ABSTRACTThyroid hormones (THs) are important regulators of systemic energy metabolism. In the liv... more ABSTRACTThyroid hormones (THs) are important regulators of systemic energy metabolism. In the liver, they stimulate lipid and cholesterol turnover and increase systemic energy bioavailability. It is still unknown how the TH state interacts with the circadian clock, another important regulator of energy metabolism. We addressed this question using a mouse model of hypothyroidism and performed circadian analyses. Low TH levels decreased locomotor activity, food intake, and body temperature mostly in the active phase. Concurrently, liver transcriptome profiling showed only subtle effects compared to elevated TH conditions. Comparative circadian transcriptome profiling revealed alterations in mesor, amplitude, and phase of transcript levels in the livers of low-TH mice. Genes associated with cholesterol uptake, biosynthesis, and bile acid secretion showed reduced mesor. Increased and decreased cholesterol levels in the serum and liver were identified, respectively. Combining data from l...
ObjectiveInternal clocks time behavior and physiology, including the gut microbiome in a circadia... more ObjectiveInternal clocks time behavior and physiology, including the gut microbiome in a circadian (∼24 h) manner. Mismatch between internal and external time, e.g. during shift work, disrupts circadian system coordination promoting the development of obesity and type 2 diabetes (T2D). Conversely, body weight changes induce microbiota dysbiosis. The relationship between circadian disruption and microbiota dysbiosis in metabolic diseases, however, remains largely unknown.MethodsCore and accessory clock gene expression in different gastrointestinal (GI) tissues were determined by qPCR in two different models of circadian disruption - mice with Bmal1 deficiency in the circadian pacemaker, the suprachiasmatic nucleus (Bmal1SCNfl/-), and wild-type mice exposed to simulated shift work (SSW). Body composition and energy balance were evaluated by nuclear magnetic resonance (NMR), bomb calorimetry, food intake and running-wheel activity. Intestinal permeability was measured in an Ussing cham...
In den 1990er-Jahren fuhrten bahnbrechende chirurgische Experimente zur Identifikation des SCNs a... more In den 1990er-Jahren fuhrten bahnbrechende chirurgische Experimente zur Identifikation des SCNs als primarem Schrittmacher des circadianen Systems. Dieser kommuniziert uber neuronale und kreislaufvermittelte Signale mit einem Netzwerk von Uhren im ganzen Korper. Diese Netzwerke der circadianen Uhren und Rhythmen sind ein vielversprechender Gegenstand zur Vorbeugung und Behandlung von vielen chronischen Krankheiten, darunter Stoffwechsel- und Schlafstorungen, aber auch psychische Krankheiten wie die (Winter-)Depression oder sogar Krebs. Es wird dabei immer deutlicher, dass Zell- und Gewebeuhren unseres Korpers nicht unabhangig voneinander funktionieren. Ansatze zur circadianen Taktstabilisierung wie die Licht- oder Melatonin-Therapie mit dem Ziel, so die gesamte Netzwerkorganisation des Uhrensystems zu beeinflussen, konnen die Pravention oder Behandlung von Krankheiten erleichtern.
ABSTRACTThyroid hormones (THs) are important regulators of systemic energy metabolism. In the liv... more ABSTRACTThyroid hormones (THs) are important regulators of systemic energy metabolism. In the liver, they stimulate lipid and cholesterol turnover and increase systemic energy bioavailability. It is still unknown how the TH state interacts with the circadian clock, another important regulator of energy metabolism. We addressed this question using a mouse model of hypothyroidism and performed circadian analyses. Low TH levels decreased locomotor activity, food intake, and body temperature mostly in the active phase. Concurrently, liver transcriptome profiling showed only subtle effects compared to elevated TH conditions. Comparative circadian transcriptome profiling revealed alterations in mesor, amplitude, and phase of transcript levels in the livers of low-TH mice. Genes associated with cholesterol uptake, biosynthesis, and bile acid secretion showed reduced mesor. Increased and decreased cholesterol levels in the serum and liver were identified, respectively. Combining data from l...
ObjectiveInternal clocks time behavior and physiology, including the gut microbiome in a circadia... more ObjectiveInternal clocks time behavior and physiology, including the gut microbiome in a circadian (∼24 h) manner. Mismatch between internal and external time, e.g. during shift work, disrupts circadian system coordination promoting the development of obesity and type 2 diabetes (T2D). Conversely, body weight changes induce microbiota dysbiosis. The relationship between circadian disruption and microbiota dysbiosis in metabolic diseases, however, remains largely unknown.MethodsCore and accessory clock gene expression in different gastrointestinal (GI) tissues were determined by qPCR in two different models of circadian disruption - mice with Bmal1 deficiency in the circadian pacemaker, the suprachiasmatic nucleus (Bmal1SCNfl/-), and wild-type mice exposed to simulated shift work (SSW). Body composition and energy balance were evaluated by nuclear magnetic resonance (NMR), bomb calorimetry, food intake and running-wheel activity. Intestinal permeability was measured in an Ussing cham...
In den 1990er-Jahren fuhrten bahnbrechende chirurgische Experimente zur Identifikation des SCNs a... more In den 1990er-Jahren fuhrten bahnbrechende chirurgische Experimente zur Identifikation des SCNs als primarem Schrittmacher des circadianen Systems. Dieser kommuniziert uber neuronale und kreislaufvermittelte Signale mit einem Netzwerk von Uhren im ganzen Korper. Diese Netzwerke der circadianen Uhren und Rhythmen sind ein vielversprechender Gegenstand zur Vorbeugung und Behandlung von vielen chronischen Krankheiten, darunter Stoffwechsel- und Schlafstorungen, aber auch psychische Krankheiten wie die (Winter-)Depression oder sogar Krebs. Es wird dabei immer deutlicher, dass Zell- und Gewebeuhren unseres Korpers nicht unabhangig voneinander funktionieren. Ansatze zur circadianen Taktstabilisierung wie die Licht- oder Melatonin-Therapie mit dem Ziel, so die gesamte Netzwerkorganisation des Uhrensystems zu beeinflussen, konnen die Pravention oder Behandlung von Krankheiten erleichtern.
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