PER2 Research Articles

Metabolic Effects of Light at Night are Time- and Wavelength-Dependent in Rats.

ObjectiveIntrinsically photosensitive retinal ganglion cells are most sensitive to short wavelengths and reach brain regions that modulate biological rhythms and energy metabolism. The increased exposure nowadays to artificial light at night (ALAN), especially short wavelengths, perturbs our synchronization with the 24‐hour solar cycle. Here, the time‐ and wavelength dependence of the metabolic effects of ALAN are investigated.MethodsMale Wistar rats were exposed to white, blue, or green light at different time points during the dark phase. Locomotor activity, energy expenditure, respiratory exchange ratio (RER), and food intake were recorded. Brains, livers, and blood were collected.ResultsAll wavelengths decreased locomotor activity regardless of time of exposure, but changes in energy expenditure were dependent on the time of exposure. Blue and green light reduced RER at Zeitgeber time 16‐18 without changing food intake. Blue light increased period 1 (Per1) gene expression in the liver, while green and white light increased Per2. Blue light decreased plasma glucose and phosphoenolpyruvate carboxykinase (Pepck) expression in the liver. All wavelengths increased c‐Fos activity in the suprachiasmatic nucleus, but blue and green light decreased c‐Fos activity in the paraventricular nucleus.ConclusionsALAN affects locomotor activity, energy expenditure, RER, hypothalamic c‐Fos expression, and expression of clock and metabolic genes in the liver depending on the time of day and wavelength.

Expression of circadian clock genes during differentiation of rat dental papilla cells in vitro

ABSTRACT The circadian clock is involved in many physiological processes including teeth development. The expression of circadian core clock genes was observed in various tissues, but their role in odontoblasts is unclear. The aim of this study was to investigate the circadian core clock gene expressions of dental papilla cells (DPCs) during the odontogenic differentiation. Primary DPCs were obtained from the first molar dental papilla of neonatal rats and cultured in osteogenic (OS) medium for differentiation in vitro. Reverse transcription and quantitative PCR was performed to assess the mRNA levels of the circadian core clock genes Bmal1, Per2, Cry1, Clock, Rev-erb α and Ror α. Western blotting was performed to assess the protein levels of BMAL1 and PER2. The results showed that apparent oscillatory expression patterns of Per2, Cry1, Rev-erb α could be observed in DPCs, whether differentiated or not. The protein level of BMAL1 was significantly increased and PER2 was decreased during odontogenic differentiation. Taken together, these findings demonstrate that circadian rhythmicity of known core clock genes exist in cultured DPCs in vitro, and the expression of genes change during differentiation process.

Perinatal fluoxetine exposure disrupts the circadian response to a phase-shifting challenge in female rats

RationaleSelective serotonin reuptake inhibitor (SSRI) antidepressants are increasingly prescribed during pregnancy. Changes in serotonergic signaling during human fetal development have been associated with changes in brain development and with changes in affective behavior in adulthood. The suprachiasmatic nucleus (SCN) is known to be modulated by serotonin and it is therefore assumed that SSRIs may affect circadian rhythms. However, effects of perinatal SSRI treatment on circadian system functioning in the offspring are largely unknown.ObjectiveOur aim was to investigate the effects of perinatal exposure to the SSRI fluoxetine (FLX) on circadian behavior, affective behavior, and 5-HT1A receptor sensitivity in female rats. In addition, we studied the expression of clock genes and the 5-HT1A receptor in the SCN, as they are potentially involved in underlying mechanisms contributing to changes in circadian rhythms.ResultsPerinatal FLX exposure shortened the free-running tau in response to the 5-HT1A/7 agonist 8-OH-DPAT. However, FLX exposure did not alter anxiety, stress coping, and 5-HT1A receptor sensitivity. No differences were found in 5-HT1A receptor and clock genes Per1, Per2, Cry1, and Cry2 SCN gene expression.ConclusionsPerinatal FLX exposure altered the response to a phase-shifting challenge in female rats, whether this may pose health risks remains to be investigated.

