Browsing by Subject "CIRCADIAN-RHYTHMS"

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  • Rozov, Stanislav V.; Zant, Janneke; Gurevicius, Kestutis; Porkka-Heiskanen, Tarja; Panula, Pertti (2016)
    Aim: Under natural conditions diurnal rhythms of biological processes of the organism are synchronized with each other and to the environmental changes by means of the circadian system. Disturbances of the latter affect hormonal levels, sleep-wakefulness cycle and cognitive performance. To study mechanisms of such perturbations animal models subjected to artificial photoperiods are often used. The goal of current study was to understand the effects of circadian rhythm disruption, caused by a short light-dark cycle regime, on activity of the cerebral cortex in rodents. Methods: We used electroencephalogram to assess the distribution of vigilance states, perform spectral analysis, and estimate the homeostatic sleep drive. In addition, we analyzed spontaneous locomotion of C57BL/6J mice under symmetric, 22-, 21-, and 20-h-long light-dark cycles using video recording and tracking methods. Results and Conclusions: We found that shortening of photoperiod caused a significant increase of slow wave activity during non-rapid eye movement sleep suggesting an elevation of sleep pressure under such conditions. While the rhythm of spontaneous locomotion was completely entrained by all light-dark cycles tested, periodic changes in the power of the theta- and gamma-frequency ranges during wakefulness gradually disappeared under 22- and 21-h-long light-dark cycles. This was associated with a significant increase in the theta-gamma phase-amplitude coupling during wakefulness. Our results thus provide deeper understanding of the mechanisms underlying the impairment of learning and memory retention, which is associated with disturbed circadian regulation.
  • Bauer, Michael; Glenn, Tasha; Alda, Martin; Andreassen, Ole A.; Angelopoulos, Elias; Ardau, Raffaella; Ayhan, Yavuz; Baethge, Christopher; Bauer, Rita; Baune, Bernhard T.; Becerra-Palars, Claudia; Bellivier, Frank; Belmaker, Robert H.; Berk, Michael; Bersudsky, Yuly; Bicakci, Sule; Birabwa-Oketcho, Harriet; Bjella, Thomas D.; Cabrera, Jorge; Cheung, Eric Y. Wo; Del Zompo, Maria; Dodd, Seetal; Donix, Markus; Etain, Bruno; Fagiolini, Andrea; Fountoulakis, Kostas N.; Frye, Mark A.; Gonzalez-Pinto, Ana; Gottlieb, John F.; Grof, Paul; Harima, Hirohiko; Henry, Chantal; Isometsä, Erkki T.; Janno, Sven; Kapczinski, Flavio; Kardell, Mathias; Khaldi, Slim; Kliwicki, Sebastian; Konig, Barbara; Kot, Timur L.; Krogh, Rikke; Kunz, Mauricio; Lafer, Beny; Landen, Mikael; Larsen, Erik R.; Lewitzka, Ute; Licht, Rasmus W.; Lopez-Jaramillo, Carlos; MacQueen, Glenda; Manchia, Mirko; Marsh, Wendy; Martinez-Cengotitabengoa, Monica; Melle, Ingrid; Meza-Urzua, Fatima; Ming, Mok Yee; Monteith, Scott; Morken, Gunnar; Mosca, Enrica; Mozzhegorova, Anton A.; Munoz, Rodrigo; Mythri, Starlin V.; Nacef, Fethi; Nadella, Ravi K.; Nery, Fabiano G.; Nielsen, Rene E.; O'Donovan, Claire; Omrani, Adel; Osher, Yamima; Sorensen, Helle Ostermark; Ouali, Uta; Ruiz, Yolanda Pica; Pilhatsch, Maximilian; Pinna, Marco; da Ponte, Francisco D. R.; Quiroz, Danilo; Ramesar, Raj; Rasgon, Natalie; Reddy, M. S.; Reif, Andreas; Ritter, Philipp; Rybakowski, Janusz K.; Sagduyu, Kemal; Raghuraman, Bharathram Sathur; Scippa, Angela M.; Severus, Emanuel; Simhandl, Christian; Stackhouse, Paul W.; Stein, Dan J.; Strejilevich, Sergio; Subramaniam, Mythily; Sulaiman, Ahmad Hatim; Suominen, Kirsi; Tagata, Hiromi; Tatebayashi, Yoshitaka; Tondo, Leonardo; Torrent, Carla; Vaaler, Arne E.; Vares, Edgar; Veeh, Julia; Vieta, Eduard; Viswanath, Biju; Yoldi-Negrete, Maria; Zetina, Mark; Zgueb, Yosra; Whybrow, Peter C. (2019)
    In many international studies, rates of completed suicide and suicide attempts have a seasonal pattern that peaks in spring or summer. This exploratory study investigated the association between solar insolation and a history of suicide attempt in patients with bipolar I disorder. Solar insolation is the amount of electromagnetic energy from the Sun striking a surface area on Earth. Data were collected previously from 5536 patients with bipolar I disorder at 50 collection sites in 32 countries at a wide range of latitudes in both hemispheres. Suicide related data were available for 3365 patients from 310 onset locations in 51 countries. 1047 (31.1%) had a history of suicide attempt. There was a significant inverse association between a history of suicide attempt and the ratio of mean winter solar insolation/mean summer solar insolation. This ratio is smallest near the poles where the winter insolation is very small compared to the summer insolation. This ratio is largest near the equator where there is relatively little variation in the insolation over the year. Other variables in the model that were positively associated with suicide attempt were being female, a history of alcohol or substance abuse, and being in a younger birth cohort. Living in a country with a state-sponsored religion decreased the association. (All estimated coefficients p <0.01). In summary, living in locations with large changes in solar insolation between winter and summer may be associated with increased suicide attempts in patients with bipolar disorder. Further investigation of the impacts of solar insolation on the course of bipolar disorder is needed.
