Neutral endopeptidase (EC 3.4.24.11) is highly expressed on osteoblastic cells and other marrow stromal cell types.
A series of cultured mouse marrow stromal cell lines of different phenotype characteristics were examined for their neutral endopeptidase (NEP) activity using the highly selective chromophoric substrate of enzyme, 3-carboxypropanoyl-alanyl-alanyl-leucine 4-nitroanilide. All the cell lines tested contained appreciable amounts of NEP activity, but the cells expressing an osteoblastic phenotype, MBA-15, showed the high levels. Other non-stromal osteoblastic cell lines, MC-3T3-E1, ROS 17/2.8 cells derived from mouse long bone explants, were also rich in NEP. A four-fold stimulation of NEP activity was observed when certain MBA-15 clones were cultured in the presence of 1 alpha,25-dihydroxyvitamin D3. Since NEP is an effective cell-surface endopeptidase, it may play a role in the dynamics of bone formation, via interaction with biologically active polypeptides.
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Sackler Institute of Molecular Medicine, Sackler Faculty of Medicine, Tel Aviv University, Israel.
Benayahu
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D
Fried
A
A
Wientroub
S
S
Blumberg
S
S
D000595:Amino Acid Sequence; D000818:Animals; D001853:Bone Marrow / Q000201:enzymology*; D001854:Bone Marrow Cells; D002117:Calcitriol / Q000494:pharmacology; D002460:Cell Line; D002462:Cell Membrane / Q000201:enzymology; D007700:Kinetics; D051379:Mice; D008969:Molecular Sequence Data; D015260:Neprilysin / Q000378:metabolism*; D010006:Osteoblasts / Q000201:enzymology*; D051381:Rats; D013379:Substrate Specificity
D015260:Neprilysin; D002117:Calcitriol