English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Tools annual

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools monthly

Global: Zendy Plus monthly

Presents the access of premium content as premium feature

Premium Content

Global: Zendy Plus annual

Global: Zendy Free Plan

Thrombospondin (TSP) binds to U937 monocytic cells in a Ca2(+)-enhancible and EDTA-inhibitable manner (Silverstein, R. L., and R. L. Nachman. 1987. J. Clin. Invest. 79:867-874; Silverstein, R. L., A. S. Asch, and R. L. Nachman. 1989. J. Clin. Invest. 84:546-552). We reproduced the results when RPMI cell culture medium, but not when HBSS was used as binding medium. Addition of 1 mM Ca2+ to RPMI medium increased the binding of TSP to suspended U937 cells more than eightfold; the increase was blocked by EDTA but not by heparin. Further studies showed that addition of 1 mM Ca2+ to RPMI medium resulted in an insoluble precipitate, which did not form when EDTA was present or when 1 mM extra Ca2+ was added to HBSS. TSP bound to the precipitate in a saturable and specific manner. The precipitate enhanced binding of TSP to MG63 osteosarcoma cells in a monolayer binding assay. Enhancement of binding in the monolayer assay was observed for fibronectin and vitronectin as well. Our data indicate that there is not a specific Ca2(+)-dependent TSP receptor on U937 cell surface. Instead, the extra binding enhanced by Ca2+ is due to the formation of insoluble salts in the medium.

Ca2(+)-sensitive binding of thrombospondin to U937 cells is due to the formation of calcium precipitate in the binding medium.