Comparing expression levels of PERIOD genes PER1, PER2 and PER3 in chronic insomnia patients and medical staff working in the night shift

AimThis study was done to determine the changes in expression levels of PERIOD family genes in chronic insomnia patients and night shift healthcare staff with irregular sleep hours. MethodA total of 24 chronic insomnia patients aged between 25 and 55 that were admitted to Erciyes University Medical Faculty Neurology Polyclinic, 32 medical staff aged between 23 and 42 that work in night shifts with no neurological diagnosis were included as volunteers in the experiment. Additionally, a control group consisting of 29 healthy individuals between 21 and 50 years of age who do not work in shifts was volunteered in the study. Since PERIOD family gene expressions are affected by time of day and season changes, blood samples were taken from the groups within the same week and at the same time periods. RNA isolation followed by cDNA synthesis from leukocytes was performed from blood samples that were kept in 10 cc EDTA tubes. Expression levels of the genes were then determined by quantitative PCR method and analysed. ResultsThere was a significant decrease in the expression levels of PER1 and PER2 genes in chronic insomnia and night shift healthcare professional groups compared to the control group (p = 0.0001 for PER1; p = 0.0023 for PER2), but no significant change was observed in PER3 gene (p = 0.619). DiscussionThe decrease in PER1 and PER2 gene expressions in chronic insomnia and shift working healthcare personnel seems to be more of a result for short sleep periods than a cause.

Effects of Occupational Stress and Circadian CLOCK Gene Polymorphism on Sleep Quality of Oil Workers in Xinjiang, China.

BackgroundThis study investigated the effect of occupational stress and circadian clock gene polymorphism on sleep disorder of oil workers in Xinjiang, China.Material/MethodsWe enrolled 2300 Xinjiang oil workers who had been working for at least 1 year. The Chinese revised version of the Occupational Stress Questionnaire (OSI-R), the Pittsburgh Sleep Quality Index (PSQI), and General Survey Questionnaire were used. A total of 308 subjects were selected for stress hormone measurements and gene polymorphism analysis of the circadian clock genes CLOCK, PER2, and PER3.ResultsThe occupational stress scores were influenced by sex, smoking, marital status, age, and work type. Different work shift groups and different professional title groups had statistically significant sleep disorder incidences (P<0.05). The middle and high occupational stress groups had significantly higher subjective sleep quality, total PSQI scores, daytime dysfunction factor scores, and sleep disorder than in the low occupational stress group (P<0.05). CLOCK gene rs1801260 locus carrying TC genotype (OR=0.412, 95% CI=0.245–0.695), and CLOCK gene rs6850524 locus carrying GC and CC genotypes decreased sleep disorder risk (OR1=0.357, 95% CI1=0.245–0.695; OR2=0.317, 95% CI2=0.128–0.785). The main factors affecting the sleep quality of oil workers were length of service, individual strain capacity, glucocorticoid levels, Per3 gene, and the rs6850524 loci of CLOCK gene.ConclusionsOccupational stress has an adverse effect on the sleep quality of workers. CLOCK gene and Per3 gene may increase risk of sleep disorders.

Downregulation of PER2 Promotes Tumor Progression by Enhancing Glycolysis via the Phosphatidylinositol 3-Kinase/Protein Kinase B Pathway in Oral Squamous Cell Carcinoma

PER2 gene expression is downregulated in oral squamous cell carcinoma (OSCC) and may have a pivotal role in tumor suppression. However, the biological function and mechanism of action of PER2 in OSCC remain unclear. In this study, the biological functions and anticancer mechanisms of PER2 in OSCC were investigated. Both stably overexpressed and silenced PER2 OSCC cells were established as an experimental group; empty vector lentivirus and scramble short hairpin RNA lentivirus transfected-cells, as negative control groups; and untreated OSCC cells, as a blank group.Cell proliferation, apoptosis, and glycolysis potential assays were conducted. In addition, the expression of phosphatidylinositol 3-kinase (PI3K), protein kinase B (AKT), phosphorylation of protein kinase B, hexokinase 2 (HK2), pyruvate kinase M (PKM2), and lactate dehydrogenase A (LDHA) was quantified by real-time quantitative polymerase chain reaction and Western blotting.Rescue experiments were performed by the addition of AKT activators in the overexpressed cell line and by the addition of glycolysis inhibitor in the silenced cell line. These findings were verified invivo using stably transfected OSCC cells overexpressing PER2 implanted in nude mice. PER2 overexpression significantly inhibited OSCC cell proliferation and glycolysis, promoted cell apoptosis, and reduced the expression of PI3K, phosphorylation of protein kinase B, HK2, PKM2, and LDHA. The converse was observed in PER2-silenced OSCC cells. After the addition of AKT activator to cultures of PER2-overexpressed OSCC cells, reduced glucose uptake, lactic acid production, and cell proliferation, combined with increased apoptosis, were substantially reversed. In addition, after the addition of HK2 inhibitor to PER2-silenced OSCC cells to inhibit glycolysis, the reduction in apoptosis and increased proliferation were significantly countermanded. Tumorigenesis experiments invivo also confirmed that PER2 overexpression suppressed OSCC growth and decreased the expression of HK2, PKM2, and LDHA. PER2 heightened glycolysis via the PI3K/AKT pathway, heightened cell proliferation and inhibited apoptosis via glycolysis, thereby promoting the development of OSCC.

