肥大细胞存在于全身的粘膜和结缔组织中。它们合成并释放各种各样的生物活性分子,比如组胺,蛋白酶,和细胞因子。在这项研究中,我们发现一群结缔组织肥大细胞(CTMC)储存和释放去甲肾上腺素,起源于交感神经.去甲肾上腺素储存细胞,不是神经元纤维,主要在皮肤的结缔组织中发现,乳腺,胃肠道,支气管,胸腺,和胰腺在野生型小鼠中,但在肥大细胞缺陷的W-sashc-kit突变体KitW-sh/W-sh小鼠中不存在。使用骨髓来源的肥大细胞的体外研究表明,细胞外去甲肾上腺素被吸收但未合成。在离子霉素刺激下,去甲肾上腺素被释放。电子显微镜分析进一步表明,去甲肾上腺素储存在肥大细胞的分泌颗粒中并从中释放。最后,我们发现储存去甲肾上腺素的CTMC表达有机阳离子转运蛋白3(Oct3),它也被称为神经外单胺转运蛋白,SLC22A3。我们的发现表明,肥大细胞可能通过在体细胞组织中储存和释放来调节去甲肾上腺素浓度。
Mast cells are present in mucosal and connective tissues throughout the body. They synthesize and release a wide variety of bioactive molecules, such as histamine, proteases, and cytokines. In this study, we found that a population of connective tissue mast cells (CTMCs) stores and releases noradrenaline, originating from sympathetic nerves. Noradrenaline-storing cells, not neuronal fibers, were predominantly identified in the connective tissues of the skin, mammary gland, gastrointestinal tract, bronchus, thymus, and pancreas in wild-type mice but were absent in mast cell-deficient W-sash c-kit mutant KitW-sh/W-sh mice. In vitro studies using bone marrow-derived mast cells revealed that extracellular noradrenaline was taken up but not synthesized. Upon ionomycin stimulation, noradrenaline was released. Electron microscopy analyses further suggested that noradrenaline is stored in and released from the secretory granules of mast cells. Finally, we found that noradrenaline-storing CTMCs express organic cation transporter 3 (Oct3), which is also known as an extraneuronal monoamine transporter, SLC22A3. Our findings indicate that mast cells may play a role in regulating noradrenaline concentration by storing and releasing it in somatic tissues.