Investigating possible effects of aryl hydrocarbon receptor G1661A polymorphism on asthma severity in adults

Aryl hydrocarbon Receptor (AhR) is a ligand-activated transcription factor with an important role in lung health. The association of AhR polymorphisms with asthma severity has not been yet investigated. We analyzed the association of G1661A, the most prevalent polymorphism of AhR, with the asthma stages in a population-based study including 555 asthmatics (Intermittent: 93, Mild: 240, Moderate: 158, and Severe: 64). The SNP was genotyped using allele-specific PCR. Obtained data were analyzed using the Generalized-Ordered Logit Estimates. Genotypes GA (OR: 0.53, CI: 0.32-0.90, P=0.019) and AA (OR: 0.22, CI: 0.06-0.76, P=0.017) were associated with decreased risk of Severe, Moderate, Mild vs. Intermittent stage; and Severe, Moderate, vs. Mild, Intermittent stages respectively. However, Genotype GA (OR: 1.90, CI: 1.05-3.44, P=0.033), dominant model GA+AA (OR: 2.04, CI: 1.17-3.57, P=0.012), and allele A (OR: 1.68, CI: 1.06-2.66, P=0.027) were associated with increased risk of Severe stage vs. Moderate, Mild, Intermittent stages. Also, male sex and higher age were associated with an increased odds ratio for severe asthma. Furthermore, significant associations with asthma stages were found for the interactions of the SNP and sex, smoking, and alcohol consumption. In conclusion, we revealed that the mutant allele of AhR-G1661A may interact with independent variables and act as a protective factor against lower stages of asthma but it may increase the risk of severe asthma.

Targeting glutamine utilization to block metabolic adaptation of tumor cells under the stress of carboxyamidotriazole-induced nutrients unavailability

Tumor cells have unique metabolic programming that is biologically distinct from that of corresponding normal cells. Resetting tumor metabolic programming is a promising strategy to ameliorate drug resistance and improve the tumor microenvironment. Here, we show that carboxyamidotriazole (CAI), an anticancer drug, can function as a metabolic modulator that decreases glucose and lipid metabolism and increases the dependency of colon cancer cells on glutamine metabolism. CAI suppressed glucose and lipid metabolism utilization, causing inhibition of mitochondrial respiratory chain complex I, thus producing reactive oxygen species (ROS). In parallel, activation of the aryl hydrocarbon receptor (AhR) increased glutamine uptake via the transporter SLC1A5, which could activate the ROS-scavenging enzyme glutathione peroxidase. As a result, combined use of inhibitors of GLS/GDH1, CAI could effectively restrict colorectal cancer (CRC) energy metabolism. These data illuminate a new antitumor mechanism of CAI, suggesting a new strategy for CRC metabolic reprogramming treatment.

Tryptophan and tumor immunity / 药学学报

As an essential amino acid, tryptophan (Trp) has various physiological functions and is of great significance in the metabolic process of tumors. In the human body, tryptophan is mainly transformed through kynurenine metabolic pathway, which not only promotes the inherent malignant properties of tumor cells, but also leads to immune-suppressive tumor microenvironment. Changes in tryptophan metabolism often occur in tumors, accompanied by abnormal gene expression of tryptophan-related enzymes, among which indoleamine 2,3-bioxygenase (IDO)-related gene expression and tryptophan 2,3-dioxygenase (TDO)-related gene changes are the most significant. A large number of clinical trials on IDO inhibitors, TDO inhibitors and combination therapy have been carried out. This paper reviewed the tryptophan metabolic pathway, regulation of IDO (TDO), kynurenine (KYN) and other related genes in tumor cells, and outlined the development of therapeutic schedule targeting tryptophan-related genes. The new progress provides new ideas for the further exploration of tumor treatment options.

Effect of Jianpi Bufei Prescription on cAMP/PKA/CREB Signaling Pathway in Juvenile Asthma Rats / 中国实验方剂学杂志

