Similar Datasets
Project description:Various aspects of physiology and cell function present self-sustained ~24h variations termed circadian rhythms, enabling anticipation and adaptation to the 24-h cycle produced by the Earth’s rotation. The circadian clock system consists of a central clock located in the suprachiasmatic nucleus in the hypothalamus, and peripheral clocks present in distinct tissues. In particular, peripheral clocks in the liver have fundamental roles in maintaining liver homeostasis. Here, we established and characterized a human hepatocyte in vitro system in which human primary hepatocytes displayed self-sustained oscillations independently of external cues a distinguishing feature of circadian clocks. We then used this experimental system to study the impact of circadian oscillations in human liver pathophysiology. By generating hepatocyte circadian transcriptomes, we demonstrated that the transcriptional state of cultured human hepatocytes is dynamic across 24h. Analyses of gene expression data identified a set of cycling genes, including a subset of well-established ‘core clock genes’ and oscillating genes related to inflammation, drug metabolism, and energy homeostasis. We documented a circadian-dependent induction of the pro-inflammatory cytokines IL-1b, IL-6, TNF-a CXCLl1 and CXCL10 triggered by LPS or IFN-b in human hepatocytes. We also demonstrated circadian fluctuations of a subset of drug metabolism enzymes, which regulate drug pharmacokinetics. Among these enzymes, we identified CYP3A4, as one displaying circadian fluctuations at activity levels and a time-dependent induction with rifampin. Finally, we showed the impact of applying chronopharmacotherapy by designing a treatment protocol to minimize atorvastatin and acetaminophen induced hepatotoxicity. Collectively, our findings document that circadian time can influence the magnitude of the inflammatory response in the liver and the efficacy, toxicity, and/or the therapeutic index of drugs.
2024-02-28 | GSE218243 | GEO
Project description:Various aspects of physiology and cell function present self-sustained ~24h variations termed circadian rhythms, enabling anticipation and adaptation to the 24-h cycle produced by the Earth’s rotation. The circadian clock system consists of a central clock located in the suprachiasmatic nucleus in the hypothalamus, and peripheral clocks present in distinct tissues. In particular, peripheral clocks in the liver have fundamental roles in maintaining liver homeostasis. Here, we established and characterized a human hepatocyte in vitro system in which human primary hepatocytes displayed self-sustained oscillations independently of external cues a distinguishing feature of circadian clocks. We then used this experimental system to study the impact of circadian oscillations in human liver pathophysiology. By generating hepatocyte circadian transcriptomes, we demonstrated that the transcriptional state of cultured human hepatocytes is dynamic across 24h. Analyses of gene expression data identified a set of cycling genes, including a subset of well-established ‘core clock genes’ and oscillating genes related to inflammation, drug metabolism, and energy homeostasis. We documented a circadian-dependent induction of the pro-inflammatory cytokines IL-1b, IL-6, TNF-a CXCLl1 and CXCL10 triggered by LPS or IFN-b in human hepatocytes. We also demonstrated circadian fluctuations of a subset of drug metabolism enzymes, which regulate drug pharmacokinetics. Among these enzymes, we identified CYP3A4, as one displaying circadian fluctuations at activity levels and a time-dependent induction with rifampin. Finally, we showed the impact of applying chronopharmacotherapy by designing a treatment protocol to minimize atorvastatin and acetaminophen induced hepatotoxicity. Collectively, our findings document that circadian time can influence the magnitude of the inflammatory response in the liver and the efficacy, toxicity, and/or the therapeutic index of drugs.
