TY - JOUR
T1 - An optimized method for the chemiluminescent detection of alkaline phosphatase levels during osteodifferentiation by bone morphogenetic protein 2
AU - Blum, Jeremy S.
AU - Li, Rebecca H.
AU - Mikos, Antonios G.
AU - Barry, Michael A.
PY - 2001/3/15
Y1 - 2001/3/15
N2 - Differentiation of osteoprogenitor cells into osteoblasts is a pivotal step during the normal development and repair of bone. Upregulation of endogenous cellular alkaline phosphatase activity (AP) is a commonly used intracellular marker for the assessment of osteoprogenitor cell differentiation into the osteoblastic phenotype. Current methods for assaying AP involve colorimetric detection of the enzyme's activity using the synthetic substrate ρ-nitrophenol phosphate. In this paper, we explored an alternative method of detecting AP using the chemiluminescent substrate disodium 3-(4-methoxyspiro{1,2-dioxetane-3,2′-(5′-chloro)tricy clo[3.3.1.13,7]decan}-4-yl) phenyl phosphate (CSPD) for enhanced AP sensitivity and a more simplified assay. Using calf intestinal alkaline phosphatase as a standardizing enzyme, we determined that the chemiluminescent detection system was four orders of magnitude more sensitive than the standard colorimetric method of detection. Moreover, the chemiluminescent assay was faster and markedly simpler to perform. To maximize the utility of this assay system, two osteoprogenitor cell lines were compared for their ability to generate alkaline phosphatases in vitro when exposed to recombinant human bone morphogenetic protein (rhBMP-2). The W20-17 cell line was substantially more sensitive to rhBMP-2 than the C3H10T1/2 cell line, where each cell line produced detectable increases in AP after exposure to rhBMP-2 levels of 5 and 25 ng/ml, respectively. The experimental design for AP responsiveness to rhBMP-2 was further optimized for chemiluminescent detection with the W20-17 cell line by comparing the effects of reporter cell seeding density and the day of assay. In summary, the data presented in this paper demonstrate a faster, simpler, and more sensitive chemiluminescent method to monitor changes in AP levels during osteodifferentiation.
AB - Differentiation of osteoprogenitor cells into osteoblasts is a pivotal step during the normal development and repair of bone. Upregulation of endogenous cellular alkaline phosphatase activity (AP) is a commonly used intracellular marker for the assessment of osteoprogenitor cell differentiation into the osteoblastic phenotype. Current methods for assaying AP involve colorimetric detection of the enzyme's activity using the synthetic substrate ρ-nitrophenol phosphate. In this paper, we explored an alternative method of detecting AP using the chemiluminescent substrate disodium 3-(4-methoxyspiro{1,2-dioxetane-3,2′-(5′-chloro)tricy clo[3.3.1.13,7]decan}-4-yl) phenyl phosphate (CSPD) for enhanced AP sensitivity and a more simplified assay. Using calf intestinal alkaline phosphatase as a standardizing enzyme, we determined that the chemiluminescent detection system was four orders of magnitude more sensitive than the standard colorimetric method of detection. Moreover, the chemiluminescent assay was faster and markedly simpler to perform. To maximize the utility of this assay system, two osteoprogenitor cell lines were compared for their ability to generate alkaline phosphatases in vitro when exposed to recombinant human bone morphogenetic protein (rhBMP-2). The W20-17 cell line was substantially more sensitive to rhBMP-2 than the C3H10T1/2 cell line, where each cell line produced detectable increases in AP after exposure to rhBMP-2 levels of 5 and 25 ng/ml, respectively. The experimental design for AP responsiveness to rhBMP-2 was further optimized for chemiluminescent detection with the W20-17 cell line by comparing the effects of reporter cell seeding density and the day of assay. In summary, the data presented in this paper demonstrate a faster, simpler, and more sensitive chemiluminescent method to monitor changes in AP levels during osteodifferentiation.
KW - Alkaline phosphatase activity
KW - BMP-2
KW - Bone formation
KW - C3H10T1/2
KW - Osteoblast
KW - Osteoblastic differentiation
KW - Osteoprogenitor cells
KW - W20-17
UR - http://www.scopus.com/inward/record.url?scp=0035144835&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0035144835&partnerID=8YFLogxK
U2 - 10.1002/1097-4644(20010315)80:4<532::AID-JCB1007>3.0.CO;2-B
DO - 10.1002/1097-4644(20010315)80:4<532::AID-JCB1007>3.0.CO;2-B
M3 - Article
C2 - 11169737
AN - SCOPUS:0035144835
SN - 0730-2312
VL - 80
SP - 532
EP - 537
JO - Journal of cellular biochemistry
JF - Journal of cellular biochemistry
IS - 4
ER -