Comparative Assessment of the Immunologic and Genetic Status of Children Living in the Far North and the Perm Region

Introduction: Life at high latitudes imbalances immuno-neuro-endocrine regulation in humans due to contrasting changes in the duration of the light period. Our objective was to study the immune and genetic status of children living in the Far North and the Perm Region. Materials and methods: We conducted a survey of 120 children of 3 to 12 living in the Far North, and 154 children of 7 to 18 living in the Perm Region with a normal alternation of day and night. In order to study the frequency of the PER2 circadian gene polymorphism (C/G, rs643159) a genetic analysis was performed by real-time PCR with a subsequent allelic discrimination. Results: The comparative analysis of the frequencies of alleles and genotypes of the PER2 clock gene polymorphism (rs643159) showed no significant differences in its polymorphism in the children's groups differing in climatic features. The results of an immunological study of the blood of children in the Arctic enabled us to establish changes in the immune status characterized by a significant (p &lt; 0.05) decrease in class A immunoglobulins (1.26 times), M (1.14 times), G (1.15 times), mediators of neuroendocrine regulation of cortisol (1.33 times), serotonin (1.42 times), as well as overproduction of apoptosis activator CD3+CD95+ and TSH relative to the child contingent of Prikamye (p &lt; 0.05). Conclusions: The comparative analysis of the status of regulatory mediators in the children living in the Far North with similar indicators of the child contingent of moderate latitudes (the Perm Region) – carriers of the mutant G allele of the clock receptor gene allowed us to establish not only a reliable imbalance in the immune status in children living under conditions of asynchronosis but also a significant deficit of the regulatory mediator of serotonin free T4 and increased levels of cortisol (p &lt; 0.05) characterizing the breakdown of neuroregulatory connections. Thus, in the conditions of the Far North the imbalance of key indicators of immune homeostasis, neuroendocrine regulation, associated with the variant G allele of the gene PER2 (rs643159) is formed.

Low circadian clock genes expression in cancers: A meta-analysis of its association with clinicopathological features and prognosis.

BackgroundPer1, Per2, Per3, Cry1, Cry2, Bmal1, Npas2 and CLOCK genes are the eight core circadian clock genes. Low expression of these circadian clock genes plays an important role in the progression of cancers. However, its clinicopathological and prognostic value in patients with cancers remains controversial and inconclusive. We performed a meta-analysis of studies assessing the clinicopathological and prognostic significance of low expression of these genes in cancers.MethodsRelevant studies were searched from the Cochrane Central Register of Controlled Trials, Embase, EBSCO, Ovid, PubMed, Science Direct, Wiley Online Library database, CNKI and Wan Fang database. The meta-analysis was performed by using STATA version 12 software. A random-effect model was employed to evaluate all pooled hazard ratios (HRs) and odd ratios (ORs).ResultsA total of 36 studies comprising 7476 cases met the inclusion criteria. Meta-analysis suggested that low expression of Per1 was associated with poor differentiation (Per1: OR=2.30, 95%CI: 1.36∼3.87, P=0.002) and deeper invasion depth (Per1: OR=2.12, 95%CI: 1.62∼2.77, Ρ<0.001); low Per2 expression was correlated with poor differentiation (Per2: OR=2.41, 95%CI: 1.53∼3.79, Ρ<0.001), worse TNM stage (Per2:OR=3.47, 95%CI: 1.88∼6.42, P<0.001) and further metastasis (Per2:OR=2.35, 95%CI: 1.35∼4.11, Ρ=0.003). Furthermore, the results revealed that low expressions of Per1 and Per2 were also correlated with poor overall survival of cancers (Per1: HR=1.35, 95%CI: 1.06∼1.72, P=0.014; Per2: HR=1.43, 95%CI: 1.10∼1.85, P=0.007). Subgroup analysis indicated that low Per1 and Per2 expressions were especially associated with poor prognosis of gastrointestinal caners (Per1: HR=1.33, 95%CI: 1.14∼1.55, Ρ<0.001, Ι2=4.2%; Per2: HR=1.62, 95%CI: 1.25∼2.18, P<0.001, I2=0.0%).ConclusionsOur study suggested that low Per1, Per2 and Npas2 expression played a distinct and crucial role in progression of cancers. Low expressions of Per1 and Per2 could serve as unfavorable indicators for cancers prognosis, especially for gastrointestinal cancers.

