Biomaterial Database

Contortrostatin, a homodimeric snake venom disintegrin, is a potent inhibitor of osteoclast attachment. 1998

B Mercer, and F Markland, and C Minkin

Department of Basic Sciences, School of Dentistry, University of Southern California, Los Angeles 90089-0641, USA.

Disintegrins are small disulfide-rich proteins containing an Arg-Gly-Asp (RGD) sequence near their carboxyl terminus. These polypeptides inhibit binding of adhesion molecules to their receptors (integrins) on the surface of cells. Osteoclasts express integrins, heterodimeric cell surface adhesion receptors, that have been shown to be involved in interactions with the extracellular matrix (ECM), including attachment to bone and bone resorption. It has recently been shown that disintegrins effectively inhibit attachment of osteoclasts to components of the ECM and also disrupt osteoclast-mediated bone resorption. Here we characterize the effects of contortrostatin (CTS), a novel homodimeric snake venom disintegrin, on osteoclast attachment. Plastic dishes coated with CTS were able to support osteoclast attachment with a high affinity (EC50,CTS = 86 +/- 6.7 nM) similar to that of vitronectin (VTN; EC50,VTN = 80 +/- 20 nM). Further, CTS was observed to inhibit completely osteoclast attachment to fetal bovine serum (FBS; IC50,FBS = 0.36 +/- 0.04 nM) and VTN (IC50,VTN = 0.85 +/- 0.13 nM). We used monoclonal antibodies directed against the beta1 (monoclonal antibody [MAb] CD29) and beta3 (MAb F11) integrin subunits to explore the mechanism of osteoclast attachment to immobilized CTS. Only MAb F11 inhibited attachment to immobilized CTS (IC50 = 0.41 +/- 0.12 microg/ml), suggesting that binding to CTS is mediated in part by a beta3 integrin, presumably the alpha(v)beta3 VTN receptor. In further support of an integrin-mediated mechanism, binding of osteoclasts to CTS is inhibited by the RGD peptide, GRGDSP. CTS was also more potent (IC50,FBS = 0.36 +/- 0.04 nM) at inhibiting osteoclast attachment to FBS-coated wells than the monomeric snake venom disintegrin echistatin (IC50,FBS = 8.9 +/- 1.5 nM) or VTN (IC50FBS = 97.5 +/- 25.5 nM). Taken together, these data suggest that the snake venom disintegrin CTS is a potent inhibitor of beta3 integrin-mediated osteoclast attachment, presumably involving the VTN receptor (an alpha[v]beta3 integrin). Further studies of the mechanism of CTS-osteoclast interactions may aid in the design of peptide mimetics to act as antiresorptive agents for the treatment of osteoporosis and other skeletal pathology.