Objective:To investigate the effect of Jianpi Bufei prescription （JPBFP） on airway inflammation， airway hyperresponsiveness （AHR）， and cyclic adenosine monophosphate （cAMP） signaling pathway activity in ovalbumin （OVA）-sensitized and challenged juvenile asthma rats. Method:Seventy-five male SD rats were randomly divided into a blank group （<italic>n</italic>=15） and an experimental group （<italic>n</italic>=60）. The rats in the experimental group were sensitized by aluminum hydroxide gel containing 0.2% OVA and stimulated by aerosol inhalation of normal saline containing 1% OVA to induce an asthma model， followed by assignment into the following groups： a model group （<italic>n</italic>=15）， a JPBFP group （<italic>n</italic>=15， 8.37 g·kg^-1·d^-1）， an aminophylline group （<italic>n</italic>=15， 40 mg·kg^-1·d^-1）， and a dexamethasone group （<italic>n</italic>=15， 0.1 mg·kg^-1·d^-1）. AHR was detected by the pulmonary function analyzer， changes in inflammatory cells by white blood cell （WBC） count and differential blood count in bronchoalveolar lavage fluid （BALF）， and pathological changes of lung tissues by hematoxylin-eosin （HE）， Masson， and periodic acid-schiff （PAS） staining. The interleukin （IL）-4， IL-5， IL-13， interferon （IFN）-<italic>γ</italic>， and tumor necrosis factor （TNF）-<italic>α</italic> levels in serum and the cAMP level in plasma were tested by the enzyme-linked immunosorbent assay （ELISA）. Protein kinase A （PKA） expression in lung tissues was detected by immunohistochemistry. The cAMP-response element-binding protein （CREB） mRNA and protein expression in lung tissues was detected by the real-time fluorescence quantitative polymerase chain reaction （Real-time PCR） and Western blot. Result:Compared with the blank group， the model group showed increased lung resistance， decreased pulmonary compliance （<italic>P</italic><0.05）， elevated WBC count and proportion of eosinophils in BALF （<italic>P</italic><0.05）， up-regulated levels of IL-4， IL-5， IL-13， and TNF-<italic>α</italic> in peripheral blood， declining IFN-<italic>γ</italic> level （<italic>P</italic><0.01）， severe pathological changes of lung tissues， dwindled cAMP， and down-regulated PKA and CREB expression （<italic>P</italic><0.01）. Compared with the model group， JPBFP inhibited AHR， reduced WBC count and proportion of eosinophils in BALF and lung resistance （<italic>P</italic><0.05）， improved pathological changes of lung tissues， increased pulmonary compliance， and up-regulated cAMP in serum and PKA and CREB expression in lung tissues （<italic>P</italic><0.01）. Conclusion:JPBFP can improve AHR， inhibit airway inflammation， and alleviate lung injury in asthma rats. Its mechanism may be related to the up-regulation of the activity of the cAMP/PKA/CREB signaling pathway.

Functional metabolomics reveal the role of AHR/GPR35 mediated kynurenic acid gradient sensing in chemotherapy-induced intestinal damage

Intestinal toxicity induced by chemotherapeutics has become an important reason for the interruption of therapy and withdrawal of approved agents. In this study, we demonstrated that chemotherapeutics-induced intestinal damage were commonly characterized by the sharp upregulation of tryptophan (Trp)-kynurenine (KYN)-kynurenic acid (KA) axis metabolism. Mechanistically, chemotherapy-induced intestinal damage triggered the formation of an interleukin-6 (IL-6)-indoleamine 2,3-dioxygenase 1 (IDO1)-aryl hydrocarbon receptor (AHR) positive feedback loop, which accelerated kynurenine pathway metabolism in gut. Besides, AHR and G protein-coupled receptor 35 (GPR35) negative feedback regulates intestinal damage and inflammation to maintain intestinal integrity and homeostasis through gradually sensing kynurenic acid level in gut and macrophage, respectively. Moreover, based on virtual screening and biological verification, vardenafil and linagliptin as GPR35 and AHR agonists respectively were discovered from 2388 approved drugs. Importantly, the results that vardenafil and linagliptin significantly alleviated chemotherapy-induced intestinal toxicity

Proteomics and metabolic phenotyping define principal roles for the aryl hydrocarbon receptor in mouse liver

Dioxin-like molecules have been associated with endocrine disruption and liver disease. To better understand aryl hydrocarbon receptor (AHR) biology, metabolic phenotyping and liver proteomics were performed in mice following ligand-activation or whole-body genetic ablation of this receptor. Male wild type (WT) and

Efeito da exposição a produtos fumígenos sobre a expressão de metalotioneínas durante a artrite experimental e sobre linfócitos T / Effect of exposure to tobacco-related products on metallothionein expression in the experimental arthritis and on T lymphocytes functions

Produtos liberados pela queima do cigarro convencional (CC) estão relacionados com a progressão clínica da artrite reumatoide (AR). Produtos fumígenos não combustíveis surgiram com a premissa de apresentarem menor toxicidade que o CC, dentre os quais está o tabaco aquecido (heat-not-burn tobacco; HNBT). Neste projeto investigamos os efeitos do HNBT sobre eventos envolvidos na AR, focando na sintomatologia, expressão de metalotioneínas (MTs), e na biologia de linfócitos T CD4+ primários e da linhagem Jurkat. Exposições in vivo ao ar, CC ou HNBT foram realizadas 2 vezes ao dia, 1 hora cada (12 CC ou 24 HNBT/hora), nos dias 14-21 da indução da artrite induzida por antígeno (AIA) em camundongos C57Bl/6. Foram realizadas análises dos parâmetros clínico da doenças, histopatologia e imunohistoquímica; quantificação de nicotina e cotinina séricas por cromatografia líquida acoplada a espectrometria de massas (MS). Os efeitos das exposições in vitro sobre linfócitos T foram mensurados por citometria de fluxo e ELISA. A concentração de metais emitidas pelo CC ou HNBT durante as exposições foram mensurados por MS com plasma acoplado. Camundongos expostos ao CC apresentaram intensa inflamação pulmonar, expressões acentuadas de MTs hepáticas e pulmonares e exacerbação dos parâmetros de AIA quando comparados ao grupo expostos ao HNBT. Animais expostos ao CC ou ao HNBT apresentaram redução na celularidade de órgãos linfoides. Somente a exposição in vitro ao CC causou estresse oxidativo e secreção de citocinas inflamatórias, ativação do receptor de hidrocarbonetos arila (AhR) e polarização de células Th17. Diferentemente, exposição ao CC ou ao HNBT provocaram redução da secreção de IL-2 e proliferação de células Jurkat. A exposição de células Jurkat à nicotina mimetizou os efeitos inibitórios da exposição ao HNBT sobre a secreção de IL-2 e proliferação de linfócitos T. O CC liberou maiores concentrações de metais nas câmaras de exposição. Associados, nossos resultados mostram que embora exposições ao HNBT não exacerbem parâmetros inflamatórios de AIA e nem em funções linfócitos T, ambos produtos prejudicam a celularidade de órgãos linfoides e a proliferação e secreção de IL-2 por linfócitos T

