Decoding inflammaging and senescence in a novel multifactorial glaucoma model

• Applicant: Dr. Sabrina Reinehr
• Subject Area: Ophthalmology
• Term: since 2025
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 556862523

The multifactorial glaucoma disease, one of the leading causes of blindness worldwide, is defined as a loss of retinal ganglion cells (RGCs) and their axons. The exact underlying pathomechanisms are not fully understood yet. Besides elevated intraocular pressure, an altered immune system seems to be involved. Hence, in the first application, we combined two different glaucoma mouse models to create a new multifactorial one. Briefly, six-week-old wildtype (WT+ONA) and connective tissue growth factor (CTGF) mice (CTGF+ONA), a genetic ocular hypertension model, were immunized with ONA (optic nerve antigen). Wildtype (WT) and CTGF controls (CTGF) received sodium chloride. We showed a significant RGC loss in WT+ONA, CTGF, and in CTGF+ONA mice compared to the control group. The cell loss in CTGF+ONA mice was more severe than in CTGF ones. Also, optic nerves of the new CTGF+ONA animals displayed serious signs of demyelination and inflammation. Hence, we successfully established a novel multifactorial glaucoma model within the first application. Glaucoma is also an age-related disease, a factor currently not implemented in animal models. Understanding senescence and inflammaging, is fundamental to comprehend its onset, progression, and associated pathophysiological changes. Building on the results of the first project, in the follow-up application, we will (1) compare glaucomatous damage with age-associated degenerative processes. Utilizing various glaucoma models, including the novel multifactorial one, the study will assess RGC and optic nerve degeneration compared to healthy but aged mice. Employing optical coherence tomography and immunohistology, we will examine retinal thickness, morphology, RGCs, and optic nerve fibers. Additionally, the analyses encompass senescence markers and inflammatory responses via histology, Western blot, and mitochondrial functionality evaluation. (2) Secondly, we will investigate the potential acceleration of neurodegeneration and inflammation when combining glaucoma mice with a senescence model. We will compare distinct glaucoma and senescence models, examining the effects on RGCs and optic nerve degeneration, and investigating the inflammatory response using LUMINEX. Mitochondrial function assessment through extracellular flux assays remains a key component. Comparative analyses of retinal proteome changes caused by glaucoma and advanced age are performed. Proteins of interest are validated by immunohistology and Western blot. (3) Interleukin-1ß (IL-1ß) is a key inflammatory cytokine, hence, the third step is to analyze if an intravitreal injection of an IL-1ß inhibitor can prevent the progression of glaucomatous damage in the CTGF+ONA+senescence model. These projects collectively aim to unravel the complex relationship between glaucoma, aging, neurodegeneration, and inflammation. The findings hold significant promise in offering insights into potential therapeutic targets and mechanisms for combating glaucoma.

• DFG Programme: Research Grants