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An Improved Method to Isolate Mitochondrial Contact Sites
Published on: June 16, 2023
Impairment of mitochondrial function by minocycline
Kathleen Kupsch1, Silvia Hertel, Peter Kreutzmann
1Institute of Biochemistry and Cell Biology, Otto-von-Guericke University Magdeburg, Magdeburg, Germany. kkupsch@web.de
The FEBS Journal
|February 27, 2009
Summary
Minocycline (MC) impairs mitochondrial function by permeabilizing the inner mitochondrial membrane and affecting energy production. This antibiotic
Area of Science:
- Biochemistry
- Cell Biology
- Pharmacology
Background:
- Minocycline (MC) is a tetracycline-like antibiotic with debated effects on mitochondrial function.
- Mitochondria-mediated apoptosis is a critical cellular process influenced by various compounds.
- Understanding MC's impact on mitochondria is crucial for evaluating its therapeutic potential.
Purpose of the Study:
- To investigate the effects of minocycline (MC) on isolated rat liver mitochondria (RLM).
- To determine how incubation medium composition influences MC's effects on RLM.
- To elucidate the mechanisms underlying MC-induced mitochondrial dysfunction.
Main Methods:
- Incubation of isolated rat liver mitochondria (RLM) in KCl-based and sucrose-based media.
- Assessment of mitochondrial swelling, cytochrome c release, and membrane potential.
- Measurement of respiration (state 3 and uncoupled) and calcium retention capacity.
- Use of specific inhibitors (N,N'-dicyclohexylcarbodiimide, tributyltin) to probe ion transport.
Main Results:
- Minocycline (MC) induced mitochondrial swelling and cytochrome c release in KCl-based medium, but not in sucrose-based medium.
- MC impaired mitochondrial depolarization, state 3, and uncoupled respiration in KCl-based medium.
- MC abolished the Ca(2+) retention capacity of RLM, suggesting permeability transition induction.
- MC caused rapid depletion of endogenous Mg(2+) from RLM, potentially activating ion channels.
Conclusions:
- The incubation medium significantly modulates minocycline's (MC) effects on mitochondria.
- MC permeabilizes the inner mitochondrial membrane to ions (K+, Cl-) in a KCl-dependent manner.
- MC impairs energy-dependent mitochondrial functions and calcium homeostasis at low micromolar concentrations.
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