Alkaline phosphatase activity kit

Fetal bovine serum was purchased from Atlanta Biologicals (Atlanta,
Georgia). Culture media, trypsin-EDTA reagent, antibiotics, Lipofectamine
RNAimax, and siRNA were obtained from Invitrogen (Carlsbad, CA). RNeasy mini kit
(Qiagen, Frederick, MD) and cDNA Synthesis Kit (Bio-Rad, Hercules, California)
were used for RT-PCR. Antibodies for immunoblot and immunofluorescence were
obtained from Abcam (Cambridge, MA), Cell signaling (Danvers, Massachusetts),
Invitrogen, BD (Franklin Lakes, New Jersey), Santa Cruz (Dallas Texas), or
Jackson Immunoresearch Laboratories (West Grove, Pennsylvania) as detailed
below. Alkaline phosphatase activity kit was purchased from Abcam. Antibodies
used are shown in a table in the supplementary data set (Table S1).

The cell culture supernatant was collected at 1, 4, 7, 10, and 14 days (Figure 1B). An ALP activity assay was performed using the colorimetric Alkaline Phosphatase Activity Kit from Abcam (Cambridge, MA, USA) according to the manufacturer’s protocol and the absorbance was measured at OD 405 nm.