Products released by burning conventional cigarettes (CC) are related to the worsening of rheumatoid arthritis (RA). Non-combustible smoking products appeared with the premise of presenting less toxicity than the CC, among which is the heated tobacco (heat-not-burn tobacco; HNBT). Here, we investigate the effects of HNBT on events involved in RA, focusing on symptoms, expression of metallothioneins (MTs), and on the biology of primary CD4+ T lymphocytes and the Jurkat T cell lineage. In vivo exposures to air, CC or HNBT were performed twice a day, 1 hour each (12 CC or 24 HNBT / hour), on days 14-21 of the induction of antigen-induced arthritis (AIA) in C57Bl / 6 mice. Analyzes of the clinical parameters of the AIA, histopathology, and immunohistochemistry were performed; quantification of nicotine and cotinine by liquid chromatography coupled to mass spectrometry (MS). The in vitro effects of exposures on T lymphocytes were measured by flow cytometry and ELISA. The concentration of metals released by the CC or HNBT during the exposures was measured by MS with coupled plasma. Mice exposed to CC showed intense pulmonary inflammation, marked expressions of hepatic and pulmonary MTs, and exacerbation of AIA parameters when compared to the group exposed to HNBT. Animals exposed to CC or HNBT showed a reduction in the cellularity of lymphoid organs. Only in vitro exposure to CC caused oxidative stress and secretion of inflammatory cytokines, activation of the aryl hydrocarbon receptor (AhR), and polarization of Th17 cells. However, exposure to CC or HNBT led to reduced secretion of IL-2 and proliferation of Jurkat cells. The exposure of Jurkat T cells to nicotine mimicked the inhibitory effects of exposure to HNBT on IL-2 secretion and T lymphocyte proliferation. The CC released higher concentrations of metals in the exposure chambers. In association, our results show that although exposures to HNBT do not exacerbate inflammatory parameters of AIA or T lymphocyte functions, both products impair lymphoid organ cell function and the proliferation and secretion of IL-2 by T lymphocytes

Xenobiotic receptors in mediating the effect of sepsis on drug metabolism

Sepsis is an infection-induced systemic inflammatory syndrome. The immune response in sepsis is characterized by the activation of both proinflammatory and anti-inflammatory pathways. When sepsis occurs, the expression and activity of many inflammatory cytokines are markedly affected. Xenobiotic receptors are chemical-sensing transcription factors that play essential roles in the transcriptional regulation of drug-metabolizing enzymes (DMEs). Xenobiotic receptors mediate the functional crosstalk between sepsis and drug metabolism because the inflammatory cytokines released during sepsis can affect the expression and activity of xenobiotic receptors and thus impact the expression and activity of DMEs. Xenobiotic receptors in turn may affect the clinical outcomes of sepsis. This review focuses on the sepsis-induced inflammatory response and xenobiotic receptors such as pregnane X receptor (PXR), aryl hydrocarbon receptor (AHR), glucocorticoid receptor (GR), and constitutive androstane receptor (CAR), DMEs such as CYP1A, CYP2B6, CYP2C9, and CYP3A4, and drug transporters such as p-glycoprotein (P-gp), and multidrug resistance-associated protein (MRPs) that are affected by sepsis. Understanding the xenobiotic receptor-mediated effect of sepsis on drug metabolism will help to improve the safe use of drugs in sepsis patients and the development of new xenobiotic receptor-based therapeutic strategies for sepsis.

The gut microbiome: an orchestrator of xenobiotic metabolism

Microbes inhabiting the intestinal tract of humans represent a site for xenobiotic metabolism. The gut microbiome, the collection of microorganisms in the gastrointestinal tract, can alter the metabolic outcome of pharmaceuticals, environmental toxicants, and heavy metals, thereby changing their pharmacokinetics. Direct chemical modification of xenobiotics by the gut microbiome, either through the intestinal tract or re-entering the gut enterohepatic circulation, can lead to increased metabolism or bioactivation, depending on the enzymatic activity within the microbial niche. Unique enzymes encoded within the microbiome include those that reverse the modifications imparted by host detoxification pathways. Additionally, the microbiome can limit xenobiotic absorption in the small intestine by increasing the expression of cell-cell adhesion proteins, supporting the protective mucosal layer, and/or directly sequestering chemicals. Lastly, host gene expression is regulated by the microbiome, including CYP450s, multi-drug resistance proteins, and the transcription factors that regulate them. While the microbiome affects the host and pharmacokinetics of the xenobiotic, xenobiotics can also influence the viability and metabolism of the microbiome. Our understanding of the complex interconnectedness between host, microbiome, and metabolism will advance with new modeling systems, technology development and refinement, and mechanistic studies focused on the contribution of human and microbial metabolism.

