scholarly journals Effect of resistance exercise under conditions of reduced blood insulin on AMPKα Ser485/491 inhibitory phosphorylation and AMPK pathway activation

2017 ◽  
Vol 313 (2) ◽  
pp. R110-R119 ◽  
Author(s):  
Kohei Kido ◽  
Takumi Yokokawa ◽  
Satoru Ato ◽  
Koji Sato ◽  
Satoshi Fujita
Keyword(s):  
Gene Expression ◽  
Protein Kinase ◽  
Resistance Exercise ◽  
Glucose Uptake ◽  
Akt Pathway ◽  
Insulin Levels ◽  
Blood Insulin ◽  
Ampk Pathway ◽  
Pathway Activation ◽  
Exercise Induced

Insulin stimulates skeletal muscle glucose uptake via activation of the protein kinase B/Akt (Akt) pathway. Recent studies suggest that insulin downregulates AMP-activated protein kinase (AMPK) activity via Ser485/491 phosphorylation of the AMPK α-subunit. Thus lower blood insulin concentrations may induce AMPK signal activation. Acute exercise is one method to stimulate AMPK activation; however, no study has examined the relationship between blood insulin levels and acute resistance exercise-induced AMPK pathway activation. Based on previous findings, we hypothesized that the acute resistance exercise-induced AMPK pathway activation would be augmented by disruptions in insulin secretion through a decrease in AMPKα Ser485/491 inhibitory phosphorylation. To test the hypothesis, 10-wk-old male Sprague-Dawley rats were administered the toxin streptozotocin (STZ; 55 mg/kg) to destroy the insulin secreting β-cells. Three days postinjection, the right gastrocnemius muscle from STZ and control rats was subjected to resistance exercise by percutaneous electrical stimulation. Animals were killed 0, 1, or 3 h later; activation of the Akt/AMPK and downstream pathways in the muscle tissue was analyzed by Western blotting and real-time PCR. Notably, STZ rats showed a significant decrease in basal Akt and AMPKα Ser485/491 phosphorylation, but substantial exercise-induced increases in both AMPKα Thr172 and acetyl-CoA carboxylase (ACC) Ser79 phosphorylation were observed. Although no significant impact on resistance exercise-induced Akt pathway activation or glucose uptake was found, resistance exercise-induced peroxisome proliferator-activated receptor (PPAR)-γ coactivator-1 α (PGC-1α) gene expression was augmented by STZ treatment. Collectively, these data suggest that circulating insulin levels may regulate acute resistance exercise-induced AMPK pathway activation and AMPK-dependent gene expression relating to basal AMPKα Ser485/491 phosphorylation.

scholarly journals Changes in Exercise-Induced Gene Expression in 5'-AMP-Activated Protein Kinase  3-Null and  3 R225Q Transgenic Mice

Diabetes ◽  
2005 ◽  
Vol 54 (12) ◽  
pp. 3484-3489 ◽  
Author(s):  
B. R. Barnes ◽  
Y. C. Long ◽  
T. L. Steiler ◽  
Y. Leng ◽  
D. Galuska ◽  
...  
Keyword(s):  
Gene Expression ◽  
Protein Kinase ◽  
Transgenic Mice ◽  
Exercise Induced ◽  
Amp Activated Protein Kinase

scholarly journals MicroRNA-506 modulates insulin resistance in human adipocytes by targeting S6K1 and altering the IRS1/PI3K/AKT insulin signaling pathway

2021 ◽  
Author(s):  
Feng-Yu Zhong ◽  
Jing Li ◽  
Yu-Mei Wang ◽  
Yao Chen ◽  
Jia Song ◽  
...  
Keyword(s):  
Insulin Resistance ◽  
Glucose Uptake ◽  
Signaling Pathway ◽  
Insulin Signaling ◽  
Underlying Mechanism ◽  
Insulin Signaling Pathway ◽  
Akt Pathway ◽  
Public Health Issue ◽  
Pathway Activation ◽  
Candidate Target

