scholarly journals Role of Epigallocatechin Gallate in Glucose, Lipid, and Protein Metabolism and L-Theanine in the Metabolism-Regulatory Effects of Epigallocatechin Gallate

Nutrients ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 4120
Author(s):  
Ling Lin ◽  
Li Zeng ◽  
An Liu ◽  
Dongyin Yuan ◽  
Yingqi Peng ◽  
...  
Keyword(s):  
Protein Synthesis ◽  
Insulin Receptor ◽  
Protein Metabolism ◽  
Glycogen Synthase ◽  
Mammalian Target Of Rapamycin ◽  
Epigallocatechin Gallate ◽  
Control Group ◽  
Nutrient Metabolism ◽  
Regulatory Effects

Epigallocatechin gallate (EGCG) and L-theanine (LTA) are important bioactive components in tea that have shown promising effects on nutrient metabolism. However, whether EGCG alone or combined with LTA can regulate the glucose, lipid, and protein metabolism of healthy rats remains unclear. Therefore, we treated healthy rats with EGCG or the combination of EGCG and LTA (EGCG+LTA) to investigate the effects of EGCG on nutrient metabolism and the role of LTA in the metabolism-regulatory effects of EGCG. The results showed that compared with the control group, EGCG activated insulin and AMP-activated protein kinase (AMPK) signals, thus regulating glucose, lipid, and protein metabolism. Compared with EGCG, EGCG+LTA enhanced hepatic and muscle glycogen levels and suppressed phosphorylation of AMPK, glycogen synthase 2, mammalian target of rapamycin, and ribosomal protein S6 kinase. In addition, EGCG+LTA inhibited the expression of liver kinase B1, insulin receptor and insulin receptor substrate, and promoted the phosphorylation level of acetyl-CoA carboxylase. Furthermore, both EGCG and EGCG+LTA were harmless for young rats. In conclusion, EGCG activated AMPK and insulin pathways, thereby promoting glycolysis, glycogen, and protein synthesis and inhibiting fatty acid (FA) and cholesterol synthesis. However, LTA cooperated with EGCG to promote glycogen metabolism and suppressed the effect EGCG on FA and protein synthesis via AMPK signals.

MOLECULAR ASPECTS OF SARCOPENIA PATHOGENESIS IN CHRONOC KIDNEY DISEASE: INTEGRATED ROLE OF mTOR

2018 ◽  
Vol 22 (5) ◽  
pp. 9-16 ◽  
Author(s):  
M. Z. Gasanov
Keyword(s):  
Kidney Disease ◽  
Muscle Mass ◽  
Protein Metabolism ◽  
Mammalian Target Of Rapamycin ◽  
Healthy Person ◽  
Scientific Review ◽  
Cytoskeleton Organization ◽  
Molecular Aspects ◽  
End Stage

In recent decades, the main pathogenetic mechanisms for maintaining muscle mass and strength have been discovered. Most of the scientific papers on the molecular aspects of the  pathogenesis of sarcopenia were focused on the Akt-signaling  pathway. The subject of the study were people of elderly and senile  age, immobilized patients, patients with CKD 1-4 stages, animals. However, recently more attention has been paid to the role  of protein – the mammalian target of rapamycin mTOR. It seems to be a key link in the control of muscle mass and is a promising  marker in understanding the mechanisms of the pathogenesis of  sarcopenia. Its importance in protein metabolism in patients with  end stage kidney disease is not studied and requires further research. The presented scientific review contains  information on the role of mTOR and its components – mTORC1 and mTORC2 in maintaining muscle mass and strength in a healthy  person and in the formation of sarcopenia in patients with CKD. The  general aid of mTORC1 complex is regulation of protein production  which is necessary for cell growth and differentiation. mTORC2  complex functions are not enough studied. It is established that it  plays important role in such biological processes as cytoskeleton  organization, intracellular homeostasis maintaining, so it provides  cell resistance and cell survivability in negative external and internal  impulses. mTOR protein can be considered as promising molecular  marker in diagnostics of protein metabolism early disturbances in  patients with CKD and also as additory factor of sarcopenia severity assessment.

