scholarly journals Inhibiting SARS-CoV-2 infection in vitro by suppressing its receptor, angiotensin-converting enzyme 2, via aryl-hydrocarbon receptor signal

2021 ◽  
Author(s):  
Keiji Tanimoto ◽  
Kiichi Hirota ◽  
Takahiro Fukazawa ◽  
Yoshiyuki Matsuo ◽  
Toshihito Nomura ◽  
...  
Keyword(s):  
Aryl Hydrocarbon Receptor ◽  
Cigarette Smoke ◽  
Mammalian Cells ◽  
Molecular Mechanisms ◽  
Dependent Manner ◽  
Angiotensin Converting Enzyme 2 ◽  
Aryl Hydrocarbon ◽  
Internalization Mechanism ◽  
Receptor Signal

AbstractSince understanding molecular mechanisms of SARS-CoV-2 infection is extremely important for developing effective therapies against COVID-19, we focused on the internalization mechanism of SARS-CoV-2 via ACE2. Although cigarette smoke is generally believed to be harmful to the pathogenesis of COVID-19, cigarette smoke extract (CSE) treatments were surprisingly found to suppress the expression of ACE2 in HepG2 cells. We thus tried to clarify the mechanism of CSE effects on expression of ACE2 in mammalian cells. Because RNA-seq analysis suggested that suppressive effects on ACE2 might be inversely correlated with induction of the genes regulated by aryl hydrocarbon receptor (AHR), the AHR agonists 6-formylindolo(3,2-b)carbazole (FICZ) and omeprazole (OMP) were tested to assess whether those treatments affected ACE2 expression. Both FICZ and OMP clearly suppressed ACE2 expression in a dose-dependent manner along with inducing CYP1A1. Knock-down experiments indicated a reduction of ACE2 by FICZ treatment in an AHR-dependent manner. Finally, treatments of AHR agonists inhibited SARS-CoV-2 infection into Vero E6 cells as determined with immunoblotting analyses detecting SARS-CoV-2 specific nucleocapsid protein. We here demonstrate that treatment with AHR agonists, including CSE, FICZ, and OMP, decreases expression of ACE2 via AHR activation, resulting in suppression of SARS-CoV-2 infection in mammalian cells.

scholarly journals Inhibiting SARS-CoV-2 infection in vitro by suppressing its receptor, angiotensin-converting enzyme 2, via aryl-hydrocarbon receptor signal

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Keiji Tanimoto ◽  
Kiichi Hirota ◽  
Takahiro Fukazawa ◽  
Yoshiyuki Matsuo ◽  
Toshihito Nomura ◽  
...  
Keyword(s):  
Aryl Hydrocarbon Receptor ◽  
Cigarette Smoke ◽  
Mammalian Cells ◽  
Molecular Mechanisms ◽  
Dependent Manner ◽  
Angiotensin Converting Enzyme 2 ◽  
Aryl Hydrocarbon ◽  
Internalization Mechanism ◽  
Receptor Signal

AbstractSince understanding molecular mechanisms of SARS-CoV-2 infection is extremely important for developing effective therapies against COVID-19, we focused on the internalization mechanism of SARS-CoV-2 via ACE2. Although cigarette smoke is generally believed to be harmful to the pathogenesis of COVID-19, cigarette smoke extract (CSE) treatments were surprisingly found to suppress the expression of ACE2 in HepG2 cells. We thus tried to clarify the mechanism of CSE effects on expression of ACE2 in mammalian cells. Because RNA-seq analysis suggested that suppressive effects on ACE2 might be inversely correlated with induction of the genes regulated by aryl hydrocarbon receptor (AHR), the AHR agonists 6-formylindolo(3,2-b)carbazole (FICZ) and omeprazole (OMP) were tested to assess whether those treatments affected ACE2 expression. Both FICZ and OMP clearly suppressed ACE2 expression in a dose-dependent manner along with inducing CYP1A1. Knock-down experiments indicated a reduction of ACE2 by FICZ treatment in an AHR-dependent manner. Finally, treatments of AHR agonists inhibited SARS-CoV-2 infection into Vero E6 cells as determined with immunoblotting analyses detecting SARS-CoV-2 specific nucleocapsid protein. We here demonstrate that treatment with AHR agonists, including FICZ, and OMP, decreases expression of ACE2 via AHR activation, resulting in suppression of SARS-CoV-2 infection in mammalian cells.

