Corneal stroma microfibrils

Handle URI:
http://hdl.handle.net/10754/566090
Title:
Corneal stroma microfibrils
Authors:
Hanlon, Samuel D.; Behzad, Ali Reza; Sakai, Lynn Y.; Burns, Alan R.
Abstract:
Elastic tissue was first described well over a hundred years ago and has since been identified in nearly every part of the body. In this review, we examine elastic tissue in the corneal stroma with some mention of other ocular structures which have been more thoroughly described in the past. True elastic fibers consist of an elastin core surrounded by fibrillin microfibrils. However, the presence of elastin fibers is not a requirement and some elastic tissue is comprised of non-elastin-containing bundles of microfibrils. Fibers containing a higher relative amount of elastin are associated with greater elasticity and those without elastin, with structural support. Recently it has been shown that the microfibrils, not only serve mechanical roles, but are also involved in cell signaling through force transduction and the release of TGF-β. A well characterized example of elastin-free microfibril bundles (EFMBs) is found in the ciliary zonules which suspend the crystalline lens in the eye. Through contraction of the ciliary muscle they exert enough force to reshape the lens and thereby change its focal point. It is believed that the molecules comprising these fibers do not turn-over and yet retain their tensile strength for the life of the animal. The mechanical properties of the cornea (strength, elasticity, resiliency) would suggest that EFMBs are present there as well. However, many authors have reported that, although present during embryonic and early postnatal development, EFMBs are generally not present in adults. Serial-block-face imaging with a scanning electron microscope enabled 3D reconstruction of elements in murine corneas. Among these elements were found fibers that formed an extensive network throughout the cornea. In single sections these fibers appeared as electron dense patches. Transmission electron microscopy provided additional detail of these patches and showed them to be composed of fibrils (~10nm diameter). Immunogold evidence clearly identified these fibrils as fibrillin EFMBs and EFMBs were also observed with TEM (without immunogold) in adult mammals of several species. Evidence of the presence of EFMBs in adult corneas will hopefully pique an interest in further studies that will ultimately improve our understanding of the cornea's biomechanical properties and its capacity to repair.
KAUST Department:
Advanced Nanofabrication, Imaging and Characterization Core Lab
Publisher:
Elsevier BV
Journal:
Experimental Eye Research
Issue Date:
Mar-2015
DOI:
10.1016/j.exer.2015.01.014
PubMed ID:
25613072
PubMed Central ID:
PMC4379971
Type:
Article
ISSN:
00144835
Sponsors:
We thank Evelyn Brown for her excellent help in preparation of EM specimens, and Paul Harris, Paul Landry, Siri Magadi, Nancy Shenoi, and Ian Smith for segmentation and 3D image reconstruction. Research results reported from our laboratory were obtained from projects supported by NEI grants: EY17120, EY007551 and HL116524.
Appears in Collections:
Articles; Advanced Nanofabrication, Imaging and Characterization Core Lab

Full metadata record

DC FieldValue Language
dc.contributor.authorHanlon, Samuel D.en
dc.contributor.authorBehzad, Ali Rezaen
dc.contributor.authorSakai, Lynn Y.en
dc.contributor.authorBurns, Alan R.en
dc.date.accessioned2015-08-12T09:27:51Zen
dc.date.available2015-08-12T09:27:51Zen
dc.date.issued2015-03en
dc.identifier.issn00144835en
dc.identifier.pmid25613072en
dc.identifier.doi10.1016/j.exer.2015.01.014en
dc.identifier.urihttp://hdl.handle.net/10754/566090en
dc.description.abstractElastic tissue was first described well over a hundred years ago and has since been identified in nearly every part of the body. In this review, we examine elastic tissue in the corneal stroma with some mention of other ocular structures which have been more thoroughly described in the past. True elastic fibers consist of an elastin core surrounded by fibrillin microfibrils. However, the presence of elastin fibers is not a requirement and some elastic tissue is comprised of non-elastin-containing bundles of microfibrils. Fibers containing a higher relative amount of elastin are associated with greater elasticity and those without elastin, with structural support. Recently it has been shown that the microfibrils, not only serve mechanical roles, but are also involved in cell signaling through force transduction and the release of TGF-β. A well characterized example of elastin-free microfibril bundles (EFMBs) is found in the ciliary zonules which suspend the crystalline lens in the eye. Through contraction of the ciliary muscle they exert enough force to reshape the lens and thereby change its focal point. It is believed that the molecules comprising these fibers do not turn-over and yet retain their tensile strength for the life of the animal. The mechanical properties of the cornea (strength, elasticity, resiliency) would suggest that EFMBs are present there as well. However, many authors have reported that, although present during embryonic and early postnatal development, EFMBs are generally not present in adults. Serial-block-face imaging with a scanning electron microscope enabled 3D reconstruction of elements in murine corneas. Among these elements were found fibers that formed an extensive network throughout the cornea. In single sections these fibers appeared as electron dense patches. Transmission electron microscopy provided additional detail of these patches and showed them to be composed of fibrils (~10nm diameter). Immunogold evidence clearly identified these fibrils as fibrillin EFMBs and EFMBs were also observed with TEM (without immunogold) in adult mammals of several species. Evidence of the presence of EFMBs in adult corneas will hopefully pique an interest in further studies that will ultimately improve our understanding of the cornea's biomechanical properties and its capacity to repair.en
dc.description.sponsorshipWe thank Evelyn Brown for her excellent help in preparation of EM specimens, and Paul Harris, Paul Landry, Siri Magadi, Nancy Shenoi, and Ian Smith for segmentation and 3D image reconstruction. Research results reported from our laboratory were obtained from projects supported by NEI grants: EY17120, EY007551 and HL116524.en
dc.publisherElsevier BVen
dc.subjectCorneaen
dc.subjectElastic tissueen
dc.subjectFibrillinen
dc.subjectMicrofibrilsen
dc.subjectOxytalanen
dc.titleCorneal stroma microfibrilsen
dc.typeArticleen
dc.contributor.departmentAdvanced Nanofabrication, Imaging and Characterization Core Laben
dc.identifier.journalExperimental Eye Researchen
dc.identifier.pmcidPMC4379971en
dc.contributor.institutionCollege of Optometry, University of HoustonHouston, TX, United Statesen
dc.contributor.institutionShiners Hospital for Children and Department of Biochemistry and Molecular Biology, Oregon Health and Science UniversityPortland, OR, United Statesen
dc.contributor.institutionDepartment of Pediatrics, Baylor College of Medicine, 77030Houston, TX, United Statesen
kaust.authorBehzad, Ali Rezaen

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