Pentoxifylline decreases body weight loss and muscle protein wasting characteristics of sepsis

1993 ◽  
Vol 265 (4) ◽  
pp. E660-E666 ◽  
Author(s):  
D. Breuille ◽  
M. C. Farge ◽  
F. Rose ◽  
M. Arnal ◽  
D. Attaix ◽  
...  
Keyword(s):  
Body Weight ◽  
Protein Synthesis ◽  
Acute Phase ◽  
Protein Metabolism ◽  
Muscle Wasting ◽  
Acute Phase Protein ◽  
Muscle Protein ◽  
Liver Protein ◽  
Phase Protein

Sepsis induces metabolic disorders that include loss of body weight, muscle wasting, and acute-phase protein synthesis in liver. Cytokines are generally recognized as active mediators of these disorders, and the implication of tumor necrosis factor (TNF) has been frequently discussed in the recent past. However, the identity of the active agent in alterations of protein metabolism is still controversial. To improve our understanding of the role of cytokines in mediating muscle wasting observed in sepsis, we investigated muscle and liver protein metabolism in the following three groups of rats: infected control rats (INF-C); infected rats pretreated with pentoxifylline (PTX-INF), which is a potent inhibitor of TNF secretion; and pair-fed rats for the PTX-INF group pretreated with pentoxifylline. Pentoxifylline nearly completely suppressed TNF secretion but did not influence the transient fall in rectal temperature, the decreased hematocrit, and the increased liver protein mass and synthesis observed in INF-C rats. Pentoxifylline decreased the anorexia, the loss of body weight and muscle protein observed in INF-C animals, and partially prevented the decrease in muscle protein synthesis induced by infection. The overall data indicate that pentoxifylline is an effective agent in mitigating the characteristic muscle protein wasting induced by sepsis and confirm the limited role of TNF in the mediation of the acute-phase protein synthesis. Our results suggest a probable implication of TNF in the regulation of protein balance in muscle but do not allow discarding possible implication of other mediators that would be inhibited by pentoxifylline.

scholarly journals Possible Role of Butyrylcholinesterase in Fat Loss and Decreases in Inflammatory Levels in Patients with Multiple Sclerosis after Treatment with Epigallocatechin Gallate and Coconut Oil: A Pilot Study

Nutrients ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 3230
Author(s):  
Jose Enrique de la Rubia Ortí ◽  
Jose Luis Platero ◽  
Iván Hu Yang ◽  
Jose Joaquin Ceron ◽  
Asta Tvarijonaviciute ◽  
...  
Keyword(s):  
Multiple Sclerosis ◽  
Pilot Study ◽  
Body Fat ◽  
Ketone Bodies ◽  
Intervention Group ◽  
Epigallocatechin Gallate ◽  
Coconut Oil ◽  
Control Group ◽  
Fat Percentage

(1) Background. Multiple sclerosis (MS) is characterised by the loss of muscle throughout the course of the disease, which in many cases is accompanied by obesity and related to inflammation. Nonetheless, consuming epigallocatechin gallate (EGCG) and ketone bodies (especially β-hydroxybutyrate (βHB)) produced after metabolising coconut oil, have exhibited anti-inflammatory effects and a decrease in body fat. In addition, butyrylcholinesterase (BuChE), seems to be related to the pathogenesis of the disease associated with inflammation, and serum concentrations have been related to lipid metabolism. Objective. The aim of the study was to determine the role of BuChE in the changes caused after treatment with EGCG and ketone bodies on the levels of body fat and inflammation state in MS patients. (2) Methods. A pilot study was conducted for 4 months with 51 MS patients who were randomly divided into an intervention group and a control group. The intervention group received 800 mg of EGCG and 60 mL of coconut oil, and the control group was prescribed a placebo. Fat percentage and concentrations of the butyrylcholinesterase enzyme (BuChE), paraoxonase 1 (PON1) activity, triglycerides, interleukin 6 (IL-6), albumin and βHB in serum were measured. (3) Results. The intervention group exhibited significant decreases in IL-6 and fat percentage and significant increases in BuChE, βHB, PON1, albumin and functional capacity (determined by the Expanded Disability Status Scale (EDSS)). On the other hand, the control group only exhibited a decrease in IL-6. After the intervention, BuChE was positively correlated with the activity of PON1, fat percentage and triglycerides in the intervention group, whereas these correlations were not observed in the control group (4). Conclusions. BuChE seems to have an important role in lipolytic activity and the inflammation state in MS patients, evidenced after administering EGCG and coconut oil as a βHB source.

scholarly journals The regulatory domain of protein kinase C delta positively regulates insulin receptor signaling

2009 ◽  
Vol 44 (3) ◽  
pp. 155-169 ◽  
Author(s):  
Avraham I Jacob ◽  
Miriam Horovitz-Fried ◽  
Shlomit Aga-Mizrachi ◽  
Tamar Brutman-Barazani ◽  
Hana Okhrimenko ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Protein Kinase C ◽  
Protein Kinase ◽  
Insulin Receptor ◽  
Glycogen Synthase ◽  
Regulatory Domain ◽  
Protein Kinase C Delta ◽  
Kinase C ◽  
Regulatory Effects ◽  
In Cells

