Phospholipid asymmetry in the plasma membrane of malaria infected erythrocytes

1990 ◽  
Vol 68 (2) ◽  
pp. 579-585 ◽  
Author(s):  
G. N. Moll ◽  
H. J. Vial ◽  
E. M. Bevers ◽  
M. L. Ancelin ◽  
B. Roelofsen ◽  
...  
Keyword(s):  
Plasma Membrane ◽  
Plasmodium Knowlesi ◽  
Phospholipase A ◽  
Red Cell ◽  
Red Cell Membrane ◽  
Exterior Surface ◽  
Phospholipid Asymmetry ◽  
Pancreatic Phospholipase ◽  
Hydrolysis Of ◽  
Excellent Tool

The transbilayer distribution of glycerophospholipids in the plasma membrane of Plasmodium knowlesi infected erythrocytes was studied by using lysine-116-ε-N-palmitoyl amidinated pancreatic phospholipase A2. As a consequence of its superior membrane penetrating capacities, this modified enzyme rapidly degrades its substrates in the outer membrane leaflet of intact erythrocytes, a property that makes the enzyme an excellent tool to study the malaria parasitized red cell. The modified phospholipase A2 caused a nonlytic hydrolysis of up to 12–15% of the phosphatidylethanolamine and none of the phosphatidylserine in the red cell membrane, irrespective of whether the cells harboured trophozoite and schizont stages of parasites or no parasites at all. The absence of phosphatidylserine at the exterior surface of Plasmodium infected erythrocytes was confirmed by applying the prothrombinase assay on Plasmodium falciparum infected human erythrocytes. Consequently, the results from these and previous studies indicate that the plasma membrane of Plasmodium infected erythrocytes exhibit a normal transbilayer phospholipid asymmetry.Key words: malaria, plasma membrane, phospholipid asymmetry, erythrocyte, prothrombinase assay.

Lamellar membranes associated with rhoptries in erythrocytic merozoites of Plasmodium knowlesi: a clue to the mechanism of invasion

Parasitology ◽  
1986 ◽  
Vol 92 (2) ◽  
pp. 291-303 ◽  
Author(s):  
L. H. Bannister ◽  
G. H. Mitchell ◽  
G. A. Butcher ◽  
E. D. Dennis
Keyword(s):  
Cell Membrane ◽  
Late Stage ◽  
Plasmodium Knowlesi ◽  
Parasitophorous Vacuole ◽  
Lipid Extraction ◽  
Red Cells ◽  
Red Cell ◽  
Red Cell Membrane

SUMMARYIn merozoites of Plasmodium knowlesi, rhoptries have a dense substructure of fine (2·5 nm diameter) granules and short rods. These are not altered by lipid extraction, and stain with ethanolic phosphotungstate indicating a proteinaceous composition. Various types of fixation also show multilamellar whorls with a periodicity of 5–7 rim in the tips of rhoptries or extruded at the merozoite apex. In merozoites fixed during invasions of red cells, membrane continuity typically occurs between the rim of the rhoptry canal and the red cell membrane, but where this contact has apparently been lost, extensive membranous whorls and blebs are often found at the apex of the parasite. Similar structures occur at the spices of merozoites within late-stage schizonts. It is suggested that the same mechanism which generates these lamellae forms the parasitophorous vacuole by inserting membranous elements formed by the parasite into the red cell membrane, so causing its invagination. A similar mechanism may be responsible for the release of merozoites from the late-stage schizont.

scholarly journals Increased Erythrocyte Phosphatidylserine Exposure in Chronic Renal Failure

1999 ◽  
Vol 10 (9) ◽  
pp. 1982-1990
Author(s):  
MARIO BONOMINI ◽  
VITTORIO SIROLLI ◽  
NICOLA SETTEFRATI ◽  
SECONDO DOTTORI ◽  
LORENZO DI LIBERATO ◽  
...  
Keyword(s):  
Renal Failure ◽  
Chronic Renal Failure ◽  
Cell Function ◽  
Red Cell ◽  
Creatinine Concentration ◽  
Red Cell Membrane ◽  
Phospholipid Asymmetry ◽  
Outer Leaflet ◽  
Phosphatidylserine Exposure

