MicroRNAs (miRNAs) are a small group of RNAs that are emerging as a new avenue by which autoimmune diseases may be modulated. Accumulating evidence shows that miRNAs are involved in the pathogenesis of MS; however, the interaction of miRNAs with environmentally responsive transcription factors that play prominent roles in MS is unexplored. The activation of aryl hydrocarbon receptor by 2,3,7,8-tetrachlorodibenzo-pdioxin (TCDD) alleviates inflammation in experimental autoimmune encephalomyelitis (EAE), the best available model of MS. Therefore, we predicted that TCDD could attenuate EAE by inducing miRNA(s) targeting inflammatory mediators. Here, we show that TCDD induces cholinergic anti-inflammation in EAE mice by upregulating acetylcholinesterasetargeting miR-132. The expression of miR-132 was downregulated in CD4 + cells and associated with EAE severity, while TCDD treatment attenuated EAE by inducing the miR-132/acetylcholinesterase module. Silencing miR-132 in vivo abolished TCDDinduced cholinergic anti-inflammation and aggravated EAE. Overexpression of miR-132 in encephalitogenic CD4 + cells decreased IL-17 and IFN-γ and suppressed T-cell proliferation. In conclusion, our findings identify a new miRNA-based mechanism through which miR-132 mediates TCDD-induced EAE attenuation, suggesting that miR-132 could be a promising therapeutic target for anti-inflammatory treatment of MS.Keywords: Ahr r Cholinergic anti-inflammation r EAE · MicroRNA r miR-132 r TCDD Additional supporting information may be found in the online version of this article at the publisher's web-site IntroductionThe aryl hydrocarbon receptor (Ahr) is a ligand-dependent transcription factor activated by a long list of exogenous ligands including 2,3,7, [1] and 3-methylcholanthrene [2]. Ahr has been shown to mediate the mechanisms that underlie environmental and immunotoxicity [3]. Therefore, Ahr represents a fascinating link between the environment and the immune system. Previously, we and others have Correspondence: Dr. Hanieh Hamza e-mail: hhanieh@kfu.edu.sa demonstrated that Ahr is implicated in the differentiation of Th17/Treg cells [4][5][6], development of autoimmunity [7], and secretion of proinflammatory cytokines [8,9]. Importantly, activation of Ahr has shown a therapeutic potential for autoimmune inflammation. For example, TCDD mitigates CNS inflammation in experimental autoimmune encephalomyelitis (EAE) [5], an established animal model of MS. However, the toxicity of TCDD prohibits its clinical application, and therefore, mechanistic explanation of TCDD-attenuated inflammation may open intriguing possibilities for applicable treatment of MS in human.The microRNAs (miRNAs) are small endogenous noncoding RNAs of ∼22 nt that post-transcriptionally regulate gene expression. These molecules are implicated in different aspects of C 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim www.eji-journal.eu Hanieh Hamza and Alzahrani AbdullahEur. J. Immunol. 2013Immunol. . 43: 2771Immunol. -2782 inflammation. For instance, miR-155, miR-146a, a...

BackgroundDespite the remarkable progress to fight against breast cancer, metastasis remains the dominant cause of treatment failure and recurrence. Therefore, control of invasiveness potential of breast cancer cells is crucial. Accumulating evidences suggest Aryl hydrocarbon receptor (Ahr), a helix-loop-helix transcription factor, as a promising target to control migration and invasion in breast cancer cells. Thus, an Ahr-based exploration was performed to identify a new Ahr agonist with inhibitory potentials on cancer cell motility.MethodsFor prediction of potential interactions between Ahr and candidate molecules, bioinformatics analysis was carried out. The interaction of the selected ligand with Ahr and its effects on migration and invasion were examined in vitro using the MDA-MB-231 and T47D cell lines. The silencing RNAs were transfected into cells by electroporation. Expressions of microRNAs (miRNAs) and coding genes were quantified by real-time PCR, and the protein levels were detected by western blot.ResultsThe in silico and in vitro results identified Flavipin as a novel Ahr agonist. It induces formation of Ahr/Ahr nuclear translocator (Arnt) heterodimer to promote the expression of cytochrome P450 family 1 subfamily A member 1 (Cyp1a1). Migration and invasion of MDA-MB-231 and T47D cells were inhibited with Flavipin treatment in an Ahr-dependent fashion. Interestingly, Flavipin suppressed the pro-metastatic factor SRY-related HMG-box4 (Sox4) by inducing miR-212/132 cluster. Moreover, Flavipin inhibited growth and adhesion of both cell lines by suppressing gene expressions of B-cell lymphoma 2 (Bcl2) and integrinα4 (ITGA4).ConclusionTaken together, the results introduce Flavipin as a novel Ahr agonist, and provide first evidences on its inhibitory effects on cancer cell motility, suggesting Flavipin as a candidate to control cell invasiveness in breast cancer patients.