Protein kinase C delta (PKCδ) is induced by insulin to rapidly associate with insulin receptor (IR) and upregulates insulin signaling. We utilized specific JM and CT receptor domains and chimeras of PKCα and PKCδ regulatory and catalytic domains to elucidate which components of PKCδ are responsible for positive regulatory effects of PKCδ on IR signaling. Studies were performed on L6 and L8 skeletal muscle myoblasts and myotubes. PKCδ was preferentially bound to the JM domain of IR, and insulin stimulation increased this binding. Both PKCδ/α and PKCα/δ chimeras (regulatory/catalytic) were bound preferentially to the JM but not to the CT domain of IR. Although IR–PKCδ binding was higher in cells expressing either the PKCδ/α or PKCα/δ chimera than in control cells, upregulation of IR signaling was observed only in PKCδ/α cells. Thus, in response to insulin increases in tyrosine phosphorylation of IR and insulin receptor substrate-1, downstream signaling to protein kinase B and glycogen synthase kinase 3 (GSK3) and glucose uptake were greater in cells overexpressing PKCδ/α and the PKCδ/δ domains than in cells expressing the PKCα/δ domains. Basal binding of Src to PKCδ was higher in both PKCδ/α- and PKCα/δ-expressing cells compared to control. Binding of Src to IR was decreased in PKCα/δ cells but remained elevated in the PKCδ/α cells in response to insulin. Finally, insulin increased Src activity in PKCδ/α-expressing cells but decreased it in PKCα/δ-expressing cells. Thus, the regulatory domain of PKCδ via interaction with Src appears to determine the role of PKCδ as a positive regulator of IR signaling in skeletal muscle.

Visualization of insulin receptors on mouse pre-embryos

1991 ◽  
Vol 3 (1) ◽  
pp. 9 ◽  
Author(s):  
MB Harvey ◽  
PL Kaye
Keyword(s):  
Protein Synthesis ◽  
Insulin Receptor ◽  
Protein Metabolism ◽  
Insulin Receptors ◽  
Mouse Embryos ◽  
Cell Populations ◽  
Mouse Embryogenesis ◽  
Functional Studies ◽  
Early Mouse ◽  
Regulatory Actions

Because insulin stimulates pre-embryonic protein metabolism and growth, the presence of insulin receptors on early mouse embryos was investigated immunohistochemically, using a specific anti-insulin receptor IgG. Staining was not present on fertilized eggs or on 2-cell, 4-cell or uncompacted 8-cell embryos, but insulin receptors were visible on compacting 8-cell embryos and on morulae and blastocysts. This ontogeny correlates with functional studies showing that insulin affects protein synthesis during these post-compaction stages. Insulin receptors were also present on isolated inner cell masses, which have also been shown to be responsive to insulin. Because the ontogeny of the appearance of insulin receptors and the presence of these receptors on both cell populations in the blastocyst coincide with the stimulatory effects of insulin observed in previously reported functional studies on pre-embryos, we believe that these insulin receptors mediate insulin's regulatory actions during early mouse embryogenesis.

scholarly journals The effect of a high dose of 3-hydroxy-3-methylbutyrate on protein metabolism in growing lambs

1997 ◽  
Vol 77 (6) ◽  
pp. 885-896 ◽  
Author(s):  
Isabelle Papet ◽  
Piotr Ostaszewski ◽  
Francoise Glomot ◽  
Christiane Obled ◽  
Magali Faure ◽  
...  
Keyword(s):  
Protein Synthesis ◽  
Amino Acid ◽  
Free Amino Acid ◽  
Protein Metabolism ◽  
Free Amino ◽  
Skeletal Muscles ◽  
Whole Body ◽  
Control Group ◽  
High Dose ◽  
Body Protein

AbstractThe effect of a high dose of 3-hydroxy-3-methylbutyrate (HMB, a leucine catabolite) on protein metabolism was investigated in growing male lambs fed on hay and concentrate. Concentrate was supplemented with either Ca(HMB)2 (4g/kg) or Ca(C03)2 in experimental (HMB) and control groups respectively. Both groups consisted of six 2-month old lambs. Three complementary methods to study protein metabolism were carried out consecutively 2·5 months after beginning the dietary treatment: whole body phenylalanine fluxes, postprandial plasma free amino acid time course and fractional rates of protein synthesis in skeletal muscles. Feeding a high dose of HMB led to a significant increase in some plasma free amino acids compared with controls. Total, oxidative and non-oxidative phenylalanine fluxes were not modified by dietary HMB supplementation. Similarly, an acute infusion of HMB, in the control group, did not change these fluxes. In skeletal muscles, fractional rates of protein synthesis were not affected by long-term dietary supplementation with HMB. Taken together our results showed that administration of a high dose of HMB to lambs was able to modify plasma free amino acid pattern without any effect on whole-body protein turnover and skeletal muscle protein synthesis

scholarly journals Caffeine modulates phosphorylation of insulin receptor substrate-1 and impairs insulin signal transduction in rat skeletal muscle

