Maeda K, Taniguchi H, Ohno I, Ohtsu H, Yamauchi K, Sakurai E, Tanno Y, Butterfield J H, Watanabe T, Shirato K
First Department of Internal Medicine, Tohoku University School of Medicine, Sendai, Japan.
Exp Hematol. 1998 Apr;26(4):325-31.
Histamine is an important mediator in allergic reactions, gastric acid secretions, and neurotransmission in the central nervous system. Basophils and mast cells are the main sources of histamine, which is formed from L-histidine by histidine decarboxylase (HDC). However, the regulatory mechanism of HDC in these cells remains unclear. We examined the regulation of HDC activity and gene expression using a unique human mast cell line, HMC-1, after stimulation with phorbol 12-myristate 13-acetate (PMA) or ionomycin. HDC activity was increased from 52.1+/-0.4 (mean+/-standard deviation) to 154+/-6.9, or 105.6+/-6.2 pmol/min/mg protein (n = 3), 4 hours after stimulation with PMA (10 ng/mL) or ionomycin (10[-6] M). Although actinomycin D had no effect on this increase, cycloheximide completely inhibited the increase caused by these stimuli. The population of HMC-1 cells containing HDC protein was increased after stimulation with either PMA or ionomycin as evaluated by immunocytochemical analysis with anti-HDC antibody as a marker. HMC-1 constitutively expressed HDC mRNA, and its level was not increased with these stimuli. These results suggest that the increase of HDC activity in HMC-1 induced by PMA or ionomycin is regulated at the translational level.
组胺是过敏反应、胃酸分泌及中枢神经系统神经传递中的一种重要介质。嗜碱性粒细胞和肥大细胞是组胺的主要来源，组胺由组氨酸脱羧酶（HDC）作用于L-组氨酸形成。然而，HDC在这些细胞中的调节机制仍不清楚。我们使用独特的人肥大细胞系HMC-1，在用佛波酯12-肉豆蔻酸酯13-乙酸酯（PMA）或离子霉素刺激后，研究了HDC活性和基因表达的调节情况。用PMA（10 ng/mL）或离子霉素（10[-6] M）刺激4小时后，HDC活性从52.1±0.4（平均值±标准差）增加到154±6.9或105.6±6.2 pmol/分钟/毫克蛋白质（n = 3）。虽然放线菌素D对这种增加没有影响，但放线菌酮完全抑制了这些刺激所引起的增加。以抗HDC抗体作为标志物，通过免疫细胞化学分析评估，用PMA或离子霉素刺激后，含有HDC蛋白的HMC-1细胞数量增加。HMC-1组成性表达HDC mRNA，其水平在这些刺激下并未升高。这些结果表明，PMA或离子霉素诱导的HMC-1中HDC活性的增加是在翻译水平上受到调节的。
