Effect of diet and ovariectomy on adipose tissue cellularity in mice

Pallier, E.; Aubert, Roberte; Lemonnier, Daniel

doi:10.1051/rnd:19800404

Cited by 22 publications

(18 citation statements)

References 11 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…1,2 E 2 replacement therapy can normalize these abnormalities by reducing food intake and increasing metabolic expenditure. 1,2 This anorexigenic role of E 2 has also been shown in rodent studies. [3][4][5] Ovariectomized rats display increase in food intake and adipose tissue deposition, which can be readily reversed with the re-introduction of E 2 .…”

Section: Introductionmentioning

confidence: 79%

Estrogen inhibits NPY secretion through membrane-associated estrogen receptor (ER)-α in clonal, immortalized hypothalamic neurons

Dhillon

Belsham

2010

Int J Obes

View full text Add to dashboard Cite

Objective: Estrogen (E 2 ) has an inhibitory effect on food intake by acting centrally in the hypothalamus, although it is not clear which hypothalamic neurons are involved in this process. Earlier studies from our lab and others have implicated neuropeptide Y (NPY) as an important central anorexigenic target of E 2 . This study was designed to investigate whether E 2 can directly regulate NPY secretion and examine the cellular mechanisms and receptors responsible for this anorexigenic action of E 2 . Design: Clonal, murine, hypothalamic neuronal cell models, mHypoE-42 and mHypoA-2/12, were investigated for NPY secretory responses to 17b-estradiol (E 2 ) in the presence or absence of pharmacological inhibitors directed against the phosphatidylinositol-3-kinase (PI3K), mitogen-activated protein kinase (MAPK) and AMP-activated kinase (AMPK) pathways or to estrogen receptor (ER) specific agonists/antagonists. Measurements: The presence of hypothalamic markers and characterization of neuronal cell lines was completed with polymerase chain reaction. NPY levels were measured using an enzyme immunoassay (EIA). The expression of ER-a and caveolin-1 was analyzed using immunocytochemistry. Results: E 2 significantly decreased NPY secretion in both the mHypoE-42 and mHypoA-2/12 neurons. The E 2 -mediated repression of NPY secretion in the mHypoE-42 and mHypoA-2/12 neurons required ER-a, but not ER-b, as shown by studies using an ER-specific agonist/antagonists. Additionally, using immunocytochemistry we detected colocalization of ER-a and the membrane-associated signaling protein caveolin-1. Importantly, using E 2 -conjugated bovine serum albumin (E 2 -BSA) and ER antagonists, we were able to show that the E 2 -mediated decrease in NPY secretion occurred through membrane-bound ER-a. Finally, using a combination of pharmacological inhibitors, we found that inhibition of the PI3K or AMPK pathway blocked the E 2 -mediated decrease in NPY secretion. Conclusion: These findings indicate that the central anorexigenic action of E 2 occurs at least partially through hypothalamic NPY-synthesizing neurons. This regulation of NPY secretion occurs through rapid signaling mechanisms through membrane bound ER-a.

show abstract

Section: Introductionmentioning

confidence: 79%

Estrogen inhibits NPY secretion through membrane-associated estrogen receptor (ER)-α in clonal, immortalized hypothalamic neurons

Dhillon

Belsham

2010

Int J Obes

View full text Add to dashboard Cite

show abstract

“…Moreover, our findings are in line with the metabolic functions of estrogen and NPY. While estrogen has been demonstrated to exert anorexigenic effects (85,100,195,198), NPY is a known orexigen (44,231,232). Indeed, several lines of evidence suggest that estrogen mediates its anorexigenic effects through hypothalamic NPY (25,218).…”

