Cholecystokinin activation of central satiety centers changes seasonally in a mammalian hibernator

Otis, Jessica P.; Raybould, Helen E.; Carey, Hannah V.

doi:10.1016/j.ygcen.2011.02.024

Cited by 5 publications

(3 citation statements)

References 38 publications

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“…Afterwards, the combination of decreased food intake (despite no change in food availability) and increased locomotor activity and metabolic rates [11] results in a decrease in body mass. Such seasonal regulation of feeding behavior and satiety signals has already been demonstrated in hibernating species and seems to be controlled through modifications in hormonal signaling [42] and/or the gut-brain axis [43]. The reduction in RER in LW (Figure 4C) testifies that oxidative metabolism in LW animals is essentially fueled by the mobilization of fat stores instead of food carbs.…”

Section: Liver Metabolism In Lw Is Sustained By Mobilization Of Perip...supporting

confidence: 60%

Molecular Liver Fingerprint Reflects the Seasonal Physiology of the Grey Mouse Lemur (Microcebus murinus) during Winter

Chazarin

Benhaim-Delarbre

Brun

et al. 2022

IJMS

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Grey mouse lemurs (Microcebus murinus) are primates that respond to environmental energetic constraints through strong physiological seasonality. They notably fatten during early winter (EW), and mobilize their lipid reserves while developing glucose intolerance during late winter (LW), when food availability is low. To decipher how the hepatic mechanisms may support such metabolic flexibility, we analyzed the liver proteome of adult captive male mouse lemurs, whose seasonal regulations are comparable to their wild counterparts. We highlight profound hepatic changes that reflect fat accretion in EW at the whole-body level, without triggering an ectopic storage of fat in the liver, however. Moreover, molecular regulations are consistent with the decrease in liver glucose utilization in LW, and therefore with reduced tolerance to glucose. However, no major regulation was seen in insulin signaling/resistance pathways. Fat mobilization in LW appeared possibly linked to the reactivation of the reproductive system while enhanced liver detoxification may reflect an anticipation to return to summer levels of food intake. Overall, these results show that the physiology of mouse lemurs during winter relies on solid molecular foundations in liver processes to adapt fuel partitioning while opposing the development of a pathological state despite large lipid fluxes.

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Section: Liver Metabolism In Lw Is Sustained By Mobilization Of Perip...supporting

confidence: 60%

Molecular Liver Fingerprint Reflects the Seasonal Physiology of the Grey Mouse Lemur (Microcebus murinus) during Winter

Chazarin

Benhaim-Delarbre

Brun

et al. 2022

IJMS

View full text Add to dashboard Cite

show abstract

“…Afterwards, the combination of decreased food intake (despite no change in food availability) and increased locomotor activity and metabolic rates [11] results in a decrease in body mass. Such seasonal regulation of feeding behavior and satiety signals has already been demonstrated in hibernating species and seems to be controlled through modifications in hormonal signaling [45] and/or the gutbrain axis [46]. The reduction in RER in LW (Figure 4C) testifies that oxidative metabolism in LW animals is essentially fueled from the mobilization of fat stores instead of food carbs.…”

Section: Massive Fattening Does Not Induce a Pathological State As Witnessed By Liver Responsesupporting

confidence: 60%

Molecular liver fingerprint reflects the seasonal physiology of the grey mouse lemur (Microcebus murinus) during winter

Chazarin

Benhaim-Delarbre

Brun

et al. 2021

Preprint

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Grey mouse lemurs (Microcebus murinus) are a primate species exhibiting strong physiological seasonality in response to environmental energetic constraint. They notably store large amounts of lipids during early winter (EW), which are thereafter mobilized during late winter (LW), when food availability is low. In addition, they develop glucose intolerance in LW only. To decipher how the hepatic mechanisms may support such metabolic flexibility, we analyzed the liver proteome of adult captive male mouse lemurs, which seasonal regulations of metabolism and reproduction are comparable to their wild counterparts, during the phases of either constitution or use of fat reserves. We highlight profound changes that reflect fat accretion in EW at the whole-body level, however, without triggering an ectopic storage of fat in the liver. Moreover, molecular regulations would be in line with the lowering of liver glucose utilization in LW, and thus with reduced tolerance to glucose. However, no major regulation was seen in insulin signaling/resistance pathways, which suggests that glucose intolerance does not reach a pathological stage. Finally, fat mobilization in LW appeared possibly linked to reactivation of the reproductive system and enhanced liver detoxification may reflect an anticipation to return to summer levels of food intake. Altogether, these results show that the physiology of mouse lemurs during winter relies on solid molecular foundations in liver processes to adapt fuel partitioning while avoiding reaching a pathological state despite large lipid fluxes. This work emphasizes how the mouse lemur is of primary interest for identifying molecular mechanisms relevant to biomedical field.

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“…In non-hibernators, CCK acts synergistically with leptin to potentiate its anorexigenic effect (Taché and Stengel 2011). Activation of NTS neurons in response to exogenous CCK varies seasonally in ground squirrels, with a decrease in sensitivity from spring through summer (Otis et al 2011). This suggests that seasonal changes in sensitivity of NTS neurons to CCK may influence appetite in the active phase of the hibernation cycle.…”

Section: Leptin and Its Role In Food Intakementioning

confidence: 99%

The regulation of food intake in mammalian hibernators: a review

Florant

Healy

2011

J Comp Physiol B

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One of the most profound hallmarks of mammalian hibernation is the dramatic reduction in food intake during the winter months. Several species of hibernator completely cease food intake (aphagia) for nearly 7 months regardless of ambient temperature and in many cases, whether or not food is available to them. Food intake regulation has been studied in mammals that hibernate for over 50 years and still little is known about the physiological mechanisms that control this important behavior in hibernators. It is well known from lesion experiments in non-hibernators that the hypothalamus is the main brain region controlling food intake and therefore body mass. In hibernators, the regulation of food intake and body mass is presumably governed by a circannual rhythm since there is a clear seasonal rhythm to food intake: animals increase food intake in the summer and early autumn, food intake declines in autumn and actually ceases in winter in many species, and resumes again in spring as food becomes available in the environment. Changes in circulating hormones (e.g., leptin, insulin, and ghrelin), nutrients (glucose, and free fatty acids), and cellular enzymes such as AMP-activated protein kinase (AMPK) have been shown to determine the activity of neurons involved in the food intake pathway. Thus, it appears likely that the food intake pathway is controlled by a variety of inputs, but is also acted upon by upstream regulators that are presumably rhythmic in nature. Current research examining the molecular mechanisms and integration of environmental signals (e.g., temperature and light) with these molecular mechanisms will hopefully shed light on how animals can turn off food intake and survive without eating for months on end.

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Cholecystokinin activation of central satiety centers changes seasonally in a mammalian hibernator

Cited by 5 publications

References 38 publications

Molecular Liver Fingerprint Reflects the Seasonal Physiology of the Grey Mouse Lemur (Microcebus murinus) during Winter

Molecular Liver Fingerprint Reflects the Seasonal Physiology of the Grey Mouse Lemur (Microcebus murinus) during Winter

Molecular liver fingerprint reflects the seasonal physiology of the grey mouse lemur (Microcebus murinus) during winter

The regulation of food intake in mammalian hibernators: a review

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