TY - JOUR
T1 - SAT0037 An ENPP1-Specific Inhibitor Attenuates Extracellular Ecto-Pyrophosphatase Activity in Human Osteoarthritic Cartilage
AU - Arad, U
AU - Svetitsky, S
AU - Journo, S
AU - Danino, O
AU - Fischer, B
PY - 2015
Y1 - 2015
N2 - Background. Calcium pyrophosphate deposition (CPPD) is associated with osteoarthritis (OA) and is the cause of a common inflammatory articular disease (1). Nucleotide pyrophosphatase/phosphodiesterase1 (eNPP1) is the major ecto-pyrophosphatase (NTPPPH) in chondrocytes and chondrocyte-derived matrix vesicles (MVs) (2). Thus, eNPP1 is a principle contributor to extracellular pyrophosphate levels and a potential target for interventions aimed at preventing CPPD. Recently, we synthesized and described a novel eNPP1 inhibitor (3). Objectives. To evaluate whether the eNPP1-specific inhibitor, SK4A, attenuates NTPPPH activity in human OA articular cartilage. Methods. Cartilage tissue, primary chondrocytes and cartilage-derived MVs were obtained from donors with osteoarthritis undergoing knee replacement surgery.The effect of SK4A on cell viability was assayed by the XTT method. eNPP1 expression was evaluated by Western blot. NTPPPH activity was measured by a colorimetric assay with thymidine 5'-monophosphate p-nitrophenyl ester as a substrate and by HPLC analysis of ATP levels. Results. Primary OA chondrocytes express eNPP1 in early passages, but this expression is subsequently lost upon further passaging. Similarly, significant NTPPPH activity can only be detected in early-passage human chondrocytes. The eNPP1 inhibitor, SK4A, does not affect chondrocyte viability at concentrations of up to 1mM. SK4A effectively inhibits the ex vivo NTPPPH activity in whole cartilage tissue, in isolated primary chondrocytes and in cartilage-derived MVs.
AB - Background. Calcium pyrophosphate deposition (CPPD) is associated with osteoarthritis (OA) and is the cause of a common inflammatory articular disease (1). Nucleotide pyrophosphatase/phosphodiesterase1 (eNPP1) is the major ecto-pyrophosphatase (NTPPPH) in chondrocytes and chondrocyte-derived matrix vesicles (MVs) (2). Thus, eNPP1 is a principle contributor to extracellular pyrophosphate levels and a potential target for interventions aimed at preventing CPPD. Recently, we synthesized and described a novel eNPP1 inhibitor (3). Objectives. To evaluate whether the eNPP1-specific inhibitor, SK4A, attenuates NTPPPH activity in human OA articular cartilage. Methods. Cartilage tissue, primary chondrocytes and cartilage-derived MVs were obtained from donors with osteoarthritis undergoing knee replacement surgery.The effect of SK4A on cell viability was assayed by the XTT method. eNPP1 expression was evaluated by Western blot. NTPPPH activity was measured by a colorimetric assay with thymidine 5'-monophosphate p-nitrophenyl ester as a substrate and by HPLC analysis of ATP levels. Results. Primary OA chondrocytes express eNPP1 in early passages, but this expression is subsequently lost upon further passaging. Similarly, significant NTPPPH activity can only be detected in early-passage human chondrocytes. The eNPP1 inhibitor, SK4A, does not affect chondrocyte viability at concentrations of up to 1mM. SK4A effectively inhibits the ex vivo NTPPPH activity in whole cartilage tissue, in isolated primary chondrocytes and in cartilage-derived MVs.
UR - https://www.mendeley.com/catalogue/fad4fef0-1ff0-36b6-beaa-f01ec400fa67/
U2 - 10.1136/annrheumdis-2015-eular.2707
DO - 10.1136/annrheumdis-2015-eular.2707
M3 - Article
SN - 0003-4967
VL - 74
SP - 662.1-662
JO - Annals of the Rheumatic Diseases
JF - Annals of the Rheumatic Diseases
IS - 2
ER -