Abstract:
:Estrogen regulates the function, growth, and proliferation of lactotropes in the pituitary. We report here that low-density lipoprotein (LDL) receptor (LDLR) gene expression and LDL uptake are strongly up-regulated by estrogen in pituitary somatolactotropic GH(3) cells. The uptake of LDL was significantly inhibited by the F-actin-severing drug, swinholide A, indicating that LDL uptake is dependent on the integrity of the cortical actin cytoskeleton in GH(3) cells. We examined whether the estrogen-inducible cytoskeletal linker protein, ezrin, interacts with the LDLR. The LDLR coimmunoprecipitated with ezrin, and fluorescently labeled LDL bound to regions of the cell membrane that colocalized with the active, phosphorylated form of ezrin (phosphoezrin). Evidence for a functional interaction between ezrin and the LDLR was obtained by transient transfection experiments using ezrin-green fluorescent protein (GFP) expression constructs. We observed that transient transfection of GH(3) cells with an ezrin N terminus-GFP dominant-negative construct prevented the uptake of LDL particles, whereas expression of GFP alone or an ezrin C terminus-GFP construct had no effect on LDL uptake. Transfection with the ezrin N terminus dominant- negative construct had no effect on the endocytosis of transferrin. Thus, estrogen stimulates the expression of ezrin and the LDLR in GH(3) cells, which interact physically and functionally to facilitate the endocytosis of LDL. We propose that the up-regulation and interaction of ezrin and the LDLR serves to augment the delivery of cholesterol and other lipids in support of the hypertrophic and proliferative response of cells to estrogen.
journal_name
Endocrinologyjournal_title
Endocrinologyauthors
Smith PM,Cowan A,White BAdoi
10.1210/en.2004-0228subject
Has Abstractpub_date
2004-07-01 00:00:00pages
3075-83issue
7eissn
0013-7227issn
1945-7170pii
en.2004-0228journal_volume
145pub_type
杂志文章相关文献
ENDOCRINOLOGY文献大全abstract::Task3 K(+) channels are highly expressed in the adrenal cortex and contribute to the angiotensin II and K(+) sensitivity of aldosterone-producing glomerulosa cells. Adult Task3(-/-) mice display a partially autonomous aldosterone secretion, subclinical hyperaldosteronism, and salt-sensitive hypertension. Here, we inve...
journal_title:Endocrinology
pub_type: 杂志文章
doi:10.1210/en.2013-1101
更新日期:2013-08-01 00:00:00
abstract::In the present work we describe homologous desensitization of gonadotropin release from pituitary cells in response to short-term exposure to GnRH. Like the release process itself, desensitization requires receptor occupancy by an agonist. In contrast, however, inhibition of LH release by chelation of extracellular ca...
journal_title:Endocrinology
pub_type: 杂志文章
doi:10.1210/endo-112-1-408
更新日期:1983-01-01 00:00:00
abstract::It is widely accepted that expression of protooncogenes is coupled with cellular proliferation and differentiation. Since ACTH stimulates not only steroidogenesis but also cellular proliferation, we investigated whether ACTH affects the expression of c-fos, c-myc, and beta-actin genes. The effect of ACTH on adrenal gl...
journal_title:Endocrinology
pub_type: 杂志文章
doi:10.1210/endo-127-4-1742
更新日期:1990-10-01 00:00:00
abstract::We previously examined the segregation patterns of two polymorphic restriction enzyme sites for EcoRI and HindIII in the 3'-flanking region of human CG-alpha gene in placenta and choriocarcinoma. We observed that a unique combination of restriction sites predominates in choriocarcinoma while this pattern was rare in p...
journal_title:Endocrinology
pub_type: 杂志文章
doi:10.1210/endo-119-5-2124
更新日期:1986-11-01 00:00:00
abstract::Metalloproteinase inhibitors, such as tissue inhibitors of metalloproteinases 1 and 2 (TIMP-1 and -2), play a key role in the regulation of metalloproteinases that modify extracellular matrix composition. Although expression of TIMP-1 within ovarian tissues has been well characterized, little information is available ...
