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.

• Klíčová slova
• Choroid plexus, Circadian clock, Glucose, Insulin, O-GlcNAc, Restricted feeding, Temperature,
• 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
• Názvy látek
• cirkadiánní proteiny Period MeSH
• Per2 protein, mouse MeSH Prohlížeč

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.

• Klíčová slova
• acylcarnitine, chronodisruption, clock, female, glucose homeostasis, liver, metabolome, pancreas, rat, sleep, suprachiasmatic nucleus,
• 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 * fyziologie   MeSH
• potkani Sprague-Dawley MeSH
• zvířata MeSH
• Check Tag
• krysa rodu Rattus MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• acylcarnitine MeSH Prohlížeč
• karnitin * MeSH

The lifestyle of human society is drifting apart from the natural environmental cycles that have influenced it since its inception. These cycles were fundamental in structuring the daily lives of people in the pre-industrial era, whether they were seasonal or daily. Factors that disrupt the regularity of human behaviour and its alignment with solar cycles, such as late night activities accompanied with food intake, greatly disturb the internal temporal organization in the body. This is believed to contribute to the rise of the so-called diseases of civilization. In this review, we discuss the connection between misalignment in daily (circadian) regulation and its impact on health, with a focus on cardiovascular and metabolic disorders. Our aim is to review selected relevant research findings from laboratory and human studies to assess the extent of evidence for causality between circadian clock disruption and pathology. Keywords: Circadian clock, Chronodisruption, Metabolism, Cardiovascular disorders, Spontaneously hypertensive rat, Human, Social jetlag, Chronotype.

• MeSH
• chronobiologické poruchy patofyziologie   metabolismus   komplikace   MeSH
• cirkadiánní hodiny fyziologie   MeSH
• cirkadiánní rytmus * fyziologie   MeSH
• kardiovaskulární nemoci * metabolismus   etiologie   epidemiologie   patofyziologie   MeSH
• lidé MeSH
• metabolické nemoci * metabolismus   epidemiologie   patofyziologie   etiologie   MeSH
• modely nemocí na zvířatech MeSH
• rizikové faktory MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• přehledy MeSH

Misaligned feeding may lead to pancreatic insufficiency, however, whether and how it affects circadian clock in the exocrine pancreas is not known. We exposed rats to a reversed restricted feeding regimen (rRF) for 10 or 20 days and analyzed locomotor activity, daily profiles of hormone levels (insulin, glucagon, and corticosterone) in plasma, and clock gene expression in the liver and endocrine and exocrine pancreas. In addition, we monitored responses of the exocrine pancreatic clock in organotypic explants of mPer2Luc mice in real time to acetylcholine, insulin, and glucocorticoids. rRF phase-reversed the clock in the endocrine pancreas, similar to the clock in the liver, but completely abolished clock gene rhythmicity and significantly downregulated the expression of Cpb1 and Cel in the exocrine pancreas. rRF desynchronized the rhythms of plasma insulin and corticosterone. Daily profiles of their receptor expression differed in the two parts of the pancreas and responded differently to rRF. Additionally, the pancreatic exocrine clock responded differently to treatments with insulin and the glucocorticoid analog dexamethasone in vitro. Mathematical simulation confirmed that the long-term misalignment between these two hormonal signals, as occurred under rRF, may lead to dampening of the exocrine pancreatic clock. In summary, our data suggest that misaligned meals impair the clock in the exocrine part of the pancreas by uncoupling insulin and corticosterone rhythms. These findings suggest a new mechanism by which adverse dietary habits, often associated with shift work in humans, may impair the clock in the exocrine pancreas and potentially contribute to exocrine pancreatic insufficiency.

• Klíčová slova
• Circadian clock, Dexamethasone, Insulin, Misaligned feeding, Pancreas, mPer2Luc mouse,
• MeSH
• cirkadiánní hodiny * fyziologie   MeSH
• cirkadiánní rytmus fyziologie   MeSH
• glukokortikoidy MeSH
• inzulin metabolismus   MeSH
• kortikosteron metabolismus   farmakologie   MeSH
• krysa rodu Rattus MeSH
• myši MeSH
• pankreas exokrinní * metabolismus   MeSH
• zvířata MeSH
• Check Tag
• krysa rodu Rattus MeSH
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• glukokortikoidy MeSH
• inzulin MeSH
• kortikosteron MeSH

Acetylcholine is an important modulator of striatal activity, and it is vital to controlling striatal-dependent behaviors, including motor and cognitive functions. Despite this significance, the mechanisms determining how acetylcholine impacts striatal signaling are still not fully understood. In particular, little is known about the role of nAChRs expressed by striatal interneurons. In the present study, we used FISH to determine which neuronal types express the most prevalent beta2 nicotinic subunit in the mouse striatum. Our data support a common view that nAChR expression is mostly restricted to striatal interneurons. Surprisingly though, cholinergic interneurons were identified as a population with the highest expression of beta2 nicotinic subunit. To investigate the functional significance of beta2-containing nAChRs in striatal interneurons, we deleted them by injecting the AAV-Cre vector into the striatum of beta2-flox/flox male mice. The deletion led to alterations in several behavioral domains, namely, to an increased anxiety-like behavior, decrease in sociability ratio, deficit in discrimination learning, and increased amphetamine-induced hyperlocomotion and c-Fos expression in mice with beta2 deletion. Further colocalization analysis showed that the increased c-Fos expression was present in both medium spiny neurons and presumed striatal interneurons. The present study concludes that, despite being relatively rare, beta2-containing nAChRs are primarily expressed in striatal neurons by cholinergic interneurons and play a significant role in behavior.SIGNIFICANCE STATEMENT A large variety of nAChRs are expressed in the striatum, a brain region that is crucial in the control of behavior. The complexity of receptors with different functions is hindering our understanding of mechanisms through which striatal acetylcholine modulates behavior. We focused on the role of a small population of beta2-containing nAChRs. We identified neuronal types expressing these receptors and determined their impact in the control of explorative behavior, anxiety-like behavior, learning, and sensitivity to stimulants. Additional experiments showed that these alterations were associated with an overall increased activity of striatal neurons. Thus, the small population of nicotinic receptors represents an interesting target for a modulation of response to stimulant drugs and other striatal-based behavior.

