{"doi":"10.1152/ajpheart.01063.2003","title":"Caspase-dependent cytochrome <i>c</i> release and cell death in chick cardiomyocytes after simulated ischemia-reperfusion","abstract":"<jats:p> We recently demonstrated that reperfusion rapidly induces the mitochondrial pathway of apoptosis in chick cardiomyocytes after 1 h of simulated ischemia. Here we tested whether ischemia-reperfusion (I/R)-induced apoptosis could be initiated by caspase-dependent cytochrome c release in this model of cardiomyocyte injury. Fluorometric assays of caspase activity showed little, if any, activation of caspases above baseline levels induced by 1 h of ischemia alone. However, these assays revealed rapid activation of caspase-2, yielding a 2.95 ± 0.52-fold increase (over ischemia only) within the 1st h of reperfusion, whereas activities of caspases-3, -8, and -9 increased only slightly from their baseline levels. The rapid and prominent activation of caspase-2 suggested that it could be an important initiator caspase in this model, and using specific caspase inhibitors given only at the point of reperfusion, we tested this hypothesis. The caspase-2 inhibitor benzyloxycarbonyl-Val-Asp(Ome)-Val-Ala-Asp(Ome)-CH<jats:sub>2</jats:sub>F was the only caspase inhibitor that significantly inhibited cytochrome c release from mitochondria. This inhibitor also completely blocked activation of caspases-3, -8, and -9. The caspase-3/7 inhibitor transiently and only partially blocked caspase-2 activity and was less effective in blocking the activities of caspases-8 and -9. The caspase-8 inhibitor failed to significantly block caspase-2 or -3, and the caspase-9 inhibitor blocked only caspase-9. Furthermore, the caspase-2 inhibitor protected against I/R-induced cell death, but the caspase-8 inhibitor failed to do so. These data suggest that active caspase-2 initiates cytochrome c release after reperfusion and that it is critical for the I/R-induced apoptosis in this model. </jats:p>","journal":"American Journal of Physiology-Heart and Circulatory Physiology","year":2004,"id":681396,"datarank":0.5775221402565088,"base_score":3.8501476017100584,"endowment":3.8501476017100584,"self_citation_contribution":0.5775221402565088,"citation_network_contribution":0.0,"self_endowment_contribution":0.5775221402565088,"citer_contribution":0.0,"corpus_percentile":null,"corpus_rank":null,"citation_count":46,"citer_count":0,"citers_with_citation_signal":0,"citers_with_endowment":0,"datacite_reuse_total":0,"is_dataset":false,"is_dataset_confidence":null,"is_data_producer":false,"deposit_databanks":null,"is_oa":false,"file_count":0,"downloads":0,"has_version_chain":false,"published_date":null,"fair_score":null,"fair_percentile":null,"algorithm_id":"datarank_citation_only_1hop_v6","ranking_scope":"data_only","authors":[{"id":547206,"name":"Terry L. Vanden Hoek","orcid":"0000-0002-1684-7850","position":1,"is_corresponding":false},{"id":1780286,"name":"Kim Wojcik","orcid":null,"position":2,"is_corresponding":false},{"id":1540575,"name":"Travis Anderson","orcid":null,"position":3,"is_corresponding":false},{"id":1780287,"name":"Chang-Qing Li","orcid":null,"position":4,"is_corresponding":false},{"id":1780288,"name":"Zuo-Hui Shao","orcid":null,"position":5,"is_corresponding":false},{"id":94672,"name":"Lance B. Becker","orcid":"0000-0001-7051-8778","position":6,"is_corresponding":false},{"id":1780289,"name":"Kimm J. Hamann","orcid":null,"position":7,"is_corresponding":false},{"id":1780285,"name":"Yimin Qin","orcid":null,"position":0,"is_corresponding":false}],"reference_count":0,"raw_metadata":{"has_enrichment":true,"resolved":true,"title":"Caspase-dependent cytochrome <i>c</i> release and cell death in chick cardiomyocytes after simulated ischemia-reperfusion","abstract":"<jats:p> We recently demonstrated that reperfusion rapidly induces the mitochondrial pathway of apoptosis in chick cardiomyocytes after 1 h of simulated ischemia. Here we tested whether ischemia-reperfusion (I/R)-induced apoptosis could be initiated by caspase-dependent cytochrome c release in this model of cardiomyocyte injury. Fluorometric