scholarly journals Environmental Benzopyrene Attenuates Stemness of Placenta-Derived Mesenchymal Stem Cells via Aryl Hydrocarbon Receptor

2019 ◽  
Vol 2019 ◽  
pp. 1-12 ◽  
Author(s):  
June Seok Heo ◽  
Ja-Yun Lim ◽  
Sangshin Pyo ◽  
Dae Wui Yoon ◽  
Dongsook Lee ◽  
...  
Keyword(s):  
Stem Cells ◽  
Mesenchymal Stem Cells ◽  
Aryl Hydrocarbon Receptor ◽  
Molecular Mechanisms ◽  
Cell Activity ◽  
Bone Diseases ◽  
Purine Derivative ◽  
Aryl Hydrocarbon ◽  
Polycyclic Aromatic

The toxic effects of particulate matter have been linked to polycyclic aromatic hydrocarbons (PAHs) such as benzopyrene. PAHs are potent inducers of the aryl hydrocarbon receptor (AhR), which is an expressed nuclear receptor that senses environmental stimuli and modulates gene expression. Even though several studies have shown that the benzopyrene (BP) of chemical pollutants significantly impaired stem cell activity, the exact molecular mechanisms were not clearly elucidated. In the present study, we aimed to investigate the effects of BP on placenta-derived mesenchymal stem cells (PD-MSCs) in vitro. We found that the AhR in PD-MSCs was expressed under the treatment of BP, and its activation markedly disrupted osteogenic differentiation through the alteration of stemness activity of PD-MSCs. Moreover, BP treatment significantly reduced the proliferation activity of PD-MSCs and expression of pluripotent markers through the induction of AhR. Treatment with StemRegenin 1 (SR1), a purine derivative that antagonizes the AhR, effectively prevented BP-induced reduction of the proliferation and differentiation activity of PD-MSCs. In this study, we found that BP treatment in PD-MSCs markedly obstructs PD-MSC stemness through AhR signaling. Noteworthy, SR1-mediated MSC application will contribute to new perspectives on MSC-based therapies for air pollution-related bone diseases.

scholarly journals Streptococcus gallolyticus Increases Expression and Activity of Aryl Hydrocarbon Receptor-Dependent CYP1 Biotransformation Capacity in Colorectal Epithelial Cells

2021 ◽  
Vol 11 ◽  
Author(s):  
Rahwa Taddese ◽  
Rian Roelofs ◽  
Derk Draper ◽  
Xinqun Wu ◽  
Shaoguang Wu ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Aryl Hydrocarbon Receptor ◽  
Specific Inhibitor ◽  
Intestinal Bacteria ◽  
Opportunistic Pathogen ◽  
Dependent Manner ◽  
Aryl Hydrocarbon ◽  
Streptococcus Gallolyticus

ObjectiveThe opportunistic pathogen Streptococcus gallolyticus is one of the few intestinal bacteria that has been consistently linked to colorectal cancer (CRC). This study aimed to identify novel S. gallolyticus-induced pathways in colon epithelial cells that could further explain how S. gallolyticus contributes to CRC development.Design and ResultsTranscription profiling of in vitro cultured CRC cells that were exposed to S. gallolyticus revealed the specific induction of oxidoreductase pathways. Most prominently, CYP1A and ALDH1 genes that encode phase I biotransformation enzymes were responsible for the detoxification or bio-activation of toxic compounds. A common feature is that these enzymes are induced through the Aryl hydrocarbon receptor (AhR). Using the specific inhibitor CH223191, we showed that the induction of CYP1A was dependent on the AhR both in vitro using multiple CRC cell lines as in vivo using wild-type C57bl6 mice colonized with S. gallolyticus. Furthermore, we showed that CYP1 could also be induced by other intestinal bacteria and that a yet unidentified diffusible factor from the S. galloltyicus secretome (SGS) induces CYP1A enzyme activity in an AhR-dependent manner. Importantly, priming CRC cells with SGS increased the DNA damaging effect of the polycyclic aromatic hydrocarbon 3-methylcholanthrene.ConclusionThis study shows that gut bacteria have the potential to modulate the expression of biotransformation pathways in colonic epithelial cells in an AhR-dependent manner. This offers a novel theory on the contribution of intestinal bacteria to the etiology of CRC by modifying the capacity of intestinal epithelial or (pre-)cancerous cells to (de)toxify dietary components, which could alter intestinal susceptibility to DNA damaging events.

