Csf1-Csf1r expression and late circulating CSF1 elevation during P23H retinal degeneration

Retinitis pigmentosa (RP) is accompanied by retinal oxidative stress and neuroinflammation, but whether local retinal stress is associated with detectable circulating molecular changes remains unclear. Using Rho^P23H/+ mice at postnatal days 40, 90, and 240, we combined electroretinography, hematoxylin and eosin (H&E)-based outer nuclear layer (ONL) measurement, retinal qPCR, plasma redox assays, public transcriptomic reanalysis, and plasma CSF1 ELISA to characterize molecular changes during degeneration. Rho^P23H/+ mice showed progressive ERG attenuation and ONL thinning. Retinal Hmox1, Sod1, and Cat transcripts were increased, whereas plasma total oxidant status, total antioxidant status, oxidative stress index, glutathione peroxidase, total superoxide dismutase, catalase, and malondialdehyde showed no consistent genotype-dependent changes. Reanalysis of GSE152474 and GSE156533 identified immune- and glial-enriched modules containing Csf1 and Csf1r. qPCR validation showed a stage-dependent pattern of retinal Csf1 and Csf1r expression, with Csf1r increased at day 40 and both Csf1 and Csf1r increased at days 90 and 240. Plasma CSF1 concentration did not differ significantly between genotypes at day 90 but was higher in Rho^P23H/+ mice than in age-matched WT controls at day 240. These findings identify a stage-dependent pattern of retinal Csf1 and Csf1r expression and a late-stage genotype-associated difference in plasma CSF1 concentration, although the mechanistic relationship between the retinal and circulating findings remains undetermined.