title: Branched-chain amino acid ratios in low-protein diets regulate the free amino acid profile and the expression of hepatic fatty acid metabolism-related genes in growing pigs.
abstract: Liver metabolism is affected by nutrients. The aim of this study was to explore the effects of low-protein diets (17% crude protein, CP) supplemented with branched-chain amino acids (BCAAs), including leucine (Leu), isoleucine (Ile) and valine (Val), on hepatic amino acid profile and lipid metabolism in growing pigs. The ratio of Leu : Ile : Val in all groups was 1 : 0.51 : 0.63 (20% crude protein, CP), 1 : 1 : 1 (17% CP), 1 : 0.75 : 0.75 (17% CP), 1 : 0.51 : 0.63 (17% CP) and 1 : 0.25 : 0.25 (17% CP) respectively. Results revealed that compared to the positive control group (1 : 0.51 : 0.63, 20% CP), the low-protein diets significantly augmented the concentrations of most essential amino acids and non-essential amino acids (p < .05), with the greatest values observed in the 1 : 0.25 : 0.25 group. Moreover, relative to the control, the low-protein diets with the Leu : Ile : Val ratio ranging from 1 : 0.75 : 0.75 to 1 : 0.25 : 0.25 markedly downregulated the mRNA abundance of acetyl-CoA carboxylase (ACC), lipoprotein lipase (LPL) and fatty acid-binding protein 4 (FABP-4) (p < .05), and upregulated the mRNA expression of hormone-sensitive lipase (HSL), peroxisome proliferator-activated receptor-g coactivator-1α (PGC-1α), uncoupling protein 3 (UCP3) and liver carnitine palmitoyltransferase 1 (L-CPT-1) (p < .05). Therefore, our data suggest that protein-restricted diets supplemented with optimal BCAA ratio, that is, 1 : 0.75 : 0.75-1 : 0.25 : 0.25, induce a shift from fatty acid synthesis to fatty acid oxidation in the liver of growing pigs. These effects may be associated with increased mitochondrial biogenesis.
authors.affiliation: Key Laboratory of Agro-ecological Processes in Subtropical Region, Institute of Subtropical Agriculture, Chinese Academy of Sciences, Changsha, Hunan, China.|National Engineering Laboratory for Pollution Control and Waste Utilization in Livestock and Poultry Production, Changsha, Hunan, China.|Hunan Provincial Engineering Research Center for Healthy Livestock and Poultry Production, Changsha, Hunan, China.|Scientific Observing and Experimental Station of Animal Nutrition and Feed Science in South-Central, Ministry of Agriculture, Changsha, Hunan, China.|University of Chinese Academy of Sciences, Beijing, China.
authors.forename: Y H
authors.identifier: http://orcid.org/0000-0002-6131-2855
authors.initials: YH
authors.lastname: Duan
authors.affiliation: Key Laboratory of Agro-ecological Processes in Subtropical Region, Institute of Subtropical Agriculture, Chinese Academy of Sciences, Changsha, Hunan, China.|National Engineering Laboratory for Pollution Control and Waste Utilization in Livestock and Poultry Production, Changsha, Hunan, China.|Hunan Provincial Engineering Research Center for Healthy Livestock and Poultry Production, Changsha, Hunan, China.|Scientific Observing and Experimental Station of Animal Nutrition and Feed Science in South-Central, Ministry of Agriculture, Changsha, Hunan, China.|Hunan Co-Innovation Center of Animal Production Safety, CICAPS, Changsha, Hunan, China.|Hunan Collaborative Innovation Center for Utilization of Botanical Functional Ingredients, Changsha, Hunan, China.
authors.forename: F N
authors.initials: FN
authors.lastname: Li
authors.affiliation: Laboratory of Animal Nutrition and Human Health, School of Biology, Hunan Normal University, Changsha, Hunan, China.
authors.forename: C Y
authors.initials: CY
authors.lastname: Wen
authors.affiliation: Laboratory of Animal Nutrition and Human Health, School of Biology, Hunan Normal University, Changsha, Hunan, China.
authors.forename: W L
authors.initials: WL
authors.lastname: Wang
authors.affiliation: Key Laboratory of Agro-ecological Processes in Subtropical Region, Institute of Subtropical Agriculture, Chinese Academy of Sciences, Changsha, Hunan, China.|National Engineering Laboratory for Pollution Control and Waste Utilization in Livestock and Poultry Production, Changsha, Hunan, China.|Hunan Provincial Engineering Research Center for Healthy Livestock and Poultry Production, Changsha, Hunan, China.|Scientific Observing and Experimental Station of Animal Nutrition and Feed Science in South-Central, Ministry of Agriculture, Changsha, Hunan, China.|University of Chinese Academy of Sciences, Beijing, China.
authors.forename: Q P
authors.initials: QP
authors.lastname: Guo
authors.affiliation: Key Laboratory of Agro-ecological Processes in Subtropical Region, Institute of Subtropical Agriculture, Chinese Academy of Sciences, Changsha, Hunan, China.|National Engineering Laboratory for Pollution Control and Waste Utilization in Livestock and Poultry Production, Changsha, Hunan, China.|Hunan Provincial Engineering Research Center for Healthy Livestock and Poultry Production, Changsha, Hunan, China.|Scientific Observing and Experimental Station of Animal Nutrition and Feed Science in South-Central, Ministry of Agriculture, Changsha, Hunan, China.|University of Chinese Academy of Sciences, Beijing, China.
authors.forename: Y H
authors.initials: YH
authors.lastname: Li
authors.affiliation: Key Laboratory of Agro-ecological Processes in Subtropical Region, Institute of Subtropical Agriculture, Chinese Academy of Sciences, Changsha, Hunan, China.|National Engineering Laboratory for Pollution Control and Waste Utilization in Livestock and Poultry Production, Changsha, Hunan, China.|Hunan Provincial Engineering Research Center for Healthy Livestock and Poultry Production, Changsha, Hunan, China.|Scientific Observing and Experimental Station of Animal Nutrition and Feed Science in South-Central, Ministry of Agriculture, Changsha, Hunan, China.|Laboratory of Animal Nutrition and Human Health, School of Biology, Hunan Normal University, Changsha, Hunan, China.|College of Animal Science, South China Agricultural University, Guangzhou, China.
authors.forename: Y L
authors.initials: YL
authors.lastname: Yin
mesh_terms: D000596:Amino Acids / Q000008:administration & dosage / Q000097:blood / Q000378:metabolism*; D000818:Animals; D004044:Dietary Proteins / Q000008:administration & dosage*; D005227:Fatty Acids / Q000378:metabolism*; D005786:Gene Expression Regulation / Q000187:drug effects*; D008099:Liver / Q000378:metabolism*; D008928:Mitochondria / Q000378:metabolism; D010084:Oxidation-Reduction; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D013552:Swine / Q000502:physiology*
chemical_list: D000596:Amino Acids; D004044:Dietary Proteins; D005227:Fatty Acids; D012333:RNA, Messenger
keywords: amino acid profile; branched-chain amino acids; growing pigs; hepatic lipid metabolism