REV-ERBα and its paralog, REV-ERBβ, encoded by and genes, are key nuclear receptors that link the circadian timing system and metabolic homeostasis. Since heme is an endogenous ligand, REV-ERBs have been considered key components of the circadian molecular clock and can be pharmacologically targeted to treat various circadian rhythm-related diseases, such as cardiometabolic, inflammatory, and neuropsychiatric diseases, as well as cancer. REV-ERBs are believed to be functionally redundant and compensatory, although they often affect the expression of gene subsets in an isoform-specific manner.
View Article and Find Full Text PDFAdrenal corticosteroid biosynthesis dysregulation can give rise to various pathological conditions, such as Cushing's syndrome, a disorder characterized by the sustained and excessive production of cortisol. Despite the development of several classes of steroidogenesis inhibitors to treat human diseases associated with cortisol overproduction, their use is limited by insufficient efficacy, adverse effects, and/or tolerability. Recently, we identified a series of benzimidazolylurea derivatives, including the representative compound CJ28, as novel cortisol biosynthesis inhibitors [1].
View Article and Find Full Text PDFAims: Dysregulation of adrenocortical steroid (corticosteroids) biosynthesis leads to pathological conditions such as Cushing's syndrome. Although several classes of steroid biosynthesis inhibitors have been developed to treat cortisol overproduction, limitations such as insufficient efficacy, adverse effects, and/or tolerability still remain. The present study aimed to develop a new class of small molecules that inhibit cortisol production, and investigated their putative modes of action.
View Article and Find Full Text PDFNicotinamide adenine dinucleotide (NAD) is an essential cofactor of critical enzymes including protein deacetylase sirtuins/SIRTs and its levels in mammalian cells rely on the nicotinamide phosphoribosyltransferase (NAMPT)-mediated salvage pathway. Intracellular NAMPT (iNAMPT) is secreted and found in the blood as extracellular NAMPT (eNAMPT). In the liver, the iNAMPT-NAD axis oscillates in a circadian manner and regulates the cellular clockwork.
View Article and Find Full Text PDFMost physiological functions exhibit circadian rhythmicity that is partly regulated by the molecular circadian clock. Herein, we investigated the relationship between the circadian clock and chronic kidney disease (CKD). The role of the clock gene in adenine-induced CKD and the mechanisms of interaction were investigated in mice in which Bmal1, the master regulator of the clock gene, was knocked out, and Bmal1 knockout (KO) tubule cells.
View Article and Find Full Text PDFChronic stress contributes to the risk of developing depression; the habenula, a nucleus in epithalamus, is associated with many neuropsychiatric disorders. Using genome-wide gene expression analysis, we analyzed the transcriptome of the habenula in rats exposed to chronic restraint stress for 14 days. We identified 379 differentially expressed genes (DEGs) that were affected by chronic stress.
View Article and Find Full Text PDFCircadian dysfunction is closely associated with an increased risk of various diseases. Considering that molecular clock machinery serves as an intrinsic time-keeping system underlying the circadian rhythm of biological processes, the modulation of the molecular clock machinery is an attractive therapeutic target with novel mechanisms of action. Based on the previous structure-activity relationship study of small molecule cryptochrome (CRY) inhibitors possessing an ethoxypropanoic acid moiety, non-ethoxypropanoic acid-type inhibitors have been developed by bioisosteric replacement.
View Article and Find Full Text PDFMammalian embryos exhibit a transition from head morphogenesis to trunk elongation to meet the demand of axial elongation. The caudal neural tube (NT) is formed with neural progenitors (NPCs) derived from neuromesodermal progenitors localized at the tail tip. However, the molecular and cellular basis of elongating NT morphogenesis is yet elusive.
View Article and Find Full Text PDFThe sinus node (SN) is located at the apex of the cardiac conduction system, and SN dysfunction (SND)-characterized by electrical remodeling-is generally attributed to idiopathic fibrosis or ischemic injuries in the SN. SND is associated with increased risk of cardiovascular disorders, including syncope, heart failure, and atrial arrhythmias, particularly atrial fibrillation. One of the histological SND hallmarks is degenerative atrial remodeling that is associated with conduction abnormalities and increased right atrial refractoriness.
View Article and Find Full Text PDFMaternal stress has long-lasting influences on the brain functions of offspring, and several brain regions have been proposed to mediate such programming. Although perinatal programming of crosstalk between the circadian and stress systems has been proposed, the functional consequences of prenatal stress on the circadian system and the underlying mechanisms remain largely unknown. Therefore, we investigated whether exposing pregnant mice to chronic restraint stress had prolonged effects on the suprachiasmatic nucleus (SCN), which bears the central pacemaker for mammalian circadian rhythms, of offspring.
View Article and Find Full Text PDFIntroduction: Synchronous and pulsatile neural activation of kisspeptin neurons in the arcuate nucleus (ARN) are important components of the gonadotropin-releasing hormone pulse generator, the final common pathway for central regulation of mammalian reproduction. However, whether ARN kisspeptin neurons can intrinsically generate self-sustained synchronous oscillations from the early neonatal period and how they are regulated remain unclear.