Particulate Matter-Induced Aryl Hydrocarbon Receptor Regulates Autophagy in Keratinocytes

Particulate matter (PM), which refers to the mixture of particles present in the air, can have harmful effects. Damage to cells by PM, including disruption of organelles and proteins, can trigger autophagy, and the relationship between autophagy and PM has been well studied. However, the cellular regulators of PM-induced autophagy have not been well characterized, especially in keratinocytes. The Aryl Hydrocarbon Receptor (AhR) is expressed in the epidermis and is activated by PM. In this study, we investigated the role of the AhR in PM-induced autophagy in HaCaT cells. Our results showed that PM led to AhR activation in keratinocytes. Activation of the AhR-target gene CYP1A1 by PM was reduced by co-treatment with α-naphthoflavone (α-NF), an AhR inhibitor. We also evaluated activation of the autophagy pathway in PM-treated keratinocytes. In HaCaT cells, treatment with PM treatment led to the induction of microtubules-associated proteins light chain 3 (LC3) and p62/SQSTM1, which are essential components of the autophagy pathway. To study the role of the AhR in mediating PM-induced autophagy, we treated cells with α-NF or used an siRNA against AhR. Expression of LC3-ІІ induced by PM was decreased in a dose dependent manner by α-NF. Furthermore, knockdown of AhR with siAhR diminished PM-induced expression of LC3-ІІ and p62. Together, these results suggest that inhibition of the AhR decreases PM-induced autophagy. We confirmed these results using the autophagy-inhibitors BAF and 3-MA. Taken together, our results indicate that exposure to PM induces autophagy via the AhR in HaCaT keratinocytes.

Papel da exposição à Hidroquinona na artrite reumatoide experimental induzida pelo colágeno / Role of Hydroquinone exposure on experimental collagen-induced arthritis

Artrite reumatoide (AR) é uma doença autoimune, que causa inflamação crônica nas membranas sinoviais de diversas articulações. O modelo experimenal de artrite induzida pelo colágeno (AIC) é empregado para investigar os mecanismos da AR e para identificar potenciais agentes terapêuticos. Embora a etiologia da AR ainda seja desconhecida, há evidências que a AR se desenvolve em indivíduos predispostos geneticamente, após exposição a fatores ambientais, como o tabagismo, que se destaca como maior fator de risco para indução da AR e para o agravamento em pacientes com AR já estabelecida. Porém, o mecanismo efetivo da ação dos diversos componentes do cigarros ainda precisa ser elucidado. A Hidroquinona (HQ) é um composto fenólico, encontrada em concentração elevada no cigarro, com maior ativade pró-oxidativa, além de ser produto da biotransformação do benzeno, também encontrado no cigarro. Neste caso, a HQ é responsável pela imunotoxicidade e mielotoxicidade do benzeno. Devido a alta exposição de fumantes à HQ e a associação do tabagismo com a AR, investigamos se a exposição à HQ teria participação no desenvolvimento da AIC em ratos Wistar. Para tanto, animais foram expostos à HQ em diferentes protocolos experimentais, a saber: A - por 35 dias consecutivos, durante fase de indução e desenvolvimento da artrite; B - por 14 dias consecutivos, até a segunda injeção de colágeno, na fase de sensibilização e indução da AIC; C - por 7 dias consecutivos, do 29º ao 35º dia, na fase posterior ao desenvolvimento da AIC. Os resultados obtidos mostraram que a HQ agravou a AR nos 3 grupos experimentais, aumentando os parâmetros clínicos, o número de células no líquido sinovial, a inflamação nas sinóvias, caracterizada por maior influxo de neutrófilos, proliferação de sinoviócitos (histologia por HE e imunohistoquímica), aumento nos níveis de IL-6 e IL-1ß (ELISA) no líquido sinovial e rearranjo do colágeno na sinóvia (microscopia por segundo harmônico). No entanto, os efeitos mais acentuados foram observados em animais dos grupos A e C, que também tiveram perda de peso significativa. Ademais, exposição à HQ, nos 3 grupos experimentais, causou expressão aumentada do receptor aril hidrocarboneto (AhR), um receptor ativado por xenobióticos durante a AR, e aumento nos níveis do fator de transcrição ROR e de IL-17 na sinóvia. Como AhR/ROR/IL-17 em linfócitos e neutrófilos é uma via importante na gênese da AR, ensaios in vitro foram realizados para elucidar o papel da HQ nesta via. A incubação com HQ in vitro de esplenócitos de animais naive elevou a expressão de AhR e de secreção de IL-17 (por citometria de fluxo), as quais foram bloqueadas pelo antagonista de AhR (α-naftoflavona). Em conjunto, os resultados obtidos nos permitem concluir que a HQ, como um importante componente do cigarro agrava a CIA em ratos, e a ativação via AhR/IL-17 é um possível mecanismo da patogênese da artrite

