title: BmCalpains are involved in autophagy and apoptosis during metamorphosis and after starvation in Bombyx mori.
abstract: Apoptosis and autophagy play crucial roles during Bombyx mori metamorphosis and in response to various adverse conditions, including starvation. Recently, calpain, one of the major intracellular proteases, has been reported to be involved in apoptosis and autophagy in mammals. BmATG5 and BmATG6 have been identified to mediate apoptosis following autophagy induced by 20-hydroxyecdysone and starvation in B. mori. However, B. mori calpains and their functions remain unclear. In this study, phylogenetic analysis of calpains from B. mori, Drosophila melanogaster and Homo sapiens were performed and the results showed distinct close relationships of BmCalpain-A/B with DmCalpain-A/B, BmCalpain-C with DmCalpain-C, and BmCalpain-7 with HsCalpain-7. Then, the expression profiles of BmCalpains were analyzed by quantitative real-time polymerase chain reaction, and results showed that expression of BmCalpain-A/B, BmCalpain-C and BmCalpain-7 was significantly increased during B. mori metamorphosis and induced in the fat body and midgut of starved larvae, which is consistent with the expression profiles of BmAtg5, BmAtg6 and BmCaspase-1. Moreover, the apoptosis-associated cleavage of BmATG6 in Bm-12 cells was significantly enhanced when BmCalpain-A/B and BmCalpain-7 were induced by starvation, and was partially inhibited by the inhibitor of either calpain or caspase, but completely inhibited when both types of inhibitors were applied together. Our results indicated that BmCalpains, including BmCalpain-A/B, -C and -7, may be involved in autophagy and apoptosis during B. mori metamorphosis and after starvation, and may also contribute to the apoptosis-associated cleavage of BmATG6.
authors.affiliation: Guangdong Provincial Key Laboratory of Agro-animal Genomics and Molecular Breeding/Guangdong Provincial Sericulture and Mulberry Engineering Research Center, College of Animal Science, South China Agricultural University, Guangzhou, China.|College of Life Science and Technology, Jinan University, Guangzhou, China.
authors.forename: Hui-Yu
authors.initials: HY
authors.lastname: Yi
authors.affiliation: Guangdong Provincial Key Laboratory of Agro-animal Genomics and Molecular Breeding/Guangdong Provincial Sericulture and Mulberry Engineering Research Center, College of Animal Science, South China Agricultural University, Guangzhou, China.
authors.forename: Wan-Ying
authors.initials: WY
authors.lastname: Yang
authors.affiliation: Guangdong Provincial Key Laboratory of Agro-animal Genomics and Molecular Breeding/Guangdong Provincial Sericulture and Mulberry Engineering Research Center, College of Animal Science, South China Agricultural University, Guangzhou, China.
authors.forename: Wen-Mei
authors.initials: WM
authors.lastname: Wu
authors.affiliation: Guangdong Provincial Key Laboratory of Agro-animal Genomics and Molecular Breeding/Guangdong Provincial Sericulture and Mulberry Engineering Research Center, College of Animal Science, South China Agricultural University, Guangzhou, China.
authors.forename: Xing-Xia
authors.initials: XX
authors.lastname: Li
authors.affiliation: Guangdong Provincial Key Laboratory of Agro-animal Genomics and Molecular Breeding/Guangdong Provincial Sericulture and Mulberry Engineering Research Center, College of Animal Science, South China Agricultural University, Guangzhou, China.
authors.forename: Xiao-Juan
authors.initials: XJ
authors.lastname: Deng
authors.affiliation: The Sericultural and Agri-Food Research Institute of the Guangdong Academy of Agricultural Sciences, Guangzhou, China.
authors.forename: Qing-Rong
authors.initials: QR
authors.lastname: Li
authors.affiliation: Guangdong Provincial Key Laboratory of Agro-animal Genomics and Molecular Breeding/Guangdong Provincial Sericulture and Mulberry Engineering Research Center, College of Animal Science, South China Agricultural University, Guangzhou, China.
authors.forename: Yang
authors.initials: Y
authors.lastname: Cao
authors.affiliation: Guangdong Provincial Key Laboratory of Agro-animal Genomics and Molecular Breeding/Guangdong Provincial Sericulture and Mulberry Engineering Research Center, College of Animal Science, South China Agricultural University, Guangzhou, China.
authors.forename: Yang-Jin
authors.initials: YJ
authors.lastname: Zhong
authors.affiliation: College of Life Science and Technology, Jinan University, Guangzhou, China.
authors.forename: Ya-Dong
authors.initials: YD
authors.lastname: Huang
mesh_terms: D000818:Animals; D017209:Apoptosis; D001343:Autophagy; D012831:Bombyx / Q000502:physiology*; D002154:Calpain / Q000235:genetics* / Q000378:metabolism; D061945:Caspase Inhibitors; D002460:Cell Line; D005216:Fat Body / Q000378:metabolism; D019476:Insect Proteins / Q000235:genetics / Q000378:metabolism; D008675:Metamorphosis, Biological; D010802:Phylogeny; D013217:Starvation / Q000378:metabolism*
chemical_list: D061945:Caspase Inhibitors; D019476:Insect Proteins; D002154:Calpain
keywords: BmATG6; Bombyx mori; apoptosis; autophagy; calpain; starvation