Interaction of alcohol with time of eating on markers of circadian dyssynchrony and colon tissue injury

BackgroundAlcohol increases the risk of developing colon cancer (CRC), in part via tissue inflammation and impaired barrier integrity. Circadian dyssynchrony (CD) is an understudied but common lifestyle associated factor that increases the risk of multi-organ tissue injury and number of malignancies including CRC. Our prior studies showed that the shift in light-dark cycle exacerbates barrier dysfunction and colonic inflammation in the setting of alcohol treatment, and increases the risk of CRC. Here we studied the interaction of alcohol with an abnormal eating pattern on markers of CD and colonic barrier integrity. MethodMice were subjected to day (rest-phase = wrong-time WT) or night-time (active-phase = right-time RT) access to food in combination with access to water or 15% alcohol for total duration of 10 weeks. The food and liquid intake was measured. The locomotor activity data was recorded throughout the study, using a beam-break system. Mice were euthanized at two time points (ZT2 and ZT14). Time variation in the expression of the molecular marker of circadian clock (per2 gene) was measured in the central (hypothalamus) and intestinal (colon) tissue. Colonic protein expression of barrier markers (Occludin and Claudin-1) was studied. ResultsNo significant differences were present in the weight gain and alcohol intake among the groups over the study period. We observed an interaction of WT eating with alcohol on behavioral markers of circadian rhythm. Compared to the RT + Water treated animals (“reference group”), combination of WT eating and alcohol consumption (WT + Alcohol) significantly changed the per2 oscillatory pattern, that was different between the colon and hypothalamus, indicative of worsening circadian dyssynchrony. This was associated with an overall impaired expression of barrier integrity markers in the colon. ConclusionsAlcohol induces circadian dyssynchrony which is worsened by abnormal food timing, associated with impaired barrier integrity in the colon. Future studies on the interaction of alcohol and food timing could provide further insights into alcohol associated CRC pathophysiology.

Altered light induced EGR1 expression in the SCN of PACAP deficient mice.

The brain's biological clock is located in the suprachiasmatic nucleus (SCN) of the hypothalamus and generates circadian rhythms in physiology and behavior. The circadian clock needs daily adjustment by light to stay synchronized (entrained) with the astronomical 24 h light/dark cycle. Light entrainment occurs via melanopsin expressing retinal ganglion cells (mRGCs) and two neurotransmitters of the retinohypothalamic tract (RHT), PACAP and glutamate, which transmit light information to the SCN neurons. In SCN neurons, light signaling involves the immediate-early genes Fos, Egr1 and the clock genes Per1 and Per2. In this study, we used PACAP deficient mice to evaluate PACAP's role in light induced gene expression of EGR1 in SCN neurons during early (ZT17) and late (ZT23) subjective night at high (300 lux) and low (10 lux) white light exposure. We found significantly lower levels of both EGR1 mRNA and protein in the SCN in PACAP deficient mice compared to wild type mice at early subjective night (ZT17) exposed to low but not high light intensity. No difference was found between the two genotypes at late night (ZT23) at neither light intensities. In conclusion, light mediated EGR1 induction in SCN neurons at early night at low light intensities is dependent of PACAP signaling. A role of PACAP in shaping synaptic plasticity during light stimulation at night is discussed.

