Publications by authors named "J Vondracek"

Aryl hydrocarbon receptor (AhR) is a transcription factor that is primarily known as an intracellular sensor of environmental pollution. After five decades, the list of synthetic and toxic chemicals that activate AhR signaling has been extended to include a number of endogenous compounds produced by various types of cells via their metabolic activity. AhR signaling is active from the very beginning of embryonal development throughout the life cycle and participates in numerous biological processes such as control of cell proliferation and differentiation, metabolism of aromatic compounds of endogenous and exogenous origin, tissue regeneration and stratification, immune system development and polarization, control of stemness potential, and homeostasis maintenance.

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The role of benzo[a]pyrene (BaP), a prominent genotoxic carcinogen and aryl hydrocarbon receptor (AhR) ligand, in tumor progression remains poorly characterized. We investigated the impact of BaP on the process of epithelial-mesenchymal transition (EMT) in normal human bronchial epithelial HBEC-12KT cells. Early morphological changes after 2-week exposure were accompanied with induction of SERPINB2, IL1, CDKN1A/p21 (linked with cell cycle delay) and chemokine CXCL5.

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Microbial indoles have been demonstrated as selective or dual agonists and ligands of the pregnane X receptor (PXR) and aryl hydrocarbon receptor (AhR). However, structural determinants of microbial indoles selectivity towards both receptors remain elusive. Here, we studied the effects of existing and newly synthesized derivatives of indole microbial metabolite tryptamine on the activity of AhR and PXR receptors.

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Article Synopsis
  • * Key components, like polycyclic aromatic hydrocarbons (PAHs), activate the aryl hydrocarbon receptor (AhR), leading to processes that promote tumor development, including DNA damage and oxidative stress.
  • * It appears that lung cancer associated with outdoor air pollution primarily promotes tumor growth in cells with pre-existing genetic mutations rather than causing typical mutations directly, indicating different mechanisms at play compared to smoking-related lung cancer.
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Both aryl hydrocarbon receptor (AhR) and pregnane X receptor (PXR) belong among key regulators of xenobiotic metabolism in the intestinal tissue. AhR in particular is activated by a wide range of environmental and dietary carcinogens. The data accumulated over the last two decades suggest that both of these transcriptional regulators play a much wider role in the maintenance of gut homeostasis, and that both transcription factors may affect processes linked with intestinal tumorigenesis.

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