Retinal neuroinflammation and neurodegeneration in a mouse model of glaucoma: cilastatin as a protective agent in male and female mice

Background Glaucoma is a leading cause of irreversible blindness characterized by retinal ganglion cell degeneration and neuroinflammation. Although sex-related differences have been reported in glaucoma, most experimental studies have predominantly used male animals. This study evaluated retinal responses to experimental glaucoma and the neuroprotective effects of cilastatin in male and female pigmented C57BL/6J mice. Methods Ocular hypertension (OHT) was induced by unilateral laser photocoagulation of the left eye in male and female C57BL/6J mice. Animals received daily cilastatin (300 mg/kg, i.p.) or vehicle from 2 days before surgery until sacrifice at 28 days. Intraocular pressure was monitored throughout the study. Brn3a+ retinal ganglion cells, GFAP+ macroglial cells, and Iba-1+ microglial cells were assessed by immunohistochemistry and quantitative image analysis. OHT, normotensive contralateral (CONTRA) and NAÏVE eyes were compared in both sexes and treatment groups. Results OHT increased intraocular pressure in both sexes and was associated with a reduction in Brn3a+ RGCs, in both male and female mice. In sex-stratified analyses, regional and layer-specific assessments revealed distinct descriptive spatial patterns of retinal inflammation, with differing microglial and macroglial reactivity profiles observed in the male and female cohorts. Cilastatin did not produce a sustained IOP-lowering effect but significantly attenuated the OHT-associated reduction in Brn3a+ RGCs and reduced glial activation in both sexes. Conclusion Experimental glaucoma induces neurodegenerative and neuroinflammatory retinal responses in pigmented C57BL/6J mice, with distinct descriptive spatial patterns observed between sexes. Cilastatin attenuated the OHT-associated reduction in Brn3a+ RGC counts and glial activation without producing a sustained IOP-lowering effect, supporting further investigation of its potential relevance in glaucoma.