UI	MeSH Term	Description	Entries
D009842	Oligopeptides	Peptides composed of between two and twelve amino acids.	Oligopeptide
D010010	Osteoclasts	A large multinuclear cell associated with the BONE RESORPTION. An odontoclast, also called cementoclast, is cytomorphologically the same as an osteoclast and is involved in CEMENTUM resorption.	Odontoclasts,Cementoclast,Cementoclasts,Odontoclast,Osteoclast
D010975	Platelet Aggregation Inhibitors	Drugs or agents which antagonize or impair any mechanism leading to blood platelet aggregation, whether during the phases of activation and shape change or following the dense-granule release reaction and stimulation of the prostaglandin-thromboxane system.	Antiaggregants, Platelet,Antiplatelet Agent,Antiplatelet Agents,Antiplatelet Drug,Blood Platelet Aggregation Inhibitor,Blood Platelet Antagonist,Blood Platelet Antiaggregant,PAR-1 Antagonists,Platelet Aggregation Inhibitor,Platelet Antagonist,Platelet Antagonists,Platelet Antiaggregant,Platelet Antiaggregants,Platelet Inhibitor,Protease-Activated Receptor-1 Antagonists,Antiplatelet Drugs,Blood Platelet Aggregation Inhibitors,Blood Platelet Antagonists,Blood Platelet Antiaggregants,Platelet Inhibitors,Agent, Antiplatelet,Aggregation Inhibitor, Platelet,Antagonist, Blood Platelet,Antagonist, Platelet,Antiaggregant, Blood Platelet,Antiaggregant, Platelet,Drug, Antiplatelet,Inhibitor, Platelet,Inhibitor, Platelet Aggregation,PAR 1 Antagonists,Platelet Antagonist, Blood,Platelet Antiaggregant, Blood,Protease Activated Receptor 1 Antagonists
D010980	Platelet Membrane Glycoproteins	Surface glycoproteins on platelets which have a key role in hemostasis and thrombosis such as platelet adhesion and aggregation. Many of these are receptors.	PM-GP,Platelet Glycoprotein,Platelet Membrane Glycoprotein,PM-GPs,Platelet Glycoproteins,Glycoprotein, Platelet,Glycoprotein, Platelet Membrane,Glycoproteins, Platelet,Glycoproteins, Platelet Membrane,Membrane Glycoprotein, Platelet,Membrane Glycoproteins, Platelet,PM GP
D001862	Bone Resorption	Bone loss due to osteoclastic activity.	Bone Loss, Osteoclastic,Osteoclastic Bone Loss,Bone Losses, Osteoclastic,Bone Resorptions,Loss, Osteoclastic Bone,Losses, Osteoclastic Bone,Osteoclastic Bone Losses,Resorption, Bone,Resorptions, Bone
D002417	Cattle	Domesticated bovine animals of the genus Bos, usually kept on a farm or ranch and used for the production of meat or dairy products or for heavy labor.	Beef Cow,Bos grunniens,Bos indicus,Bos indicus Cattle,Bos taurus,Cow,Cow, Domestic,Dairy Cow,Holstein Cow,Indicine Cattle,Taurine Cattle,Taurus Cattle,Yak,Zebu,Beef Cows,Bos indicus Cattles,Cattle, Bos indicus,Cattle, Indicine,Cattle, Taurine,Cattle, Taurus,Cattles, Bos indicus,Cattles, Indicine,Cattles, Taurine,Cattles, Taurus,Cow, Beef,Cow, Dairy,Cow, Holstein,Cows,Dairy Cows,Domestic Cow,Domestic Cows,Indicine Cattles,Taurine Cattles,Taurus Cattles,Yaks,Zebus
D002448	Cell Adhesion	Adherence of cells to surfaces or to other cells.	Adhesion, Cell,Adhesions, Cell,Cell Adhesions
D003435	Crotalid Venoms	Venoms from snakes of the subfamily Crotalinae or pit vipers, found mostly in the Americas. They include the rattlesnake, cottonmouth, fer-de-lance, bushmaster, and American copperhead. Their venoms contain nontoxic proteins, cardio-, hemo-, cyto-, and neurotoxins, and many enzymes, especially phospholipases A. Many of the toxins have been characterized.	Bothrops Venom,Crotalidae Venoms,Pit Viper Venoms,Rattlesnake Venoms,Crotactin,Crotalid Venom,Crotalin,Crotaline Snake Venom,Crotalotoxin,Crotamin,Pit Viper Venom,Rattlesnake Venom,Snake Venom, Crotaline,Venom, Bothrops,Venom, Crotalid,Venom, Crotaline Snake,Venom, Pit Viper,Venom, Rattlesnake,Venoms, Crotalid,Venoms, Crotalidae,Venoms, Pit Viper,Venoms, Rattlesnake,Viper Venom, Pit
D005109	Extracellular Matrix	A meshwork-like substance found within the extracellular space and in association with the basement membrane of the cell surface. It promotes cellular proliferation and provides a supporting structure to which cells or cell lysates in culture dishes adhere.	Matrix, Extracellular,Extracellular Matrices,Matrices, Extracellular
D005312	Fetal Blood	Blood of the fetus. Exchange of nutrients and waste between the fetal and maternal blood occurs via the PLACENTA. The cord blood is blood contained in the umbilical vessels (UMBILICAL CORD) at the time of delivery.	Cord Blood,Umbilical Cord Blood,Blood, Cord,Blood, Fetal,Blood, Umbilical Cord,Bloods, Cord,Bloods, Fetal,Bloods, Umbilical Cord,Cord Blood, Umbilical,Cord Bloods,Cord Bloods, Umbilical,Fetal Bloods,Umbilical Cord Bloods