Fig. 5.

Wingless-type MMTV integration site family member 3A (wnt-3a) increases CCN1 in myoblasts; Wnt-3a is increased in old human and mouse serum. A: C2C12 myoblasts at 80% confluence were transduced with adenoviral wnt-3a (Ad-Wnt-3a; transduction unit 10⁹) for the indicated times. Western blots were used to detect the abundance of CCN1 or GAPDH. The bar graph shows the density of CCN1 bands expressed as a fold change from 0 (with Ad-ctrl treatment, set to 1-fold) after normalization to the density of GAPDH (bars: means ± SE; n = 3; *P < 0.05 vs. Ad-ctrl treatment). B: dose response of CCN1 and CCN2 to wnt-3a. C2C12 cells at 80% confluence were transduced with recombinant adenovirus Ad-wnt-3a at the indicated titer. Western blots were used to detect the abundance of CCN1 or GAPDH. Bar graph shows the density of CCN1 bands expressed as a fold change from 0 (Ad-ctrl treatment, set to 1-fold) levels after normalization to the density of GAPDH (n = 3; *P < 0.05 vs. Ad-ctrl). C: wnt-3a protein amount was measured in young (Y) and old (O) human and mouse serum samples using immunoprecipitation followed by Western blot. Immunoprecipitated band densities were divided by the concentrations of protein in the original serum samples to correct for original protein content of the immunoprecipitation reactions. Bar graph shows the mean corrected density of wnt-3a bands expressed as a fold change from young levels (bar: means ± SE, n = 6; *P < 0.05 vs. young set to 1-fold).