Figure 4.

Effects of BMCs on tubular regeneration (A–H) and renal function (I). (A) Abundant Y chromosome signals located at the periphery of the nuclei in the kidneys of male mice (red, arrows), consistent with the typical nuclear localization of the Y chromosome. The sensitivity of FISH analysis was 64% (n = 5). (B) Kidney of a female mouse without male BMC transplant shows complete absence of Y chromosome signal. (C) A tubular cell that incorporated BrdU (green) shows the presence of Y chromosome (red, arrow). (D–F) Y chromosome FISH (red) was followed by immunostaining of tubular epithelial cell markers (green). (D) The arrow indicates a Y⁺ cytokeratin⁺ tubular epithelial cell. (E) The arrow indicates a Y⁺ LTA⁺ proximal tubular cell. (F) The arrow indicates a Y⁺ AQP3⁺ collecting duct cell. Note the basolateral staining of the AQP3, which defines the intratubular localization of the Y⁺ cells. (G) Y chromosome–containing tubular cell (arrows) in the kidney of a wild-type female mouse injected with BMCs from a male cre^ksp;Z/EG donor. Arrowheads indicate interstitial cells. (H) The same cell shown in G is negative for EGFP by immunostaining (arrow). The nuclei were counterstained with DAPI (A, B, and D–H), and images were merged. Scale bars: 20 μm. (I) BUN levels in mice with sham operation that did not receive BMC injection (Control; filled triangles), mice with renal IRI that did not receive BMC injection (IRI – BMC; open circles), and mice with renal IRI that received BMC injection (IRI + BMC; filled circles). No statistically significant difference was observed in mice with or without BMC injection. n = 5–13 at each time point; total 84 mice.