AbstractThe incidence of obesity has increased rapidly, becoming a worldwide public health issue that involves insulin resistance. A growing number of recent studies have demonstrated that microRNAs play a significant role in controlling the insulin signaling network. For example, miR-506-3p expression has been demonstrated to correlate with insulin sensitivity; however, the underlying mechanism remains unknown. In this study, we found that miR-506-3p enhanced glucose uptake by 2-deoxy-D-glucose uptake assays and regulated the protein expression of key genes involved in the PI3K/AKT insulin signaling pathway including IRS1, PI3K, AKT, and GlUT4. We next predicted ribosomal protein S6 kinase B1 (S6K1) to be a candidate target of miR-506-3p by bioinformatics analysis and confirmed using dual-luciferase assays that miR-506-3p regulated S6K1 expression by binding to its 3′-UTR. Moreover, modulating S6K1 expression counteracted the effects of miR-506-3p on glucose uptake and PI3K/AKT pathway activation. In conclusion, miR-506-3p altered IR in adipocytes by regulating S6K1-mediated PI3K/AKT pathway activation. Taken together, these findings provide novel insights and potential targets for IR therapy.

High-power resistance exercise induces MAPK phosphorylation in weightlifting trained men

2012 ◽  
Vol 37 (1) ◽  
pp. 80-87 ◽  
Author(s):  
Andrew J. Galpin ◽  
Andrew C. Fry ◽  
Loren Z.F. Chiu ◽  
Donald B. Thomason ◽  
Brian K. Schilling
Keyword(s):  
Protein Kinase ◽  
Resistance Exercise ◽  
High Power ◽  
Vastus Lateralis ◽  
Muscle Performance ◽  
Mitogen Activated Protein Kinase ◽  
Mapk Phosphorylation ◽  
Mapk Pathways ◽  
Mitogen Activated Protein ◽  
Exercise Induced

Power is critical to muscle performance, specifically in athletic populations. Mitogen-activated protein kinase (MAPK) pathways (extracellular signal-regulated protein kinase (ERK 1/2), p38, and c-Jun NH2-terminal kinase (JNK)) are intracellular signal transduction mechanisms that partially regulate exercise-induced skeletal muscle alterations. These pathways are highly responsive to exercise, but their reaction to high power, multi-joint resistance exercise is yet to be examined. Nine weightlifting-trained men performed 15 sets of three repetitions of a dynamic clean pull exercise at 85% of their one repetition maximum. Vastus lateralis biopsies were obtained prior to (pre) and after the 8th (mid) and 15th set (post) of exercise. Three subjects returned to serve as non-exercising controls for a similar sequence of biopsies (CON). The ratio of phosphorylated MAPK to total MAPK increased significantly for p38 (3.0 fold, p < 0.05) and JNK (2.4 fold, p < 0.05) by the mid biopsy. ERK 1/2 phosphorylation followed a similar trend (2.3 fold) (p = 0.052). The ratio of phosphorylation to total MAPK did not differ from mid to post biopsy. None of the pathways were phosphorylated above resting in the CON condition (p > 0.05), and thus the biopsy procedure itself did not account for the entire increase in MAPK phosphorylation during EX. These data indicate MAPK pathways are activated early and remain elevated throughout the duration of high power resistance exercise. These findings help describe the mechanisms partially responsible for chronic adaptations in response to high intensity, high power resistance training in humans.

scholarly journals Homeobox B4 gene expression is upregulated by ghrelin through PI3-kinase signaling pathway in rat’s bone marrow stromal cells

2019 ◽  
Vol 53 (2) ◽  
pp. 65-70
Author(s):  
Shokoufeh Taherkhani ◽  
Fatemeh Moradi ◽  
Masoumeh Hosseini ◽  
Mohsen Alipour ◽  
Hadi Feizi
Keyword(s):  
Gene Expression ◽  
Bone Marrow ◽  
Protein Kinase ◽  
Stromal Cells ◽  
Bone Marrow Stromal Cells ◽  
Marrow Stromal Cells ