Figure 5.

Intracellular MMP12 Regulates EC Ciliogenesis

(A) Schematic of neonatal in vivo electroporation.

(B) In vivo electroporation of WT and Mmp12 mutant (Mut) mice with scrambled shRNA or Mmp12 shRNA.

(C) Left: representative images of whole-mount IHC at P7. Arrows, multiciliated H2B-CFP⁺ cells. Arrowheads, non-multiciliated H2B-CFP⁺ cells. Right: in both WT and Mut mice, Mmp12 shRNA significantly reduced the percentage of multiciliated H2B-CFP⁺ cells (WT, n = 4 mice; Mut, n = 3 mice; ^∗p < 0.05, t test).

(D) In vivo electroporation of WT mice with icMmp12 cDNA co-expressing GFP, followed by whole-mount IHC at P5.

(E) Representative IHC images at P5. Arrows, multiciliated GFP⁺ cells. Arrowheads, non-multiciliated GFP⁺ cells. The relative percentage of multiciliated GFP⁺ cells was increased by icMMP12 overexpression (Ctrl, n = 5 mice; icMmp12, n = 6 mice; ^∗p < 0.05, t test).

(F) Same experimental scheme as in (B). Upper: Representative images of FOXJ1, GFP co-IHC (arrows, FOXJ1⁺CFP⁺ cells; arrowheads, FOXJ1⁻CFP⁺ cells). Lower: The percentage of FOXJ1⁺ cells within the CFP⁺ cell population was decreased by Mmp12 shRNA (ctrl shRNA, n = 5 mice; Mmp12 shRNA, n = 4 mice; ^∗p < 0.05, t test).

Error bars denote SEM. Scale bars, 10 μm.