The Study of Sphingolipid Metabolism in Airway Remodeling

我们研究了强脂质炎症介质1-磷酸鞘氨醇（S1 P）在支气管哮喘发病机制中的作用。为了理解鞘脂的作用，我们设计了如下的体外和体内研究。1）支气管上皮细胞和肺成纤维细胞鞘脂功能的分析最近的研究表明，抗原激发后哮喘患者支气管肺泡灌洗液中S1 P增加。为了阐明S1 P增加的功能，我们研究了支气管上皮细胞中产生S1 P的鞘氨醇激酶的活性。TNFα刺激增加了两种鞘氨醇激酶亚型的活性，而S1 P本身吸引MMP和IL-8分泌（提交数据中）。此外，我们发现S1 P通过Rho依赖性途径以及TGFβ诱导肺成纤维细胞中的肌成纤维细胞形成（在提交的数据中）。结论鞘脂是气道重塑的关键因素之一，因此鞘氨醇激酶基因导入培养细胞是必要的。2）卵清蛋白（OVA）致敏小鼠鞘氨醇激酶表达分析C57/BL 6小鼠在致敏后连续3 ~ 21天吸入OVA。我们比较了急性期和慢性期的两种策略。Western印迹分析和真实的时间PCR显示，鞘氨醇激酶表达在吸入3天时暂时降低，并在21天时恢复（未发表的数据）。免疫组织化学研究已经进行，我们正在准备在体内鞘氨醇激酶基因导入研究，以进一步分析。

We have examined the function of sphingosine 1-phospate (S1P), one of strong lipid inflammatory mediators, in the mechanism of bronchial asthma. To understand the role of sphingplipids, we designed in vitro and in vivo studies as below. However, our plans have not completed yet and some projects have been still undergoing.1)The analysis of sphingolipid function in bronchial epithelial cells and lung fibroblastsRecent article revealed that S1P is increased in bronchoalveolar lavage fluid of asthma patients after antigen challenge. To clarify the function of increased S1P, we studied the activity of sphingosine kinases that produce S1P in bronchial epithelial cells. TNFα stimulation increased the activities of both two isoforms of sphingosine kinase, whereas S1P itself attracted MMP and IL-8 secretion (in submission data). Moreover, we showed that S1P induced myofibroblast formation in lung fibroblasts via a Rho-dependent pathway, as well as TGFβ (in submission data). We concluded that sphingolipids is one of key factors for airway remodeling, then gene introduction of sphingosine kinases into cultured cells is preparing.2)The analysis of sphingosine kinase expression in ovalbumin(OVA)-sensitized miceC57/BL6 mice received OVA inhalation for 3 to 21 consecutive days after sensitization. We compared two strategies of acute and chronic phases. Western blot analysis and real time PCR revealed that sphingosine kinase expression was decreased temporary at 3-day inhalation and recovered at 21-day (unpublished data). Immunohistochemical study has been undergoing and we are preparing in vivo gene introduction study of sphingosine kinases for further analysis.