2024-02-28 | GSE218242 | GEO
Project description:The liver is one of the most sexually dimorphic organs. The hepatic metabolic pathways that are subject to sexual dimorphism include xenobiotic, amino acid and lipid metabolism. Non-alcoholic fatty liver disease and hepatocellular carcinoma are among diseases with sex-dependent prevalence, progression and outcome. Although male and female livers differ in their abilities to metabolize foreign compounds, including drugs, sex-dependent treatment and pharmacological dynamics are rarely applied in all relevant cases. Therefore, it is important to consider hepatic sexual dimorphism when developing new treatment strategies and to understand the underlying mechanisms in model systems. We isolated primary hepatocytes from male and female C57BL6/N mice and examined the sex-dependent transcriptome, proteome and extracellular metabolome parameters in the course of culturing them for 96 h. The sex-specific gene expression of the general xenobiotic pathway altered and the female-specific expression of Cyp2b13 and Cyp2b9 was significantly reduced during culture. Sex-dependent differences of several signaling pathways increased, including genes related to serotonin and melatonin degradation. Furthermore, the ratios of male and female gene expression were inversed for other pathways, such as amino acid degradation, beta-oxidation, androgen signaling and hepatic steatosis. Because the primary hepatocytes were cultivated without the influence of known regulators of sexual dimorphism, these results suggest currently unknown modulatory mechanisms of sexual dimorphism in vitro. The large sex-dependent differences in the regulation and dynamics of drug metabolism observed during cultivation can have an immense influence on the evaluation of pharmacodynamic processes when conducting initial preclinical trials to investigate potential new drugs.
| S-EPMC8380230 | biostudies-literature
Project description:BACKGROUND: Dysregulation of circadian rhythms can contribute to diseases of lipid metabolism. NAD-dependent deacetylase sirtuin-1(SIRT1) is an important hub which links lipid metabolism with circadian clock by its deacetylation activity depends on intracellular NAD+/NADH content ratio. Hydrogen sulfide (H?S) is an endogenous reductant which can affect the intracellular redox state. Therefore, we hypothesized that exogenous H?S can affect the expression of circadian clock genes mediated by sirt1 thereby affecting body's lipid metabolism. And also because the liver is a typical peripheral circadian clock oscillator that is intimately linked to lipid metabolism. Thus the effect of H?S were observed on 24-hour dynamic expression of 4 central circadian clock genes and sirt1gene in primary cultured hepatocytes. RESULTS: We established a hepatocyte model that showed a circadian rhythm by serum shock method. And detected that the expression level and the peak of circadian clock genes decreased gradually and H?S could maintain the expression and amplitude of circadian clock genes such as Clock, Per2, Bmal1 and Rev-erb?within a certain period time. Accordingly the expression level of sirt1 in H?S group was significantly higher than that in the control group. CONCLUSION: Exogenous reductant H?S maintain the circadian rhythm of clock gene in isolated liver cells. We speculated that H?S has changed NAD+/NADH content ratio in hepatocytes and enhanced the activity of SIRT1 protein directly or indirectly, so as to maintain the rhythm of expression of circadian clock genes, they play a role in the prevention and treatment of lipid metabolism-related disease caused by the biological clock disorders.
| S-EPMC3292508 | biostudies-literature
Project description:Many gut functions are attuned to circadian rhythm. Intestinal group 3 innate lymphoid cells (ILC3s) include NKp46+ and NKp46- subsets, which are RORγt dependent and provide mucosal defense through secretion of interleukin-22 (IL-22) and IL-17. Because ILC3s highly express some key circadian clock genes, we investigated whether ILC3s are also attuned to circadian rhythm. We noted circadian oscillations in the expression of clock and cytokine genes, such as REV-ERBα, IL-22, and IL-17, whereas acute disruption of the circadian rhythm affected cytokine secretion by ILC3s. Because of prominent and rhythmic expression of REV-ERBα in ILC3s, we also investigated the impact of constitutive deletion of REV-ERBα, which has been previously shown to inhibit the expression of a RORγt repressor, NFIL3, while also directly antagonizing DNA binding of RORγt. Development of the NKp46+ ILC3 subset was markedly impaired, with reduced cell numbers, RORγt expression, and IL-22 production in REV-ERBα-deficient mice. The NKp46- ILC3 subsets developed normally, potentially due to compensatory expression of other clock genes, but IL-17 secretion paradoxically increased, probably because RORγt was not antagonized by REV-ERBα. We conclude that ILC3s are attuned to circadian rhythm, but clock regulator REV-ERBα also has circadian-independent impacts on ILC3 development and functions due to its roles in the regulation of RORγt.
