Branched-chain Amino Acids Diet Research Articles

Abstract 14967: Branching Out: Disrupted Branched Chain Amino Acid Metabolism Exacerbates Pulmonary Arterial Hypertension

Introduction: Valine, leucine, and isoleucine are essential branched chain amino acids (BCAA), and recent epidemiological studies report elevated BCAAs predict worse outcomes in several cardiovascular diseases with metabolic origins such as diabetes, heart failure, and hypertension. However, the role of BCAA metabolism in pulmonary arterial hypertension pathophysiology is relatively unexplored. Hypothesis: BCAAs are elevated in human PAH and reduction of BCAAs via small molecule activation of BCAA catabolism and dietary interventions combats PAH severity in preclinical PAH. Methods: Literature search of human PAH metabolomics studies was conducted. For rodent studies, male Sprague Dawley rats were divided into three groups: control (saline injection), monocrotaline (MCT) vehicle (MCT-V), or MCT-BT2, a small molecule inducer of BCAA catabolism. BT2 was administered at 20mg/kg/day. A low BCAA dietary intervention was implemented, with male Sprague Dawley rats divided into two groups: MCT-standard chow diet and MCT-low BCAA diet. To assess exercise capacity, rodents underwent a maximal exercise testing protocol before echocardiographic and hemodynamic assessments of PAH. Proteomic analysis of lung mitochondrial extracts was performed to define the molecular effects of BT2. Results: Of 11 studies evaluating human PAH metabolomics, 7 studies reported elevated BCAAs or BCAA metabolites in PAH. BT2 treatment improved exercise performance, reduced PA pressures, and augmented RV function. Moreover, the MCT-BT2 group possessed a distinct lung proteomic signature with changes in inflammatory and metabolic pathways. Finally, the low BCAA diet intervention modestly combatted PAH severity. Conclusions: BCAA metabolism is disrupted in human PAH and interventions that reduce circulating BCAAs display therapeutic potential in rodent PAH.

Branched-chain amino acids promote thrombocytopoiesis by activating mTOR signaling

BackgroundMegakaryocyte differentiation and platelet production disorders are the main causes of thrombocythemia and thrombocytopenia and lead to thrombosis or hemorrhage. Branched-chain amino acids (BCAAs) are essential nutrients that regulate important metabolic signals. BCAA administration could also increase platelet activation and promote the risk of thrombosis. ObjectivesTo unveil the role of BCAAs in thrombocytopoiesis. MethodsBCAA-fed mice and megakaryocyte/platelet-specific branched-chain α-keto acid dehydrogenase E1α subunit-deficient mice were used to study the role of BCAAs in thrombocytopoiesis. ResultsIn this study, we found that BCAA diet could facilitate megakaryocyte differentiation and platelet production. Meanwhile, megakaryocyte/platelet-specific branched-chain α-keto acid dehydrogenase E1α subunit-deficient mice developed thrombocythemia, which was mainly caused by the excessive differentiation of megakaryocytes and proplatelet biogenesis. Moreover, the use of BT2, the agonist of BCAA catabolism, could affect proplatelet formation (PPF) and megakaryocyte polyploidization, as well as ameliorating the thrombocythemia of BCAA-fed mice. ConclusionWe found that deficiency in BCAA catabolism led to the activation of p70S6K/mammalian target of rapamycin (mTOR) signaling, megakaryocyte over differentiation, and the acceleration of PPF. Activating BCAA metabolism with BT2 could inhibit mTOR signaling, reduce PPF, and ameliorate thrombocythemia in BCAA-fed mice. Therefore, this study reveals a novel role of BCAAs in megakaryocyte differentiation and platelet production, suggesting that targeting BCAA-mediated p70S6K/mTOR signaling may be a potential strategy for the treatment of thrombocytopenia or thrombocythemia.

Nutritional management and branched-chain amino acids diet among patients undergoing living donor liver transplantation

Nutritional management and branched-chain amino acids diet among patients undergoing living donor liver transplantation

Role of gut microbiota-derived branched-chain amino acids in the pathogenesis of Parkinson’s disease: An animal study

