Search bioRxiv⌕ Search

bioRxiv · 10.1101/2023.12.20.570481

PRDM3/16 Regulate Chromatin Accessibility Required for NKX2-1 Mediated Alveolar Epithelial Differentiation and Function

Abstract

Differential chromatin accessibility accompanies and mediates transcriptional control of diverse cell fates and their differentiation during embryogenesis. While the critical role of NKX2-1 and its transcriptional targets in lung morphogenesis and pulmonary epithelial cell differentiation is increasingly known, mechanisms by which chromatin accessibility alters the epigenetic landscape and how NKX2-1 interacts with other co-activators required for alveolar epithelial cell differentiation and function are not well understood. Here, we demonstrate that the paired domain zinc finger transcriptional regulators PRDM3 and PRDM16 regulate chromatin accessibility to mediate cell differentiation decisions during lung morphogenesis. Combined deletion of Prdm3 and Prdm16 in early lung endoderm caused perinatal lethality due to respiratory failure from loss of AT2 cell function. Prdm3/16 deletion led to the accumulation of partially differentiated AT1 cells and loss of AT2 cells. Combination of single cell RNA-seq, bulk ATAC-seq, and CUT&RUN demonstrated that PRDM3 and PRDM16 enhanced chromatin accessibility at NKX2-1 transcriptional targets in peripheral epithelial cells, all three factors binding together at a multitude of cell-type specific cis-active DNA elements. Network analysis demonstrated that PRDM3/16 regulated genes critical for perinatal AT2 cell differentiation, surfactant homeostasis, and innate host defense. Lineage specific deletion of PRDM3/16 in AT2 cells led to lineage infidelity, with PRDM3/16 null cells acquiring partial AT1 fate. Together, these data demonstrate that NKX2-1-dependent regulation of alveolar epithelial cell differentiation is mediated by epigenomic modulation via PRDM3/16. Graphical Abstract O_FIG O_LINKSMALLFIG WIDTH=130 HEIGHT=200 SRC="FIGDIR/small/570481v1_ufig1.gif" ALT="Figure 1"> View larger version (27K): org.highwire.dtl.DTLVardef@500f6org.highwire.dtl.DTLVardef@821daaorg.highwire.dtl.DTLVardef@69ba87org.highwire.dtl.DTLVardef@154f754_HPS_FORMAT_FIGEXP M_FIG C_FIG Model of the role of PRMD3/16 in alveolar developmentPRMD3/16 participate in cell fate specification in the lung by modulating chromatin accessibility (top row) and by partnering with NKX2-1 and partner transcription factors to drive gene expression (second row) via a gene regulatory network required for terminal cell differentiation and surfactant expression in AT2 cells (third row). Loss of PRDM3/16 activity in lung endoderm leads to reduced AT2 quorum, failure of AT2 surfactant function, and transition to an immature AT1 phenotype (bottom panel).

Source connections

Explore related subjects

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

He, H., Bell, S. M., Davis, A. K., Zhao, S., Sridharan, A., Na, C.-L., Guo, M., Xu, Y., Snowball, J., Swarr, D. T., Zacharias, W. J., Whitsett, J. A.. 2023-12-20. PRDM3/16 Regulate Chromatin Accessibility Required for NKX2-1 Mediated Alveolar Epithelial Differentiation and Function. https://doi.org/10.1101/2023.12.20.570481

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related preprints

Hyaluronic acid dynamics are regulated by neural crest cells and NEDD4 in the developing cardiac outflow tract valves

The extracellular matrix (ECM) is essential for cardiac valve development, with hyaluronic acid (HA) playing a critical role in cardiac cushion formation. While HA is required for atrioventricular valve development, its role in semilunar valve formation remains poorly understood. The ubiquitin ligase NEDD4 is essential for cardiac outflow tract development, particularly within cardiac neural crest cells, however its role in semilunar valve development has been unexplored. Here, we demonstrate that neural crest-specific deletion of NEDD4 in mice disrupts outflow tract valve development, resulting in abnormal leaflet number and morphology. Analysis of valve ECM revealed a specific reduction in HA within the neural crest-derived valve mesenchyme, while other ECM components such as fibronectin and versican remained unaffected. In contrast, deletion of NEDD4 in endocardium-derived valve mesenchyme did not alter HA abundance. Using NEDD4-deficient neural crest cells, we further demonstrate a cell-autonomous requirement for NEDD4 in regulating HA abundance, with in vitro evidence supporting impaired HA synthesis rather than increased turnover of HA in the ECM. Our findings identify a previously unrecognised role for NEDD4 in regulating HA synthesis in cardiac neural crest cells, revealing a cell-type-specific mechanism governing semilunar valve development and highlighting distinct cellular requirements for ECM regulation across cardiac valve populations.

developmental biology↗

Cxcr2 is required for ductal outgrowth and shapes the stromal microenvironment in postnatal mammary gland development

Mammary gland development requires coordinated signaling between epithelial and stromal compartments. While CXC chemokine receptor 2 (CXCR2) is known to regulate inflammatory and tissue remodeling processes in disease, including breast cancer, its role in mammary gland morphogenesis is not well understood. Here, we examined postnatal mammary gland development in germline Cxcr2 knockout mice. Loss of Cxcr2 resulted in delayed ductal outgrowth, reduced epithelial area, and altered stromal architecture, including decreased adipocyte size and increased collagen deposition, despite preserved branching organization. These defects occurred in the context of severe systemic immune dysregulation, marked by expansion of granulocytic populations and loss of adaptive immune cells. Together, our findings indicate that CXCR2 indirectly regulates mammary gland development through coordination between the epithelium and stroma, rather than acting through epithelial cell-intrinsic mechanisms. Because the same myeloid expansion, immune suppression, and collagen-rich stromal remodeling that CXCR2 controls during normal development are hallmarks of the pro-tumorigenic breast microenvironment, these findings establish CXCR2 as a regulator of the immune and stromal landscape of the mammary gland and provide a developmental framework for understanding its contributions to the breast tumor microenvironment.

developmental biology↗

Endogenous Mechanical Reporters Encode the Global Mechanical Landscape of Morphogenesis

Developmental systems usually comprise multiple genetically programmed morphogenetic events within a mechanically continuous environment, yet how individual processes interact and contribute to the overall mechanical landscape remains unknown. Here, we introduce the concept of mechanical reporter: endogenous tissues function as in situ probes of the embedded mechanical landscape. We exemplified cephalic furrow (CF) migration as a mechanical reporter in gastrulating Drosophila. Using optogenetics and genetics, we revealed that CF displacement reflects the combined effect of both force and tissue mechanical properties. By incorporating condition-specific mechanical landscape into a continuum minimal-response model, we developed a framework to quantitatively predict the reporter dynamics. Using different genetic mutants, we successfully decoded changes in the mechanical landscape from CF dynamics in gastrulating Drosophila. Overall, we established a predictive framework that uses CF dynamics to infer changes in the global mechanical landscape. Beyond this, the concept of mechanical reporter provides a general strategy for systematically understanding and decoding complex mechanical environments in living systems.

developmental biology↗