HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Free Full Text (PDF) Free Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Huang, Z. L. Articles by Reeves, P. G. Search for Related Content PubMed PubMed Citation Articles by Huang, Z. L. Articles by Reeves, P. G.

---

ORIGINAL ARTICLE

Differentiation of Human U937 Promonocytic Cells Is Impaired by Moderate Copper Deficiency

Zhixin L. Huang^*, Mark L. Failla^*,1 and Philip G. Reeves

^* Graduate Program in Nutrition, The University of North Carolina at Greensboro, Greensboro, North Carolina 27402; and
United States Department of Agriculture, Agricultural Research Service, Grand Forks Human Nutrition Research Center, GrandForks,NorthDakota58203

Copper (Cu) deficiency suppresses macrophage activities in animals and humans. Our previous studies indicated that the induction of Cu deficiency in differentiated U937 monocytic cells impairs respiratory burst and bactericidal activities and lipopolysaccharide-mediated secretion of inflammatory mediators. The current investigation examined the roles of Cu in the monocytic differentiation process. Human U937 promonocytic cells were exposed to a high affinity Cu chelator (5 µM 2,3,2-tetraamine [tet]) for 24 hr before inducing differentiation by treatment with 1,25-dihydroxyvitamin D₃ plus interferon- (DI). This procedure decreased cell Cu by 55% without compromising cellular Zn, Fe, or general metabolic activities. Lower Cu status significantly attenuated the expression of maturation markers Mac-1 (CD11b), ICAM-1 (CD54), and LPS-R (CD14). This change was associated with a marked suppression in respiratory burst activity and killing of Salmonella. To examine if the adverse effect of inadequate Cu on the DI-induced differentiation represented a more general defect, U937 cells were treated with phorbol 12-myristate 13-acetate (PMA). Lower Cu status also suppressed PMA-mediated differentiation of U937 cells. Supplemental Cu, but not Zn or Fe, blocked the tet-induced declines in cell Cu, expression of maturation markers, and respiratory burst and bactericidal activities. These results demonstrate that Cu is essential for the monocytic differentiation process that contributes to the competency of the host's defense system.

Key Words: copper • cell differentiation • monocytes • U937 cells

This article has been cited by other articles:

				Z. L. Huang and P. J. Fraker Chronic Consumption of a Moderately Low Protein Diet Does Not Alter Hematopoietic Processes in Young Adult Mice J. Nutr., May 1, 2003; 133(5): 1403 - 1408. [Abstract] [Full Text] [PDF]