Branched-chain amino acids alleviate nonalcoholic steatohepatitis in rats

2013 ◽  
Vol 38 (8) ◽  
pp. 836-843 ◽  
Author(s):  
Tianrun Li ◽  
Leiluo Geng ◽  
Xin Chen ◽  
Miranda Miskowiec ◽  
Xuan Li ◽  
...  

Nonalcoholic steatohepatitis (NASH) is a prevalent disease in countries around the world. The branched-chain amino acids (BCAAs) leucine, isoleucine, and valine cannot be synthesized by the body and have been shown to promote muscle buildup; thus, it is logical to suggest that BCAAs can reduce fat deposition in the body. We used gonadectomized rats fed a high-fat diet to investigate the effects of BCAAs on lipid metabolism over an 8-week experimental period. Body composition, tissue histology, plasma lipid indices, and hormone levels were examined. We demonstrated that the body weights of rats were not significantly decreased but the mesenteric fat was significantly decreased (p < 0.05) in BCAA-treated rats. In addition, BCAAs decreased plasma lipid levels and fat deposition in the liver. At week 4, when the untreated rats displayed macrovesicular steatosis, BCAA-treated rats had only macrovesicular droplets in their hepatocytes. At week 8, when the untreated rat livers displayed profound inflammation and cirrhosis, BCAA-treated rat livers remained in the macrovesicular stage of steatosis. BCAAs induced higher blood glucose and plasma insulin levels (p < 0.05). BCAAs also improved liver blood flow by increasing mean arterial blood pressure and decreasing portal pressure, which helped delay the change in blood flow pattern to that of cirrhosis. BCAAs also induced the skeletal muscle to express higher levels of branched-chain α-keto acid dehydrogenase E1α, which indicates an enhanced metabolic capacity of BCAAs in muscle tissue. This study clearly demonstrates the effects of BCAAs on the amelioration of fat deposition in rats fed a high-fat diet.

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Chang Ma ◽  
Yajng Liu ◽  
Shaoshuai Liu ◽  
Crystal L. Lévesque ◽  
Fengqi Zhao ◽  
...  

Metabolism ◽  
2017 ◽  
Vol 69 ◽  
pp. 177-187 ◽  
Author(s):  
Takashi Honda ◽  
Masatoshi Ishigami ◽  
Fangqiong Luo ◽  
Ma Lingyun ◽  
Yoji Ishizu ◽  
...  

2021 ◽  
Vol 5 (Supplement_2) ◽  
pp. 529-529
Author(s):  
Chaitra Surugihalli ◽  
Vaishna Muralidaran ◽  
Kruti Patel ◽  
Tabitha Gregory ◽  
Nishanth Sunny

Abstract Objectives Elevated circulating branched-chain amino acids (BCAAs) during insulin resistance are strong predictors of type 2 diabetes mellitus onset. Defects in BCAA degradation are evident in several tissues during insulin resistance and non-alcoholic fatty liver disease (NAFLD). Furthermore, alterations in BCAA metabolism are associated with changes in several aspects lipid metabolism, including lipogenesis, ketogenesis and mitochondrial TCA cycle activity. Considering the crosstalk between BCAAs and lipid metabolism, we hypothesized that chronic supplementation of BCAAs will modulate hepatic insulin resistance and mitochondrial lipid oxidation during NAFLD. Methods Mice (C57BL/6N) were reared on either a low-fat (LF; 10% fat kcal), high-fat (HF; 60% fat kcal or high-fat diet supplemented with BCAA (HFBA; 150% BCAA) for 24 weeks. Metabolic profiling was conducted under fed or overnight fasted (14–16 hrs) conditions. A subset of overnight fasted mice from the HF and HFBA groups were subjected to hyperinsulinemic euglycemic clamps, following implantation of jugular vein catheters. Results Feeding HF and HFBA diets resulted in NAFLD. Circulating BCAAs were higher in ‘fed’ mice consuming HFBA diet (e.g., Valine, µM ± SEM; 311 ± 38 in HF, 432 ± 34 in HFBA, P ≤ 0.05). Overnight fasting significantly reduced BCAA levels in all groups, but the fasting levels of BCAAs remained similar between groups. Fed-to-fasted fold changes in blood glucose, serum insulin and c-peptide were higher in HFBA mice (P ≤ 0.05). Insulin stimulated suppression of glucose production (% ± SEM; HF = 38 ± 11, HFBA = 16 ± 16) was blunted in HFBA mice.  Furthermore, fed-to-fasted expression of hepatic genes involved in lipid oxidation, including LCAD, MCAD, PPARa and CPT1a were significantly higher (P ≤ 0.05) in the HFBA mice. Conclusions In summary, chronic BCAA supplementation induced hepatic lipid oxidation gene expression, without any apparent improvements in insulin sensitivity. In conclusion, while the induction of lipid oxidation by BCAAs could explain certain beneficial effects associated with their supplementation, the longer-term impact of the BCAAs on insulin sensitivity need to be further explored. Funding Sources National Institutes of Health (NIH) grant RO1-DK-112865


