Detection of substance P and its receptor in human fetal microglia.
Substance P, the most abundant neurokinin in the CNS, is a major modulator of the immune system. We have examined the gene expression of substance P and its receptor in human fetal brain microglia. Using reverse transcription-polymerase chain reaction and Southern blotting assay, the four isoforms of preprotachykinin-A gene transcripts (alpha, beta, gamma and delta) were detected in the microglia. The human fetal microglia produced significantly higher levels of endogenous substance P protein (640-850 pg/10(6) cells) than did human peripheral blood monocyte-derived macrophages (25-50 pg/10(6) cells), as determined by an enzyme immunoassay. Using immunohistochemical staining with an anti-substance P antibody, cell membrane substance P immunoreactivity was observed. In addition, we identified the presence of messenger RNA for neurokinin-1 receptor, a primary receptor for substance P in human fetal microglia.From these data, we propose that substance P and its receptor are biologically involved in regulating the functions of microglia, and potentially play an important role in host defense of the central nervous system.
Lai
J P
JP
Division of Immunologic and Infectious Diseases, Joseph Stokes Jr. Research Institute at The Children's Hospital of Philadelphia, Department of Pediatrics, University of Pennsylvania School of Medicine, Philadelphia 19104, USA.
Zhan
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Campbell
D E
DE
Douglas
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Ho
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WZ
D001921:Brain / Q000166:cytology / Q000196:embryology*; D002478:Cells, Cultured; D005333:Fetus / Q000378:metabolism; D015870:Gene Expression; D006801:Humans; D007150:Immunohistochemistry / Q000379:methods; D008264:Macrophages / Q000378:metabolism; D017628:Microglia / Q000378:metabolism*; D011498:Protein Precursors / Q000235:genetics; D012333:RNA, Messenger / Q000378:metabolism; D018040:Receptors, Neurokinin-1 / Q000235:genetics / Q000378:metabolism*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013194:Staining and Labeling; D013373:Substance P / Q000378:metabolism*; D015320:Tachykinins / Q000235:genetics
D011498:Protein Precursors; D012333:RNA, Messenger; D018040:Receptors, Neurokinin-1; D015320:Tachykinins; C044206:preprotachykinin; D013373:Substance P