Modeling Transient Changes in Circadian Rhythms II
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PROVIDER: PRJNA1006025 | ENA |
REPOSITORIES: ENA
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Project description:Modeling Transient Changes in Circadian Rhythms I
| PRJNA1006022 | ENA
Project description:The circadian clock can adapt itself to external cues, but the molecular mechanisms and regulatory networks governing circadian oscillations' transient adjustments are still largely unknown. Here we consider the specific case of circadian oscillations transiently responding to a temperature change. Using a framework motivated by Floquet theory, we model the mRNA expression level of the fat body from Drosophila melanogaster following a step change from 25C to 18C. Using the method we infer the adaptation rates of individual genes as they adapt to the new temperature. To deal with heteroskedastic noise and outliers present in the expression data we employ quantile regression and wild bootstrap for significance testing. Model selection with finite-sample corrected Akaike Information Criterion (AICc) is performed additionally for robust inference. We identify several genes with fast transition rates as potential sources of temperature-mediated responses in the circadian system of fruit flies, and the constructed network suggests that the proteasome may play important roles in governing these responses.
2023-12-05 | GSE241003 | GEO
Project description:The circadian clock can adapt itself to external cues, but the molecular mechanisms and regulatory networks governing circadian oscillations' transient adjustments are still largely unknown. Here we consider the specific case of circadian oscillations transiently responding to a temperature change. Using a framework motivated by Floquet theory, we model the mRNA expression level of the fat body from Drosophila melanogaster following a step change from 25C to 18C. Using the method we infer the adaptation rates of individual genes as they adapt to the new temperature. To deal with heteroskedastic noise and outliers present in the expression data we employ quantile regression and wild bootstrap for significance testing. Model selection with finite-sample corrected Akaike Information Criterion (AICc) is performed additionally for robust inference. We identify several genes with fast transition rates as potential sources of temperature-mediated responses in the circadian system of fruit flies, and the constructed network suggests that the proteasome may play important roles in governing these responses.
2023-12-05 | GSE241002 | GEO
Project description:Observational, non randomized study aimed at measuring the circadian rhythms in the urinary concentrations of physiological modified nucleosides in 30 patients with metastatic colorectal cancer and in 30 age and sex-matched healthy subjects.
| 2132582 | ecrin-mdr-crc
Project description:Dietary tryptophan and circadian rhythms
| PRJNA773065 | ENA
Project description:Circadian rhythms in plant roots
| PRJEB5695 | ENA
Project description:Recent evidence suggest that the circadian timing system plays an important role in the control of renal function and maintaining blood pressure. Here, we analyzed circadian rhythms of urinary excretion of sodium and potassium in wild-type mice and mice lacking circadian transcriptional activator clock. Analysis of urines collected at hourly intervals over a 24-hour period revealed dramatic changes in rhythms of sodium and potassium excretion in clock(-/-) mice. In parallel, significant differences in circadian pattern of plasma aldosterone levels, but not in the 24-hour mean aldosterone levels, were observed. Microarray-based profiling of renal transcriptomes demonstrated that clock(-/-) mice exhibit dysregulation in multiple mechanisms involved in maintaining sodium and potassium balance by the kidney. The most significant changes were detected in the expression levels of several key enzymes (Cyp4a14, Cyp4a12a and Cyp4a12b) required for the conversion of arachidonic acid to 20-hydroxyeicosatetraenoic acid (20-HETE), a powerful regulator of renal sodium and potassium excretion, renal vascular tone and blood pressure. The 20-HETE levels measured in kidney microsomes of wild-type mice followed a circadian-like temporal pattern. In clock(-/-) mice, the acrophase of this rhythm was shifted by 8 hours and the 24-hour mean levels of 20-HETE were significantly decreased. These results demonstrate that circadian rhythms of urine electrolyte excretion are largely dependent on the circadian clock activity and indicate that circadian oscillations in renal 20-HETE content could be an important mechanism of blood pressure regulation. We examined the temporal profiles of gene expression in mouse whole kidney. Animals were sacrificed for microdissection every 4 hours, i.e. at ZT0, ZT4, ZT8, ZT12, ZT16 and ZT20 (ZT M-bM-^@M-^S Zeitgeber (circadian) time, indicates time of light-on as ZT0 and time of light-off as ZT12). The microarray hybridization was performed in duplicates on pools of RNA composed of equivalent amounts of RNA prepared from teo or three animals at each ZT time-point.
