Calcitonin gene-related peptide potentiates LPS-induced IL-6 release from mouse peritoneal macrophages.
The secretion of IL-6 after stimulation of macrophages has been found to play a central role in the regulation of defense mechanism, haematopoiesis, and acute phase reaction. It was reported that cAMP is involved in the regulation of IL-6 production. Since calcitonin gene-related peptide (CGRP) is known to increase cAMP accumulation in mouse macrophages, we examined whether CGRP would induce IL-6 release in macrophages. Macrophages were obtained from the peritoneal exudate of male Balb/c mouse. The cells were plated on culture dishes at a density of 2.5 x 10(5) cells per well and allowed to adhere for 2 h. After incubation for 48 h with two changes of PRMI-1640, the macrophages were cultured with CGRP and LPS 1 microg/ml for 12 h. The IL-6 level in medium was measured by ELISA kits. The results showed that CGRP had no direct effects on IL-6 production, but it potentiated LPS-induced IL-6 production in a concentration-dependent manner. When CGRP was at a concentration of 10(-10) M, the LPS-induced IL-6 production was increased from 5.16 +/- 0.48 to 8.88 +/- 0.48 ng/ml. The effect of CGRP 10(-10) M was reversed by hCGRP(8-37) 10(-8) M, an antagonist of CGRP1 receptor. The LPS-induced IL-6 production from macrophages was also potentiated by forskolin 5 microM, an activator of adenylate cyclase. Furthermore, pretreatment with H-89 1 microM or Rp-cAMPS 100 microM, the inhibitors of cAMP-dependent protein kinase, inhibited the effect of CGRP by 31% and 98%, respectively. These results demonstrate that the LPS-induced IL-6 release is potentiated by CGRP via the activation of cAMP pathway in mouse resident peritoneal macrophages.
Tang
Y
Y
Institute of Vascular Medicine, The Third Hospital, Beijing Medical University, China.
Feng
Y
Y
Wang
X
X
D000818:Animals; D015740:Calcitonin Gene-Related Peptide / Q000276:immunology* / Q000494:pharmacology; D000242:Cyclic AMP / Q000031:analogs & derivatives / Q000494:pharmacology; D017868:Cyclic AMP-Dependent Protein Kinases / Q000037:antagonists & inhibitors / Q000378:metabolism; D004357:Drug Synergism; D004791:Enzyme Inhibitors / Q000494:pharmacology; D015850:Interleukin-6 / Q000378:metabolism*; D007546:Isoquinolines / Q000494:pharmacology; D008070:Lipopolysaccharides / Q000494:pharmacology*; D008213:Lymphocyte Activation / Q000187:drug effects; D017737:Macrophages, Peritoneal / Q000737:chemistry / Q000187:drug effects* / Q000201:enzymology; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D008916:Miotics / Q000276:immunology / Q000494:pharmacology*; D010446:Peptide Fragments / Q000276:immunology* / Q000494:pharmacology; D018015:Receptors, Calcitonin Gene-Related Peptide / Q000276:immunology; D013449:Sulfonamides; D013873:Thionucleotides / Q000494:pharmacology
D004791:Enzyme Inhibitors; D015850:Interleukin-6; D007546:Isoquinolines; D008070:Lipopolysaccharides; D008916:Miotics; D010446:Peptide Fragments; D018015:Receptors, Calcitonin Gene-Related Peptide; D013449:Sulfonamides; D013873:Thionucleotides; C058636:calcitonin gene-related peptide (8-37); C016957:adenosine-3',5'-cyclic phosphorothioate; D000242:Cyclic AMP; D017868:Cyclic AMP-Dependent Protein Kinases; D015740:Calcitonin Gene-Related Peptide; C063509:N-(2-(4-bromocinnamylamino)ethyl)-5-isoquinolinesulfonamide