The circadian clock in choroid plexus (ChP) controls processes involved in its physiological functions, but the signals that synchronize the clock have been sparsely studied. We found that the ChP clock in the fourthventricle (4V) is more robust than that in the lateral ventricle (LV) and investigated whether both clocks use information about mealtime as a signal to synchronize with the current activity state. Exposure of mPer2Luc mice to a 10-day reverse restricted feeding (rRF) protocol, in which food was provided for 6 h during daytime, advanced the phase of the ChP clock in 4V and LV, as evidenced by shifted (1) PER2-driven bioluminescence rhythms of ChP explants ex vivo and (2) daily profiles in clock gene expression in both ChP tissues in vivo. In contrast, clocks in other brain regions (DMH, ARC, LHb) of the same mice did not shift. The 4V ChP responded more strongly than the LV ChP to rRF by modulating the expression of genes to ensure a decrease in resistance to cerebrospinal fluid drainage and increase the secretory capacity of ChP cells. Mechanistically, rRF affects the ChP clock through food-induced increases in insulin, glucose and temperature levels, as in vitro all three signals significantly shifted the clocks in both ChP tissues, similar to rRF. The effect of glucose was partially blocked by OSMI-1, suggesting involvement of O-linked N-acetylglucosamine posttranslational modification. We identified mechanisms that can signal to the brain the time of feeding and the associated activity state via resetting of the ChP clock.
- MeSH
- cirkadiánní hodiny * fyziologie genetika MeSH
- cirkadiánní proteiny Period metabolismus genetika MeSH
- cirkadiánní rytmus fyziologie MeSH
- myši inbrední C57BL MeSH
- myši transgenní MeSH
- myši MeSH
- plexus chorioideus * metabolismus fyziologie MeSH
- regulace genové exprese MeSH
- stravovací zvyklosti * fyziologie MeSH
- ventriculi laterales metabolismus fyziologie MeSH
- zvířata MeSH
- Check Tag
- mužské pohlaví MeSH
- myši MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
AIM: Exposure to light at night and meal time misaligned with the light/dark (LD) cycle-typical features of daily life in modern 24/7 society-are associated with negative effects on health. To understand the mechanism, we developed a novel protocol of complex chronodisruption (CD) in which we exposed female rats to four weekly cycles consisting of 5-day intervals of constant light and 2-day intervals of food access restricted to the light phase of the 12:12 LD cycle. METHODS: We examined the effects of CD on behavior, estrous cycle, sleep patterns, glucose homeostasis and profiles of clock- and metabolism-related gene expression (using RT qPCR) and liver metabolome and lipidome (using untargeted metabolomic and lipidomic profiling). RESULTS: CD attenuated the rhythmic output of the central clock in the suprachiasmatic nucleus via Prok2 signaling, thereby disrupting locomotor activity, the estrous cycle, sleep patterns, and mutual phase relationship between the central and peripheral clocks. In the periphery, CD abolished Per1,2 expression rhythms in peripheral tissues (liver, pancreas, colon) and worsened glucose homeostasis. In the liver, it impaired the expression of NAD+, lipid, and cholesterol metabolism genes and abolished most of the high-amplitude rhythms of lipids and polar metabolites. Interestingly, CD abolished the circadian rhythm of Cpt1a expression and increased the levels of long-chain acylcarnitines (ACar 18:2, ACar 16:0), indicating enhanced fatty acid oxidation in mitochondria. CONCLUSION: Our data show the widespread effects of CD on metabolism and point to ACars as biomarkers for CD due to misaligned sleep and feeding patterns.
