Catalogo Articoli (Spogli Riviste)

OPAC HELP

Titolo:
Apoptosis may determine the release of skeletal alkaline phosphatase activity from human osteoblast-line cells
Autore:
Farley, JR; Stilt-Coffing, B;
Indirizzi:
Loma Linda Univ, Dept Med, Loma Linda, CA 92357 USA Loma Linda Univ Loma Linda CA USA 92357 ept Med, Loma Linda, CA 92357 USA Loma Linda Univ, Dept Biochem, Loma Linda, CA 92357 USA Loma Linda Univ Loma Linda CA USA 92357 Biochem, Loma Linda, CA 92357 USA Jerry L Pettis Mem Vet Adm Med Ctr, Loma Linda, CA 92357 USA Jerry L Pettis Mem Vet Adm Med Ctr Loma Linda CA USA 92357 , CA 92357 USA
Titolo Testata:
CALCIFIED TISSUE INTERNATIONAL
fascicolo: 1, volume: 68, anno: 2001,
pagine: 43 - 52
SICI:
0171-967X(200101)68:1<43:AMDTRO>2.0.ZU;2-K
Fonte:
ISI
Lingua:
ENG
Soggetto:
BONE-FORMATION; PHOSPHOLIPASE-D; GROWTH-FACTORS; 3-THYMIDINE INCORPORATION; INFANTILE HYPOPHOSPHATASIA; ENDOCHONDRAL OSSIFICATION; CHONDROCYTE APOPTOSIS; INVITRO EVIDENCE; DEATH APOPTOSIS; SAOS-2;
Keywords:
sALP; SaOS(2); apoptosis; TNF-alpha; okadiac acid;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Life Sciences
Citazioni:
61
Recensione:
Indirizzi per estratti:
Indirizzo: Farley, JR Loma Linda Univ, Dept Med, 11201 Benton St, Loma Linda, CA 92357 USA Loma Linda Univ 11201 Benton St Loma Linda CA USA 92357 357 USA
Citazione:
J.R. Farley e B. Stilt-Coffing, "Apoptosis may determine the release of skeletal alkaline phosphatase activity from human osteoblast-line cells", CALCIF TIS, 68(1), 2001, pp. 43-52

Abstract

Although quantitative measurement of skeletal alkaline phosphatase (sALP) activity in serum can provide an index of the rate of bone formation, the metabolic process that determines the release of sALP - from the surface of osteoblasts, into circulation-is unknown. The current studies were intendedto examine the hypothesis that the release of sALP from human osteoblasts is a consequence of apoptotic cell death. We measured the release of sALP activity from human osteosarcoma (SaOS-2) cells and normal human bone cells,under basal conditions and in response to agents that increased apoptosis (TNF-alpha, okadiac acid) and agents that inhibit apoptosis (IGF-I, calpain, and caspase inhibitors). Apoptosis was determined by the presence of nucleosomes (histone-associated DNA) in the cytoplasm of the cells by using a commercial kit. The results of these studies showed that TNF-alpha and okadiac acid caused dose- and time-dependent increases in apoptosis in the SaOS-2 cells (r = 0.78 for doses of TNF-alpha and r = 0.93 for doses of okadiac acid, P < 0.005 for each), with associated decreases in cell layer protein (P < 0.05 for each) and concomitant increases in the release of sALP activity (e.g., r = 0.89 for TNF-alpha and r = 0.75 for okadiac acid, P < 0.001 for each). In contrast, caspase and calpain inhibitors reduced apoptosis, increased cell layer protein, and decreased the release of sALP activity (P <0.05 for each). Exposure to IGF-I also decreased apoptosis, in a time- anddose-dependent manner (e.g., r = 0.93, P < 0.001 for IGF-I doses), with associated proportional effects to increase cell layer protein (P < 0.001) and decrease the release of sALP activity (P < 0.001). TGF-I also inhibited the actions of TNF-a and okadiac acid to increase apoptosis and sALP release. The associations between apoptosis and sALP re lease were not unique to osteosarcoma (i.e., SaOS-2) cells, but also seen with osteoblast-line cells derived from normal human bone. Together, these data demonstrate that the release of sALP activity from human osteoblast-line cells in vitro is associated with, and may be a consequence of, apoptotic cell death. These findings are consistent with the general hypothesis that the appearance of sALP activity in serum may reflect the turnover of osteoblast-line cells.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 30/09/20 alle ore 09:18:39