Abstract. The appearance of phosphatidylserine, an aminophospholipid normally confined to the inner monolayer, at the outer leaflet of red cell membrane may have several pathophysiologic implications. This study examines erythrocyte phosphatidylserine exposure in chronic renal failure (CRF) patients on conservative treatment or on dialysis, to assess possible alterations to phospholipid asymmetry in a condition associated with a state of deranged red cell function. A significant increase in phosphatidylserine-expressing erythrocytes was found in undialyzed patients with CRF (2.32%) and patients on hemodialysis (3.06%) and on peritoneal dialysis (2.14%) compared with control subjects (0.68%). In undialyzed CRF patients, a strong correlation (r = 0.903) was found between the percentage of phosphatidylserine-expressing red cells and the serum creatinine concentration. The increased exposure of phosphatidylserine in uremic erythrocytes may be due to inhibition of phosphatidylserine transport from the outer to the inner leaflet of plasma membrane and may promote an increased erythrophagocytosis. In reconstitution experiments, normal erythrocytes showed an increase in phosphatidylserine-expressing cells when incubated in uremic plasma (3.2% after 2 h versus 1.1% at beginning of incubation), whereas phosphatidylserine-positive uremic erythrocytes decreased when resuspended in normal plasma (2.03% after 2 h and 1.65% after 8 h versus 2.9% at beginning of incubation). Preliminary characterization of the putative uremic compound(s) indicates a molecular weight between 10,000 and 20,000, as well as heat instability. These findings show an impairment of erythrocyte membrane phospholipid asymmetry in CRF patients, regardless of the dialysis treatment. Such abnormality seems related to the uremic state and could contribute to the red cell pathology present in CRF.

A High-Angle X-ray Diffraction Study of Red Cell Membranes after Treatment with Phospholipases A2 and C

1972 ◽  
Vol 50 (12) ◽  
pp. 1260-1266 ◽  
Author(s):  
J. C. Bernengo ◽  
H. Simpkins
Keyword(s):  
Structural Change ◽  
Phospholipase C ◽  
Cell Membranes ◽  
Phospholipase A ◽  
Red Cell ◽  
High Angle ◽  
X Ray Diffraction ◽  
Red Cell Membrane ◽  
X Ray ◽  
Phospholipases A2

Comparison of the high-angle X-ray diffraction patterns of hydrated red blood cell membranes after methanol, phospholipase A2, and phospholipase C treatment results in a more detailed understanding of the diffraction pattern obtained from untreated membranes. This study also presents more information as to the fate of the lipid and protein region of the membrane after the different phospholipase treatments. It reinforces the concept that phospholipase A2 treatment produces a structural change in the protein regions of the red cell membrane and that a structural change occurs in the lipid regions after phospholipase C treatment which may allow some of the cholesterol in the membrane to form crystallites.

scholarly journals Detection of altered membrane phospholipid asymmetry in subpopulations of human red blood cells using fluorescently labeled annexin V

Blood ◽  
1996 ◽  
Vol 87 (3) ◽  
pp. 1179-1187 ◽  
Author(s):  
FA Kuypers ◽  
RA Lewis ◽  
M Hua ◽  
MA Schott ◽  
D Discher ◽  
...  
Keyword(s):  
Sickle Cell ◽  
Sickle Cell Anemia ◽  
Magnetic Beads ◽  
Fluorescent Microscopy ◽  
Annexin V ◽  
Fluorescein Isothiocyanate ◽  
Red Cells ◽  
Red Cell ◽  
Red Cell Membrane ◽  
Phospholipid Asymmetry

