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Abstract

BackgoundPrevious studies have shown that the functional capacity of T cells may be modulated by the composition of fatty acids within, and the release of fatty acids from membrane phospholipids, particulary containing arachidonic acid (AA). The remodeling of AA within membrane phospholipids of resting and proliferating CD4+ and CD8+ T cells is examined in this study.ResultsSplenic T cells were cultured in the presence or absence of anti-CD3 mAb for 48 h then labeled with [3H]AA for 20 min. In unstimulated cells, labeled AA was preferentially incorporated into the phosphoglycerides, phosphatidylcholine (PC) followed by phosphatidylinositol (PI) and phosphatidylethanolamine (PE). During a subsequent chase in unlabeled medium unstimulated CD4+ and CD8+ T cells demonstrated a significant and highly selective transfer of free, labeled AA into the PC pool. In contrast, proliferating CD4+ and CD8+ T cells distributed labeled [3H]AA predominantly into PI followed by PC and PE. Following a chase in AA-free medium, a decline in the content of [3H]AA-PC was observed in association with a comparable increase in [3H]AA-PE. Subsequent studies revealed that the cold AA content of all PE species was increased in proliferating T cells compared with that in non-cycling cells, but that enrichment in AA was observed only in the ether lipid fractions. Finally, proliferating T cells preincubated with [3H]AA exhibited a significant loss of labeled arachidonate in the PC fraction and an equivalent gain in labeled AA in 1-alk-1'-enyl-2-arachidonoyl-PE during a chase in unlabeled medium.ConclusionThis apparent unidirectional transfer of AA from PC to ether-containing PE suggests the existence of a CoA-independent transacylase system in T cells and supports the hypothesis that arachidonoyl phospholipid remodeling may play a role in the regulation of cellular proliferation.

Lipoprotein (a) and cardiovascular risk factors in children and adolescents

“…In the study by Guardamagna et al ( 7 ) , patients with family history of three or more cardiovascular events were more likely to have high Lp(a) levels, regardless of other lipid fractions. This fact could be observed in two other studies, Sáez de Lafuente et al ( 8 ) and Obisesan et al ( 10 ) , in which the family history was significantly associated with elevated Lp(a) levels. These results indicate the need for pediatricians and cardiologists' attention in order to identify and early intervene in the risk factors in children and adolescents with proven family history for CVD.…”

“…In the study by Obisesan et al ( 10 ) , high Lp(a) levels were observed in black individuals. They have higher levels compared to other populations and the distribution is less distorted than in white individuals.…”

“…A positive correlation was observed between Lp(a) and LDL cholesterol (LDL-c) (3,8,9), Lp(a) and total cholesterol (TC) ( 9 , 10 ) and Lp(a) and apolipoprotein B (Apo B) ( 3 , 9 ) , which suggests an association between Lp(a) levels and lipid profile. According to Meabe et al ( 3 ) , the fact that high Lp(a) levels are associated with high LDL-c levels proposes that the LDL metabolism may be involved in the Lp(a) synthesis.…”

“…No estudo realizado por Guardamagna et al ( 7 ) , os pacientes com histórico familiar de três ou mais eventos cardiovasculares tinham maior probabilidade de apresentar altos níveis de Lp(a), independentemente das outras frações lipídicas. Esse fato pôde ser observado em outros dois estudos, conduzidos por Sáez de Lafuente et al ( 8 ) e Obisesan et al ( 10 ) , nos quais o histórico familiar esteve significativamente associado a níveis elevados de Lp(a). Esses resultados apontam para a necessidade de atenção especial por parte de pediatras e cardiologistas quanto à identificação e à intervenção precoce nos fatores de risco presentes em crianças e adolescentes com histórico familiar comprovado de DCV.…”

Effect of fish oil omega-3 fatty acids on reduction of depressive symptoms among HIV-seropositive pregnant women: a randomized, double-blind controlled trial

“…These variations could be attributed to differences in the ratio of omega-3 long-chain fatty acids of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), depression assessment tools, intervention duration or physiological status of study participants, which varies by study. Although omega-3 DHA is recognized as an essential structural component of the cell membranes in the central nervous system [29], some evidence suggest that omega-3 EPA may be more beneficial in reduction of depression than DHA, based on its anti-inflammatory effects of the metabolic products of eicosanoids and its oxidized derivatives as well as its efficacy at reducing the inflammatory cytokines [30, 31]. These metabolic products of EPA are important in controlling the cellular inflammation in the CNS that may manifest as depressive symptoms.…”