Video Experimental Relacionado
Updated: May 5, 2026
13:42
Multi-parameter Measurement of the Permeability Transition Pore Opening in Isolated Mouse Heart Mitochondria
Published on: September 7, 2012
20.9K
La transitoriedad de la permeabilidad mitocondrial, la transición de la apertura de los poros y la mediación de la
Derek Hausenloy1, Abigail Wynne, Michael Duchen
1The Hatter Institute and Centre for Cardiology, University College London, UK.
Circulation
|April 7, 2004
Resumen
La apertura transitoria del poro de transición de permeabilidad mitocondrial (mPTP) y las especies reactivas de oxígeno (ROS) son clave para la cardioprotección del precondicionamiento y el desacoplamiento. La inhibición de mPTP o ROS elimina estos efectos protectores.
Área de la Ciencia:
- Investigación cardiovascular Investigación cardiovascular Investigación cardiovascular Investigación cardiovascular Investigación cardiovascular
- Fisiología mitocondrial Fisiología mitocondrial
- La señalización celular.
Sus antecedentes:
- La apertura transitoria del poro de transición de permeabilidad mitocondrial (mPTP) influye en los niveles de calcio mitocondrial y la señalización de las especies reactivas de oxígeno (ROS).
- Se supone que esta apertura transitorio de mPTP media los efectos protectores observados en el precondicionamiento miocárdico y el desacoplamiento mitocondrial.
Objetivo del estudio:
- Investigar el papel de la apertura de mPTP transitorio y ROS en la mediación de los efectos protectores del precondicionamiento miocárdico y el desacoplamiento mitocondrial.
Principales métodos:
- Los corazones de rata aislados y perfundidos sufrieron lesiones por isquemia/reperfusión.
- La relación riesgo-volumen de infarto se evaluó después de las intervenciones.
- Se utilizaron agentes farmacológicos para inhibir la apertura de mPTP (ciclosporina-A, sanglifehrina-A) o ROS (N-mercaptopropionilglicina) durante los protocolos de precondicionamiento.
- El diazoxido, el CCPA y el 2,4-dinitrofenol se utilizaron para el precondicionamiento farmacológico y el desacoplamiento mitocondrial.
Principales resultados:
- La inhibición de la apertura de mPTP durante el precondicionamiento eliminó los efectos protectores del precondicionamiento isquémico (IPC), el diazóxido, el CCPA y el 2,4-dinitrofenol.
- La inhibición de las ROS eliminó los efectos protectores de IPC, diazóxido y 2,4-dinitrofenol, pero no el CCPA.
- Diazoxide indujo la apertura de mPTP transitorio sensible a la CsA en los miocitos de rata adulta.
Conclusiones:
- Los efectos protectores de IPC, diazóxido y desacoplamiento mitocondrial son dependientes de la transiente apertura de mPTP.
- La señalización de ROS también es crucial para los mecanismos de protección mediados por IPC, diazóxido y desacoplamiento mitocondrial.
Videos de Conceptos Relacionados
01:39Mitochondrial Protein Sorting
4.4K
Mitochondria are double-membrane organelles of the eukaryotes involved in cellular metabolism, signaling, ATP synthesis, and programmed cell death. Each of these processes requires specific proteins and enzymes that must be correctly sorted to the right mitochondrial subcompartment for the proper functioning of the organelle.
Most of these mitochondrial proteins are encoded by the nucleus and imported to the mitochondria as unfolded or loosely folded precursors. Mitochondrial precursors...
Most of these mitochondrial proteins are encoded by the nucleus and imported to the mitochondria as unfolded or loosely folded precursors. Mitochondrial precursors...
4.4K
01:39Mitochondrial Precursor Proteins
2.9K
Mitochondrial precursors are partially unfolded or loosely folded polypeptide chains. Newly synthesized precursors are inhibited from spontaneously folding into their native conformation by the cytosolic chaperones, heat shock proteins 70 (Hsp70), and mitochondrial import stimulation factors (MSFs). Precursors bound to MSFs are guided to the TOM70-TOM37 receptors, while precursors bound to Hsp70 chaperones are targetted to TOM20-TOM22 receptor complexes.
Most of the mitochondrial...
Most of the mitochondrial...
2.9K
01:19Translocation of Proteins into the Mitochondria
8.8K
Mitochondrial precursors are translocated to the internal subcompartments via independent mechanisms involving distinct protein machineries called translocases.
Sorting of outer membrane proteins:
Mitochondrial outer membrane proteins are of two types: the transmembrane, beta-barrel porins, and the membrane-anchored, alpha-helical proteins. Beta-barrel porin precursors are translocated by the TOM complex and inserted into the outer mitochondrial membrane by the SAM complex. In contrast,...
Sorting of outer membrane proteins:
Mitochondrial outer membrane proteins are of two types: the transmembrane, beta-barrel porins, and the membrane-anchored, alpha-helical proteins. Beta-barrel porin precursors are translocated by the TOM complex and inserted into the outer mitochondrial membrane by the SAM complex. In contrast,...
8.8K
01:37Energy to Drive Translocation
2.0K
Mitochondrial protein import is powered by two distinct energy sources: ATP hydrolysis and electrochemical potential across the inner membrane. Newly synthesized precursors are bound by cytosolic chaperones of the Hsp70 family, which guide them to the import receptors on the mitochondrial surface. Utilizing the energy of ATP hydrolysis, Hsp70 chaperones transfer these precursors to the TOM receptors on the mitochondrial outer membrane.
Generally, polypeptides are unfolded by two distinct...
Generally, polypeptides are unfolded by two distinct...
2.0K
01:34Protein Transport into the Inner Mitochondrial Membrane
3.5K
Nuclear encoded mitochondrial precursors are imported to the inner membrane in a multistep process involving two separate translocons, TIM22 and TIM23. TIM23 is a cation-selective pore that remains closed by the N terminal segment of the protein. Negative charges on the TIM23 act as a receptor for the incoming precursor, pulling the positively charged matrix-targeting sequence for peptide insertion and translocation.
Transport of mitochondrial precursors across the TIM23 channel is driven by...
Transport of mitochondrial precursors across the TIM23 channel is driven by...
3.5K
01:21Structure of Porins
3.1K
Mitochondria, chloroplasts, and gram-negative bacteria have transmembrane, beta-barrel proteins called porins to mediate the free diffusion of ions and metabolites across the membrane. Mitochondrial porin precursors contain conserved amino acid sequences called beta signals at their C-terminal. Beta signals have a motif of PoXGXXHyXHy (Po-Polar, X-Any amino acid, G-Glycine, Hy-LargeHydrophobic), which are crucial for precursor recognition to initiate precursor assembly. Beta-barrel...
3.1K