Neuroinflammation caused by the disorder of gut microbiota and its metabolites is associated with the pathogenesis of Parkinson's disease (PD). Thus, it is necessary to identify certain molecules derived from gut microbiota to verify whether they could become intervention targets for the treatment of PD. The branched-chain amino acids (BCAAs), as a common dietary supplement, could modulate brain function. Herein, we investigated the longitudinal shifts of microbial community in mice treated with rotenone for 0, 3 and 4 weeks by 16S rRNA gene sequencing to identify the microbial markers at different PD stages. Serum BCAAs were determined by gas chromatography-mass spectrometry. Then, rotenone-induced mice were given a high BCAA diet to evaluate the motor and non-motor functions, dopaminergic neuron loss, and inflammation levels. Using a PD mouse model, we discovered that during PD progression, the alterations of gut microbiota compositions led to the peripheral decrease of BCAAs. Based on the serum lipopolysaccharide binding protein concentrations and the levels of pro-inflammatory factors (including tumor necrosis factor-α, interleukin [IL]-1β, and IL-6) in the colon and substantia nigra, we found that the high BCAA diet could attenuate the inflammatory levels in PD mice, and reverse motor and non-motor dysfunctions and dopaminergic neuron impairment. Together, our results emphasize the dynamic changes of gut microbiota and BCAA metabolism and propose a novel strategy for PD therapy: a high BCAA diet intervention could improve PD progression by regulating the levels of inflammation.

Elevated BCAA Suppresses the Development and Metastasis of Breast Cancer.

Branched-chain amino acids (BCAAs) are the three essential amino acids including leucine, isoleucine, and valine. BCAA metabolism has been linked with the development of a variety of tumors. However, the impact of dietary BCAA intake on breast tumor progression and metastasis remains to be fully explored. Here, we unexpectedly find that the elevated BCAA, either in the genetic model or via increasing dietary intake in mice, suppresses the tumor growth and lung metastasis of breast cancer. The survival analysis shows that BCAA catabolic gene expression is strongly associated with long-term oncological outcomes in patients with breast cancer. In Pp2cm knockout mice in which BCAAs accumulate due to the genetic defect of BCAA catabolism, the breast tumor growth is suppressed. Interestingly, while the cell proliferation and tumor vasculature remain unaffected, more cell death occurs in the tumor in Pp2cm knockout mice, accompanied with increased natural killer (NK) cells. Importantly, increasing BCAA dietary intake suppresses breast tumor growth in mice. On the other hand, there are fewer lung metastases from primary breast tumor in Pp2cm knockout mice and the high BCAA diet-fed mice, suggesting high BCAA also suppresses the lung metastasis of breast cancer. Furthermore, low BCAA diet promotes lung colonization of breast cancer cells in tail vein model. The migration and invasion abilities of breast cancer cells are impaired by high concentration of BCAA in culture medium. The suppressed tumor metastasis and cell migration/invasion abilities by elevated BCAA are accompanied with reduced N-cadherin expression. Together, these data show high BCAA suppresses both tumor growth and metastasis of breast cancer, demonstrating the potential benefits of increasing BCAA dietary intake in the treatment of breast cancer.

Effects of maternal branched-chain amino acid and alanine supplementation on growth and biomarkers of protein metabolism in dams fed a low-protein diet and their offspring.

A considerable number of studies have reported that maternal protein restriction may disturb fetal growth and organ development due to a lower availability of amino acids. Leucine, one of branched-chain amino acid (BCAA) promotes protein synthesis through mechanistic target of rapamycin signaling. Here, we investigated the effects of BCAA supplementation in the dams fed a low-protein diet on serum and hepatic biochemical parameters of protein metabolism of dams and their offspring. Female ICR mice were fed a control (20% casein), a low-protein (10% casein), a low-protein with 2% BCAAs or a low-protein with 2% alanine diet for 2 weeks before mating and then throughout pregnancy and lactation. Alanine was used as an amino nitrogen control for the BCAA. Dams and their male offspring were sacrificed at postnatal day 21. There were no changes in body weight and fat mass in low-protein fed dams; however, BCAA supplementation significantly increased fat mass and serum leptin levels. Low-protein diet consumption reduced maternal protein synthesis based on biochemical analysis of serum albumin and hepatic protein levels and immunoblotting of S6 protein, which were increased by BCAA and alanine supplementation. Offspring from dams fed a low-protein diet exhibited lower body and organ weights. Body weight and hepatic protein levels of the offspring were increased by alanine supplementation. However, the decreased serum biochemical parameters, including glucose, triglyceride, total protein and albumin levels in the low-protein offspring group were not changed in response to BCAA or alanine supplementation. A reduced density of the hepatic vessel system in the offspring from dams fed a low-protein diet was restored in the offspring from dams fed either BCAA and alanine-supplemented diet. These results suggest that supplementation of amino nitrogen per se may be responsible for inducing hepatic protein synthesis in the dams fed a low-protein diet and alleviating the distorted growth and liver development of their offspring.

