Tracheal separation is driven by NKX2-1-mediated repression of Efnb2 and regulation of endodermal cell sorting

Ace E Lewis; Akela Kuwahara; Jacqueline Franzosi; Jeffrey O Bush

doi:10.1016/j.celrep.2022.110510

Tracheal separation is driven by NKX2-1-mediated repression of Efnb2 and regulation of endodermal cell sorting

Cell Rep. 2022 Mar 15;38(11):110510. doi: 10.1016/j.celrep.2022.110510.

Authors

Ace E Lewis¹, Akela Kuwahara², Jacqueline Franzosi¹, Jeffrey O Bush³

Affiliations

¹ Department of Cell and Tissue Biology, University of California, San Francisco, San Francisco, CA 94143, USA; Program in Craniofacial Biology, University of California, San Francisco, 513 Parnassus Avenue, Box 0512, San Francisco, CA 94143, USA; Institute for Human Genetics, University of California, San Francisco, San Francisco, CA 94143, USA; Eli and Edythe Broad Center of Regeneration Medicine and Stem Cell Research, University of California, San Francisco, San Francisco, CA 94143, USA.
² Department of Cell and Tissue Biology, University of California, San Francisco, San Francisco, CA 94143, USA; Program in Craniofacial Biology, University of California, San Francisco, 513 Parnassus Avenue, Box 0512, San Francisco, CA 94143, USA; Institute for Human Genetics, University of California, San Francisco, San Francisco, CA 94143, USA; Eli and Edythe Broad Center of Regeneration Medicine and Stem Cell Research, University of California, San Francisco, San Francisco, CA 94143, USA; Developmental and Stem Cell Biology Graduate Program, University of California, San Francisco, San Francisco, CA 94143, USA.
³ Department of Cell and Tissue Biology, University of California, San Francisco, San Francisco, CA 94143, USA; Program in Craniofacial Biology, University of California, San Francisco, 513 Parnassus Avenue, Box 0512, San Francisco, CA 94143, USA; Institute for Human Genetics, University of California, San Francisco, San Francisco, CA 94143, USA; Eli and Edythe Broad Center of Regeneration Medicine and Stem Cell Research, University of California, San Francisco, San Francisco, CA 94143, USA. Electronic address: jeffrey.bush@ucsf.edu.

Abstract

The mechanisms coupling fate specification of distinct tissues to their physical separation remain to be understood. The trachea and esophagus differentiate from a single tube of definitive endoderm, requiring the transcription factors SOX2 and NKX2-1, but how the dorsoventral site of tissue separation is defined to allocate tracheal and esophageal cell types is unknown. Here, we show that the EPH/EPHRIN signaling gene Efnb2 regulates tracheoesophageal separation by controlling the dorsoventral allocation of tracheal-fated cells. Ventral loss of NKX2-1 results in disruption of separation and expansion of Efnb2 expression in the trachea independent of SOX2. Through chromatin immunoprecipitation and reporter assays, we find that NKX2-1 likely represses Efnb2 directly. Lineage tracing shows that loss of NKX2-1 results in misallocation of ventral foregut cells into the esophagus, while mosaicism for Nkx2-1 generates ectopic NKX2-1/EPHRIN-B2 boundaries that organize ectopic tracheal separation. Together, these data demonstrate that NKX2-1 coordinates tracheal specification with tissue separation through the regulation of EPHRIN-B2 and tracheoesophageal cell sorting.

Keywords: Eph/ephrin; Nkx2-1; Sox2; cell sorting; endoderm; ephrin-B2; esophagus; foregut; trachea; tracheoesophageal fistula.

Publication types

Research Support, N.I.H., Extramural
Research Support, Non-U.S. Gov't

MeSH terms

Digestive System / metabolism
Endoderm* / metabolism
Ephrin-B2 / metabolism
Esophagus / metabolism
Trachea* / metabolism

Substances

Ephrin-B2

Abstract

Publication types

MeSH terms

Substances

Grants and funding