Figure 5.

Locally delivered MSCs maintained their SCA-1 expression and increased SCA-1+ cell population during bone defect repair

(A) Fluorescent microscopy showing cells with proliferative activity (KI67) and implanted cells (fNP); c, cortical bone; d, defect area. Scale bars, 80 μm; yellow dotted line, VOI.

(B) XY (top) and XZ plane (middle) of zoomed-in regions enclosed by white dotted lines in (A), followed by 3D rendered surfaces (bottom). Scale bars, 5 μm; white dotted lines, fNP+ KI67+ cells.

(C) Proportion of KI67+ cells in VOI from (A); ^∗p < 0.05; n = 6 mice.

(D) Distance distribution of fNP+ cells to KI67+ cells; region enclosed by red dotted line, fNP+ KI67+ cells (distance < 5 μm).

(E and F) Proportion of fNP+ KI67+ cells over total fNP+ cells and total KI67+ cells, respectively, at each time point. n = 6 mice.

(G) Fluorescent microscopy showing SCA-1+ cells and fNP+ implanted cells; c, cortical bone; d, defect area. Scale bars, 80 μm; yellow dotted lines, VOI; zoomed-in images of regions enclosed by white dotted line are shown to the right, followed by 3D rendered surfaces; white triangles, SCA-1+ fNP– cells; empty triangles, SCA-1+ fNP+ cells. Scale bars, 5 μm.

(H) Co-expression analysis of SCA-1 and fNP. Scale bars, 80 μm.

(I) Number of SCA-1+ cells in VOI from (G); ^∗p < 0.05, ^∗∗∗∗p < 0.0001; n = 6.

(J) Distance distribution of fNP+ cells to SCA-1+ cells; red dotted line, fNP+ SCA-1+ cells (distance < 5μm).

(K) Proportion of fNP+ SCA-1+ cells over total fNP+ cells; ^∗∗∗∗p < 0.0001; n = 6.

(L) Qualitative summary of implanted cells with stem cell marker (SCA-1) or osteogenic lineage cell marker (PRRX1, OSX) expression in defect area at each time point.