Increased Sensitivity of the Circadian System to Temporal Changes in the Feeding Regime of Spontaneously Hypertensive Rats - A Potential Role for Bmal2 in the Liver

Polidarová, Lenka; Sládek, Martin; Nováková, Marta; Parkanová, Daniela; Sumová, Alena

doi:10.1371/journal.pone.0075690

Cited by 18 publications

(16 citation statements)

References 72 publications

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“…) and oral mucosa (Polidarova et al . ). Interestingly, the phase of expression of the clock genes in humans is in antiphase to that observed in nocturnal species.…”

Section: Discussionmentioning

confidence: 97%

Rapidly alternating photoperiods disrupt central and peripheral rhythmicity and decrease plasma glucose, but do not affect glucose tolerance or insulin secretion in sheep

Varcoe

Gatford

Voultsios

et al. 2014

Experimental Physiology

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New Findings r What is the central question of this study?Disrupting circadian rhythms in rodents perturbs glucose metabolism and increases adiposity. In this study, we asked whether circadian rhythm disruption, induced by exposure of sheep to rapidly alternating photoperiods (RAPs), also disrupts metabolic homeostasis in a large diurnal animal model. r What is the main finding and its importance?Exposure to RAPs disrupted central (melatonin and core body temperature) and peripheral rhythmicity (skeletal muscle clock gene expression). This led to reduced nocturnal plasma glucose concentrations, but did not affect glucose tolerance and glucose-stimulated insulin secretion. These results suggest that RAP-induced circadian rhythm disruption has minimal effect on glucose homeostasis in the sheep.Disrupting circadian rhythms in rodents perturbs glucose metabolism and increases adiposity. To determine whether these effects occur in a large diurnal animal, we assessed the impact of circadian rhythm disruption upon metabolic function in sheep. Adult ewes (n = 7) underwent 3 weeks of a control 12 h light-12 h dark photoperiod, followed by 4 weeks of rapidly alternating photoperiods (RAPs) whereby the time of light exposure was reversed twice each week. Measures of central (melatonin secretion and core body temperature) and peripheral rhythmicity (clock and metabolic gene expression in skeletal muscle) were obtained over 24 h in both conditions. Metabolic homeostasis was assessed by glucose tolerance tests and 24 h glucose and insulin profiles. Melatonin and core body temperature rhythms resynchronized within 2 days of the last photoperiod shift. High-amplitude Bmal1, Clock, Nr1d1, Cry2 and Per3 mRNA rhythms were apparent in skeletal muscle, which were phase advanced by up to 3.5 h at 2 days after the last phase shift, whereas Per1 expression was downregulated at this time. Pparα, Pgc1α and Nampt mRNA were constitutively expressed in both conditions. Nocturnal glucose concentrations were reduced following chronic phase shifts (zeitgeber time 0, −5.5%; zeitgeber time 12, −2.9%; and zeitgeber time 16, −5.7%), whereas plasma insulin, glucose tolerance and glucose-stimulated

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“…) and oral mucosa (Polidarova et al . ). Interestingly, the phase of expression of the clock genes in humans is in antiphase to that observed in nocturnal species.…”

Section: Discussionmentioning

confidence: 97%

Rapidly alternating photoperiods disrupt central and peripheral rhythmicity and decrease plasma glucose, but do not affect glucose tolerance or insulin secretion in sheep

Varcoe

Gatford

Voultsios

et al. 2014

Experimental Physiology

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show abstract

“…; Polidarova et al . , ) and their expression was stable throughout the 24 h period. All of the primer sequences have been reported previously (Sladek et al .…”

Section: Methodsmentioning

confidence: 95%

“…; Polidarova et al . ). In terms of the differences most relevant to the present study, the adult SHR have daily activity/rest cycles that are dampened and phase‐advanced relative to the light/dark cycle (Sladek et al .…”

Section: Introductionmentioning

confidence: 97%

“…) and they are more sensitive to changes in feeding regime (Polidarova et al . ). Additionally, our previous findings (Olejnikova et al .…”

Section: Introductionmentioning

confidence: 97%

“…; Polidarova et al . ), with the latter comprising a strain that SHR were originally bred from (Okamoto & Aoki, ). SHR spontaneously develop pathology in cardiovascular (Conrad et al .…”

Section: Introductionmentioning

confidence: 99%

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Circadian alignment in a foster mother improves the offspring's pathological phenotype

Olejníková¹,

Polidarová²,

Behuliak

et al. 2018

The Journal of Physiology

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In mammals, the mother-offspring interaction is essential for health later in adulthood. Maternal care is determined by the circadian phenotype of the mother. The impact of altered timing and quality of maternal care on the circadian system was assessed using a cross-strain fostering approach, with 'abnormal' (i.e. circadian misaligned) care being represented by spontaneously hypertensive rats (SHR) and 'normal' care by Wistar rats. The SHR mothers worsened synchrony of the central clock in the suprachiasmatic nuclei with the light/dark cycle in Wistar rat pups, although this effect disappeared after weaning. The maternal care provided by Wistar rat mothers to SHR pups facilitated the development of amplitudes of the Bmal1 expression rhythm in the suprachiasmatic nuclei of the hypothalamus, as well as the clock-driven activity/rest rhythm and its entrainment to the external light/dark cycle. The peripheral clocks in the liver and colon responded robustly to cross-strain fostering; the circadian phenotype of the Wistar rat foster mother remedied the dampened amplitudes of the colonic clock in SHR pups and improved their cardiovascular functions. In general, the more intensive maternal care of the Wistar rat mothers improved most of the parameters of the abnormal SHR circadian phenotype in adulthood; conversely, the less frequent maternal care of the SHR mothers worsened these parameters in the Wistar rat during the early developmental stages. Altogether, our data provide compelling evidence that the circadian phenotype of a foster mother may positively and negatively affect the regulatory mechanisms of various physiological parameters, even if the pathological symptoms are genetically programmed.

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The role of clock genes and circadian rhythm in the development of cardiovascular diseases

Takeda

Maemura

2015

Cell. Mol. Life Sci.

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The time of onset of cardiovascular disorders such as myocardial infarctions or ventricular arrhythmias exhibits a circadian rhythm. Diurnal variations in autonomic nervous activity, plasma cortisol level or renin-angiotensin activity underlie the pathogenesis of cardiovascular diseases. Transcriptional-translational feedback loop of the clock genes constitute a molecular clock system. In addition to the central clock in the suprachiasmatic nucleus, clock genes are also expressed in a circadian fashion in each organ to make up the peripheral clock. The peripheral clock seems to be beneficial for anticipating external stimuli and thus contributes to the maintenance of organ homeostasis. Loss of synchronization between the central and peripheral clocks also augments disease progression. Moreover, accumulating evidence shows that clock genes affect inflammatory and intracellular metabolic signaling. Elucidating the roles of the molecular clock in cardiovascular pathology through the identification of clock controlled genes will help to establish a novel therapeutic approach for cardiovascular disorders.

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Increased Sensitivity of the Circadian System to Temporal Changes in the Feeding Regime of Spontaneously Hypertensive Rats - A Potential Role for Bmal2 in the Liver

Cited by 18 publications

References 72 publications

Rapidly alternating photoperiods disrupt central and peripheral rhythmicity and decrease plasma glucose, but do not affect glucose tolerance or insulin secretion in sheep

Rapidly alternating photoperiods disrupt central and peripheral rhythmicity and decrease plasma glucose, but do not affect glucose tolerance or insulin secretion in sheep

Circadian alignment in a foster mother improves the offspring's pathological phenotype

The role of clock genes and circadian rhythm in the development of cardiovascular diseases

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