Rheumatoid arthritis (RA) is an autoimmune disease that causes chronic inflammation in the joint synovial membranes. The experimental model of collagen-induced arthritis (CIA) is used to investigate the involved mechanisms in RA and to identify novel therapeutic agents. The genesis of RA is multifactorial, involving interplay of genetic and environmental factors and smoking is the trigger factor in the development or RA and worsens the pre-existing RA but the mechanisms undlerlying are yet to be elucidated. Hydroquinone (HQ) is a phenolic compound, found in high concentrations in cigarette, where HQ is the major oxidative component. Moreover, HQ is benzene metabolite, which is also found in cigarette smoke, being responsible for the myelotoxicity and immunotoxicity detected during benzene exposure. Due to this association, we aimed to investigate the role of HQ exposure on CIA development in Wistar rats and the involved mechanisms. Animals were exposed to HQ according to different protocols: A - during 35 consecutive days, during the sensitization and devolpment phases of the disease; B - during 14 consecutive days, until the second injection of collagen, during the sensitization phase; C - during 7 consecutive days, from day 29 to 35, after the development phase of CIA. The results showed that HQ worsened the RA in the 3 experimental protocols, HQ elevated the clinical parameters of CIA development, increased inflammation in the synovial membrane, characterized by increased influx of neutrophis, synoviocytes proliferation (visualized by Immunohistochemistry and Histology analysis), augmented the levels of IL-6 and IL-1ß in the synovial fluid (ELISA assay) and led to intense collagen deposition on the synovia. The most pronounced effects where observed in animals from groups A and C, which also had weight body loss. In addition, in the 3 protocols, HQ exposure also increased the expression of AhR receptor, a receptor activated by xenobiotics during RA, and increased the expression of ROR and levels of IL-17 secretion in the synovial membranes. As AhR/ROR/IL-17 in lymphocytes and neutrophils is an important pathway involved in the genesis of RA, in vitro studies have been performed to elucidate the role of HQ exposure in this pathway. The HQ in vitro treatment augmented the expression of AhR and secretion of IL-17 by splenocytes (FACS assay) and the administration of an AhR antagonist (α-naphtoflavone) blocked these effects. Taken together, the results obtained here allow us to conclude that HQ, as an important cigarette component, aggravates CIA in rats, and the activation of AhR/IL-17 pathway is a possible mechanism involved in the RA pathogenesis

Ginsenoside Rb1 Inhibits Doxorubicin-Triggered H9C2 Cell Apoptosis via Aryl Hydrocarbon Receptor

Doxorubicin (DOX) is a highly effective chemotherapeutic agent; however, the dose-dependent cardiotoxicity associated with DOX significantly limits its clinical application. In the present study, we investigated whether Rb1 could prevent DOX-induced apoptosis in H9C2 cells via aryl hydrocarbon receptor (AhR). H9C2 cells were treated with various concentrations (−μM) of Rb1. AhR, CYP1A protein and mRNA expression were quantified with Western blot and real-time PCR analyses. We also evaluated the expression levels of caspase-3 to assess the anti-apoptotic effects of Rb1. Our results showed that Rb1 attenuated DOX-induced cardiomyocytes injury and apoptosis and reduced caspase-3 and caspase-8, but not caspase-9 activity in DOX-treated H9C2 cells. Meanwhile, pre-treatment with Rb1 decreased the expression of caspase-3 and PARP in the protein levels, with no effects on cytochrome c, Bax, and Bcl-2 in DOX-stimulated cells. Rb1 markedly decreased the CYP1A1 and CYP1A2 expression induced by DOX. Furthermore, transfection with AhR siRNA or pre-treatment with AhR antagonist CH-223191 significantly inhibited the ability of Rb1 to decrease the induction of CYP1A, as well as caspase-3 protein levels following stimulation with DOX. In conclusion, these findings indicate that AhR plays an important role in the protection of Ginsenoside Rb1 against DOX-triggered apoptosis of H9C2 cells.

Study on the induction of drug metabolizing enzyme CYP1 A1 activity by Ginsenoside Rc,Re,Rf and Rg1 / 中国药理学通报

Aim To investigate the induction effect of ginsenoside Rc, Re, Rf and Rg1 on CYP1A1, and further validate the role of aryl hydrocarbon receptor in CYP1A1 expression. Methods Dual luciferase re-porter gene system was performed. Four kinds of gin-senoside were screened for aryl hydrocarbon receptor activation by reporter assays, and TCDD as the positive control. Further with different concentrations of ginsen-oside Rc, Re, Rf and Rg1 treated on LS174T cells, RNA and total protein were extracted to detect the reg-ulating effect of ginsenosides on CYP1 A1 mRNA and protein expression with Real-time PCR and Western blot technology respectively. Results Reporter gene screening showed that the ginsenoside Rc, Re, Rf and Rg1 could activate AhR and had potential effects on the induction of CYP1A1 enzyme. Meanwhile, dose-de-pendent induction of the gene expression were observed in response to ginsenoside Rc, Re, Rf and Rg1 and the levels of CYP1 A1 protein expression were increased by ginsenoside Rc, Re, Rf and Rg1 in varying de-grees. Conclusion Ginsenoside Rc, Re, Rf and Rg1 can up-regulate the gene and protein expression of CYP1 A1 possibly via the AhR-mediated CYP1 A1 path-way.

