Bradykinin enhances reactive oxygen species generation, mitochondrial injury, and cell death induced by ATP depletion--a role of the phospholipase C-Ca(2+) pathway.
This study aimed to study the effect of bradykinin on reactive oxygen species (ROS) generation, mitochondrial injury, and cell death induced by ATP depletion in cell culture. Renal tubular cells were subjected to ATP depletion. Cell death was evaluated with LDH release, sub-G0/G1 fraction, Hoechst staining, and annexin V binding assay. ROS generation, mitochondrial membrane potential (DeltaPsi(m)), and intramitochondrial calcium were evaluated with flow cytometry. Translocation of cytochrome c and activation of apoptotic protein were analyzed with cell fractionating and Western blotting. Intracellular calcium was measured with a spectrofluorometer. Bradykinin enhanced cellular LDH release, apoptosis, generation of superoxide, and hydrogen peroxide induced by ATP depletion. Bradykinin also enhanced the loss of DeltaPsi(m), translocation of cytochrome c into cytosol, and activation of apoptotic protein. The intracellular/mitochondrial calcium was higher in bradykinin-treated cells. All these effects were reversed by coadministration with bradykinin B2 receptor (B2R) antagonist. Besides, blocking the phospholipase C (PLC) could reverse the synergistic effect of bradykinin with ATP depletion on ROS generation, mitochondrial damage, accumulation of intracellular/mitochondrial calcium, and apoptosis. Activation of B2R aggravates ROS generation, mitochondrial damage, and cell death induced by ATP depletion. These effects may act through the PLC-Ca(2+) signaling pathway.
Department of Internal Medicine, National Taiwan University Hospital, No. 7, Jhongshan S. Rd., Taipei 10016, Taiwan.
Wen-Chih
WC
Chiang
Yung-Ming
YM
Chen
Shuei-Liong
SL
Lin
Kwan-Dun
KD
Wu
Tun-Jun
TJ
Tsai
D000255:Adenosine Triphosphate / Q000494:pharmacology*; D000818:Animals; D017304:Annexin A5 / Q000378:metabolism; D017209:Apoptosis / Q000187:drug effects; D001920:Bradykinin / Q000494:pharmacology*; D020013:Calcium Signaling / Q000187:drug effects*; D015687:Cell Hypoxia / Q000187:drug effects; D002460:Cell Line; D045304:Cytochromes c / Q000378:metabolism; D008928:Mitochondria / Q000187:drug effects* / Q000378:metabolism*; D051336:Mitochondrial Membranes / Q000378:metabolism; D011485:Protein Binding; D047428:Protein Kinase Inhibitors / Q000494:pharmacology; D051381:Rats; D017382:Reactive Oxygen Species / Q000378:metabolism*; D043782:Receptor, Bradykinin B2 / Q000378:metabolism; D010738:Type C Phospholipases / Q000037:antagonists & inhibitors / Q000378:metabolism*
D017304:Annexin A5; D047428:Protein Kinase Inhibitors; D017382:Reactive Oxygen Species; D043782:Receptor, Bradykinin B2; D000255:Adenosine Triphosphate; D045304:Cytochromes c; D010738:Type C Phospholipases; D001920:Bradykinin