scholarly journals Suppression of the mTORC1/STAT3/Notch1 pathway by activated AMPK prevents hepatic insulin resistance induced by excess amino acids

2014 ◽  
Vol 306 (2) ◽  
pp. E197-E209 ◽  
Author(s):  
Hongliang Li ◽  
Jiyeon Lee ◽  
Chaoyong He ◽  
Ming-Hui Zou ◽  
Zhonglin Xie
Keyword(s):  
Insulin Resistance ◽  
Amino Acids ◽  
Amino Acid ◽  
Signaling Pathway ◽  
High Protein Diet ◽  
Chronic Administration ◽  
Hepatic Insulin Resistance ◽  
Notch1 Signaling ◽  
Mtorc1 Signaling ◽  
Notch1 Signaling Pathway

Nutrient overload is associated with the development of obesity, insulin resistance, and type 2 diabetes. However, the underlying mechanisms for developing insulin resistance in the presence of excess nutrients are incompletely understood. We investigated whether activation of AMP-activated protein kinase (AMPK) prevents the hepatic insulin resistance that is induced by the consumption of a high-protein diet (HPD) and the presence of excess amino acids. Exposure of HepG2 cells to excess amino acids reduced AMPK phosphorylation, upregulated Notch1 expression, and impaired the insulin-stimulated phosphorylation of Akt Ser473 and insulin receptor substrate-1 (IRS-1) Tyr612. Inhibition of Notch1 prevented amino acid-induced insulin resistance, which was accompanied by reduced expression of Rbp-Jk, hairy and enhancer of split-1, and forkhead box O1. Mechanistically, mTORC1 signaling was activated by excess amino acids, which then positively regulated Notch1 expression through the activation of the signal transducer and activator of transcription 3 (STAT3). Activation of AMPK by metformin inhibited mTORC1-STAT3 signaling, thereby preventing excess amino acid-impaired insulin signaling. Finally, HPD feeding suppressed AMPK activity, activated mTORC1/STAT3/Notch1 signaling, and induced insulin resistance. Chronic administration of either metformin or rapamycin inhibited the HPD-activated mTORC1/STAT3/Notch1 signaling pathway and prevented hepatic insulin resistance. We conclude that the upregulation of Notch1 expression by hyperactive mTORC1 signaling is an essential event in the development of hepatic insulin resistance in the presence of excess amino acids. Activation of AMPK prevents amino acid-induced insulin resistance through the suppression of the mTORC1/STAT3/Notch1 signaling pathway.

Growth performance, amino acid retention and mRNA levels of mTORC1 signaling pathway genes in Nile tilapia fingerlings fed protein-bound and crystalline amino acids

Aquaculture ◽  
2021 ◽  
pp. 736953
Author(s):  
Thaís Pereira da Cruz ◽  
Mariana Michelato ◽  
Maeli Dal-Pai-Silva ◽  
Tassiana Gutierrez de Paula ◽  
Edson Assunção Macedo ◽  
...  
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Growth Performance ◽  
Signaling Pathway ◽  
Nile Tilapia ◽  
Mrna Levels ◽  
Mtorc1 Signaling ◽  
Crystalline Amino Acids

scholarly journals Oncogene APOL1 promotes proliferation and inhibits apoptosis via activating NOTCH1 signaling pathway in pancreatic cancer

2021 ◽  
Vol 12 (8) ◽  
Author(s):  
Jiewei Lin ◽  
Zhiwei Xu ◽  
Junjie Xie ◽  
Xiaxing Deng ◽  
Lingxi Jiang ◽  
...  
Keyword(s):  
Pancreatic Cancer ◽  
Signaling Pathway ◽  
Density Lipoprotein ◽  
Human Pancreatic Cancer ◽  
Luciferase Reporter ◽  
Notch1 Signaling ◽  
In Vivo Experiments ◽  
Notch1 Signaling Pathway

