Cultured gallbladder epithelial cells synthesize apolipoproteins A-I and E

2003 ◽  
Vol 285 (3) ◽  
pp. G630-G641 ◽  
Author(s):  
Jin Lee ◽  
Aimee Tauscher ◽  
Dong Wan Seo ◽  
John F. Oram ◽  
Rahul Kuver
Keyword(s):  
Epithelial Cells ◽  
Intracellular Trafficking ◽  
Cholesterol Efflux ◽  
Hormone Receptors ◽  
Gallstone Formation ◽  
Retinoid X Receptor ◽  
Biliary Cholesterol ◽  
Cholesterol Uptake ◽  
Model Bile ◽  
Apoe Mrna

Gallbladder epithelial cells (GBEC) are exposed to high and fluctuating concentrations of biliary cholesterol on their apical (AP) surface. GBEC absorb and efflux cholesterol, but the mechanisms of cholesterol uptake, intracellular trafficking, and efflux in these cells are not known. We previously reported that ATP binding cassette (ABC)A1 mediates basolateral (BL) cholesterol efflux in cultured polarized GBEC. In addition, the nuclear hormone receptors liver X receptor (LXR)α and retinoid X receptor (RXR) mediate both AP and BL cholesterol efflux. An interesting finding from our previous study was that apolipoprotein (apo)A-I applied to the AP surfaces of cells elicited BL ABCA1-mediated cholesterol efflux. Because ABCA1-mediated cholesterol efflux requires the presence of a cholesterol acceptor, we hypothesized that GBEC synthesize and secrete endogenous apo into the BL compartment. Here, we demonstrate that cholesterol loading of cells with model bile and AP apoA-I treatment is associated with an increase in the synthesis of apoE mRNA and protein. Furthermore, apoE is secreted into the BL compartment. LXRα/RXR ligands stimulate the synthesis of endogenous apoA-I mRNA and protein, as well as apoE mRNA. BL secretion of apoA-I is elicited by LXRα/RXR ligands. Therefore, GBEC synthesize apoA-I and -E and efflux cholesterol using ABCA1- and non-ABCA1- mediated pathways. These processes may alter gallbladder biliary cholesterol concentrations and thereby influence gallstone formation.

scholarly journals Polarized cholesterol and phospholipid efflux in cultured gall-bladder epithelial cells: evidence for an ABCA1-mediated pathway

2002 ◽  
Vol 364 (2) ◽  
pp. 475-484 ◽  
Author(s):  
Jin LEE ◽  
Andrew SHIRK ◽  
John F. ORAM ◽  
Sum P. LEE ◽  
Rahul KUVER
Keyword(s):  
Epithelial Cells ◽  
Gall Bladder ◽  
Cholesterol Efflux ◽  
Hormone Receptors ◽  
Cholesterol Absorption ◽  
Porous Membrane ◽  
Confocal Immunofluorescence Microscopy ◽  
High Concentrations ◽  
Model Bile ◽  
Efflux Pathway

Gall-bladder epithelial cells (GBEC) are exposed to high concentrations of cholesterol in bile. Whereas cholesterol absorption by GBEC is established, the fate of this absorbed cholesterol is not known. The aim of this study was to determine whether ABCA1 (ATP-binding cassette transporter A1) mediates cholesterol efflux in GBEC. Polarized canine GBEC were cultured on porous membrane filters allowing separate access to apical (AP) and basolateral (BL) compartments. After AP loading of cells with model bile and [14C]cholesterol, cholesterol efflux was measured. Cholesterol loading together with 8-bromo-cAMP treatment, which increased ABCA1 expression, led to a significant increase in cholesterol efflux with apolipoprotein A-I (apoA-I) as the acceptor. Cholesterol efflux was observed predominantly into the BL compartment. Similar results were found for phospholipid efflux. Confocal immunofluorescence microscopy showed a predominantly BL ABCA1 localization. Interestingly, apoA-I added to either the AP or the BL compartments elicited BL lipid efflux with cAMP treatment. No paracellular or transcellular passage of 125I-apoA-I occurred. Ligands for the nuclear hormone receptors liver X receptor α (LXRα) and retinoid X receptor (RXR) elicited AP and BL cholesterol efflux, suggesting the involvement of both ABCA1- and non-ABCA1-mediated pathways. In summary, BL cholesterol/phospholipid efflux consistent with an ABCA1-mediated mechanism occurs in GBEC. This efflux pathway is stimulated by cAMP and by LXRα/RXR ligands, and in the case of the cAMP pathway appears to involve a role for biliary apoA-I.

