Oxidation of liposomal cholesterol and its effect on phospholipid peroxidation

Schnitzer, Edit; Pinchuk, Ilya; Bor, A.; Leikin-Frenkel, Alicia; Lichtenberg, Dov

doi:10.1016/j.chemphyslip.2006.12.003

Cited by 34 publications

(19 citation statements)

References 39 publications

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“…We found that the leakage of the membrane’s electric potential was the slowest, compared to the other unsaturated phosphatidylcholines which were used. Schnitzer et al (38) have indicated that peroxidation of liposomes containing cholesterol is much slower then peroxidation of liposomes containing palmitoyl-linoleoyl-phosphatidylcholine (PLPC) (16:0–18:2), and our results are compatible with their observation.…”

Section: Resultssupporting

confidence: 93%

Lipid Composition Affects the Rate of Photosensitized Dissipation of Cross-Membrane Diffusion Potential on Liposomes

et al. 2010

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Hydrophobic or amphiphilic tetrapyrrole sensitizers are taken up by cells and are usually located in cellular lipid membranes. Singlet oxygen is photogenerated by the sensitizer and it diffuses in the membrane and causes oxidative damage to membrane components. This damage can occur to membrane lipids and to membrane-localized proteins. Depolarization of the Nernst electric potential on cells' membranes has been observed in cellular photosensitization, but it was not established whether lipid oxidation is a relevant factor leading to abolishing the resting potential of cells' membranes and to their death. In this work we studied the effect of liposomes' lipid composition on the kinetics of hematoporphyrin-photosensitized dissipation of K + -diffusion electric potential that was generated across the membranes. We employed an electrochromic voltage-sensitive spectroscopic probe that possesses a high fluorescence signal response to the potential. We found a correlation between the structure and unsaturation of lipids and the leakage of the membrane, following photosensitization. As the extent of non-conjugated unsaturation of the lipids is increased from 1 to 6 double bonds, the kinetics of depolarization become faster. We also found that the kinetics of depolarization is affected by the percentage of the unsaturated lipids in the liposome: as the fraction of the unsaturated lipids increases the leakage trough the membrane is enhanced. When liposomes are composed of a lipid mixture similar to that of natural membranes and photosensitization is being carried out under usual photodynamic therapy (PDT) conditions, photodamage to the lipids is not likely to cause enhanced permeability of ions through the membrane, which would have been a mechanism that leads to cell death.

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Section: Resultssupporting

confidence: 93%

Lipid Composition Affects the Rate of Photosensitized Dissipation of Cross-Membrane Diffusion Potential on Liposomes

et al. 2010

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“…We can justify this approximation, since peroxidation of cholesterol is much slower than peroxidation of unsaturated phospholipids. 67 This enables us to safely assume that a large fraction of the phospholipids is oxidized during plasma treatment, without significantly affecting the structure of cholesterol. Moreover, the oxidation products of cholesterol still contain rigid ring structures, so we can expect that even upon oxidation, the effect on the structure of the bilayer would be limited.…”

Section: Resultsmentioning

confidence: 99%

Effect of lipid peroxidation on membrane permeability of cancer and normal cells subjected to oxidative stress

et al. 2016

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“…27 We deliberately did not include cholesterol, one of the major components of biomembranes, to our lipid system as our rationale for keeping our lipid system as simple as possible is to allow us to reasonably get at the mechanism of intermolecular interactions of lipids with polymers. Because cholesterol can potentially affect both the process of lipid peroxidation 28 and membrane structure and properties 29 , its effect on polymer-membrane interactions is complicated and will be discussed in a separated report.…”

Section: Resultsmentioning

confidence: 99%

Nature of Interactions between PEO-PPO-PEO Triblock Copolymers and Lipid Membranes: (I) Effect of Polymer Hydrophobicity on Its Ability to Protect Liposomes from Peroxidation

2012

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PEO-PPO-PEO triblock copolymers have opposing effects on lipid membrane integrity: they can behave either as membrane sealants or as membrane permeabilizers. To gain insights into their biomembrane activities, the fundamental interactions between a series of PEO-based polymers and phospholipid vesicles were investigated. Specifically, the effect of copolymer hydrophobicity on its ability to prevent liposomes from peroxidation was evaluated, and partitioning free energy and coefficient involved in the interactions were derived. Our results show that the high degree of hydrophilicity is a key feature of the copolymers that can effectively protect liposomes from peroxidation and the protective effect of the copolymers stems from their adsorption at the membrane surface without penetrating into the bilayer core. The origin of this protective effect induced by polymer absorption is attributed to the retardation of membrane hydration dynamics, which is further illustrated in the accompanying study on dynamic nuclear polarization (DNP)-derived hydration dynamics (Cheng, C.-Y.; Wang, J.-Y.; Kausik, R.; Lee, K. Y. C.; Han S. Biomacromolecules, 2012, DOI: 10.1021/bm300848c).

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Oxidation of liposomal cholesterol and its effect on phospholipid peroxidation

Cited by 34 publications

References 39 publications

Lipid Composition Affects the Rate of Photosensitized Dissipation of Cross-Membrane Diffusion Potential on Liposomes

Lipid Composition Affects the Rate of Photosensitized Dissipation of Cross-Membrane Diffusion Potential on Liposomes

Effect of lipid peroxidation on membrane permeability of cancer and normal cells subjected to oxidative stress

Nature of Interactions between PEO-PPO-PEO Triblock Copolymers and Lipid Membranes: (I) Effect of Polymer Hydrophobicity on Its Ability to Protect Liposomes from Peroxidation

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