journal_title:Endocrinology
pub_type: 杂志文章
doi:10.1210/endo.136.2.7835290
更新日期:1995-02-01 00:00:00
abstract::We investigated the effect of glucocorticoid on the generation of osteoclasts. In mouse bone marrow culture systems, dexamethasone, a synthetic glucocorticoid analog, enhanced osteoclast-like cell formation induced by 1,25-dihydroxyvitamin D3 [1,25-(OH)2D3] in a dose-dependent manner. Conversely, dexamethasone inhibit...
journal_title:Endocrinology
pub_type: 杂志文章
doi:10.1210/endo.134.3.8119150
更新日期:1994-03-01 00:00:00
abstract::The effects of estrogens, androgens, and glucocorticoids on bone resorption were compared in organ culture. At a concentration of 10(-5) M, corticosterone, testosterone, dihydrotestosterone, dehydroepiandosterone, estradiol, ethinyl estradiol and estrone did not inhibit the release of 45Ca from 19-day fetal rat long b...
journal_title:Endocrinology
pub_type: 杂志文章
doi:10.1210/endo-98-4-1065
更新日期:1976-04-01 00:00:00
abstract::Molecular mechanisms underlying unloading-induced reduction of bone formation have not yet been fully understood. In vitro, Runx2 has been suggested to be involved in mechanical signaling in osteoblasts. However, the roles of Runx2 in vivo during the bone response to mechanical stimuli have not yet been known. The pur...
journal_title:Endocrinology
pub_type: 杂志文章
doi:10.1210/en.2005-1020
更新日期:2006-05-01 00:00:00
abstract::Male and female Wistar-Furth rats bearing the pituitary tumor MtT/W15 had serum GH and PRL levels several hundred-fold higher, and immunoreactive somatomedin levels 3-fold higher, than those of controls. The presence of tumor appeared to have no effect on specific binding of radioiodinated bovine GH to liver microsoma...
journal_title:Endocrinology
pub_type: 杂志文章
doi:10.1210/endo-111-3-1020
更新日期:1982-09-01 00:00:00
abstract::Two corticotropin-releasing factor 2 receptor (CRF2R)-selective peptides have been recently described, urocortin II (also known as stresscopin-related peptide) and urocortin III (stresscopin). We have used urocortin II to evaluate the effects of activation of the CRF2R on skeletal muscle-related physiological processe...
journal_title:Endocrinology
pub_type: 杂志文章
doi:10.1210/en.2003-0271
更新日期:2003-11-01 00:00:00
abstract::Thyroid papillary carcinoma is the most common type of endocrine cancer. It is frequently associated with genetic alterations leading to activation of the MAPK signaling pathway. The two most frequently affected genes, BRAF and RET, are activated by either point mutation or as a result of chromosomal rearrangement. Th...
journal_title:Endocrinology
pub_type: 杂志文章,评审
doi:10.1210/en.2006-0921
更新日期:2007-03-01 00:00:00
abstract::We demonstrated previously that glucocorticoids differentially affect the levels of the two pituitary gonadotropins, LH and FSH, both in vivo and in vitro. In vivo, the effect of glucocorticoids is GnRH independent, indicating a direct action on the gonadotrope, and it leads to selective up-regulation of the pituitary...
journal_title:Endocrinology
pub_type: 杂志文章
doi:10.1210/endo.137.9.8756550
更新日期:1996-09-01 00:00:00
abstract::In contrast to other systems in which angiotensin-II (AII) inhibits adenylyl cyclase, in fetal skin fibroblasts the peptide stimulates cAMP accumulation. The mechanism of this novel effect was studied by analysis of the actions of AII and other regulators on the adenylyl cyclase system in cultured cells. In the presen...