Female sex steroid induced gallbladder epithelium changes and gallstone deposits in female hamsters: TEM and SEM aspects

1993 ◽  
Vol 51 ◽  
pp. 354-355
Author(s):  
S. Karkare ◽  
J. Gilloteaux ◽  
T. R. Kelly
Keyword(s):  
Hormone Receptors ◽  
Corn Oil ◽  
Estrogen Therapy ◽  
Gallstone Formation ◽  
The United States ◽  
Sex Steroid ◽  
Estradiol Valerate ◽  
Surface Epithelium ◽  
Female Sex ◽  
Purina Chow

Approximately 1 million people in the United States alone develop gallstones each year. The incidence is higher in women than in men and the ratio being 4 ≥ 1. A correlation has also been suggested between oral contraceptives and cholelithiasis. In addition, postmenopausal or cancer estrogen therapy has been reported to be a factor responsible for gallstone formation. Female sex hormone receptors have been detected not only in the gallbladder musculature, but also in its epithelium. As a follow up to experiments effectuated in the male and the ovariectomized Syrian hamster, this report shows that, a combination of a low cholesterol diet with female sex steroid treatment contributes to the formation of gallstone-like deposits, while modifying the surface epithelium morphology. Syrian hamsters (F1B strain, BioBreeders, Watertown MA) were housed under 12h light: 12 h dark cycle, at 20 °C, fed Purina chow and water ad libitum. Several duration/treatment groups were studied, but this report will focus on data obtained with the group injected weekly with estradiol valerate (E weekly, s.c. 8-10 μg/100 g.b.w., in corn oil) and with i.m. medroxyprogesterone acetate (DepoProvera Upjohn Co., Kalamazoo, MI; 8-10 mg/100 g.b.w.) for a 3-month period. Other parameters (blood and bile) were also studied but not reported here.

11 beta-hydroxysteroid dehydrogenase and corticosteroid hormone receptors in the rat colon

1993 ◽  
Vol 264 (6) ◽  
pp. E951-E957 ◽  
Author(s):  
C. B. Whorwood ◽  
P. C. Barber ◽  
J. Gregory ◽  
M. C. Sheppard ◽  
P. M. Stewart
Keyword(s):  
Epithelial Cells ◽  
Lamina Propria ◽  
Hormone Receptors ◽  
Rat Kidney ◽  
Distal Colon ◽  
Hydroxysteroid Dehydrogenase ◽  
Neuroendocrine Cells ◽  
Rat Colon ◽  
Mrna Levels

In the rat kidney 11 beta-hydroxysteroid dehydrogenase (11 beta-HSD) maintains normal in vivo specificity for mineralocorticoid receptor (MR) by converting the active steroid corticosterone to inactive 11-dehydrocorticosterone, leaving aldosterone to occupy the MR. Clinical observations support the hypothesis that 11 beta-HSD also protects the distal colonic MR from glucocorticoid excess. We have measured 11 beta-HSD mRNA and activity along the rat colon and have analyzed the distribution of 11 beta-HSD, MR, and glucocorticoid receptor (GR) mRNA within rat distal colon using in situ hybridization. Levels of 11 beta-HSD mRNA (1.7 and 3.4 kb) and activity were higher in distal vs. proximal colon, paralleling reported MR mRNA levels. Within the distal colon mucosa both 11 beta-HSD immunoreactivity and mRNA was observed in cells in the lamina propria but not in epithelial cells. MR mRNA was present in surface epithelial cells, but was also colocalized with the same 11 beta-HSD-expressing cells in the lamina propria. In contrast GR mRNA was more uniformly distributed. The localization of MR mRNA to nonepithelial cells in the lamina propria, possibly neuroendocrine cells, suggests that mineralocorticoid-regulated sodium transport across colonic epithelial cells may also involve a paracrine mechanism. As with the kidney, exposure of active mineralocorticoid to the MR in these cells in the lamina propria is dictated by 11 beta-HSD in an autocrine fashion.

