Suppression of ICAM-1 in retinal and choroidal endothelial cells by plasmid small-interfering RNAs in vivo.
OBJECTIVE
Leukocytes play a critical role in ocular diseases such as uveitis, diabetic retinopathy, and choroidal neovascularization. Intercellular adhesion molecule (ICAM)-1 is essential for the migration of leukocytes. Control of ICAM-1 expression may lead to therapies for these diseases. Small-interfering ribonucleic acids (siRNAs) are efficient specific modulators of endogenous gene expression. The authors describe the application of siRNA to suppress ICAM-1 expression on the murine neurosensory retina or retinal pigment epithelial (RPE) cells using a hydrodynamics-based transfection technique (HT) and intravitreal injection (IV) in vivo.


METHODS
ICAM-1-specific plasmid siRNAs designed from the murine gene sequence were transfected into the retina using HT and IV in vivo. Green fluorescent protein (GFP) expression plasmid vector is used as a transfection marker in the retinal cells. ICAM-1 expression was analyzed by enzyme-linked immunosorbent assay and flow cytometry. ICAM-1 upregulation was induced by retinal laser photocoagulation and streptozotocin (STZ).


RESULTS
After the administration of GFP expression plasmid with HT and IV, histologic analysis showed GFP fluorescence in every layer of the murine retina. After photocoagulation, ICAM-1 expression in the neurosensory retina or RPE cells transferred with plasmid ICAM-1 siRNA was significantly decreased compared with cells that were not transfected or cells transferred with scrambled control siRNA. Plasmid siRNAs silenced ICAM-1 expression after STZ administration compared with control or naked siRNA injection.


CONCLUSIONS
SiRNA expression mediated by this plasmid causes efficient and specific downregulation of ICAM-1 expression, suggesting that it can be silenced by plasmid siRNA in murine retina in vivo. This technology may lead to novel concepts to reduce retinal neovascular disease by inhibiting leukocyte infiltration.
Hirano
Yoshio
Y
Department of Ophthalmology and Visual Science, Nagoya City University Graduate School of Medical Sciences, Nagoya, Japan. yossyeye@med.nagoya-cu.ac.jp
Sakurai
Eiji
E
Matsubara
Akihisa
A
Ogura
Yuichiro
Y
D000818:Animals; D002829:Choroid / Q000098:blood supply*; D003921:Diabetes Mellitus, Experimental / Q000378:metabolism*; D004730:Endothelium, Vascular / Q000378:metabolism*; D004797:Enzyme-Linked Immunosorbent Assay; D005434:Flow Cytometry; D005786:Gene Expression Regulation / Q000187:drug effects*; D005822:Genetic Vectors; D049452:Green Fluorescent Proteins / Q000378:metabolism; D018799:Intercellular Adhesion Molecule-1 / Q000235:genetics* / Q000378:metabolism; D017075:Laser Coagulation; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D009000:Monocytes / Q000502:physiology; D010957:Plasmids; D034741:RNA, Small Interfering / Q000494:pharmacology*; D012160:Retina / Q000378:metabolism; D012171:Retinal Vessels / Q000166:cytology*; D014162:Transfection
D034741:RNA, Small Interfering; D018799:Intercellular Adhesion Molecule-1; D049452:Green Fluorescent Proteins