- MeSH
- cirkadiánní hodiny fyziologie MeSH
- cirkadiánní rytmus * fyziologie MeSH
- fotoperioda MeSH
- játra * metabolismus MeSH
- karnitin * analogy a deriváty metabolismus MeSH
- krysa rodu rattus MeSH
- metabolom * MeSH
- nucleus suprachiasmaticus metabolismus MeSH
- zvířata MeSH
- Check Tag
- krysa rodu rattus MeSH
- ženské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
Choroid plexus (ChP), the brain structure primarily responsible for cerebrospinal fluid production, contains a robust circadian clock, whose role remains to be elucidated. The aim of our study was to [1] identify rhythmically controlled cellular processes in the mouse ChP and [2] assess the role and nature of signals derived from the master clock in the suprachiasmatic nuclei (SCN) that control ChP rhythms. To accomplish this goal, we used various mouse models (WT, mPer2Luc, ChP-specific Bmal1 knockout) and combined multiple experimental approaches, including surgical lesion of the SCN (SCNx), time-resolved transcriptomics, and single cell luminescence microscopy. In ChP of control (Ctrl) mice collected every 4 h over 2 circadian cycles in darkness, we found that the ChP clock regulates many processes, including the cerebrospinal fluid circadian secretome, precisely times endoplasmic reticulum stress response, and controls genes involved in neurodegenerative diseases (Alzheimer's disease, Huntington's disease, and frontotemporal dementia). In ChP of SCNx mice, the rhythmicity detected in vivo and ex vivo was severely dampened to a comparable extent as in mice with ChP-specific Bmal1 knockout, and the dampened cellular rhythms were restored by daily injections of dexamethasone in mice. Our data demonstrate that the ChP clock controls tissue-specific gene expression and is strongly dependent on the presence of a functional connection with the SCN. The results may contribute to the search for a novel link between ChP clock disruption and impaired brain health.
- MeSH
- cirkadiánní hodiny * fyziologie MeSH
- cirkadiánní rytmus fyziologie MeSH
- myši inbrední C57BL MeSH
- myši knockoutované MeSH
- myši MeSH
- nucleus suprachiasmaticus * metabolismus fyziologie MeSH
- plexus chorioideus * metabolismus fyziologie MeSH
- transkripční faktory ARNTL metabolismus genetika MeSH
- zvířata MeSH
- Check Tag
- mužské pohlaví MeSH
- myši MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
The topic of human circadian rhythms is not only attracting the attention of clinical researchers from various fields but also sparking a growing public interest. The circadian system comprises the central clock, located in the suprachiasmatic nucleus of the hypothalamus, and the peripheral clocks in various tissues that are interconnected; together they coordinate many daily activities, including sleep and wakefulness, physical activity, food intake, glucose sensitivity and cardiovascular functions. Disruption of circadian regulation seems to be associated with metabolic disorders (particularly impaired glucose tolerance) and cardiovascular disease. Previous clinical trials revealed that disturbance of the circadian system, specifically due to shift work, is associated with an increased risk of type 2 diabetes mellitus. This review is intended to provide clinicians who wish to implement knowledge of circadian disruption in diagnosis and strategies to avoid cardio-metabolic disease with a general overview of this topic.
- MeSH
- chronobiologické poruchy patofyziologie komplikace MeSH
- cirkadiánní rytmus * fyziologie MeSH
- diabetes mellitus 2. typu patofyziologie metabolismus MeSH
- kardiovaskulární nemoci * etiologie patofyziologie MeSH
- lidé MeSH
- metabolické nemoci * patofyziologie metabolismus etiologie MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- přehledy MeSH
The choroid plexus (ChP) in the brain ventricles has a major influence on brain homeostasis. In this study, we aimed to determine whether the circadian clock located in ChP is affected by chronodisruption caused by misalignment with the external light/dark cycle and/or inflammation. Adult mPer2Luc mice were maintained in the LD12:12 cycle or exposed to one of two models of chronic chronodisruption - constant light for 22-25 weeks (cLL) or 6-hour phase advances of the LD12:12 cycle repeated weekly for 12 weeks (cLD-shifts). Locomotor activity was monitored before the 4th ventricle ChP and suprachiasmatic nuclei (SCN) explants were recorded in real time for PER2-driven population and single-cell bioluminescence rhythms. In addition, plasma immune marker concentrations and gene expression in ChP, prefrontal cortex, hippocampus and cerebellum were analyzed. cLL dampened the SCN clock but did not shorten the inactivity interval (sleep). cLD-shifts had no effect on the SCN clock, but transiently affected sleep duration and fragmentation. Both chronodisruption protocols dampened the ChP clock. Although immune markers were elevated in plasma and hippocampus, levels in ChP were unaffected, and unlike the liver clock, the ChP clock was resistant to lipopolysaccharide treatment. Importantly, both chronodisruption protocols reduced glucocorticoid signaling in ChP. The data demonstrate the high resistance of the ChP clock to inflammation, highlighting its role in protecting the brain from neuroinflammation, and on the other hand its high sensitivity to chronodisruption. Our results provide a novel link between human lifestyle-induced chronodisruption and the impairment of ChP-dependent brain homeostasis.
