Dietary supplementation with long-chain monounsaturated fatty acids attenuates obesity-related metabolic dysfunction and increases expression of PPAR gamma in adipose tissue in type 2 diabetic KK-Ay mice

Zhi-Hong Yang,Yusuke Iwasaki,Jiro Takeo,Hiroko Miyahara,Masashi Katayama

doi:10.1186/1743-7075-10-16

Zhi-Hong Yang, Yusuke Iwasaki + Show 3 more

Open Access

https://doi.org/10.1186/1743-7075-10-16

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Journal: Nutrition & Metabolism	Publication Date: Jan 1, 2013
Citations: 93	License type: cc-by

Affiliation: Nippon Suisan Kaisha (Japan)

Abstract

The objective of present study was to examine the effect of long-chain monounsaturated fatty acids (LC-MUFAs) with chain lengths longer than 18 (i.e., C20:1 and C22:1 isomers combined) on obesity-related metabolic dysfunction and its molecular mechanisms. Type-2 diabetic KK-Ay mice (n = 20) were randomly assigned to the 7% soybean oil-diet group (control group) and 4% LC-MUFA concentrate-supplemented-diet group (LC-MUFA group). At 8 weeks on the diet, the results showed that plasma, liver and adipose tissue levels of C20:1 and C22:1 isomers increased significantly with LC-MUFA treatment. Supplementation with LC-MUFAs markedly reduced white fat pad weight as well as adipocyte size in the mice. The levels of plasma free fatty acids, insulin, and leptin concentration in the obese diabetic mice of the LC-MUFA group were also decreased as compared with the mice in the soybean oil-diet control group. Dietary LC-MUFAs significantly increased the mRNA expression of peroxisome proliferator-activated receptor gamma (Pparg), lipoprotein lipase (Lpl), fatty acid transport protein (Fatp), fatty acid translocase/CD36 (Cd36), as well as mRNA expression of genes involved in lipid oxidation such as carnitine palmitoyltransferase-1A (Cpt1a) and citrate synthase (Cs), and decreased the mRNA expression of inflammatory marker serum amyloid A 3 (Saa3) in the adipose tissues of diabetic mice. The results suggest that LC-MUFAs may ameliorate obesity-related metabolic dysfunction partly through increased expression of Pparg as well as its target genes, and decreased inflammatory marker expression in white adipose tissue.

Highlights

Type 2 diabetes mellitus (DM) is a major global health problem and one of the major causes of morbidity and mortality
Besides Long-chain monounsaturated fatty acid (LC-monounsaturated fatty acids (MUFAs)), saury and pollock oils are rich in n-3 polyunsaturated fatty acid (PUFA) such as eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), and it is not clear whether these protective effects were directly attributable to LC-MUFAs
We showed that dietary administration of LC-MUFAs for 8 weeks attenuated hyperinsulinemia and hyperlipidemia and decreased fat pad weight in diabetic KK-Ay mice

Summary

Introduction

Type 2 diabetes mellitus (DM) is a major global health problem and one of the major causes of morbidity and mortality. The pathogenesis of type 2 DM is complex, involving progressive development of insulin resistance in peripheral tissues accompanied by defective insulin secretion from oleic acid or palmitoleic acid. As such, it is unclear whether MUFAs of greater chain length (> C18) have beneficial effects on obesity-related DM. To investigate the effects of LC-MUFAs on metabolic syndrome, we further produced a LC-MUFA concentrate derived from saury oil, and found that the LC-MUFA–supplemented diet improved symptoms of metabolic syndrome in diet-induced obese mice [21] It remains unknown whether dietary LC-MUFAs ameliorate obesity-related metabolic dysfunctions in experimental animals with type 2 DM

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