Figure 6.

Pre-treatment with DMDFs Promotes Proliferation of Satellite Cells

(A) A schematic illustrating the experimental procedure. To evaluate the effect of pre-treated metabolic enzymes on population expansion of satellite cells, individual myofibers were freshly isolated from EDL muscles and treated with recombinant metabolic enzyme proteins in DMEM for 48 h, and then the culture media were replaced with growth-factor-rich medium (GM) to stimulate activation for a further 24 h. PBS and urease were used as a negative control and a non-muscle enzymatic control, respectively.

(B and C) (B) Immunostaining of satellite cells associated with individual myofibers for PAX7 and MYOD (quantified in C). (Left, absolute numbers of positive cells; right, relative ratio of positive cells.) Scale bars, 50 μm. Values are means ± SE (n = 4 in each condition). Asterisk (^∗), dagger (†), and pound sign (#) indicate differences in the total, differentiated (PAX7⁻MYOD⁺), and activated (PAX7⁺MYOD⁺) cell populations, respectively, compared with urease control (p < 0.05).

(D–F) (D) A schematic illustrating the experimental procedure for EdU incorporation. (E) Immunostaining of satellite cells associated with individual myofibers for PAX7 and EdU. (F) Absolute numbers of positive cells are shown. PBS and urease were used as a negative control and a non-muscle enzymatic control, respectively. Scale bars, 50 μm. Values are means ± SE (n = 4 mice). Asterisk (^∗) and pound sign (#) indicate differences in the total and activated/proliferative (PAX7⁺EdU⁺) cell populations, respectively, compared with urease control (p < 0.05).