title: PDCD10 (CCM3) regulates brain endothelial barrier integrity in cerebral cavernous malformation type 3: role of CCM3-ERK1/2-cortactin cross-talk.
abstract: Impairment of brain endothelial barrier integrity is critical for cerebral cavernous malformation (CCM) lesion development. The current study investigates changes in tight junction (TJ) complex organization when PDCD10 (CCM3) is mutated/depleted in human brain endothelial cells. Analysis of lesions with CCM3 mutation and brain endothelial cells transfected with CCM3 siRNA (CCM3-knockdown) showed little or no increase in TJ transmembrane and scaffolding proteins mRNA expression, but proteins levels were generally decreased. CCM3-knockdown cells had a redistribution of claudin-5 and occludin from the membrane to the cytosol with no alterations in protein turnover but with diminished protein-protein interactions with ZO-1 and ZO-1 interaction with the actin cytoskeleton. The most profound effect of CCM3 mutation/depletion was on an actin-binding protein, cortactin. CCM3 depletion caused cortactin Ser-phosphorylation, dissociation from ZO-1 and actin, redistribution to the cytosol and degradation. This affected cortical actin ring organization, TJ complex stability and consequently barrier integrity, with constant hyperpermeability to inulin. A potential link between CCM3 depletion and altered cortactin was tonic activation of MAP kinase ERK1/2. ERK1/2 inhibition increased cortactin expression and incorporation into the TJ complex and improved barrier integrity. This study highlights the potential role of CCM3 in regulating TJ complex organization and brain endothelial barrier permeability.
authors.affiliation: Department of Pathology, University of Michigan, Medical School, 7520A MSRB I, 1150 W Medical Center Dr, Ann Arbor, MI, 48109-5602, USA.
authors.forename: Svetlana M
authors.initials: SM
authors.lastname: Stamatovic
authors.affiliation: Department of Pathology, University of Michigan, Medical School, 7520A MSRB I, 1150 W Medical Center Dr, Ann Arbor, MI, 48109-5602, USA.
authors.forename: Nikola
authors.initials: N
authors.lastname: Sladojevic
authors.affiliation: Department of Neurosurgery, University of Michigan, Medical School, R5018 BSRB, 109 Zina Pitcher Place, Ann Arbor, MI, 48109-2200, USA.|Department of Molecular & Integrative Physiology, University of Michigan, Medical School, R5018 BSRB, 109 Zina Pitcher Place, Ann Arbor, MI, 48109-2200, USA.
authors.forename: Richard F
authors.initials: RF
authors.lastname: Keep
authors.affiliation: Department of Pathology, University of Michigan, Medical School, 7520A MSRB I, 1150 W Medical Center Dr, Ann Arbor, MI, 48109-5602, USA. anuskaa@med.umich.edu.|Department of Neurosurgery, University of Michigan, Medical School, R5018 BSRB, 109 Zina Pitcher Place, Ann Arbor, MI, 48109-2200, USA. anuskaa@med.umich.edu.
authors.forename: Anuska V
authors.initials: AV
authors.lastname: Andjelkovic
mesh_terms: D000199:Actins / Q000378:metabolism; D051017:Apoptosis Regulatory Proteins / Q000235:genetics / Q000378:metabolism*; D001812:Blood-Brain Barrier / Q000378:metabolism* / Q000473:pathology; D002199:Capillary Permeability / Q000502:physiology*; D002478:Cells, Cultured; D051356:Cortactin / Q000378:metabolism*; D003600:Cytosol / Q000378:metabolism / Q000473:pathology; D042783:Endothelial Cells / Q000378:metabolism / Q000473:pathology; D006801:Humans; D008607:Intellectual Disability / Q000378:metabolism* / Q000473:pathology; D020935:MAP Kinase Signaling System / Q000502:physiology*; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism*; D008844:Micrognathism / Q000378:metabolism* / Q000473:pathology; D046988:Proteasome Endopeptidase Complex / Q000378:metabolism; D011518:Proto-Oncogene Proteins / Q000235:genetics / Q000378:metabolism*; D012333:RNA, Messenger / Q000378:metabolism; D012272:Ribs / Q000002:abnormalities* / Q000378:metabolism / Q000473:pathology; D019108:Tight Junctions / Q000378:metabolism / Q000473:pathology; D062826:Zonula Occludens-1 Protein / Q000378:metabolism
chemical_list: D000199:Actins; D051017:Apoptosis Regulatory Proteins; C495868:CTTN protein, human; D051356:Cortactin; D008565:Membrane Proteins; C495390:PDCD10 protein, human; D011518:Proto-Oncogene Proteins; D012333:RNA, Messenger; C569042:TJP1 protein, human; D062826:Zonula Occludens-1 Protein; D046988:Proteasome Endopeptidase Complex
keywords: Brain endothelial barrier; CCM3; Cortactin; Permeability; Tight junction