title: The Outflow Pathway: A Tissue With Morphological and Functional Unity.
abstract: The trabecular meshwork (TM) plays an important role in high-tension glaucomas. Indeed, the TM is a true organ, through which the aqueous humor flows from the anterior chamber to Schlemm's canal (SC). Until recently, the TM, which is constituted by endothelial-like cells, was described as a kind of passive filter. In reality, it is much more. The cells delineating the structures of the collagen framework of the TM are endowed with a cytoskeleton, and are thus able to change their shape. These cells also have the ability to secrete the extracellular matrix, which expresses proteins and cytokines, and are capable of phagocytosis and autophagy. The cytoskeleton is attached to the nuclear membrane and can, in millionths of a second, send signals to the nucleus in order to alter the expression of genes in an attempt to adapt to biomechanical insult. Oxidative stress, as happens in aging, has a deleterious effect on the TM, leading eventually to cell decay, tissue malfunction, subclinical inflammation, changes in the extracellular matrix and cytoskeleton, altered motility, reduced outflow facility, and (ultimately) increased IOP. TM failure is the most relevant factor in the cascade of events triggering apoptosis in the inner retinal layers, including ganglion cells. J. Cell. Physiol. 231: 1876-1893, 2016. © 2016 Wiley Periodicals, Inc.
authors.affiliation: Department of Neuroscience and Sense Organs, Ophthalmology Unit, IRCCS San Martino University Hospital, San Martino Hospital, Genoa, Italy.
authors.forename: Sergio Claudio
authors.initials: SC
authors.lastname: Saccà
authors.affiliation: Department of Biological, Biotechnological and Translational Sciences, Ophthalmology Unit, University of Parma, Parma, Italy.
authors.forename: Stefano
authors.initials: S
authors.lastname: Gandolfi
authors.affiliation: Department of Neuroscience and Sense Organs, Eye Clinic, University of Genoa, Genoa, Italy.
authors.forename: Alessandro
authors.initials: A
authors.lastname: Bagnis
authors.affiliation: Department of Clinical Science and Translational Medicine, University Tor Vergata, Rome, Italy.
authors.forename: Gianluca
authors.initials: G
authors.lastname: Manni
authors.affiliation: Department of Experimental Medicine, Section of Biochemistry and Center of Excellence for Biomedical Research, University of Genoa, Genoa, Italy.
authors.forename: Gianluca
authors.initials: G
authors.lastname: Damonte
authors.affiliation: Department of Neuroscience and Sense Organs, Eye Clinic, University of Genoa, Genoa, Italy.
authors.forename: Carlo Enrico
authors.initials: CE
authors.lastname: Traverso
authors.affiliation: Department of Health Sciences, Mutagenesis Unit, IRCCS San Martino University Hospital, IST National Institute for Cancer Research, University of Genoa, Genoa, Italy.
authors.forename: Alberto
authors.initials: A
authors.lastname: Izzotti
mesh_terms: D000818:Animals; D001082:Aqueous Humor / Q000378:metabolism*; D003599:Cytoskeleton / Q000378:metabolism* / Q000473:pathology; D005109:Extracellular Matrix / Q000378:metabolism / Q000473:pathology; D005901:Glaucoma / Q000175:diagnosis / Q000378:metabolism*; D006801:Humans; D018384:Oxidative Stress / Q000502:physiology*; D014129:Trabecular Meshwork / Q000378:metabolism* / Q000473:pathology