Function of prostaglandins and histamine in proliferation and differentiation of mast cells.

建立了骨髓源性肥大细胞的原代培养体系，通过检测组氨酸脱羧酶(HDC)、PG合成酶和PG受体的表达来检测组胺和PGs的功能。我们发现，抗原-LGE复合体的刺激增加了COX-2、EP受体、IP和DP受体的表达。此外，我们阐明了HDC的细胞内定位和跨国修饰后的关系；该酶受蛋白酶体降解系统的高度调控。从这些研究中我们发现，组胺和PGs的产生以及PG受体的诱导高度依赖于肥大细胞的分化。这些结果还提示组胺和PGs可能参与肥大细胞的分化特异性过程。基于上述发现，我们利用PG受体缺陷小鼠和HDC缺陷小鼠，研究了PGs和组胺在包括肥大细胞功能在内的不同系统中的生理作用。我们建立了…通过检测每个基因敲除小鼠的表型，发现了更多缺乏每种类型前列腺素受体的ED小鼠，并阐明了前列腺素的生理作用：FP缺陷小鼠由于卵巢中孕酮的持续产生而无法分娩，表明PGF2α在正常分娩所需的黄体溶解中发挥了作用。IP缺陷小鼠血栓形成倾向增加，炎症反应减弱，未见醋酸扭体反应，提示PGI2参与了炎症和痛觉的促进作用。EP3缺陷小鼠对内源性和外源性热原均不表现出发热反应；PGE2通过EP3介导热原诱导的发热产生。EP4基因缺陷小鼠因动脉导管通畅而在出生后3天内死亡。PGE2通过EP4在新生儿动脉导管闭合中起重要作用。EP2基因缺陷的雌性小鼠由于排卵和受精障碍而表现出生育力下降；PGE2通过刺激EP2刺激卵丘扩张和由此导致的cAMP水平增加而促进排卵和受精。通过这些研究，我们证明了受体亚型特异性活性的重要性。HDC基因缺陷小鼠对IgE依赖型L过敏反应减弱，提示组胺在本病中起重要作用。较少

We established primary culture system of bone marrow-derived mast cells, and examined function of histamine and PGs by monitoring expression of histidine decarboxylase(HDC), PG synthetases, and PG receptors. We found that stimulation of antigen-lgE complexes increase expression of COX-2, EP receptors, IP and DP receptors. In addition, we clarified relationship between intracellular localization of HDC and post-transnational modification; this enzyme is highly-regulated by the proteasome degradation system. From these studies, we found that production of histamine and PGs, and induction of PG receptors are highly-regulated dependent on differentiation of mast cells. These results also suggested that histamine and PGs may take part in differentiation-specific processes of mast cells.Based on findings described above, we examined physiological roles of PGs and histamine in various systems including mast cell function by using PG receptor-deficient mice and HDC-deficient mice. We establish … More ed mice deficient in each type of prostanoid receptors, and clarified physiological roles of prostanoids by examining phenotypes in each knockout mice : FP-deficient mice fail to deliver their pups due to persistent production of progesterone in ovaries, indicating that PGF2α plays a role in luteolysis required for normal parturition. IP-deficient mice showed increased tendency of thrombosis, reduced responses of inflammation, and did not show acetic acid-induced writhing responses, indicating that PGI2 participates in promotion of inflammation and pain sensation. EP3-deficent mice did not show febrile responses to both endogenous and exogenous pyrogen; PGE2 mediates pyrogen-induced fever generation via EP3. EP4-deficient mice died within three days after birth due to patency of ductus arteriosus. PGE2 plays an essential role in neonatal closure of ductus arteriosus via EP4. EP2-deficent female mice showed reduced fertility due to impaired ovulation and fertilization; PGE2 contributes to ovulation and fertilization through stimulation of cumulus expansion via EP2 and the resultant increase in cAMP level. Through these studies, we demonstrated importance of receptor subtype-specific activities. HDC-deficient mice showed reduced responses in lgE-dependent type l allergy, indicating that histamine is essential in this disease. Less