Rac1 impairs retinal axon degeneration via Kif2a in a mouse model of chronic ocular hypertension
Rac1, a member of the small G protein Rho family, has been implicated in neurodegenerative diseases. However, its role in axon degeneration is not fully understood. Here we found that activation of Rac1 exacerbated axonal transport damage in an experimental glaucoma model. Inhibiting Rac1 activity by genetic or pharmacological methods alleviated the dysfunction of axonal transport and improved the integrity of microtubule by upregulating the expression of ß-III tubulin and myelin basic protein. Rac1 interacted with Sirt1, a key molecule of Wallerian degeneration, which regulated the activity of PAK1, a downstream molecule of Rac1. Furthermore, Rac1 modulated Kif motors at the transcriptional level, among which Kif2a, a lysosome-location regulator, was negatively regulated by Rac1. Intravitreal injection of Kif2a siRNA reversed the improvement of Rac1 inhibition-mediated axonal transport through reducing autophagolysosomes. Our results suggest that Rac1/Kif2a accelerates the process of RGC axon degeneration by impairing the autophagic flux in glaucoma, which may be an intriguing therapy target for glaucoma. Overall design: CUT&Tag sequencing from retinal cells of control and COH 1w retinas to search for Rac1-related genes and transcription factors.