Bozic J, Markotic A, Cikes-Culic V, Novak A, Borovac JA, Vucemilovic H, Trgo G, Ticinovic Kurir T. Ganglioside GM3 content in skeletal muscles is increased in type 2 but decreased in type 1 diabetes rat models: Implications of glycosphingolipid metabolism in pathophysiology of diabetes.
J Diabetes 2018;
10:130-139. [PMID:
28544772 DOI:
10.1111/1753-0407.12569]
[Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/03/2017] [Revised: 03/10/2017] [Accepted: 04/13/2017] [Indexed: 12/15/2022] Open
Abstract
BACKGROUND
Ganglioside GM3 is found in the plasma membrane, where its accumulation attenuates insulin receptor signaling. Considering the role of skeletal muscles in insulin-stimulated glucose uptake, the aim of the present study was to determine the expression of GM3 and its precursors in skeletal muscles of rat models of type 1 and type 2 diabetes mellitus (T1DM and T2DM, respectively).
METHODS
Diabetes was induced in male Sprague-Dawley rats by streptozotocin injection (55 mg/kg, i.p., for T1DM induction; 35 mg/kg, i.p., for T2DM induction), followed by feeding of rats with either a normal pellet diet (T1DM) or a high-fat diet (T2DM). Rats were killed 2 weeks after diabetes induction and samples of skeletal muscle were collected. Frozen quadriceps muscle sections were stained with a primary antibody against GM3 (Neu5Ac) and visualized using a secondary antibody coupled with Texas Red. The muscle content of ganglioside GM3 and its precursors was analyzed by high-performance thin-layer chromatography (HPTLC) followed by GM3 immunostaining.
RESULTS
Muscle GM3 content was significantly higher in T2DM compared with control rats (P < 0.001). Furthermore, levels of the GM3 precursors ceramide, glucosylceramide, and lactosylceramide were significantly higher in T2DM compared with control rats (P < 0.05), whereas ceramide content was significantly lower in T1DM rats (P < 0.05). The intensity of the GM3 band on HPTLC was significantly higher in T2DM rats (P < 0.001) and significantly lower in T1DM rats (P < 0.05) compared with control.
CONCLUSIONS
The expression patterns of GM3 ganglioside and its precursors in diabetic rats suggest that the role of glycosphingolipid metabolism may differ between T2DM and T1DM.
Collapse