(A) NO level was measured by DAF-FM fluorescence intensity in ST2 cells after siRNA-mediated Asl knockdown. n = 8. (B) mRNA levels of Asl, Runx2, Osx, Alp, and Col1a1 by qPCR in ST2 cells. Asl-knockdown ST2 cells were differentiated in osteogenic medium for 3 days. n = 4. (C) mRNA levels of Asl, Runx2, Osx, Alp, Col1a1, and osteocalcin (Ocn) by qPCR in BMSC-derived osteoblasts from WT and AslNeo/Neo mice. BMSCs were cultured in osteogenic medium for 14 days. n = 3. (D) Alizarin red staining of BMSC-derived osteoblasts from WT and AslNeo/Neo mice. BMSCs were cultured in osteogenic medium for 14 days. n = 3. Data are presented as mean ± SD. *P < 0.05; **P < 0.01; ***P < 0.005 by Student’s t test.