Fig. 1

Celastrol preserved photoreceptor morphology in light-exposed BALB/c mice. Dark-adapted BALB/c mice were exposed to light at the intensity of 10,000 lx for 2 h after pretreatment with either vehicle control (DMSO) or celastrol at 1 mg/kg bw (celastrol 1), 2.5 mg/kg bw (celastrol 2.5), and 5 mg/kg bw (celastrol 5). a Eyes were enucleated 7 days after light exposure, and paraffin sections were made and stained with H&E for retinal histological examination using light microscopy. b ONL thickness was quantified at 500 μm off optical nerve head in both superior and inferior retina. c Dark-adapted BALB/c mice were exposed to light at the intensity of 10,000 lx for 2 h after pretreatment with either DMSO or celastrol at 5 mg/kg bw. IHC examination of rhodopsin (Rho) and opsin M (in red) expression in the central retinas (1000 μm off ONH) were performed 7 days after light exposure along with DAPI counterstaining (in blue) in the cryosections. d The thickness of ONL was measured in DAPI-stained cryosections. Asterisk indicates disorganized and reduced length of outer/inner segments and diminished ONL. ONH optic nerve head, ONL outer nuclear layer, INL inner nuclear layer. Scale bar: 50 μm. Data were expressed as mean ± S.E.M. (n = 4–6 per group). *Compared to that from no light, p < 0.05; ^#compared to that from DMSO, p < 0.05