Objective: This study aimed to examine the endogenous rhythmicity of ARN kisspeptin neurons and its neural regulation using a neonatal organotypic slice culture model.
Despite the established comorbidity between mood disorders and abnormal eating behaviors, the underlying molecular mechanism and therapeutics remain to be resolved. Here, we show that a spexin-based galanin receptor type 2 agonist (SG2A) simultaneously normalized mood behaviors and body weight in corticosterone pellet-implanted (CORTI) mice, which are underweight and exhibit signs of anhedonia, increased anxiety, and depression. Administration of SG2A into the lateral ventricle produced antidepressive and anxiolytic effects in CORTI mice.
View Article and Find Full Text PDF5-HT receptor (5-HTR) is implicated in cognitive dysfunction, mood disorder, psychosis, and eating disorders. However, despite its significant role in regulating the brain functions, regulation of 5-HTR at the molecular level is poorly understood. Here, using yeast two-hybrid assay, we found that human 5-HTR directly binds to neuro-oncological ventral antigen 1 (Nova-1), a brain-enriched splicing regulator.
View Article and Find Full Text PDFCircadian rhythms regulate many biological processes and play fundamental roles in behavior, physiology, and metabolism. Such periodicity is critical for homeostasis because disruption or misalignment of the intrinsic rhythms is associated with the onset and progression of various human diseases and often directly leads to pathological states. Since the first identification of mammalian circadian clock genes, numerous genetic and biochemical studies have revealed the molecular basis of these cell-autonomous and self-sustainable rhythms.
View Article and Find Full Text PDFA major mechanism contributing to synaptic plasticity involves alterations in the number of AMPA receptors (AMPARs) expressed at synapses. Hippocampal CA1 synapses, where this process has been most extensively studied, are highly heterogeneous with respect to their probability of neurotransmitter release, P(r). It is unknown whether there is any relationship between the extent of plasticity-related AMPAR trafficking and the initial P(r) of a synapse.
View Article and Find Full Text PDFSarcophaga peregrina (flesh fly) is a frequently found fly species in Palaearctic, Oriental, and Australasian regions that can be used to estimate minimal postmortem intervals important for forensic investigations. Despite its forensic importance, the genome information of S. peregrina has not been fully described.
View Article and Find Full Text PDFObesity (Silver Spring)
September 2018
Objective: Adequate nicotinamide adenine dinucleotide (NAD) content in hypothalamic neurons is critical for the maintenance of normal energy balance and circadian rhythm. In this study, the beneficial metabolic effects of chronic NAD supplementation on diet-induced obesity and obesity-related disruption of diurnal rhythms were examined.
Methods: C57BL/6 mice were fed a high-fat diet (HFD) for 12 weeks and received an intraperitoneal injection of either saline or NAD (1 mg/kg/day) for the last 4 weeks.
Background: Nicotinamide adenine dinucleotide (NAD)-dependent deacetylase SIRT1 is an important regulator of hypothalamic neuronal function. Thus, an adequate hypothalamic NAD content is critical for maintaining normal energy homeostasis.
Methods: We investigated whether NAD supplementation increases hypothalamic NAD levels and affects energy metabolism in mice.
Parkinson's disease (PD) is a neurodegenerative disease characterized by progressive degeneration of dopaminergic (DAergic) neurons, particularly in the substantia nigra (SN). Although circadian dysfunction has been suggested as one of the pathophysiological risk factors for PD, the exact molecular link between the circadian clock and PD remains largely unclear. We have recently demonstrated that REV-ERBα, a circadian nuclear receptor, serves as a key molecular link between the circadian and DAergic systems.
View Article and Find Full Text PDFAdrenal glucocorticoids (GCs) control a wide range of physiological processes, including metabolism, cardiovascular and pulmonary activities, immune and inflammatory responses, and various brain functions. During stress responses, GCs are secreted through activation of the hypothalamic-pituitary-adrenal axis, whereas circulating GC levels in unstressed states follow a robust circadian oscillation with a peak around the onset of the active period of a day. A recent advance in chronobiological research has revealed that multiple regulatory mechanisms, along with classical neuroendocrine regulation, underlie this GC circadian rhythm.
View Article and Find Full Text PDFAims: We have previously identified a chemical scaffold possessing 2-ethoxypropanoic acid (designated as KS15) that directly binds to the C-terminal region of cryptochromes (CRYs: CRY1 and CRY2) and enhances E-box-mediated transcription. However, it is still unclear how KS15 impairs the feedback actions of the CRYs and which chemical moieties are functionally important for its actions.
Main Methods: The E-box-mediated transcriptional activities were mainly used to examine the effects of KS15 and its derivatives.
The application of insect evidence to forensic investigations is mainly based on the estimation of postmortem interval and the identification of insect species from samples that are collected from the crime scene. Due to the limited number of expert taxonomists, species identification is one of the major barriers for crime scene investigators to utilize forensic entomology. Therefore, the molecular identification of species, using mitochondrial cytochrome c oxidase subunit I (COI) gene, has been suggested as an alternative strategy.
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