2020 ◽  
Author(s):  
Ada Admin ◽  
Huishou Zhao ◽  
Fuyang Zhang ◽  
Dan Sun ◽  
Xiong Wang ◽  
...  

Branched chain amino acids (BCAAs) are associated with the progression of obesity-related metabolic disorders, including T2DM and non-alcoholic fatty liver disease. However, whether BCAAs disrupt the homeostasis of hepatic glucose and lipid metabolism remains unknown. In this study, we observed that BCAAs supplementation significantly reduced high-fat (HF) diet-induced hepatic lipid accumulation while increasing the plasma lipid levels and promoting muscular and renal lipid accumulation. Further studies demonstrated that BCAAs supplementation significantly increased hepatic gluconeogenesis and suppressed hepatic lipogenesis in HF diet-induced obese (DIO) mice. These phenotypes resulted from severe attenuation of Akt2 signaling via mTORC1- and mTORC2-dependent pathways. BCAAs/branched-chain α-keto acids (BCKAs) chronically suppressed Akt2 activation through mTORC1 and mTORC2 signaling and promoted Akt2 ubiquitin-proteasome-dependent degradation through the mTORC2 pathway. Moreover, the E3 ligase Mul1 played an essential role in BCAAs/BCKAs-mTORC2-induced Akt2 ubiquitin-dependent degradation. We also demonstrated that BCAAs inhibited hepatic lipogenesis by blocking Akt2/SREBP1/INSIG2a signaling and increased hepatic glycogenesis by regulating Akt2/Foxo1 signaling. Collectively, these data demonstrate that in DIO mice, BCAAs supplementation resulted in serious hepatic metabolic disorder and severe liver insulin resistance: insulin failed to not only suppress gluconeogenesis but also activate lipogenesis. Intervening BCAA metabolism is a potential therapeutic target for severe insulin-resistant disease.<br>


2020 ◽  
Author(s):  
Ada Admin ◽  
Huishou Zhao ◽  
Fuyang Zhang ◽  
Dan Sun ◽  
Xiong Wang ◽  
...  

Branched chain amino acids (BCAAs) are associated with the progression of obesity-related metabolic disorders, including T2DM and non-alcoholic fatty liver disease. However, whether BCAAs disrupt the homeostasis of hepatic glucose and lipid metabolism remains unknown. In this study, we observed that BCAAs supplementation significantly reduced high-fat (HF) diet-induced hepatic lipid accumulation while increasing the plasma lipid levels and promoting muscular and renal lipid accumulation. Further studies demonstrated that BCAAs supplementation significantly increased hepatic gluconeogenesis and suppressed hepatic lipogenesis in HF diet-induced obese (DIO) mice. These phenotypes resulted from severe attenuation of Akt2 signaling via mTORC1- and mTORC2-dependent pathways. BCAAs/branched-chain α-keto acids (BCKAs) chronically suppressed Akt2 activation through mTORC1 and mTORC2 signaling and promoted Akt2 ubiquitin-proteasome-dependent degradation through the mTORC2 pathway. Moreover, the E3 ligase Mul1 played an essential role in BCAAs/BCKAs-mTORC2-induced Akt2 ubiquitin-dependent degradation. We also demonstrated that BCAAs inhibited hepatic lipogenesis by blocking Akt2/SREBP1/INSIG2a signaling and increased hepatic glycogenesis by regulating Akt2/Foxo1 signaling. Collectively, these data demonstrate that in DIO mice, BCAAs supplementation resulted in serious hepatic metabolic disorder and severe liver insulin resistance: insulin failed to not only suppress gluconeogenesis but also activate lipogenesis. Intervening BCAA metabolism is a potential therapeutic target for severe insulin-resistant disease.<br>


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