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

Figure 2

Evaluation of oxidative stress markers and apoptotic activity in the retinas of aged C3-deficient and WT mice. (a) Western blot and densitometry analysis of 4HNE, catalase, glutathione reductase (GSR), and β-actin, which served as an internal control. Immunoblot images are representative of three independent experiments yielding similar results. The protein expression level of the 4HNE, catalase, and GSR was quantified in comparison to that of β-actin and shown as mean ± SD ( eyes per group). 4HNE-modified proteins, an oxidative stress marker, were detected in both 12-month-old C3-def and WT mice, although the 4HNE/β-actin ratio was significantly lower in the retinas collected from C3-def mice (). Moreover, catalase and GSR levels, which represent antioxidant enzymes, were considerably higher in C3-deficient mice (). (b) Luminex multiplex fluorescent bead-based immunoassay was used to evaluate protein expression level of survivin, Mcl-1/Bak dimer, and active caspase-3 in retinal lysates. To standardize the final concentration values, the obtained data was normalized to the total protein concentration. The results are shown as mean ± SD ( eyes per group). C3-def mice demonstrated higher rates of survivin and Mcl-1/Bak dimer (), which represent antiapoptotic proteins (). The rates of active caspase-3 were considerably lower in C3-def mice () as compared to age-matched control mice.

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