scholarly journals Aryl hydrocarbon receptor signaling pathway plays important roles in the proliferative and metabolic properties of bone marrow mesenchymal stromal cells

2021 ◽  
Author(s):  
Yan Jia ◽  
Youshan Zhao ◽  
Zheng Zhang ◽  
Lei Shi ◽  
Ying Fang ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Aryl Hydrocarbon Receptor ◽  
Mesenchymal Stromal Cells ◽  
Stromal Cells ◽  
Molecular Mechanisms ◽  
Therapeutic Potential ◽  
Aryl Hydrocarbon ◽  
Receptor Signaling Pathway ◽  
Metabolic Properties

Abstract Bone marrow mesenchymal stromal cells (BMMSCs) are widely sourced and easily amplified in vitro; thus, they have a great potential in the treatment of hemopathies. Recent findings suggested that BMMSCs express the aryl hydrocarbon receptor (AHR). However, few studies have reported on the regulation of proliferative behaviors and metabolism by AHR in BMMSCs. In the present study, we found that activating AHR reduced the proliferation of BMMSCs and enhanced their mitochondrial function, whereas inhibiting AHR exerted the opposite effects. This study may provide the basis for further unveiling the molecular mechanisms and therapeutic potential of AHR in BMMSCs.

scholarly journals Inhibition of dioxin effects on bone formation in vitro by a newly described aryl hydrocarbon receptor antagonist, resveratrol

2000 ◽  
Vol 167 (1) ◽  
pp. 183-195 ◽  
Author(s):  
SU Singh ◽  
RF Casper ◽  
PC Fritz ◽  
B Sukhu ◽  
B Ganss ◽  
...  
Keyword(s):  
Periodontal Disease ◽  
Aryl Hydrocarbon Receptor ◽  
Cigarette Smoke ◽  
Bone Cell ◽  
Nodule Formation ◽  
Antifungal Compound ◽  
Type I ◽  
Aryl Hydrocarbon

Aryl hydrocarbon receptor (AhR) ligands are environmental contaminants found in cigarette smoke and other sources of air pollution. The prototypical compound is TCDD (2,3,7, 8-tetrachlorodibenzo-p-dioxin), also known as dioxin. There is an increasing body of knowledge linking cigarette smoking to osteoporosis and periodontal disease, but the direct effects of smoke-associated aryl hydrocarbons on bone are not well understood. Through the use of resveratrol (3,5,4'-trihydroxystilbene), a plant antifungal compound that we have recently demonstrated to be a pure AhR antagonist, we have investigated the effects of TCDD on osteogenesis. It was postulated that TCDD would inhibit osteogenesis in bone-forming cultures and that this inhibition would be antagonized by resveratrol. We employed the chicken periosteal osteogenesis (CPO) model, which has been shown to form bone in vitro in a pattern morphologically and biochemically similar to that seen in vivo, as well as a rat stromal cell bone nodule formation model. In the CPO model, alkaline phosphatase (AP) activity was reduced by up to 50% (P<0.01 vs control) in the presence of 10(-9) M TCDD and these effects were reversed by 10(-6) M resveratrol (P<0.05 vs TCDD alone). TCDD-mediated inhibition of osteogenesis was restricted primarily to the osteoblastic differentiation phase (days 0-2) as later addition did not appear to have any effects. Message levels for important bone-associated proteins (in the CPO model) such as collagen type I, osteopontin, bone sialoprotein and AP were inhibited by TCDD, an effect that was antagonized by resveratrol. Similar findings were obtained using the rat stromal bone cell line. TCDD (at concentrations as low as 10(-10)M) caused an approximately 33% reduction in AP activity, which was abrogated by 3. 5x10(-7) M resveratrol. TCDD also induced a marked reduction in mineralization ( approximately 75%) which was completely antagonized by resveratrol. These data suggest that AhR ligands inhibit osteogenesis probably through inhibition of osteodifferentiation and that this effect can be antagonized by resveratrol. Since high levels of AhR ligands are found in cigarette smoke, and further since smoking is an important risk factor in both osteoporosis and periodontal disease, it may be postulated that AhR ligands are the component of cigarette smoke linking smoking to osteoporosis and periodontal disease. If so, resveratrol could prove to be a promising preventive or therapeutic agent for smoking-related bone loss.