2011 ◽  
Vol 111 (6) ◽  
pp. 1629-1636 ◽  
Author(s):  
Tatsuro Egawa ◽  
Satoshi Tsuda ◽  
Xiao Ma ◽  
Taku Hamada ◽  
Tatsuya Hayashi
Keyword(s):  
Skeletal Muscle ◽  
Insulin Receptor ◽  
Insulin Signaling ◽  
Kinase Inhibitor ◽  
Glycogen Synthase ◽  
Mammalian Target Of Rapamycin ◽  
Insulin Receptor Substrate ◽  
Dependent Manner ◽  
Insulin Signal Transduction ◽  
Physiological Dose

Caffeine decreases insulin sensitivity and insulin-stimulated glucose transport in skeletal muscle; however, the precise mechanism responsible for this deleterious effect is not understood fully. We investigated the effects of incubation with caffeine on insulin signaling in rat epitrochlearis muscle. Caffeine (≥1 mM, ≥15 min) suppressed insulin-stimulated insulin receptor substrate (IRS)-1 Tyr612 phosphorylation in a dose- and time-dependent manner. These responses were associated with inhibition of the insulin-stimulated phosphorylation of phosphatidylinositol 3-kinase (PI3K) Tyr458, Akt Ser473, and glycogen synthase kinase-3β Ser9 and with inhibition of insulin-stimulated 3- O-methyl-d-glucose (3MG) transport but not with inhibition of the phosphorylation of insulin receptor-β Tyr1158/62/63. Furthermore, caffeine enhanced phosphorylation of IRS-1 Ser307 and an IRS-1 Ser307 kinase, inhibitor-κB kinase (IKK)-α/β Ser176/180. Blockade of IKK/IRS-1 Ser307 by caffeic acid ameliorated the caffeine-induced downregulation of IRS-1 Tyr612 phosphorylation and 3MG transport. Caffeine also increased the phosphorylation of IRS-1 Ser789 and an IRS-1 Ser789 kinase, 5′-AMP-activated protein kinase (AMPK). However, inhibition of IRS-1 Ser789 and AMPK phosphorylation by dantrolene did not rescue the caffeine-induced downregulation of IRS-1 Tyr612 phosphorylation or 3MG transport. In addition, caffeine suppressed the phosphorylation of insulin-stimulated IRS-1 Ser636/639 and upstream kinases, including the mammalian target of rapamycin and p70S6 kinase. Intravenous injection of caffeine at a physiological dose (5 mg/kg) in rats inhibited the phosphorylation of insulin-stimulated IRS-1 Tyr612 and Akt Ser473 in epitrochlearis muscle. Our results indicate that caffeine inhibits insulin signaling partly through the IKK/IRS-1 Ser307 pathway, via a Ca2+- and AMPK-independent mechanism in skeletal muscle.

Renal arginine and protein synthesis are increased during early endotoxemia in mice

2002 ◽  
Vol 282 (2) ◽  
pp. F316-F323 ◽  
Author(s):  
Marcella M. Hallemeesch ◽  
Peter B. Soeters ◽  
Nicolaas E. P. Deutz
Keyword(s):  
Nitric Oxide ◽  
Protein Synthesis ◽  
Protein Metabolism ◽  
De Novo ◽  
Early Response ◽  
No Production ◽  
Arginine Metabolism ◽  
First Time ◽  
Adaptive Role

The kidney has an important function in arginine metabolism, because the kidney is the main endogenous source for de novo arginine production from circulating citrulline. In conditions such as sepsis, nitric oxide (NO) production is increased and is dependent on extracellular arginine availability. To elucidate the adaptive role of renal de novo arginine synthesis in a condition of increased NO production, we studied renal arginine metabolism in a mouse model of endotoxemia. Because arginine flux is largely dependent on protein flux, we also measured protein metabolism in mice. Female mice were injected intraperitoneally with lipopolysaccharide; control mice received 0.9% NaCl. Six hours later, renal blood flow was measured with the use of para-aminohippuric acid. Arginine and protein metabolism were studied using organ-balance, stable-isotope techniques. Systemic NO production was increased in the endotoxin-treated mice. In addition, renal protein synthesis and de novo arginine production from citrulline were increased. However, no effect on renal NO production was observed. In conclusion, increased renal de novo arginine production may serve to sustain systemic NO production. To our knowledge, it was shown for the first time that renal protein synthesis is enhanced in the early response to endotoxemia.

