title: Differential effects of cell density on 5-lipoxygenase (5-LO), five-lipoxygenase-activating protein (FLAP) and interleukin-1 beta (IL-1 beta) expression in human neutrophils.
abstract: We have analyzed the effect of cellular density of 5-Lipoxygenase (5-LO), 5-lipoxygenase-activating protein (FLAP) and interleukin-1 beta (IL-1 beta) gene expression in neutrophils from healthy subjects under culture conditions of low and high cell density. By using RT-PCR techniques, we have found that 5-LO mRNA accumulation decreased in cells cultured at high density, while FLAP mRNA is not affected. De novo 5-LO synthesis, as well as steady-state levels, were reduced in cells maintained at high density. In contrast, the high density conditions lead to the induction of IL-1 beta gene at the RNA and protein levels as measured by RT-PCR and by immunoprecipitation. These results suggest that cellular density plays a role in gene modulation when neutrophils are accumulating at an inflammatory site since neutrophils obtained from the synovial fluid of patients with RA exhibit a protein synthesis profile similar to that observed in peripheral blood neutrophils cultured at high density.
authors.affiliation: Department of Medicine, University of North Carolina at Chapel Hill 27599, USA.
authors.forename: C
authors.initials: C
authors.lastname: Jobin
authors.forename: J
authors.initials: J
authors.lastname: Gauthier
mesh_terms: D058927:5-Lipoxygenase-Activating Proteins; D017209:Apoptosis; D001094:Arachidonate 5-Lipoxygenase / Q000235:genetics / Q000378:metabolism*; D001172:Arthritis, Rheumatoid / Q000378:metabolism / Q000473:pathology; D001483:Base Sequence; D002352:Carrier Proteins / Q000235:genetics / Q000378:metabolism*; D002452:Cell Count; D017931:DNA Primers / Q000235:genetics; D015870:Gene Expression; D006801:Humans; D066298:In Vitro Techniques; D018836:Inflammation Mediators / Q000378:metabolism; D007375:Interleukin-1 / Q000235:genetics / Q000378:metabolism*; D007700:Kinetics; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism*; D009504:Neutrophils / Q000166:cytology* / Q000378:metabolism*; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism
chemical_list: D058927:5-Lipoxygenase-Activating Proteins; C548592:ALOX5AP protein, human; D002352:Carrier Proteins; D017931:DNA Primers; D018836:Inflammation Mediators; D007375:Interleukin-1; D008565:Membrane Proteins; D012333:RNA, Messenger; D001094:Arachidonate 5-Lipoxygenase