Mitochondrial permeability transition mediates apoptosis induced by N-methyl(R)salsolinol, an endogenous neurotoxin, and is inhibited by Bcl-2 and rasagiline, N-propargyl-1(R)-aminoindan.
The role of mitochondrial permeability transition (PT) in apoptosis induced by an endogenous neurotoxin, N-methyl(R)salsolinol [NM(R)Sal], was studied by use of dopaminergic neuroblastoma SH-SY5Y cells. NM(R)Sal reduced mitochondrial membrane potential, DeltaPsim, in the early phase of apoptosis, which was not suppressed by a pan-caspase inhibitor, but was antagonized by Bcl-2 and cyclosporin A, suggesting the involvement of the PT in NM(R)Sal-induced loss of DeltaPsim. NM(R)Sal-induced apoptosis was completely inhibited not only by Bcl-2 and a pan-caspase inhibitor, but also by cyclosporin A, suggesting the essential role of the PT in NM(R)Sal-induced apoptosis. In mitochondria isolated from rat liver, NM(R)Sal induced swelling and reduced DeltaPsim, which was inhibited by cyclosporin A and Bcl-2 overexpression. These results indicate that NM(R)Sal induced the PT by direct action on the mitochondria. Rasagiline, N-propargyl-1(R)-aminoindan, which is a now under a clinical trial for Parkinson's disease, suppressed the DeltaPsim reduction, release of cytochrome c, and apoptosis induced by NM(R)Sal in SH-SY5Y cells. Rasagiline also inhibited the NM(R)Sal-induced loss of DeltaPsim and swelling in the isolated mitochondria, proving that rasagiline directly targets the mitochondria also. Altogether, mitochondrial PT plays a key role both in NM(R)Sal-induced cell death and the neuroprotective effect of rasagiline.
D000818:Animals; D017209:Apoptosis / Q000187:drug effects / Q000502:physiology*; D016572:Cyclosporine / Q000494:pharmacology; D004791:Enzyme Inhibitors / Q000494:pharmacology; D006801:Humans; D007189:Indans / Q000494:pharmacology*; D007473:Ion Channels / Q000187:drug effects* / Q000378:metabolism; D008930:Mitochondria, Liver / Q000737:chemistry / Q000187:drug effects / Q000378:metabolism; D033681:Mitochondrial Membrane Transport Proteins; D000083162:Mitochondrial Permeability Transition Pore; D009447:Neuroblastoma / Q000188:drug therapy / Q000378:metabolism; D018696:Neuroprotective Agents / Q000494:pharmacology; D009498:Neurotoxins / Q000494:pharmacology*; D010539:Permeability / Q000187:drug effects; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000235:genetics / Q000378:metabolism* / Q000494:pharmacology; D051381:Rats; D012490:Salsoline Alkaloids / Q000494:pharmacology*; D044005:Tetrahydroisoquinolines; D014407:Tumor Cells, Cultured
D004791:Enzyme Inhibitors; D007189:Indans; D007473:Ion Channels; D033681:Mitochondrial Membrane Transport Proteins; D000083162:Mitochondrial Permeability Transition Pore; D018696:Neuroprotective Agents; D009498:Neurotoxins; D019253:Proto-Oncogene Proteins c-bcl-2; D012490:Salsoline Alkaloids; D044005:Tetrahydroisoquinolines; C031967:rasagiline; D016572:Cyclosporine; C032837:salsoline