  • Sulkava, Sonja; Ollila, Hanna M.; Alasaari, Jukka; Puttonen, Sampsa; Harma, Mikko; Viitasalo, Katriina; Lahtinen, Alexandra; Lindstrom, Jaana; Toivola, Auli; Sulkava, Raimo; Kivimaki, Mika; Vahtera, Jussi; Partonen, Timo; Silander, Kaisa; Porkka-Heiskanen, Tarja; Paunio, Tiina (2017)
    Study Objectives: Tolerance to shift work varies; only some shift workers suffer from disturbed sleep, fatigue, and job-related exhaustion. Our aim was to explore molecular genetic risk factors for intolerance to shift work. Methods: We assessed intolerance to shift work with job-related exhaustion symptoms in shift workers using the emotional exhaustion subscale of the Maslach Burnout Inventory-General Survey, and carried out a genome-wide association study (GWAS) using Illumina's Human610-Quad BeadChip (n = 176). The most significant findings were further studied in three groups of Finnish shift workers (n = 577). We assessed methylation in blood cells with the Illumina HumanMethylation450K BeadChip, and examined gene expression levels in the publicly available eGWAS Mayo data. Results: The second strongest signal identified in the GWAS (p = 2.3 x 10E-6) was replicated in two of the replication studies with p Conclusions: These findings suggest that a variant near MTNR1A may be associated with job-related exhaustion in shift workers. The risk variant may exert its effect via epigenetic mechanisms, potentially leading to reduced melatonin signaling in the brain. These results could indicate a link between melatonin signaling, a key circadian regulatory mechanism, and tolerance to shift work.
  • Olkkonen, Juri; Kouri, Vesa-Petteri; Hynninen, Joel; Konttinen, Yrjo T.; Mandelin, Jami (2015)
    Objective Patients with rheumatoid arthritis (RA) have altered circadian rhythm of circulating serum cortisol, melatonin and IL-6, as well as disturbance in the expression of clock genes ARNTL2 and NPAS2. In humans, TNF alpha increases the expression ARNTL2 and NPAS2 but paradoxically suppresses clock output genes DPB and PER3. Our objective was to investigate the expression of direct clock suppressors DEC1 and DEC2 (BHLHE 40 and 41 proteins) in response to TNF alpha and investigate their role during inflammation. Methods Cultured primary fibroblasts were stimulated with TNF alpha. Effects on DEC2 were studied using RT-qPCR and immunofluorescence staining. The role of NF-kappa B in DEC2 increase was analyzed using IKK-2 specific inhibitor IMD-0354. Cloned DEC2 was transfected into HEK293 cells to study its effects on gene expression. Transfections into primary human fibroblasts were used to confirm the results. The presence of DEC2 was analyzed in (RA) and osteoarthritis (OA) synovial membranes by immunohistochemistry. Results TNF alpha increased DEC2 mRNA and DEC2 was mainly detected at nuclei after the stimulus. The effects of TNF alpha on DEC2 expression were mediated via NF-kappa B. Overexpression, siRNA and promoter activity studies disclosed that DEC2 directly regulates IL-1 beta, in both HEK293 cells and primary human fibroblasts. DEC2 was increased in synovial membrane in RA compared to OA. Conclusion Not only ARNTL2 and NPAS2 but also DEC2 is regulated by TNF alpha in human fibroblasts. NF-kappa B mediates the effect on DEC2, which upregulates IL-1 beta. Circadian clock has a direct effect on inflammation in human fibroblasts.
