Expression of functional NK-1 receptors in murine microglia.
Cells of myeloid origin such as microglia have the potential to contribute significantly to the development of inflammatory responses in the CNS. The ability of the neuropeptide substance P to augment proinflammatory responses by other myeloid cell types such as macrophages and dendritic cells is well recognized. In the present study, we demonstrate the presence of mRNA encoding NK-1 (substance P) receptors in murine microglia cell lines. Importantly, we have utilized specific antibodies developed by our laboratory to detect the expression of the NK-1 receptor protein in murine microglia cell lines by Western blot analysis and flow cytometry. Furthermore, we have investigated the presence of this receptor on primary murine microglia and report the presence of authentic NK-1 receptors as determined by Western blot analysis and flow cytometry. In addition, we demonstrate that NK-1 receptors expressed on microglia are functional as demonstrated by the ability of nanomolar concentrations of substance P to initiate activation of the transcriptional activator, NF-kappaB. Given the weight of evidence supporting the role of substance P--substance P receptor interactions in the initiation of optimal proinflammatory responses by myeloid cells, the demonstration of authentic and functional NK-1 receptors in microglia identifies this neuropeptide as a potentially important contributor to CNS inflammatory responses during disease states.
Rasley
Amy
A
Department of Biology, University of North Carolina at Charlotte, Charlotte, North Carolina 28223, USA.
Bost
Kenneth L
KL
Olson
Julie K
JK
Miller
Stephen D
SD
Marriott
Ian
I
D000818:Animals; D000831:Animals, Newborn; D000943:Antigens, Differentiation / Q000378:metabolism; D015415:Biomarkers; D001921:Brain / Q000166:cytology / Q000276:immunology / Q000378:metabolism*; D018845:CD11 Antigens / Q000378:metabolism; D002478:Cells, Cultured; D016207:Cytokines / Q000096:biosynthesis / Q000276:immunology; D004660:Encephalitis / Q000276:immunology / Q000378:metabolism* / Q000503:physiopathology; D005455:Fluorescent Antibody Technique; D005786:Gene Expression Regulation / Q000187:drug effects / Q000276:immunology; D005911:Gliosis / Q000276:immunology / Q000378:metabolism* / Q000503:physiopathology; D051379:Mice; D008807:Mice, Inbred BALB C; D017628:Microglia / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D016328:NF-kappa B / Q000187:drug effects / Q000276:immunology / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism; D018040:Receptors, Neurokinin-1 / Q000187:drug effects / Q000235:genetics / Q000378:metabolism*; D013373:Substance P / Q000378:metabolism* / Q000494:pharmacology; D015854:Up-Regulation / Q000187:drug effects / Q000276:immunology
D000943:Antigens, Differentiation; D015415:Biomarkers; D018845:CD11 Antigens; D016207:Cytokines; D016328:NF-kappa B; D012333:RNA, Messenger; D018040:Receptors, Neurokinin-1; C036763:monocyte-macrophage differentiation antigen; D013373:Substance P