Dietary Conjugated Linoleic Acids Alter Adipose Tissue and Milk Lipids of Pregnant and Lactating Sows

Background/Aims: Conjugated linoleic acids (CLAs) are known to induce apoptosis in adipocytes; however, the cellular mechanisms involved remained illdefined. We explored the different apoptotic induction effects of two CLA isomers on adipocytes and then investigated the expression and function of microRNAs (miRNAs) related to the apoptosis. Methods: TUNEL and FCM assays were used to detect CLAs-induced adipocyte apoptosis. Microarrays were used to compare the differential expression of miRNAs. MiR-23a, a miRNA that showed significant changes in expression in the CLA-treated cells, was selected for the subsequent functional studies via over-expression and knock down in in vivo and in vitro experiments. Results: C9, t11-CLA exhibited a stronger induction of apoptosis in the differentiated 3T3-L1 adipocytes than t10, c12-CLA. However, t10, c12-CLA could rapidly activate NF-κB, which may have caused their different apoptotic effects. MiR-23a was markedly down-regulated by the CLAs treatment and miR-23a over-expression attenuated CLA-induced apoptosis. Apoptosis protease-activating factor 1 (APAF1) was identified as a target gene of miR-23a. In an in vivo experiment endogenous miR-23a was down-regulated in mice fed with a mixture of both CLAs. The mice also exhibited less fat deposition and more apoptotic fat cells in adipose tissue. Moreover, endogenous miR-23a was suppressed in mice via intravenous injection with an antagomir which resulted in decreased body weight, increased number of apoptotic fat cells and increased APAF1 expression in adipose tissue. Conclusion: Taken together, our results suggest that miR-23a plays a critical role in CLA-induced apoptosis in adipocytes via controlling APAF1 expression.

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Influence of dietary conjugated linoleic acids and vitamin E on meat quality, and adipose tissue in rabbits

Meat Science ◽

10.1016/j.meatsci.2006.10.007 ◽

2007 ◽

Vol 76 (1) ◽

pp. 19-28 ◽

Cited By ~ 32

Author(s):

C. Corino ◽

D.P. Lo Fiego ◽

P. Macchioni ◽

G. Pastorelli ◽

A. Di Giancamillo ◽

...

Keyword(s):

Adipose Tissue ◽

Vitamin E ◽

Meat Quality ◽

Conjugated Linoleic Acids

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Conjugated linoleic acid and trans C18:1 in muscle and adipose tissue of lambs fed supplements containing n-3 polyunsaturated fatty acids

Proceedings of the British Society of Animal Science ◽

10.1017/s1752756200008383 ◽

2002 ◽

Vol 2002 ◽

pp. 182-182

Author(s):

M. Enser ◽

A.M. Wachira ◽

L.A. Sinclair ◽

R.G Wilkinson ◽

K.G. Hallett ◽

...

Keyword(s):

Fatty Acids ◽

Adipose Tissue ◽

Linoleic Acid ◽

Polyunsaturated Fatty Acids ◽

Fish Oil ◽

Unsaturated Fatty Acids ◽

Vaccenic Acid ◽

Conjugated Linoleic Acids ◽

Relationship Of ◽

The Relationship

Conjugated linoleic acids (CLA) occur in the milk and tissues of ruminants. Although cis-9, trans-11 CLA is an intermediate in the biohydrogenation of linoleic acid in the rumen, duodenal flows of CLA are very low (Scollan et al, 2001) and most CLA appears to be synthesised in tissues from trans-11 C18:1 (vaccenic acid) (Griinari et al, 2000). Trans C18:1 isomers are also produced in the rumen and their amounts are increased when the levels of dietary unsaturated fatty acids are raised. We have investigated the relationship of tissue levels of CLA and trans C18:1 in three breeds of lambs fed supplements of linseed or fish oil to increase trans C18:1.

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Targets and procedures for altering ruminant meat and milk lipids

Proceedings of The Nutrition Society ◽

10.1017/s0029665199000786 ◽

1999 ◽

Vol 58 (3) ◽

pp. 593-607 ◽

Cited By ~ 139

Author(s):

D. Demeyer ◽

M. Doreau

Keyword(s):

Fatty Acids ◽

Adipose Tissue ◽

Fatty Acid ◽

Polyunsaturated Fatty Acids ◽

Milk Fat ◽

Lipid Fraction ◽

Conjugated Linoleic Acids ◽

Fat Depots ◽

Tissue Lipids ◽

Ruminant Meat

Beef and dairy products suffer from a negative health image, related to the nature of their lipid fraction. Rumen lipid metabolism involves the presence of saturated lipids in ruminant tissues. Lipolysis, fatty acid biohydrogenation and formation of microbial fatty acids in the rumen and their effects on rumen outflow of fatty acids are discussed. Special emphasis is given to the formation of trans-fatty acids and the possibilities of decreasing biohydrogenation. Small differences in intestinal digestibilities of fatty acids are mentioned, followed by a discussion on transfer of absorbed fatty acids into milk and adipose tissue lipids. The preferential retention of polyunsaturated fatty acids as well as the balance between synthesis and incorporation of fatty acids in tissues is described. Dietary means for the modification of milk fat are listed, with special emphasis on the possibilities for enrichment in polyunsaturated fatty acids and the presence of conjugated linoleic acids. A description of the nature and development of fat depots in beef cattle is followed by a discussion of breed, conformation and feed effects on adipose tissue distribution and fatty acid composition. Special emphasis is given to the very lean Belgian Blue double-muscled breed. The review ends with a consideration of the limits to the modification of ruminant fats, involving considerations of consumer acceptance as well as animal welfare and environmental effects.

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