|
|
Characterization of metabolic effects of dietary omega-3 fatty acids in transgenic PPARα-humanized mice
Kalendová, Veronika ; Rossmeisl, Martin (advisor) ; Šilhavý, Jan (referee)
Obesity is tightly connected with metabolic diseases including insulin resistance, type 2 diabetes or dyslipidemia. Peroxisome proliferator-activated receptor (PPAR)-α is a key transcription factor involved in the regulation of lipid metabolism, while its activity is stimulated by a variety of hypolipidemic drugs. n-3 polyunsaturated fatty acids (PUFA), including eicosapentaenoic (EPA) and docosahexaenoic (DHA) acid, are endogenous ligands of PPARα, and they are used in the form of fish oil as dietary supplements in order to lower blood lipid levels and to prevent cardiovascular disease. Wax esters represent a novel lipid form of EPA and DHA, and according to recent studies they could exert more potent effects than the classical fish oil (i.e. triacylglycerols). Mice of the 129S1/SvImJ inbred strain were used in the present experiment, and included wild-type (WT) mice, as well as transgenic mice either with the exclusive expression of the human form of PPARα (hPPARα) or mice completely lacking PPARα (PPARα-KO). Mice were fed for 8 weeks the following diets: (i) a control low-fat diet, (ii) obesogenic high-fat diet (cHF), and (iii) the cHF diet supplemented with the n-3 PUFA concentrate in the form of wax esters isolated from marine zooplankton Calanus finmarchicus (ω3Cal). Mice were subjected to...
|
|
|
Dysregulation of the endocannabinoid system in obesity and its modulation by dietary omega-3 fatty acids
Kalendová, Veronika ; Rossmeisl, Martin (advisor) ; Hlaváčková, Markéta (referee)
Obesity is associated with metabolic complications including insulin resistance, dyslipidemia and hypertension (metabolic syndrome). The endocannabinoid system (ECS) activity is elevated in obesity, which can further potentiate metabolic impairments. Pharmacological treatment based on the cannabinoid receptor CB1 blockade led to a decrease in body weight and significant improvements of metabolic parameters in obese individuals. However, parallel effects on the central nervous system resulted in unwanted side-effects including anxiety and depressive moods. Recent experimental studies suggested that dietary interventions with omega-3 polyunsaturated fatty acids of marine origin (EPA, DHA) can decrease the ECS activity in peripheral tissues (adipose, liver, pancreas), and thus partially protect against metabolic disturbances in obesity. One of the underlying mechanisms behind the effects of EPA and DHA could be a replacement of arachidonic acid from the sn-2 position of membrane phospholipids, thereby reducing the substrate availability for the synthesis of endocannabinoid molecules. Key words: omega-3 fatty acids, obesity, endocannabinoid system, 2-arachidonoylglycerol, anandamide
|
guest ::
