Permeabilized human leukemia HL-60 and U-937 cells suspended in an acidic or alkaline medium release various unsaturated fatty acids, most abundantly oleic and arachidonic acids. Concomitant production of lysophospholipids suggests that phospholipases A2 play a major role in this fatty acid release reaction. The fatty acid release at acidic conditions depends on the intracellular Ca2+ concentra...

To date, 12 secreted phospholipases A2 (sPLA2s) have been identified in the mouse species and divided into three structural collections (I/II/V/X, III, and XII). On the basis of their different molecular properties and tissue distributions, each sPLA2 is likely to exert distinct functions by acting as an enzyme or ligand for specific soluble proteins or receptors, among which the M-type recepto...

Fourteen kilodalton phospholipase A(2) molecules (PLA(2)) are classified into two groups, I- and II-PLA(2), and only the latter has been considered to play a pathogenetic role in various forms of tissue inflammation. Previously we demonstrated high PLA(2) activity in gingival crevicular fluid (GCF) of patients with periodontal disease, without determining the group of the enzyme involved. In th...

Mutacin II is an antibiotic that is produced by group II Streptococcus mutans. It inhibits the growth of other streptococci as well as many other gram-positive microorganisms by a hitherto unknown mechanism. Mutacin II possess bactericidal activity against susceptible cells. It transiently depolarizes the transmembrane electrical potential (delta psi) and the transmembrane pH gradient (delta pH...

Three key lipid types, cholesterol, ceramides (CER), and free fatty acids (FA), form the stratum corneum (SC) lamellar bilayers that mediate barrier function. Prior studies have shown that barrier requirements regulate CER generation from glucosylCER, and that this catabolic step takes place within the SC interstices. Here, we addressed whether extracellular processing of phospholipids (PL), th...

Within the phospholipase A2 (PLA2) superfamily that hydrolyzes phospholipids to yield fatty acids and lysophospholipids, the secreted PLA2 (sPLA2) enzymes comprise the largest family that contains 11 isoforms in mammals. Individual sPLA2s exhibit unique distributions and specific enzymatic properties, suggesting their distinct biological roles. While sPLA2s have long been implicated in inflamma...

Calcium dependent phospholipase A2 activity in the mixed micelles of 1-palmitoyl-2-oleoyl-phosphatidylglycerol and cholate was measured in sera of 39 patients with Crohn's disease, 40 patients with ulcerative colitis, and 40 healthy controls. The phospholipase A2 activity was significantly raised in those sera of the patients with active Crohn's disease and those with moderate and severe ulcera...