College of Food Science and Technology, Hunan Agricultural University, Changsha, China.
Horticulture and Landscape College, Hunan Agricultural University, Changsha, China.
Acta Biochim Biophys Sin (Shanghai). 2018 Nov 1;50(11):1085-1093. doi: 10.1093/abbs/gmy114.
Organosulfur compounds (OSCs) are the bioactive components of garlic. Some OSCs have apoptotic or autophagy-inducing effects. Autophagy plays roles in both cytoprotection and apoptosis-related cell death, and the interaction between autophagy and apoptosis is important in the modulation of immune responses. The mechanism of an OSC-mediated effect via the interaction of autophagy and apoptosis is unknown. In this study, the effects of five OSC compounds on autophagy in the macrophage cell line RAW264.7 and primary macrophages were investigated. We found that S-allylcysteine (SAC), diallyl disulde (DADS) and diallyl tetrasulfide (DTS) treatment increased the number of autophagosomes of RAW264.7 cells, inhibited the phosphorylation of ribosomal protein S6 kinase beta-1 (p70S6K/S6K1) which is a substrate of mammalian target of rapamycin (mTOR), and significantly enhanced autophagy flux. The induction of autophagy by SAC, DADS and DTS was inhibited by stably knocking down the expression of autophagy-related gene 5 (ATG5) with short hairpin RNA (shRNA). Further experiments confirmed that SAC, DADS and DTS also induced apoptosis in RAW264.7 cells. The induction of apoptosis and Caspase 3 activity by SAC, DADS and DTS were increased by stably knocking down of ATG5 expression with shRNA in RAW264.7 cells or treating with 5 mM 3-MA in primary macrophages. Our results suggest that SAC, DADS and DTS induce both autophagy and apoptosis. The autophagy induction protects macrophages from apoptosis by inhibiting mTOR phosphorylation activity to maintain the mass of immune cells.
有机硫化合物（OSCs）是大蒜中的生物活性成分。一些 OSCs 具有凋亡或自噬诱导作用。自噬在细胞保护和凋亡相关细胞死亡中都发挥作用，自噬和凋亡之间的相互作用在免疫反应的调节中很重要。OSC 通过自噬和凋亡的相互作用介导作用的机制尚不清楚。在这项研究中，研究了五种 OSC 化合物对 RAW264.7 巨噬细胞系和原代巨噬细胞中自噬的影响。我们发现，S-烯丙半胱氨酸（SAC）、二烯丙基二硫（DADS）和二烯丙基四硫（DTS）处理增加了 RAW264.7 细胞自噬体的数量，抑制了核糖体蛋白 S6 激酶β-1（p70S6K/S6K1）的磷酸化，该蛋白是哺乳动物雷帕霉素靶蛋白（mTOR）的底物，并显著增强了自噬流。SAC、DADS 和 DTS 诱导的自噬被短发夹 RNA（shRNA）稳定敲低自噬相关基因 5（ATG5）的表达所抑制。进一步的实验证实，SAC、DADS 和 DTS 也诱导了 RAW264.7 细胞的凋亡。SAC、DADS 和 DTS 诱导的凋亡和 Caspase 3 活性通过稳定敲低 RAW264.7 细胞中的 ATG5 表达或用 5 mM 3-MA 处理原代巨噬细胞而增加。我们的结果表明，SAC、DADS 和 DTS 诱导自噬和凋亡。自噬诱导通过抑制 mTOR 磷酸化活性来保护巨噬细胞免于凋亡，以维持免疫细胞的质量。
