Department of Genetics, Graduate School of Medicine, Osaka University, Osaka, Japan.
EMBO J. 2013 Aug 28;32(17):2336-47. doi: 10.1038/emboj.2013.171. Epub 2013 Aug 6.
Diverse causes, including pathogenic invasion or the uptake of mineral crystals such as silica and monosodium urate (MSU), threaten cells with lysosomal rupture, which can lead to oxidative stress, inflammation, and apoptosis or necrosis. Here, we demonstrate that lysosomes are selectively sequestered by autophagy, when damaged by MSU, silica, or the lysosomotropic reagent L-Leucyl-L-leucine methyl ester (LLOMe). Autophagic machinery is recruited only on damaged lysosomes, which are then engulfed by autophagosomes. In an autophagy-dependent manner, low pH and degradation capacity of damaged lysosomes are recovered. Under conditions of lysosomal damage, loss of autophagy causes inhibition of lysosomal biogenesis in vitro and deterioration of acute kidney injury in vivo. Thus, we propose that sequestration of damaged lysosomes by autophagy is indispensable for cellular and tissue homeostasis.
多种原因,包括病原体入侵或矿物质晶体(如二氧化硅和单钠尿酸盐)的摄取,都会使细胞受到溶酶体破裂的威胁,从而导致氧化应激、炎症、细胞凋亡或坏死。在这里,我们证明了当溶酶体受到单钠尿酸盐、二氧化硅或溶酶体趋向性试剂 L-亮氨酰-L-亮氨酸甲酯(LLOMe)破坏时,溶酶体可以被自噬体选择性隔离。自噬机制仅在受损的溶酶体上被招募,然后这些溶酶体被自噬体吞噬。以自噬依赖性的方式,受损溶酶体的低 pH 值和降解能力得到恢复。在溶酶体受损的情况下,自噬的缺失会导致体外溶酶体生物发生的抑制和体内急性肾损伤的恶化。因此,我们提出,自噬体对受损溶酶体的隔离对于细胞和组织的内稳态是必不可少的。