Cloning of PaAtg8 and roles of autophagy in adaptation to starvation with respect to the fat body and midgut of the Amerian cockroach, Periplaneta americana
Cloning of PaAtg8 and roles of autophagy in adaptation to starvation with respect to the fat body and midgut of the Amerian cockroach, Periplaneta americana
复制标题
PaAtg8 的克隆以及自噬在美洲大蠊脂肪体和中肠饥饿适应中的作用
DOI：
10.1007/s00441-014-1802-3
复制
发表时间：
2014
影响因子：
3.6
通讯作者：
Moo Soo Park and Makio Takeda
中科院分区：
文献类型：
--
作者：
Uno T;Isoyama Y;Sakamoto K;Uno Y;Sakamoto K;Kanamaru K;Yamagata H;Takagi M;Mizoguchi A;Takeda M;Moo Soo Park and Makio Takeda
Starvation, in particular amino acid deprivation, induces autophagy in trophocytes (adipocytes), the major component of the fat body cell types, in the larvae ofDrosophila melanogaster. However, the fat body of cockroach has two additional cell types: urocytes depositing uric acid in urate vacuoles as a nitrogen resource and mycetocytes harboring an endosymbiont,Blattabacterium cuenoti, which can synthesize amino acids from the metabolites of the stored uric acid. These cells might complement the roles of autophagy in recycling amino acids in the fat body or other organs of cockroaches under starvation. We investigate the presence of autophagy in tissues such as the fat body and midgut of the American cockroach,Periplaneta americana, under starvation by immunoblotting with antibody against Atg8, a ubiquitin-like protein required for the formation of autophagosomes and by electron microscopy. Corresponding changes in acid phosphatase activity were also investigated as representing lysosome activity. Starvation increased the level of an autophagic marker, Atg8-II, in both the tissues, extensively stimulating the formation of autophagic compartments in trophocytes of the fat body and columnar cells of the midgut for over 2 weeks. Acid phosphatase showed no significant increase in the fat body of the starved cockroaches but was higher in the midgut of the continuously fed animals. Thus, a distinct autophagic mechanism operates in these tissues under starvation of 2 weeks and longer. The late induction of autophagy implies exhaustion of the stored uric acid in the fat body. High activity of acid phosphatase in the midgut of the fed cockroaches might represent enhanced assimilation and not an autophagy-related function.
