Go to JCI Insight
  • About
  • Editors
  • Consulting Editors
  • For authors
  • Alerts
  • Advertising/recruitment
  • Subscribe
  • Contact
  • Current Issue
  • Past Issues
  • By specialty
    • COVID-19
    • Cardiology
    • Gastroenterology
    • Immunology
    • Metabolism
    • Nephrology
    • Neuroscience
    • Oncology
    • Pulmonology
    • Vascular biology
    • All ...
  • Videos
    • Conversations with Giants in Medicine
    • Author's Takes
  • Reviews
    • View all reviews ...
    • 100th Anniversary of Insulin's Discovery (Jan 2021)
    • Hypoxia-inducible factors in disease pathophysiology and therapeutics (Oct 2020)
    • Latency in Infectious Disease (Jul 2020)
    • Immunotherapy in Hematological Cancers (Apr 2020)
    • Big Data's Future in Medicine (Feb 2020)
    • Mechanisms Underlying the Metabolic Syndrome (Oct 2019)
    • Reparative Immunology (Jul 2019)
    • View all review series ...
  • Viewpoint
  • Collections
    • Recently published
    • In-Press Preview
    • Commentaries
    • Concise Communication
    • Editorials
    • Viewpoint
    • Top read articles
  • Clinical Medicine
  • JCI This Month
    • Current issue
    • Past issues

  • Current issue
  • Past issues
  • Specialties
  • Reviews
  • Review series
  • Conversations with Giants in Medicine
  • Author's Takes
  • Recently published
  • In-Press Preview
  • Commentaries
  • Concise Communication
  • Editorials
  • Viewpoint
  • Top read articles
  • About
  • Editors
  • Consulting Editors
  • For authors
  • Alerts
  • Advertising/recruitment
  • Subscribe
  • Contact
Astrocytic tight junctions control inflammatory CNS lesion pathogenesis
Sam Horng, … , Candice Chapouly, Gareth R. John
Sam Horng, … , Candice Chapouly, Gareth R. John
Published July 24, 2017
Citation Information: J Clin Invest. 2017;127(8):3136-3151. https://doi.org/10.1172/JCI91301.
View: Text | PDF
Research Article Immunology Neuroscience

Astrocytic tight junctions control inflammatory CNS lesion pathogenesis

  • Text
  • PDF
Abstract

Lesions and neurologic disability in inflammatory CNS diseases such as multiple sclerosis (MS) result from the translocation of leukocytes and humoral factors from the vasculature, first across the endothelial blood-brain barrier (BBB) and then across the astrocytic glia limitans (GL). Factors secreted by reactive astrocytes open the BBB by disrupting endothelial tight junctions (TJs), but the mechanisms that control access across the GL are unknown. Here, we report that in inflammatory lesions, a second barrier composed of reactive astrocyte TJs of claudin 1 (CLDN1), CLDN4, and junctional adhesion molecule A (JAM-A) subunits is induced at the GL. In a human coculture model, CLDN4-deficient astrocytes were unable to control lymphocyte segregation. In models of CNS inflammation and MS, mice with astrocyte-specific Cldn4 deletion displayed exacerbated leukocyte and humoral infiltration, neuropathology, motor disability, and mortality. These findings identify a second inducible barrier to CNS entry at the GL. This barrier may be therapeutically targetable in inflammatory CNS disease.

Authors

Sam Horng, Anthony Therattil, Sarah Moyon, Alexandra Gordon, Karla Kim, Azeb Tadesse Argaw, Yuko Hara, John N. Mariani, Setsu Sawai, Per Flodby, Edward D. Crandall, Zea Borok, Michael V. Sofroniew, Candice Chapouly, Gareth R. John

×

Figure 7

Astrocytic CLDN4 is degraded in EAE lesions and in coculture with activated CD3+ lymphocytes in vitro.

Options: View larger image (or click on image) Download as PowerPoint
Astrocytic CLDN4 is degraded in EAE lesions and in coculture with activa...
(A and B) Immunoblotting (A) and densitometric quantification (B) of spinal cord lysates from C57BL/6 mice with EAE (score 2–3, from 18–21 days) and age- and sex-matched controls demonstrate induction of CLDN1, CLND4, and JAM-A in EAE (A and B, upper panel), along with degradation products of CLDN1 and CLDN4 (14 kDa and 18 kDa), but not JAM-A (A and B, lower panel). (C and D) Immunoblotting and densitometry of cocultures of reactive human astrocytes (IL-1β–treated followed by washout) with activated CD3+ lymphocytes. Coculture leads to degradation of astrocytic CLDN4 by 24 hours, and CLDN4 degradation is blocked by specific protease inhibitors, including the serine protease inhibitor aprotinin, and by MMP inhibitor-2. In contrast, degradation is not blocked by the cysteine protease inhibitor E-64, or the aspartic protease inhibitor pepstatin. These studies collectively suggest combinations of kallikrein and urokinase (substrates of aprotinin) and MMP-1, -3, -7, and -9 (substrates of MMP inhibitor-2) as potentially responsible for CLDN1 and CLDN4 digestion (see also Supplemental Figure 5, A–C). (E–G) Human astrocytes were pretreated for 24 hours with 10 mg/ml IL-1β, then washed and cultured alone or with activated CD3+ cells for 72 hours. Supernatant and cell lysates of isolated astrocytes or leukocytes were then harvested and applied to protease arrays (3 biological replicates of each condition) (E and F). Astrocyte lysates from coculture with CD3+ cells showed upregulation of kallikrein 7, MMP-2, -7, -8, and -9, and CD10 compared with lysate from monoculture (n = 3 each group, 2-tailed t test, P < 0.05). (E and G) CD3+ cell lysates from coculture demonstrated strongest expression of cathepsins A and D, DDPIV, MMP-8, and uPA. See also Supplemental Figure 5, D and E. Data in A–G are representative of findings from 3 or more biological replicates. *P < 0.05, **P < 0.01.
Follow JCI:
Copyright © 2021 American Society for Clinical Investigation
ISSN: 0021-9738 (print), 1558-8238 (online)

Sign up for email alerts