Fig. 3: Deletion of Prdx1 induces lipid accumulation and testosterone insufficiency in LCs.

a ELISA assay of serum luteinizing hormone (LH) levels in 2- and 6-month-old Ctrl and cKO mice. b mRNA levels of the genes participating in testosterone biosynthesis in Ctrl and cKO mice. Total triglyceride (TG, c) and total cholesterol (TC, d) levels in testes. Total testis homogenates were used and values are presented as mg/g protein. Total triglyceride (e), total cholesterol (f), and free cholesterol (FC, g) levels in freshly isolated LCs. Total LC homogenates were used and values are presented as mg/g protein. h Ratio of free to total cholesterol in freshly isolated LCs. i Testosterone levels in freshly isolated LCs. Values are presented as μg/g protein. n = 5 biological replicates. j mRNA levels of Ldlr and Scarb1 in testes. k mRNA levels of adult and fetal LC markers in testes. l, m Oil red O staining showing lipid deposition in testicular interstitial area. Lipid droplets (LDs) with a diameter <0.5 μm (small, S), 0.5–1.0 μm (median, M), >1 μm (large, L) were counted and quantification was showed in (m). n, o BODIPY 493/503 staining showing lipid deposition (green) in testicular interstitial area. Quantification was showed in (o). p–r Co-fluorescence of BODIPY 493/503 (green) and LC3 (red) in interstitial area. Relative intensity within the indicated area outlined in (p) was measured and the values indicate percentages of colocalizing signals (q). A.U., arbitrary units. Pearson’s colocalization coefficients were determined (r). s, t TEM images displaying LDs and LD-autophagic vacuole (AV) contacts in interstitial area. Yellow asterisks indicate LDs, blue triangles indicate AV-associated LDs. Magnification and quantification were showed in (t). Values indicate the percentage of AV-associated LDs. u WB analyses of LC3 and p62 levels in testes. The relative levels of LC3-II/LC3-I and p62/tubulin were presented. Total testis extracts were used. All mice tested were 3 months old unless otherwise specified. Five mice from each group were analyzed (n = 5). *P < 0.05, **P < 0.01, ***P < 0.001. n.s. not significant. All values represent Mean ± SEM. Data in (c–i), (o) (r) and (t) were analyzed by t-test, others by one-way ANOVA followed by the Dunnett test for between-group differences. Nuclei were stained with DAPI (blue). Scale bars = 10 μm in (l), 20 μm in (n), 100 μm in (p), and 1 μm in (s).