Logo Medical Science Monitor Basic Research

Call: 1.631.470.9640
Mon-Fri 10 am - 2 pm EST

Contact Us

Logo Medical Science Monitor Basic Research Logo Medical Science Monitor Basic Research Logo Medical Science Monitor Basic Research

01 March 2018 : Laboratory Research  

Glutamine Enhances the Hypoglycemic Effect of Insulin in L6 Cells via Phosphatidylinositol-3-Kinase (PI3K)/Protein Kinase B (AKT)/Glucose Transporter 4 (GLUT4) Signaling Pathway

Caijuan Wang1ADE, Yujiao Deng1BC, Yenan Yue1BDF, Wenting Chen1BCF, Yu Zhang1BF, Guifang Shi1CF, Zhongming Wu1ADG*

DOI: 10.12659/MSM.909011

Med Sci Monit 2018; 24: LBR1241-1250

Abstract

BACKGROUND: Diabetes mellitus (DM) is characterized by a decreased blood level of glutamine (Gln), which may contribute to the disturbance in the effect of insulin on skeletal muscle. Therefore, it is crucial to study how to improve the effect of insulin on skeletal muscle by increasing Gln. In the present study, we investigated the effect of Gln on the hypoglycemic action of insulin in skeletal muscle L6 cells at high glucose levels through the insulin signaling pathway and glycogen synthesis pathway.

MATERIAL AND METHODS: The L6 cells were cultured in and stimulated by Gln and insulin. The glutamine analogue, L-Gamma-Glutamyl-p-nitroanilide (GPNA), was used for verifying the effect of Gln. The expression of insulin signaling molecules, including phosphatidylinositol-3-kinase (PI3K), 3-phosphoinositide-dependent protein kinase-1 (PDK1), protein kinase B (AKT), protein kinase C zeta (PKCz), and glucose transporter 4 (GLUT4), were detected by real-time PCR and Western blot analysis, GLUT4 translocation was observed by immunofluorescence staining, glycogen synthase kinase (GSK) was analyzed by Western blotting, and glucose uptake was measured by glucose oxidase method (GOD).

RESULTS: The results demonstrated that Gln combined with insulin remarkably up-regulated PI3K and PDK1 and also increased AKT and PKCz phosphorylation. The present study shows that Gln enhanced the impact of insulin on GLUT4 and its translocation. The results of glucose uptake and GSK phosphorylation further confirmed the hypoglycemic effect of Gln accompanied with insulin. The hypoglycemic effect of Gln was reversed by GPNA.

CONCLUSIONS: These findings suggest that Gln enhances the hypoglycemic role of insulin through the PI3K/AKT/GLUT4 signaling pathway and glycogen synthesis pathway.

Keywords: Glucose Metabolism Disorders, Glutamine, Insulin

Comments

Most Viewed Current Articles

13 Apr 2020 : Original article  

Outcome of 24 Weeks of Combined Schroth and Pilates Exercises on Cobb Angle, Angle of Trunk Rotation, Chest...

DOI :10.12659/MSMBR.920449

Med Sci Monit Basic Res 2020; 26:e920449

11 May 2020 : Original article  

Analysis of Psychological and Sleep Status and Exercise Rehabilitation of Front-Line Clinical Staff in the ...

DOI :10.12659/MSMBR.924085

Med Sci Monit Basic Res 2020; 26:e924085

05 Jan 2021 : Review article  

A Southeast Asian Perspective on the COVID-19 Pandemic: Hemoglobin E (HbE)-Trait Confers Resistance Against...

DOI :10.12659/MSMBR.929207

Med Sci Monit Basic Res 2021; 27:e929207

10 Aug 2020 : Clinical Research  

Effects of Cognitive Task Training on Dynamic Balance and Gait of Patients with Stroke: A Preliminary Rando...

DOI :10.12659/MSMBR.925264

Med Sci Monit Basic Res 2020; 26:e925264

Your Privacy

We use cookies to ensure the functionality of our website, to personalize content and advertising, to provide social media features, and to analyze our traffic. If you allow us to do so, we also inform our social media, advertising and analysis partners about your use of our website, You can decise for yourself which categories you you want to deny or allow. Please note that based on your settings not all functionalities of the site are available. View our privacy policy.

Medical Science Monitor Basic Research eISSN: 2325-4416
Medical Science Monitor Basic Research eISSN: 2325-4416