Extract
The lung is a notoriously quiescent organ with a very limited proportion of detectable proliferative cells in normal conditions. However, in response to injury, facultative progenitor cells have the capabilities to proliferate and differentiate. Over the past decades, several lung progenitor populations have been identified following their location (i.e. proximal versus distal airways and alveolar region) [1]. In both humans and mice, several epithelial lineages are found in the trachea and upper airways, such as secretory (club), goblet, ciliated and neuroendocrine cells, along with the basal cells that line the epithelia. These basal cells have the capacity to self-renew and, when necessary, differentiate into other epithelial cells, such as ciliated, secretory or goblet cells [2–4]. In mice, basal cells are restricted to the trachea and main large bronchi, so additional epithelial populations with facultative progenitor abilities exist. For instance, lineage-tracing experiments have demonstrated that, after injury, secretory Scgb1a1+ cells, but not ciliated cells, may give rise to goblet cells [5]. Also, after proximal airways damage, some rare neuroendocrine cells, embedded in clusters called neuroendocrine bodies, proliferate and differentiate to repair the surrounding epithelium [6]. Variant club-secretory cells, located near neuroendocrine bodies, expressing Upk3a and resistant to naphthalene injury, are also able to differentiate into secretory and ciliated cells [7, 8].
Abstract
A novel AT2 subset with Sftpclow and PD-L1high expression is capable of producing mature AT2 cells upon injury https://bit.ly/2TDTQeS
Footnotes
Conflict of interest: C. Fouillade has nothing to disclose.
Conflict of interest: A. Londoño-Vallejo has nothing to disclose.
Support statement: This work was supported by Agence Nationale de la Recherche (grant: ANR-14-CE36-0008-02) and Institut National Du Cancer (grant: INCa-DGOS-4654). Funding information for this article has been deposited with the Crossref Funder Registry.
- Received May 19, 2021.
- Accepted June 30, 2021.
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