Apoptosis in human primary brain tumours: actions of arachidonic acid

Williams, J. Raymond; Leaver, H.A.; Ironside, James W.; Miller, Eric P.; Whittle, Ian R.; Gregor, A.

doi:10.1016/s0952-3278(98)90113-2

Cited by 51 publications

(38 citation statements)

References 17 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In addition, FFAs, especially saturated fatty acids, are known to mediate apoptosis in pancreatic cells, hepatocytes, human granuloma cells and brain tumors (Shimabukuro et al 1998, Williams et al 1998, Wu & Cederbaum 2000, Mu et al 2001. These fatty acids may be inducing apoptosis either by reducing Bcl2 expression or hetero-dimerization of Bax proteins.…”

Section: Discussionmentioning

confidence: 99%

Vitamin A supplementation induces adipose tissue loss through apoptosis in lean but not in obese rats of the WNIN/Ob strain

Jeyakumar

Vajreswari²,

Sesikeran³

et al. 2005

Journal of Molecular Endocrinology

View full text Add to dashboard Cite

Vitamin A is a known regulator of adipose tissue growth. In this paper, we report the possible role of dietary vitamin A supplementation in the regulation of adipose tissue mass, using a novel obese rat model of the WNIN/Ob strain developed at the National Centre for Laboratory Animal Sciences of the National Institute of Nutrition, India. Twenty-four male lean and obese rats of the WNIN/Ob strain were broadly divided into two groups at 7 months of age; each group was subdivided into two subgroups consisting of six lean and six obese rats and they were given diets containing either 2·6 mg or 129 mg vitamin A/kg diet for 2 months. Feeding a high but non-toxic dose of vitamin A (129 mg/kg diet) resulted in a significant reduction in the adiposity index and retroperitoneal white adipose tissue (RPWAT) weight in obese rats while a marginal reduction was observed in lean rats. Further, this treatment resulted in a significantly increased RPWAT apoptotic index and Bax protein expression and a decreased expression of Bcl2 in the lean rats. However, no such changes were observed in the RPWAT of the obese rats subjected to identical treatment. Thus, our data suggests that chronic dietary vitamin A supplementation at a high dose effectively regulates adipose tissue mass both in the lean and obese phenotypes of the WNIN/Ob rat strain, perhaps through different mechanisms.

show abstract

Section: Discussionmentioning

confidence: 99%

Vitamin A supplementation induces adipose tissue loss through apoptosis in lean but not in obese rats of the WNIN/Ob strain

Jeyakumar

Vajreswari²,

Sesikeran³

et al. 2005

Journal of Molecular Endocrinology

View full text Add to dashboard Cite

show abstract

“…37 Phosphorylation of MAPKp42/44 and AKT provides molecular evidence that MP interact with the target cells and activate several signaling cascades that increase both cell survival and proliferation. [49][50][51]54 Most likely, MP contain components that alone or in combination are responsible for the effects observed, although the particular components responsible for each specific effect remain to be elucidated.…”

Section: Mp -Platelet-derived MVmentioning

confidence: 99%

“…37 We postulate that it could be related partly to high-molecular weight, relatively temperaturestable proteins and partly to bioactive lipids conjugated with high-molecular weight proteins. Unsaturated acids, however, have been found to induce apoptosis 54 and inhibit proliferation 55 in several experimental systems. Hence, further work is needed to identify the constituents of MP that are responsible for increasing the survival of hematopoietic cells, and a better understanding of the role MP play in hematopoiesis could help us to develop novel therapeutic approaches.…”

Section: Mp -Platelet-derived MVmentioning

confidence: 99%

Membrane-derived microvesicles: important and underappreciated mediators of cell-to-cell communication

et al. 2006

View full text Add to dashboard Cite

“…Cytosolic phospholipase A 2 (cPLA 2 , 85-kD) is responsible for the release of arachidonic acid (AA), a precursor for the synthesis of eicosanoids and bioactive lipid mediators, from cellular phospholipids in many cell types in response to a variety of physiological and pharmacological agonists. AA and its metabolites play an important role in a variety of biological processes, including signal transduction, chemotaxis, cell proliferation, differentiation, apoptosis and testicular steroidogenesis [42,50]. AA may be involved in apoptosis in vascular smooth muscle [39] and also influence cellular processes at a molecular level, capable of modulating breast cancer cell growth [9].…”

mentioning

confidence: 99%

Alterations of Activities of Cytosolic Phospholipase A2 and Arachidonic Acid-Metabolizing Enzymes in Di-(2-Ethylhexyl)Phthalate-Induced Testicular Atrophy

