title: Hypoxic Stress Induced by Hydralazine Leads to a Loss of Blood-Brain Barrier Integrity and an Increase in Efflux Transporter Activity.
abstract: Understanding cellular and molecular mechanisms induced by hypoxic stress is crucial to reduce blood-brain barrier (BBB) disruption in some neurological diseases. Since the brain is a complex organ, it makes the interpretation of in vivo data difficult, so BBB studies are often investigated using in vitro models. However, the investigation of hypoxia in cellular pathways is complex with physical hypoxia because HIF-1α (factor induced by hypoxia) has a short half-life. We had set up an innovative and original method of induction of hypoxic stress by hydralazine that was more reproducible, which allowed us to study its impact on an in vitro BBB model. Our results showed that hydralazine, a mimetic agent of the hypoxia pathway, had the same effect as physical hypoxia, with few cytotoxicity effects on our cells. Hypoxic stress led to an increase of BBB permeability which corresponded to an opening of our BBB model. Study of tight junction proteins revealed that this hypoxic stress decreased ZO-1 but not occludin expression. In contrast, cells established a defence mechanism by increasing expression and activity of their efflux transporters (Pgp and MRP-1). This induction method of hypoxic stress by hydralazine is simple, reproducible, controllable and suitable to understand the cellular and molecular mechanisms involved by hypoxia on the BBB.
authors.affiliation: Université de Lyon, UJM-Saint-Etienne, SNA-EPIS, EA4607, F-42023, Saint-Etienne, France.|Université de Lyon, UJM-Saint-Etienne, INSERM, SAINBIOSE U1089 Team DVH, F-42023, Saint-Etienne, France.
authors.forename: Morgane
authors.initials: M
authors.lastname: Chatard
authors.affiliation: Université de Lyon, UJM-Saint-Etienne, INSERM, SAINBIOSE U1089 Team DVH, F-42023, Saint-Etienne, France.
authors.forename: Clémentine
authors.initials: C
authors.lastname: Puech
authors.affiliation: Université de Lyon, UJM-Saint-Etienne, SNA-EPIS, EA4607, F-42023, Saint-Etienne, France.
authors.forename: Frederic
authors.initials: F
authors.lastname: Roche
authors.affiliation: Université de Lyon, UJM-Saint-Etienne, INSERM, SAINBIOSE U1089 Team DVH, F-42023, Saint-Etienne, France.
authors.forename: Nathalie
authors.initials: N
authors.lastname: Perek
mesh_terms: D000818:Animals; D001692:Biological Transport; D015415:Biomarkers; D001812:Blood-Brain Barrier / Q000187:drug effects* / Q000378:metabolism*; D002470:Cell Survival / Q000187:drug effects; D006830:Hydralazine / Q000494:pharmacology* / Q000633:toxicity; D000860:Hypoxia / Q000378:metabolism*; D051795:Hypoxia-Inducible Factor 1, alpha Subunit / Q000378:metabolism; D026901:Membrane Transport Proteins / Q000378:metabolism*; D053858:Metabolic Networks and Pathways; D018384:Oxidative Stress / Q000187:drug effects*; D010539:Permeability; D051381:Rats; D062725:Tight Junction Proteins / Q000378:metabolism
chemical_list: D015415:Biomarkers; D051795:Hypoxia-Inducible Factor 1, alpha Subunit; D026901:Membrane Transport Proteins; D062725:Tight Junction Proteins; D006830:Hydralazine