Figure 3 : In vivo injection of the hMSC Secretome (i.e. CM) increases proliferation and neuronal differentiation.

Injection of the hBM-MSC CM from static and dynamic conditions into the DG of adult rat hippocampus. After 7 days post-injection, both CM (static and dynamic) were able to increase the (B,C) levels of endogenous proliferating cells (Ki-67+ cells) in the DG when compared to the (A) sham group ((J), mean ± SEM., n = 5, p < 0.05). Moreover, although both CM were able to increase the number of newborn neurons ((E,F); DCX+ cells) compared to the (D) sham group, the dynamic CM showed higher numbers of the newborn (neurons) cell densities ((K), mean ± SEM, n = 5, p < 0.05) compared to the static CM. For the induction of neuronal differentiation, both CM (from the static and dynamic conditions) were able to increase significantly the number of Ki-67+/DCX+ cells when compared to the control group ((L), mean ± SEM., n = 5, p < 0.05), with this phenomena being more evident for the group cultured with the dynamic CM. hBM-MSCs CM (from static and dynamic conditions) was also able to increase astrocytic cell densities in the DG of hippocampus. Immunohistochemical analysis of GFAP (Astrocytes; (M–O)) revealed increased numbers promoted by the injection of hBM-MSCs CM (P, statistically significant to the Sham group, mean ± SEM, n = 5, p < 0.05) 7 days post-injection. SH: Sham (animals injected with Neurobasal-A media) CMs: hBM-MSCs static conditioned media. CMd: hBM-MSCs dynamic conditioned media (Scale bar: 100 μm). Data are expressed as mean ± SEM. *p<0.05; **p<0.01.