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Production and release of matrix vesicles in the cell processes of TPA‐treated human osteoblast‐like cells
Author(s) -
RingbomAnderson Tove,
Jäntti Jussi,
Åkerman Karl E.O.
Publication year - 1994
Publication title -
journal of bone and mineral research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.882
H-Index - 241
eISSN - 1523-4681
pISSN - 0884-0431
DOI - 10.1002/jbmr.5650090511
Subject(s) - vesicle , endoplasmic reticulum , alkaline phosphatase , osteoblast , cytoplasm , chemistry , cell culture , microbiology and biotechnology , matrix (chemical analysis) , intracellular , calcium , biochemistry , biophysics , biology , membrane , in vitro , enzyme , organic chemistry , chromatography , genetics
At the onset of the mineralization of bone, small membranous matrix vesicles are often observed. The information available on the production and release of these vesicles is limited. When treated with 10–20 nM of the phorbol ester 12‐O‐tetradecanoyl‐phorbol‐13‐acetate (TPA), the human osteosarcoma cell line U‐2 OS developed long cytoplasmic processes connecting adjacent cells. SEM and TEM show that TPA triggers a production and release of matrix vesicle‐like membrane vesicles, mainly from the cellular processes. Tetracycline HC1 was used to label intracellular bound calcium. The tetracycline HC1 label was primarily localized to the end‐feet of the cytoplasmic processes, indicating that these contain high concentrations of Ca 2+ , and to endoplasmic reticulum‐like structures in the cell bodies. Together with our previous demonstration of the release of alkaline phosphatase‐containing vesicles into the culture medium (Ringbom‐Anderson T, Åkerman KEO 1992 Calcif Tissue Int 50:533–540), the results presented here indicate that TPA induces a rapid induction of the primary steps of mineralization in U‐2 OS osteosarcoma.