title: Involvement of Lysosome Membrane Permeabilization and Reactive Oxygen Species Production in the Necrosis Induced by Chlamydia muridarum Infection in L929 Cells.
abstract: Chlamydiae, obligate intracellular bacteria, are associated with a variety of human diseases. The chlamydial life cycle undergoes a biphasic development: replicative reticulate bodies (RBs) phase and infectious elementary bodies (EBs) phase. At the end of the chlamydial intracellular life cycle, EBs have to be released to the surrounded cells. Therefore, the interactions between Chlamydiae and cell death pathways could greatly influence the outcomes of Chlamydia infection. However, the underlying molecular mechanisms remain elusive. Here, we investigated host cell death after Chlamydia infection in vitro, in L929 cells, and showed that Chlamydia infection induces cell necrosis, as detected by the propidium iodide (PI)-Annexin V double-staining flow-cytometric assay and Lactate dehydrogenase (LDH) release assay. The production of reactive oxygen species (ROS), an important factor in induction of necrosis, was increased after Chlamydia infection, and inhibition of ROS with specific pharmacological inhibitors, diphenylene iodonium (DPI) or butylated hydroxyanisole (BHA), led to significant suppression of necrosis. Interestingly, live-cell imaging revealed that Chlamydia infection induced lysosome membrane permeabilization (LMP). When an inhibitor upstream of LMP, CA-074-Me, was added to cells, the production of ROS was reduced with concomitant inhibition of necrosis. Taken together, our results indicate that Chlamydia infection elicits the production of ROS, which is dependent on LMP at least partially, followed by induction of host-cell necrosis. To our best knowledge, this is the first live-cell-imaging observation of LMP post Chlamydia infection and report on the link of LMP to ROS to necrosis during Chlamydia infection.
authors.affiliation: Shanghai Public Health Clinical Center, Key Laboratory of Medical Molecular Virology, MOE/MOH, Fudan Univeristy, Shanghai 201508, P.R. China.
authors.forename: Lixiang
authors.initials: L
authors.lastname: Chen
authors.affiliation: Shanghai Public Health Clinical Center, Key Laboratory of Medical Molecular Virology, MOE/MOH, Fudan Univeristy, Shanghai 201508, P.R. China.
authors.forename: Cong
authors.initials: C
authors.lastname: Wang
authors.affiliation: Shanghai Public Health Clinical Center, Key Laboratory of Medical Molecular Virology, MOE/MOH, Fudan Univeristy, Shanghai 201508, P.R. China.
authors.forename: Shun
authors.initials: S
authors.lastname: Li
authors.affiliation: Shanghai Public Health Clinical Center, Key Laboratory of Medical Molecular Virology, MOE/MOH, Fudan Univeristy, Shanghai 201508, P.R. China.
authors.forename: Xin
authors.initials: X
authors.lastname: Yu
authors.affiliation: Shanghai Public Health Clinical Center, Key Laboratory of Medical Molecular Virology, MOE/MOH, Fudan Univeristy, Shanghai 201508, P.R. China.
authors.forename: Xue
authors.initials: X
authors.lastname: Liu
authors.affiliation: Shanghai Public Health Clinical Center, Key Laboratory of Medical Molecular Virology, MOE/MOH, Fudan Univeristy, Shanghai 201508, P.R. China.
authors.forename: Rongrong
authors.initials: R
authors.lastname: Ren
authors.affiliation: Affiliated Hospital of Chifeng University, Chifeng 024000, P.R. China.
authors.forename: Wenwen
authors.initials: W
authors.lastname: Liu
authors.affiliation: The First Affiliated Hospital of Bengbu Medical College, Bengbu 233004, P.R. China.
authors.forename: Xiaojing
authors.initials: X
authors.lastname: Zhou
authors.affiliation: Shanghai Public Health Clinical Center, Key Laboratory of Medical Molecular Virology, MOE/MOH, Fudan Univeristy, Shanghai 201508, P.R. China.
authors.forename: Xiaonan
authors.initials: X
authors.lastname: Zhang
authors.affiliation: Shanghai Public Health Clinical Center, Key Laboratory of Medical Molecular Virology, MOE/MOH, Fudan Univeristy, Shanghai 201508, P.R. China.
authors.forename: Xiaohui
authors.initials: X
authors.lastname: Zhou
mesh_terms: D002083:Butylated Hydroxyanisole / Q000494:pharmacology; D016923:Cell Death; D002460:Cell Line; D023502:Chlamydia muridarum / Q000502:physiology* / Q000648:ultrastructure; D005434:Flow Cytometry; D006801:Humans; D007425:Intracellular Membranes / Q000502:physiology*; D007770:L-Lactate Dehydrogenase / Q000378:metabolism; D008247:Lysosomes / Q000473:pathology / Q000502:physiology*; D009336:Necrosis / Q000382:microbiology; D009861:Onium Compounds / Q000494:pharmacology; D061848:Optical Imaging; D011419:Propidium / Q000378:metabolism; D017382:Reactive Oxygen Species / Q000037:antagonists & inhibitors / Q000378:metabolism*
chemical_list: D009861:Onium Compounds; D017382:Reactive Oxygen Species; D002083:Butylated Hydroxyanisole; D011419:Propidium; C007517:diphenyleneiodonium; D007770:L-Lactate Dehydrogenase
keywords: Chlamydia; Lysosome Membrane Permeabilization; Necrosis; Reactive Oxygen Species Production