Evaluating UBX1967 in Mouse OIR Model

Example 6

The efficacy of model compound UBX1967 was studied in the mouse oxygen-induced retinopathy (OIR) model, which provides an in vivo model of retinopathy of prematurity (ROP) and diabetic retinopathy.

C57Bl/6 mouse pups and their CD1 foster mothers were exposed to a high oxygen environment (75% 02) from postnatal day 7 (P7) to P12. At P12, animals were injected intravitreally with 1 μl test compound (200, 20, or 2 uM) formulated in 1% DMSO, 10% Tween-80, 20% PEG-400, and returned to room air until P17. Eyes were enucleated at P17 and retinas dissected for either vascular staining or qRT-PCR. To determine avascular or neovascular area, retinas were flatmounted, and stained with isolectin B4 (IB4) diluted 1:100 in 1 mM CaCl₂. For quantitative measurement of senesecence markers (e.g., Cdkn2a, Cdkn1a, 116, Vegfa), qPCR was performed. RNA was isolated and cDNA was generated by reverse-transcription, which was used for qRT-PCR of the selected transcripts.

FIGS. 9A and 9B show that intravitreal (IVT) administration UBX1967 resulted in statistically significant improvement in the degree of neovascularization and vaso-obliteration at all dose levels.

FIGS. 10A and 10B show the relative abundance of several transcripts associated with senescence (p16, pai1) and human disease (vegf). Treatment with UBX1967 resulted in a 58%, 35%, and 24% reduction in p16, pai1, and vegf, respectively. Senescence-associated β-galactosidase (SA-BGal) activity was reduced by 17% after administration of UBX1967.

These results show that a single ocular injection of UBX1967 can functionally inhibit pathogenic angiogenesis and promote vascular repair in this key OIR disease model. We believe that efficacy of UBX1967 in the OIR model is due to elimination of senescent cells and accompanying SASP that propagates senescence in retinal cells and promotes neovascularization of retinal vessels.