Role of zinc trensporter in allergic reaction

锌（Zn）是一种必需的营养素，它的缺乏会导致免疫缺陷。电镜观察显示肥大细胞颗粒富含锌。然而，锌在肥大细胞中的确切作用和分子机制尚未阐明。一般认为，锌是通过锌转运蛋白向颗粒细胞供应的。结果表明，锌转运蛋白ZnT 2/Slc 30 a2定位于肥大细胞的颗粒膜上。为了了解颗粒锌在肥大细胞中的作用，我们制备了ZnT 2-KO小鼠。我们发现ZnT 2基因敲除小鼠盲肠结扎和穿孔后存活率降低，有报道称锌是肥大细胞中CPA 3（carboxypeptidase 3，羧肽酶3）活性所必需的，CPA 3活性的丧失导致内皮素诱导的脓毒症休克。与该报告一致，在ZnT 2-KO肥大细胞中CPA 3活性降低。在这项研究中，我们发现ZnT 2对于脓毒症的存活是重要的，并且是锌依赖性CPA 3活性所必需的。

Zinc (Zn) is an essential nutrient and its deficiency causes immunodeficiency. Electron microscopic studies demonstrated that mast cell granules are rich in Zn. However, the precise roles and molecular mechanism(s) of Zn`s function in mast cells have not been clarified. It has been considered that Zn is supplied to granule by Zn transporter. We identified that Zn transporter ZnT2/Slc30a2 was localized at granule membrane in mast cell. To understand role of granule`s Zn in mast cell, we generated ZnT2-KO mice. We found that survival rate in cecal ligation and puncture was diminished in ZnT2-KO mice.It has reported Zn is required for activity of CPA3 (carboxypeptidase3) in mast cell and loss of CPA3 activity causes endothelin-induced sepsis shock. Consistent with this report, CPA3 activity was decreased in ZnT2-KO mast cell. In this study, we showed that ZnT2 is important for survival from sepsis and required for Zn-dependent CPA3 activity.