TY - JOUR
T1 - The spatial organization of apical junctional complex-associated proteins in feline and human corneal endothelium
AU - Petroll, Walter M
AU - Hsu, Joseph K W
AU - Bean, Jacquelyn
AU - Cavanagh, Harrison D
AU - Jester, James V.
N1 - Funding Information:
Supported in part by NIH EY11235, Senior Scientist Awards (JVJ, HDC), Manpower Award (WMP) and unrestricted grant from Research to Prevent Blindness, Inc., New York, NY.
PY - 1999/1
Y1 - 1999/1
N2 - Purpose. Previous studies suggest that proteins associated with the apical junctional complex (AJC) play essential roles in the development, maintenance and regulation of barrier function in transport epithelium and vascular endothelium. The goal of this study is to identify and determine the spatial organization of several major AJC-associated proteins in normal human and feline corneal endothelium. Methods. Fresh corneal tissue was obtained from 4 recipient buttons removed during penetrating keratoplasty (two from keratoconus patients, and two from patients with post-traumatic stromal scarring) as well as from 16 cat eyes. En bloc double- and triple-labeling of corneas was performed using phalloidin, and mouse, rat or rabbit antibodies to ZO-1, occludin, pan-cadherin, α-catenin, β-catenin and plakoglobin (γ-catenin). The 3-D localization of the proteins was then determined in situ using laser confocal microscopy. Results. Similar staining patterns were obtained for the corneal endothelium of normal cat corneas and fresh human buttons. Apically, f-actin was arranged into dense peripheral bands (DPB) in individual cells that were separated from those in adjacent cells. Diffuse phalloidin staining also extended from the DPB into the cytoplasm apically. Although weaker, phalloidin staining also appeared to be associated with the basolateral cell borders. The adherens junction protein, cadherin, formed a thin pericellular band at the apical cell junctions between the DPB. In addition, cadherin staining also appeared to extend along the basolateral cell borders in a convoluted pattern. Staining for α-catenin, β-catenin and plakoglobin each showed a nearly identical organization as cadherin. ZO-1 formed a single apical band that was localized between the DPB; however, no basolateral ZO-1 staining was detected. Interestingly, the distribution of ZO-1 was discontinuous around the cell, with the largest gaps occurring at the Y-junctions between adjacent endothelial cells. Positive staining for occludin was not detected in either human or feline corneal endothelium. Conclusions. The composition and organization of the AJC of corneal endothelium appears to be different from that of classical transport epithelia; these findings may be related to functional differences between these two cell types.
AB - Purpose. Previous studies suggest that proteins associated with the apical junctional complex (AJC) play essential roles in the development, maintenance and regulation of barrier function in transport epithelium and vascular endothelium. The goal of this study is to identify and determine the spatial organization of several major AJC-associated proteins in normal human and feline corneal endothelium. Methods. Fresh corneal tissue was obtained from 4 recipient buttons removed during penetrating keratoplasty (two from keratoconus patients, and two from patients with post-traumatic stromal scarring) as well as from 16 cat eyes. En bloc double- and triple-labeling of corneas was performed using phalloidin, and mouse, rat or rabbit antibodies to ZO-1, occludin, pan-cadherin, α-catenin, β-catenin and plakoglobin (γ-catenin). The 3-D localization of the proteins was then determined in situ using laser confocal microscopy. Results. Similar staining patterns were obtained for the corneal endothelium of normal cat corneas and fresh human buttons. Apically, f-actin was arranged into dense peripheral bands (DPB) in individual cells that were separated from those in adjacent cells. Diffuse phalloidin staining also extended from the DPB into the cytoplasm apically. Although weaker, phalloidin staining also appeared to be associated with the basolateral cell borders. The adherens junction protein, cadherin, formed a thin pericellular band at the apical cell junctions between the DPB. In addition, cadherin staining also appeared to extend along the basolateral cell borders in a convoluted pattern. Staining for α-catenin, β-catenin and plakoglobin each showed a nearly identical organization as cadherin. ZO-1 formed a single apical band that was localized between the DPB; however, no basolateral ZO-1 staining was detected. Interestingly, the distribution of ZO-1 was discontinuous around the cell, with the largest gaps occurring at the Y-junctions between adjacent endothelial cells. Positive staining for occludin was not detected in either human or feline corneal endothelium. Conclusions. The composition and organization of the AJC of corneal endothelium appears to be different from that of classical transport epithelia; these findings may be related to functional differences between these two cell types.
KW - Adherens junction
KW - Confocal microscopy
KW - Corneal endothelium
KW - F-actin
KW - Tight junctions
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U2 - 10.1076/ceyr.18.1.10.5392
DO - 10.1076/ceyr.18.1.10.5392
M3 - Article
C2 - 10075198
AN - SCOPUS:0032943072
SN - 0271-3683
VL - 18
SP - 10
EP - 19
JO - Current Eye Research
JF - Current Eye Research
IS - 1
ER -