In vitro and in vivo inhibition of proangiogenic retinal phenotype by an antisense oligonucleotide downregulating uPAR expression

Neoan­gio­gen­e­sis is the main path­o­genic event in­volved in a va­ri­ety of reti­nal dis­eases. It has been re­cently demon­strated that in­hibit­ing the uroki­nase-type plas­mino­gen ac­ti­va­tor re­cep­tor (uPAR) re­sults in re­duced an­gio­gen­e­sis in a mouse model of oxy­gen-in­duced retinopa­thy (OIR), es­tab­lish­ing uPAR as a ther­a­peu­tic tar­get in pro­lif­er­a­tive retinopathies. Here, we eval­u­ated in cul­tured hu­man reti­nal en­dothe­lial cells (HRECs) and in OIR mice the po­ten­tial of a spe­cific an­ti­sense oligodeoxyri­bonu­cleotide (ASO) in block­ing the syn­the­sis of uPAR and in pro­vid­ing an­tian­gio­genic ef­fects. uPAR ex­pres­sion in HRECs was in­hib­ited by lipo­fec­tion with the phos­pho­ro­tioated 5′-CG­GCGGGT­GAC­C­CAT­GTG-3′ ASO-uPAR, com­ple­men­tary to the ini­tial trans­la­tion site of uPAR mRNA. In­hi­bi­tion of uPAR ex­pres­sion via ASO-uPAR was eval­u­ated in HRECs by an­a­lyz­ing VEGF-in­duced tube for­ma­tion and mi­gra­tion. In ad­di­tion, the well-es­tab­lished and re­pro­ducible murine OIR model was used to in­duce reti­nal neo­vas­cu­lar­iza­tion in vivo. OIR mice were in­jected in­traperi­toneally with ASO-uPAR and retinopa­thy was eval­u­ated con­sid­er­ing the ex­tent of the avas­cu­lar area in the cen­tral retina and neo­vas­cu­lar tuft for­ma­tion. The ASO-uPAR specif­i­cally de­creased uPAR mRNA and pro­tein lev­els in HRECs and mit­i­gated VEGF-in­duced tube for­ma­tion and cell mi­gra­tion. Note­wor­thy, in OIR mice ASO-uPAR ad­min­is­tra­tion re­duced both the avas­cu­lar area and the for­ma­tion of neo­vas­cu­lar tufts. In con­clu­sion, al­though the ex­trap­o­la­tion of these ex­per­i­men­tal find­ings to the clinic is not straight­for­ward, ASO-uPAR may be con­sid­ered a po­ten­tial ther­a­peu­tic tool for treat­ment of pro­lif­er­a­tive reti­nal dis­eases.