Aminopeptidase N Driven Signaling in the Development of Pulmonary Hypertension

/ABSTRACT CANDIDATE: Dr. James's career objective is to establish an independent research group investigating mitochondrial dysfunction (MD) and Aminopeptidase N (APN) driven signaling in pulmonary hypertension (PH). The overall research and career development plan is carefully crafted to impart the necessary skills for Dr. James to establish a novel and independent line of research. The plan includes the following objectives: 1) gain additional training in research methodology and professional development; 2) developing strong publication records; 3) presenting his work at scientific meetings to make an impact on the field 4) obtaining preliminary data for his first independent grant. ENVIRONMENT: The primary mentor Dr. Rafikov is an expert in mitochondrial dysfunction and PH. He will provide guidance and technical expertise for aspects in all aims. Co-Mentor Dr. Vinicio de Jesus Perez is an expert in pericyte biology and PH and will train Dr. James in pericyte isolation, co- culture, and data analysis. Co-mentor Dr. Ralph Fregosi is an expert electrophysiologist and will extensively prepare Dr. James in his career development in addition to training with patch clamp techniques. All the mentors with the rest of the advisory committee will ensure the success of Dr. James's proposal. All the proposed work will be carried out in Dr. Rafikov's laboratory with training gained from labs of Dr. de Jesus Perez and Dr. Zhiyu Dai for single cell transcriptomics. Dr. Rafikov has all the necessary funding from NIH and other sources to support Dr. James during the K99 training phase. The Department of Medicine at the University of Arizona has excellent facilities and supportive faculty members and provides a nurturing environment for the training phase. RESEARCH: The overarching hypothesis is that MD triggers the overexpression of the protein, APN in pericytes. APN has been shown to cause migration, invasion, and proliferation of cells. Preliminary data suggests that MD in rats triggers an increase in pericyte APN, causing them to dissociate from endothelial cells (EC's) in capillaries, transform into smooth muscle-like cells (PASMC) and proliferate. This ultimately leads to vascular remodeling and PH. Three specific aims will address this hypothesis. Aim 1: To Investigate the role of APN in pericyte-EC communication and pericyte transformation to PASMC. Aim 2: To Investigate the role of MD on APN expression and signaling. Aim 3: To Verify the impact of blocking APN and reversing MD on vascular remodeling in PH. The study will utilize several techniques including single cell transcriptomics, 3D imaging and co-culture to address these questions. The results of this study will lead to a better understanding of how MD drives APN expression and signaling. This could define novel targets in the treatment of PH for favorable clinical outcomes. The proposed training will enable Dr. James to acquire new experimental skills and execute his research plan successfully. This will allow Dr. James to become self-sufficient, able to secure extramural funding and a tenure- track position at a top-tier research institution. Project Number: 4R00HL171869-03 | Fiscal Year: 2025 | NIH Institute/Center: National Heart Lung and Blood Institute (NHLBI) | Principal Investigator: Joel James | Institution: INDIANA UNIVERSITY INDIANAPOLIS, INDIANAPOLIS, IN | Award Amount: $249,000 | Activity Code: R00 | Study Section: NSS View on NIH RePORTER: https://reporter.nih.gov/project-details/4R00HL17186903