An Exploratory Randomized Controlled Study to Investigate Concentration-Dependence of Green Tea Catechin Gargling on Acute Upper Respiratory Tract Infections.

Green tea (GT) catechins exhibit antiviral effects in experimental studies. However, we lack clinical evidence on the preventive effects of catechin concentrations in gargling against acute upper respiratory tract infections (URTIs). Therefore, we aimed to investigate the concentration-dependence of GT catechins in gargling on the incidence of URTIs.

In vivo recording of suprachiasmatic nucleus dynamics reveals a dominant role of arginine vasopressin neurons in circadian pacesetting.

The central circadian clock of the suprachiasmatic nucleus (SCN) is a network consisting of various types of neurons and glial cells. Individual cells have the autonomous molecular machinery of a cellular clock, but their intrinsic periods vary considerably. Here, we show that arginine vasopressin (AVP) neurons set the ensemble period of the SCN network in vivo to control the circadian behavior rhythm.

Circadian rhythm of PERIOD2::LUCIFERASE expression in the trigeminal ganglion of mice.

Introduction: The trigeminal nerve conveys delicate sensations such as warmth, pain, and tactile pressure in the oral and facial regions, and most trigeminal afferent cell bodies are located in the trigeminal ganglion. Our previous study has shown that sensations in trigeminal nerve innervated areas, specifically in the maxillofacial region, exhibit diurnal variation and that sensitivity changes time-dependently. In this study, we aimed to clarify the rhythm of expression of clock gene in the trigeminal ganglion of mice to elucidate the mechanism of circadian regulation in the same area.

Diurnal variations of triglyceride accumulation in mouse and bovine adipocyte-derived cell lines.

Several studies have suggested a strong interaction between the circadian clock and lipid metabolism in mammals. The circadian clock is driven by endogenous cyclic gene expression patterns, commonly referred to as clock genes, and transcription-translation negative feedback loops. Clock genes regulate the transcription of some lipid metabolism-related genes; however, the relationship between the circadian clock and triglyceride (TG) accumulation at the cellular level remains unclear.

Secretin receptor-deficient mice exhibit robust food anticipatory activity.

In mammals, the suprachiasmatic nucleus (SCN) is a principal circadian pacemaker that optimizes the timing of behavioral rhythms and physiological events. Normally, circadian behavioral rhythms are entrained by the environmental light-dark (LD) cycle via the SCN. However, daily rhythms of other synchronizing signals, such as food availability, also emerge.

Oak extracts modulate circadian rhythms of clock gene expression in vitro and wheel-running activity in mice.

Introduction: In mammals, the central circadian clock is located in the suprachiasmatic nucleus (SCN) of the hypothalamus, which coordinates the circadian rhythm and controls locomotor activity rhythms. In addition to SCN cells, the peripheral tissues and embryonic fibroblasts also have clock genes, such as and , which generate the transcriptional-translational feedback loop to produce an approximately 24-h cycle. Aging adversely affects the circadian clock system and locomotor functions.

Role of heterozygous and homozygous alleles in cryptochrome-deficient mice.

The circadian rhythms of physiology and behavior are based on molecular systems at the cellular level, which are regulated by clock genes, including cryptochrome genes, Cry1 and Cry2. In mammals, the circadian pacemaker in the suprachiasmatic nucleus (SCN) of the hypothalamus maintains the circadian rhythms throughout the body. Cry1 and Cry2 play distinct roles in regulating the circadian rhythm.

Diurnal Variation in Trigeminal Pain Sensitivity in Mice.

Management of time and circadian disruption is an extremely important factor in basic research on pain and analgesia. Although pain is known to vary throughout the day, the mechanism underlying this circadian variation remains largely unknown. In this study, we hypothesized that the process of pain transmission to the central nervous system (after receiving nociceptive stimuli from outside the body) would show day-night differences.

Circadian clock regulates tear secretion in the lacrimal gland.

Although diurnal variations have been observed in tear film parameters in various species, the molecular mechanisms that control circadian tear secretion remain unclear. The aim of our study was to evaluate the role of clock genes in the lacrimal gland (LG) in regulation of tear secretion. Tear volume was measured by cotton thread test in core clock genes deficient (Cry1Cry2) mice which are behaviorally arrhythmic.

GABA from vasopressin neurons regulates the time at which suprachiasmatic nucleus molecular clocks enable circadian behavior.

The suprachiasmatic nucleus (SCN), the central circadian pacemaker in mammals, is a network structure composed of multiple types of γ-aminobutyric acid (GABA)-ergic neurons and glial cells. However, the roles of GABA-mediated signaling in the SCN network remain controversial. Here, we report noticeable impairment of the circadian rhythm in mice with a specific deletion of the vesicular GABA transporter in arginine vasopressin (AVP)-producing neurons.