AbstractAPOL1 encodes a secreted high-density lipoprotein, which has been considered as an aberrantly expressed gene in multiple cancers. Nevertheless, the role of APOL1 in the regulatory mechanisms of pancreatic cancer remains unknown and should be explored. We identified APOL1 was abnormally elevated in human pancreatic cancer tissues compared with that in adjacent tissues and was associated with poor prognosis. The effects of APOL1 in PC cell proliferation, cell cycle, and apoptosis was verified via functional in vitro and in vivo experiments. The results showed that knockdown of APOL1 significantly inhibited the proliferation and promoted apoptosis of pancreatic cancer. In addition, we identified APOL1 could be a regulator of NOTCH1 signaling pathway using bioinformatics tools, qRT-PCR, dual-luciferase reporter assay, and western blotting. In summary, APOL1 could function as an oncogene to promote proliferation and inhibit apoptosis through activating NOTCH1 signaling pathway expression in pancreatic cancer; therefore, it may act as a novel therapeutic target for pancreatic cancer.

scholarly journals Long non-coding RNA TUG1 knockdown hinders the tumorigenesis of multiple myeloma by regulating the microRNA-34a-5p/NOTCH1 signaling pathway

2020 ◽  
Vol 15 (1) ◽  
pp. 284-295
Author(s):  
Yongtian Zhang ◽  
Dandan Zhao ◽  
Shumei Li ◽  
Meng Xiao ◽  
Hongjing Zhou ◽  
...  
Keyword(s):  
Multiple Myeloma ◽  
Signaling Pathway ◽  
Notch Receptor ◽  
Cell Counting ◽  
Luciferase Reporter ◽  
Notch1 Signaling ◽  
Non Coding Rna ◽  
Notch1 Signaling Pathway ◽  
Long Non Coding Rna

AbstractMultiple myeloma (MM) is a serious health issue in hematological malignancies. Long non-coding RNA taurine-upregulated gene 1 (TUG1) has been reported to be highly expressed in the plasma of MM patients. However, the functions of TUG1 in MM tumorigenesis along with related molecular basis are still undefined. In this study, increased TUG1 and decreased microRNA-34a-5p (miR-34a-5p) levels in MM tissues and cells were measured by the real-time quantitative polymerase reaction assay. The expression of relative proteins was determined by the Western blot assay. TUG1 knockdown suppressed cell viability, induced cell cycle arrest and cell apoptosis in MM cells, as shown by Cell Counting Kit-8 and flow cytometry assays. Bioinformatics analysis, luciferase reporter assay, and RNA pull-down assay indicated that miR-34a-5p was a target of TUG1 and directly bound to notch receptor 1 (NOTCH1), and TUG1 regulated the NOTCH1 expression by targeting miR-34a-5p. The functions of miR-34a-5p were abrogated by TUG1 upregulation. Moreover, TUG1 loss impeded MM xenograft tumor growth in vivo by upregulating miR-34a-5p and downregulating NOTCH1. Furthermore, TUG1 depletion inhibited the expression of Hes-1, Survivin, and Bcl-2 protein in MM cells and xenograft tumors. TUG1 knockdown inhibited MM tumorigenesis by regulating the miR-34a-5p/NOTCH1 signaling pathway in vitro and in vivo, deepening our understanding of the TUG1 function in MM.

scholarly journals Feeding diversified protein sources exacerbates hepatic insulin resistance via increased gut microbial branched-chain fatty acids and mTORC1 signaling in obese mice

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Béatrice S.-Y. Choi ◽  
Noëmie Daniel ◽  
Vanessa P. Houde ◽  
Adia Ouellette ◽  
Bruno Marcotte ◽  
...  
Keyword(s):  
Insulin Resistance ◽  
Fatty Acids ◽  
Gut Microbiota ◽  
Protein Source ◽  
Hepatic Insulin Resistance ◽  
Branched Chain Fatty Acids ◽  
Mtorc1 Signaling ◽  
Branched Chain ◽  
Mixed Protein ◽  
Chain Fatty Acids

AbstractAnimal models of human diseases are classically fed purified diets that contain casein as the unique protein source. We show that provision of a mixed protein source mirroring that found in the western diet exacerbates diet-induced obesity and insulin resistance by potentiating hepatic mTORC1/S6K1 signaling as compared to casein alone. These effects involve alterations in gut microbiota as shown by fecal microbiota transplantation studies. The detrimental impact of the mixed protein source is also linked with early changes in microbial production of branched-chain fatty acids (BCFA) and elevated plasma and hepatic acylcarnitines, indicative of aberrant mitochondrial fatty acid oxidation. We further show that the BCFA, isobutyric and isovaleric acid, increase glucose production and activate mTORC1/S6K1 in hepatocytes. Our findings demonstrate that alteration of dietary protein source exerts a rapid and robust impact on gut microbiota and BCFA with significant consequences for the development of obesity and insulin resistance.

