title: Apoptosis phenomenon in the schistosomulum and adult worm life cycle stages of Schistosoma japonicum.
abstract: Apoptosis is an important aspect of a number of biological processes, from embryogenesis to the stress-injury response. It plays a central role in balancing cell proliferation and tissue remodeling activity in many organisms. In the present study, apoptosis in 14 days post infection schistosomula was evaluated using TUNEL (terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling) assays and DAPI staining. Additionally, flow cytometry using the Annexin V-FITC/propidium iodide (PI) (Annexin V/PI) assay confirmed the percentage of early apoptotic, late apoptotic, and necrotic cells in 14 and 23 days post infection worms. Conserved Domain Database (CDD) BLAST analysis and alignment analysis of known schistosome proteins demonstrated the feasibility of detecting the activity of caspase-3 and -7 using the caspase-3/7 Glo analysis assay. Analysis of caspase-3 and -7 activities in schistosome demonstrated that both caspases were active in each developmental stage of Schistosoma japonicum, but was highest in the 14 days post infection schistosomula. Additionally, the caspase peptide inhibitor (Z-VAD-FMK) inhibited the caspase-3/7 activity at all developmental stages examined. Therefore, we hypothesized that two main signaling pathways are involved in apoptosis in S. japonicum, the caspase cascade and the mitochondrial-initiated pathway. We have constructed a model of these two pathways, including how they may interact and their biological outcomes. qRT-PCR analyses of the gene expression profiles of apoptosis-related genes supported our hypothesis of the relationship between the apoptotic pathway and parasite development. The data presented here demonstrates that apoptosis is an important biological process for the survival and development of the schistosome, and identifies potential novel therapeutic targets.
authors.affiliation: College of Veterinary Medicine, Yangzhou University, 12 East Wenhui Road, Yangzhou, Jiangsu, China.
authors.forename: Hongxiao
authors.initials: H
authors.lastname: Han
authors.forename: Jinbiao
authors.initials: J
authors.lastname: Peng
authors.forename: Geoffrey N
authors.initials: GN
authors.lastname: Gobert
authors.forename: Yang
authors.initials: Y
authors.lastname: Hong
authors.forename: Min
authors.initials: M
authors.lastname: Zhang
authors.forename: Yanhui
authors.initials: Y
authors.lastname: Han
authors.forename: Zhiqiang
authors.initials: Z
authors.lastname: Fu
authors.forename: Yaojun
authors.initials: Y
authors.lastname: Shi
authors.forename: Jinjun
authors.initials: J
authors.lastname: Xu
authors.forename: Jiaojiao
authors.initials: J
authors.lastname: Lin
authors.forename: Jianping
authors.initials: J
authors.lastname: Tao
mesh_terms: D000590:Amino Acid Chloromethyl Ketones / Q000494:pharmacology; D000595:Amino Acid Sequence; D000818:Animals; D017209:Apoptosis / Q000502:physiology*; D053148:Caspase 3 / Q000187:drug effects / Q000378:metabolism; D053179:Caspase 7 / Q000187:drug effects / Q000378:metabolism; D061945:Caspase Inhibitors / Q000494:pharmacology; D002470:Cell Survival; D005260:Female; D005786:Gene Expression Regulation; D015801:Helminth Proteins / Q000187:drug effects / Q000378:metabolism*; D008018:Life Cycle Stages; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D008958:Models, Molecular; D012549:Schistosoma japonicum / Q000166:cytology / Q000187:drug effects / Q000254:growth & development* / Q000502:physiology; D012554:Schistosomiasis japonica / Q000469:parasitology*; D016415:Sequence Alignment; D015398:Signal Transduction; D013047:Specific Pathogen-Free Organisms
chemical_list: D000590:Amino Acid Chloromethyl Ketones; D061945:Caspase Inhibitors; D015801:Helminth Proteins; C096713:benzyloxycarbonylvalyl-alanyl-aspartyl fluoromethyl ketone; D053148:Caspase 3; D053179:Caspase 7