- MeSH
- chronická lymfatická leukemie * MeSH
- cirkadiánní hodiny * MeSH
- cirkadiánní proteiny Period genetika metabolismus MeSH
- cirkadiánní rytmus fyziologie MeSH
- lidé MeSH
- myši MeSH
- plexus chorioideus metabolismus MeSH
- zánět MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- myši MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
STUDY OBJECTIVES: Social jetlag manifests as a difference in sleep timing on workdays and free days. Social jetlag is often associated with shorter, lower-quality sleep, so it is unclear how much the chronic circadian misalignment contributes to observed negative health outcomes. We aimed to (1) investigate associations between social jetlag, chronotype (one of its determinants), and the levels of health markers, (2) describe factors associated with social jetlag, and (3) examine whether working from home can reduce social jetlag. METHODS: Adult respondents participated in a nationally representative longitudinal survey of Czech households (individuals in each wave: n2018/19/20 = 5132/1957/1533), which included Munich ChronoType Questionnaire to evaluate chronotype and social jetlag. A subset provided blood samples (n2019 = 1957) for detection of nine biomarkers and was surveyed in three successive years (social jetlag calculated for n2018/19/20 = 3930/1601/1237). Data were analyzed by nonparametric univariate tests and mixed effects multivariate regression with social jetlag, chronotype, sex, age, body-mass index, and reported diseases as predictors and biomarker levels as outcomes. RESULTS: Higher social jetlag (≥0.65 h) was significantly associated with increased levels of total cholesterol and low-density lipoprotein cholesterol, particularly in participants older than 50 years (Mann-Whitney, men: pCHL = 0.0005, pLDL = 0.0009; women: pCHL = 0.0079, pLDL = 0.0068). Extreme chronotypes were associated with cardiovascular disease risk markers regardless of social jetlag (Kruskal-Wallis, p < 0.0001). Commuting to work and time stress were identified as important contributors to social jetlag. Individual longitudinal data showed that working from home decreased social jetlag and prolonged sleep. CONCLUSIONS: We report significant associations between sleep phase preference, social jetlag, and cardio-metabolic biomarkers.
- MeSH
- biologické markery MeSH
- cholesterol MeSH
- cirkadiánní rytmus * MeSH
- dospělí MeSH
- jet lag syndrom MeSH
- lidé MeSH
- metabolické nemoci * komplikace MeSH
- průzkumy a dotazníky MeSH
- spánek MeSH
- Check Tag
- dospělí MeSH
- lidé MeSH
- mužské pohlaví MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Lithium is an effective mood stabilizer, but the mechanism of its therapeutic action is not well understood. We investigated the effect of lithium on the circadian clock located in the ventricle barrier complex containing the choroid plexus (CP), a part of the glymphatic system that influences gross brain function via the production of cerebrospinal fluid. The mPer2Luc mice were injected with lithium chloride (LiCl) or vehicle, and their effects on the clock gene Nr1d1 in CP were detected by RT qPCR. CP organotypic explants were prepared to monitor bioluminescence rhythms in real time and examine the responses of the CP clock to LiCl and inhibitors of glycogen synthase kinase-3 (CHIR-99021) and protein kinase C (chelerythrine). LiCl affected Nr1d1 expression levels in CP in vivo and dose-dependently delayed the phase and prolonged the period of the CP clock in vitro. LiCl and CHIR-99021 had different effects on 1] CP clock parameters (amplitude, period, phase), 2] dexamethasone-induced phase shifts of the CP clock, and 3] dynamics of PER2 degradation and de novo accumulation. LiCl-induced phase delays were significantly reduced by chelerythrine, suggesting the involvement of PKC activity. The effects on the CP clock may be involved in the therapeutic effects of lithium and hypothetically improve brain function in psychiatric patients by aligning the function of the CP clock-related glymphatic system with the sleep-wake cycle. Importantly, our data argue for personalized timing of lithium treatment in BD patients.
- MeSH
- cirkadiánní hodiny * MeSH
- cirkadiánní proteiny Period genetika MeSH
- cirkadiánní rytmus genetika MeSH
- lithium farmakologie MeSH
- myši MeSH
- plexus chorioideus metabolismus MeSH
- zvířata MeSH
- Check Tag
- myši MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