The phospholipids of the human red cell are distributed asymmetrically in the bilayer of the red cell membrane. In certain pathologic states, such as sickle cell anemia, phospholipid asymmetry is altered. Although several methods can be used to measure phospholipid organization, small organizational changes have been very difficult to assess. Moreover, these methods fail to identify subpopulations of cells that have lost their normal phospholipid asymmetry. Using fluorescently labeled annexin V in flow cytometry and fluorescent microscopy, we were able to identify and quantify red cells that had lost their phospholipid asymmetry in populations as small as 1 million cells. Moreover, loss of phospholipid organization in subpopulations as small as 0.1% of the total population could be identified, and individual cells could be studied by fluorescent microscopy. An excellent correlation was found between fluorescence-activated cell sorter (FACS) analysis results using annexin V to detect red cells with phosphatidylserine (PS) on their surface and a PS-requiring prothrombinase assay using similar red cells. Cells that bound fluorescein isothiocyanate (FITC)-labeled annexin V could be isolated from the population using magnetic beads covered with an anti-FITC antibody. Evaluation of blood samples from patients with sickle cell anemia under oxygenated conditions demonstrated the presence of subpopulations of cells that had lost phospholipid asymmetry. While only a few red cells were labeled in normal control samples (0.21% +/- 0.12%, n = 8), significantly increased (P < .001) annexin V labeling was observed in samples from patients with sickle cell anemia (2.18% +/- 1.21%, n = 13). We conclude that loss of phospholipid asymmetry may occur in small subpopulations of red cells and that fluorescently labeled annexin V can be used to quantify and isolate these cells.

Intraduodenal Infusion of Lysophosphatidylcholine Restores the Intestinal Absorption of Vitamins a and E in Rats Fed a Low-Zinc Diet

2001 ◽  
Vol 226 (4) ◽  
pp. 342-348 ◽  
Author(s):  
Sang K. Noh ◽  
Sung I. Koo
Keyword(s):  
Oleic Acid ◽  
Intestinal Absorption ◽  
Lipid Emulsion ◽  
The Other ◽  
Phospholipase A ◽  
Intraduodenal Infusion ◽  
Acid Absorption ◽  
Pancreatic Phospholipase ◽  
Fat Soluble Vitamins ◽  
Hydrolysis Of

Our previous work has shown that the lymphatic absorptions of lipids and lipid-soluble vitamins, retinol and α-tocopherol (αTP), are lowered markedly in rats fed a low-zinc (LZ) diet in parallel with lower lymphatic phospholipid outputs. Phosphatidylcholine (PC), when infused enterally, restored the absorptions of fat and retinol, but further lowered the absorption of αTP in rats fed the LZ diet. This study was conducted to determine whether a luminal infusion of lysophosphatidylcholine, a product of PC hydrolysis by pancreatic phospholipase A2 (PLA2), would simultaneously restore the absorptions of retinol and αTP in LZ rats. Rats were trained to consume two meals per day and were divided into two groups. One group was fed an AIN-93G diet containing a LZ (3.0 mg Zn/kg), and the other was fed the same diet, but containing adequate zinc (AZ; 30.0 mg Zn/kg) for 6 weeks. Rats with lymph cannula were infused at 3.0 ml/hr for 8 hr with a lipid emulsion containing retinol, αTP, and 14C-labeled triolein (14C-oleic acid) with or without 1-oleoyl-2-hydroxy phosphatidyicholine (lysoPC) in 24 ml of PBS (pH 6.5). When the lipid emulsion without lysoPC was infused, the absorptions of retinol and αTP were significantly lower in LZ rats (retinol, 13.2 ± 1.5 nmol; αTP, 430.6 ± 66.8 nmol) than in AZ rats (retinol, 18.2 ± 1.0 nmol; αTP, 543.8 ± 58.9 nmol). The lower absorptions of the vitamins in LZ rats occurred in parallel with a significant decrease in 14C-oleic acid absorption. When the emulsion containing lysoPC was infused, however, absorptions of the vitamins (retinol, 18.4 ± 3.0 nmol; αTP, 777.2 ± 92.1 nmol) in LZ rats were restored completely to the control levels (retinol, 20.4 ± 2.8 nmol; αTP, 756.3 ± 136.1 nmol). The results suggest that the luminal hydrolysis of PC to lysoPC by PLA2 may be impaired in LZ rats, resulting in impaired absorption of fat and the fat-soluble vitamins.

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