scholarly journals Interleukin-22 attenuates renal tubular cells inflammation and fibrosis induced by TGF-β1 through Notch1 signaling pathway

Renal Failure ◽  
2020 ◽  
Vol 42 (1) ◽  
pp. 381-390 ◽  
Author(s):  
Rong Tang ◽  
Xiangcheng Xiao ◽  
Yang Lu ◽  
Huihui Li ◽  
Qiaoling Zhou ◽  
...  
Keyword(s):  
Signaling Pathway ◽  
Tubular Cells ◽  
Interleukin 22 ◽  
Renal Tubular Cells ◽  
Notch1 Signaling ◽  
Renal Tubular ◽  
Notch1 Signaling Pathway ◽  
Tgf Β1

Effect of protein restriction on15N transfer from dietary [15N]alanine and [15N]Spirulina platensisinto urea

2001 ◽  
Vol 281 (2) ◽  
pp. E349-E356 ◽  
Author(s):  
Mazen J. Hamadeh ◽  
L. John Hoffer
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Test Meal ◽  
High Protein Diet ◽  
Normal Subjects ◽  
Insulin Dependent Diabetes Mellitus ◽  
Protein Restriction ◽  
Dependent Diabetes Mellitus ◽  
Serum Amino Acids ◽  
Normal Men

Six normal men consumed a mixed test meal while adapted to high (1.5 g · kg−1· day−1) and low (0.3 g · kg−1· day−1) protein intakes. They completed this protocol twice: when the test meals included 3 mg/kg of [15N]alanine ([15N]Ala) and when they included 30 mg/kg of intrinsically labeled [15N] Spirulina platensis([15N]SPI). Six subjects with insulin-dependent diabetes mellitus (IDDM) receiving conventional insulin therapy consumed the test meal with added [15N]Ala while adapted to their customary high-protein diet. Protein restriction increased serum alanine, glycine, glutamine, and methionine concentrations and reduced those of leucine. Whether the previous diet was high or low in protein, there was a similar increase in serum alanine, methionine, and branched-chain amino acid concentrations after the test meal and a similar pattern of15N enrichment in serum amino acids for a given tracer. When [15N]Ala was included in the test meal,15N appeared rapidly in serum alanine and glutamine, to a minor degree in leucine and isoleucine, and not at all in other circulating amino acids. With [15N]SPI, there was a slow appearance of the label in all serum amino acids analyzed. Despite the different serum amino acid labeling, protein restriction reduced the postmeal transfer of dietary15N in [15N]Ala or [15N]SPI into [15N]urea by similar amounts (38 and 43%, respectively, not significant). The response of the subjects with IDDM was similar to that of the normal subjects. Information about adaptive reductions in dietary amino acid catabolism obtained by adding [15N]Ala to a test meal appears to be equivalent to that obtained using an intrinsically labeled protein tracer.

scholarly journals Performance of Broilers Fed Low Protein Diets with Lysine and Methionine Supplements

2006 ◽  
Vol 6 (1) ◽  
pp. 47-59
Author(s):  
Nancy Montilla ◽  
◽  
Lolito Bestil ◽  
Sulpecio Bantugan ◽  
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Protein Content ◽  
High Protein Diet ◽  
Protein Diet ◽  
Amino Acid Supplementation ◽  
Feed Conversion ◽  
Broiler Performance ◽  
Acid Supplementation ◽  
Low Protein

A feeding trial with broilers was conducted to evaluate the effects of amino acids (lysine and methionine) supplementation of diets low in protein content on the voluntary intake, feed conversion efficiency, broiler performance, and cost and return of broiler production. Results showed cumulative voluntary feed intake was not significantly affected by lowering the protein content of the diet. Cumulative weight gain of broilers was lower with diet when supplemented iwht lysine and methionine to meet requirements. Birds fed with diets low in protein has less efficient feed converstion, but became comparable with those receiveing diets high in protein when supplemented with amino acids. Feed cost per kilogram broiler produced was not significantly affected by diets used in the study, although the low-protien diet with amino acid supplement had the lowest values. In terms of return above feed and chick cost, broilers fed with high-protein diet had the greatest value, but not significantly different from birds fed with low-protien diet with amino acid supplementation which gave about P10 per bird higher returns than those fed low-protein diet without amino acid supplementation.

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