Hannah Hu
Research Mentor: Diana Gallego Martinez
Mentor Department: Ophthalmology and Visual Science, Medicine
Author(s): Hannah Hu, Diana Gallego Martinez, Lev Prasov
Session: Session 3 (11:00 AM – 11:50 AM)
Presentation Type: Poster 32
Abstract
Singleton-Merten Syndrome (SGMRT) is caused by gain-of-function mutations in the innate immune sensor RIG-I (encoded by the Rigi gene), resulting in chronic overactivation of the type I interferon (IFN) signaling cascade. Patients with SGMRT develop glaucoma, an eye disease characterized by progressive vision loss due to optic nerve damage; however, the underlying molecular mechanisms remain unknown. Therefore, this project aims to determine molecular and cellular processes by which RIG-I overactivation drives SGMRT-associated glaucoma. To address this, we used a CRISPR/Cas9 knock-in (KI) mouse model carrying a Rigi gain-of-function mutation that recapitulates key features of SGMRT-associated glaucoma. Rigi KI mice with IFN receptor (IFNAR) blockade were included to examine the contribution of type I IFN signaling to ocular pathology. Further, RNA levels were explored through qPCR and single cell RNA sequencing (scRNAsq), protein levels and cell activation were explored through immunofluorescence imaging, and anatomical structures were explored through Hematoxylin and Eosin (H&E) staining. The scRNAsq analysis revealed increased IFN signaling in Rigi KI/KI mice, along with alterations in pathways related to the extracellular matrix and macrophage function. Consistent with these findings, immunostaining results showed increased macrophage presence and extracellular matrix alterations in the anterior segment of the eye, as well as higher glial activation in the retina. Finally, H&E staining results demonstrated structural differences in the cornea of Rigi KI/KI mice, which were normalized by IFNAR blockade. These findings suggest that RIG-I gain-of-function is associated with changes in molecular and cellular alterations that contribute to glaucoma development in SGMRT, and that modulation of type I IFN signaling may represent a potential therapeutic strategy.