  • Basnet, Syaron; Merikanto, Ilona; Lahti, Tuuli; Männistö, Satu; Laatikainen, Tiina; Vartiainen, Erkki; Partonen, Timo (2018)
    Introduction: The seasonal pattern for mood and behaviour, the behavioural trait of morningness-eveningness, and sleep are interconnected features, that may serve as etiological factors in the development or exacerbation of medical conditions. Methods: The study was based on a random sample of inhabitants aged 25 to 74 years living in Finland. As part of the national FINRISK 2012 study participants were invited (n=9905) and asked whether the doctor had diagnosed or treated them during the past 12 months for chronic diseases. Results: A total of 6424 participants filled in the first set of questionnaires and 5826 attended the physical health status examination, after which the second set of questionnaires were filled. Regression models were built in which each condition was explained by the seasonal, diurnal and sleep features, after controlling for a range of background factors. Of the chronic diseases, depressive disorder was associated with longer total sleep duration (p
  • Bauer, Michael; Glenn, Tasha; Achtyes, Eric D.; Alda, Martin; Agaoglu, Esen; Altinbas, Kursat; Andreassen, Ole A.; Angelopoulos, Elias; Ardau, Raffaella; Vares, Edgar Arrua; Aydin, Memduha; Ayhan, Yavuz; Baethge, Christopher; Bauer, Rita; Baune, Bernhard T.; Balaban, Ceylan; Becerra-Palars, Claudia; Behere, Aniruddh P.; Behere, Prakash B.; Belete, Habte; Belete, Tilahun; Belizario, Gabriel Okawa; Bellivier, Frank; Belmaker, Robert H.; Benedetti, Francesco; Berk, Michael; Bersudsky, Yuly; Bicakci, Sule; Birabwa-Oketcho, Harriet; Bjella, Thomas D.; Brady, Conan; Cabrera, Jorge; Cappucciati, Marco; Castro, Angela Marianne Paredes; Chen, Wei-Ling; Cheung, Eric Y. Wo; Chiesa, Silvia; Crowe, Marie; Cuomo, Alessandro; Dallaspezia, Sara; Del Zompo, Maria; Desai, Pratikkumar; Dodd, Seetal; Donix, Markus; Etain, Bruno; Fagiolini, Andrea; Fellendorf, Frederike T.; Ferensztajn-Rochowiak, Ewa; Fiedorowicz, Jess G.; Isometsa, Erkki T. (2021)
    Background Bipolar disorder is associated with circadian disruption and a high risk of suicidal behavior. In a previous exploratory study of patients with bipolar I disorder, we found that a history of suicide attempts was associated with differences between winter and summer levels of solar insolation. The purpose of this study was to confirm this finding using international data from 42% more collection sites and 25% more countries. Methods Data analyzed were from 71 prior and new collection sites in 40 countries at a wide range of latitudes. The analysis included 4876 patients with bipolar I disorder, 45% more data than previously analyzed. Of the patients, 1496 (30.7%) had a history of suicide attempt. Solar insolation data, the amount of the sun's electromagnetic energy striking the surface of the earth, was obtained for each onset location (479 locations in 64 countries). Results This analysis confirmed the results of the exploratory study with the same best model and slightly better statistical significance. There was a significant inverse association between a history of suicide attempts and the ratio of mean winter insolation to mean summer insolation (mean winter insolation/mean summer insolation). This ratio is largest near the equator which has little change in solar insolation over the year, and smallest near the poles where the winter insolation is very small compared to the summer insolation. Other variables in the model associated with an increased risk of suicide attempts were a history of alcohol or substance abuse, female gender, and younger birth cohort. The winter/summer insolation ratio was also replaced with the ratio of minimum mean monthly insolation to the maximum mean monthly insolation to accommodate insolation patterns in the tropics, and nearly identical results were found. All estimated coefficients were significant at p < 0.01. Conclusion A large change in solar insolation, both between winter and summer and between the minimum and maximum monthly values, may increase the risk of suicide attempts in bipolar I disorder. With frequent circadian rhythm dysfunction and suicidal behavior in bipolar disorder, greater understanding of the optimal roles of daylight and electric lighting in circadian entrainment is needed.
  • Fernández-Marín, Beatriz; Atherton, Jon; Olascoaga, Beñat; Kolari, Pasi; Porcar Castell, Albert; García-Plazaola, José I. (2018)
    Subarctic plants in summer (subjected to continuous light) showed photosynthetic pigment contents mainly driven by PPFD (unrelated to day/night cycles) and a xanthophyll cycle responsiveness to PPFD exacerbated during night-times. Composition and content of photosynthetic pigments is finely tuned by plants according to a subtle equilibrium between the absorbed and used energy by the photosynthetic apparatus. Subarctic and Arctic plants are subjected to extended periods of continuous light during summer. This condition represents a unique natural scenario to study the influence of light on pigment regulation and the presence of diurnal patterns potentially governed by circadian rhythms. Here, we examined the modulation of the photosynthetic apparatus in three naturally co-occurring woody species: mountain birch (Betula pubescens ssp. czerepanovii), alpine bearberry (Arctostaphylos alpina) and Scots pine (Pinus sylvestris) around the summer solstice, at 67 A degrees N latitude. Plants were continuously exposed to solar radiation during the 3-day study period, although PPFD fluctuated, being lower during night-times. Photochemical efficiencies for a given PPFD were similar during daytime and night-time for the three species. In Scots pine, for a given PPFD, net assimilation was slightly higher during daytime than during night-time. Overall, the dynamism in pigment content was mainly driven by PPFD, and was generally unrelated to day/night cycles. Weak indications of potential circadian regulation were found over a few pigments only. Interestingly, the xanthophyll cycle was active at any time of the day in the three species but its responsiveness to PPFD was exacerbated during night-times. This was particularly evident for bearberry, which maintained a highly de-epoxidised state even at night-times. The results could indicate an incomplete acclimation to a 24-h photoperiod for these species, which have colonised subarctic latitudes only recently.