scholarly journals p23 Modulates Aryl Hydrocarbon Receptor Protein Levels in Normal Cell Lines

2018 ◽  
Vol 32 (S1) ◽  
Author(s):  
Jinyun Chen ◽  
Poonam Yakkundi ◽  
William K. Chan
Keyword(s):  
Aryl Hydrocarbon Receptor ◽  
Cell Lines ◽  
Normal Cell ◽  
Receptor Protein ◽  
Protein Levels ◽  
Aryl Hydrocarbon

scholarly journals Loss of hepatic aryl hydrocarbon receptor protein in adrenalectomized rats does not involve altered levels of the receptor’s cytoplasmic chaperones

2013 ◽  
Vol 91 (12) ◽  
pp. 1154-1157 ◽  
Author(s):  
Chunja Lee ◽  
Anne K. Mullen Grey ◽  
David S. Riddick
Keyword(s):  
Aryl Hydrocarbon Receptor ◽  
Environmental Pollutants ◽  
Receptor Protein ◽  
Interacting Protein ◽  
Cytochrome P450 1B1 ◽  
Protein Levels ◽  
Aryl Hydrocarbon ◽  
Conditional Deletion ◽  
Toxic Responses ◽  
Adrenalectomized Rats

The aryl hydrocarbon receptor (AHR) plays physiological roles and mediates adaptive and toxic responses to environmental pollutants. Adrenalectomized rats display decreased hepatic AHR protein levels, with no change in mRNA, and selectively impaired induction of cytochrome P450 1B1. This is similar to reported phenotypes for mice with hepatocyte-specific conditional deletion of AHR-interacting protein (AIP), a chaperone protein of the cytoplasmic AHR complex. In this study, we demonstrated that adrenalectomy (ADX) and acute dexamethasone (DEX) treatment do not alter hepatic AIP mRNA or protein levels. Also, hepatic protein levels of the 90 kDa heat shock protein and p23 were not altered by ADX or acute DEX treatment. These results suggest that the loss of rat hepatic AHR protein following ADX cannot be explained by changes in the levels of the receptor’s cytoplasmic chaperone proteins.

scholarly journals Expression, Localization, and Activity of the Aryl Hydrocarbon Receptor in the Human Placenta

2018 ◽  
Vol 19 (12) ◽  
pp. 3762 ◽  
Author(s):  
Anaïs Wakx ◽  
Margaux Nedder ◽  
Céline Tomkiewicz-Raulet ◽  
Jessica Dalmasso ◽  
Audrey Chissey ◽  
...  
Keyword(s):  
Aryl Hydrocarbon Receptor ◽  
Human Placenta ◽  
Target Genes ◽  
Environmental Pollutants ◽  
Cell Fractionation ◽  
Protein Levels ◽  
Aryl Hydrocarbon ◽  
Epithelial Barriers ◽  
Expression And Activity

The human placenta is an organ between the blood of the mother and the fetus, which is essential for fetal development. It also plays a role as a selective barrier against environmental pollutants that may bypass epithelial barriers and reach the placenta, with implications for the outcome of pregnancy. The aryl hydrocarbon receptor (AhR) is one of the most important environmental-sensor transcription factors and mediates the metabolism of a wide variety of xenobiotics. Nevertheless, the identification of dietary and endogenous ligands of AhR suggest that it may also fulfil physiological functions with which pollutants may interfere. Placental AhR expression and activity is largely unknown. We established the cartography of AhR expression at transcript and protein levels, its cellular distribution, and its transcriptional activity toward the expression of its main target genes. We studied the profile of AhR expression and activity during different pregnancy periods, during trophoblasts differentiation in vitro, and in a trophoblast cell line. Using diverse methods, such as cell fractionation and immunofluorescence microscopy, we found a constitutive nuclear localization of AhR in every placental model, in the absence of any voluntarily-added exogenous activator. Our data suggest an intrinsic activation of AhR due to the presence of endogenous placental ligands.

scholarly journals Down-Regulation of p23 in Normal Lung Epithelial Cells Reduces Toxicities From Exposure to Benzo[a]pyrene and Cigarette Smoke Condensate via an Aryl Hydrocarbon Receptor-Dependent Mechanism

2018 ◽  
Vol 167 (1) ◽  
pp. 239-248 ◽  
Author(s):  
Jinyun Chen ◽  
Poonam Yakkundi ◽  
William K Chan
Keyword(s):  
Epithelial Cells ◽  
Aryl Hydrocarbon Receptor ◽  
Cigarette Smoke ◽  
Lung Epithelial Cells ◽  
Normal Lung ◽  
Cigarette Smoke Condensate ◽  
Down Regulation ◽  
Protein Levels ◽  
Aryl Hydrocarbon ◽  
Lung Epithelial