Electrophysiological Approaches to Studying the Suprachiasmatic Nucleus.

In mammals, the part of the nervous system responsible for most circadian behavior can be localized to a bilaterally paired structure in the hypothalamus known as the suprachiasmatic nucleus (SCN). Understanding the mammalian circadian system will require a detailed multilevel analysis of neural SCN circuits ex vivo and in vivo. Many of the techniques and approaches that are used for the analysis of the circuitry driving circadian oscillations in the SCN are similar to those employed in other brain regions.

Modeling circadian regulation of ovulation timing: age-related disruption of estrous cyclicity.

The circadian clocks within the hypothalamic-pituitary-gonadal axis control estrous cycles in female rodents. The suprachiasmatic nucleus (SCN), where the central clock is located, generates daily signals to trigger surge release of luteinizing hormone (LH), which in turn induces ovulation. It has been observed in aged rodents that output from the SCN such as neuronal firing activity is declined, and estrous cycles become irregular and finally stop.

Reciprocal Expression Patterns of Placental Leucine Aminopeptidase/Insulin-Regulated Aminopeptidase and Vasopressin in the Murine Brain.

Placental leucine aminopeptidase/insulin-regulated aminopeptidase (P-LAP/IRAP) regulates vasopressin and oxytocin levels in the brain and peripheral tissues by controlled degradation of these peptides. In this study, we determined the relationship between P-LAP/IRAP and vasopressin levels in subregions of the murine brain. P-LAP/IRAP expression was observed in almost all brain regions.

A high-salt/high fat diet alters circadian locomotor activity and glucocorticoid synthesis in mice.

Salt is an essential nutrient; however, excessive salt intake is a prominent public health concern worldwide. Various physiological functions are associated with circadian rhythms, and disruption of circadian rhythms is a prominent risk factor for cardiovascular diseases, cancer, and immune disease. Certain nutrients are vital regulators of peripheral circadian clocks.

Secretin receptor-deficient mice exhibit altered circadian rhythm in wheel-running activity.

In mammals, the timing of behavior and physiological activity is controlled by the suprachiasmatic nucleus (SCN) in the hypothalamus. Incidentally, secretin is a peptide hormone that promotes digestive activities and regulates water reabsorption. In recent studies, exogenous administration of secretin has been reported to induce secretion of oxytocin in the supraoptic nucleus of the hypothalamus and modulate social behavior.

Suppression of Blue Light at Night Ameliorates Metabolic Abnormalities by Controlling Circadian Rhythms.

Purpose: Light-emitting diodes that emit high-intensity blue light are associated with blue-light hazard. Here, we report that blue light disturbs circadian rhythms by interfering with the clock gene in the suprachiasmatic nucleus (SCN) and that suppression of blue light at night ameliorates metabolic abnormalities by controlling circadian rhythms.

Methods: C57BL/6J mice were exposed to 10-lux light for 30 minutes at Zeitgeber time 14 for light pulse with blue light or blue-light cut light to induce phase shift of circadian rhythms.

Effects of testosterone on circadian rhythmicity in old mice.

Serum testosterone concentration decreases with age in humans and rodents. Accordingly, old male mice show changes in locomotor activity rhythms: a lengthened free-running period and decreased activity levels among others. To investigate whether testosterone replacement improves the age-related decline in circadian rhythmicity, we examined the effects of testosterone on the circadian rhythms of wheel running activity in old male mice.

Acute-phase protein-like properties of endoplasmic reticulum aminopeptidase 1.

Endoplasmic reticulum aminopeptidase 1 (ERAP1) is a multi-functional enzyme. In this study, we analysed its role in lipopolysaccharide-induced inflammatory response in wild-type and ERAP1-knockout mice. Following lipopolysaccharide injection, ERAP1 was secreted into the blood, increasing leucine aminopeptidase activity and NO synthesis therein.

Photic phase-response curves for cycling female mice.

The photic entrainment system is critical for the internal circadian clock to be synchronized by external time cues. In nocturnal rodents, exposure to light during the early subjective night causes a phase delay, whereas it causes a phase advance during the late subjective night. This is represented by a phase-response curve (PRC).

Contribution of the exosome-associated form of secreted endoplasmic reticulum aminopeptidase 1 to exosome-mediated macrophage activation.

Macrophages secrete endoplasmic reticulum aminopeptidase 1 (ERAP1) in response to lipopolysaccharide (LPS) and interferon (IFN)-γ to enhance their phagocytic and nitric oxide (NO) synthetic activities. In this study, we found that a subset of secreted ERAP1 bound to exosomes released from LPS/IFN-γ-treated murine RAW264.7 macrophages compared to untreated cells.