Fig. 4

Ketogenic diet induces anti-inflammatory IL-4 and Arginase-1 expression in D2 retina and ON. a Bar graph showing Il-4 mRNA normalized to Hprt mRNA by qRT-PCR in untreated (Unt) and keto D2 retina, *p = 0.0264; n = 8 samples per group. b, c IL-4 protein levels in the retina (b), **p = 0.0014, and ON (c), *p = 0.0121, analyzed by ELISA; n = 8 samples per group. d Arg1 mRNA levels in retina normalized by Hprt mRNA levels, *p = 0.0368; n = 8 samples per group. e Immunohistochemical analysis of Arginase-1 (green) in the untreated and keto D2 retina and ON. Iba1 (red) labels microglia and DAPI stains nuclei. f, g Percentage of mean fluorescence of Arginase-1 in inner retina (f), ***p = 0.0001, and in the ROI of the proximal ON (g), ***p = 0.0001; five retinas and ON from each group were analyzed, with five sections from each individual retina and ON. h Western blot analysis of Arginase-1 protein in the retina. i Quantification by densitometry of Arginase-1 levels normalized to β-actin levels, ***p = 0.0001; n = 3 blots per group, each with independent samples. j Arginase-1 protein in the ON normalized to β-actin levels, as determined by capillary electrophoresis, **p = 0.0006; n = 3 ON per group. All bar graphs are presented as the mean ± SEM, analyzed by two-tailed unpaired t test. Scale bar, 20 μm