Ubiquitin carboxyl-terminal esterase L1 promotes proliferation of human choroidal and retinal endothelial cells.
OBJECTIVE
We aimed: (1) to establish endothelial expression of ubiquitin carboxyl-terminal esterase L1 (UCHL1) in human choroid and retina and; (2) to investigate a role for UCHL1 in basic processes involved in intraocular neovascularization.


METHODS
Controlled translational experimental study.


METHODS
Ethanol-fixed human choroid and retina (n = 3 eyes) were indirectly immunostained with rabbit anti-human UCHL1 antibody. Endothelial proliferation and migration assays were performed using cultured human choroidal and retinal endothelial cells (n = 6 isolates/assay). Cells were transfected with UCHL1-targeted or non-targeted small interfering (si)RNA and a commercially available transfection system, and used 48 hours later in experiments. Cell proliferation was evaluated using an assay in which cellular DNA was fluorescently tagged for quantification by microplate reader. Cell migration was examined in an assay that involved counting the number of endothelial cells moving across a perforated membrane. Transcript silencing was verified by Western blot for all assays.


RESULTS
Immunohistochemistry confirmed expression of UCHL1 by endothelium in human choroid and retina in vivo. UCHL1-specific knockdown resulted in significantly less proliferation (p < 0.0001) for 3 human choroidal endothelial isolates and 3 human retinal endothelial isolates, and significantly less migration (p ≤ 0.016) for 2 of 3 human choroidal endothelial isolates and 1 of 3 human retinal endothelial isolates.


CONCLUSIONS
Our results suggest that UCHL1 may be involved in choroidal and retinal endothelial proliferation in most persons, and endothelial migration in some persons. UCHL1 may be a suitable target for a new treatment of intraocular neovascularisation.
Casey Eye Institute, Oregon Health & Science University, Portland, OR, USA.
Yuzhen
Y
Pan
Casey Eye Institute, Oregon Health & Science University, Portland, OR, USA ; Eye & Vision Health, Flinders University, Adelaide, Australia.
Binoy
B
Appukuttan
Casey Eye Institute, Oregon Health & Science University, Portland, OR, USA.
Kathleen
K
Mohs
Eye & Vision Health, Flinders University, Adelaide, Australia.
Liam M
LM
Ashander
Casey Eye Institute, Oregon Health & Science University, Portland, OR, USA ; Eye & Vision Health, Flinders University, Adelaide, Australia.
Justine R
JR
Smith
D002102:Cadaver; D002465:Cell Movement / Q000502:physiology; D049109:Cell Proliferation / Q000502:physiology; D002829:Choroid / Q000378:metabolism*; D042783:Endothelial Cells / Q000201:enzymology*; D006801:Humans; D007150:Immunohistochemistry; D009389:Neovascularization, Pathologic / Q000503:physiopathology*; D012160:Retina / Q000201:enzymology*; D043222:Ubiquitin Thiolesterase / Q000378:metabolism / Q000502:physiology*; D042461:Vascular Endothelial Growth Factor A / Q000037:antagonists & inhibitors
C482860:UCHL1 protein, human; D042461:Vascular Endothelial Growth Factor A; D043222:Ubiquitin Thiolesterase
Choroid; Endothelial Cell; Retina; UCHL1