The RNA-binding protein LARP1 is dispensable for pancreatic β-cell function and mass

Mechanistic target of rapamycin complex 1 (mTORC1) deficiency or chronic hyperactivation in pancreatic β-cells leads to diabetes. mTORC1 complexes with La-related protein 1 (LARP1) to specifically regulate the expression of 5′ terminal oligopyrimidine tract (5′TOP) mRNAs which encode proteins of the translation machinery and ribosome biogenesis. Here we show that LARP1 is the most expressed LARP in mouse islets and human β-cells, being 2–4-fold more abundant than LARP1B, a member of the family that also interacts with mTORC1. Interestingly, β-cells from diabetic patients have higher LARP1 and LARP1B expression. However, specific deletion of Larp1 gene in β-cells (β-Larp1KO mice) did not impair insulin secretion and glucose metabolism in male and female mice. High fat or high branched-chain amino acid (BCAA) diets did not disturb glucose homeostasis compared to control littermates up to 8 weeks; BCAA diet slightly impaired glucose tolerance in the β-Larp1KO mice at 16 weeks. However, no differences in plasma insulin levels, non-fasting glycemia and β-cell mass were observed in the β-Larp1KO mice. In conclusion, LARP1 is the most abundant LARP in mouse islets and human β-cells, and it is upregulated in diabetic subjects. However, genetically disruption of Larp1 gene did not impact glucose homeostasis in basal and diabetogenic conditions, suggesting no major role for LARP1 in β-cells.

Dietary branched-chain amino acid assessment in broilers from 22 to 35\u2009days of age

BackgroundValine and isoleucine are similar in chemical structure and their limitation in broiler chicken diets. To evaluate their limitation and interactive effects, multivariate assessment nutrition studies for the branched-chain amino acids (BCAA) are needed. A three level (− 1, 0, + 1), three-factor Box-Behnken design study was conducted to assess dietary BCAA ratios to lysine of 65, 75, and 85 for valine, 58, 66, and 74 for isoleucine, and 110, 130, and 150 for leucine in male and female Lohman Indian River broilers from 22 to 35 d of age.ResultsLive performance of male broilers was not affected by BCAA level. However, male broilers fed increasing isoleucine had improved (P = 0.07) carcass yield as leucine and valine were reduced. Female broilers had improved body weight gain (P = 0.05) and feed conversion (P = 0.003) when leucine and isoleucine were at their lowest levels, independent of valine, but increasing leucine impaired live performance and warranted concomitant increases in isoleucine to restore responses. Increasing dietary isoleucine and valine in female broilers increased breast meat yield (P = 0.05), but increasing leucine tended to diminish the response.ConclusionThe female Lohman Indian River broiler is more sensitive to BCAA diet manipulation than males. Specifically, as dietary leucine is increased in female broilers, dietary isoleucine increases were needed to offset the negative effects. Both increases in dietary valine and isoleucine improved breast meat yield in female broilers, but only when birds were fed the lowest dietary leucine.

1869-P: Elevated Maternal BCAAs during Gestation and Lactation Reprograms Offspring’s Glucose Regulation

Maternal nutrition impacts neonate development and can have long-lasting physiological effects. Newborns from obese and type 2 diabetes (T2D) mothers are at a higher risk of developing metabolic deficits later in life. Women with gestational diabetes (GD) or T2D often have elevated serum branched chain amino acids (BCAAs), one of the most accurate predictors of insulin resistance (IR) in adults. Since BCAAs are actively taken up by the placenta, fetuses are exposed to elevation of BCAAs in their mothers. Additionally, newborns can be exposed to high BCAA levels via breast milk or formula feeding. Interestingly, BCAAs levels are higher in breast milk from obese mothers and some infant formulas have higher BCAA content than average breast milk. However, the direct impact of BCAA overnutrition in utero and early postnatal life on newborn predisposition to obesity and T2D is poorly understood. To investigate the effects of exposure to high BCAA levels during gestation and postnatally, we fed female mice during pregnancy and lactation two different isocaloric diets with equal total protein content, but one of the diets enriched in BCAAs. Their offsprings was weaned onto normal or high fat (HFD) diets and evaluated for changes in body composition and systemic metabolic regulation over a six-month period. We found that maternal BCAA supplementation triggered hyperglycemia and impaired insulin secretion in newborns. Progeny from mothers fed the high BCAA diet exhibited elevated fasting glucose levels, reduced insulin secretion, and striking reductions in glucose tolerance and insulin sensitivity, which were exacerbated by HFD supplementation. These findings suggest that early exposure to BCAA overnutrition has a strong dysregulating effect on systemic glucose metabolism. We will provide insights into the molecular underpinnings at play. Disclosure J. Tzeng: None. A. Aguillard: None. D. Lorenzo: None. Funding American Diabetes Association (1-19-JDF-081 to D.L.); National Institute of Diabetes and Digestive and Kidney Diseases (DK072476-15225-UNC01)

