The effect of molecules in mother-of-pearl on the decrease in bone resorption through the inhibition of osteoclast cathepsin K.
This study evaluates the effect of the mother-of-pearl (nacre) organic matrix on mammalian osteoclast activity and on cathepsin K protease. Rabbit osteoclasts were cultured on bovine cortical bone slices in the presence of water-soluble molecules extracted from nacre of the pearl oyster Pinctada margaritifera. Osteoclast resorption activity was determined by quantification of the resorption surface area on bovine bone slices. Papain and cathepsin K, B and L inhibition tests were performed in the presence of the nacre water-soluble extracts. The active crude extract was fractionated by dialysis and reversed-phase high-performance liquid chromatography before electrospray mass spectrometry analysis of inhibitory fractions. The water-soluble molecules extracted from nacre decreased bone resorption without jeopardizing osteoclast survival. The hydrolytic activity of cysteine proteinases was reduced when the enzymes were incubated with the nacre water-soluble molecules. Trending towards characterization of the molecules involved, it appears that cathepsin K inhibitors remain in different nacre water-soluble organic matrix subfractions, composed of low molecular weight molecules. Mollusk shell nacre contains molecules capable of reducing osteoclast bone resorption activity by inhibiting cathepsin K, giving a new facet of the bioactivity of nacre as bone biomaterial.
Muséum National d'Histoire Naturelle, UMR/CNRS 5178 "Biologie des Organismes Marins et Ecosystèmes", ERT "Valorisation de Molécules Bioactives d'Origine Marine", CP 26, 43 rue Cuvier, 75231 Paris Cedex 05, France. duplat@mnhn.fr
Denis
D
Duplat
Marlène
M
Gallet
Sophie
S
Berland
Arul
A
Marie
Lionel
L
Dubost
Marthe
M
Rousseau
Saïd
S
Kamel
Christian
C
Milet
Michel
M
Brazier
Evelyne
E
Lopez
Laurent
L
Bédouet
D000818:Animals; D001862:Bone Resorption / Q000473:pathology / Q000503:physiopathology* / Q000517:prevention & control*; D056657:Cathepsin K; D002403:Cathepsins / Q000037:antagonists & inhibitors*; D002478:Cells, Cultured; D016326:Extracellular Matrix Proteins / Q000008:administration & dosage*; D008422:Materials Testing; D010010:Osteoclasts / Q000187:drug effects* / Q000473:pathology; D010125:Ostreidae / Q000737:chemistry*; D011817:Rabbits
D016326:Extracellular Matrix Proteins; D002403:Cathepsins; D056657:Cathepsin K