The Role of Circadian Clock Period 2 (per 2) gene and the expression of per2 related gene in atopic dermatitis animal model

Abstract Atopic dermatitis is a chronic, inflammatory skin disorder associated with defective skin barrier and epidermal hyper reactivity. AD is a Th2 mediated allergic disease. GATA3 is a transcription factor that plays an important role in Th2 differentiation. In this study we investigated the per2 gene role and the expression of per2 related genes in atopic dermatitis. We established the atopic dermatitis animal model in per2 knock out and C57BL/6 by 2,4-dinitrochlorobenzene (DNCB). A subset of mice in both per2 knock out and C57BL/6 were treated with saline as control group. The skin lesions severity score was alleviated in per2 knock out mice DNCB group than wild type group. We examined the TNF-α mRNA expression in skin samples that showed that per2 knock out mice protected from DNCB induced inflammation than wild type mice. We next examined BMAL1 mRNA expression in skin samples that showed BMAL1 functioned as anti-inflammatory molecule in per2 knock out mice and levels are high than wild type mice and GATA3 expression levels were not initiated in per2 knock out mice than wild type mice. According to these results we hypothesized per2 knock out mice protected from allergic atopic dermatitis by increasing anti-inflammatory molecule BMAL1 through supressing GATA3.

Circadian clock genes and respiratory neuroplasticity genes oscillate in the phrenic motor system.

Circadian rhythms are endogenous and entrainable daily patterns of physiology and behavior. Molecular mechanisms underlie circadian rhythms, characterized by an ~24-h pattern of gene expression of core clock genes. Although it has long been known that breathing exhibits circadian rhythms, little is known concerning clock gene expression in any element of the neuromuscular system controlling breathing. Furthermore, we know little concerning gene expression necessary for specific respiratory functions, such as phrenic motor plasticity. Thus, we tested the hypotheses that transcripts for clock genes (Bmal1, Clock, Per1, and Per2) and molecules necessary for phrenic motor plasticity (Htr2a, Htr2b, Bdnf, and Ntrk2) oscillate in regions critical for phrenic/diaphragm motor function via RT-PCR. Tissues were collected from male Sprague-Dawley rats entrained to a 12-h light-dark cycle at 4 zeitgeber times (ZT; n = 8 rats/group): ZT5, ZT11, ZT17, and ZT23; ZT0 = lights on. Here, we demonstrate that 1) circadian clock genes (Bmal1, Clock, Per1, and Per2) oscillate in regions critical for phrenic/diaphragm function, including the caudal medulla, ventral C3-C5 cervical spinal cord, and diaphragm; 2) the clock protein BMAL1 is localized within CtB-labeled phrenic motor neurons; 3) genes necessary for intermittent hypoxia-induced phrenic/diaphragm motor plasticity (Htr2b and Bdnf) oscillate in the caudal medulla and ventral C3-C5 spinal cord; and 4) there is higher intensity of immunofluorescent BDNF protein within phrenic motor neurons at ZT23 compared with ZT11 (n = 11 rats/group). These results suggest local circadian clocks exist in the phrenic motor system and confirm the potential for local circadian regulation of neuroplasticity and other elements of the neural network controlling breathing.

The clock-controlled chemokine contributes to neuroinflammation-induced depression.

The circadian rhythm plays a central role in immune function, and its disruption has been closely linked to the etiology of depression. However, the mechanisms underlying the association between depression and circadian rhythm remain unclear. We found that mice deficient of Per2, a central clock component of circadian output, were resilient to neuroinflammation-induced depressive behavior. After repeated central lipopolysaccharide (LPS) injections, MCP-1, MIP-1β, and RANTES increased in wild type (WT) but not in Per2-deficient mice. In addition, intracerebroventricular injection of RANTES resulted in depression-like behavior, and Met-RANTES, a CCR5 antagonist, could reverse depression-like behavior induced by LPS treatments. These results indicated that the Per2 gene contributes to depression via chemokines, especially RANTES. Furthermore, BMAL1 expression decreased in LPS-treated Per2-deficient mice and BMAL1 could bind to the promoter of Rantes, indicating clock gene can act as a regulator for neuroinflammation. In conclusion, Rantes, a clock-controlled gene (CCG), is involved in clock-immunological mechanisms underlying the effects of Per2 on neuroinflammation-induced depression-like behavior.

The Core-Clock Gene NR1D1 Impacts Cell Motility In Vitro and Invasiveness in A Zebrafish Xenograft Colon Cancer Model.

