No data are reported on changes in mitochondrial membrane phospholipids in non-alcoholic fatty liver disease. We determined the content of mitochondrial membrane phospholipids from rats with non alcoholic liver steatosis, with a particular attention for cardiolipin (CL) content and its fatty acid composition, and their relation with the activity of the mitochondrial respiratory chain complexes. Different dietary fatty acid patterns leading to steatosis were explored. With high-fat diet, moderate macrosteatosis was observed and the liver mitochondrial phospholipid class distribution and CL fatty acids composition were modified. Indeed, both CL content and its C18:2n-6 content were increased with liver steatosis. Moreover, mitochondrial ATP synthase activity was positively correlated to the total CL content in liver phospholipid and to CL C18:2n-6 content while other complexes activity were negatively correlated to total CL content and/or CL C18:2n-6 content of liver mitochondria. The lard-rich diet increased liver CL synthase gene expression while the fish oil-rich diet increased the (n-3) polyunsaturated fatty acids content in CL. Thus, the diet may be a significant determinant of both the phospholipid class content and the fatty acid composition of liver mitochondrial membrane, and the activities of some of the respiratory chain complex enzymes may be influenced by dietary lipid amount in particular via modification of the CL content and fatty acid composition in phospholipid.
"The composition of mitochondrial CL was found to be altered by both quantity and quality of the dietary fat . In hepatocytes, the composition of mitochondrial CL was altered in rats fed 30% fat diets in comparison to rats fed 5% fat diets. "
[Show abstract][Hide abstract] ABSTRACT: Mitochondrial membrane phospholipids are essential for the mitochondrial architecture, the activity of respiratory proteins, and the transport of proteins into the mitochondria. The accumulation of phospholipids within mitochondria depends on a coordinate synthesis, degradation, and trafficking of phospholipids between the endoplasmic reticulum (ER) and mitochondria as well as intramitochondrial lipid trafficking. Several studies highlight the contribution of dietary fatty acids to the remodeling of phospholipids and mitochondrial membrane homeostasis. Understanding the role of phospholipids in the mitochondrial membrane and their metabolism will shed light on the molecular mechanisms involved in the regulation of mitochondrial function and in the mitochondrial-related diseases.
International Journal of Cell Biology 01/2014; 2014(6):709828. DOI:10.1155/2014/709828
[Show abstract][Hide abstract] ABSTRACT: Metabolic syndrome is closely related to erectile dysfunction (ED), and hyperlipidaemia is considered a major risk factor for ED. Adenosine triphosphate (ATP) synthase is believed to play an important role in metabolic syndrome; it has been hypothesised that ATP synthase contributes to ED development. We have verified this hypothesis using primary cultured human corpus cavernosum smooth muscle (HCCSM) cells treated with excessive free fat acid (FFA) and a high-fat diet (HFD) mouse model. Our results showed that high fatty factors could cause lipid accumulation in HCCSM cells, which could result in abnormal lipid metabolism, such as high levels of triglycerides, cholesterol and glucose in the HFD mice. There was a remarkable down-regulation of ATP synthase and p-Akt after in vivo and in vitro excessive FFA treatments. These results indicated that abnormal lipid metabolism could induce ATP synthase down-regulation via the Akt phosphorylation pathway and that ATP synthase may be a target of lipotoxicity in corpus cavernosum smooth muscle cells.
[Show abstract][Hide abstract] ABSTRACT: The incidence of metabolic syndrome components including obesity, lipid deregulation, insulin resistance (IR) and non-alcoholic fatty liver disease is increasing rapidly in wealthy societies. The present study was designed to determine the effect of different nutritional lipid patterns (quantity and quality) on lipid utilisation and oxidative stress in the liver and muscle of rats in an integrated fashion. A total of forty-eight Wistar male rats were fed for 12 weeks with a mixed, lard or fish-oil diet, containing either 50 or 300 g lipid/kg. Rats developed liver steatosis associated with moderate liver injury when fed the 30 % lipid diets, in spite of the absence of overt obesity or IR, except when fed the lard 30 % lipid diet. The intake of the 30 % lipid diets decreased hepatic lipogenesis and mitochondriogenesis and increased lipid peroxidation and protein oxidation. Surprisingly, muscle lipid content was not modified whatever the administered diet. The intake of the 30 % lipid diets increased the muscle protein expression of fatty acid (FA) translocase/cluster of differentiation 36 (FAT/CD36), PPARγ co-activator 1α (PGC-1α) and muscle carnitine palmitoyltransferase 1 (m-CPT1), reflecting increased FA transport in the muscle associated with increased oxidative metabolism. The lard 30 % lipid diet led to IR without modifying the muscle lipid content. The fish-oil 30 % lipid diet failed to prevent the development of hepatic steatosis and made the tissues more prone to oxidation. Overall, the present study suggests that the FA composition of muscle is more important than lipid accumulation itself in the modulation of insulin sensitivity, and indicates that precaution should be taken when advising an unphysiologically high (pharmacological) supplementation with long-chain n-3 PUFA.
The British journal of nutrition 05/2013; 110(10):1-14. DOI:10.1017/S0007114513001311 · 3.45 Impact Factor
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