Immunolocalization of sex steroid hormone receptors in the canine uterine tube and their relation to sex steroid hormone levels

2002 ◽  
Vol 14 (4) ◽  
pp. 241 ◽  
Author(s):  
Hilde Vermeirsch ◽  
Wim Van Den Broeck ◽  
Mark Coryn ◽  
Paul Simoens
Keyword(s):  
Epithelial Cells ◽  
Estrous Cycle ◽  
Stromal Cells ◽  
Hormone Receptors ◽  
Steroid Hormone ◽  
Steroid Hormone Receptors ◽  
Sex Steroid ◽  
Nuclear Staining ◽  
Sex Steroid Hormone ◽  
Uterine Tube

The aim of this immunohistochemical study was to describe the cellular distribution of the estrogen receptor-α (ERα), progesterone receptor (PR) and androgen receptor (AR) in canine uterine tubes. Samples of uterine tubes were taken from dogs in different stages of the estrous cycle, and dogs that were pregnant or had just delivered. Nuclear staining for sex steroid hormone receptors was observed in the surface epithelium, stromal cells and smooth muscle cells of the muscular layer. Only slight differences in staining pattern were observed between the ampulla and fimbriae. The staining for ERα and PR showed changes throughout the estrous cycle. Some of these changes were related to changing concentrations of sex steroid hormones. High staining scores for ERα and PR were found during proestrus and low scores during early metestrus. The staining for AR showed only minor cyclic changes. However, during proestrus and estrus, cytoplasmic staining for AR was observed in differentiated secretory epithelial cells, when nuclear staining in these cells was nearly absent. For the three hormone receptors, stromal cells generally stained with a higher intensity than epithelial cells. It is likely that many steroid hormone actions on the epithelium are mediated through stromal cells. During pregnancy, rather high staining scores were found for ERα and AR in the uterine tube. This is in contrast to observations in the canine pregnant uterus.

scholarly journals Regulation of functional steroid receptors and ligand-induced responses in telomerase-immortalized human endometrial epithelial cells

2005 ◽  
Vol 34 (2) ◽  
pp. 517-534 ◽  
Author(s):  
S Hombach-Klonisch ◽  
A Kehlen ◽  
P A Fowler ◽  
B Huppertz ◽  
J F Jugert ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Estrogen Receptor Alpha ◽  
Hormone Receptors ◽  
Steroid Receptors ◽  
Steroid Hormone ◽  
Three Dimensional ◽  
Steroid Hormone Receptors ◽  
Endogenous Estrogen ◽  
Endometrial Epithelial Cells

Information on the regulation of steroid hormone receptors and their distinct functions within the human endometrial epithelium is largely unavailable. We have immortalized human primary endometrial epithelial cells (EECs) isolated from a normal proliferative phase endometrium by stably transfecting the catalytic subunit (hTERT) of the human telomerase complex and cultured these hTERT-EECs now for over 350 population doublings. Active hTERT was detected in hTERT-EECs employing the telomerase repeat amplification assay protocol. hTERT-EECs revealed a polarized, non-invasive epithelial phenotype with apical microvilli and production of a basal lamina when grown on a three-dimensional collagen–fibroblast lattice. Employing atomic force microscopy, living hTERT-EECs were shown to produce extracellular matrix (ECM) components and ECM secretion was modified by estrogen and progesterone (P4). hTERT-EECs expressed inducible and functional endogenous estrogen receptor-alpha (ER-alpha) as demonstrated by estrogen response element reporter assays and induction of P4 receptor (PR). P4 treatment down-regulated PR expression, induced MUC-1 gene activity and resulted in increased ER-beta transcriptional activity. Gene activities of cytokines and their receptors interleukin (IL)-6, leukemia inhibitory factor (LIF), IL-11 and IL-6 receptor (IL6-R), LIF receptor and gp130 relevant to implantation revealed a 17 beta-estradiol (E2)-mediated up-regulation of IL-6 and an E2- and P4-mediated up-regulation of IL6-R in hTERT-EECs. Thus, hTERT-EECs may be regarded as a novel in vitro model to investigate the role of human EECs in steroid hormone-dependent normal physiology and pathologies, including implantation failure, endometriosis and endometrial cancer.

