Mitochondria in eosinophils: functional role in apoptosis but not respiration.
In most eukaryotic cells, mitochondria use the respiratory chain to produce a proton gradient, which is then harnessed for the synthesis of ATP. Recently, mitochondrial roles in regulation of apoptosis have been discovered in many cell types. Eosinophils (Eos) die by apoptosis, but the presence and function of mitochondria in Eos are unknown. This study found that Eos contain mitochondria in small numbers, as shown by labeling with membrane potential-sensitive dyes and in situ PCR for a mitochondrial gene. Eos generate mitochondrial membrane potential from hydrolysis of ATP rather than from respiration, as shown by mitochondrial respiratory inhibitors and mitochondrial uncouplers. The mitochondria provide insignificant respiration but can induce apoptosis, as shown by using the mitochondrial F(1)F(0)-ATPase inhibitor oligomycin and translocation of cytochrome c. Thus during differentiation of Eos, although respiration is lost, the other central role of mitochondria, the induction of apoptosis, is retained.
Peachman
K K
KK
Department of Microbiology and Immunology, Wake Forrest University School of Medicine, Medical Center Boulevard, Winston-Salem, NC 27157-1054, USA.
Lyles
D S
DS
Bass
D A
DA
D017209:Apoptosis; D003574:Cytochrome c Group / Q000378:metabolism; D004579:Electron Transport / Q000502:physiology; D003576:Electron Transport Complex IV / Q000235:genetics / Q000378:metabolism* / Q000502:physiology; D004804:Eosinophils / Q000166:cytology* / Q000378:metabolism / Q000502:physiology; D005456:Fluorescent Dyes; D006801:Humans; D008928:Mitochondria / Q000378:metabolism / Q000502:physiology*; D009930:Organic Chemicals; D010101:Oxygen Consumption / Q000502:physiology; D006180:Proton-Translocating ATPases / Q000378:metabolism* / Q000502:physiology; D014407:Tumor Cells, Cultured
D003574:Cytochrome c Group; D005456:Fluorescent Dyes; D009930:Organic Chemicals; C107472:red dye CMXRos; D003576:Electron Transport Complex IV; D006180:Proton-Translocating ATPases