title: RhoA/ROCK1 regulates Avian Reovirus S1133-induced switch from autophagy to apoptosis.
abstract: BACKGROUND
  Autophagy is an essential process in the control of cellular homeostasis. It enables cells under certain stress conditions to survive by removing toxic cellular components, and may protect cells from apoptosis. In the present study, the signaling pathways involved in ARV S1133 regulated switch from autophagy to apoptosis were investigated.
  
  
  RESULTS
  ARV S1133 infection caused autophagy in the early to middle infectious stages in Vero and DF1 cells, and apoptosis in the middle to late stages. Conversion of the autophagy marker LC3-I to LC3-II occurred earlier than cleavage of the apoptotic marker caspase-3. ARV S1133 also activated the Beclin-1 promoter in the early to middle stages of infection. Levels of RhoA-GTP and ROCK1 activity were elevated upon ARV S1133 infection, while inhibition of RhoA and ROCK1 reduced autophagy and subsequent apoptosis. Conversely, inhibition of caspase-3 did not affect the level of autophagy. Beclin-1 knockdown and treatment with autophagy inhibitors, 3-MA and Bafilomycin A1, suppressed ARV S1133-induced autophagy and apoptosis simultaneously, suggesting the shift from autophagy to apoptosis. A co-immunoprecipitation assay demonstrated that the formation of a RhoA, ROCK1 and Beclin-1 complex coincided with the induction of autophagy.
  
  
  CONCLUSIONS
  Our results demonstrate that RhoA/ROCK1 signaling play critical roles in the transition of cell activity from autophagy to apoptosis in ARV S1133-infected cells.
authors.affiliation: Department of Biological Science and Technology, Pingtung, 91201, Taiwan. likelego1980@yahoo.com.tw.
authors.forename: Ping-Yuan
authors.initials: PY
authors.lastname: Lin
authors.affiliation: Veterinary Medicine, National Pingtung University of Science and Technology, Pingtung, Taiwan. cdchang@mail.npust.edu.tw.
authors.forename: Ching-Dong
authors.initials: CD
authors.lastname: Chang
authors.affiliation: Department of Biological Science and Technology, Pingtung, 91201, Taiwan. ox@mail.npust.edu.tw.
authors.forename: Yo-Chia
authors.initials: YC
authors.lastname: Chen
authors.affiliation: Department of Biological Science and Technology, Pingtung, 91201, Taiwan. wlshih@mail.npust.edu.tw.|Graduate Institute of Biotechnology, National Pingtung University of Science and Technology, 1, Shuefu Rd., Neipu, Pingtung, 91201, Taiwan. wlshih@mail.npust.edu.tw.
authors.forename: Wen-Ling
authors.initials: WL
authors.lastname: Shih
mesh_terms: D000577:Amides / Q000494:pharmacology; D000818:Animals; D017209:Apoptosis / Q000502:physiology*; D001343:Autophagy / Q000502:physiology*; D002645:Chickens; D002522:Chlorocebus aethiops; D005347:Fibroblasts / Q000378:metabolism* / Q000821:virology; D005786:Gene Expression Regulation / Q000187:drug effects / Q000502:physiology; D030101:Orthoreovirus, Avian / Q000145:classification / Q000502:physiology*; D011725:Pyridines / Q000494:pharmacology; D034622:RNA Interference; D034741:RNA, Small Interfering; D015398:Signal Transduction; D014709:Vero Cells; D054460:rho-Associated Kinases / Q000235:genetics / Q000378:metabolism*; D020742:rhoA GTP-Binding Protein / Q000235:genetics / Q000378:metabolism*
chemical_list: D000577:Amides; D011725:Pyridines; D034741:RNA, Small Interfering; C108830:Y 27632; D054460:rho-Associated Kinases; D020742:rhoA GTP-Binding Protein