Background Multiple sclerosis (MS) is a widespread neurological autoimmune disease that includes episodes of demyelination in the central nervous system (CNS). The accumulated evidence has suggested that aryl hydrocarbon receptor (Ahr), a ligand-activated transcription factor, is a promising treatment target for MS. Thus, the current study aimed to identify a novel Ahr ligand with anti-inflammatory potential in experimental autoimmune encephalomyelitis (EAE). Methods An in silico analysis was carried out to predict interactions between Ahr and potential natural ligands. The effects of a predicted interaction were examined in vitro using CD4 + T cells under T helper17 (Th17) cell-polarizing conditions and lipopolysaccharide (LPS)-stimulated macrophages. Silencing Ahr and microRNA (miR)-132 was achieved by electroporation. Myelin oligodendrocyte glycoprotein (MOG) 35-55 and the adoptive transfer of encephalitogenic CD4 + T cells were used to induce EAE. Results Molecular docking analysis and in vitro data identified gallic acid (GA) as a novel Ahr ligand with potent activation potential. GA induced the expression of Ahr downstream genes, including cytochrome P450 family 1 subfamily A member 1 ( Cyp1a1 ) and the miR-212/132 cluster, and promoted the formation of the Ahr/Ahr nuclear translocator (Arnt) complex. In vivo , GA-treated mice were resistant to EAE and exhibited reduced levels of proinflammatory cytokines and increased levels of transforming growth factor-β (TGF-β). Furthermore, GA reduced infiltration of CD4 + CD45 + T cells and monocytes into the CNS. The anti-inflammatory effects of GA were concomitant with miR-132-potentiated cholinergic anti-inflammation and the regulation of the pathogenic potential of astrocytes and microglia. Inducing EAE by adoptive transfer revealed that CD4 + T cells were not entirely responsible for the ameliorative effects of GA. Conclusion Our findings identify GA as a novel Ahr ligand and provide molecular mechanisms elucidating the ameliorative effects of GA on EAE, suggesting that GA is a potential therapeutic agent to control inflammation in autoimmune diseases such as MS.

Our findings identify miR-132 as a new molecule implicated in CAC pathogenesis, and reveal that miR-132 mediates the ameliorating effects of TCDD on CAC, suggesting miR-132 as a promising therapeutic candidate to control autoimmune inflammation and tumorigenesis in CAC patients.

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Polymorphisms in the genes encoding CYP2C9 enzyme and VKORC1 reductase significantly influence the dose variability of coumarinic oral anticoagulants (COAs). Substantial inter- and intraethnic variability exists in the frequencies of CYP2C9 ∗2 and ∗3 and VKORC1 –1639A alleles. However, the prevalence of CYP2C9 and VKORC1 genetic variants is less characterized in Arab populations. A total of 131 healthy adult subjects from the Al-Ahsa region of Saudi Arabia were genotyped for the CYP2C9 ∗2 and ∗3 and VKORC1 –1639G>A polymorphisms by PCR-RFLP method. The frequencies of the CYP2C9 ∗2 and ∗3 and VKORC1 –1639A alleles were 13.3%, 2.3%, and 42.4%, respectively, with no subjects carrying 2 defective alleles. The frequencies of the CYP2C9 ∗3 and VKORC1 –1639A alleles were significantly lower than those reported in different Arabian populations. None of the subjects with the VKORC1 –1639AA genotype were carriers of CYP2C9 ∗1/∗3 genotypes that lead to sensitivity to COAs therapy. The low frequency of the CYP2C9 ∗3 allele combined with the absence of subjects carrying 2 defective CYP2C9 alleles suggests that, in this specific population, pharmacogenetic COAs dosing may mostly rely upon VKORC1 genotyping.

Purpose. Our physiopathological assumption is that u-PA, t-PA, and PAI-1 are released by calcified aortic valves and play a role in the calcification of these valves. Methods. Sixty-five calcified aortic valves were collected from patients suffering from aortic stenosis. Each valve was incubated for 24 hours in culture medium. The supernatants were used to measure u-PA, t-PA, and PAI-1 concentrations; the valve calcification was evaluated using biphotonic absorptiometry. Results. Aortic stenosis valves expressed normal plasminogen activators concentrations and overexpressed PAI-1 (u-PA, t-PA, and PAI-1 mean concentrations were, resp., 1.69 ng/mL ± 0.80, 2.76 ng/mL ± 1.33, and 53.27 ng/mL ± 36.39). There was no correlation between u-PA and PAI-1 (r = 0.3) but t-PA and PAI-1 were strongly correlated with each other (r = 0.6). Overexpression of PAI-1 was proportional to the calcium content of the AS valves. Conclusions. Our results demonstrate a consistent increase of PAI-1 proportional to the calcification. The overexpression of PAI-1 may be useful as a predictive indicator in patients with aortic stenosis.

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