Murakami M, Tada K, Shimbara S, Kambe T, Sawada H, Kudo I
Department of Health Chemistry, School of Pharmaceutical Sciences, Showa University, Tokyo, Japan.
FEBS Lett. 1997 Aug 18;413(2):249-54. doi: 10.1016/s0014-5793(97)00916-2.
We previously reported that BALB/cJ mouse-derived bone marrow-derived mast cells (BMMC) exhibited two sequential phases of prostaglandin D2 (PGD2) generation in response to Fc(epsilon) receptor I (Fc(epsilon)RI) crosslinking and cytokine stimulation, the late phase of which was suppressed by an antibody raised against type IIA secretory phospholipase A2 (sPLA2). Here we report that BMMC derived from C57BL/6J mice, which are genetically deficient in type IIA sPLA2, display both immediate and delayed PGD2 generation normally. Lysates of C57BL/6J-derived BMMC contained a Ca2+-dependent PLA2 that was absorbed to a column conjugated with anti-type IIA sPLA2 antibody and had a similar molecular mass of 14 kDa, as assessed by immunoblotting. Therefore we speculate that a sPLA2 similar to, but distinct from, type IIA sPLA2 would compensate for type IIA sPLA2 deficiency in C57BL/6J-derived BMMC. We found that the two type IIA-related sPLA2 family members, type V and type IIC sPLA2s, were expressed in BMMC as well as in rat mastocytoma RBL-2H3 cells.
我们之前报道过，源自BALB/cJ小鼠的骨髓来源肥大细胞（BMMC）在受到Fc(ε)受体I（Fc(ε)RI）交联和细胞因子刺激时，会呈现出前列腺素D2（PGD2）生成的两个连续阶段，其中晚期阶段会被一种针对IIA型分泌型磷脂酶A2（sPLA2）的抗体所抑制。在此我们报道，源自C57BL/6J小鼠（其在基因上缺乏IIA型sPLA2）的BMMC能够正常呈现即时和延迟的PGD2生成。源自C57BL/6J的BMMC的裂解物含有一种钙依赖性磷脂酶A2，该酶可被吸附到与抗IIA型sPLA2抗体偶联的柱子上，并且通过免疫印迹评估，其分子量与14 kDa相似。因此我们推测，一种与IIA型sPLA2相似但又不同的sPLA2会补偿源自C57BL/6J的BMMC中IIA型sPLA2的缺乏。我们发现，两种与IIA型相关的sPLA2家族成员，即V型和IIC型sPLA2，在BMMC以及大鼠肥大细胞瘤RBL-2H3细胞中均有表达。
