Fig. 6

Cathepsins are elevated in the microglia depleted cell fraction of aged Grn^−/− mice. a-d Cathepsin expression and maturation in the CD11b-positive, microglia enriched, fraction and the CD11b-negative, microglia depleted cellular fraction isolated form cortices of brains from 12-month-old Grn^+/+ (wt) and Grn^−/− (ko) mice. Representative immunoblots for the expression of CatD (a, b), CatB (c, d). The molecular weight standards in kilo Daltons (kDa) are indicated on the left side of all immunoblots. A dotted line in the blot indicates that samples of heterozygous mice were cut out, but all samples were loaded on one gel. Quantification of immunoblots for total cathepsin or pro-form (p), single chain (sc) and heavy chain (hc) normalized to wt are shown as mean ± SD. For statistical analysis the unpaired, two-tailed student’s t-test was used to compare ko to wt mice (n = 3–5) (*, p < 0.05; **, p < 0.01; ***, p < 0.001; ns, not significant) (a-d)