Tang Y, Feng Y, Wang X
Institute of Vascular Medicine, The Third Hospital, Beijing Medical University, China.
J Neuroimmunol. 1998 Apr 15;84(2):207-12. doi: 10.1016/s0165-5728(97)00257-9.
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.
巨噬细胞受到刺激后白细胞介素-6（IL-6）的分泌，已被发现参与防御机制、造血和急性期反应的调节，发挥核心作用。据报道，环磷酸腺苷（cAMP）参与IL-6产生的调节。由于已知降钙素基因相关肽（CGRP）可增加小鼠巨噬细胞中cAMP的积累，我们研究了CGRP是否会诱导巨噬细胞释放IL-6。巨噬细胞取自雄性Balb/c小鼠的腹腔渗出液。将细胞以每孔2.5×10⁵个细胞的密度接种于培养皿中，使其贴壁2小时。在用PRMI-1640换液培养48小时后，将巨噬细胞与1微克/毫升的CGRP和脂多糖（LPS）一起培养12小时。用酶联免疫吸附测定（ELISA）试剂盒测量培养基中的IL-6水平。结果表明，CGRP对IL-6的产生没有直接影响，但它以浓度依赖的方式增强LPS诱导的IL-6产生。当CGRP浓度为10⁻¹⁰摩尔时，LPS诱导的IL-6产生从5.16±0.48纳克/毫升增加到8.88±0.48纳克/毫升。CGRP 10⁻¹⁰摩尔的作用被CGRP1受体拮抗剂hCGRP(8 - 37) 10⁻⁸摩尔逆转。腺苷酸环化酶激活剂5微摩尔的福斯可林也增强了LPS诱导的巨噬细胞IL-6产生。此外，用1微摩尔的H - 89或100微摩尔的Rp - cAMPS（cAMP依赖性蛋白激酶抑制剂）预处理，分别抑制了CGRP作用的31%和98%。这些结果表明，在小鼠常驻腹腔巨噬细胞中，CGRP通过激活cAMP途径增强LPS诱导的IL-6释放。