SAT-611 Dietary Reduction of Branched-Chain Amino Acids

Background: One of the primary risk factors for the development of diabetes is obesity. Although moderate weight loss can lead to improvements in metabolic health, reduced-calorie diets are difficult to sustain. A number of groups have shown that low protein diets are associated with metabolic health in both rodents and humans. In particular, the branched-chain amino acids (BCAAs) leucine, isoleucine, and valine are associated with insulin resistance and diabetes in humans. Blood levels of the BCAAs decrease in humans fed a low protein diet, and we recently showed that reducing either dietary BCAAs or protein rapidly restored normal body composition and insulin sensitivity to diet-induced obese mice without reducing calorie intake. We are determining the effect of a low BCAA diet in humans with prediabetes and overweight/obesity. Objectives: The primary outcome is the reduction of dietary BCAA intake by at least 50% in subjects in the low BCAA group while maintaining overall baseline calories. Secondary outcomes are compliance and tolerability of the low BCAA protein powder. Method: This is a randomized, controlled, single-blind pilot study. The intervention arm uses a low BCAA protein powder to replace two meals per day for 60 days. The control arm uses a control protein powder with standard amounts of amino acids to replace two meals per day for 60 days. We are enrolling 16 males with the following criteria: ages 35 to 65, BMI 28 to 35, and hemoglobin A1c 5.7%-6.4% or fasting glucose 101-125 mg/dL. A registered dietitian reviews a 4-day food diary prior to diet initiation and creates an individualized meal plan based on those values in order to maintain baseline calories during the study diet. Baseline measurements prior to diet initiation include waist circumference, body mass index, fasting insulin and glucose, an oral glucose tolerance test, resting metabolic rate, body composition testing using dual energy x-ray absorptiometry, jumping mechanography to assess muscle function, and a stool sample to assess the microbiome. These tests are repeated after 60 days on the diet. Safety labs are performed while on the diet and 2-3 weeks after the end of the diet. Weekly safety telephone calls occur while on the diet. The food diaries are repeated after 30 and 60 days on the diet. Results/Conclusion: Ten of sixteen subjects have completed the trial to date. One out of four subjects in the low BCAA group dropped out; the remainder successfully completed the study. BCAA intake was successfully reduced by 50%. Missed beverages were uncommon. No significant safety concerns or side effects have been noted. In conclusion, our early results suggest that replacement of two meals a day with a protein powder lacking BCAA for up to two months is a safe and feasible intervention. Ongoing analysis will determine if this intervention impacts metabolic health.

Differential Impact of Dietary Branched Chain and Aromatic Amino Acids on Chronic Kidney Disease Progression in Rats.

The metabolism of dietary proteins generates waste products that are excreted by the kidney, in particular nitrogen-containing urea, uric acid, ammonia, creatinine, and other metabolites such as phosphates, sulfates, and protons. Kidney adaptation includes an increase in renal plasma flow (RPF) and glomerular filtration rate (GFR) and represents a burden for diseased kidneys increasing the progression rate of CKD. The present study aimed at identifying potential differences between amino acid (AA) groups constituting dietary proteins regarding their impact on RPF, GFR, and CKD progression. We utilized the well-established 5/6 nephrectomy (5/6 Nx) CKD model in rats and submitted the animals for 5 weeks to either the control diet (18% casein protein) or to diets containing 8% casein supplemented with 10% of a mix of free amino acids, representing all or only a subset of the amino acids contained in casein. Whereas the RPF and GFR measured in free moving animals remained stable during the course of the diet in rats receiving the control mix, these parameters decreased in animals receiving the branched chain amino acid (BCAA) supplementation and increased in the ones receiving the aromatic amino acids (AAAs). In animals receiving essential amino acids (EAAs) containing both BCAAs and AAAs, there was only a small increase in RPF. The kidneys of the 5/6 Nx rats receiving the BCAA diet showed the strongest increase in smooth muscle actin and collagen mRNA expression as a result of higher level of inflammation and fibrosis. These animals receiving BCAAs also showed an increase in plasma free fatty acids pointing to a problem at the level of energy metabolism. In contrast, the animals under AAA diet showed an activation of AMPK and STAT3. Taken together, our results demonstrate that subsets of EAAs contained in dietary proteins, specifically BCAAs and AAAs, exert contrasting effects on kidney functional parameters and CKD progression.