scholarly journals AIP mutations impair AhR signaling in pituitary adenoma patients fibroblasts and in GH3 cells

2016 ◽  
Vol 23 (5) ◽  
pp. 433-443 ◽  
Author(s):  
Anne-Lise Lecoq ◽  
Say Viengchareun ◽  
Mirella Hage ◽  
Jérôme Bouligand ◽  
Jacques Young ◽  
...  
Keyword(s):  
Aryl Hydrocarbon Receptor ◽  
Protein Level ◽  
Pituitary Adenomas ◽  
Healthy Subjects ◽  
Molecular Mechanisms ◽  
Human Fibroblasts ◽  
Gh3 Cells ◽  
Dependent Manner ◽  
Aryl Hydrocarbon ◽  
The Impact

Germline mutations in the aryl hydrocarbon receptor-interacting protein (AIP) gene predispose humans to pituitary adenomas through unknown molecular mechanisms. The best-known interacting partner of AIP is the aryl hydrocarbon receptor (AhR), a transcription factor that mediates the effects of xenobiotics implicated in carcinogenesis. As 75% of AIP mutations disrupt the physical and/or functional interaction with AhR, we postulated that the tumorigenic potential of AIP mutations might result from altered AhR signaling. We evaluated the impact of AIP mutations on the AhR signaling pathway, first in fibroblasts from AIP-mutated patients with pituitary adenomas, by comparison with fibroblasts from healthy subjects, then in transfected pituitary GH3 cells. The AIP protein level in mutated fibroblasts was about half of that in cells from healthy subjects, but AhR expression was unaffected. Gene expression analyses showed significant modifications in the expression of the AhR target genes CYP1B1 and AHRR in AIP-mutated fibroblasts, both before and after stimulation with the endogenous AhR ligand kynurenine. Kynurenine increased Cyp1b1 expression to a greater extent in GH3 cells overexpressing wild type compared with cells expressing mutant AIP. Knockdown of endogenous Aip in these cells attenuated Cyp1b1 induction by the AhR ligand. Both mutant AIP expression and knockdown of endogenous Aip affected the kynurenine-dependent GH secretion of GH3 cells. This study of human fibroblasts bearing endogenous heterozygous AIP mutations and transfected pituitary GH3 cells shows that AIP mutations affect the AIP protein level and alter AhR transcriptional activity in a gene- and tissue-dependent manner.

Dual suppression of adipogenesis by cigarette smoke through activation of the aryl hydrocarbon receptor and induction of endoplasmic reticulum stress

2009 ◽  
Vol 296 (4) ◽  
pp. E721-E730 ◽  
Author(s):  
Tsuyoshi Shimada ◽  
Nobuhiko Hiramatsu ◽  
Kunihiro Hayakawa ◽  
Shuhei Takahashi ◽  
Ayumi Kasai ◽  
...  
Keyword(s):  
Endoplasmic Reticulum ◽  
Er Stress ◽  
Aryl Hydrocarbon Receptor ◽  
Cigarette Smoke ◽  
Molecular Mechanisms ◽  
Adipocyte Differentiation ◽  
Suppressive Effect ◽  
Dominant Negative ◽  
Dominant Negative Mutant ◽  
Aryl Hydrocarbon

