title: Differential expression of caveolin-1 in lipopolysaccharide-activated murine macrophages.
abstract: Five reciprocal cycles of subtractive hybridization using cDNA generated from fibroblasts with normal lipopolysaccharide (LPS) responsiveness (lps(n)) and from hyporesponsive (lps(d)) fibroblasts have led to the finding that caveolin-1 is expressed at markedly higher levels of mRNA in lps(d) than in lps(n) fibroblasts. Caveolin-1 message can also be readily detected via reverse transcription-PCR in the RAW264.7 and J774.1 macrophage-like cell lines as well as in primary thioglycolate (TG)-elicited mouse peritoneal macrophages. In RAW264.7 cells, both caveolin-1 mRNA and protein levels are down-regulated by LPS. In TG-elicited C3HeB/FeJ peritoneal macrophages, in contrast, expression of both caveolin-1 protein and mRNA is up-regulated in vitro in response to LPS stimulation. The up-regulation of caveolin-1 protein expression in C3HeB/FeJ peritoneal macrophages can be demonstrated at concentrations as low as 1.0 pg of LPS/ml. However, LPS concentrations approximately 4 orders of magnitude higher (10(4) pg/ml) were required to stimulate the LPS-hyporesponsive C3H/HeJ mice peritoneal macrophages such that significant caveolin-1 protein up-regulation was detected. Caveolin-1, a principal component of plasmalemmal caveolae, has been reported as a potentially important regulator for signal transduction during cellular stimulation. The results described in this report suggest that caveolin-1 expression may be associated with LPS signaling/internalization.
authors.affiliation: Department of Microbiology, Molecular Genetics and Immunology, University of Kansas Medical Center, Kansas City, Kansas, USA. leim@umkc.edu
authors.forename: M G
authors.initials: MG
authors.lastname: Lei
authors.forename: D C
authors.initials: DC
authors.lastname: Morrison
mesh_terms: D000818:Animals; D015152:Blotting, Northern; D051242:Caveolin 1; D022461:Caveolins; D002460:Cell Line; D003001:Cloning, Molecular; D008070:Lipopolysaccharides / Q000494:pharmacology*; D008262:Macrophage Activation; D008264:Macrophages / Q000378:metabolism*; D008565:Membrane Proteins / Q000096:biosynthesis* / Q000235:genetics; D051379:Mice; D008809:Mice, Inbred C3H; D012333:RNA, Messenger / Q000032:analysis; D013864:Thioglycolates / Q000494:pharmacology
chemical_list: C495541:Cav1 protein, mouse; D051242:Caveolin 1; D022461:Caveolins; D008070:Lipopolysaccharides; D008565:Membrane Proteins; D012333:RNA, Messenger; D013864:Thioglycolates