Abstract 616: Interleukin 22 Downregulates ABCG1 and Impairs Cholesterol Efflux in Macrophages

2014 ◽  
Vol 34 (suppl_1) ◽  
Author(s):  
Marion Hofmann Bowman ◽  
Bijoy Chellan ◽  
Ling Yan ◽  
Timothy Sonntag ◽  
Catherine Reardon
Keyword(s):  
Protein Expression ◽  
Barrier Function ◽  
Cholesterol Efflux ◽  
Peritoneal Macrophages ◽  
Mouse Serum ◽  
Epithelial Barrier ◽  
Dependent Manner ◽  
Epithelial Barrier Function ◽  
Cholesterol Uptake ◽  
Mrna And Protein Expression

IL22 belongs to the IL10 cytokine family and is expressed by T helper cells. IL22 functions on epithelial cells and has been shown to improve epithelial barrier function in inflammatory bowel disease, asthma, and psoriasis; autoimmune diseases associated with elevated serum IL22. Patients with psoriasis have increased coronary artery disease and it was previously shown that macrophages from patients with psoriasis have impaired cholesterol efflux. The function of IL-22 on macrophage cholesterol metabolism is not known. Methods: ABCA1, ABCG1 and CD36 mRNA and protein expression, cholesterol uptake and efflux were studied in murine macrophages and human THP-1 macrophages. C57BL6/J mice with transgenic expression of hS100A12 and hS100A8/9 in myeloid cells were generated by using a bacterial artificial chromosome (hBAC/S100 mice). hBAC/S100 and WT littermate mice were breed into mice lacking the receptor for advanced glycation endproducts, RAGE. Results: Peritoneal macrophages from hBAC/S100 mice have reduced ABCG1 mRNA and protein expression, increased cholesterol uptake, and reduced cholesterol efflux compared to WT. This was abolished in hBAC/S100 mice lacking RAGE, the receptor for S100/calgranulin. Recombinant S100A12 or S100A8 protein (2.5 μg/ml) had no effect on ABCG1 expression in WT peritoneal macrophages or human THP-1 cells, suggesting other systemic intermediary products in hBAC/S100 mice. Serum IL22 and mRNA in splenic T cells were significantly increased in hBAC/S100 mice, and this was abolished in hBAC/S100 mice lacking RAGE. Moreover, r S100A12 increased IL22 mRNA by 2-fold in cultured human THP-1. Importantly, THP-1 macrophages treated with r IL22 (100 ng/ml) had reduced expression of ABCG1 and impaired cholesterol efflux to mouse serum, but not to Apoa1. Up regulation of ABCG1 and ABCA1 in response to LXR agonist TO901317 in THP-1 cells abolished the detrimental effects of IL22 on cholesterol efflux. Conclusion: S100/calgranulin induces IL22 in a RAGE dependent manner. IL22 down regulates ABCG1 and impairs cholesterol efflux in macrophages. This raises the hypothesis that IL22-mediated down regulation of cellular cholesterol efflux may be linked to improved epithelial barrier function, but may also augment atherosclerosis.

Basolateral secretion of kappa light chain in the polarised epithelial cell line, Caco-2

1989 ◽  
Vol 94 (2) ◽  
pp. 327-332
Author(s):  
E.J. Hughson ◽  
D.F. Cutler ◽  
C.R. Hopkins
Keyword(s):  
Epithelial Cell ◽  
Epithelial Cells ◽  
Cell Line ◽  
Light Chain ◽  
Intracellular Trafficking ◽  
Epithelial Cell Line ◽  
Kappa Light Chain ◽  
Immunoglobulin Kappa ◽  
Selective Delivery ◽  
Secretory Products

The immunoglobulin kappa light chain is constitutively secreted in non-polarised cells. It is therefore unlikely to display any of the signals thought to be required for the selective delivery of proteins to the apical or basolateral borders of polarised epithelial cells. We have transfected the gene for the kappa light chain into a polarised epithelial cell line (Caco-2) and shown that it is secreted predominantly from the basolateral surface. Metabolically labelled endogenous secretory products show the same polarity and we conclude, therefore, that in Caco-2 cells there is a major intracellular trafficking route to the basolateral border that requires no sorting signal.

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