Mitochondrial permeability transition pore complex (mPTP) (mPTP)

The Mitochondrial Permeability Transition Pore (mPTP) complex is a high-conductance, non-selective channel that forms across the inner and outer mitochondrial membranes in response to triggers such as calcium overload and oxidative stress [PubMed: 28213281]. Historically, the complex was defined by the interaction of the Voltage-Dependent Anion Channel (VDAC) in the outer membrane, the Adenine Nucleotide Translocase (ANT) in the inner membrane, and the Translocator Protein (TSPO, formerly known as the Peripheral Benzodiazepine Receptor or PBR), all regulated by the matrix protein Cyclophilin D (CypD) [PubMed: 25109572]. Although recent genetic studies suggest VDAC and TSPO may not be essential structural components of the pore itself, they remain critical regulatory elements that influence pore opening and mitochondrial function [PubMed: 24012443]. Opening of the mPTP leads to the collapse of the mitochondrial membrane potential, mitochondrial swelling, and the release of pro-apoptotic factors like cytochrome c, which initiates cell death pathways [PubMed: 19234182]. This process is a major driver of tissue damage in ischemia-reperfusion injury, such as myocardial infarction and stroke, and contributes to the progression of neurodegenerative diseases and muscular dystrophies [PubMed: 26331325]. Pharmacological strategies targeting the mPTP complex include CypD inhibitors like Cyclosporine A and its non-immunosuppressive derivatives, as well as TSPO ligands like TRO40303, which aim to prevent pore opening and preserve mitochondrial integrity [PubMed: 24403567].

Other names

Mitochondrial megachannelPTPMPTPVDAC-ANT-CypD complexPeripheral benzodiazepine receptor complexTranslocator protein (18 kDa) complexVoltage-dependent anion-selective channel protein 1 complex

Inhibition of mitochondrial permeability transition pore opening