2012-04-29 | E-GEOD-27366 | biostudies-arrayexpress
Project description:Disrupted circadian rhythms in a mouse model of schizophrenia
2012-03-01 | E-MEXP-3493 | biostudies-arrayexpress
Project description:Recent evidence suggest that the circadian timing system plays an important role in the control of renal function and maintaining blood pressure. Here, we analyzed circadian rhythms of urinary excretion of sodium and potassium in wild-type mice and mice lacking circadian transcriptional activator clock. Analysis of urines collected at hourly intervals over a 24-hour period revealed dramatic changes in rhythms of sodium and potassium excretion in clock(-/-) mice. In parallel, significant differences in circadian pattern of plasma aldosterone levels, but not in the 24-hour mean aldosterone levels, were observed. Microarray-based profiling of renal transcriptomes demonstrated that clock(-/-) mice exhibit dysregulation in multiple mechanisms involved in maintaining sodium and potassium balance by the kidney. The most significant changes were detected in the expression levels of several key enzymes (Cyp4a14, Cyp4a12a and Cyp4a12b) required for the conversion of arachidonic acid to 20-hydroxyeicosatetraenoic acid (20-HETE), a powerful regulator of renal sodium and potassium excretion, renal vascular tone and blood pressure. The 20-HETE levels measured in kidney microsomes of wild-type mice followed a circadian-like temporal pattern. In clock(-/-) mice, the acrophase of this rhythm was shifted by 8 hours and the 24-hour mean levels of 20-HETE were significantly decreased. These results demonstrate that circadian rhythms of urine electrolyte excretion are largely dependent on the circadian clock activity and indicate that circadian oscillations in renal 20-HETE content could be an important mechanism of blood pressure regulation.
2012-04-30 | GSE27366 | GEO
Project description:Circadian rhythms are responsive to a variety of external cues, light and metabolism being the most important. In mammals, the light signal is sensed by the retina and transmitted to the SCN master clock, where it is translated into the molecular oscillator via regulation of clock gene transcription. The signalling pathways governing the molecular translation from metabolic signals to circadian output in peripheral oscillators, in contrast, are less understood. FOXO transcription factors are known to translate external metabolic cues to internal transcriptional programs. In the past couple of years it has become evident that both FOXO transcription factors and the circadian clock are of key importance in the underlying mechanisms of ageing and the regulation of metabolism. We now show FOXO3 to be a crucial modulator of circadian rhythmicity via direct transcriptional regulation of Clock, a core component of the molecular oscillator, and identify FOXO3 as a novel link in the circadian feedback loop, which is required for circadian rhythms in liver. We propose that FOXO3 directly feeds back into the circadian oscillator in response to metabolic cues. We performed a microarray study on synchronized NIH 3T3 cells upon transient overexpression of FoxO6 (oeO6). Cells were harvested for RNA isolation 24h (time1), 30h(time2), 36h(time3) and 42h(time4) after synchronization. Experimental samples were hybridized against a reference pool of cRNA, which was derived from unsynchronized NIH 3T3 cells. Experiments were performed 4 times, of each sample group two samples were labeled with cy5 and co-hybridized with reference RNA labeled with cy3, and two samples were labeled and hybridized in the opposite way. Microarrays used were Mouse Whole Genome Gene Expression Microarrays V1 (Agilent Technologies, Belgium)
2014-06-03 | E-GEOD-41554 | biostudies-arrayexpress