Malfunctions of circadian clock trigger abnormal cellular processes and influence tumorigenesis. Using an in vitro and in vivo xenograft model, we show that circadian clock disruption via the downregulation of the core-clock genes BMAL1, PER2, and NR1D1 impacts the circadian phenotype of MYC, WEE1, and TP53, and affects proliferation, apoptosis, and cell migration. In particular, both our in vitro and in vivo results suggest an impairment of cell motility and a reduction in micrometastasis formation upon knockdown of NR1D1, accompanied by altered expression levels of SNAI1 and CD44. Interestingly we show that differential proliferation and reduced tumour growth in vivo may be due to the additional influence of the host-clock and/or to the 3D tumour architecture. Our results raise new questions concerning host–tumour interaction and show that core-clock genes are involved in key cancer properties, including the regulation of cell migration and invasion by NR1D1 in zebrafish xenografts.

Central and peripheral clocks in Atlantic bluefin tuna (Thunnus thynnus, L.): Daily rhythmicity of hepatic lipid metabolism and digestive genes

Atlantic bluefin tuna (ABT; Thunnus thynnus) is a highly regarded and consumed species, but farming is still in its infancy. Currently, nothing is known about the presence of circadian rhythmicity at central or peripheral tissues, or if there are daily rhythms in expression of genes involved in lipid metabolism. In order to elucidate clock gene regulation of genes of lipid metabolism in ABT, six clock genes (bmal1, clock, cry1, cry2, per1 and per2) were sequenced and 24 h expression of these genes determined in brain and liver of fish acclimated to a light:dark (L:D) photoperiod. Additionally, the daily expression of lipid metabolism and digestive enzyme genes in ABT was also determined in liver. All six clock genes displayed rhythmicity in the brain and liver, other than cry2, which did not show an acrophase in liver. In liver, all the transcription factors analysed other than srebp1 and srebp2 displayed rhythmicity, with lxr and pparα displaying diurnal expression, whereas pparγ was highly expressed at the end of the scotophase. Some of the target genes of lxr such as elovl5 and lpl also oscillated rhythmically, with acrophases during the photophase. In contrast, only three of the eight digestive enzyme genes studied displayed rhythmicity, at different times of the day, suggesting that either ABT display different feeding periods or the digestion of some nutrients (e.g. lipids) is prioritized over others. The present study showed that clock and lipid metabolism genes displayed strong daily rhythmicity in ABT brain and liver, which could be an area of considerable interest for the establishment of efficient feeding protocols in this new aquaculture species.

Circadian rhythm of expression of core clock genes in the photosensitive pineal organ of catfish, Clarias gariepinus under different photoperiodic regimes

ABSTRACT Effects of different regimes of photoperiod (12L–12D, 16L–8D, 8L–16D, LL and DD) were studied on the circadian rhythm of expression of core clock genes (clock, bmal1, per1, per2, per3, cry1 and cry2) in the photosensitive pineal organ of air-breathing catfish, Clarias gariepinus during summer and winter seasons under both in vivo and in vitro conditions using qPCR. Our findings indicate that all major core clock genes are expressed in the photosensitive pineal organ of C. gariepinus, and exhibit significant circadian rhythm of their expression under both in vivo and in vitro conditions irrespective of photoperiods and seasons. However, photoperiods had season-dependent differential effects on mesor (24 h average), amplitude, and acrophase (peak) of the circadian rhythm of expression of the clock genes under both in vivo and in vitro conditions. Based on these findings, we suggest that the photosensitive pineal organ of the fish possesses internal autonomous clockwork composed of clock genes, and different photoperiods deferentially affect rhythm parameters of the rhythmic expression of the pineal clock genes in a season-dependent manner.

Age-Induced Differential Changes in the Central and Colonic Human Circadian Oscillators.

Aging modifies not only multiple cellular and homeostatic systems, but also biological rhythms. The circadian system is driven by a central hypothalamic oscillator which entrains peripheral oscillators, in both cases underlain by circadian genes. Our aim was to characterize the effect of aging in the circadian expression of clock genes in the human colon. Ambulatory recordings of the circadian rhythms of skin wrist temperature, motor activity and the integrated variable TAP (temperature, activity and position) were dampened by aging, especially beyond 74 years of age. On the contrary, quantitative analysis of genes expression in the muscle layer of colonic explants during 24 h revealed that the circadian expression of Bmal1, Per1 and Clock genes, was larger beyond that age. In vitro experiments showed that aging induced a parallel increase in the myogenic contractility of the circular colonic muscle. This effect was not accompanied by enhancement of Ca2+ signals. In conclusion, we describe here for the first time the presence of a molecular oscillator in the human colon. Aging has a differential effect on the systemic circadian rhythms, that are impaired by aging, and the colonic oscillator, that is strengthened in parallel with the myogenic contractility.