• Klíčová slova
• Fos, acetylcholine, behavior, interneurons, nAChRs, striatum,
• MeSH
• acetylcholin metabolismus   MeSH
• cholinergní látky farmakologie   MeSH
• corpus striatum metabolismus   MeSH
• interneurony metabolismus   MeSH
• myši inbrední C57BL MeSH
• myši MeSH
• nikotinové receptory * metabolismus   MeSH
• zvířata MeSH
• Check Tag
• mužské pohlaví MeSH
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• acetylcholin MeSH
• cholinergní látky MeSH
• nikotinové receptory * MeSH

KEY POINTS: In mammals, the mother-offspring interaction is essential for health later in adulthood. The impact of altered timing and quality of maternal care on the offspring's circadian system was assessed using a cross-strain fostering approach. Better maternal care facilitated the development of amplitudes of Bmal1 clock gene expression in the central clock, as well as the clock-driven activity/rest rhythm, and also its entrainment to the external light/dark cycle. Worse maternal care impaired entrainment of the central clock parameters in the Wistar rat during the early developmental stages. Better maternal care remedied the dampened amplitudes of the colonic clock, as well as cardiovascular functions. The results provide compelling evidence that the circadian phenotype of a foster mother may affect the pathological symptoms of the offspring, even if they are genetically programmed. ABSTRACT: In mammals, the mother-offspring interaction is essential for health later in adulthood. Maternal care is determined by the circadian phenotype of the mother. The impact of altered timing and quality of maternal care on the circadian system was assessed using a cross-strain fostering approach, with 'abnormal' (i.e. circadian misaligned) care being represented by spontaneously hypertensive rats (SHR) and 'normal' care by Wistar rats. The SHR mothers worsened synchrony of the central clock in the suprachiasmatic nuclei with the light/dark cycle in Wistar rat pups, although this effect disappeared after weaning. The maternal care provided by Wistar rat mothers to SHR pups facilitated the development of amplitudes of the Bmal1 expression rhythm in the suprachiasmatic nuclei of the hypothalamus, as well as the clock-driven activity/rest rhythm and its entrainment to the external light/dark cycle. The peripheral clocks in the liver and colon responded robustly to cross-strain fostering; the circadian phenotype of the Wistar rat foster mother remedied the dampened amplitudes of the colonic clock in SHR pups and improved their cardiovascular functions. In general, the more intensive maternal care of the Wistar rat mothers improved most of the parameters of the abnormal SHR circadian phenotype in adulthood; conversely, the less frequent maternal care of the SHR mothers worsened these parameters in the Wistar rat during the early developmental stages. Altogether, our data provide compelling evidence that the circadian phenotype of a foster mother may positively and negatively affect the regulatory mechanisms of various physiological parameters, even if the pathological symptoms are genetically programmed.

• Klíčová slova
• circadian clock, colon, development, heart rate, liver, locomotor activity, maternal care, suprachiasmatic nucleus,
• MeSH
• chování zvířat fyziologie   MeSH
• cirkadiánní hodiny fyziologie   MeSH
• druhová specificita MeSH
• fenotyp MeSH
• mateřské chování fyziologie   MeSH
• novorozená zvířata MeSH
• nucleus suprachiasmaticus fyziologie   MeSH
• potkani inbrední SHR MeSH
• potkani Wistar MeSH
• zvířata MeSH
• Check Tag
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

The McGill-R-Thy1-APP transgenic rat is an animal model of the familial form of Alzheimer's disease (AD). This model mirrors several neuropathological hallmarks of the disease, including the accumulation of beta-amyloid and the formation of amyloid plaques (in homozygous animals only), neuroinflammation and the gradual deterioration of cognitive functions even prior to plaque formation, although it lacks the tauopathy observed in human victims of AD. The goal of the present study was a thorough characterization of the homozygous model with emphasis on its face validity in several domains of behavior known to be affected in AD patients, including cognitive functions, motor coordination, emotionality, sociability, and circadian activity patterns. On the behavioral level, we found normal locomotor activity in spontaneous exploration, but problems with balance and gait coordination, increased anxiety and severely impaired spatial cognition in 4-7 month old homozygous animals. The profile of social behavior and ultrasonic communication was altered in the McGill rats, without a general social withdrawal. McGill rats also exhibited changes in circadian profile, with a shorter free-running period and increased total activity during the subjective night, without signs of sleep disturbances during the inactive phase. Expression of circadian clock gene Bmal1 was found to be increased in the parietal cortex and cerebellum, while Nr1d1 expression was not changed. The clock-controlled gene Prok2 expression was found to be elevated in the parietal cortex and hippocampus, which might have contributed to the observed changes in circadian phenotype. We conclude that the phenotype in the McGill rat model is not restricted to the cognitive domain, but also includes gait problems, changes in emotionality, social behavior, and circadian profiles. Our findings show that the model should be useful for the development of new therapeutic approaches targeting not only memory decline but also other symptoms decreasing the quality of life of AD patients.

• Klíčová slova
• Alzheimer's disease, amyloid precursor protein, circadian system, cognition, rat, social behavior, transgenic,
• Publikační typ
• časopisecké články MeSH