Changes in tissue fatty acid composition in murine malignancy and following anticancer therapy

The role of mediastinal adipose tissue 11β-hydroxysteroid d ehydrogenase type 1 and glucocorticoid expression in the development of coronary atherosclerosis in obese patients with ischemic heart disease

Background

Visceral fat deposition and its associated atherogenic complications are mediated by glucocorticoids. Cardiac visceral fat comprises mediastinal adipose tissue (MAT) and epicardial adipose tissue (EAT), and MAT is a potential biomarker of risk for obese patients.

Aim

Our objective was to evaluate the role of EAT and MAT 11beta-hydroxysteroid dehydrogenase type 1 (11β-HSD-1) and glucocorticoid receptor (GCR) expression in comparison with subcutaneous adipose tissue (SAT) in the development of coronary atherosclerosis in obese patients with coronary artery disease (CAD), and to assess their correlations with CD68 and fatty acids from these tissues.

Methods and results

Expression of 11β-HSD-1 and GCR was measured by qRT-PCR in EAT, MAT and SAT of thirty-one obese patients undergoing coronary artery bypass grafting due to CAD (obese CAD group) and sixteen obese patients without CAD undergoing heart valve surgery (controls). 11β-HSD-1 and GCR expression in MAT were found to be significantly increased in the obese CAD group compared with controls (p < 0.05). In the obese CAD group, 11β-HSD-1 and GCR mRNA levels were strongly correlated in MAT. Stearidonic acid was significantly increased in EAT and MAT of the obese CAD group and arachidonic acid was significantly expressed in MAT of the obese male CAD group (p < 0.05).

Conclusions

We report for the first time the increased expression of 11β-HSD-1 and GCR in MAT compared with EAT and SAT, and also describe the interrelated effects of stearidonic acid, HOMA-IR, plasma cortisol and GCR mRNA levels, explaining 40.2% of the variance in 11β-HSD-1 mRNA levels in MAT of obese CAD patients. These findings support the hypothesis that MAT contributes locally to the development of coronary atherosclerosis via glucocorticoid action.

Effects of dietary linseed, evening primrose or fish oils on fatty acid and prostaglandin E2 contents in the rat livers and 7,12-dimethylbenz[a]anthracene-induced tumours

We examined the influence of diets supplemented with fish and vegetable oils on fatty acid and prostaglandin E2 (PGE2) contents in livers of non-7,12-dimethylbenz[a]anthracene (DMBA)- and DMBA-treated rats, and in DMBA-induced tumours. Decreased concentrations of saturated fatty acids and increased unsaturated fatty acid levels were observed in liver phospholipids of rats fed these oils. There was a marked difference in the concentrations of fatty acids found in the tumours and those present in liver lipids. Oleic acid was the main unsaturated fatty acid found in the tumour tissue. Both liver and tumour PGE2 contents were clearly correlated to the diet. The PGE2 concentrations were decreased in livers and tumours of rats fed fish (FO) and linseed oils (LO).

Fatty acid composition of 19 species of fish from the Black Sea and the Marmara Sea

Evidence suggests that differences in fatty acid composition among various fish species may be due to differences in diet or to environmental factors such as temperature, salinity, and depth at which the fish are caught. The beneficial effects of a diet containing fish on cardiovascular or other diseases have been associated with their high content of eicosapentaenoic (20:5n-3) and docosahexaenoic (22:6n-3) acids. In this study we analyzed the fatty acid composition of the flesh of 18 different species of marine fish and of cultured rainbow trout. The fish were obtained from the Black and the Marmara Seas, both of which have unique biological and ecological systems as well as eutrophication and pollution. The contents of 20:5n-3 and 22:6n-3 in the marine fish ranged from 4.2 to 13.3 wt% of total fatty acids, and from 6.6 to 40.8 wt%, respectively. The most important differences from other studies on oceanic fish were the tendencies toward higher percentages of 16:0 and 22:6n-3. The n-3 series of polyunsaturated fatty acids were present as 32.4+/-1.9% of the total fatty acids. The present study suggests that mature and immature Pomatomus saltator as well as Engraulis encrasicolus, Mullus surmuletus, Sardina pilchardus, Mugil cephalus, and Sarda sarda may be preferred for the Turkish diet as a result of their high 20:5n-3 and 22:6n-3 contents. The cultured rainbow trout Oncorhynchus mykiss is not as good a source of n-3 fatty acids as are the marine fish.

Early postburn fatty acid profile in burn patients

To understand the alterations in lipid metabolism following burn injury, 29 patients with burns, 18 survivors for the first 15 days and 11 non-survivors until death, were studied for total fatty acid (FA) profiles. No specific dietary fat was given. The plasma total FA profile was determined by capillary gas chromatography. The main observations of this survey were that: arachidonic acid decreased by 55.7 per cent (P < 0.0002), and linoleic acid decreased by 31.6 per cent (P < 0.004), more immunosuppressive mediators were probably produced. The elevated levels of both palmitic (12.1 per cent increase, P < 0.02) and oleic acids (63.0 per cent increase, P < 0.0001) in the plasma of burned patients suggested increased lipolysis from depot triglycerides. Eicosatrienoic acid showed decreased levels (49.5 per cent decrease, P < 0.005) at 3-4 days. Docosahexaenoic acid reached its lowest level at postburn days 7-9 (32.1 per cent decrease, P < 0.04). The significant changes of FA profile in patients could be related to the increased activity of fat metabolism. The results of this study have revealed the basic FA changes and requirements. Overfeeding and unnecessary intake of the source of immunosuppressive mediators would be avoided.

Subcutaneous, omentum and tumor fatty acid composition, and serum insulin status in patients with benign or cancerous ovarian or endometrial tumors. Do tumors preferentially utilize polyunsaturated fatty acids?

The relationships between the fatty acid composition of cancerous endometrium and ovary, and peripheral adipose tissues were studied in Israeli Jewish women, and are presented together since no differences were shown between them. The results suggest a mobilization of linoleic acid from subcutaneous and omental depots and its incorporation into tumors accompanied by a high degree of desaturation. High blood insulin concentrations characterized patients with stage I and II disease, and low concentrations characterized patients with advanced degrees of malignancy.