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International Journal of Endocrinology
Volume 2014 (2014), Article ID 312452, 9 pages
Research Article

Liraglutide Exerts Antidiabetic Effect via PTP1B and PI3K/Akt2 Signaling Pathway in Skeletal Muscle of KKAy Mice

1College of Medicine, Xi’an Jiaotong University, Xi’an, Shaanxi 710061, China
2Xi’an No. 1 Hospital, Xi’an, Shaanxi 710002, China

Received 17 June 2014; Revised 22 July 2014; Accepted 22 July 2014; Published 11 August 2014

Academic Editor: Khalid Hussain

Copyright © 2014 Wenjun Ji et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


Background. Liraglutide (a glucagon-like peptide 1 analog) was used for the treatment of type 2 diabetes (T2DM) which could produce glucose-dependent insulin secretion. Aim. The aim was to investigate whether liraglutide could improve myofibril and mitochondria injury in skeletal muscle and the mechanisms in diabetic KKAy mice. Method. We divided the male KKAy mice into 2 groups: liraglutide group (250 μg/kg/day liraglutide subcutaneous injection) and model group; meanwhile, the male C57BL/6J mice were considered as the control. After 6 weeks, the ultrastructure of skeletal muscle was observed by electron microscope. The gene expressions of protein tyrosine phosphatase 1B (PTP1B), phosphatidylinositol 3-kinase (PI3K), and glucose transporter type 4 (GLUT4) were determined by real-time PCR. The protein levels of the above molecules and phospho-Akt2 (p-Akt2) were measured by Western blot. Results. Liraglutide significantly ameliorated the injury of mitochondria by increasing the number (+441%) and the area (+113%) of mitochondria and mitochondrial area/100 µm2 (+396%) in skeletal muscle of KKAy mice. The results of real-time PCR and Western blot showed that liraglutide downregulated PTP1B while it upregulated PI3K and GLUT4 (). The protein level of p-Akt2/Akt2 was also increased (). Conclusion. These results revealed that liraglutide could improve myofibril and mitochondria injury in skeletal muscle against T2DM via PTP1B and PI3K/Akt2 signaling pathway.