Abstract The aryl hydrocarbon receptor (AHR) is a ligand-activated signaling molecule which controls tumor growth and metastasis, T cell differentiation, and liver development. Expression levels of this receptor protein is sensitive to the cellular p23 protein levels in immortalized cancer cell lines. As little as 30% reduction of the p23 cellular content can suppress the AHR function. Here we reported that down-regulation of the p23 protein content in normal, untransformed human bronchial/tracheal epithelial cells to 48% of its content also suppresses the AHR protein levels to 54% of its content. This p23-mediated suppression of AHR is responsible for the suppression of (1) the ligand-dependent induction of the cyp1a1 gene transcription; (2) the benzo[a]pyrene- or cigarette smoke condensate-induced CYP1A1 enzyme activity, and (3) the benzo[a]pyrene and cigarette smoke condensate-mediated production of reactive oxygen species. Reduction of the p23 content does not alter expression of oxidative stress genes and production of PGE2. Down regulation of p23 suppresses the AHR protein levels in two other untransformed cell types, namely human breast MCF-10A and mouse immune regulatory Tr1 cells. Collectively, down-regulation of p23 suppresses the AHR protein levels in normal and untransformed cells and can in principle protect our lung epithelial cells from AHR-dependent oxidative damage caused by exposure to agents from environment and cigarette smoking.

scholarly journals Aryl Hydrocarbon Receptor Modulates the Expression of TNF-α and IL-8 in Human Sebocytes via the MyD88-p65NF-κB/p38MAPK Signaling Pathways

2018 ◽  
Vol 11 (1) ◽  
pp. 41-51 ◽  
Author(s):  
Xiao-Xiao Hou ◽  
Guangjie Chen ◽  
Amir M. Hossini ◽  
Tingting Hu ◽  
Lanqi Wang ◽  
...  
Keyword(s):  
Aryl Hydrocarbon Receptor ◽  
Physiological Stress ◽  
Acne Vulgaris ◽  
Receptor Protein ◽  
Inflammatory Factors ◽  
Induced Expression ◽  
Aryl Hydrocarbon ◽  
Tnf Α ◽  
P38mapk Signaling ◽  
Myeloid Differentiation Factor

Activation of Toll-like receptor (TLR)-2 and subsequent inflammatory response contribute to lesion development in acne vulgaris. A cross-talk between aryl hydrocarbon receptor (AhR), a cytosolic receptor protein that responds to environmental and physiological stress, and TLRs has recently been reported. In this study, we explored the possible role of AhR in the effects induced on cultured human SZ95 sebocytes by peptidoglycan (PGN), a classic TLR2 agonist. PGN-induced secretion of inflammatory factors TNF-α and IL-8 in human SZ95 sebocytes was suppressed after knockdown of AhR and pretreatment with the AhR antagonist CH223191. In addition, the AhR agonist 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) enhanced TNF-α and IL-8 secretion in PGN-pretreated sebocytes. Furthermore, PGN-induced expression of myeloid differentiation factor 88 (MyD88), phospho-p38MAPK (p-p38MAPK), and p-p65NF-κB was strengthened by TCDD and repressed by CH223191. AhR inhibition by transfecting shRNA blocked the ability of PGN to stimulate phosphorylation of p38MAPK and p65NF-κB in SZ95 sebocytes. Overall, these data demonstrate that AhR is able to modulate PGN-induced expression of TNF-α and IL-8 in human SZ95 sebocytes involving the MyD88-p65NF-κB/p38MAPK signaling pathway, which probably indicates a new mechanism in TLR2-mediated acne.

scholarly journals Expression Changes and Impact of the Extracellular Matrix on Etoposide Resistant Human Retinoblastoma Cell Lines

2020 ◽  
Vol 21 (12) ◽  
pp. 4322 ◽  
Author(s):  
Jacqueline Reinhard ◽  
Natalie Wagner ◽  
Miriam M. Krämer ◽  
Marvin Jarocki ◽  
Stephanie C. Joachim ◽  
...  
Keyword(s):  
Extracellular Matrix ◽  
Mrna Expression ◽  
Cell Lines ◽  
Cluster Formation ◽  
Collagen Iv ◽  
Tissue Inhibitor Of Metalloproteinase ◽  
Receptor Protein ◽  
Tenascin C ◽  
Chemotherapy Drugs ◽  
Protein Levels