533-P: Association of Serum Branched-Chain Amino Acids with Kidney Function Decline in Type 2 Diabetes: The Hong Kong Diabetes Register

Background: There are recent claims that high dietary BCAA may improve insulin resistance although this conflicts with the recommendation that low protein/BCAA diet may confer renoprotection in patients with chronic kidney disease (CKD) stages 3-5. Type 2 diabetes (T2D) has dysregulated energy metabolism where excessive BCAA intake can be harmful. We examined the risk association of BCAA and rate of estimated glomerular filtration rate (eGFR) decline in a prospective T2D cohort. Method: We measured serum BCAA in 2340 adults with CKD stages 1-2 at baseline with available stored sera. By using linear regression analysis, we examined the association of serum BCAA with annual change in eGFR, which was estimated from a linear mixed model using at least three eGFR measurements from baseline until the onset of CKD or data censored on June 2017. Results: In this study cohort with mean±SD follow-up of 10.0±5.3 years (age 55.2±11.2 years, BMI 25.4±4.3 kg/m2, HbA1c 7.6±1.7%, annual change in eGFR -1.37±1.28 ml/min/1.73m2), patients with incident CKD had higher serum BCAA (median [IQR]: 622.7 [540.3-730] vs. 595.8 [518.3-680.3] µM; P<0.001) and usage of blood pressure (BP)-lowering drugs (56.2% vs. 33.7%; P<0.001) at baseline than those without CKD. Every doubling of serum BCAA was associated with faster eGFR decline (β -0.24 [95% CI -0.34, -0.14]; P<0.001) that remained significant after adjusting for age, sex and diabetes duration (β -0.27 [-0.37, -0.18]; P<0.001). The effect was attenuated by further adjustment of HbA1c, BMI, lipids, BP and related drug usage (β -0.16 [-0.27, -0.05]; P=0.003), as well as by retinopathy, albuminuria and eGFR at baseline (β -0.13 [-0.23, -0.02]; P=0.016). There was no significant BCAA-sex interaction. Conclusions: In Chinese T2D patients with CKD stages 1-2, high serum BCAA was independently associated with a modest decline in eGFR, suggesting the renoprotective effect of a low BCAA diet may be extended to early CKD with careful monitoring. Disclosure L. Lim: Research Support; Self; AstraZeneca. Speaker's Bureau; Self; Boehringer Ingelheim Pharmaceuticals, Inc., Merck & Co., Inc. E.S. Lau: None. H. Lee: None. C.H. Tam: None. C.K. Lim: None. A. Luk: None. E. Chow: Research Support; Self; Powder Pharmaceuticals Inc., Sanofi-Aventis. R.C. Ma: Advisory Panel; Self; Boehringer Ingelheim International GmbH. Research Support; Self; AstraZeneca, Bayer AG, Pfizer Inc. Stock/Shareholder; Self; GemVCare. Other Relationship; Self; AstraZeneca. J.C. Chan: Board Member; Self; Asia Diabetes Foundation. Consultant; Self; AstraZeneca, Boehringer Ingelheim Pharmaceuticals, Inc., Lilly Diabetes, Medtronic, Merck Sharp & Dohme Corp., Sanofi-Aventis. Research Support; Self; Amgen Inc., AstraZeneca, Lee Powder, Lilly Diabetes, Pfizer Inc., Sanofi-Aventis. Speaker's Bureau; Self; Ascensia Diabetes Care. Stock/Shareholder; Self; GemVCare. A.P. Kong: Advisory Panel; Self; Lilly Diabetes. Research Support; Self; AstraZeneca, Lilly Diabetes. Speaker's Bureau; Self; Abbott. Other Relationship; Self; AstraZeneca, Novartis Pharmaceuticals Corporation, Sanofi. Funding Hong Kong Society of Endocrinology, Metabolism and Reproduction; Hong Kong Association for the Study of Obesity

Effect of branched chain amino acid on apoptosis of neurons after focal cerebral ischemia in rats

Objective To investigate the regulatory effect of branched chain amino acids(BCAA) on the expression of apoptosis related proteins after cerebral ischemia reperfusion injury and the protective effects of BCAA on ischemic brain injury in rats. Methods 40 male SD rats were randomly divided into normal diet group(n=20)and branched chain amino acid (BCAA) group(n=20)according to the random number table, and each group was randomly divided into control group (n=6), sham operation group (n=6) and model group (n=8) which used suture method to make ischemia reperfusion model. After modeling, modified Neurological Severity Scores (mNSS) was used to access the neurological impairment degree of 2, 6, 24, 48 and 72 h in each group. The expression of apoptosis related proteins (Cleaved, Bax/Bcl-2) after 72 h was detected by the method of immune protein imprinting (Caspase3) and compared between normal diet group and BCAA group. Results Compared with the normal diet rats, the mNSS of BCAA diet rats after modeling at 2, 6, 24, 48, 72 h decreased(11.35±2.78 vs. 7.15±2.41, P=0.019; 9.35±1.75 vs. 5.82±1.17, P=0.002; 6.11±1.16 vs. 4.39±1.46, P=0.048; 5.87±1.32 vs. 3.55±1.94, P=0.036; 4.98±2.24 vs. 2.09±1.33, P=0.022). The expression of cleaved caspase3 protein and the ratio of Bax/Bcl-2 decreased in BCAA group. Conclusion BCAA can alleviate the apoptosis of rats after ischemia and reperfusion, reduce the damage of nerve function, and has a positive protective effect on ischemic brain injury. Key words: Branched chain amino acid; Cerebral ischemia reperfusion; Apoptosis

Branched chain amino acids impact health and lifespan indirectly via amino acid balance and appetite control.

