Depletion of the Third Complement Component Ameliorates Age-Dependent Oxidative Stress and Positively Modulates Autophagic Activity in Aged Retinas in a Mouse Model

Figure 1

Functional and morphological evaluation of aged retinas from C3−/− and WT mice. (a) The representative rod, mixed rod-cone, and cone responses, as well as oscillatory potentials (OPs), recorded from 12-month-old C3-deficient (C3-def) and WT mice are shown. Changes in the retinal bioelectrical response during aging are presented as a percentage value calculated for each individual 1-year-old mice in reference to the b-wave amplitude measurements obtained from 3-month-old mice (considered 100%). The results are shown as mean ± SD ( mice per group). The ERG recordings at 12 months of age were reduced in both C3−/− and WT mice ( for scotopic and photopic conditions); however, when analyzing mixed rod-cone responses and OPs, the b-wave amplitudes in C3-deficient mice were significantly higher () compared to age-matched WT animals. (b) The representative in vivo SD-OCT retinal scans and H&E-stained images of 3- and 12-month-old C3-def and WT mice are shown. The scale bar is 20 μm. (c) Spectral domain optical coherence tomography was used to assess the changes in retinal morphology and thickness over time. Changes in retinal thickness are presented as a percentage value calculated for each individual 1-year-old mice in reference to measurements obtained from 3-month-old mice (considered 100%). The results are shown as mean ± SD ( mice per group). Aged retinas of both C3-def and WT mice showed the signs of declined thickness (); however, this process was more profound in WT mice (). (d) Immunofluorescence analysis of complement component C3 in aged WT retinas revealed deposition of the protein in the sub-RPE region. The sections from 12-month-old C3-deficient animals served as a staining control. The scale bar is 20 μm.

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