Cigarette smoking decreases body weight, whereas molecular mechanisms underlying this phenomenon have not been elucidated. In this report, we investigated regulation of adipogenesis by cigarette smoke and involvement of aryl hydrocarbon receptor (AhR) and endoplasmic reticulum (ER) stress. We found that cigarette smoke extract (CSE) inhibited differentiation of preadipocytes into adipocytes dose dependently. It was associated with a decrease in lipid accumulation, blunted expression of adipocyte markers (adiponectin, PPAR-γ, and C/EBPα), and sustained expression of a preadipocyte marker MCP-1. CSE markedly induced activation of AhR, and AhR agonists (2,3,7,8-tetrachlorodibenzo- p-dioxin, benzo[ a]pyrene and 3-methylcholanthrene) reproduced the inhibitory effect of CSE on adipocyte differentiation. Furthermore, knockout of the AhR gene or blockade of AhR by a dominant-negative mutant attenuated the suppressive effects of CSE on adipocyte differentiation. We also found that CSE induced ER stress in preadipocytes, and ER stress inducers (thapsigargin, tunicamycin, and A23187) reproduced the suppressive effect of CSE on the differentiation of preadipocytes. Interestingly, AhR agonists did not cause ER stress, and ER stress inducers did not activate AhR. These results suggested that cigarette smoke has the potential to inhibit adipocyte differentiation via dual, independent mechanisms, i.e., through activation of the AhR pathway and induction of the unfolded protein response.

scholarly journals The Aryl Hydrocarbon Receptor (AhR) Mediates the Counter-Regulatory Effects of Pelargonidins in Models of Inflammation and Metabolic Dysfunctions

Nutrients ◽  
2019 ◽  
Vol 11 (8) ◽  
pp. 1820 ◽  
Author(s):  
Michele Biagioli ◽  
Adriana Carino ◽  
Chiara Fiorucci ◽  
Giannamaria Annunziato ◽  
Silvia Marchianò ◽  
...  
Keyword(s):  
Aryl Hydrocarbon Receptor ◽  
Natural Compound ◽  
Intestinal Inflammation ◽  
Body Weight Gain ◽  
Liver Steatosis ◽  
Signs And Symptoms ◽  
Dependent Manner ◽  
Aryl Hydrocarbon

Pelargonidins are anthocyanidins thought to be beneficial for the human health, although controversies exist over the doses needed and the unclear mechanism of action, along with poor systemic bioavailability. One putative target of pelargonidins is the aryl hydrocarbon receptor (AhR). A synthetic pelargonidin (Mt-P) was synthesized by the methylation of the pelargonidin (the natural compound indicated as P). Mt-P transactivated the AhR with an EC50 of 1.97 µM and was ~2-fold more potent than the natural compound. In vitro Mt-P attenuated pro-inflammatory activities of Raw264.7 macrophage cells in an AhR-dependent manner. In vivo, administration of the Mt-P in Balb/c mice resulted in a dose-dependent attenuation of signs and symptoms of colitis induced by TNBS. A dose of 5 mg/kg Mt-P, but not the natural compound P, reversed intestinal inflammation and increased expression of Tnf-α, Ifn-ƴ, and Il-6, while promoted the expansion of regulatory T cells and M2 macrophages. In C57BL/6J mice fed a high fat diet (HFD), Mt-P attenuated body weight gain, intestinal and liver inflammation, and ameliorated insulin sensitivity, while worsened liver steatosis by up-regulating the liver expression of Cd36 and Apo100b. These effects were abrogated by AhR gene ablation. Mt-P is a synthetic pelargonidin endowed with robust AhR agonist activity that exerts beneficial effects in murine models of inflammation and metabolic dysfunction.

scholarly journals Aryl Hydrocarbon Receptor Defect Attenuates Mitogen-Activated Signaling Through Leucine-Rich Repeats and Immunoglobulin-Like Domains 1 (LRIG1)-Dependent EGFR Degradation

