Figure 4.

Locally delivered MSC increased osteoblastic lineage cell numbers in the defect, but few underwent osteogenic differentiation

(A) Fluorescent microscopy showing cells expressing the skeletal stem cell marker PRRX1 and implanted cells (fNP). Scale bars, 80 μm; c, cortical bone; d, defect area; zoomed-in images of regions enclosed by white dotted line are shown to the right, followed by 3D rendered surfaces. Scale bars, 5 μm; yellow dotted line, volume of interest (VOI); white dotted lines in the zoomed-in images, fNP+ PRRX1+ cells.

(B) Number of PRRX1+ cells; ^∗∗p < 0.01, ^∗∗∗p < 0.001, #p < 0.05, ###p < 0.001; n = 6 mice.

(C) Distances between implanted cells (fNP+) to PRRX1+ cells in defect at each time point; red dotted lines, fNP+ PRRX1+ cells (distance < 5 μm).

(D) Proportion of fNP+ PRRX1+ cells over total PRRX1+ cells in the VOI from (A); ^∗∗p < 0.01; n = 6 mice.

(E) Proportion of fNP+ PRRX1+ cells over fNP+ cells in the VOI from (A); ^∗∗∗p < 0.001; n = 6 mice.

(F) Fluorescent microscopy showing osteoblasts (OSX) and implanted cells (fNP). Scale bars, 80 μm; c, cortical bone; d, defect area; zoomed-in images of regions enclosed by white dotted line, followed by 3D rendered surfaces. Scale bars, 5 μm; the white dotted lines indicate fNP+ OSX+ cells.

(G) Number of OSX+ cells in the VOI from (F); ^∗p < 0.05; n = 6 mice.

(H) Distances between implanted cells (fNP+) to osteoblast (OSX+) in defect at each time point; red dotted lines, fNP+ OSX+ cells (distance < 5 μm).

(I and J) Proportion of fNP+ OSX+ cells over total OSX+ cells and fNP+ cells, respectively, in the VOI from (F); ^∗∗∗p < 0.001, ^∗∗∗∗p < 0.0001; n = 6 mice.