Cardiovascular diseases such as cardiac bypass surgery or hypertension, effects kidney function and causes acute of chronic kidney diseases (CKD). A common denominator of chronic kidney disease is fibrosis and determines disease progression. There is an immediate need to identify therapeutic targets, which can stop or delay progression of fibrosis. STAT3, a key transcription factor activated in various disease. We found that STAT3 deletion from pericytes protects mice from kidney fibrosis. In the proposed project, we will study the role of STAT3 transcriptional repositioning in kidney cell specific STAT3 null mice (proximal tubular or pericytes knockout) during AKI to fibrosis progression. Additionally, we are proposing the use of already available Ser727Ala mice and developing Tyr705Phe mice to study these phosphorylation events in promoter binding during AKI to CKD progression. Using mouse models and in vitro cell based systems we propose to investigate transcriptional repositioning (binding of transcription factor on different promoters depending on upstream signaling or the components of the transcriptional assembly) of STAT3 during this transition. Further, we observed that STAT3 phosphorylation is limited to the proximal tubular epithelial cells during AKI, but in the case of fibrosis, STAT3 is expressed in other cell types including glomerular, interstitial cells and fibroblasts in murine and human kidneys. We have identified a promoter repositioning of STAT3 and differential expression of its transcriptional targets (RNASeq) during fibrosis development. These proposed experiments will advance our understanding of CKD pathogenesis, produce innovative cell lines and methodologies for future research, and expand Dr. Ajay's technical scope to include new skills of CRISPR mediated genome editing, and in vivo cell isolation, single cell analysis and generation of mouse models. Dr. Ajay will devote 100% of his time to research under this award and HMS will promote him to an assistant professor. Dr. Bonventre is providing mentorship to Dr. Ajay, providing him with office and laboratory space and research personnel. Dr. Ajay will be co-mentored by expert in the STAT3 biology and immunology at the HMS, namely Dr. Frank and Dr. Gopal. He will meet with his mentors on a two-monthly basis. He will be expected to produce first authored manuscripts during the award period with the goal of becoming competitive for independent research awards such as R01.
|Program type||Career Development Award|
|Effective start/end date||04/01/2019 → 03/31/2022|