Clock is important for food and circadian regulation of macronutrient absorption in mice

Pan, Xiaoyue; Hussain, M. Mahmood

doi:10.1194/jlr.m900085-jlr200

Cited by 187 publications

(229 citation statements)

References 61 publications

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“…`äçÅâ animals develop obesity combined with increased levels of cholesterol, triglycerides, glucose and leptin, and a decrease in insulin secretion (Turek=et alK, 2005). Additionally, these mice absorb more lipids and carbohydrates than peptides via the intestine, most likely due to a lack of cyclic nutrient transport proteins (Pan and Hussain, 2009). Both, `äçÅâ mutant and _ã~äN deficient mice show impaired gluconeogenesis, glucose tolerance and insulin sensitivity (Rudic= et alK, 2004).…”

Section: Circadian Control Of Metabolismmentioning

confidence: 99%

A Time to Fast, a Time to Feast: The Crosstalk between Metabolism and the Circadian Clock

Kovac

Husse

Oster

2009

Molecules and Cells

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The cyclic environmental conditions brought about by the 24 h rotation of the earth have allowed the evolution of endogenous circadian clocks that control the temporal alignment of behaviour and physiology, including the uptake and processing of nutrients. Both metabolic and circadian regulatory systems are built upon a complex feedback network connecting centres of the central nervous system and different peripheral tissues. Emerging evidence suggests that circadian clock function is closely linked to metabolic homeostasis and that rhythm disruption can contribute to the development of metabolic disease. At the same time, metabolic processes feed back into the circadian clock, affecting clock gene expression and timing of behaviour. In this review, we summarize the experimental evidence for this bimodal interaction, with a focus on the molecular mechanisms mediating this exchange, and outline the implications for clock-based and metabolic diseases.

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Section: Circadian Control Of Metabolismmentioning

confidence: 99%

A Time to Fast, a Time to Feast: The Crosstalk between Metabolism and the Circadian Clock

Kovac

Husse

Oster

2009

Molecules and Cells

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“…showing a clear crypt-to-tip expression gradient along the villi for various AA transporters, including B 0 AT1 (Camargo et al 2009;Dave et al 2004;Tumer et al 2013 Regulatory mechanisms that may mediate these changes include transcriptional activation, RNA stabilization and epigenetic regulation (Douard et al 2008;Dyer et al 1997;Naruhashi et al 2002;Pan and Hussain 2009).…”

Section: Axial Distribution Of Intestinal Ace Ace2 Amino Acid and Pmentioning

confidence: 99%

Human intestine luminal ACE2 and amino acid transporter expression increased by ACE-inhibitors

et al. 2014

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Sodium-dependent neutral amino acid transporter B(0)AT1 (SLC6A19) and imino acid (proline) transporter SIT1 (SLC6A20) are expressed at the luminal membrane of small intestine enterocytes and proximal tubule kidney cells where they exert key functions for amino acid (re)absorption as documented by their role in Hartnup disorder and iminoglycinuria, respectively. Expression of B(0)AT1 was shown in rodent intestine to depend on the presence of the carboxypeptidase angiotensin-converting enzyme 2 (ACE2). This enzyme belongs to the renin-angiotensin system and its expression is induced by treatment with ACE-inhibitors (ACEIs) or angiotensin II AT1 receptor blockers (ARBs) in many rodent tissues. We show here in the Xenopus laevis oocyte expression system that human ACE2 also functionally interacts with SIT1. To investigate in human intestine the potential effect of ACEIs or ARBs on ACE2, we analysed intestinal biopsies taken during routine gastroduodenoscopy and ileocolonoscopy from 46 patients of which 9 were under ACEI and 13 ARB treatment. Analysis of transcript expression by real-time PCR and of proteins by immunofluorescence showed a co-localization of SIT1 and B(0)AT1 with ACE2 in the brush-border membrane of human small intestine enterocytes and a distinct axial expression pattern of the tested gene products along the intestine. Patients treated with ACEIs displayed in comparison with untreated controls increased intestinal mRNA levels of ACE2, peptide transporter PEPT1 (SLC15A1) and AA transporters B(0)AT1 and PAT1 (SLC36A1). This study unravels in human intestine the localization and distribution of intestinal transporters involved in amino acid absorption and suggests that ACEIs impact on their expression. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64

