title: Expression of cathepsin-K in gingival crevicular fluid of patients with periodontitis.
abstract: Cathepsin-K is a highly expressed cysteine protease, and it plays a key role in bone remodeling and cartilage breakdown in bone. Cathepsin-K is used as a well-known marker of osteoclast activity, because this enzyme is mainly derived from osteoclasts. The receptor activator for NF-kappaB ligand (RANKL) plays an important role in osteoclast formation. Although a recent study suggests the involvement of RANKL in the pathogenesis of periodontal disease, no one has previously examined the level of cathepsin-K in the body fluid of human subjects. If the presence of cathepsin-K, as well as RANKL, can be detected in body fluids, it would be indirect proof of the differentiation and/or activation of osteoclasts in the tissues bathed by these fluids. This communication reports on the in vivo concentrations of cathepsin-K and RANKL in the gingival crevicular fluid (GCF) of normal subjects and those patients with severe, moderate, and mild forms of the disease. Increased concentrations of cathepsin-K and RANKL were detected in the GCF from patients with periodontitis (P<0.005 versus control subjects). Also, there was a positive correlation between cathepsin-K and RANKL levels (r=0.726), suggesting that both of them contribute to osteoclastic bone destruction in periodontal disease.
authors.affiliation: Department of Medicinal Biochemistry, School of Pharmacy, Aichi-Gakuin University, Nagoya 464-8650, Japan. makio@dpc.aichi-gakuin.ac.jp
authors.forename: Makio
authors.initials: M
authors.lastname: Mogi
authors.forename: Junichi
authors.initials: J
authors.lastname: Otogoto
mesh_terms: D000328:Adult; D016723:Bone Remodeling / Q000502:physiology; D056657:Cathepsin K; D002403:Cathepsins / Q000032:analysis*; D002454:Cell Differentiation / Q000502:physiology; D003546:Cysteine Endopeptidases / Q000032:analysis*; D005883:Gingival Crevicular Fluid / Q000737:chemistry / Q000201:enzymology*; D005884:Gingival Hemorrhage / Q000201:enzymology / Q000473:pathology; D006801:Humans; D010010:Osteoclasts / Q000502:physiology; D017622:Periodontal Attachment Loss / Q000201:enzymology / Q000473:pathology; D010512:Periodontal Index; D010514:Periodontal Pocket / Q000201:enzymology / Q000473:pathology; D010518:Periodontitis / Q000201:enzymology* / Q000473:pathology; D053245:RANK Ligand / Q000032:analysis
chemical_list: D053245:RANK Ligand; D002403:Cathepsins; D003546:Cysteine Endopeptidases; C534130:CTSK protein, human; D056657:Cathepsin K