Dataset Information

Lipocalin 2 deficiency alters estradiol production and estrogen receptor signaling in female mice.

ABSTRACT: We have previously characterized lipocalin 2 (Lcn2) as a new adipokine having a critical role in energy and lipid metabolism in male mice. Previous studies by others have suggested that Lcn2 is a putative target gene of estrogens. In this study, we reported the effect of Lcn2 deficiency on estradiol biosynthesis and estrogen receptor signaling in female Lcn2-deficient (Lcn2-/-) mice. We found that Lcn2 expression in white adipose tissue is gender, depot, and age dependent. In female mice, Lcn2 is predominantly expressed in inguinal adipose tissue but at relatively very low levels in perigonadal depot and ovary. After 22 wk of high-fat diet (HFD) feeding or at old age, Lcn2-/- female mice had significantly reduced levels of serum 17?-estradiol and down-regulated expression of estrogen receptor ? in multiple metabolic tissues. Consistently, the expression of estrogen-regulated genes involved in cholesterol homeostasis, such as liver X receptor ? and low-density lipoprotein receptor was also down-regulated in the adipose tissue of Lcn2-/- mice. These changes were in line with the development of atherogenic dyslipidemia in response to HFD feeding; female Lcn2-/- mice had significantly elevated levels of total cholesterol and low-density lipoprotein cholesterol, whereas reduced high-density lipoprotein cholesterol levels compared with wild-type female mice. Interestingly, when compared with wild-type controls, HFD-fed female Lcn2-/- mice had significantly reduced expression levels of aromatase, a key enzyme regulating estradiol biosynthesis, in adipose tissue. Moreover, Lcn2 deficiency markedly blunted age-related increase in adipose aromatase expression but had no significant impact on age-related reduction in ovarian aromatase expression. Our findings suggest that Lcn2 has a tissue-specific role in adipose estradiol biosynthesis, which may link Lcn2 to obesity- and age-related estradiol production and metabolic complications in females.

SUBMITTER: Guo H

PROVIDER: S-EPMC3281525 | biostudies-literature | 2012 Mar

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Lipocalin 2 deficiency alters estradiol production and estrogen receptor signaling in female mice.

Guo Hong H Zhang Yuanyuan Y Brockman David A DA Hahn Wendy W Bernlohr David A DA Chen Xiaoli X

Endocrinology 20120110 3

We have previously characterized lipocalin 2 (Lcn2) as a new adipokine having a critical role in energy and lipid metabolism in male mice. Previous studies by others have suggested that Lcn2 is a putative target gene of estrogens. In this study, we reported the effect of Lcn2 deficiency on estradiol biosynthesis and estrogen receptor signaling in female Lcn2-deficient (Lcn2-/-) mice. We found that Lcn2 expression in white adipose tissue is gender, depot, and age dependent. In female mice, Lcn2 i ...[more]

PMID: 22234464

Similar Datasets

Project description:Estrogen is atheroprotective and a high-affinity ligand for both known estrogen receptors, ERalpha and ERbeta. However, the role of the ERalpha in early-stage atherosclerosis has not been directly investigated and is incompletely understood. ERalpha-deficient (ERalpha-/-) and wild-type (ERalpha+/+) female mice consuming an atherogenic diet were studied concurrent with estrogen replacement to distinguish the actions of 17beta-estradiol (E(2)) from those of ERalpha on the development of early atherosclerotic lesions. Mice were ovariectomized and implanted with subcutaneous slow-release pellets designed to deliver 6 or 8 mug/day of exogenous 17beta-estradiol (E(2)) for a period of up to 4 months. Ovariectomized mice (OVX) with placebo pellets (E(2)-deficient controls) were compared to mice with endogenous E(2) (intact ovaries) and exogenous E(2). Aortas were analyzed for lesion area, number, and distribution. Lipid and hormone levels were also determined. Compared to OVX, early lesion development was significantly (p < 0.001) attenuated by E(2) with 55-64% reduction in lesion area by endogenous E(2) and >90% reduction by exogenous E(2). Compared to OVX, a decline in lesion number (2- to 4-fold) and lesser predilection (~4-fold) of lesion formation in the proximal aorta also occurred with E(2). Lesion size, development, number, and distribution inversely correlated with circulating plasma E(2) levels. However, atheroprotection was independent of ERalpha status, and E(2) athero-protection in both genotypes was not explained by changes in plasma lipid levels (total cholesterol, triglyceride, and high-density lipoprotein cholesterol). The ERalpha is not essential for endogenous/exogenous E(2)-mediated protection against early-stage atherosclerosis. These observations have potentially significant implications for understanding the molecular and cellular mechanisms and timing of estrogen action in different estrogen receptor (ER) deletion murine models of atherosclerosis, as well as implications to human studies of ER polymorphisms and lipid metabolism. Our findings may contribute to future improved clinical decision-making concerning the use of hormone therapy.

Dataset Information

Lipocalin 2 deficiency alters estradiol production and estrogen receptor signaling in female mice.

Publications

Lipocalin 2 deficiency alters estradiol production and estrogen receptor signaling in female mice.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets