Figure 2. Muscle satellite cell division is impaired in the presence of septic serum.

(a) Schematic representation of the experimental approach for the in vitro test of septic conditions. (b–f) Percentage of cycling cells in different septic conditions in vitro. (b) Percentage of EdU+ myoblasts (cycling satellite cells) cultured in regular conditions (control healthy Tg:Pax7nGFP mice, control serum) or extracted from septic Tg:Pax7nGFP in normal serum (septic animal in control serum) or extracted from healthy Tg:Pax7nGFP in septic serum (control animal in septic serum) or extracted from septic Tg:Pax7nGFP in septic serum. (c–f) Representative picture of FACS cell-sorted satellite cells from Tg:Pax7nGFP mice and plated in the different conditions described above, labelled with EdU and fixed/labelled 3 days post plating. (c) Non-septic Tg:Pax7nGFP in non-septic mouse serum. (d) Healthy Tg:Pax7nGFP in septic serum. (e) Septic Tg:Pax7nGFP in non-septic serum. (f) Septic Tg:Pax7nGFP in septic serum. (g) Cells from healthy (non-septic) and septic Tg:Pax7nGFP mice were FACS cell sorted and plated at 100 cells per well density. Clonal analysis of the proliferation through time (from T0 to 7 days post plating) was performed using Opera system (automatic clonal cell count). (h–l) Live video microscopy of all conditions previously mentioned (see a). (h) Control (that is, healthy cells in non-septic mouse serum), (i) healthy cells in septic serum, (j) septic cells in non-septic serum and (k) septic cells in septic serum. (l) Velocity of cells measured in μm h⁻¹ in all four conditions. Tg:Pax7nGFP mice were between 8 and 12 weeks old, n=4. Data are represented as mean±s.d. *P<0.05; **P<0.01; ***P<0.001; ****P<0.0001 (Mann–Whitney test). GFP, green fluorescent protein; NS, not significant.