Daptomycin Resistance in Enterococci Is Associated with Distinct Alterations of Cell Membrane Phospholipid Content

The intraerythrocytic development of the malaria parasite is accompanied by distinct morphological and biochemical changes in the host cell membrane, yet little is known about development-related alterations in the transbilayer organization of membrane phospholipids in parasitized cells. This question was examined in human red cells infected with Plasmodium falciparum. Normal red cells were infected with strain FCR3 or with clonal derivatives that either produce (K+) or do not produce (K-) knobby protuberances on the infected red cells. Parasitized cells were harvested at various stages of parasite development, and the bilayer orientation of red cell membrane phospholipids was determined chemically using 2,4,6-trinitrobenzene sulphonic acid (TNBS) or enzymatically using bee venom phospholipase A2 (PLA2) and sphingomyelinase C (SMC). We found that parasite development was accompanied by distinct alterations in the red cell membrane transbilayer distribution of phosphatidylcholine (PC), phosphatidylethanolamine (PE), and phosphatidylserine (PS). Increases in the exoplasmic membrane leaflet exposure of PE and PS were larger in the late-stage parasitized cells than in the early-stage parasitized cells. Similar results were obtained for PE membrane distribution using either chemical (TNBS) or enzymatic (PLA2 plus SMC) methods, although changes in PS distribution were observed only with TNBS. Uninfected cohort cells derived from mixed populations of infected and uninfected cells exhibited normal patterns of membrane phospholipid organization. The observed alterations in P falciparum-infected red cell membrane phospholipid distribution, which is independent of the presence or absence of knobby protuberances, might be associated with the drastic changes in cell membrane permeability and susceptibility to early hemolysis observed in the late stages of parasite development.

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Altered plasma membrane phospholipid organization in Plasmodium falciparum-infected human erythrocytes

Blood ◽

10.1182/blood.v69.2.401.401 ◽

1987 ◽

Vol 69 (2) ◽

pp. 401-407 ◽

Cited By ~ 56

Author(s):

RS Schwartz ◽

JA Olson ◽

C Raventos-Suarez ◽

M Yee ◽

RH Heath ◽

...

Keyword(s):

Plasmodium Falciparum ◽

Cell Membrane ◽

Early Stage ◽

Red Cells ◽

Membrane Phospholipid ◽

Cell Membrane Permeability ◽

Parasite Development ◽

Red Cell ◽

Membrane Phospholipids ◽

Red Cell Membrane

Abstract The intraerythrocytic development of the malaria parasite is accompanied by distinct morphological and biochemical changes in the host cell membrane, yet little is known about development-related alterations in the transbilayer organization of membrane phospholipids in parasitized cells. This question was examined in human red cells infected with Plasmodium falciparum. Normal red cells were infected with strain FCR3 or with clonal derivatives that either produce (K+) or do not produce (K-) knobby protuberances on the infected red cells. Parasitized cells were harvested at various stages of parasite development, and the bilayer orientation of red cell membrane phospholipids was determined chemically using 2,4,6-trinitrobenzene sulphonic acid (TNBS) or enzymatically using bee venom phospholipase A2 (PLA2) and sphingomyelinase C (SMC). We found that parasite development was accompanied by distinct alterations in the red cell membrane transbilayer distribution of phosphatidylcholine (PC), phosphatidylethanolamine (PE), and phosphatidylserine (PS). Increases in the exoplasmic membrane leaflet exposure of PE and PS were larger in the late-stage parasitized cells than in the early-stage parasitized cells. Similar results were obtained for PE membrane distribution using either chemical (TNBS) or enzymatic (PLA2 plus SMC) methods, although changes in PS distribution were observed only with TNBS. Uninfected cohort cells derived from mixed populations of infected and uninfected cells exhibited normal patterns of membrane phospholipid organization. The observed alterations in P falciparum-infected red cell membrane phospholipid distribution, which is independent of the presence or absence of knobby protuberances, might be associated with the drastic changes in cell membrane permeability and susceptibility to early hemolysis observed in the late stages of parasite development.

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Low Levels of Essential Fatty Acids in the Red Blood Cell Membrane Phospholipid Fraction of Long-Term Home Parenteral Nutrition Patients

Journal of Parenteral and Enteral Nutrition ◽

10.1177/0148607196020005377 ◽

1996 ◽

Vol 20 (5) ◽

pp. 377-378 ◽

Cited By ~ 4

Author(s):

Loris Pironi ◽

Andrea Belluzzi ◽

Mario Miglioli

Keyword(s):

Fatty Acids ◽

Cell Membrane ◽

Blood Cell ◽

Parenteral Nutrition ◽

Red Blood Cell ◽

Essential Fatty Acids ◽

Home Parenteral Nutrition ◽

Membrane Phospholipid ◽

Low Levels

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Erythrocyte cell membrane phospholipid levels compared against reported dietary intakes of polyunsaturated fatty acids in pregnant Mexican women

Public Health Nutrition ◽

10.1079/phn2002381 ◽

2002 ◽

Vol 5 (6a) ◽

pp. 931-937 ◽

Cited By ~ 53

Author(s):

Maria-Socorro Parra ◽

Lourdes Schnaas ◽

Mohsen Meydani ◽

Estela Perroni ◽

Sandra Martíanez ◽

...

Keyword(s):

Fatty Acids ◽

Cell Membrane ◽

Polyunsaturated Fatty Acids ◽

Dietary Intake ◽

Pregnant Women ◽

Pearson Correlation ◽

Membrane Phospholipid ◽

Mexican Women ◽

Dietary Intakes ◽

Tuna Fish

AbstractObjective:To evaluate the validity of a food-frequency questionnaire (FFQ) for assessment of the dietary intakes of polyunsaturated fatty acids (PUFAs) against a biochemical marker of fat intake, erythrocyte cell membrane phospholipid levels, during pregnancy.Design:Cross-sectional analysis.Setting:Developmental Neurobiology Department, National Institute of Perinatology, Mexico City.Subjects:One hundred forty-six healthy pregnant women during the last trimester of pregnancy. Among women enrolled, the first 35 pregnant women (24%) had their erythrocytes analysed for fatty acid status.Methods:We administered an FFQ and compared intakes of PUFAs against their erythrocyte cell membrane concentrations, processed by gas chromatography.Results:Pearson correlation coefficients among α-linolenic acid (ALN), docosahexaenoic acid (DHA) and eicosapentaenoic acid in erythrocyte cell membranes against their crude dietary counterparts were 0.32, 0.35 and 0.36 (each P < 0.05). In a simple linear regression, erythrocyte DHA and arachidonic acid (AA) were significantly related to their respective dietary intakes (β = 0.30, 95% confidence interval (CI): 0.007–0.60, P = 0.045 for DHA; β = 0.49, 95% CI: 0.010–0.98, P = 0.044 for AA). Erythrocyte cell membrane ALN concentration (%/total) was only marginally related to ALN dietary intake (mg day−1) (β = 0.52, 95% CI: −0.020–1.10, P = 0.061). However, after adjustment for long-chain n–3 PUFA/AA, this association reached significance (β = 0.44, 95% CI: 0.026–0.825, P = 0.038). Main dietary sources for n–3 PUFAs were canned tuna fish and fresh catfish; for n–6 these were eggs and cow's milk. The use of this FFQ in these pregnant Mexican women provided estimates of average long-term intakes of PUFAs and correlated reasonably well with their erythrocyte cell membrane phospholipid status. However, we need to consider that, during pregnancy, there is a faster turnover of PUFAs from fat storage that may modify the profile of erythrocyte PUFAs and lower the correlation between dietary intake and erythrocyte PUFAs.

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