title: The heat shock protein 27 (Hsp27) operates predominantly by blocking the mitochondrial-independent/extrinsic pathway of cellular apoptosis.
abstract: Heat shock protein 27 (Hsp27) is a molecular chaperone protein which regulates cell apoptosis by interacting directly with the caspase activation components in the apoptotic pathways. With the assistance of the Tat protein transduction domain we directly delivered the Hsp27 into the myocardial cell line, H9c2 and demonstrate that this protein can reverse hypoxia-induced apoptosis of cells. In order to characterize the contribution of Hsp27 in blocking the two major apoptotic pathways operational within cells, we exposed H9c2 cells to staurosporine and cobalt chloride, agents that induce mitochondria-dependent (intrinsic) and -independent (extrinsic) pathways of apoptosis in cells respectively. The Tat-Hsp27 fusion protein showed a greater propensity to inhibit the effect induced by the cobalt chloride treatment. These data suggest that the Hsp27 predominantly exerts its protective effect by interfering with the components of the extrinsic pathway of apoptosis.
authors.affiliation: Department of Bioengineering, Hanyang University, Seoul 133-791, Korea.
authors.forename: Cheau Yih
authors.initials: CY
authors.lastname: Tan
authors.forename: Hongseok
authors.initials: H
authors.lastname: Ban
authors.forename: Yong-Hee
authors.initials: YH
authors.lastname: Kim
authors.forename: Young-Hee
authors.initials: YH
authors.lastname: Kim
authors.forename: Sang-Kyung
authors.initials: SK
authors.lastname: Lee
mesh_terms: D017209:Apoptosis / Q000187:drug effects / Q000235:genetics; D051017:Apoptosis Regulatory Proteins / Q000235:genetics / Q000276:immunology / Q000378:metabolism*; D020169:Caspases / Q000235:genetics / Q000276:immunology / Q000378:metabolism*; D002460:Cell Line; D003035:Cobalt / Q000494:pharmacology; D019610:Cytoprotection; D015696:Gene Products, tat / Q000235:genetics / Q000276:immunology / Q000378:metabolism*; D055551:HSP27 Heat-Shock Proteins / Q000235:genetics / Q000276:immunology* / Q000378:metabolism; D006801:Humans; D000860:Hypoxia / Q000378:metabolism; D008929:Mitochondria, Heart / Q000187:drug effects / Q000378:metabolism; D009206:Myocardium / Q000276:immunology / Q000378:metabolism* / Q000473:pathology; D011993:Recombinant Fusion Proteins / Q000276:immunology / Q000378:metabolism*; D019311:Staurosporine / Q000494:pharmacology; D014161:Transduction, Genetic
chemical_list: D051017:Apoptosis Regulatory Proteins; D015696:Gene Products, tat; D055551:HSP27 Heat-Shock Proteins; D011993:Recombinant Fusion Proteins; C582517:TAT-HSP27 fusion protein, human; D003035:Cobalt; D020169:Caspases; C018021:cobaltous chloride; D019311:Staurosporine