3,3'-Diindolylmethane Inhibits Flt3L/GM-CSF-induced-bone Marrow-derived CD103+ Dendritic Cell Differentiation Regulating Phosphorylation of STAT3 and STAT5

The intestinal immune system maintains oral tolerance to harmless antigens or nutrients. One mechanism of oral tolerance is mediated by regulatory T cell (Treg)s, of which differentiation is regulated by a subset of dendritic cell (DC)s, primarily CD103+ DCs. The aryl hydrocarbon receptor (AhR), a ligand-activated transcription factor, plays an important role in regulating immunity. The intestines are exposed to various AhR ligands, including endogenous metabolites and phytochemicals. It was previously reported that AhR activation induced tolerogenic DCs in mice or in cultures of bone marrow-derived DCs. However, given the variety of tolerogenic DCs, which type of tolerogenic DCs is regulated by AhR remains unknown. In this study, we found that AhR ligand 3,3'-diindolylmethane (DIM) inhibited the development of CD103+ DCs from mouse bone marrow cells stimulated with Flt3L and GM-CSF. DIM interfered with phosphorylation of STAT3 and STAT5 inhibiting the expression of genes, including Id2, E2-2, IDO-1, and Aldh1a2, which are associated with DC differentiation and functions. Finally, DIM suppressed the ability of CD103+ DCs to induce Foxp3+ Tregs.

The effect of AHR small interference on hepatoma HCCLM3 cell proliferation in vitro and tumor growth in vivo / 肿瘤

Objective: To investigate the effect of aryl hydrocarbon receptor (AHR) RNA interference on hepatoma HCCLM3 cell proliferation and migration and to explore its possible mechanism. Methods: After HCCLM3 cells transfection with specific AHR-small interference RNA (siRNA), the expression level of AHR mRNA was detected by real-time fluorescence quantitative-PCR, and the expression levels of AHR, stress-activated protein kinases (SAPK)/c-Jun N-terminal kinase (JNK), extracellular signal-regulated kinase 1/2 (ERK 1/2) and c-Jun phosphorylation were detected by Western blotting. Then the proliferation and migration of HCCLM3 cells after transfection with AHR-siRNA were detected by cell counting kit-8 (CCK-8) and Transwell assay, respectively. Synthesize AHR gene-specific small hairpin RNA (shRNA) to construct recombinant virus vector pMKO.1/puro-shAHR which stable knockdown AHR, and the recombinant vector was infected into HCCLM3 cells and then implanted into nude mice to construct subcutaneous tumor model. The growth of xenografted tumor in nude mice was examined. The expression levels of AHR protein in HCCLM3 cells and xenografted tumor tissues after infection with pMKO.1/puro-shAHR were detected by Western blotting. Results: The expression levels of AHR mRNA and protein were significantly reduced in HCCLM3 cells transfected with AHR-siRNA (P < 0.01), and the proliferation and migration of HCCLM3 cells were inhibited (P < 0.01). The expression levels of SAPK/JNK, ERK 1/2 and c-Jun phosphorylation were depressed (P < 0.01). The volume and weight of HCCLM3 cells xenografted tumor in nude mice after infection with pMKO.1/puro-shAHR were lower than those of the control group (HCCLM3 cells were infected with pMKO.1/puro-shNC) (P < 0.01). The expression levels of AHR protein in HCCLM3 cells and xenografted tissues after infection with pMKO.1/puro-shAHR were decreased (P < 0.01). Conclusion: AHR may promote HCCLM3 cell proliferation and migration in vitro by up-regulating the phosphorylation levels of ERK1/2, SAPK/JNK and c-Jun. Copyright © 2014 by TUMOR.

Efeitos da participação de esteroides-like provenientes da poluição atmosférica no epitélio das vias aéreas em camundongos machos e fêmeas / Effects of the participation of steroid-like compounds from air pollution in the airway epithelium of male and female mice

O epitélio nasal é a primeira porção do sistema respiratório a entrar em contato com o ambiente externo. Partículas da poluição do ar, principalmente os compostos orgânicos absorvidos, podem atuar como liberadores endócrinos. O receptor aril hidrocarboneto (AhR) é um importante competidor dos receptores de estrógeno-beta (ERbeta) que regulam a transcrição do gene para enzimas de metabolização xenobióticas (enzimas do citocromo P450). O objetivo deste estudo é identificar e quantificar ERbeta, AhR, CYP1A1, CYP1A2, CYP1B1 e o perfil de muco no epitélio nasal de camundongos machos e fêmeas em diferentes fases do ciclo estral. Camundongos BALB/c machos (n=32) e fêmeas (n=84) foram expostos ao ar ambiente e ao MP2,5 concentrado a 600 ug.m-³ em um concentrador de partículas ambientais (CPAs). As fêmeas foram divididas de acordo com as fases do ciclo estral: proestro, estro e diestro. O epitélio nasal foi avaliado por RT-PCR e imuno-histoquímica para análise de expressão de ERbeta (proteína), Erbeta-1 e Erbeta-2 (gene), AhR (proteína e gene) e Cyp1a1, Cyp1a2 and Cyp1b1 (gene). A quantificação de muco neutro - Periodic Acid Schiff's (PAS+) e ácido - Alcian Blue (AB+) foi avaliada por morfometria. As exposições foram realizadas durante 5 dias/semana, por 45 ± 55 dias. A expressão de Erbeta-2 RNAm apresentou diferenças em resposta à exposição ao CPAs (p=0,016), bem como uma diminuição em fêmeas, quando comparadas aos camundongos machos (p=0,036). A expressão de Cyp1b1 RNAm foi significantemente menor no grupo exposto ao CPAs, em relação ao grupo exposto ao ar ambiente nas fêmeas em diestro (p=0,036). A expressão de Erbeta foi aumentada no epitélio nasal de fêmeas em estro expostas ao CPAs (p=0,005) e a expressão de AhR foi menor em fêmeas em proestro expostas ao CPAs (p=0,048). A exposição ao CPAs levou ao aumento do conteúdo de muco ácido em camundongos machos (p=0,048), o qual diminuiu em fêmeas (p=0,040), quando comparados ao grupo ar ambiente. Este estudo mostrou...

