Front Neurol. 2019; 10: 533. Published online 2019 May 29. doi: 10.3389/fneur.2019.00533
Cecilia Rönnbäck and Elisabeth Hansson (Department of Ophthalmology, Rigshospitalet, Glostrup, Denmark; Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark; Department of Clinical Neuroscience, Institute of Neuroscience and Physiology, The Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden)
Edited by: Kempuraj Duraisamy, University of Missouri, United States
Reviewed by: Damir Janigro, Case Western Reserve University, United States; Manuel Antonio Riquelme, The University of Texas Health Science Center at San Antonio, United States
This article was submitted to Neurodegeneration, a section of the journal Frontiers in Neurology
Systemic low-grade inflammation can be initiated in vivo after traumatic injury or in chronic diseases such as neurodegenerative, metabolic, and autoimmune diseases. Inducers of inflammation trigger production of inflammatory mediators, which alter the functionality of tissues and organs and leads to harmful induction of different barrier systems in the body, where the blood-brain barrier, the blood-retinal barrier, blood-nerve barrier, blood-lymph barrier and the blood-cerebrospinal fluid barrier play major roles. The different barriers are unique but structured in a similar way. They are equipped with sophisticated junctional complexes where different connexins, protein subunits of gap junction channels and hemichannels, constitute important partners. The cells involved in the various barriers are coupled in networks, are excitable but do not express action potentials and may be targets for inflammation leading to changes in several biochemical cellular parameters. During any type of inflammation barrier break-down is observed where any form of injury can start with low-grade inflammation and may lead to systemic inflammation.
Keywords: blood-brain barrier, blood-retinal barrier, blood-nerve barrier, blood-lymph barrier, blood-cerebrospinal fluid barrier, low-grade inflammation, systemic inflammation