Abstract | OBJECTIVE: METHODS: To achieve "gain of function" of NTPPPH isozymes, we expressed the isozymes in cultured chondrocytic cells. RESULTS: Plasmid cDNA transfection of PC-1, but not ATX or B10/PDNP3, markedly increased apoptosis of cultured chondrocytic knee meniscal cells and increased calcium precipitation by MV fractions. The capacity of PC-1 to increase chondrocyte and meniscal cell apoptosis, and calcium precipitation by MV, further analyzed using adenoviral gene transfer in cultured meniscal cells and articular chondrocytes, was shown to be dependent on integrity of the PC-I NTPPPH catalytic site. The MV-containing fraction released from meniscal cells and chondrocytes that overexpressed wild-type PC-1 had increased annexin V. Use of antibodies to annexin V and PC-1 revealed that both annexin V and PC-1 directly mediated the elevated calcium-precipitating capacity of MV. The increased ability of MV to precipitate calcium from PC-1-overexpressing cells did not require exogenous ATP. CONCLUSION: Upregulated expression of enzymatically active PC-1 directly promotes apoptosis, increased MV annexin V, and an increased capacity of meniscal cell and articular chondrocyte MV to precipitate calcium. These results suggest a direct link between increased PC-1 expression and the pathogenesis of chondrocalcinosis.
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Authors | K Johnson, K Pritzker, J Goding, R Terkeltaub |
Journal | The Journal of rheumatology
(J Rheumatol)
Vol. 28
Issue 12
Pg. 2681-91
(Dec 2001)
ISSN: 0315-162X [Print] Canada |
PMID | 11764218
(Publication Type: Journal Article, Research Support, Non-U.S. Gov't, Research Support, U.S. Gov't, Non-P.H.S., Research Support, U.S. Gov't, P.H.S.)
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Chemical References |
- Glycoproteins
- Isoenzymes
- Membrane Glycoproteins
- Multienzyme Complexes
- Recombinant Proteins
- Phosphoric Diester Hydrolases
- Phosphodiesterase I
- ectonucleotide pyrophosphatase phosphodiesterase 1
- alkylglycerophosphoethanolamine phosphodiesterase
- Caspase 1
- Pyrophosphatases
- nucleoside triphosphate pyrophosphatase
- Glucose-6-Phosphate Isomerase
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Topics |
- Apoptosis
- Cartilage, Articular
(cytology, enzymology, pathology)
- Caspase 1
(metabolism)
- Cells, Cultured
- Chondrocalcinosis
(enzymology, pathology)
- Chondrocytes
(enzymology, pathology)
- Extracellular Matrix
(enzymology)
- Glucose-6-Phosphate Isomerase
(genetics, metabolism)
- Glycoproteins
(genetics, metabolism)
- Humans
- In Situ Nick-End Labeling
- Isoenzymes
- Knee Joint
- Membrane Glycoproteins
(genetics, metabolism)
- Multienzyme Complexes
- Phosphodiesterase I
- Phosphoric Diester Hydrolases
- Pyrophosphatases
(genetics, metabolism)
- Recombinant Proteins
- Transfection
- Up-Regulation
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