scholarly journals CD36 regulates fatty acid composition and sensitivity to insulin in 3T3-L1 adipocytes

2007 ◽  
pp. 493-496
Author(s):  
K Kontrová ◽  
J Zídková ◽  
B Bartoš ◽  
V Skop ◽  
J Sajdok ◽  
...  

In the current study, we tested a hypothesis that CD36 fatty acid (FA) transporter might affect insulin sensitivity by indirect effects on FA composition of adipose tissue. We examined the effects of CD36 downregulation by RNA interference in 3T3-L1 adipocytes on FA transport and composition and on sensitivity to insulin action. Transfected 3T3-L1 adipocytes, without detectable CD36 protein, showed reduced neutral lipid levels and significant differences in FA composition when levels of essential FA and their metabolites were lower or could not be detected including gamma linolenic (C18:3 n6), eicosadienic (C20:2 n6), dihomo-gamma linolenic (C20:3 n6), eicosapentaenoic (EPA) (C20:5 n3), docosapentaenoic (DPA) (C22:5 n3), and docosahexaenoic (DHA) (C22:6 n3) FA. Transfected 3T3-L1 adipocytes exhibited a significantly higher n6/n3 FA ratio, reduced 5-desaturase and higher 9-desaturase activities. These lipid profiles were associated with a significantly reduced insulin-stimulated glucose uptake (4.02+/-0.1 vs. 8.42+/-0.26 pmol.10(-3) cells, P=0.001). These findings provide evidence that CD36 regulates FA composition thereby affecting sensitivity to insulin action in 3T3-L1 adipocytes.

2009 ◽  
Vol 201 (1) ◽  
pp. 67-74 ◽  
Author(s):  
Fátima Pérez de Heredia ◽  
Elvira Larqué ◽  
Salvador Zamora ◽  
Marta Garaulet

Dehydroepiandrosterone (DHEA) is reported to exert beneficial effects, such as protection from cardiovascular risk and lowering serum insulin levels. Adipose tissue (AT) is a target for DHEA actions, and the hormone can also affect hepatic fatty acid (FA) metabolism. FAs are involved in the development of insulin resistance; thus, there might be a relationship between DHEA, FA, and insulin. However, few data are available regarding DHEA and FA composition, especially concerning AT. Seventeen-month old female Sprague–Dawley rats (n=11; controls: n=10) were treated with DHEA (0.5% w/w in the diet) for 13 weeks, after which serum, periovarian, mesenteric, s.c., and brown AT were analyzed for FA composition. DHEA treatment resulted in significant changes in FA profiles in serum and adipose depots, like reduced 16:1n-7 (s.c. and brown AT; P<0.01), elevated n-9 monounsaturated FA (serum and s.c. AT; P<0.05), diminished n-6 polyunsaturated FA (PUFA; general; P<0.05) and increased n-3 PUFA (brown AT; P<0.01), along with lower n-6/n-3 ratios (s.c. and brown AT; P<0.05, P<0.01 respectively). DHEA modified estimates of desaturase activities, decreasing stearoyl-CoA-desaturase markers in s.c., and brown AT (P<0.05) and increasing those of delta-6-desaturase in serum and AT (P<0.05). In addition, DHEA-treated rats showed lower serum insulin levels (P<0.05). We have demonstrated for the first time that DHEA induces significant modifications in AT fatty acid composition in vivo, mainly concerning unsaturated FAs, and changes occurred in a tissue-dependent manner. We propose that these changes may be related to the capacity of DHEA to lower serum insulin levels.


1985 ◽  
Vol 54 (03) ◽  
pp. 563-569 ◽  
Author(s):  
M K Salo ◽  
E Vartiainen ◽  
P Puska ◽  
T Nikkari

SummaryPlatelet aggregation and its relation to fatty acid composition of platelets, plasma and adipose tissue was determined in 196 randomly selected, free-living, 40-49-year-old men in two regions of Finland (east and southwest) with a nearly twofold difference in the IHD rate.There were no significant east-southwest differences in platelet aggregation induced with ADP, thrombin or epinephrine. ADP-induced platelet secondary aggregation showed significant negative associations with all C20-C22 ω3-fatty acids in platelets (r = -0.26 - -0.40) and with the platelet 20: 5ω3/20: 4ω 6 and ω3/ ω6 ratios, but significant positive correlations with the contents of 18:2 in adipose tissue (r = 0.20) and plasma triglycerides (TG) (r = 0.29). Epinephrine-induced aggregation correlated negatively with 20: 5ω 3 in plasma cholesteryl esters (CE) (r = -0.23) and TG (r = -0.29), and positively with the total percentage of saturated fatty acids in platelets (r = 0.33), but had no significant correlations with any of the ω6-fatty acids. Thrombin-induced aggregation correlated negatively with the ω3/6ω ratio in adipose tissue (r = -0.25) and the 20: 3ω6/20: 4ω 6 ratio in plasma CE (r = -0.27) and free fatty acids (FFA) (r = -0.23), and positively with adipose tissue 18:2 (r = 0.23) and 20:4ω6 (r = 0.22) in plasma phospholipids (PL).The percentages of prostanoid precursors in platelet lipids, i. e. 20: 3ω 6, 20: 4ω 6 and 20 :5ω 3, correlated best with the same fatty acids in plasma CE (r = 0.32 - 0.77) and PL (r = 0.28 - 0.74). Platelet 20: 5ω 3 had highly significant negative correlations with the percentage of 18:2 in adipose tissue and all plasma lipid fractions (r = -0.35 - -0.44).These results suggest that, among a free-living population, relatively small changes in the fatty acid composition of plasma and platelets may be reflected in significant differences in platelet aggregation, and that an increase in linoleate-rich vegetable fat in the diet may not affect platelet function favourably unless it is accompanied by an adequate supply of ω3 fatty acids.


2013 ◽  
Vol 53 (4) ◽  
pp. 1029-1037 ◽  
Author(s):  
A. Giuliani ◽  
F. Ferrara ◽  
M. Scimò ◽  
F. Angelico ◽  
L. Olivieri ◽  
...  

1987 ◽  
Vol 76 (1) ◽  
pp. 87-90 ◽  
Author(s):  
G. E. ANDERSEN ◽  
N. C. CHRISTENSEN ◽  
M. B. V. PETERSEN ◽  
K. B. JOHANSEN

2011 ◽  
Vol 138 (1-3) ◽  
pp. 1-12 ◽  
Author(s):  
F. Leiber ◽  
R. Hochstrasser ◽  
H.-R. Wettstein ◽  
M. Kreuzer

Sign in / Sign up

Export Citation Format

Share Document