Lim Yi Shan, Tang Bor Luen
Department of Biochemistry, Yong Loo Lin School of Medicine, National University Health System, National University of Singapore, 8 Medical Drive, Singapore 117597.
Cell Commun Adhes. 2012 Aug;19(3-4):39-44. doi: 10.3109/15419061.2012.712574. Epub 2012 Sep 4.
Cells could make actin-based filopodial extensions that connect up with other cells. Such close-ended, actin-based filopodial bridges, or cytonemes, have been observed during developmental and pathological processes. On the other hand, tunneling nanotubes (TNTs) form conduits with open ends that allow transfer of cytoplasmic materials and organelles between cells. The past years have witnessed the description of TNTs in multiple cell types, with a range of interesting physiological and pathophysiological activities. Some hints of the molecular components that drive their formations are now emerging. Recent work has further suggested that TNTs could be important in regenerative transfer of large cellular components, including organelles such as mitochondria and lysosomes between senescing and younger cell types (at least for cells in culture). These findings have intriguing implications in cell biology and regenerative medicine.
细胞能够形成基于肌动蛋白的丝状伪足延伸，与其他细胞相连。这种封闭的、基于肌动蛋白的丝状伪足桥，即细胞线，已在发育和病理过程中被观察到。另一方面，隧道纳米管（TNTs）形成两端开放的管道，允许细胞间细胞质物质和细胞器的转移。过去几年见证了多种细胞类型中TNTs的描述，以及一系列有趣的生理和病理生理活动。目前正在出现一些驱动其形成的分子成分的线索。最近的研究进一步表明，TNTs在大细胞成分的再生转移中可能很重要，包括衰老细胞和年轻细胞类型之间的线粒体和溶酶体等细胞器（至少对于培养中的细胞）。这些发现对细胞生物学和再生医学具有有趣的意义。