assays of caspase activity showed little, if any, activation of caspases above baseline levels induced by 1 h of ischemia alone. However, these assays revealed rapid activation of caspase-2, yielding a 2.95 ± 0.52-fold increase (over ischemia only) within the 1st h of reperfusion, whereas activities of caspases-3, -8, and -9 increased only slightly from their baseline levels. The rapid and prominent activation of caspase-2 suggested that it could be an important initiator caspase in this model, and using specific caspase inhibitors given only at the point of reperfusion, we tested this hypothesis. The caspase-2 inhibitor benzyloxycarbonyl-Val-Asp(Ome)-Val-Ala-Asp(Ome)-CH<jats:sub>2</jats:sub>F was the only caspase inhibitor that significantly inhibited cytochrome c release from mitochondria. This inhibitor also completely blocked activation of caspases-3, -8, and -9. The caspase-3/7 inhibitor transiently and only partially blocked caspase-2 activity and was less effective in blocking the activities of caspases-8 and -9. The caspase-8 inhibitor failed to significantly block caspase-2 or -3, and the caspase-9 inhibitor blocked only caspase-9. Furthermore, the caspase-2 inhibitor protected against I/R-induced cell death, but the caspase-8 inhibitor failed to do so. These data suggest that active caspase-2 initiates cytochrome c release after reperfusion and that it is critical for the I/R-induced apoptosis in this model. </jats:p>","is_dataset_classified":null,"base_score":3.8501476017100584,"endowment":3.8501476017100584,"datacite_reuse_total":0,"file_count":0,"downloads":0,"views":0,"has_version_chain":false,"is_dataset":false,"is_oa":false,"pmid":"14975933","pmcid":null,"openalex_id":"https://openalex.org/W2111512232","authors":[],"funders":[{"funder_name":"NHLBI NIH HHS","grant_id":"R01 HL 65558","title":null},{"funder_name":"NHLBI NIH HHS","grant_id":"R01 HL 66026","title":null},{"funder_name":"NHLBI NIH HHS","grant_id":"R01 HL 68951","title":null}],"total_grants":3,"fwci":1.1353,"citation_percentile":0.75662948,"influential_citations":0,"citation_trend":[{"year":2012,"count":4},{"year":2013,"count":3},{"year":2014,"count":1},{"year":2015,"count":3},{"year":2016,"count":2},{"year":2017,"count":3},{"year":2018,"count":1},{"year":2020,"count":4},{"year":2021,"count":2},{"year":2022,"count":3},{"year":2023,"count":1},{"year":2024,"count":2}],"oa_status":"closed","license":null,"oa_locations":[{"url":"https://www.physiology.org/doi/pdf/10.1152/ajpheart.01063.2003","host_type":"publisher"},{"url":"https://doi.org/10.1152/ajpheart.01063.2003","host_type":"journal"},{"url":"https://pubmed.ncbi.nlm.nih.gov/14975933","host_type":"repository"}],"fields_of_study":["Cell death mechanisms and regulation","Mitochondrial Function and Pathology","Cardiac Ischemia and Reperfusion"],"mesh_terms":["Amino Acid Chloromethyl Ketones","Animals","Chick Embryo","Chickens","Oligopeptides","Myocardial Reperfusion Injury","Cysteine Proteinase Inhibitors","Apoptosis","Caspases","Myocytes, Cardiac","Cytochromes c","Caspase 2","Caspase 3","Caspase 8","Caspase 9","Caspase Inhibitors"],"keywords":["Caspase","Cytochrome c","Apoptosis","Caspase-9","Caspase 3","Caspase 2","Caspase 8","Cell biology","Programmed cell death","Ischemia","Molecular biology","Reperfusion injury","Chemistry","Pharmacology","Biology","Biochemistry","Medicine","Internal medicine"],"sdg_mappings":[{"sdg_number":0,"sdg_label":"Good health and well-being"}],"linked_datasets":[],"clinical_trials":[],"software_tools":[],"database_accessions":[],"source":"live","citation_network_status":"fetched"},"created_at":"2026-08-17T17:43:24.402282Z","pmid":null,"pmcid":null,"fwci":null,"citation_percentile":null,"influential_citations":0,"oa_status":null,"license":null,"views":0,"total_file_size_bytes":0,"version_count":0,"fair_f":null,"fair_a":null,"fair_i":null,"fair_r":null,"fair_zscore":null,"fair_rationale":null,"fair_model":null,"fair_agent_version":null,"fair_fulltext_source":null,"fair_has_llm":null,"fair_computed_at":null,"clinical_trials":[],"software_tools":[],"db_accessions":[],"linked_datasets":[],"topics":[]}