| S-EPMC6911370 | biostudies-literature
Project description:The nuclear receptor PXR (Pregnane X rreceptor) mediates the effects of pregnenolone-16alpha-carbonitrile (PCN) on gene transcription. The relative role of PXR and also CAR to the induction response by PCN was studied on cDNA arrays containing 320 (Steroltalk V2) genes (genes involved in cyrcadian rhythm, drug metabolism, cholesterol biosynthesis, sterol synthesis/transport, heme synthesis). Samples from livers of wild type and CAR-/-, PXR-/- or CAR/PXR-/- knockout mice were tested after treatment with PCN for gene expression within the European Framework V program âSteroltalkâ (www.steroltalk.net). Results from these experiments show the complex role of PXR receptor in the expression of genes involved in cyrcadian rhythm, drug metabolism and cholesterol biosynthesis. Animals were injected i.p. 40mg/kg PCN or vehicle (5% DMSO in corn oil). After 12h they were sacrificed and total RNA was isolated from the livers. Pools of untreated samples were mixed in each genetic variant group (wild type and CAR-/-, PXR-/- or CAR/PXR-/-) with the PCN treated ones and hybridized to Steroltalk V2 arrays.
2010-05-16 | E-GEOD-12537 | biostudies-arrayexpress
Project description:Disruption of the circadian clock exacerbates metabolic diseases, including obesity and diabetes. We show that histone deacetylase 3 (HDAC3) recruitment to the genome displays a circadian rhythm in mouse liver. Histone acetylation is inversely related to HDAC3 binding, and this rhythm is lost when HDAC3 is absent. Although amounts of HDAC3 are constant, its genomic recruitment in liver corresponds to the expression pattern of the circadian nuclear receptor Rev-erb?. Rev-erb? colocalizes with HDAC3 near genes regulating lipid metabolism, and deletion of HDAC3 or Rev-erb? in mouse liver causes hepatic steatosis. Thus, genomic recruitment of HDAC3 by Rev-erb? directs a circadian rhythm of histone acetylation and gene expression required for normal hepatic lipid homeostasis.
| S-EPMC3389392 | biostudies-literature
Project description:Synchrony of the mammalian circadian clock is achieved by complex transcriptional and translational feedback loops centered on the BMAL1:CLOCK heterodimer. Modulation of circadian feedback loops is essential for maintaining rhythmicity, yet the role of transcriptional coactivators in driving BMAL1:CLOCK transcriptional networks is largely unexplored. Here, we show diurnal hepatic steroid receptor coactivator 2 (SRC-2) recruitment to the genome that extensively overlaps with the BMAL1 cistrome during the light phase, targeting genes that enrich for circadian and metabolic processes. Notably, SRC-2 ablation impairs wheel-running behavior, alters circadian gene expression in several peripheral tissues, alters the rhythmicity of the hepatic metabolome, and deregulates the synchronization of cell-autonomous metabolites. We identify SRC-2 as a potent coregulator of BMAL1:CLOCK and find that SRC-2 targets itself with BMAL1:CLOCK in a feedforward loop. Collectively, our data suggest that SRC-2 is a transcriptional coactivator of the BMAL1:CLOCK oscillators and establish SRC-2 as a critical positive regulator of the mammalian circadian clock.
| S-EPMC4096300 | biostudies-literature
Project description:The nuclear receptor PXR (Pregnane X rreceptor) mediates the effects of pregnenolone-16alpha-carbonitrile (PCN) on gene transcription. The relative role of PXR and also CAR to the induction response by PCN was studied on cDNA arrays containing 320 (Steroltalk V2) genes (genes involved in cyrcadian rhythm, drug metabolism, cholesterol biosynthesis, sterol synthesis/transport, heme synthesis). Samples from livers of wild type and CAR-/-, PXR-/- or CAR/PXR-/- knockout mice were tested after treatment with PCN for gene expression within the European Framework V program “Steroltalk” (www.steroltalk.net). Results from these experiments show the complex role of PXR receptor in the expression of genes involved in cyrcadian rhythm, drug metabolism and cholesterol biosynthesis.
2008-11-13 | GSE12537 | GEO
Project description:Gut Microbe-Targeted Choline Trimethylamine Lyase Inhibition Improves Obesity Via Rewiring of Host Circadian Rhythms.
| PRJEB48232 | ENA