1. Academic Validation
  2. 2-Chlorohexadecanoic acid induces ER stress and mitochondrial dysfunction in brain microvascular endothelial cells

2-Chlorohexadecanoic acid induces ER stress and mitochondrial dysfunction in brain microvascular endothelial cells

  • Redox Biol. 2018 May;15:441-451. doi: 10.1016/j.redox.2018.01.003.
Eva Bernhart 1 Nora Kogelnik 2 Jürgen Prasch 3 Benjamin Gottschalk 4 Madeleine Goeritzer 5 Maria Rosa Depaoli 6 Helga Reicher 7 Christoph Nusshold 8 Ioanna Plastira 9 Astrid Hammer 10 Günter Fauler 11 Roland Malli 12 Wolfgang F Graier 13 Ernst Malle 14 Wolfgang Sattler 15
Affiliations

Affiliations

  • 1 Gottfried Schatz Research Center for Signaling, Metabolism and Aging, Molecular Biology and Biochemistry, Medical University of Graz, Austria. Electronic address: [email protected].
  • 2 Gottfried Schatz Research Center for Signaling, Metabolism and Aging, Molecular Biology and Biochemistry, Medical University of Graz, Austria. Electronic address: [email protected].
  • 3 Gottfried Schatz Research Center for Signaling, Metabolism and Aging, Molecular Biology and Biochemistry, Medical University of Graz, Austria. Electronic address: [email protected].
  • 4 Gottfried Schatz Research Center for Signaling, Metabolism and Aging, Molecular Biology and Biochemistry, Medical University of Graz, Austria. Electronic address: [email protected].
  • 5 Gottfried Schatz Research Center for Signaling, Metabolism and Aging, Molecular Biology and Biochemistry, Medical University of Graz, Austria; BioTechMed Graz, Austria. Electronic address: [email protected].
  • 6 Gottfried Schatz Research Center for Signaling, Metabolism and Aging, Molecular Biology and Biochemistry, Medical University of Graz, Austria. Electronic address: [email protected].
  • 7 Gottfried Schatz Research Center for Signaling, Metabolism and Aging, Molecular Biology and Biochemistry, Medical University of Graz, Austria. Electronic address: [email protected].
  • 8 Institute of Physiological Chemistry, Medical University of Graz, Austria. Electronic address: [email protected].
  • 9 Gottfried Schatz Research Center for Signaling, Metabolism and Aging, Molecular Biology and Biochemistry, Medical University of Graz, Austria. Electronic address: [email protected].
  • 10 Gottfried Schatz Research Center for Signaling, Metabolism and Aging, Cell Biology, Histology and Embryology, Medical University of Graz, Austria. Electronic address: [email protected].
  • 11 Clinical Institute of Medical and Chemical Laboratory Diagnostics, Medical University of Graz, Austria. Electronic address: [email protected].
  • 12 Gottfried Schatz Research Center for Signaling, Metabolism and Aging, Molecular Biology and Biochemistry, Medical University of Graz, Austria; BioTechMed Graz, Austria. Electronic address: [email protected].
  • 13 Gottfried Schatz Research Center for Signaling, Metabolism and Aging, Molecular Biology and Biochemistry, Medical University of Graz, Austria; BioTechMed Graz, Austria. Electronic address: [email protected].
  • 14 Gottfried Schatz Research Center for Signaling, Metabolism and Aging, Molecular Biology and Biochemistry, Medical University of Graz, Austria. Electronic address: [email protected].
  • 15 Gottfried Schatz Research Center for Signaling, Metabolism and Aging, Molecular Biology and Biochemistry, Medical University of Graz, Austria; BioTechMed Graz, Austria. Electronic address: [email protected].
Abstract

Peripheral leukocytes induce blood-brain barrier (BBB) dysfunction through the release of cytotoxic mediators. These include hypochlorous acid (HOCl) that is formed via the myeloperoxidase-H2O2-chloride system of activated phagocytes. HOCl targets the endogenous pool of ether Phospholipids (plasmalogens) generating chlorinated inflammatory mediators like e.g. 2-chlorohexadecanal and its conversion product 2-chlorohexadecanoic acid (2-ClHA). In the cerebrovasculature these compounds inflict damage to brain microvascular endothelial cells (BMVEC) that form the morphological basis of the BBB. To follow subcellular trafficking of 2-ClHA we synthesized a 'clickable' alkyne derivative (2-ClHyA) that phenocopied the biological activity of the parent compound. Confocal and superresolution structured illumination microscopy revealed accumulation of 2-ClHyA in the endoplasmic reticulum (ER) and mitochondria of human BMVEC (hCMEC/D3 cell line). 2-ClHA and its alkyne analogue interfered with protein palmitoylation, induced ER-stress markers, reduced the ER ATP content, and activated transcription and secretion of interleukin (IL)-6 as well as IL-8. 2-ClHA disrupted the mitochondrial membrane potential and induced procaspase-3 and PARP cleavage. The protein kinase R-like ER kinase (PERK) inhibitor GSK2606414 suppressed 2-ClHA-mediated activating transcription factor 4 synthesis and IL-6/8 secretion, but showed no effect on endothelial barrier dysfunction and cleavage of procaspase-3. Our data indicate that 2-ClHA induces potent lipotoxic responses in brain endothelial cells and could have implications in inflammation-induced BBB dysfunction.

Keywords

Apoptosis; Blood-brain barrier; Lipotoxicity; Myeloperoxidase; Neuroinflammation; Structured illumination microscopy.

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