Department of Cell and Developmental Biology, Vanderbilt University School of Medicine, Nashville, TN, USA.
Vanderbilt Cell Imaging Shared Resource, Vanderbilt University , Nashville, TN, USA.
J Cell Biol. 2024 Dec 2;223(12). doi: 10.1083/jcb.202404070. Epub 2024 Oct 1.
Tuft cells are a rare epithelial cell type that play important roles in sensing and responding to luminal antigens. A defining morphological feature of this lineage is the actin-rich apical "tuft," which contains large fingerlike protrusions. However, details of the cytoskeletal ultrastructure underpinning the tuft, the molecules involved in building this structure, or how it supports tuft cell biology remain unclear. In the context of the small intestine, we found that tuft cell protrusions are supported by long-core bundles that consist of F-actin crosslinked in a parallel and polarized configuration; they also contain a tuft cell-specific complement of actin-binding proteins that exhibit regionalized localization along the bundle axis. Remarkably, in the sub-apical cytoplasm, the array of core actin bundles interdigitates and co-aligns with a highly ordered network of microtubules. The resulting cytoskeletal superstructure is well positioned to support subcellular transport and, in turn, the dynamic sensing functions of the tuft cell that are critical for intestinal homeostasis.
类指突细胞是一种罕见的上皮细胞类型，在感知和响应腔抗原中发挥重要作用。该谱系的一个定义性形态特征是富含肌动蛋白的顶端“类指突”，其中包含大的指状突起。然而，支持类指突的细胞骨架超微结构的细节、参与构建该结构的分子，或它如何支持类指突细胞生物学仍然不清楚。在小肠的背景下，我们发现类指突细胞的突起由长核心束支撑，这些核心束由平行且极化排列的 F-actin 交联而成；它们还包含一组特定的肌动蛋白结合蛋白，这些蛋白在沿着束轴的区域化定位。值得注意的是，在亚顶细胞质中，核心肌动蛋白束的排列与高度有序的微管网络交织并对齐。由此产生的细胞骨架超结构非常适合支持细胞内运输，进而支持类指突细胞的动态感应功能，这对于肠道内稳态至关重要。