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“…Therefore, these transporters are directly regulated by feeding conditions (87). In Clock mutant mice, peptide transportation was reduced, but lipid absorption was high (21). In contrast, Nocturnin (i.e., clock-regulated deadenylase)-knockout mice showed that lipid absorption was reduced because of reduced chylomicron transit (88).…”

Section: Digestion and Absorptionmentioning

confidence: 99%

Chrono-biology, Chrono-pharmacology, and Chrono-nutrition

Tahara¹,

Shibata²

2014

J Pharmacol Sci

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Molecular mechanisms of the circadian clock systemThe circadian clock system has been widely maintained in many species, from prokaryotes to mammals. "Circadian" means "around [a] day" in Latin, and therefore "circadian rhythm" refers to a cycle of approximate 24 h. The earth rotates once every 24 h, and the circadian system has evolved to adjust functions and behavior to this cycle in order to efficiently utilize sunlight for photosynthesis in the case of plants and cyanobacteria and to obtain food in the case of animals. One of the most important features of our circadian system is that circadian clocks can endogenously maintain time under constant darkness and without external stimuli, suggesting that our body has its own internal clocks. In 1972, Moore and Eichler (1) investigated the effects of destroying the suprachiasmatic nucleus (SCN) in the rat hypothalamus. Their results revealed the loss of sleep-wake cycles and corticosterone rhythms. Since then, the SCN is regarded as the location of the master clock system in mammals. The SCN receives light-dark information directly through the retinal-hypothalamic tract and organizes the local clock in the peripheral tissues through multiple pathways involving neural and hormonal functions (2, 3). The molecular mechanism of the circadian system in mammals has been well studied over the past two decades. The transcriptional-translational feedback loop of the major clock genes Bmal1, Clock, Per1/2, and Cry1/2 is the main component of the circadian system (2) (Fig. 1A). Bmal1 and Clock, which are transcriptional activators, play a positive role in activating the Per and Cry genes through a specific promoter sequence known as the E-box. Per and Cry are translated into proteins in the cytoplasm and are then transported back into the nucleus after interacting with each other, and they subsequently stop their transcription by binding to BMAL1 and CLOCK. Thus, Per and Cry are rhythmically expressed over a 24-h period. This transcriptional regulation induces rhythmic expression of approximately 10% of all genes in each peripheral cell (4 -6). In addition to such transcriptional regulation of the circadian clock, post-transcriptional regulation and translational regulation have recently been reported to play important roles in maintaining circadian rhythms. Genome-wide RNA-seq and Chip-seq analyses found that only 22% of the rhythmically oscillating messenger RNAs are driven by de novo transcription, with RNA polymerase II recruitment and chromatin remodeling also exhibiting such rhythms (7). Furthermore, it was reported that the non-transcriptional redox cycle has a 24-h rhythm in Chrono-biology, Chrono-pharmacology, and Chrono-nutrition Tokyo 162-8480, Japan Received October 25, 2013; Accepted January 5, 2014 Abstract. The circadian clock system in mammals drives many physiological processes including the daily rhythms of sleep-wake behavior, hormonal secretion, and metabolism. This system responds to daily environmental changes, such as the light-dark cycle, food...

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Clock is important for food and circadian regulation of macronutrient absorption in mice

Cited by 187 publications

References 61 publications

A Time to Fast, a Time to Feast: The Crosstalk between Metabolism and the Circadian Clock

A Time to Fast, a Time to Feast: The Crosstalk between Metabolism and the Circadian Clock

Human intestine luminal ACE2 and amino acid transporter expression increased by ACE-inhibitors

Chrono-biology, Chrono-pharmacology, and Chrono-nutrition

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