IMMUNE AND GENETIC STATUS OF WOMEN WITH REPRODUCTIVE DISORDERS IN THE CONDTIONS OF EXPOSED CONTAMINATION OF BIOLOGICAL MEDIA WITH PHENOLS

Introduction. A Hormon-like agent such as phenol is able both to integrate into the work of hypothalamus-pituitary-ovary system and trigger a cascade of responses that leads to the development of the immune, hormonal and endocrine systems disorder. Material and methods. The study included 181 woman who permanently live in the area with contamination with phenol in air above standard level. All women are comparable in age, material status and ethnicity. Immunological and hormonal indices were determined by enzyme immunoassay, genetic markers were detected by polymerase chain reaction. Statistical data processing was carried out with the soffware Statistica 10.0, using parametric and non-parametric methods. Results. Between the study groups there were obtained significant differences in following markers: thyroid-stimulating hormone, serotonin, interleukin 6, interleukin 10, estradiol. The dependence of appearance of unfavorable reproductive effects on the presence of polymorphic allele’s was determined: A allele of a gene SULT1A1, G allele of a gene PER2, C allele of a gene SIRT1. Correlation models are defined: thyroid-stimulating hormone and phenol, serotonin and phenol, thyroid-stimulating hormone and cresol, serotonin and cresol, estradiol and cresol. Conclusion. All found markers (increased concentration of phenol in biological media, gene polymorphism, altered protein and receptor expression) create special conditions for the course of the miscarriage pathology.

The impact of social jetlag and chronotype on attention, inhibition and decision making in healthy adults.

Sleep and circadian clock disruption are associated with neuropsychiatric disorders, such as attention deficit hyperactivity disorder, but the impact on neurocognitive performance is unclear. We assessed whether chronotype and everyday circadian misalignment manifested as social jetlag were associated with inter-individual neurocognitive performance across domains of attention, inhibitory control and decision making. One hundred and eighty-eight healthy young adults were assessed for sleep and circadian properties and performed two neurocognitive tasks, the Continuous Performance Test and the Iowa Gambling Task. Social jetlag was associated with significantly faster and less variable reaction times and commission errors on the Continuous Performance Test. Poorer subjective sleep quality was associated with poorer decision making on the Iowa Gambling Task. No effects were present for polymorphisms in the circadian clock genes CLOCK and PER3. We conclude that circadian disruption shaped by everyday environmental factors may impact on attentional/inhibitory performance but not on a measure of risky decision making.

Doxorubicin modulated clock genes and cytokines in macrophages extracted from tumor-bearing mice

ABSTRACT Circadian rhythm is essential for cellular regulation of physiological, metabolic, and immune functions. Perturbations of circadian rhythms have been correlated with increased susceptibility to cancer and poor prognosis in the cancer treatment. Our aim is to investigate the role of doxorubicin (DOX) treatment on clock genes expression and inflammation in intraperitoneal macrophages and the antitumoral response. Methods: Macrophages were extracted from intraperitoneal cavity of mice without or with Lewis lung carcinoma (LLC) and treated with DOX totaling four groups (CTL, LLC, LLC+DOX and DOX) and analyzes of clock genes in six time points (ZT02, ZT06, ZT10, ZT14, ZT18 AND ZT22). Intraperitoneal macrophages cell culture was stimulated with LPS and DOX and clock genes and inflammatory profile were analyzed. In tumor were analyzed macrophages markers. Results: The expression of F4/80 (ZT22) and CD11c (ZT06) tumor tissue was significantly differed between LLC and LCC+DOX groups. In the intraperitoneal macrophages, DOX increased Clock (ZT10), Rev-Erbα (ZT18 and ZT22) and Per2 expressions (ZT18); in the LLC+DOX group was increased Bmal1 (ZT10), Per2 (ZT18) and NF-kB (ZT22) expressions; IL-6 expression increased in the LCC group (ZT02). In intraperitoneal macrophages cell culture stimulated with DOX and LPS after 24 h decreased Clock and Per1. DOX causes depression after 6 and 24 h in TNF-α content and Per2 gene expression after 24 h IL-1β expression was reduced also. Conclusion: DOX treatment in vivo disrupted cytokine and clock genes expression in intraperitoneal macrophages suppressing immune response. Moreover, macrophages cultured with DOX had decreased expression of LPS-stimulated inflammatory cytokines.