Figure 3.

Cell aggregates identified from C57VCI mice that received MSC injections. (A) Based on the H&E stains, an accumulation of pyknotic cells was identified from the hippocampal fimbria of C57VCI mice from the MSC group (n = 6). L indicates left and R indicates the right hemisphere of the mouse brain. Scale bar = 2 mm (whole brain, top), 200 µm (bottom). (B) Immunohistochemical (IHC) staining using the STEM121 marker indicated that no human MSCs are present in the hippocampal fimbria (region demarcated with broken white lines) of the MEM group while a very small percentage of human MSCs is present in the cell aggregate of the MSC group. Scale bar = 100 µm. (C) CD45 and Iba-1 markers were used to detect the presence of leukocytes and microglia/macrophage, respectively. In the damaged area of the cortex (the gap in between the broken white lines displays the site of Hamilton syringe injection), MEM (n = 5) and MSC-injected C57VCI mice (n = 6) did not display significant differences in both CD45 and Iba-1 expression levels. Scale bar = 100 µm. (D) Compared to the MEM group, statistically significant differences in both CD45 and Iba-1 expression levels of the MSC group were observed in the hippocampal fimbria (region demarcated by broken white lines). * p < 0.05 vs. MEM; mean ± S.E.M. Scale bar = 100 µm.