. I aspire to become an independent investigator with a lab at a vibrant academic medical center and a leader in the study of mitochondrial dysfunction in lung disease, namely chronic obstructive pulmonary disease (COPD). To continue my progress towards this goal, I am proposing a multifaceted approach to address the specific hypothesis surrounding the deregulation of mitochondrial iron metabolism in the lung and the development of COPD, a timely and important topic. I posses the background, training and expertise in the key research areas for this application. I have carefully chosen an advisory committee composed of my mentor Prof. Augustine Choi, a world-renowned leader in pulmonary research and other accomplished investigators at Weill Cornell Medical College (WCMC) who will mentor and guide me throughout the time frame of this award. This award will provide critical support and time to continue my research under the mentorship of Prof. Choi at WCMC. Augustine's laboratory contains well-established facilities and expertise for carrying out pulmonary research and is an ideal environment for translating bench discoveries to disease-specific aspects of this project. It will also provide protected time to train in the ey research areas defined in this application specifically learning how to; 1) study mitochondrial iron metabolism 2) image mitochondria in the lung and 3) develop mitochondrial-based therapeutics for use in vivo. In the R00 phase of the award I will apply this training to better understand the pathogenesis of COPD and evaluate the efficacy of these methods for COPD therapeutics. The energetic dynamic environment of WCMC will provide me access to world-class research facilities, and allow me to expand my knowledge, skills and professional network. My collaborations within WCMC and outside including Columbia University Medical Center in New York, Harvard Medical School and Northeastern University in Boston will not only allow me to interact with a range of investigators with diverse skill sets, but will also allow me to presen and share my data with others to gain important peer-reviewed feedback. The projects and training proposed in this application along with the expertise and experience afforded by my advisory committee and collaborators will provide me with the trans-disciplinary skills and knowledge I need to develop as an independent investigator. In this proposal I seek to characterize further the functional role of the COPD susceptibility gene transcript IRP2 in the pathogenesis of cigarette smoke (CS)-induced COPD. I also wish to use IRP2 as a tool to investigate the role of mitochondrial metabolism in lung function and the susceptibility of the lung to cigarette smoke. I show that mice lacking IRP2 are protected from CS-induced bronchitis and emphysema and have altered responses to CS exposure. IRP2 recognizes and binds to iron response elements located in mRNA resulting in translational repression or stabilization. To identify novel IRP2 target transcripts in the lung I performed 1) microarray analysis of IRP2-/- mouse lungs and 2) RIP-Seq, specifically, immunoprecipitation of IRP2 from human bronchial epithelial cells followed by next generation sequencing of IRP2-bound RNA. Preliminary data from these experiments showed that IRP2 regulates transcripts important for mitochondrial iron metabolism and function in the lung. I compared these data with RNA-Seq data from the Lung Genomics Research Consortium, which included controls and patients with COPD. The same pathways identified by the IRP2 RIP-Seq and microarray were altered in COPD patients, further strengthening the association between IRP2, these pathways and the development of COPD. Based on this preliminary data, I hypothesize that IRP2 modulates pathways important for the response of the lung to cigarette smoke by regulating mitochondrial function. This hypothesis will be tested using the following aims: 1. Characterize the function of IRP2 in the response of mitochondria to CS exposure. 2. Determine the function of IRP2-regulated mitochondrial pathways in experimental COPD. 3. Determine mitochondrial-based approaches for COPD therapy. With a panel of novel reagents and assays including IRP2-/- mice, in vivo models for COPD, innovative mitochondrial-targeted therapeutics and novel real-time approaches to imaging the lung in vivo, this project proposes a multifaceted, interdisciplinary approach to characterize the mechanisms by which IRP2 regulates CS responses in the lung and how this plays a critical role in the pathogenesis of COPD. COPD remains a complex debilitating disease that encompasses a variety of pathologic conditions including emphysema and chronic bronchitis and affects approximately 15 million people in the USA. Few advances have been made to alleviate the bronchitis or emphysema associated with COPD with suboptimal therapeutic options mildly improving the symptoms of COPD rather than substantially modifying its course. Discoveries, techniques and observations made in these studies will contribute greatly to investigators of basic respiratory medicine in the COPD field and also to investigators in other fields related to mitochondrial iron-associated disorders. Most importantly these studies may also aid in the design of better therapeutic agents to target COPD and help reduce the burden of this lung disease on patients and their families.
We have previously demonstrated that patients with a mutation in the gene iron regulatory protein 2 (IRP2) have augmented levels of IRP2 and are more susceptible to cigarette smoke (CS)-induced Chronic Obstructive Pulmonary Disease (COPD). Based on preliminary data that 1) mice lacking IRP2 are protected from CS- induced COPD and 2) IRP2 targets proteins involved in cellular energy regulation and iron metabolism in the mitochondria of the lung, this proposal seeks to determine how IRP2 regulates mitochondrial responses to CS and how these responses may be exploited for therapy. I require further mentoring, training and guidance to characterize these responses using a series of innovative approaches and I plan to cultivate these skills and apply them to develop my own research niche evaluating novel mitochondrial-based therapeutic strategies for COPD.
|Cloonan, Suzanne M (2017) Circulating Mitochondrial DNA as a Mechanism-based, Prognostic Biomarker for Idiopathic Pulmonary Fibrosis. Am J Respir Crit Care Med 196:1502-1504|
|Cloonan, Suzanne M; Mumby, Sharon; Adcock, Ian M et al. (2017) The ""Iron""-y of Iron Overload and Iron Deficiency in Chronic Obstructive Pulmonary Disease. Am J Respir Crit Care Med 196:1103-1112|
|Mizumura, Kenji; Cloonan, Suzanne; Choi, Mary E et al. (2016) Autophagy: Friend or Foe in Lung Disease? Ann Am Thorac Soc 13 Suppl 1:S40-7|
|Cloonan, Suzanne M; Choi, Augustine M K (2016) Mitochondria in lung disease. J Clin Invest 126:809-20|
|Cloonan, Suzanne M; Glass, Kimberly; Laucho-Contreras, Maria E et al. (2016) Mitochondrial iron chelation ameliorates cigarette smoke-induced bronchitis and emphysema in mice. Nat Med 22:163-74|