Section: New Insights Into Reproduction Using Neuronal Cell Modelsmentioning

confidence: 96%

Immortalized neurons for the study of hypothalamic function

Dalvi

Nazarians-Armavil

Tung

et al. 2011

American Journal of Physiology-Regulatory, Integrative and Comp

View full text Add to dashboard Cite

The hypothalamus is a vital part of the central nervous system: it harbors control systems implicated in regulation of a wide range of homeostatic processes, including energy balance and reproduction. Structurally, the hypothalamus is a complex neuroendocrine tissue composed of a multitude of unique neuronal cell types that express a number of neuromodulators, including hormones, classical neurotransmitters, and specific neuropeptides that play a critical role in mediating hypothalamic function. However, neuropeptide and receptor gene expression, second messenger activation, and electrophysiological and secretory properties of these hypothalamic neurons are not yet fully defined, primarily because the heterogeneity and complex neuronal architecture of the neuroendocrine hypothalamus make such studies challenging to perform in vivo. To circumvent this problem, our research group recently generated embryonic- and adult-derived hypothalamic neuronal cell models by utilizing the novel molecular techniques of ciliary neurotrophic factor-induced neurogenesis and SV40 T antigen transfer to primary hypothalamic neuronal cell cultures. Significant research with these cell lines has demonstrated their value as a potential tool for use in molecular genetic analysis of hypothalamic neuronal function. Insights gained from hypothalamic immortalized cells used in conjunction with in vivo models will enhance our understanding of hypothalamic functions such as neurogenesis, neuronal plasticity, glucose sensing, energy homeostasis, circadian rhythms, and reproduction. This review discusses the generation and use of hypothalamic cell models to study mechanisms underlying the function of individual hypothalamic neurons and to gain a more complete understanding of the overall physiology of the hypothalamus.

show abstract

“…This view is supported by the work of Beretta et al who found that central administration of an adeno-associated viral vector encoding LIF did not affect UCP1 protein expression (11), whereas it has been reported that LIF decreases food intake (24), suggesting that LIF induces weight loss mainly through reduced appetite. Ovariectomy, on the other hand, has been reported to increase food intake in mice (25).…”

Section: Discussionmentioning

confidence: 99%

Leukemia inhibitory factor reduces body fat mass in ovariectomized mice

Jansson¹,

Movérare‐Skrtic²,

Berndtsson³

et al. 2006

eur j endocrinol

View full text Add to dashboard Cite

Objective: Ovariectomized (OVX) mice are known to gain body fat while exposure to estrogens decreases fat mass. We have previously shown that estrogen replacement therapy enhances the expression of receptors for the cytokine, leukemia inhibitory factor (LIF). LIF and other cytokines acting via the gp130 signal transducing receptor have been reported to decrease obesity. In the present study, we investigated whether LIF treatment can reduce obesity in OVX mice. Design: Eight-week-old female C57Bl/6 mice were OVX or sham-operated. The mice were treated with LIF, 30 mg/kg or PBS via daily i.p. injections for 15 days (n ¼ 9-10). Methods: Dual X-ray absorptiometry and computerized tomography. Results: We found that LIF treatment of OVX mice caused a significant reduction in the weight of white fat depots (P ¼ 0.017) and serum leptin levels (P ¼ 0.011). LIF also caused a significant decrease in brown fat mass (P ¼ 0.036). Treatment with LIF decreased thymus weight but did not affect crown-rump length, femur length, trabecular bone mineral density or the weight of several non-fat organs including the uterus. Conclusion: The cytokine, LIF, decreases body fat mass in OVX mice, suggesting that estrogen signaling is not required for this effect.

show abstract

Effect of diet and ovariectomy on adipose tissue cellularity in mice

Cited by 22 publications

References 11 publications

Estrogen inhibits NPY secretion through membrane-associated estrogen receptor (ER)-α in clonal, immortalized hypothalamic neurons

Estrogen inhibits NPY secretion through membrane-associated estrogen receptor (ER)-α in clonal, immortalized hypothalamic neurons

Immortalized neurons for the study of hypothalamic function

Leukemia inhibitory factor reduces body fat mass in ovariectomized mice

Contact Info

Product

Resources

About