scholarly journals Branched-Chain Amino Acid Supplementation Alters the Abundance of Mechanistic Target of Rapamycin and Insulin Signaling Proteins in Subcutaneous Adipose Explants from Lactating Holstein Cows

Animals ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 2714
Author(s):  
Yusheng Liang ◽  
Fabiana F. Cardoso ◽  
Claudia Parys ◽  
Felipe C. Cardoso ◽  
Juan J. Loor

The objective of this study was to investigate changes in protein abundance of mTOR and insulin signaling pathway components along with amino acid (AA) transporters in bovine s.c. adipose (SAT) explants in response to increased supply of Leu, Ile, or Val. Explants of SAT from four lactating Holstein cows were incubated with high-glucose serum-free DMEM, to which the 10 essential AAs were added to create the following treatments: ideal mix of essential AA (IPAA; Lys:Met 2.9:1; Lys:Thr 1.8:1; Lys:His 2.38:1; Lys:Val 1.23:1; Lys:Ile 1.45:1; Lys:Leu 0.85:1; Lys:Arg 2.08:1) or IPAA supplemented with Ile, Val, or Leu to achieve a Lys:Ile of 1.29:1 (incIle), Lys:Val 1.12:1 (incVal), or Lys:Leu (incLeu) 0.78:1 for 4 h. Compared with IPAA, incLeu or incIle led to greater activation of protein kinase B (AKT; p-AKT/total AKT) and mTOR (p-mTOR/total mTOR). Total EAA in media averaged 7.8 ± 0.06 mmol/L across treatments. Incubation with incLeu, incIle, or incVal led to greater protein abundance of solute carrier family 38 member 1 (SLC38A1), a Gln transporter, and the BCAA catabolism enzyme branched-chain α-keto acid dehydrogenase kinase (BCKDK) compared with IPAA. Activation of eukaryotic elongation factor 2 (eEF2; p-eEF2/total eEF2) was also greater in response to incLeu, incIle, or incVal. Furthermore, compared with incLeu or incIle, incVal supplementation led to greater abundance of SLC38A1 and BCKDK. BCKDK is a rate-limiting enzyme regulating BCAA catabolism via inactivation and phosphorylation of the BCKD complex. Overall, data suggested that enhanced individual supplementation of BCAA activates mTOR and insulin signaling in SAT. Increased AA transport into tissue and lower BCAA catabolism could be part of the mechanism driving these responses. The potential practical applications for enhancing post-ruminal supply of BCAA via feeding in rumen-protected form support in vivo studies to ascertain the role of these AAs on adipose tissue biology.

Animals ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 2114
Author(s):  
Yusheng Liang ◽  
Nana Ma ◽  
Danielle N. Coleman ◽  
Fang Liu ◽  
Yu Li ◽  
...  

The objective was to perform a proof-of-principle study to evaluate the effects of methionine (Met) and arginine (Arg) supply on protein abundance of amino acid, insulin signaling, and glutathione metabolism-related proteins in subcutaneous adipose tissue (SAT) explants under ceramide (Ce) challenge. SAT from four lactating Holstein cows was incubated with one of the following media: ideal profile of amino acid as the control (IPAA; Lys:Met 2.9:1, Lys:Arg 2:1), increased Met (incMet; Lys:Met 2.5:1), increased Arg (incArg; Lys:Arg 1:1), or incMet plus incArg (Lys:Met 2.5:1 Lys:Arg 1:1) with or without 100 μM exogenous cell-permeable Ce (N-Acetyl-d-sphingosine). Ceramide stimulation downregulated the overall abundance of phosphorylated (p) protein kinase B (AKT), p-mechanistic target of rapamycin (mTOR), and p-eukaryotic elongation factor 2 (eEF2). Without Ce stimulation, increased Met, Arg, or Met + Arg resulted in lower p-mTOR. Compared with control SAT stimulated with Ce, increased Met, Arg, or Met + Arg resulted in greater activation of mTOR (p-mTOR/total mTOR) and AKT (p-AKT/total AKT), with a more pronounced response due to Arg. The greatest protein abundance of glutathione S-transferase Mu 1 (GSTM1) was detected in response to increased Met supply during Ce stimulation. Ceramide stimulation decreased the overall protein abundance of the Na-coupled neutral amino acid transporter SLC38A1 and branched-chain alpha-ketoacid dehydrogenase kinase (BCKDK). However, compared with controls, increased Met or Arg supply attenuated the downregulation of BCKDK induced by Ce. Circulating ceramides might affect amino acid, insulin signaling, and glutathione metabolism in dairy cow adipose tissue. Further in vivo studies are needed to confirm the role of rumen-protected amino acids in regulating bovine adipose function.


Andrologia ◽  
2018 ◽  
Vol 51 (2) ◽  
pp. e13183 ◽  
Author(s):  
Mehrnoosh Bahadorani ◽  
Marziyeh Tavalaee ◽  
Navid Abedpoor ◽  
Kamran Ghaedi ◽  
Mohammad N. Nazem ◽  
...  

1993 ◽  
Vol 74 (6) ◽  
pp. 2711-2717 ◽  
Author(s):  
D. A. MacLean ◽  
T. E. Graham

This study examined the effects of branched-chain amino acid (BCAA) supplementation on amino acid and ammonia (NH3) responses during prolonged exercise in humans. Seven men cycled for 60 min at 75% of maximal O2 uptake after 45 min of either placebo (dextrose, 77 mg/kg) or BCAA (leucine + isoleucine + valine, 77 mg/kg) supplementation. Plasma samples (antecubital vein) were collected at rest and during exercise and analyzed for plasma NH3 and amino acids, whole blood glucose and lactate, and serum free fatty acids and glycerol. After BCAA administration, plasma BCAA levels increased from 375 +/- 22 to 760 +/- 80 microM (P < 0.05) by the onset of exercise and remained elevated throughout the experiment. Plasma NH3 concentrations increased continually during exercise for both trials and were higher (P < 0.05) after BCAA supplementation than after placebo administration. The mean plasma NH3 increase from rest to 60 min was 79 +/- 10 and 53 +/- 4 microM for BCAA and placebo trials, respectively. Plasma alanine and glutamine concentrations were elevated (P < 0.05) during exercise for both treatments. However, only glutamine concentrations were greater (P < 0.05) for BCAA trial than for placebo trial during exercise. There were no significant differences between treatments for glucose, lactate, free fatty acids, and glycerol or any other plasma amino acid. These data suggest that increased BCAA availability before exercise, when initial muscle glycogen is normal, results in significantly greater plasma NH3 responses during exercise than does placebo administration.


2021 ◽  
Vol 53 (8S) ◽  
pp. 283-283
Author(s):  
Jesse T. Peach ◽  
Dakota Funk ◽  
Lizzi Frothingham ◽  
McMilin R. Colleen ◽  
Brian Bothner ◽  
...  

Sign in / Sign up

Export Citation Format

Share Document