Chinese hamster ovary (CHO) cell mutants that required exogenously added phosphatidylserine for cell growth were isolated by using the replica technique with polyester cloth, and three such mutants were characterized. Labeling experiments on intact cells with 32Pi and L-[U-14C]serine revealed that a phosphatidylserine auxotroph, designated as PSA-3, was strikingly defective in phosphatidylserin...

Labile blood products contain phosphatidylserine-expressing cell dusts, including apoptotic cells and microparticles. These cell by-products are produced during blood product process or storage and derived from the cells of interest that exert a therapeutic effect (red blood cells or platelets). Alternatively, phosphatidylserine-expressing cell dusts may also derived from contaminating cells, s...

PURPOSE New treatment strategies aimed at damaging tumor vasculature could potentially improve tumor response to radiation therapy. We recently showed that anionic phospholipids, principally phosphatidylserine, are specifically exposed on the luminal surface of tumor blood vessels. Here we tested the hypothesis that radiation therapy can increase phosphatidylserine exposure on lung tumor vascul...

Paraquat is a pneumotoxin that causes lung injury by enhancing oxidative stress; however, the cellular responses to these redox events are undefined. We previously showed that paraquat produced selective peroxidation of phosphatidylserine that preceded apoptosis in 32D cells. We now report that the phospholipase A2(PLA2) inhibitor quinacrine can attenuate phosphatidylserine oxidation and also b...

Phosphatidylserine synthesis by the endoplasmic reticulum fraction isolated from castor bean (Ricinus communis var. Hale) endosperm was assayed by measuring the incorporation of (14)C-l-serine into chloroform-soluble material. Both phosphatidylserine and phosphatidylethanolamine were identified as products. The incorporation required calcium ions and showed an optimum pH of 7.8 in 2 mm CaCl(2)....

A fter being swallowed alive by an immune cell, most pathogens meet a grisly death-by-digestion in the cell’s equivalent of a stomach—the lysosomes. Some sneaky bugs, however, have learned to avoid this fate. They are still swallowed—into membrane pouches called phagosomes—but never make it to the deadly lysosomes. Instead, they carry on living inside other membrane-enclosed compartments within...

Clearance of apoptotic cells is necessary for tissue development, homeostasis and resolution of inflammation. The uptake of apoptotic cells is initiated by an 'eat-me' signal, such as phosphatidylserine, on the cell surface and phagocytes recognize the signal by using specific receptors. In this study, we show that the soluble form of the receptor for advanced glycation end products (RAGE) bind...

Although lysolecithin has been frequently prepared and has been the subject of much research, other lysophosphatides have not been studied in detail. Our interest in nervous tissue led us to use human brain as the starting material from which phosphatidylserine-rich fractions were prepared by the method of Folch (1942). Long & Penny (1957) demonstrated that the phosphatidylserine-containing fra...

A modification of the phospholipase D-catalyzed synthesis of phosphatidylserine is described, which allows the handling of small quantities of lipid without the need for an ether-water system. By using octylglucoside to disperse the lipid during the enzymatic conversion, it was possible to reduce the volume of the reaction mixture to 50-100 microliters. The amount of lipid that can be handled i...