Reduced
Hh signaling activity partially rescued joint calcification of Enpp1−/− mice. (A-D) Representative images of Alcian Blue and Alizarin Red stained forelimbs from 3-month-old Enpp1−/− (A), Enpp1+/−; Gli2+/− (B), Enpp1−/− (C) and Enpp1−/−; Gli2+/− (D) mice. (A′,B′,C′,D′) Phalangeal joints shown at higher magnification. (E-G) Representative ALP staining of SMPs from WT (E), Enpp1+/−; Gli2+/− (F), Enpp1−/− (G) and Enpp1−/−; Gli2+/− mice (H) cultured in osteogenic medium for 7 days. (I) Quantification of the relative metacarpophalangeal joint sizes. Littermates were used in this experiment, n=4. (J) qRT-PCR analysis of Hh target and osteoblast genes expressed in SMPs of indicated genotypes. SMPs were cultured in osteogenic medium for 7 days (n=3). NS, not significant, *P<0.05, **P<0.01, ***P<0.001 (Student's t-test).