l-Arginine promotes protein synthesis and cell growth in brown adipocyte precursor cells via the mTOR signal pathway

Abstract

L-Arginine has been reported to enhance brown adipose tissue developments in fetal lambs of obese ewes, but the underlying mechanism is unknown. The present study tested the hypothesis that L-arginine stimulates growth and development of brown adipocyte precursor cells (BAPCs) through activation of mammalian target of rapamycin cell signaling. BAPCs isolated from fetal lambs at day 90 of gestation were incubated for 6 h in arginine-free DMEM, and then cultured in DMEM with concentrations of 50, 100, 200, 500 or 1000 μmol L-arginine/L for 24-96 h. Cell proliferation, protein turnover, the mammalian target of rapamycin (mTOR) signaling pathway and pre-adipocyte differentiation markers were determined. L-arginine treatment enhanced (P < 0.05) BAPC growth and protein synthesis, while inhibiting proteolysis in a dose-dependent manner. Compared with 50 and 100 μmol/L (the concentrations of arginine in the maternal plasma of obese ewes), 200 μmol L-arginine/L (the concentrations of arginine in the maternal plasma of obese ewes receiving arginine supplementation) increased (P < 0.05) the abundances of phosphorylated mTOR, P70 and 4EBP1, as well as the abundances of PGC1α, UCP1, BMP7 and PRDM16. These novel findings indicate that increasing extra-cellular arginine concentration from 50 to 200 µmol/L activates mTOR cell signaling in BAPCs and enhances their growth and development in a dose-dependent manner. Our results provide a mechanism for arginine supplementation to enhance the development of brown adipose tissue in fetal lambs.

Quantitative analysis of amino acids in human and bovine colostrum milk samples through iTRAQ labeling

“…Additionally, we found that arginine (ARG) and GLY content was fivefold higher in bovine colostrum than that in human colostrum. A recent study showed that ARG stimulates the growth and development of fetal brown adipocyte precursor cells by modulating protein turnover, and that l ‐ARG plays a crucial role in the maintenance of human immune function, as well as processes associated with human growth and anti‐aging . Additionally, GLY exhibits multiple functions related to metabolism, growth, immunity, and survival .…”

Hepatoprotective effect of chiisanoside from Acanthopanax sessiliflorus against LPS/D‐GalN‐induced acute liver injury by inhibiting NF‐κB and activating Nrf2/HO‐1 signaling pathways

“…Equal amounts of proteins were separated by 12% sodium dodecyl sulfate / polyacrylamide gel electrophoresis (SDS/PAGE), then transferred onto a PVDF membrane (Roche Diagnostics, Mannheim, Germany) and probed with various primary antibodies (CST, Boston, USA), followed by incubation with a horseradish peroxidase‐conjugated secondary antibody (Thermo Fisher Scientific, Waltham, USA) and chemiluminescence detection. The quantification was normalized with the corresponding value of glyceraldehyde 3‐phosphate dehydrogenase (GAPDH) and lamin B expression …”

Two macamide extracts relieve physical fatigue by attenuating muscle damage in mice

“…Numerous factors are responsible for fatigue during exercise, including glycogen and phosphocreatine depletion, accumulation of metabolites such as blood lactic acid (BLA) and blood urea nitrogen (BUN), as well as homeostasis‐imbalance‐induced muscle damage . Physical fatigue can therefore be alleviated by repairing muscle damage along with elimination of metabolic products accumulated during exercise . The limited variety of anti‐fatigue drugs, and their side effects, have created a need to seek potential alternatives with anti‐fatigue effects, such as traditional herbs and functional foods.…”