Expression of substance P and its neurokinin-1 receptor on thymocytes: functional relevance in the regulation of thymocyte apoptosis and proliferation.
Herein, we provide evidence of the expression and function of substance P (SP) and neurokinin-1 receptor (NK-1R) in the rat thymus. In situ hybridization evidenced NK-1R mRNA mainly in the thymic medulla, and Northern blot analysis of mRNA from FACS-sorted thymocytes identified NK-1R on CD4+, CD8+ and double-positive subpopulations. With flow cytometry, it could be seen that NK-1R was expressed on the majority of CD5+ thymocytes, and it was identified by Western blot analysis as two bands migrating at 44 and 54 kD. SP administration rescues thymocytes from spontaneous and NK-1R antagonist (SR140333)-induced apoptosis and stimulates concanavalin A (ConA)-induced thymocyte proliferation, CD25 expression and IL-2 production, whereas SR140333 exerts inhibitory effects on these functions. We also demonstrated the expression of mRNA for the SP precursor preprotachykinin-A in the thymic medulla and purified CD5+ thymocytes. SP protein was detected on 40% of CD5+ thymocytes and identified as a band of 1.3 kD by Western blot analysis. Finally, thymocytes spontaneously released SP, which was increased upon ConA or CD3 stimulation.
Santoni
Giorgio
G
Department of Pharmacological Sciences and Experimental Medicine, University of Camerino, Camerino, Italy. giorgio.santoni@unicam.it
Amantini
Consuelo
C
Lucciarini
Roberta
R
Pompei
Pierluigi
P
Perfumi
Marina
M
Nabissi
Massimo
M
Morrone
Stefania
S
Piccoli
Mario
M
D000818:Animals; D017209:Apoptosis / Q000187:drug effects / Q000276:immunology*; D018956:CD5 Antigens / Q000276:immunology; D002455:Cell Division / Q000187:drug effects / Q000276:immunology*; D002478:Cells, Cultured; D004347:Drug Interactions / Q000502:physiology; D006706:Homeostasis / Q000276:immunology; D007376:Interleukin-2 / Q000378:metabolism; D053645:Interleukin-2 Receptor alpha Subunit; D008297:Male; D015213:Neuroimmunomodulation / Q000187:drug effects / Q000276:immunology*; D064729:Neurokinin-1 Receptor Antagonists; D010880:Piperidines / Q000494:pharmacology; D011498:Protein Precursors / Q000378:metabolism; D011812:Quinuclidines / Q000494:pharmacology; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D018123:Receptors, Interleukin / Q000187:drug effects / Q000378:metabolism; D018040:Receptors, Neurokinin-1 / Q000235:genetics / Q000276:immunology*; D013373:Substance P / Q000276:immunology* / Q000378:metabolism / Q000494:pharmacology; D013601:T-Lymphocytes / Q000187:drug effects / Q000276:immunology* / Q000378:metabolism; D015320:Tachykinins / Q000378:metabolism; D013950:Thymus Gland / Q000166:cytology / Q000254:growth & development / Q000276:immunology*
D018956:CD5 Antigens; D007376:Interleukin-2; D053645:Interleukin-2 Receptor alpha Subunit; D064729:Neurokinin-1 Receptor Antagonists; D010880:Piperidines; D011498:Protein Precursors; D011812:Quinuclidines; D012333:RNA, Messenger; D018123:Receptors, Interleukin; D018040:Receptors, Neurokinin-1; D015320:Tachykinins; C044206:preprotachykinin; C085215:SR 140333; D013373:Substance P