Functions of PPAR in the lung

本研究的目的是了解过氧化物酶体增殖物激活受体（PPARs）在肺中的作用。我们已经证明PPARb和PPARg在肺泡II型和I型细胞中高度表达。我们正在使用小鼠II型细胞、特异性PPAR配体以及PPARa和PPARb敲除小鼠的体外细胞系统来研究这些核受体在正常肺和肺炎症疾病（包括纤维化和哮喘）期间的功能。用PPAR特异性配体处理细胞，分离RNA进行微阵列分析，以鉴定PPAR调控的基因。这些研究已经确定了几个由ppar以时间和剂量依赖的方式调节的基因。此外，我们正在研究细胞因子和PPAR信号传导之间的相互作用。我们已经证明用白细胞介素1b治疗人肺成纤维细胞可下调PPARg的表达。这种下调对IL-1b和TNF-a是特异性的，而对其他白介素包括IL-3、IL-13、Il-8和il - 4没有观察到。地塞米松可阻止PPARg表达的降低。这些结果表明不同受体和细胞因子通路之间存在串扰。

The objective of this study is to understand the roles that peroxisome proliferator-activated receptors (PPARs) have in the lung. We have shown that PPARb and PPARg are highly expressed in lung alveolar type II and Type I cells. We are using an in vitro cell system of murine Type II cells, specific PPAR ligands, and PPARa and PPARb knockout mice to study the function of these nuclear receptors in normal lung and during lung inflammatory disease including fibrosis and asthma. Cells were treated with PPAR-specific ligands, RNA isolated and used in microarray analysis in order to identify genes genes regulated by PPAR. These studies have identified several genes that regulated by PPARs in a time and dose-dependent manner. In addition, we are examining the interaction between cytokine and PPAR signaling. We have shown that treatment of human lung fibroblasts with interleukin 1b downregulates PPARg expression. This down-regulation is specific for IL-1b and TNF-a and is not observed with other interleukins including IL-3, IL-13, Il-8, and IL4. The decrease in PPARg expression is prevented by dexamethasone. These results suggest crosstalk between different receptor and cytokine pathways.