Elevated branched chain amino acids (BCAAs) are associated with obesity and insulin resistance. How long-term dietary BCAAs impact late-life health and lifespan is unknown. Here, we show that when dietary BCAAs are varied against a fixed, isocaloric macronutrient background, long-term exposure to high BCAA diets leads to hyperphagia, obesity and reduced lifespan. These effects are not due to elevated BCAA per se or hepatic mTOR activation, but rather due to a shift in the relative quantity of dietary BCAAs and other AAs, notably tryptophan and threonine. Increasing the ratio of BCAAs to these AAs resulted in hyperphagia and is associated with central serotonin depletion. Preventing hyperphagia by calorie restriction or pair-feeding averts the health costs of a high BCAA diet. Our data highlight a role for amino acid quality in energy balance and show that health costs of chronic high BCAA intakes need not be due to intrinsic toxicity but, rather, a consequence of hyperphagia driven by AA imbalance.

Dietary Amino Acids Affect the Rate of Chronic Kidney Disease Progression in Rats

The population affected by CKD continues to increase but the mechanisms by which proteins/amino acids lead to an increase in the Glomerular Filtration Rate (GFR) and kidney function deterioration are not well understood. Our study aims to unravel the differential impact that specific groups of amino acids might have on the progression of Chronic Kidney Disease. We utilized the well‐established 5/6th Nephrectomy (5/6th Nx) model to induce CKD. 5/6th Nx Wistar Han rats were randomly divided into groups receiving either the control diet (18% casein protein, n=10) or one of different diets, in each case containing 8% protein supplemented with 10% of a mix of free amino acids (AAs): Essential‐ (EAAs), Non‐Essential‐(NEAAs), Branched Chain‐ (BCAAs), Aromatic‐ (AAAs), or all AAs in the same proportion as in the protein mix (8+10). In addition to this, we also had a group that was fed a diet containing 18% protein supplemented with 1.82% L‐arginine. Both GFR and RPF were measured in free moving animals, GFR transcutaneously using FITC‐sinistrin, and RPF by using radiolabelled para‐aminohippurate (PAH).Our results show that none of the modified diets caused any decrease in body weight, food and water consumption in the different groups up to 9 weeks after surgery. However, the pace of RPF and GFR alteration was diet‐dependent. Animals receiving AAAs and EAAs showed the slowest progression, whereas the most dramatic reduction was in case of the animals on the BCAA diet (from 1.5 +/−0.1 ml/min/100g BW to 0.55 +/− 0.033 ml/min/100g BW). We also tested GFR changes in animals who were on the different diets but did not undergo 5/6th Nx and therefore, had no CKD. These animals showed no decrease in GFR 9 weeks after mock surgery (1.42 +/− 0.11 and 1.42 +/− 0.13 ml/min/100g BW). The kidneys of the BCAAs‐receiving 5/6th Nx rats also showed the strongest increase in smooth muscle actin and collagen mRNA expression, as expected for a higher level of inflammation and fibrosis. The SMA protein levels were increased 2‐fold and the collagen levels more than 3‐fold compared to animals on control diet. Towards deciphering the mechanisms underlying these differential effects of the various amino acids diets on CKD progression, we are testing the activity of various signalling pathways, specifically changes in phospho‐ and total Stat3, Akt and S6k levels. No changes were observed at the protein level (using Western blots, repeated 3 times) for the various diet groups. Taken together, our results show that different amino acid diets given for 9 weeks exert no impact on healthy kidneys, but they suggest that in CKD, high levels of dietary BCAAs exert a deleterious effect on progression, whereas high levels of AAAs surprisingly display a protective effect.Support or Funding InformationThis study is supported by the Swiss National Centre of Competence in Research (NCCR), Kidney Control of Homeostasis (Kidney. CH)This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

Mice deficient in the mitochondrial branched-chain aminotransferase (BCATm) respond with delayed tumour growth to a challenge with EL-4 lymphoma

