title: Doxorubicin treatment in vivo activates caspase-12 mediated cardiac apoptosis in both male and female rats.
abstract: We investigated in vivo the chemotherapeutic anthracycline agents doxorubicin and its ability to activate mitochondrial-mediated, receptor-mediated and endoplasmic/sarcoplasmic reticulum-mediated apoptosis transduction pathways in cardiac tissue from male and female rats. We administered a single low dose of doxorubicin (10 mg/kg of body weight, i.p.) and then isolated mitochondrial and cytosolic proteins one and four days later from the heart. Caspase-3 protein content and caspase-3 activity were significantly increased after day four of doxorubicin treatment in both male and female rats. However, while males had DNA fragmentation at day one but not day four following doxorubicin administration, females showed no significant increase in DNA fragmentation at either time. Caspase-12, localized in the SR, is considered a central caspase, and its activation by cleavage via calpain indicates activation of the SR-mediated pathway of apoptosis. Cleaved caspase-12 content and calpain activity significantly increased after day four of doxorubicin treatment in both sexes. In the mitochondrial-mediated pathway, there were no significant treatment effects observed in cytosolic cytochrome c and cleaved (active) caspase-9 in either sex. In control rats (saline injection), glutathione peroxidase (GPX) activity and hydrogen peroxide (H2O2) production were lower in females compared to males. Doxorubicin treatment did not significantly affect H2O2, GPX activity or ATP production in isolated mitochondria in either sex. Female rats produced significantly lower levels of H2O2 production one day after doxorubicin treatment, whereas male rats produced significantly less mitochondrial H2O2 four days after doxorubicin treatment. The receptor-mediated pathway (caspase-8 and c-FLIP) showed no evidence of being significantly activated by doxorubicin treatment. Hence, doxorubicin-induced apoptosis in vivo is mediated by the SR to a greater extent than other apoptotic pathways and should therefore be considered for targeted therapeutic interventions. Moreover, no major sex differences exist in apoptosis signaling transduction cascade due to doxorubicin treatment.
authors.affiliation: Biochemistry of Aging Laboratory, University of Florida, P.O. Box 118206, Gainesville, FL 32611, USA.
authors.forename: Young Mok
authors.initials: YM
authors.lastname: Jang
authors.forename: Suma
authors.initials: S
authors.lastname: Kendaiah
authors.forename: Barry
authors.initials: B
authors.lastname: Drew
authors.forename: Tracey
authors.initials: T
authors.lastname: Phillips
authors.forename: Colin
authors.initials: C
authors.lastname: Selman
authors.forename: David
authors.initials: D
authors.lastname: Julian
authors.forename: Christiaan
authors.initials: C
authors.lastname: Leeuwenburgh
mesh_terms: D000818:Animals; D000903:Antibiotics, Antineoplastic / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects*; D015153:Blotting, Western; D001835:Body Weight / Q000187:drug effects; D002154:Calpain / Q000032:analysis / Q000378:metabolism; D053454:Caspase 12; D020169:Caspases / Q000187:drug effects*; D045304:Cytochromes c / Q000032:analysis / Q000378:metabolism; D003600:Cytosol / Q000737:chemistry; D004317:Doxorubicin / Q000494:pharmacology*; D004721:Endoplasmic Reticulum / Q000378:metabolism; D004789:Enzyme Activation; D004797:Enzyme-Linked Immunosorbent Assay; D004958:Estradiol / Q000097:blood / Q000378:metabolism; D005260:Female; D005979:Glutathione Peroxidase / Q000032:analysis / Q000378:metabolism; D006352:Heart Ventricles / Q000166:cytology; D008297:Male; D008929:Mitochondria, Heart / Q000737:chemistry / Q000378:metabolism; D008954:Models, Biological; D009929:Organ Size / Q000187:drug effects; D051381:Rats; D011916:Rats, Inbred F344; D012519:Sarcoplasmic Reticulum / Q000378:metabolism; D012737:Sex Factors; D015398:Signal Transduction; D013997:Time Factors
chemical_list: D000903:Antibiotics, Antineoplastic; D004958:Estradiol; D004317:Doxorubicin; D045304:Cytochromes c; D005979:Glutathione Peroxidase; D002154:Calpain; C506443:Casp12 protein, rat; D053454:Caspase 12; D020169:Caspases