Restricted feeding schedules (RFS) entrain digestive, hormonal, and metabolic functions as well as oscillations of clock genes, such as Per1 and Per2, in peripheral organs. In the brain, in particular the hypothalamus, RFS induce and shift daily rhythms of Per1 and Per2 expression. To determine whether RFS affect clock genes in extra-SCN oscillators in a uniform manner, the present study investigated daily rhythms of Per1, Per2, and Bmal1 expression in various hypothalamic regions. Wistar rats were entrained to daily RFS (2 h food access starting at ZT6, RFS) or fed ad libitum (C) for three weeks. Brains were sampled every 3 h starting at ZT0, and were processed with in situ hybridization. In response to RFS, Per1 expression showed a 3 h phase advance in the suprachiasmatic nucleus (SCN), while Per2 and Bmal1 remained unaffected. Per1 was triggered at ZT6, anticipating food access in both arcuate (ARC) and dorsomedial nuclei (DMH), and was unaffected in the ventromedial (VMH) and paraventricular (PVN) nuclei. In contrast, Per2 expression during RFS showed a marked postprandial peak in the PVN, was unchanged in the ARC, and was down-regulated in the DMH and VMH. The temporal patterns of Bmal1 expression were not significantly modified in RFS rats. RFS differentially affected clock-gene expression (phase change, up- or downregulation) depending on the combination of hypothalamic nuclei and targeted genes. Present data highlight that metabolic or temporal cues elicited by feeding modify the temporal organization in the hypothalamus and are not exclusive for a food-entrained oscillator.
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http://dx.doi.org/10.1080/07420520903044240 | DOI Listing |
Pigment Cell Melanoma Res
January 2025
Department of Cell Biology and Anatomy, Alberta Children's Hospital Research Institute, University of Calgary, Calgary, Alberta, Canada.
Circadian regulation of skin pigmentation is essential for thermoregulation, ultraviolet (UV) protection, and synchronization of skin cell renewal. This regulation involves both cell-autonomous photic responses and non-cell-autonomous hormonal control, particularly through melatonin produced in a light-sensitive manner. Photosensitive opsins, cryptochromes, and melatonin regulate circadian rhythms in skin pigment cells.
View Article and Find Full Text PDFCell Commun Signal
January 2025
College of Life Science, Yangtze University, Jingzhou, 434025, China.
The complex interaction between circadian rhythms and physiological functions is essential for maintaining human health. At the heart of this interaction lies the PERIOD proteins (PERs), pivotal to the circadian clock, influencing the timing of physiological and behavioral processes and impacting oxidative stress, immune functionality, and tumorigenesis. PER1 orchestrates the cooperation of the enzyme GPX1, modulating mitochondrial dynamics in sync with daily rhythms and oxidative stress, thus regulating the mechanisms managing energy substrates.
View Article and Find Full Text PDFBiophys J
January 2025
Department of Chemistry and Biochemistry, Worcester Polytechnic Institute, Worcester, Massachusetts. Electronic address:
Cells respond to hypoosmotic stress by initial swelling followed by intracellular increases in the number of osmolytes and initiation of gene transcription that allow cells to adapt to the stress. Here, we have studied the genes that change expression under mild hypoosmotic stress for 12 and 24 h in rat cultured smooth muscle cells (WKO-3M22). We find shifts in the transcription of many genes, several of which are associated with circadian rhythm, such as per1, nr1d1, per2, dbp, and Ciart.
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January 2025
National Key Laboratory of Veterinary Public Health Security, College of Veterinary Medicine, China Agricultural University, Haidian, Beijing 100193, China. Electronic address:
Obesity is a contributing factor that increases the likelihood of developing chronic kidney disease. In recent years, studies have found that light pollution worldwide promoted obesity, which was known to be a consequence of circadian rhythm disruption. Nevertheless, the impact of light pollution on kidney disease associated with obesity remains mostly unknown, and potential processes have been minimally investigated.
View Article and Find Full Text PDFJ Anim Sci
January 2024
Department of Animal and Dairy Sciences, Mississippi State University, Starkville, MS 39762, USA.
The neuroendocrine hormone melatonin is associated with circadian rhythms and has antioxidant and vasodilative properties. In cattle, melatonin rescues fetal growth during maternal nutrient restriction in a seasonally dependent manner, but melatonin research in swine is limited. The objective of this study was to evaluate the effects of dietary melatonin supplementation during mid to late gestation on circadian rhythm and muscle growth and development of the longissimus dorsi in utero and postnatally.
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