1. Constructing polymorphonuclear cells: chromatin folding shapes nuclear morphology.
- Author
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Murre, Cornelis, Patta, Indumathi, Mishra, Shreya, and Hu, Ming
- Abstract
In mammalian polymorphonuclear cells, polymorphonuclear structures are assembled by loop extrusion. Mega-loop anchors and interchromosomal hubs are stabilized by nuclear condensates. Diminished loop extrusion might alter nuclear deformability. Loop extrusion programs may instruct cellular architecture. It might be feasible to engineer artificial nuclear shapes and altered nuclear deformability to manipulate immune effector cell migration. Since the cardinal discovery by Metchnikoff that neutrophils assemble into polymorphonuclear structures, insights into the mechanisms that underpin the formation of such structures have remained rudimentary. Recent studies have demonstrated that in early mammalian hematopoiesis, mononuclear versus polymorphonuclear cell fate decisions are orchestrated by intricate competitive physical forces that involve loop extrusion and phase separation programs. Changing loop extrusion programs might enable the engineering of new nuclear shapes and artificial cytoplasmic architectures in effector immune cells and beyond. Immune cell fate decisions are regulated, at least in part, by nuclear architecture. Here, we outline how nuclear architecture instructs mammalian polymorphonuclear cell differentiation. We discuss how in neutrophils loop extrusion mechanisms regulate the expression of genes involved in phagocytosis and shape nuclear morphology. We propose that diminished loop extrusion programs also orchestrate eosinophil and basophil differentiation. We portray a new model in which competitive physical forces, loop extrusion, and phase separation, instruct mononuclear versus polymorphonuclear cell fate decisions. We posit that loop extrusion programs instruct the spatial organization of cytoplasmic organelles, including neutrophil granules, mitochondria, and endoplasmic reticulum. Finally, we suggest that changing loop extrusion programs might allow the engineering of new nuclear shapes and artificial cytoplasmic architectures. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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