Effects of Microbial Metabolites of (−)-Epigallocatechin Gallate on Glucose Uptake in L6 Skeletal Muscle Cell and Glucose Tolerance in ICR Mice

Abstract Reduced glucose uptake into the skeletal muscle is an important pathophysiological abnormality in type 2 diabetes, and is caused by impaired translocation of glucose transporter 4 (GLUT4) to the skeletal muscle cell surface. We found a novel xanthene compound, DS20060511, which induces GLUT4 translocation to the skeletal muscle cell surface, thereby stimulating glucose uptake into the skeletal muscle. DS20060511 induced GLUT4 translocation and glucose uptake into differentiated L6-miytubes and into the skeletal muscles of live mice. These effects were completely abolished in GLUT4 knockout mice. Induction of GLUT4 surface translocation by DS20060511 was independent of the insulin signaling pathways including IRS1-Akt-AS160 phosphorylation and IRS1-Rac1-actin polymerization, eNOS pathway and AMPK pathway. Acute and chronic DS20060511 treatment attenuated the glucose intolerance in obese diabetic mice. Taken together, DS20060511 acts as a skeletal muscle specific-GLUT4 translocation enhancer to facilitate glucose utilization. Further studies with DS20060511 would help to develop a novel antidiabetic medicine.

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Pharmacological activation of AMPK and glucose uptake in cultured human skeletal muscle cells from patients with ME/CFS

Bioscience Reports ◽

10.1042/bsr20180242 ◽

2018 ◽

Vol 38 (3) ◽

Cited By ~ 8

Author(s):

Audrey E. Brown ◽

Beth Dibnah ◽

Emily Fisher ◽

Julia L. Newton ◽

Mark Walker

Keyword(s):

Skeletal Muscle ◽

Glucose Uptake ◽

Muscle Cell ◽

Cell Cultures ◽

Human Skeletal Muscle ◽

Muscle Cells ◽

Skeletal Muscle Cell ◽

Ampk Activation ◽

Atp Content ◽

Human Skeletal Muscle Cells

Skeletal muscle fatigue and post-exertional malaise are key symptoms of myalgic encephalomyelitis (ME)/chronic fatigue syndrome (ME/CFS). We have previously shown that AMP-activated protein kinase (AMPK) activation and glucose uptake are impaired in primary human skeletal muscle cell cultures derived from patients with ME/CFS in response to electrical pulse stimulation (EPS), a method which induces contraction of muscle cells in vitro. The aim of the present study was to assess if AMPK could be activated pharmacologically in ME/CFS. Primary skeletal muscle cell cultures from patients with ME/CFS and healthy controls were treated with either metformin or compound 991. AMPK activation was assessed by Western blot and glucose uptake measured. Both metformin and 991 treatment significantly increased AMPK activation and glucose uptake in muscle cell cultures from both controls and ME/CFS. Cellular ATP content was unaffected by treatment although ATP content was significantly decreased in ME/CFS compared with controls. Pharmacological activation of AMPK can improve glucose uptake in muscle cell cultures from patients with ME/CFS. This suggests that the failure of EPS to activate AMPK in these muscle cultures is due to a defect proximal to AMPK. Further work is required to delineate the defect and determine whether pharmacological activation of AMPK improves muscle function in patients with ME/CFS.

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