Kim

Ishizuka

Kazusaka

et al. 2004

The Journal of Veterinary Medical Science

View full text Add to dashboard Cite

ABSTRACT. Di-(2-ethylhexyl) phthalate (DEHP), a peroxisome proliferator-activated receptor α (PPARα) ligand, alters the lipid composition of rat testis, yet the mechanism is unclear. In this study, we investigated the effect of DEHP on the synthesis and metabolism of arachidonic acid (AA), a precursor of eicosanoids, in the testis of prepubertal rats. DEHP (100 and 1,000 mg/kg, 5 days) admini stration caused a significant reduction in activity of cytosolic phospholipase A 2 (cPLA 2 ), the rate-limiting enzyme in the AA and eicosanoid synthesis pathways. DEHP increased the expression of 12-lipoxygenase (12-LOX) in rat testis, whereas cyclooxygenase-2 (COX-2) expr ession was not altered. Cytochrome P450 4A1 (CYP4A1), a product of a PPARα-regulated gene, was markedly increased in the testis by DEHP administration. Taken together, DEHP suppresses cPLA 2 activity and induces the AA metabolizing enzymes such as 12-LOX and CYP4A1, resulting in the reduction of AA level. These data suggest that altered AA metabolic cascades may be related to the decrease of testosterone concentration in DEHP-induced testicular atrophy. KEY WORDS: arachidonic acid, cytosolic phospholipase A 2 , di-(2-ethylhexyl) phthalate, 12-lipoxygenase, testis.J. Vet. Med. Sci. 66(9): 1119-1124, 2004 The exposure of animals to phthalate esters can result in a significant perturbation of normal lipid metabolism in liver, heart, testis, adrenal gland and brain [4]. The plasticizer, di-(2-ethylhexyl) phthalate (DEHP), is a widespread environmental chemical due to its common use in the production of plastic medical devices and food packaging. On the exposure to phthalates for the human, certain populations may be exposed to much higher levels. The range of DEHP concentrations in medical devises are 3.1-650 mg/L [49]. Patients undergoing hemodialysis or blood transfusion received as much as 0.5-360 mg or 14-600 mg of DEHP via plastic medical devices, respectively [17,23]. Ingestion of DEHP, a peroxisome proliferator-activated receptor α (PPARα) ligand, by rats resulted in the increase of non-esterified fatty acids and phospholipids and changes in lipid composition in the testis [36]. Actually, altered lipid metabolism in the testis is frequently associated with testicular atrophy [11].Peroxisomes are ubiquitous eukaryotic organelles that play a key role in regulating lipid homeostasis in mammals. A peroxisome proliferator induces a broad spectrum of responses such as cell proliferation, decreased apoptosis, altered estradiol levels, increased metabolism of fatty acids and eicosanoids and carcinogenesis in the rodent liver [12]. DEHP activates many genes involved in lipid metabolism including fatty acyl-CoA oxidase, 3-ketoacyl-CoA thiolase and cytochrome P450 4A1 (CYP4A1) through PPAR in the liver [3]. Although DEHP is a well-known reproductive toxicant, the mechanism of its toxicity on lipid metabolism in the testis is still unclear.Phospholipase A 2 represents a large superfamily of enzymes that catalyze the hydrolysis of phospholipids at the sn-2 positio...

show abstract

Apoptosis in human primary brain tumours: actions of arachidonic acid

Cited by 51 publications

References 17 publications

Vitamin A supplementation induces adipose tissue loss through apoptosis in lean but not in obese rats of the WNIN/Ob strain

Vitamin A supplementation induces adipose tissue loss through apoptosis in lean but not in obese rats of the WNIN/Ob strain

Membrane-derived microvesicles: important and underappreciated mediators of cell-to-cell communication

Alterations of Activities of Cytosolic Phospholipase A2 and Arachidonic Acid-Metabolizing Enzymes in Di-(2-Ethylhexyl)Phthalate-Induced Testicular Atrophy

Contact Info

Product

Resources

About