Western Blot Analysis of Dental Proteins

Total cell proteins were lysed using radioimmunoprecipitation assay (Beyotime) according to the manufacturer’s protocol. Proteins in the conditioned medium were extracted using a liquid sample total protein extraction kit (Solarbio, Beijing, China). Western blotting was performed as previously described [10 (link)]. The primary antibodies used were anti-SCUBE3 (ab189955; Abcam), anti-AMBN (orb155652; Biorbyt, Cambridge, UK), TGFβR1 (ab31013; Abcam), anti-DSPP (sc-73632; Santa Cruz), anti-DMP1 (ab103203; Abcam), anti-OPN (ab8448; Abcam), anti-OSX (ab13418; Abcam), anti-BMP2 (ab14933; Abcam), anti-BMPR1A (ab264043; Abcam), anti-p-SMAD1/5 (9516; Cell Signalling Technology, Boston, MA, USA), and anti-SMAD1 (D59D7; Cell Signalling Technology). Anti-GAPDH (Rayantibody, Beijing, China) was used as an internal control. Antibody binding was detected using an enhanced chemiluminescence kit (Millipore, Billerica, MA, USA). The intensity of the bands was quantified using the ImageJ software (NIH, USA).