Title
Human osteoblasts produce cathepsin K
Author
Mandelin, J.
Hukkanen, M.
Li, T.F.
Korhonen, M.
Liljeström, M.
Sillat, T.
Hanemaaijer, R.
Salo, J.
Santavirta, S.
Konttinen, Y.T.
TNO Kwaliteit van Leven
Publication year
2006
Abstract
Healthy bone is a rigid yet living tissue that undergoes continuous remodeling. Osteoclasts resorb bone in the remodeling cycle. They secrete H+-ions and proteinases to dissolve bone mineral and degrade organic bone matrix, respectively. One of the main collagenolytic proteinase in osteoclasts is cathepsin K, a member of papain family cysteine proteinases. Recently, it has been shown that osteoblasts may contribute to organic matrix remodeling. We therefore investigated their ability to produce cathepsin K for this action. Trabecular bone samples were collected from patients operated due to a fracture of the femoral neck. Part of the bone was decalcified and the rest was used for cell isolation. Sections from the decalcified bone were immunostained with antibodies against cathepsin K. Isolated cells were characterized for their ability to form mineralized matrix and subsequently analyzed for their cathepsin K production by Western blotting and quantitative RT-PCR. Osteoblasts, bone lining cells and some osteocytes in situ showed cathepsin K immunoreactivity and osteoblast-like cells in vitro produced cathepsin K mRNA and released both 42 kDa pro- and 27 kDa processed cathepsin K to culture media. Osteoblastic cathepsin K may thus contribute to collagenous matrix maintenance and recycling of improperly processed collagen I. Whether osteoblastic cathepsin K synthesis has consequences in diseases characterized by abnormal bone matrix turnover remains to be investigated. © 2006. Chemicals / CAS: cathepsin K, 94716-09-3; Alkaline Phosphatase, EC 3.1.3.1; cathepsin K, EC 3.4.22.-; Cathepsins, EC 3.4.-; Core Binding Factor Alpha 1 Subunit; Matrix Metalloproteinase 13, EC 3.4.24.-; Osteoprotegerin; RANK Ligand; RNA, Messenger; RUNX2 protein, human; TNFSF11 protein, human; Tumor Necrosis Factor-alpha
Subject
Biomedical Research
Cathepsin K
Cytokines
Osteoblasts
Osteoporosis
Stromal cells
antibody
cathepsin K
collagen type 1
messenger RNA
bone matrix
cell isolation
controlled study
culture medium
femur neck
fracture
human
human cell
human tissue
immunoassay
immunohistochemistry
immunoreactivity
nucleotide sequence
osteoblast
osteocyte
protein analysis
protein function
protein secretion
protein synthesis
quantitative analysis
reverse transcription polymerase chain reaction
RNA analysis
sampling
trabecular bone
Western blotting
Alkaline Phosphatase
Calcification, Physiologic
Cathepsins
Cell Differentiation
Cells, Cultured
Core Binding Factor Alpha 1 Subunit
Gene Expression Regulation
Humans
Immunohistochemistry
Matrix Metalloproteinase 13
Mesenchymal Stem Cells
Osteoclasts
Osteoprotegerin
RANK Ligand
RNA, Messenger
Tumor Necrosis Factor-alpha
To reference this document use:
http://resolver.tudelft.nl/uuid:5afa6ee7-4bab-4513-9232-aadbf85420bf
DOI
https://doi.org/10.1016/j.bone.2005.10.017
TNO identifier
239276
ISSN
8756-3282
Source
Bone, 38 (6), 769-777
Document type
article