concerning electronic cigarette use, hours of sleep, and other variables associated with sleep. Data analyses were conducted with the Rao-Scott chi square test and logistic regression.

Results

This study was conducted on 2889 participants, aged 18-65 years, of whom 50.7% were female. Using a bivariate analyses of electronic cigarette usage and sleep duration, participants who never used an electronic cigarette were more likely to have appropriate sleep durations as compared with participants who were currently using electronic cigarettes (P < 0.0001). After adjusting for sociodemographic variables and cigarette smoking, current electronic cigarette use was associated with higher odds of less sleep duration (adjusted odds ratio = 1.82; 95% CI: 1.18, 2.79; P < 0.0001). After adjusting for sociodemographic variables and cigarette smoking, current electronic cigarette use was associated with higher odds of less sleep duration (adjusted odds ratio = 1.82; 95% CI: 1.18, 2.79.

Conclusions

Participants currently using electronic cigarettes are more likely to have less sleep as compared to participants who have never used electronic cigarettes. Implications. With sleep time duration being a major factor for proper body function and repair, this study can serve as confirmation that the use of electronic cigarettes is not a harmless health behavior.

Home-cage monitoring ascertains signatures of ictal and interictal behavior in mouse models of generalized seizures

Epilepsy is a significant contributor to worldwide disability. In epilepsy, disability can be broadly divided into two components: ictal (pertaining to the burden of unpredictable seizures and associated medical complications including death) and interictal (pertaining to more pervasive debilitating changes in cognitive and emotional behavior). In this study, we objectively and noninvasively appraise aspects of ictal and interictal behavior in mice using instrumented home-cage chambers designed to assay kinematic and appetitive behavioral measures. Through daily intraperitoneal injections of the chemoconvulsant pentylenetetrazole (PTZ) applied to C57BL/6J mice, we coordinately measure how “behavioral severity” (complex dynamic changes in movement and sheltering behavior) and convulsive severity (latency and occurrence of convulsive seizures) evolve or kindle with repeated injections. By closely studying long epochs between PTZ injections, we identify an interictal syndrome of nocturnal hypoactivity and increased sheltering behavior which remits with the cessation of seizure induction. We observe elements of this interictal behavioral syndrome in seizure-prone DBA/2J mice and in mice with a pathogenic Scn1a mutation (modeling Dravet syndrome). Through analyzing their responses to PTZ, we illustrate how convulsive severity and “behavioral” severity are distinct and independent aspects of the overall severity of a PTZ-induced seizure. Our results illustrate the utility of an ethologically centered automated approach to quantitatively appraise murine expressions of disability in mouse models of seizures and epilepsy. In doing so, this study highlights the very unique psychopharmacological profile of PTZ.