BackgroundThe mitochondrial branched-chain aminotransferase (BCATm) is a recently discovered cancer marker with a poorly defined role in tumour progression.MethodsTo understand how a loss of function of BCATm affects cancer, the global knockout mouse BCATmKO was challenged with EL-4 lymphoma under different diet compositions with varying amounts of branched-chain amino acids (BCAAs). Next, the growth and metabolism of EL-4 cells were studied in the presence of different leucine concentrations in the growth medium.ResultsBCATmKO mice experienced delayed tumour growth when fed standard rodent chow or a normal BCAA diet. Tumour suppression correlated with 37.6- and 18.9-fold increases in plasma and tumour BCAAs, 37.5% and 30.4% decreases in tumour glutamine and alanine, and a 3.5-fold increase in the phosphorylation of tumour AMPK in BCATmKO mice on standard rodent chow. Similar results were obtained with a normal but not with a choice BCAA diet.ConclusionsGlobal deletion of BCATm caused a dramatic build-up of BCAAs, which could not be utilised for energy or amino acid synthesis, ultimately delaying the growth of lymphoma tumours. Furthermore, physiological, but not high, leucine concentrations promoted the growth of EL-4 cells. BCATm and BCAA metabolism were identified as attractive targets for anti-lymphoma therapy.

PPAR\u03b3/Pgc-1\u03b1-Fndc5 pathway up-regulation in gastrocnemius and heart muscle of exercised, branched chain amino acid diet fed mice

BackgroundPrevious studies have revealed the inductive effect of branched-chain amino acids (BCAAs) catabolism on fatty acid oxidation and metabolism, especially in muscle cells. In the present investigation, we have attempted to address whether a combination of BCAAs supplement consumption with aerobic exercise could elaborate the expression of PPARγ, Pgc-1α and Fndc5 genes in gastrocnemius muscle and heart tissue of male C57BL/6 mice.MethodsThirty-six young male mice with an average weight of 18 ± 2 g were selected. Mice were randomly assigned to 6 groups: 20 mg/mL of BCAAs consumption with simultaneous exercise-training, 60 mg/mL of BCAAs consumption with simultaneous exercise-training, exercise-trained with no BCAAs consumption group, 20 mg/mL BCAAs without exercise-training, 60 mg/mL BCAAs without exercise-training, and untrained mice without BCAAs consumption.ResultsThe findings showed a combination of 20 mg/mL BCAAs with aerobic exercise significantly increased Fndc5, PPARγ, Pgc-1α gene expression in skeletal muscles although, circulating Irisin levels remained unchanged (p < 0.05). Interestingly, plasma urea and lactate levels were significantly increased in 60 mg/mL BCAAs administrated mice which performed exercised (p < 0.05). Two-way analysis of variance (ANOVA) was used to examine significant difference between groups and sedentary group.ConclusionsResults showed inductive effect of 20 mg/mL BCAAs on expression levels of Fndc5, PPARγ, Pgc-1α in gastrocnemius muscle similar with counterparts in heart tissue. Of note, higher serum irisin levels were detected after 20 mg/mL BCAAs supplementation coincided with the exercise.Graphical abstractAn Overview on supplemantaion of branched chain amoinoacids on metablism of skeletal muscle and heart

Branched-Chain Amino Acids Are the Primary Limiting Amino Acids in the Diets of Endurance-Trained Men after a Bout of Prolonged Exercise

The indicator amino acid oxidation (IAAO) method estimates the protein intake required to maximize whole-body protein synthesis and identify the daily protein requirement in a variety of populations. However, it is unclear whether the greater requirements for endurance athletes previously determined by the IAAO reflect an increased demand for all or only some amino acids. The aim of this study was to determine the primary rate-limiting amino acids in endurance-trained athletes after prolonged exercise, by measuring the oxidation of ingested [1-13C]phenylalanine in response to variable amino acid intake. Five endurance-trained men (means ± SDs: age, 26±7 y; body weight, 66.9±9.5 kg; maximal oxygen consumption, 63.3±4.3 mL · kg-1 · min-1) performed 5 trials that involved 2 d of controlled diet (1.4g protein · kg-1 · d-1) and running (10 km on day 1 and 5 km on day 2) prior to performing an acute bout of endurance exercise (20-km treadmill run) on day 3. During recovery on day 3, participants consumed test diets as 8 isocaloric hourly meals providing sufficient energy and carbohydrate but a variable amino acid intake. The test diets, consumed in random order, were deficient (BASE: 0.8g · kg-1 · d-1) and sufficient (SUF; 1.75g · kg-1 · d-1) amino acid diets modeled after egg protein, and BASE supplemented with branched-chain amino acids (BCAA diet; 1.03g · kg-1 · d-1), essential amino acids (EAA diet; 1.23g · kg-1 · d-1), or nonessential amino acids (NEAA diet; 1.75g · kg-1 · d-1). Whole-body phenylalanine flux (Q), 13CO2 excretion (F13CO2), and phenylalanine oxidation (OX) were determined according to standard IAAO methodology. There was no effect of amino acid intake on Q (P=0.43). F13CO2 was significantly (all P<0.01) lower than BASE for the BCAA (∼32%), EAA (∼31%), and SUF (∼36%) diet treatments. F13CO2 for the NEAA diet was ∼18% lower than for BASE (P<0.05) but ∼28% greater than for SUF (P<0.05). OX was similarly decreased (∼24-41%) in all conditions compared with BASE (all P<0.05). Our results suggest that the BCAAs may be the primary rate-liming amino acids in the greater daily protein requirement of endurance trained men. This trial was registered at clinicaltrials.gov as NCT02628249.

