Parent-specific epigenetic marks (imprints) leading to parent-specific gene expression are crucial for normal growth and development, yet their mechanisms of establishment and maintenance are not fully understood. In humans, approximately 200 imprinted genes have been discovered, and improper imprinting can manifest in growth restriction, obesity, intellectual disabilities, behavioral abnormalities, and an increased risk of certain cancers. While the use of pluripotent stem cells, especially those in the naïve state, have advanced aspects of modeling early development, a persistent issue hampering bona fide naïve hPSCs is the erosion of imprints. Our guests on today's episode will discuss genomic imprinting, its function, impact, and a new reporter system of imprinted gene expression in hPSCs that enables real-time visualization of loss-of-imprinting at single-cell resolution. This assay provides an important tool to help discover how to improve the imprint fidelity of naïve hPSCs and hence their application for studies of human development and regeneration.

The mature lung in both humans and mice is highly vascularized, with approximately 30% of all cells being endothelial cells (ECs). The blood vessels have a physiological role in gas exchange within the tissue, but the vascular cells have additional role(s) beyond supplying oxygen and nutrients to the tissue.  For example, the adult lung endothelium responds to injury by activating pathways for alveolar re epithelialization and during embryonic development, disrupting vascularization ex vivo affects the stereotypical pattern of airway branching, consistent with a perfusion-independent crosstalk between the endothelium and epithelium. Today’s guests explore the molecular contribution of ECs and pericytes to the differentiation of distal airway progenitor cells into mature alveolar epithelial cells and will discuss the broader role of the vascular system in the maturation and regeneration or the lung.