Pulsatile contractions promote apoptotic cell extrusion in epithelial tissues
Youmna Atieh1, Thomas Wyatt2, Ana Maria Zaske3
1Department of Genetics, The University of Texas MD Anderson Cancer Center, Houston, TX, USA.
Current Biology : CB
|January 5, 2021
Summary
Pulsatile actomyosin contractions, driven by myosin dynamics and caspase activation, dictate which damaged epithelial cells are extruded. These contractions
Area of Science:
- Epithelial biology
- Cellular dynamics
- Tissue homeostasis
Background:
- Epithelial tissues eliminate unfit cells via extrusion.
- The precise mechanisms initiating selective cell extrusion remain unclear.
Purpose of the Study:
- To investigate the cell and cytoskeletal dynamics preceding epithelial cell extrusion.
- To elucidate the molecular and physical cues governing selective cell removal.
Main Methods:
- Inducing damage in zebrafish epithelial cells.
- Utilizing time-lapse imaging to observe cellular and cytoskeletal behavior.
- Analyzing cell area, myosin localization, and caspase activation.
Main Results:
- Cell extrusion is preceded by pulsatile actomyosin contractions.
- Myosin relocalizes from junctions to the cell’s medial region, inducing pulses.
- Longer, higher-amplitude pulses correlate with progressive area loss and extrusion.
- Caspase activation, sphingosine-1-phosphate enrichment, and tissue tension regulate extrusion.
- Pulsatile contraction kinetics distinguish extruding from non-extruding cells.
Conclusions:
- The kinetics of pulsatile contractions are predictive of cell extrusion.
- Localized physical force changes coordinate defective cell removal for tissue homeostasis.
Related Concept Videos
01:16Cell Motility through Blebbing
2.2K
Blebs are a type of membrane protrusion formed by the internal hydrostatic pressure of the cytoplasm. Blebs are observed in several cell types, including fibroblasts, immune cells, and single-celled organisms like the amoeba. The primary function of blebs is cell locomotion and apoptosis, but they are also found during necrosis and cell division. The life cycle of a bleb comprises an initiation phase followed by the expansion and retraction phases.
Blebbing Through the Matrix
In multicellular...
Blebbing Through the Matrix
In multicellular...
2.2K
01:30Apoptosis
12.9K
Apoptosis is a combination of two Greek words, 'apo' and 'ptosis,' meaning separation and falling off, respectively. Hippocrates used this word to describe gangrene, which was caused due to bandaging of fractured bones. Apoptosis was distinguished from necrosis in 1970 when John Kerr reported observations of morphological changes occurring during apoptosis. During one experiment, he observed that the disruption of blood supply to the liver tissue resulted in a size...
12.9K
01:17Phagocytosis of Apoptotic Cells
4.3K
Cells undergoing apoptosis form apoptotic bodies that must be removed immediately to prevent inflammation, autoimmune diseases, and necrosis. Phagocytosis is carried out by professional phagocytes such as macrophages or immature dendritic cells. Non-professional phagocytes such as epithelial cells and fibroblasts also take part in this process; however, they are not as effective as professional phagocytes.
Normal cells contain receptors that prevent them from being recognized...
Normal cells contain receptors that prevent them from being recognized...
4.3K
01:17The Extrinsic Apoptotic Pathway
7.2K
The extrinsic apoptotic pathway is initiated when extracellular death-inducing signals, such as specific cytokines, activate the death receptors expressed on the cell surface. The immune cells involved in this pathway are natural killer cells (NK cells) and cytotoxic T-lymphocytes. NK cells are critical in innate immune response, while cytotoxic T-lymphocytes are associated with adaptive immune response. These cells recognize specific receptors expressed on the altered cells and activate...
7.2K
01:19Cell Migration
5.9K
Cell migration is a process by which the cells move from one location to another, playing an essential role in embryological development, repair and regeneration, immune response, and metastasis. Cells migrate in response to chemical or mechanical signals generated by specific organs or tissues. The overall mechanism includes three steps - polarization, protrusion, and release. Polarization involves the formation of a distinct cell front and rear, which determines the direction of movement.
5.9K
01:09Cell Migration
17.8K
Cell migration, the process by which cells move from one location to another, is essential for the proper development and viability of organisms throughout their life. When cells are not able to migrate properly to their ordained locations, various disorders may occur. For example, disruption in cell migration causes chronic inflammatory diseases such as arthritis.
17.8K