Related Experiment Video

Updated: Aug 26, 2026

Assessment of Open Probability of the Mitochondrial Permeability Transition Pore in the Setting of Coenzyme Q Excess
07:35

Assessment of Open Probability of the Mitochondrial Permeability Transition Pore in the Setting of Coenzyme Q Excess

Published on: June 1, 2022

Mitochondrial permeability transition induced by reactive oxygen species is independent of cholesterol-regulated

Anna Colell1, Carmen García-Ruiz, Montserrat Mari

  • 1Institut de Malalties Digestives, Hospital Clínic y Provincial, Instituto Investigaciones Biomédicas August Pi Suñer, C/Villarroel 170, 08036 Barcelona, Spain.

FEBS Letters
|February 28, 2004
PubMed

Insights

Cholesterol enrichment impairs mitochondrial permeability transition (MPT) induced by atractyloside but not reactive oxygen species (ROS). ROS trigger MPT and apoptosis even in cholesterol-enriched mitochondria, indicating ROS-induced MPT is independent of membrane fluidity.

Area of Science:

  • Mitochondrial biology
  • Cellular signaling
  • Biochemistry

Background:

  • Cholesterol enrichment of rat liver mitochondria (CHM) decreases membrane fluidity.
  • This reduced fluidity impairs atractyloside-induced mitochondrial permeability transition (MPT).

Purpose of the Study:

  • To investigate the effect of cholesterol enrichment on MPT induced by reactive oxygen species (ROS).

Main Methods:

  • Induction of MPT using superoxide anion (xanthine/xanthine oxidase) and hydrogen peroxide (ganglioside GD3/GSH depletion).
  • Assessment of mitochondrial swelling and release of apoptotic factors (cytochrome c, Smac/Diablo, apoptosis-inducing factor).
  • Inhibition studies using butylated hydroxytoluene, anti-VDAC antibody, and cyclosporin A.

Main Results:

  • Superoxide anion triggered mitochondrial swelling and cytochrome c release in CHM, inhibited by antioxidants, anti-VDAC antibody, and cyclosporin A.
  • Hydrogen peroxide induced mitochondrial swelling and release of multiple apoptotic factors in both control and CHM.
  • ROS-induced MPT and apoptosome activation occurred irrespective of cholesterol-induced changes in mitochondrial membrane dynamics.

Conclusions:

  • Reactive oxygen species (ROS) induce MPT and subsequent apoptosis signaling pathways.
  • ROS-induced MPT is independent of mitochondrial membrane fluidity alterations caused by cholesterol enrichment.

More Related Videos

Multi-parameter Measurement of the Permeability Transition Pore Opening in Isolated Mouse Heart Mitochondria13:42

Multi-parameter Measurement of the Permeability Transition Pore Opening in Isolated Mouse Heart Mitochondria

Published on: September 7, 2012

Measuring Mitochondrial Substrate Flux in Recombinant Perfringolysin O-Permeabilized Cells06:17

Measuring Mitochondrial Substrate Flux in Recombinant Perfringolysin O-Permeabilized Cells

Published on: August 13, 2021

Related Concept Videos

Mitochondrial Membranes01:45

Mitochondrial Membranes

A single mitochondrion is a bean-shaped organelle enclosed by a double-membrane system. The outer membrane of mitochondria is smooth and contains many porins - the integral membrane transporters. Porins enable free diffusion of ions and small uncharged molecules through the outer mitochondrial membrane but limit the transport of molecules larger than 5000 Daltons. Further, the outer mitochondrial membrane forms a unique structure called membrane contact sites with other subcellular organelles,...
Mitochondrial Membranes01:45

Mitochondrial Membranes

A single mitochondrion is a bean-shaped organelle enclosed by a double-membrane system. The outer membrane of mitochondria is smooth and contains many porins - the integral membrane transporters. Porins enable free diffusion of ions and small uncharged molecules through the outer mitochondrial membrane but limit the transport of molecules larger than 5000 Daltons. Further, the outer mitochondrial membrane forms a unique structure called membrane contact sites with other subcellular organelles,...
The Inner Mitochondrial Membrane01:28

The Inner Mitochondrial Membrane

The inner mitochondrial membrane is the primary site of ATP synthesis. The inner membrane domain that forms a smooth layer adjacent to the outer membrane is called the inner boundary membrane. This domain contains membrane transporters that drive metabolites in and out of the mitochondria.  In contrast, the inner membrane network that invaginates into the matrix space is called the cristae membrane. This domain accounts for principle mitochondrial function as it accommodates the protein...
Translocation of Proteins into the Mitochondria01:19

Translocation of Proteins into the Mitochondria

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,...
Membrane Fluidity01:26

Membrane Fluidity

Membrane fluidity is explained by the fluid mosaic model of the cell membrane, which describes the plasma membrane structure as a mosaic of components—including phospholipids, cholesterol, proteins, and carbohydrates—that gives the membrane a fluid character.
Mosaic nature of the membrane
The mosaic characteristic of the membrane helps the plasma membrane remain fluid. The integral proteins and lipids exist as separate but loosely-attached molecules in the membrane. The membrane is a relatively...
Membrane Fluidity01:23

Membrane Fluidity

Cell membranes are composed of phospholipids, proteins, and carbohydrates loosely attached to one another through chemical interactions. Molecules are generally able to move about in the plane of the membrane, giving the membrane its flexible nature called fluidity. Two other features of the membrane contribute to membrane fluidity: the chemical structure of the phospholipids and the presence of cholesterol in the membrane.Fatty acids tails of phospholipids can be either saturated or...