Figure 1.
Changes in body weight, Rota-rod and open field test showed that progesterone protected cuprizone-induced mice from demyelination.
(A) Body weight in N+Veh (blue), N+P (green), CPZ+Veh (red) and CPZ+P group (brown) during the 5 weeks of treatment. There was significant difference between CPZ+Veh and N+Veh, between CPZ+Veh and CPZ+P at the fifth weeks. *CPZ+P vs. CPZ+Veh, P<0.05; **CPZ+Veh vs. N+Veh group, P<0.01. Progesterone treatment was given from 7 to 21 days (red in X axis). (B) The length of time the mice stayed on the cylinder in the Rota-rod test in N+Veh, N+P, CPZ+Veh and CPZ+P group. There was no significant difference between N+Veh and N+P group (P>0.05), between CPZ+Veh and CPZ+P group (P>0.05). The trajectories traveled by the mice in the open field test showed how the mice traveled in the N+Veh (C), N+P (D), CPZ+Veh (E) and CPZ+P groups (F). The total traveled distance (G), central area traveled distance (H), and ratio of central area distance by total traveled distance (I) in these four groups. The total traveled distance was not significantly different between N+Veh and N+P group, between the CPZ+Veh and CPZ+P groups. *CPZ+P vs. CPZ+Veh, P<0.05; **CPZ+Veh vs. N+Veh group, P<0.01.
Figure 2.
Progesterone alleviated demyelination in cuprizone-induced mouse corpus callosum and cortex by LFB, MBP staining and electron microscopy.
Luxol fast blue (LFB) staining is shown in N+Veh (A), N+P (B), CPZ+Veh (C) and CPZ+P mice (D). (E) Statistical analysis of the LFB staining results according to the relative optical density. Bar = 100 µm. MBP-stained myelin is shown in the corpus callosum of N+Veh (F), N+Veh (G), CPZ+Veh (H) and CPZ+P group (I). (J) Statistical analysis by MBP staining according to the relative optical density. MBP-stained myelin is also shown in the cortex of N+Veh (K), N+Veh (L), CPZ+Veh group (M) and CPZ+P group (N). (O) Statistical analysis by MBP staining according to the relative optical density. Bar = 50 µm. Myelin was observed in the corpus callosum of N+Veh (P), N+Veh (Q), CPZ+Veh group (R) and CPZ+P treated group (S) by electron microscopy. (T) Statistical analysis by electron microscopy. Bar = 1 µm in P, Q, R and S. *CPZ+P vs. CPZ+Veh group, P<0.05; **CPZ+Veh vs. N+Veh group, P<0.01.
Figure 3.
Progesterone rescued the loss of TUNEL-positive cells in the corpus callosum and Caspase3-positive cells in the corpus callosum of cuprizone-induced mice.
TUNEL-positive cells were observed in the corpus callosum at 3 weeks in the N+Veh (A), N+P (B), CPZ+Veh (C), and CPZ+P group (D). (E) Statistical analyses showed that TUNEL-positive cells decreased in the CPZ+P group compared with the CPZ+Veh group. Bar = 50 µm. Caspase3-positive cells were observed in N+Veh group (F), N+P group (G), CPZ+Veh group (H), and CPZ+P group (I) in the cortex of mice. (J) Statistical analyses showed that Caspase3-positive cells decreased in the CPZ+P group compared with the CPZ+Veh group. Bar = 50 µm. *CPZ+P vs. CPZ+Veh group, P<0.05; **CPZ+Veh vs. N+Veh group, P<0.01.
Figure 4.
Progesterone reduced the increase of GFAP-positive cells in the corpus callosum and increased PDGFRα-positive OPCs.
GFAP-positive cells were observed in the N+Veh group (A), N+P group (B), CPZ+Veh group (C), and CPZ+P group (D) in the corpus callosum of mice. (I) Statistical analyses showed that GFAP-positive cells decreased in the CPZ+P group compared with the CPZ+Veh group. Bar = 50 µm. *CPZ+P vs. CPZ+Veh group, P<0.05; **CPZ+Veh vs. N+Veh group, P<0.01. PDGFRα-positive OPCs were observed in the SVZ of mice in the N+Veh group (E and E’), N+P group (F), CPZ+Veh group (G), and CPZ+P group (H). (J) Statistical analyses showed that PDGFRα-positive cells increased in the CPZ+P group compared with the CPZ+Veh group. The number of PDGFRα-positive OPCs per mm2 is seen in the corpus callosum (K). Bar = 50 µm in A–H; Bar = 10 µm in E’. **CPZ+Veh vs. N+Veh group; CPZ+P vs. CPZ+Veh group, P<0.01.
Figure 5.
Progesterone rescued the loss of oligodendroglial cells in the cuprizone-induced mice.
Olig2-positive cells were observed in the corpus callosum of N+Veh (A), N+P (B), CPZ+Veh (C), and CPZ+P group (D). (E) Statistical analyses showed that Olig2-positive cells increased in the CPZ+P group compared with the CPZ+Veh group. Bar = 50 µm. *CPZ+P vs. CPZ+Veh group, P<0.05; **CPZ+Veh vs. N+Veh group, P<0.01. Sox10-positive cells were observed in the corpus callosum of mice in N+Veh (F), N+P (G), CPZ+Veh (H), and CPZ+P group (I). (J) Statistical analyses showed that the number of Sox10-positive cells increased in the CPZ+P group compared with the CPZ+Veh group. Bar = 50 µm. **CPZ+Veh vs. N+Veh, CPZ+ P vs. CPZ+Veh, P<0.01. CC-1+ mature oligodendrocytes were observed in the corpus callosum of mice in N+Veh group (K), N+P group (L), CPZ+Veh group (M), and CPZ+P group (N). (O) Statistical analysis showed that CC-1-positive cells increased in the CPZ+P group compared with the CPZ+Veh group. Bar = 50 µm. *CPZ+P vs. CPZ+Veh group, P<0.05; **CPZ+Veh vs. N+Veh group, P<0.01.