Tafazzin modulates cellular phospholipid composition to regulate AML stemness

ABSTRACT Chlamydia trachomatis is an obligate intracellular eubacterial parasite capable of infecting a wide range of eucaryotic host cells. Purified chlamydiae contain several lipids typically found in eucaryotes, and it has been established that eucaryotic lipids are transported from the host cell to the parasite. In this report, we examine the phospholipid composition of C. trachomatispurified from host cells grown under a variety of conditions in which the cellular phospholipid composition was altered. A mutant CHO cell line, with a thermolabile CDP-choline synthetase, was used to show that decreased host cell phosphatidylcholine levels had no significant effect on C. trachomatis growth. However, less phosphatidylcholine was transported to the parasite and purified elementary bodies contained decreased levels of phosphatidylcholine. Brefeldin A, fumonisin B1, and exogenous sphingomyelinase were used to alter levels of host cell sphingomyelin. None of the agents had a significant effect on C. trachomatisreplication. Treatment with fumonisin B1 and exogenous sphingomyelinase resulted in decreased levels of host cell sphingomyelin. This had no effect on glycerophospholipid trafficking to chlamydiae; however, sphingomyelin trafficking was reduced and elementary bodies purified from treated cells had reduced sphingomyelin content. Exposure to brefeldin A, which had no adverse effect on chlamydia growth, resulted in an increase in cellular levels of sphingomyelin and a concomitant increase in the amount of sphingomyelin in purified chlamydiae. Under the experimental conditions used, brefeldin A treatment had only a small effect on sphingomyelin trafficking to the host cell surface or to C. trachomatis. Thus, the final phospholipid composition of purified C. trachomatis mimics that of the host cell in which it is grown.

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Correlation of Cellular Phospholipid Content with Nisin Resistance of Listeria monocytogenes Scott A

Journal of Food Protection ◽

10.4315/0362-028x-58.4.416 ◽

1995 ◽

Vol 58 (4) ◽

pp. 416-420 ◽

Cited By ~ 68

Author(s):

XINTIAN MING ◽

MARK A. DAESCHEL

Keyword(s):

Listeria Monocytogenes ◽

Parental Strain ◽

Phospholipid Composition ◽

Resistant Mutant ◽

Structure And Function ◽

Phospholipid Content ◽

Membrane Structure And Function ◽

And Function ◽

Cellular Phospholipid ◽

Resistant Cells

A nisin-resistant mutant of Listeria monocytogenes Scott A has been characterized by comparing its phospholipid composition with the nisin-sensitive parental strain. The total phospholipids of resistant cells were significantly (P < 0.001) decreased compared to the parental strain. The types of phospholipids isolated from nisin-resistant and sensitive cells were identical, but there was a significant decrease (P < 0.01) in the amount of three individual phospholipids. Nisin-resistant cells were found to bind less nisin and release less phospholipids than sensitive cells when treated with same concentrations of nisin. The cell surface of resistant cells was less hydrophobic compared to sensitive cells, which also may have contributed to the observed nisin resistance. The results suggest that fundamental changes occurred in the membrane structure and function of the resistant mutant as a response to nisin.

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Platelet Functions in Relation to Dietary Fats in Farmers from two Regions of France

Thrombosis and Haemostasis ◽

10.1055/s-0038-1648685 ◽

1978 ◽

Vol 40 (02) ◽

pp. 518-531 ◽

Cited By ~ 24

Author(s):

S Renaud ◽

E Dumont ◽

F Godsey ◽

A Suplisson ◽

C Thevenon

Keyword(s):

Platelet Aggregation ◽

Platelet Rich Plasma ◽

Plasma Cholesterol ◽

Phospholipid Composition ◽

Saturated Fat ◽

Phosphatidyl Inositol ◽

Phosphatidyl Serine ◽

Dietary Fats ◽

Platelet Phospholipid ◽

Platelet Functions

SummaryTo determine whether the long-term feeding of dietary fats affect platelet functions in man, platelet aggregation (to thrombin ADP, collagen, epinephrine) and clotting activity of platelet-rich plasma (PRP), platelet-poor plasma and of washed platelets, were studied in a mobile-laboratory in 44 healthy male farmers (40-45 years) from two French regions Var and Moselle, in relation to lipemia, glycemia, dietary nutriments, and platelet phospholipid composition. In the Moselle subjects, the platelet clotting activity of PRP and of washed platelets, the platelet aggregation to thrombin and ADP, were highly significantly (p <0.001) increased as compared to those of Var, but not the plasma cholesterol, which was identical in the two regions.In Moselle, the intake of total calories, total lipids and saturated fats was higher than in the Var.However, it was only with the saturated fat intake (mostly stearic acid) that the platelet clotting activity (p <0.01) and the platelet aggregation (p <0.001) were highly significantly correlated. The platelet clotting activity was also significantly (p <0.001) correlated with the fatty acid composition of the platelet phospholipid fractions phosphatidyl serine + phosphatidyl inositol.

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