DNA Based Repair and MAP kinases

描述(申请人提供)：内源性和环境氧化可导致DNA损伤和其他细胞器损伤。例如，高氧是急性肺衰竭的主要治疗方法，但也会导致肺细胞毒性。由于高氧中毒和其他氧化反应的治疗在很大程度上是支持性的，自然防御机制很容易被击败，因此开发新的治疗策略是必要的。我们的初步数据表明，高氧诱导的细胞凋亡与丝裂原活化蛋白激酶(MARK、p38和ERK1/2)的激活有关。我们还发现DNA碱基切除修复(BER)蛋白可以逆转DNA氧化损伤。然而，目前还不清楚BER蛋白是否与Mark等信号蛋白相互作用。本应用的目的是确定BER在高氧DNA损伤中的作用和调节机制，特别是BER蛋白与Mark的相互作用。我们的中心假设是，BER蛋白可能调节或与Mark通路相互作用，从而逆转DNA损伤。高氧损伤的细胞必须要么由于细胞周期停滞而停止复制，要么与突变形式的DNA复制。因此，迫切需要DNA修复。如果不能修复DNA损伤，就会导致基因瓦解、细胞凋亡和最终的肺泡破裂。MARK可能有助于有效修复DNA损伤，因此是降低氧化毒性的关键途径。其基本原理是，更多关于BER与其他信号蛋白相互作用的知识将为更好地利用BER DNA修复蛋白防止氧化损伤提供基础。为了验证我们的假设，我们提出了以下具体目标：#1识别高氧诱导的DNA损伤和Mark活性的变化；#2评估BER蛋白在调节Mark活性中的作用。其意义在于，BER修复和信号蛋白的调节可能有助于对抗肺细胞的各种氧化损伤，包括化疗药物和重金属，如镉。

DESCRIPTION (provided by applicant): Endogenous and environmental oxidation can cause DMA damage along with other organelle injury. For example, hyperoxia is a main therapeutics for acute lung failure but also causes lung cell toxicity. Since treatment of hyperoxic toxicity and other oxidation is largely supportive and natural defense mechanisms are easily defeated, development of new therapeutic strategies is warranted. Our preliminary data indicates that hyperoxia induces apoptosis associated with activation of mitogen-activated protein kinases (MARK, p38 and ERK1/2). We have also found that DNA base excision repair (BER) proteins can reverse oxidative DMA damage. However, it is unclear whether BER proteins interact with signaling proteins such as MARK. The objective of this application is to determine roles of BER in hyperoxic DNA damage and the regulatory mechanism, particularly interactions of BER proteins with MARK. Our central hypothesis is that BER proteins may regulate or interact with the MARK pathway to reverse DNA damage. Hyperoxia injured cells must either cease replication due to cell cycle arrest or replicate with a mutant form of DNA. Thus, DNA repair is urgently needed. Failure to repair the DNA damage results in genetic disintegration, apoptotic cell death, and an ultimate alveolar breakdown. MARK may help efficiently repair DNA damage, thus a critical way to reduce oxidative toxicity. The rationale is that additional knowledge of BER interacting with other signaling proteins would provide a foundation to better use BER DNA repair proteins to prevent oxidative injury. To test our hypothesis, we propose the following Specific Aims: #1 To identify hyperoxia-induced DNA lesions and alterations of MARK activity; #2 To evaluate role of BER proteins in regulating MARK activity. The significance is that regulation of BER repair and signaling proteins may be potentially useful for counteracting various oxidative damage to lung cells, including chemotherapeutics and heavy metals, such as cadmium.