美国哈佛大学David T. Scadden、Youmna S. Kfoury等研究人员合作发现造血细胞微环境中压力调节的囊泡转移。2021年9月21日，《细胞—干细胞》杂志在线发表了这项成果。

研究人员证明了骨髓（BM）基质中的成骨细胞产生了细胞外囊泡（EV），并被体内的造血祖细胞所吸收。遗传毒性或感染性压力迅速增加了基质衍生的EV向粒细胞-单核细胞祖细胞的转移。细胞外囊泡含有经过处理的tRNA（tiRNA），已知可调节蛋白质翻译。5′-ti-Pro-CGG-1在成骨细胞衍生的细胞外囊泡中优先丰富，当转移到粒细胞-单核细胞祖细胞时，增加了蛋白质翻译、细胞增殖和骨髓类分化。

上调EV的转移改善了造血功能从基因毒性损伤中的恢复和真菌败血症的生存。因此，EV介导的tiRNA转移在BM微环境中提供了一个压力调节信号轴，并且不同于传统细胞因子驱动的压力响应。

据介绍，EV在细胞之间转移复杂的生物材料。然而，这一过程在体内的作用却没有得到很好的定义。

附：英文原文

Title: tiRNA signaling via stress-regulated vesicle transfer in the hematopoietic niche

Author: Youmna S. Kfoury, Fei Ji, Michael Mazzola, David B. Sykes, Allison K. Scherer, Anthony Anselmo, Yasutoshi Akiyama, Francois Mercier, Nicolas Severe, Konstantinos D. Kokkaliaris, Ting Zhao, Thomas Brouse, Borja Saez, Jefferson Seidl, Ani Papazian, Pavel Ivanov, Michael K. Mansour, Ruslan I. Sadreyev, David T. Scadden

Issue&Volume: 2021-09-21

Abstract: Extracellular vesicles (EVs) transfer complex biologic material between cells. However,the role of this process in vivo is poorly defined. Here, we demonstrate that osteoblastic cells in the bone marrow(BM) niche elaborate extracellular vesicles that are taken up by hematopoietic progenitorcells in vivo. Genotoxic or infectious stress rapidly increased stromal-derived extracellular vesicletransfer to granulocyte-monocyte progenitors. The extracellular vesicles containedprocessed tRNAs (tiRNAs) known to modulate protein translation. 5′-ti-Pro-CGG-1 waspreferentially abundant in osteoblast-derived extracellular vesicles and, when transferredto granulocyte-monocyte progenitors, increased protein translation, cell proliferation,and myeloid differentiation. Upregulating EV transfer improved hematopoietic recoveryfrom genotoxic injury and survival from fungal sepsis. Therefore, EV-mediated tiRNAtransfer provides a stress-modulated signaling axis in the BM niche distinct fromconventional cytokine-driven stress responses.

DOI: 10.1016/j.stem.2021.08.014

Source: https://www.cell.com/cell-stem-cell/fulltext/S1934-5909(21)00351-9