2021 ◽  
Vol 22 (18) ◽  
pp. 9988
Author(s):  
Han-Lin Hsu ◽  
Hong-Kai Chen ◽  
Chi-Hao Tsai ◽  
Po-Lin Liao ◽  
Yen-Ju Chan ◽  
...  
Keyword(s):  
Aryl Hydrocarbon Receptor ◽  
Egf Receptor ◽  
Chronic Obstructive ◽  
Dependent Manner ◽  
Obstructive Pulmonary Disease ◽  
Aryl Hydrocarbon ◽  
Copd Patients ◽  
Leucine Rich Repeats

Aryl hydrocarbon receptor (AHR) genomic pathway has been well-characterized in a number of respiratory diseases. In addition, the cytoplasmic AHR protein may act as an adaptor of E3 ubiquitin ligase. In this study, the physiological functions of AHR that regulate cell proliferation were explored using the CRISPR/Cas9 system. The doubling-time of the AHR-KO clones of A549 and BEAS-2B was observed to be prolonged. The attenuation of proliferation potential was strongly associated with either the induction of p27Kip1 or the impairment in mitogenic signal transduction driven by the epidermal growth factor (EGF) and EGF receptor (EGFR). We found that the leucine-rich repeats and immunoglobulin-like domains 1 (LRIG1), a repressor of EGFR, was induced in the absence of AHR in vitro and in vivo. The LRIG1 tends to degrade via a proteasome dependent manner by interacting with AHR in wild-type cells. Either LRIG1 or a disintegrin and metalloprotease 17 (ADAM17) were accumulated in AHR-defective cells, consequently accelerating the degradation of EGFR, and attenuating the response to mitogenic stimulation. We also affirmed low AHR but high LRIG1 levels in lung tissues of chronic obstructive pulmonary disease (COPD) patients. This might partially elucidate the sluggish tissue repairment and developing inflammation in COPD patients.

scholarly journals Hydroquinone Exposure Worsens Rheumatoid Arthritis through the Activation of the Aryl Hydrocarbon Receptor and Interleukin-17 Pathways

Antioxidants ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 929
Author(s):  
Cintia Scucuglia Heluany ◽  
Paula Barbim Donate ◽  
Ayda Henriques Schneider ◽  
André Luis Fabris ◽  
Renan Augusto Gomes ◽  
...  
Keyword(s):  
Rheumatoid Arthritis ◽  
Gene Expression ◽  
Aryl Hydrocarbon Receptor ◽  
Cigarette Smoke ◽  
Cigarette Smoke Exposure ◽  
Interleukin 17 ◽  
Aryl Hydrocarbon ◽  
Tnf Α

Rheumatoid arthritis (RA) development is strongly associated with cigarette smoke exposure, which activates the aryl hydrocarbon receptor (AhR) as a trigger for Th17 inflammatory pathways. We previously demonstrated that the exposure to hydroquinone (HQ), one of the major compounds of cigarette tar, aggravates the arthritis symptomatology in rats. However, the mechanisms related to the HQ-related RA still remain elusive. Cell viability, cytokine secretion, and gene expression were measured in RA human fibroblast-like synoviocytes (RAHFLS) treated with HQ and stimulated or not with TNF-α. Antigen-induced arthritis (AIA) was also elicited in wild type (WT), AhR −/− or IL-17R −/− C57BL/6 mice upon daily exposure to nebulized HQ (25ppm) between days 15 to 21. At day 21, mice were challenged with mBSA and inflammatory parameters were assessed. The in vitro HQ treatment up-regulated TNFR1, TNFR2 expression, and increased ROS production. The co-treatment of HQ and TNF-α enhanced the IL-6 and IL-8 secretion. However, the pre-incubation of RAHFLS with an AhR antagonist inhibited the HQ-mediated cell proliferation and gene expression profile. About the in vivo approach, the HQ exposure worsened the AIA symptoms (edema, pain, cytokines secretion and NETs formation) in WT mice. These AIA effects were abolished in HQ-exposed AhR −/− and IL-17R −/− animals though. Our data demonstrated the harmful HQ influence over the onset of arthritis through the activation and proliferation of synoviocytes. The HQ-related RA severity was also associated with the activation of AhR and IL-17 pathways, highlighting how cigarette smoke compounds can contribute to the RA progression.

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