Tissue-specific autophagy responses to aging and stress in C. elegans.
Tissue-specific autophagy responses to aging and stress in C. elegans.
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DOI：
10.18632/aging.100765
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发表时间：
2015-06
期刊：
影响因子：
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通讯作者：
Miller DL
中科院分区：
文献类型：
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作者：
Chapin HC;Okada M;Merz AJ;Miller DL
细胞功能依赖于蛋白质合成和分解之间的平衡。通过自噬的大分子分解是细胞和组织发育、功能和从应激中恢复所广泛需要的。虽然秀丽隐杆线虫经常用于探索细胞对发育和应激的反应，但该系统中最常见的自噬测定缺乏组织水平的分辨率。生物体内的不同组织具有独特的功能特征，并且在不同条件下对自噬的依赖可能不同。在C.在elegans中，我们使用双荧光蛋白（dFP）标签，其在到达溶酶体时释放单体荧光蛋白（mFP）。dFP：：LGG-1的组织特异性表达揭示了所有组织中的自噬通量，但mFP积聚在肠中最显著。我们还观察到不同的应激反应：饥饿增加自噬mFP释放在所有组织中，而缺氧主要增加肠道自噬通量。我们观察了标记的LGG-1，LGG-2，和两个自噬货物报告：可溶性细胞质蛋白，和线粒体TOMM-7的自噬通量。最后，老年蠕虫中mFP的增加与蛋白质稳态的年龄依赖性变化一致。这些新的措施，自噬通量在C。elegans揭示了在应激和衰老过程中跨组织的自噬反应的异质性。
Cellular function relies on a balance between protein synthesis and breakdown. Macromolecular breakdown through autophagy is broadly required for cellular and tissue development, function, and recovery from stress. While Caenorhabditis elegans is frequently used to explore cellular responses to development and stress, the most common assays for autophagy in this system lack tissue-level resolution. Different tissues within an organism have unique functional characteristics and likely vary in their reliance on autophagy under different conditions. To generate a tissue-specific map of autophagy in C. elegans we used a dual fluorescent protein (dFP) tag that releases monomeric fluorescent protein (mFP) upon arrival at the lysosome. Tissue-specific expression of dFP::LGG-1 revealed autophagic flux in all tissues, but mFP accumulation was most dramatic in the intestine. We also observed variable responses to stress: starvation increased autophagic mFP release in all tissues, whereas anoxia primarily increased intestinal autophagic flux. We observed autophagic flux with tagged LGG-1, LGG-2, and two autophagic cargo reporters: a soluble cytoplasmic protein, and mitochondrial TOMM-7. Finally, an increase in mFP in older worms was consistent with an age-dependent shift in proteostasis. These novel measures of autophagic flux in C. elegans reveal heterogeneity in autophagic response across tissues during stress and aging.