Regulation of protein synthesis by insulin

2006 ◽  
Vol 34 (2) ◽  
pp. 213-216 ◽  
Author(s):  
C.G. Proud
Keyword(s):  
Protein Synthesis ◽  
Translation Initiation ◽  
Ribosomal Proteins ◽  
Glycogen Synthase ◽  
Mammalian Target Of Rapamycin ◽  
Protein Translation ◽  
Initiation Factor ◽  
Translational Machinery ◽  
Phosphoinositide 3 Kinase ◽  
Eef2 Kinase

Insulin rapidly activates protein synthesis by activating components of the translational machinery including eIFs (eukaryotic initiation factors) and eEFs (eukaryotic elongation factors). In the long term, insulin also increases the cellular content of ribosomes to augment the capacity for protein synthesis. The rapid activation of protein synthesis by insulin is mediated primarily through phosphoinositide 3-kinase. This involves the activation of PKB (protein kinase B). In one case, PKB acts to phosphorylate and inactivate glycogen synthase kinase 3, which in turn phosphorylates and inhibits eIF2B. Insulin elicits the dephosphorylation and activation of eIF2B. Since eIF2B is required for recycling of eIF2, a factor required for all cytoplasmic translation initiation events, this will contribute to overall activation of protein synthesis. PKB also phosphorylates the TSC1 (tuberous sclerosis complex 1)–TSC2 complex to relieve its inhibitory action on the mTOR (mammalian target of rapamycin). Inhibition of mTOR by rapamycin markedly impairs insulin-activated protein synthesis. mTOR controls translation initiation and elongation. The cap-binding factor eIF4E can be sequestered in inactive complexes by 4E-BP1 (eIF4E-binding protein 1). Insulin elicits phosphorylation of 4E-BP1 and its release from eIF4E, allowing eIF4E to form initiation factor complexes. Insulin induces dephosphorylation and activation of eEF2 to accelerate elongation. Both effects are blocked by rapamycin. Insulin inactivates eEF2 kinase by increasing its phosphorylation at several mTOR-regulated sites. Insulin also stimulates synthesis of ribosomal proteins by promoting recruitment of their mRNAs into polyribosomes. This is inhibited by rapamycin. Several key questions remain about, for example, the mechanisms by which mTOR controls 4E-BP1 and eEF2 kinase and the control of ribosomal protein translation.

scholarly journals Effect of cinnamon on blood sugar and anthropometric measurement in type two diabetes patients

Bionatura ◽  
2021 ◽  
Vol 6 (4) ◽  
pp. 2280-2283
Author(s):  
Alaa Moyasser Sadiq ◽  
Najah Salman Abid ◽  
Ola Hussein Jasim ◽  
Besmah Mohammed Ali Mohammed Ali
Keyword(s):  
Waist Circumference ◽  
Insulin Receptor ◽  
Blood Sugar ◽  
Glycogen Synthase ◽  
Intervention Group ◽  
Type Ii Diabetes Mellitus ◽  
Biologically Active ◽  
Anthropometric Measurement ◽  
Control Group ◽  
Sugar Levels

There is some emerging evidence that suggests certain supplements help lower blood sugar levels. One of these is cinnamon, which exhibits characteristics that mimic insulin, such as the activity of biologically active substances to activate insulin receptor kinase, increasing glucose uptake, autophosphorylation of the insulin receptor, and glycogen synthase activity. To assess the effect of the cinnamon substance on lowering fasting blood sugar, modifying body weight, body mass index (B.M.I.), and waist circumference in type two diabetics. A randomized controlled intervention clinical trial. The study was conducted on 60 patients with type II diabetes mellitus; the study followed both gender patients for four weeks. The contributors were allocated randomly into a group that receives 2 g/d cinnamon substance (intervention group), and a group without cinnamon substance is given (control group). Fasting plasma glucose (F.P.G.) and anthropometrics measurement at the beginning (beforehand cinnamon supplementation and 4week at the end of the study duration). After 4 weeks of cinnamon taken, serum F.P.G. levels significantly improved (P≤0.0001). Anthropometric measurements (weight, height, B.M.I.) were reduced significantly (change mean ≤ P=0.001) for all. The Present study disclosed that supplementation of 2 gm cinnamon improves F.P.G. and has a good role in anthropometric indices (weight, waist circumference, B.M.I.).

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