The nasal epithelium is the first portion of the respiratory system to reach contact with the external environment. Air pollution particles, mainly the organic compounds absorbed into them, may act as endocrine releasers. The aryl hydrocarbon (AhR) receptor is an important competitor of estrogenic receptors-beta (ERbeta) that regulate transcription of gene coding for xenobiotic-metabolizing enzymes (cytochrome P450 enzymes). The aim of this study is to identify and quantify in the nasal epithelium of male and female mice in different estrous cycle phases related with ERbeta, AhR, CYP1A1, 1A2, 1B1 and the mucus profile. Male (n=32) and female (n=84) BALB/c mice were exposed to ambient air and PM2.5 concentrated at 600 ug.m-³ in an ambient particle concentrator with a particulate matter diameter of 2.5 um (PM2.5). Females were subdivided in three estrous cycles: proestrus, estrus and diestrus. Nasal epithelium was evaluated through RT-PCR and immunohistochemistry for the expression of ERbeta (protein), Erbeta-1 and Erbeta-2 (gene expression), AhR (protein and gene expression) and Cyp1a1, Cyp1a2 and Cyp1b1 (gene expression). Morphometry was applied for evaluation of mucus profile: acid - Alcian Blue (AB+) and neutral - Periodic Acid Schiff's (PAS+). Exposure happened for 5 days/week, for 45 ± 55 days. There were differences in Erbeta-2 mRNA in response to exposition to CPAs (p=0.016), and a significant decrease in female compared male mice (p=0.036). Cyp1b1 mRNA was significantly smaller in the CPAs-exposed group compared with the ambient air group in diestrus female mice (p=0.036). The ERbeta expression increased in the nasal epithelium of CPAs-exposed females in the estrus cycle (p=0.005), and the AhR expression decreased in the proestrus cycle of CPAs-exposed females (p=0.048). The exposure to the CPAs led to an increase in the acidic content of mucus in male mice (p=0.048), and decreased in female mice (p=0.040), compared to the ambient air group. This...

2,3,7,8-Tetrachlorodibenzo-P-Dioxin Induced Cell-Specific Drug Transporters With Acquired Cisplatin Resistance in Cisplatin Sensitive Cancer Cells

2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) can induce drug transporter genes such as the ATP-binding cassette G member 2 (ABCG2), which contributes to multidrug resistance. We investigated the effect of TCDD pretreatment on drug transporters induction from cancer cells of various origins. Cell viabilities after treatment of cisplatin were measured to evaluate acquiring cisplatin resistance by TCDD. Acquring cisplatin resistance was found only in cisplatin senstivie cancer cells including gastric SNU601, colon LS180, brain CRT-MG and lymphoma Jurkat cells which showed a significant increase in cell viability after combined treatment with TCDD and cisplatin. High increase of ABCG2 gene expression was found in SNU601 and LS180 cells with a mild increase in the expression of the ABCC3, ABCC5,and SLC29A2 genes in SNU601 cells, and of major vault protein (MVP) in LS180 cells. The AhR inhibitor kaempferol suppressed the upregulation of ABCG2 expression and reversed the TCDD-induced increase in cell viability in LS180 cells. However, in CRT-MG cells, other transporter genes including ABCC1, ABCC5, ABCA3, ABCA2, ABCB4, ABCG1, and SLC29A1 were up-regulated. These findings suggested the acquiring cisplatin resistance by TCDD associated with cancer cell-type-specific induction of drug transporters.

2,3,7,8-Tetrachlorodibenzo-P-Dioxin Induced Cell-Specific Drug Transporters With Acquired Cisplatin Resistance in Cisplatin Sensitive Cancer Cells

2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) can induce drug transporter genes such as the ATP-binding cassette G member 2 (ABCG2), which contributes to multidrug resistance. We investigated the effect of TCDD pretreatment on drug transporters induction from cancer cells of various origins. Cell viabilities after treatment of cisplatin were measured to evaluate acquiring cisplatin resistance by TCDD. Acquring cisplatin resistance was found only in cisplatin senstivie cancer cells including gastric SNU601, colon LS180, brain CRT-MG and lymphoma Jurkat cells which showed a significant increase in cell viability after combined treatment with TCDD and cisplatin. High increase of ABCG2 gene expression was found in SNU601 and LS180 cells with a mild increase in the expression of the ABCC3, ABCC5,and SLC29A2 genes in SNU601 cells, and of major vault protein (MVP) in LS180 cells. The AhR inhibitor kaempferol suppressed the upregulation of ABCG2 expression and reversed the TCDD-induced increase in cell viability in LS180 cells. However, in CRT-MG cells, other transporter genes including ABCC1, ABCC5, ABCA3, ABCA2, ABCB4, ABCG1, and SLC29A1 were up-regulated. These findings suggested the acquiring cisplatin resistance by TCDD associated with cancer cell-type-specific induction of drug transporters.

