Investigative ophthalmology & visual science
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Invest. Ophthalmol. Vis. Sci. · Jun 2003
Corneal innervation and morphology in primary Sjögren's syndrome.
To analyze the in vivo morphology of the different corneal sublayers and corneal nerves in primary Sjögren's syndrome (SS). ⋯ In SS, the corneal surface epithelium was irregular and patchy. Anterior keratocytes frequently showed morphologic features of activation. The subbasal nerve fiber bundles revealed abnormal morphology, and the central corneal thickness was reduced by stromal thinning. The findings confirm epithelial, stromal, and neural abnormalities in the corneas of patients with SS.
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Invest. Ophthalmol. Vis. Sci. · May 2003
Response of lens epithelial cells to injury: role of lumican in epithelial-mesenchymal transition.
Lens epithelial cells (LECs) undergo epithelial-mesenchcymal transition (EMT) after injury and transform into myofibroblasts positive for alpha-smooth muscle actin (alphaSMA), an established marker of this process. Lumican is a keratan sulfate proteoglycan core protein. This study was conducted to examine whether human and mouse LECs express lumican after injury. To determine whether lumican may modulate EMT of LECs in response to injury or to exposure to transforming growth factor-beta2 (TGFbeta2), alphaSMA expression by the LECs was examined in lumican (Lum)-knockout mice in vivo and in organ culture. ⋯ Human capsular opacification contains lumican, and mouse LECs upregulate lumican and alphaSMA in response to injury. Loss of lumican perturbs EMT of mouse LECs.
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Invest. Ophthalmol. Vis. Sci. · May 2003
Connective tissue growth factor expression and action in human corneal fibroblast cultures and rat corneas after photorefractive keratectomy.
Connective tissue growth factor (CTGF) has been linked to fibrosis in several tissues. In this study, the interactions between CTGF and transforming growth factor (TGF)-beta were assessed in human corneal fibroblasts, and the levels and location of CTGF protein and mRNA were measured during healing of excimer laser ablation wounds in rat corneas. ⋯ These data demonstrate that CTGF is expressed by corneal cells after stimulation by TGF-beta, that CTGF expression increases significantly during corneal wound healing, and that CTGF mediates the effects of TGF-beta induction of collagen synthesis by corneal fibroblasts. These data support the hypothesis that CTGF promotes corneal scar formation and imply that regulating CTGF synthesis and action may be an important goal for reducing corneal scarring.
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To define the normal and variant venous anatomy in the human orbit. ⋯ The venous anatomy of the orbit demonstrates considerable variability. Some of these variations may have implications in surgical management and natural history of ophthalmic conditions, such as carotid-cavernous sinus fistula (CCSF).
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Invest. Ophthalmol. Vis. Sci. · Oct 2002
Brain-derived neurotrophic factor prevents axotomized retinal ganglion cell death through MAPK and PI3K signaling pathways.
Brain-derived neurotrophic factor (BDNF) has a potential neuroprotective effect on axotomized retinal ganglion cells (RGCs); however, the mechanism, in regard to intracellular signaling, of BDNF-induced neuroprotection of RGCs is largely unknown. Intracellular signaling was investigated, by using axotomized RGCs and the relative contribution of the two major downstream signaling routes of TrkB determined--that is, mitogen-activated protein kinase (MAPK) and phosphatidylinositol 3 kinase (PI3K)-Akt routes, mediated by BDNF. ⋯ BDNF-mediated signaling involves activation of both MAPK and Akt on the axotomized adult rat retina, and the collaboration of both MAPK and PI3K-Akt pathways seems to be necessary in neuroprotective signaling in axotomized RGCs.