The circadian system of mammals regulates the timing of occurrence of behavioral and physiological events, thereby optimizing adaptation to their surroundings. This system is composed of a single master pacemaker located in the suprachiasmatic nucleus (SCN) and a population of peripheral clocks. The SCN integrates time information from exogenous sources and, in turn, synchronizes the downstream peripheral clocks. It is assumed that under normal conditions, the circadian phenotype of different peripheral clocks would be conserved with respect to its period and robustness. To study this idea, we measured the daily wheel-running activity (WRA; a marker of the SCN output) in 84 male inbred LEW/Crl rats housed under a 12 h:12 h light-dark cycle. In addition, we assessed the mRNA expression of two clock genes, rPer2 and rBmal1, and one clock-controlled gene, rDbp, in four tissues that have the access to time cues other than those emanating from the SCN: olfactory bulbs (OBs), liver, tail skin, and white blood cells (WBCs). In contrast with the assumption stated above, we found that circadian clocks in peripheral tissues differ in the temporal pattern of the expression of circadian clock genes, in the robustness of the rhythms, and possibly in the number of functional ~24-h-clock cells. Based on the tissue diversity in the robustness of the clock output, the hepatic clock is likely to house the highest number of functional ~24-h-clock cells, and the OBs, the fewest number. Thus, the phenotype of the circadian clock in the periphery is tissue specific and may depend not only on the SCN but also on the sensitivity of the tissue to non-SCN-derived time cues. In the OBs and liver, the circadian clock phenotypes seem to be dominantly shaped by the SCN output. However, in the tail skin and WBC, other time cues participate in the phenotype design. Finally, our study suggests that the basic phenotype of the circadian clock is constructed at the transcript level of the core clock genes. Yet, additional posttranscriptional and translational events can contribute to the robustness and periodicity of the clock output.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.3109/07420528.2012.754451 | DOI Listing |
Life (Basel)
January 2025
Sleep Medicine Institute, Jungwon University, Goesan-gun 28204, Chungcheongbuk-do, Republic of Korea.
Sleep disruption has emerged as a significant public health concern with profound implications for metabolic health. This review synthesizes current evidence demonstrating the intricate relationships between sleep disturbances and cardiometabolic dysfunction. Epidemiological studies have consistently demonstrated that insufficient sleep duration (<7 h) and poor sleep quality are associated with increased risks of obesity, type 2 diabetes, and cardiovascular disease.
View Article and Find Full Text PDFInt J Mol Sci
January 2025
Division of Pharmaceutics, Faculty of Pharmaceutical Sciences, Sanyo-Onoda City University, Yamaguchi 756-0884, Japan.
The application of regenerative therapy through stem cell transplantation has emerged as a promising avenue for the treatment of diabetes mellitus (DM). Transplanted tissue homeostasis is affected by disturbances in the clock genes of stem cells. The aim of this study is to investigate the diurnal variation in mitochondrial genes and function after transplantation of adipose-derived mesenchymal stem cells (T2DM-ADSCs) from type 2 diabetic patients into immunodeficient mice.
View Article and Find Full Text PDFBiomolecules
January 2025
Department of Urology, Renmin Hospital of Wuhan University, Wuhan 430060, China.
Acute kidney injury (AKI) and chronic kidney disease (CKD) represent two frequently observed clinical conditions. AKI is characterized by an abrupt decrease in glomerular filtration rate (GFR), generally associated with elevated serum creatinine (sCr), blood urea nitrogen (BUN), and electrolyte imbalances. This condition usually persists for approximately a week, causing a transient reduction in kidney function.
View Article and Find Full Text PDFVet Sci
January 2025
College of Animal Science and Technology, Northwest A&F University, Yangling 712100, China.
Organisms have the capacity to detect day-night fluctuations through oscillators regulated by circadian clock genes, which are crucial for regulating various biological processes. Numerous studies have demonstrated a marked association between these genes and various growth traits of sheep. This study identified polymorphisms at 23 potential loci within five clock genes in four Chinese sheep breeds.
View Article and Find Full Text PDFCells
January 2025
Department of Otolaryngology, Tokyo Teishin Hospital, Tokyo 102-0071, Japan.
Background/objectives: This study evaluated changes in circadian clock genes and mitochondrial function in a lead (Pb)-induced toxicity model of an olfactory epithelial cell line.
Methods: The DBC1.2 olfactory dark basal cell line was used.
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!