Influência dos alelos R e S do gene Slc11a1 na suscetibilidade à carcinogênese de pele induzida por 7, 12-dimetilbenzantraceno / Influence of R and S alleles of Slc11a1 gene in the susceptibility to skin cancer induced by 7 12-Dimethylbenz[a]anthracene

Camundongos AIRmax e AIRmin diferem na sensibilidade à carcinogênese, sendo os AIRmin mais sensíveis à carcinogênese de pele devido ao seu fundo genético e um polimorfismo no gene Ahr. Mais que isso, estas linhagens possuem um desequilíbrio de frequência dos alelos do gene Slc11a1. Para estudar a interação dos alelos de resistência (R) ou suscetibilidade (S) do gene Slc11a1 com os loci de resposta inflamatória aguda dos animais AIRmax e AIRmin, foram produzidas sublinhagens homozigotas para estes alelos:AIRmaxRR, AIRmaxSS, AIRminRR e AIRminSS. Nosso objetivo foi investigar a diferença de sensibilidade à carcinogênese de pele induzida por DMBA nestas sublinhagens. A incidência de câncer de pele foi de 7% nos animais AIRminRR e de 13% nos animais AIRminSS.Os animais AIRmaxSS não apresentaram câncer de pele, mas a incidência de câncer em órgãos internos foi 100% nesta sublinhagem.Esses dados mostraram que os camundongos AIRmaxSS tem maior suscetibilidade à carcinogênese, sugerindo que o alelo S, no fundo genético AIRmax, pode influenciar na suscetibilidade ao câncer.

Mice AIRmax and AIRmin differ on sensibility to carcinogenesis. AIRmin mice are significantly more sensitive to skin carcinogenesis than AIRmax mice due to the genetic background and the polymorphism of aryl hydrocarbon receptor (Ahr) gene. Furthermore,these mice have an imbalance of frequency of Slc11a1 gene alleles.To study the interaction of resistant (R) or susceptible (S) Slc11a1 alleles with acute inflammatory reaction loci found in AIRmax and AIRmin mice, homozygous sublines for these alleles were produced: AIRmaxRR, AIRmaxSS, AIRminRR and AIRminSS. The objective of this study was to investigate the difference in skin carcinogenesis sensibility induced by DMBA agent in these sublines.The incidence of skin cancer was 7% in AIRminRR mice and 13% in AIRminSS mice.AIRmaxRR and AIRmaxSS mice did not show skin cancer, but the incidence of internal organs cancer was 100% only in AIRmaxSS mice. These data showed that AIRmaxSS animals have higher susceptibility, suggesting that the S allele in the AIRmax background could influence susceptible to cancer.

Chlorination of ortho-position on Polychlorinated Biphenyls Increases Protein Kinase C Activity in Neuronal Cells

Polychlorinated biphenyls (PCBs) are persistent and bioaccumulative environmental pollutants. Recently, it is suggested that neurotoxic effects such as motor dysfunction and impairment in memory and learning have been associated with PCB exposure. However, structure relationship of PCB congeners with neurotoxic effects remains unknown. Since PKC signaling pathway is implicated in the modulation of motor behavior as well as learning and memory and the role of PKC are subspecies-specific, we attempted to study the effects of structurally distinct PCBs on the total PKC activity as well as subspecies of PKC in cerebellar granule cell culture model. Cells were exposed to 0, 25 and 50 microM of PCB-126, PCB-169, PCB-114, PCB-157, PCB-52 and PCB-4 for 15 min. Cells were subsequently analyzed by [3H] phorbol ester binding assay or immunoblotted against PKC-alpha and -epsilon monoclonal antibodies. While non-dioxin-like-PCB (PCB-52 and PCB-4) induced a translocation of PKC-alpha and -epsilon from cytosol to membrane fraction, dioxin-like PCBs (PCB-126, -169, -114, -157) had no effects. [3H] Phorbol ester binding assay also revealed structure-dependent increase similar to translocation of PKC isozymes. While PCB-4 induced translocation of PKC-alpha and -epsilon was inhibited by ROS inhibitor, the pattern of translocation was not affected in presence of AhR inhibitor. It is suggested that PCB-4-induced PKC activity may not be mediated via AhR-dependent pathway. Taken together, our findings suggest that chlorination of ortho-position in PCB may be a critical structural moiety associated with neurotoxic effects, which may be preferentially mediated via non-AhR-dependent pathway. Therefore, the present study may contribute to understanding the neurotoxic mechanism of PCBs as well as providing a basis for establishing a better neurotoxic assessment.