Lee Yuan-Ming, Sun Y Henry
Institute of Molecular Biology, Academia Sinica, Taipei, Taiwan; Institute of Genomic Sciences, National Yang-Ming University, Taipei, Taiwan.
PLoS Genet. 2015 Apr 24;11(4):e1005187. doi: 10.1371/journal.pgen.1005187. eCollection 2015 Apr.
The late onset of neurodegeneration in humans indicates that the survival and function of cells in the nervous system must be maintained throughout adulthood. In the optic lamina of the adult Drosophila, the photoreceptor axons are surrounded by multiple types of glia. We demonstrated that the adult photoreceptors actively contribute to glia maintenance in their target field within the optic lamina. This effect is dependent on the epidermal growth factor receptor (EGFR) ligands produced by the R1-6 photoreceptors and transported to the optic lamina to act on EGFR in the lamina glia. EGFR signaling is necessary and sufficient to act in a cell-autonomous manner in the lamina glia. Our results suggest that EGFR signaling is required for the trafficking of the autophagosome/endosome to the lysosome. The loss of EGFR signaling results in cell degeneration most likely because of the accumulation of autophagosomes. Our findings provide in vivo evidence for the role of adult neurons in the maintenance of glia and a novel role for EGFR signaling in the autophagic flux.
人类神经退行性变的迟发性表明，神经系统中细胞的存活和功能必须在整个成年期得到维持。在成年果蝇的视叶中，光感受器轴突被多种类型的神经胶质细胞所包围。我们证明，成年光感受器在视叶内其靶区域中积极参与神经胶质细胞的维持。这种作用依赖于由R1-6光感受器产生并转运至视叶以作用于视叶神经胶质细胞中表皮生长因子受体（EGFR）的配体。EGFR信号传导对于视叶神经胶质细胞以细胞自主方式发挥作用是必要且充分的。我们的结果表明，EGFR信号传导对于自噬体/内体向溶酶体的运输是必需的。EGFR信号传导的丧失最有可能由于自噬体的积累而导致细胞变性。我们的发现为成年神经元在神经胶质细胞维持中的作用提供了体内证据，并为EGFR信号传导在自噬流中的新作用提供了证据。