journal_title:Endocrinology
pub_type: 杂志文章
doi:10.1210/endo.131.5.1330500
更新日期:1992-11-01 00:00:00
abstract::We have studied potential mechanisms by which zinc deficiency (ZD) may result in growth impairment in young animals. Dietary-induced ZD in young rats resulted in diminished skeletal growth as measured by tibial epiphyseal width. Treatment with bovine GH (bGH) did not increase skeletal growth suggesting GH resistance r...
journal_title:Endocrinology
pub_type: 杂志文章
doi:10.1210/endo-114-5-1860
更新日期:1984-05-01 00:00:00
abstract::Prior published reports have demonstrated that glucose-oxidized low-density lipoproteins (g-OxLDL) enhance the proliferative response of vascular smooth muscle cells (SMC) to IGF-I. Our previous studies have determined that the regulation of cleavage of integrin-associated protein (IAP) by matrix-metalloprotease-2 (MM...
journal_title:Endocrinology
pub_type: 杂志文章
doi:10.1210/en.2008-1090
更新日期:2009-03-01 00:00:00
abstract::The molecular forms of GnRH in amphibia have not been characterized structurally. An antiserum to mammalian GnRH that shows appreciable cross-reactivity with chicken GnRH-I ([Gln8]GnRH), chicken GnRH-II ([His5,Trp7,Tyr8]GnRH), and salmon GnRH ([Trp7, Leu8]GnRH) was used in a RIA to detect GnRH-related peptides in an e...
journal_title:Endocrinology
pub_type: 杂志文章
doi:10.1210/endo.132.5.8477660
更新日期:1993-05-01 00:00:00
abstract::Animals maintained on retinol (vitamin A-alcohol)-deficient diets exhibit testicular atrophy and loss of the germinal epithelium. Retinoic acid (vitamin A-acid), when fed to retinol-deficient animals, does not prevent these lesions and had thus been thought not to play a role in the tests. Serum testosterone (T) level...
journal_title:Endocrinology
pub_type: 杂志文章
doi:10.1210/endo-108-6-2120
更新日期:1981-06-01 00:00:00
abstract::The expression of genes encoding key hepatic gluconeogenic enzymes, including phosphoenolpyruvate carboxykinase (PEPCK) and glucose-6-phosphatase (G6Pase), is regulated at the transcriptional level by a network of transcription factors and cofactors, including cAMP response element-binding protein (CREB). It has been ...
journal_title:Endocrinology
pub_type: 杂志文章
doi:10.1210/en.2009-0641
更新日期:2010-02-01 00:00:00
abstract::The distribution of peptide YY (PYY)-like immunoreactivity (IR) in rat tissues was determined by specific RIA after extraction with boiled 1 N acetic acid. The high concentration of PYY-IR was observed in the gastrointestinal tract, with concentrations gradually increasing from the duodenum to the end of colon. The co...
journal_title:Endocrinology
pub_type: 杂志文章
doi:10.1210/endo-118-6-2163
更新日期:1986-06-01 00:00:00
abstract::The rat uterine enzyme glycerylphosphorylcholine (GPC) diesterase found in the proestrous secretions was purified and characterized biochemically with respect to its subunit mol wt, native size, pI, and amino acid and carbohydrate composition. The 30-kDa protein was assessed to have a native mol wt of 105 kDa, as dete...
journal_title:Endocrinology
pub_type: 杂志文章
doi:10.1210/endo-129-3-1147
更新日期:1991-09-01 00:00:00
abstract::Amiodarone, a potent antiarrhythmic drug, contains 37.2% iodine by weight and may induce either hypo- or hyperthyroidism. The high iodine content of amiodarone may be responsible for both complications, but a cytotoxic effect of the drug on the thyroid resulting in thyroiditis has been reported. In the present study t...
journal_title:Endocrinology
pub_type: 杂志文章
doi:10.1210/endo.134.5.8156930
更新日期:1994-05-01 00:00:00
abstract::Although tamoxifen (TAM), a selective estrogen receptor modulator, has been widely used in the treatment of hormone-responsive breast cancer, its estrogen-like effect increases the risk of endometrial cancer. However, the molecular mechanisms of TAM-induced endometrial carcinoma still remain unclear. In this report, w...