Restoration of metabolic health by decreased consumption of branched-chain amino acids.

We recently found that feeding healthy mice a diet with reduced levels of branched-chain amino acids (BCAAs), which are associated with insulin resistance in both humans and rodents, modestly improves glucose tolerance and slows fat mass gain. In the present study, we show that a reduced BCAA diet promotes rapid fat mass loss without calorie restriction in obese mice. Selective reduction of dietary BCAAs also restores glucose tolerance and insulin sensitivity to obese mice, even as they continue to consume a high-fat, high-sugar diet. A low BCAA diet transiently induces FGF21 (fibroblast growth factor 21) and increases energy expenditure. We suggest that dietary protein quality (i.e. the precise macronutrient composition of dietary protein) may impact the effectiveness of weight loss diets. Obesity and diabetes are increasing problems around the world, and although even moderate weight loss can improve metabolic health, reduced calorie diets are notoriously difficult to sustain. Branched-chain amino acids (BCAAs; leucine, isoleucine and valine) are elevated in the blood of obese, insulin-resistant humans and rodents. We recently demonstrated that specifically reducing dietary levels of BCAAs has beneficial effects on the metabolic health of young, growing mice, improving glucose tolerance and modestly slowing fat mass gain. In the present study, we examine the hypothesis that reducing dietary BCAAs will promote weight loss, reduce adiposity, and improve blood glucose control in diet-induced obese mice with pre-existing metabolic syndrome. We find that specifically reducing dietary BCAAs rapidly reverses diet-induced obesity and improves glucoregulatory control in diet-induced obese mice. Most dramatically, mice eating an otherwise unhealthy high-calorie, high-sugar Western diet with reduced levels of BCAAs lost weight and fat mass rapidly until regaining a normal weight. Importantly, this normalization of weight was mediated not by caloric restriction or increased activity, but by increased energy expenditure, and was accompanied by a transient induction of the energy balance regulating hormone FGF21 (fibroblast growth factor 21). Consumption of a Western diet reduced in BCAAs was also accompanied by a dramatic improvement in glucose tolerance and insulin resistance. Our results link dietary BCAAs with the regulation of metabolic health and energy balance in obese animals, and suggest that specifically reducing dietary BCAAs may represent a highly translatable option for the treatment of obesity and insulin resistance.

Perinatal western-type diet and associated gestational weight gain alter postpartum maternal mood.

IntroductionThe role of perinatal diet in postpartum maternal mood disorders, including depression and anxiety, remains unclear. We investigated whether perinatal consumption of a Western‐type diet (high in fat and branched‐chain amino acids [BCAA]) and associated gestational weight gain (GWG) cause serotonin dysregulation in the central nervous system (CNS), resulting in postpartum depression and anxiety (PPD/A).MethodsMouse dams were fed one of four diets (high‐fat/high BCAA, low‐fat/high BCAA, high‐fat, and low‐fat) prior to mating and throughout gestation and lactation. Postpartum behavioral assessments were conducted, and plasma and brain tissues assayed. To evaluate potential clinical utility, we conducted preliminary human studies using data from an extant sample of 17 primiparous women with high GWG, comparing across self‐reported postpartum mood symptoms using the Edinburgh Postnatal Depression Scale (EPDS) for percent GWG and plasma amino acid levels.ResultsMouse dams fed the high‐fat/high BCAA diet gained more weight per kcal consumed, and BCAA‐supplemented dams lost weight more slowly postpartum. Dams on BCAA‐supplemented diets exhibited increased PPD/A‐like behavior, decreased dopaminergic function, and decreased plasma tyrosine and histidine levels when assessed on postnatal day (P)8. Preliminary human data showed that GWG accounted for 29% of the variance in EPDS scores. Histidine was also lower in women with higher EPDS scores.ConclusionsThese findings highlight the role of perinatal diet and excess GWG in the development of postpartum mood disorders.