Desmosomal Junctions Govern Tissue Integrity and Actomyosin Contractility in Apoptotic Cell Extrusion
Thomas M, Ladoux B, Toyama Y (2020)
Publication Type: Journal article
Publication year: 2020
Journal
Book Volume: 30
Pages Range: 682-690.e5
Journal Issue: 4
DOI: 10.1016/j.cub.2020.01.002
Abstract
During apoptosis, or programmed cell death, a dead cell could be expelled from the tissue by coordinated processes between the dying cell and its neighbors. Apoptotic cell extrusion is driven by actomyosin cable formation and its contraction and lamellipodial crawling of the neighboring cells [1–4]. Throughout cell extrusion, the mechanical coupling of epithelia needs to be maintained in order to preserve tissue homeostasis [1]. Although much is known about the regulation of adherens junctions (AJs) in apoptotic cell extrusion [4–7], the role and dynamics of desmosomal junctions (DJs) during this process remain poorly understood. Here, we show that DJs stay intact throughout and are crucial for cell extrusion. Pre-existing DJs between the apoptotic cell and neighboring cells remain intact, even during the formation of de novo DJs between non-dying cells, suggesting the neighboring cells possess two DJs in the middle of apoptotic cell extrusion. We further found that an actomyosin cable formed in the vicinity of DJs upon apoptosis and subsequently deviated from DJs during its constriction. Interestingly, the departure of the actomyosin cable from DJs coincided with the timing when DJs lost their straightness, suggesting a release of junctional tension at DJs and a mechanical coupling between DJs and actomyosin contractility. The depletion of desmoplakin resulted in defective contractility and an inability to form de novo DJs, leading to a failure of apoptotic cell extrusion. Our study provides a framework to explain how desmosomes play pivotal roles in maintaining epithelial sheet integrity during apoptotic cell extrusion. Thomas et al. show pivotal role of desmosomal junction in governing actomyosin contractility and maintenance of epithelial sheet integrity during apoptotic cell extrusion. We speculate that desmoplakin-depleted tissues could lead to pathological conditions through defective actomyosin contractility and/or apoptotic cell clearance.
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Singapore (SG)
France (FR)How to cite
APA:
Thomas, M., Ladoux, B., & Toyama, Y. (2020). Desmosomal Junctions Govern Tissue Integrity and Actomyosin Contractility in Apoptotic Cell Extrusion. Current Biology, 30(4), 682-690.e5. https://doi.org/10.1016/j.cub.2020.01.002
MLA:
Thomas, Minnah, Benoit Ladoux, and Yusuke Toyama. "Desmosomal Junctions Govern Tissue Integrity and Actomyosin Contractility in Apoptotic Cell Extrusion." Current Biology 30.4 (2020): 682-690.e5.
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