Retinoblastoma (RB) represents the most common malignant childhood eye tumor worldwide. Several studies indicate that the extracellular matrix (ECM) plays a crucial role in tumor growth and metastasis. Moreover, recent studies indicate that the ECM composition might influence the development of resistance to chemotherapy drugs. The objective of this study was to evaluate possible expression differences in the ECM compartment of the parental human cell lines WERI-RB1 (retinoblastoma 1) and Y79 and their Etoposide resistant subclones via polymerase chain reaction (PCR). Western blot analyses were performed to analyze protein levels. To explore the influence of ECM molecules on RB cell proliferation, death, and cluster formation, WERI-RB1 and resistant WERI-ETOR cells were cultivated on Fibronectin, Laminin, Tenascin-C, and Collagen IV and analyzed via time-lapse video microscopy as well as immunocytochemistry. We revealed a significantly reduced mRNA expression of the proteoglycans Brevican, Neurocan, and Versican in resistant WERI-ETOR compared to sensitive WERI-RB1 cells. Also, for the glycoproteins α1-Laminin, Fibronectin, Tenascin-C, and Tenascin-R as well as Collagen IV, reduced expression levels were observed in WERI-ETOR. Furthermore, a downregulation was detected for the matrix metalloproteinases MMP2, MMP7, MMP9, the tissue-inhibitor of metalloproteinase TIMP2, the Integrin receptor subunits ITGA4, ITGA5 and ITGB1, and all receptor protein tyrosine phosphatase β/ζ isoforms. Downregulation of Brevican, Collagen IV, Tenascin-R, MMP2, TIMP2, and ITGA5 was also verified in Etoposide resistant Y79 cells compared to sensitive ones. Protein levels of Tenascin-C and MMP-2 were comparable in both WERI cell lines. Interestingly, Fibronectin displayed an apoptosis-inducing effect on WERI-RB1 cells, whereas an anti-apoptotic influence was observed for Tenascin-C. Conversely, proliferation of WERI-ETOR cells was enhanced on Tenascin-C, while an anti-proliferative effect was observed on Fibronectin. In WERI-ETOR, cluster formation was decreased on the substrates Collagen IV, Fibronectin, and Tenascin-C. Collectively, we noted a different ECM mRNA expression and behavior of Etoposide resistant compared to sensitive RB cells. These findings may indicate a key role of ECM components in chemotherapy resistance formation of RB.

scholarly journals Study of the 16 EU-JECFA PAHs interaction with the aryl hydrocarbon receptor (AhR) using rat and human reporter cell lines

2007 ◽  
Vol 172 ◽  
pp. S37-S38
Author(s):  
Catherine Brasseur ◽  
Danielle Melens ◽  
Marc Muller ◽  
Guy Maghuin-Rogister ◽  
Marie-Louise Scippo
Keyword(s):  
Aryl Hydrocarbon Receptor ◽  
Cell Lines ◽  
Reporter Cell ◽  
Aryl Hydrocarbon

scholarly journals Selective Autophagy Maintains the Aryl Hydrocarbon Receptor Levels in HeLa Cells: A Mechanism That Is Dependent on the p23 Co-Chaperone

2020 ◽  
Vol 21 (10) ◽  
pp. 3449
Author(s):  
Yujie Yang ◽  
William K. Chan
Keyword(s):  
Aryl Hydrocarbon Receptor ◽  
Hela Cells ◽  
Stem Cell Differentiation ◽  
26S Proteasome ◽  
Chemical Agent ◽  
Physical Interaction ◽  
Hematopoietic Stem ◽  
Selective Autophagy ◽  
Protein Levels ◽  
Aryl Hydrocarbon

The aryl hydrocarbon receptor (AHR) is an environmental sensing molecule which impacts diverse cellular functions such as immune responses, cell growth, respiratory function, and hematopoietic stem cell differentiation. It is widely accepted that the degradation of AHR by 26S proteasome occurs after ligand activation. Recently, we discovered that HeLa cells can modulate the AHR levels via protein degradation without exogenous treatment of a ligand, and this degradation is particularly apparent when the p23 content is down-regulated. Inhibition of autophagy by a chemical agent (such as chloroquine, bafilomycin A1, or 3-methyladenine) increases the AHR protein levels in HeLa cells whereas activation of autophagy by short-term nutrition deprivation reduces its levels. Treatment of chloroquine retards the degradation of AHR and triggers physical interaction between AHR and LC3B. Knockdown of LC3B suppresses the chloroquine-mediated increase of AHR. Down-regulation of p23 promotes AHR degradation via autophagy with no change of the autophagy-related gene expression. Although most data in this study were derived from HeLa cells, human lung (A549), liver (Hep3B), and breast (T-47D and MDA-MB-468) cells also exhibit AHR levels sensitive to chloroquine treatment and AHR–p62/LC3 interactions. Here we provide evidence supporting that AHR undergoes the p62/LC3-mediated selective autophagy in HeLa cells.

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