Decoding the gene regulatory network of mammalian cardiac maturation

/ABSTRACT The mammalian heart undergoes profound transcriptional and phenotypical remodeling during postnatal development, a process known as cardiac maturation. However, the molecular mechanisms driving this transition is not fully understood, posing a major challenge in cardiac regenerative medicine, where induced cardiomyocytes from pluripotent stem cell differentiation or non-myocyte reprogramming exhibit an overall immature phenotype that severely limits their application in cell therapy and in vitro disease modeling. In this K99/R00 application, I propose to integrate cutting-edge single cell multiomics with state-of-the-art computational methods to unravel the cell-type-specific gene regulatory networks governing cardiac maturation, and develop a novel dual-reporter system to model and enhance cardiac maturation in vitro and in vivo. During the K99 phase, I will characterize the epigenomic changes of the mouse heart during postnatal development at a single cell resolution using various single cell multiomic technologies (Aim 1), and construct cell-type-resolved gene regulatory networks underlying cardiac maturation using bioinformatic approaches coupled with deep learning (Aim 2). I will also establish cell culture and mouse models with CRISPR-mediated knock-in of dual-fluorescent reporters to track and assess cardiomyocyte maturation (Aim 3a). During the R00 phase, I will experimentally characterize key regulatory elements and novel transcriptional regulators using functional genomic approaches (Aim 3b). I will also leverage these findings to enhance the maturation of in vitro-derived cardiomyocytes for improved therapeutic potential (Aim 3c). The expected outcomes of my proposed research will deepen our understanding of postnatal cardiac development and uncover new therapeutic strategies to improve cardiac function after injury. My career goal is to lead an independent research group that develops and employs innovative technologies to study the regulatory mechanisms underlying cardiac development, regeneration, and disease. In my K99 phase, I will acquire crucial knowledge and skills in advanced single cell genomics and computational biology to complement my previous expertise in developmental biology and cardiac research. My career development will be supported by an exceptional mentoring and advisory committee from UCSD/Salk/HHMI, along with world-class resources, training opportunities, and institutional support at UC San Diego. These elements will provide a strong foundation for my successful transition to an independent tenure- track faculty position. Project Number: 1K99HL183669-01 | Fiscal Year: 2026 | NIH Institute/Center: National Heart Lung and Blood Institute (NHLBI) | Principal Investigator: Zhaoning Wang | Institution: COLUMBIA UNIVERSITY HEALTH SCIENCES, NEW YORK, NY | Award Amount: $124,688 | Activity Code: K99 | Study Section: Special Emphasis Panel[ZRG1 IVBH-A (90)] View on NIH RePORTER: https://reporter.nih.gov/project-details/1K99HL18366901