Selenium-enriched exopolysaccharides improve skeletal muscle glucose uptake of diabetic KKAy mice via AMPK pathway

Abstract

Selenium-enriched exopolysaccharides (EPS) produced by Enterobacter cloacae Z0206 have been proven to possess effect on reducing blood glucose level in diabetic mice. To investigate the specific mechanism, we studied the effects of oral supply with EPS on skeletal muscle glucose transportation and consumption in high-fat-diet-induced diabetic KKAy mice. We found that EPS supplementation increased expressions of glucose transporter 4 (Glut4), hexokinase 2 (hk2), phosphorylation of AMP-activated kinase subunit α2 (pAMPKα2), and peroxisome proliferator-activated receptor γ coactivator 1α (PGC-1α), and increased expression of characteristic protein of oxidative fibers such as troponin I and cytochrome c (Cytc). Furthermore, we found that EPS increased glucose uptake and expressions of pAMPKα2 and PGC-1α in palmitic acid (PA)-induced C2C12 cells. However, while EPS inhibited AMPKα2 with interference RNA (iRNA), effects of EPS on the improvement of glucose uptake diminished. These results indicated that EPS may improve skeletal muscle glucose uptake of diabetic KKAy mice through AMPKα2-PGC-1α pathway.

Serine is required for the maintenance of redox balance and proliferation in the intestine under oxidative stress

“…ATP, ADP, and AMP concentrations in IPEC‐J2 cells were determined by HPLC as previously described . In brief, IPEC‐J2 cell samples were dissolved in 1 mL of 8% perchloric acid for 30 minutes in ice.…”

“…concentration ATP, ADP, and AMP concentrations in IPEC-J2 cells were determined by HPLC as previously described. 25 In brief, IPEC-J2 cell samples were dissolved in 1 mL of 8% perchloric acid for 30 minutes in ice. After centrifugation at 12 000 rpm for 15 minutes at 4°C, the supernatant was neutralized with 3 M K 2 CO 3 for 10 minutes in ice and then centrifuged at 1800 rpm for 10 minutes at 4°C to remove KClO 4 .…”

Enhanced antioxidant activity, antibacterial activity and hypoglycemic effect of luteolin by complexation with manganese(ii) and its inhibition kinetics on xanthine oxidase

“…of diabetes mellitus. 40,41 It has been proven that skeletal muscle was the main site of insulin-stimulated glucose uptake in vivo and impaired skeletal muscle glucose was the dominating reason leading to the increase of blood glucose in the pathogenesis of insulin resistance and type two diabetes, as glucose transport is the rate-limiting step in muscle glucose metabolism. 28,42,43 However, liver is the primary organ and liver cells become resistant rst for metabolism of glucose, resulting in impaired glycogen synthesis and failure to suppress the production of glucose.…”

Role of adenosine 5'-monophosphate-activated protein kinase inα-linolenic acid-induced intestinal lipid metabolism

“…Total RNA was extracted with the TRIzol reagent (Invitrogen) and then complementary DNA was synthesised with RevertAid Reverse Transcriptase (Fermentas). Real-time PCR was performed according to the method used previously ( 22 ) . Briefly, the PCR system consisted of 10 µl of SYBR Premix Ex Taq (2×) mix (Roche), 0·4 µl of ROX (50×) (Roche), 1·0 µl of cDNA, 7·8 µl of double-distilled water and 0·4 µl of primer pairs (10 m m ), all in a total volume of 20 µl.…”

“…Total RNA was extracted with the TRIzol reagent (Invitrogen) and then complementary DNA was synthesised with RevertAid Reverse Transcriptase (Fermentas). Real-time PCR was performed according to the method used previously (22) . Briefly, the PCR system consisted of 10 µl of SYBR Premix Ex Taq .…”