journal_title:Endocrinology
pub_type: 杂志文章
doi:10.1210/en.2012-1607
更新日期:2013-02-01 00:00:00
abstract::Somatostatin (SRIF) inhibits GH release from rat somatotropes by reducing adenylate cyclase (AC) activity and the free cytosolic calcium concentration ([Ca(2+)](i)). In contrast, we have reported that SRIF can stimulate GH release in vitro from pig somatotropes. Specifically, 10(-7) and 10(-15) M SRIF stimulate GH rel...
journal_title:Endocrinology
pub_type: 杂志文章
doi:10.1210/endo.143.3.8685
更新日期:2002-03-01 00:00:00
abstract::Hyperactive dog thyroids were prepared by repeated TSH stimulation in vivo. Butanol-extractable 125I (BE125I) release in vitro from slices and hormonal secretion in vivo in the thyroid vein was enhanced. Apical pseudopods and colloid droplets were very infrequent in such hyperactive thyroids. Moreover, BE125I release ...
journal_title:Endocrinology
pub_type: 杂志文章
doi:10.1210/endo-103-5-1834
更新日期:1978-11-01 00:00:00
abstract::Peroxisome proliferator activated receptor (PPARγ) is a nuclear receptor transcription factor that regulates adipogenesis and energy homeostasis. Recent studies suggest PPARγ may mediate some of its metabolic effects through actions in the brain. We used a Cre-recombinase-dependent (using NestinCre) conditionally acti...
journal_title:Endocrinology
pub_type: 杂志文章
doi:10.1210/en.2016-1524
更新日期:2016-11-01 00:00:00
abstract::Liver X receptors (LXRs) are nuclear receptors with established roles in cholesterol, lipid, and carbohydrate metabolism, although their function in adipocytes is not well characterized. Increased adipose tissue mass in obesity is associated with increased adipocyte lipolysis. Fatty acids (FA) generated by lipolysis c...
journal_title:Endocrinology
pub_type: 杂志文章
doi:10.1210/en.2009-0676
更新日期:2009-09-01 00:00:00
abstract::Light and electron microscopic triple immunostaining was performed on coronal vibratome sections prepared from the hypothalamus of ovariectomized (OVX) and OVX plus estrogen-treated African green monkeys (Cercopithecus aethiops). Immunoreactivity for progesterone receptors (PRs) and neuropeptide-Y (NPY) was visualized...
journal_title:Endocrinology
pub_type: 杂志文章
doi:10.1210/endo.133.1.8100520
更新日期:1993-07-01 00:00:00
abstract::In the Syrian hamster, a sharp peak in pineal melatonin occurs toward the end of the dark period. In the present communication, we describe characteristics of this rhythm. First, the time of the initial increase in pineal melatonin is not altered by daily melatonin injections that induce gonadal regression. Second, th...
journal_title:Endocrinology
pub_type: 杂志文章
doi:10.1210/endo-107-5-1525
更新日期:1980-11-01 00:00:00
abstract::The role of PRL in mammalian salt and water balance remains controversial. To avoid the methodological problems of exogenous PRL administration, endogenous hyperprolactinemia was established in normal rats by implantation of extra anterior pituitary glands under the kidney capsule. To eliminate excess glucocorticoid s...
journal_title:Endocrinology
pub_type: 杂志文章
doi:10.1210/endo-118-4-1519
更新日期:1986-04-01 00:00:00
abstract::GH-releasing factor (GRF) is a hypothalamic peptide that stimulates the secretion of pituitary GH. The possibility of feedback effects of GRF within the central nervous system was studied in conscious freely moving male rats with indwelling iv and intracerebroventricular (icv) cannulae. Animals were injected icv or iv...
journal_title:Endocrinology
pub_type: 杂志文章
doi:10.1210/endo-118-5-1872
更新日期:1986-05-01 00:00:00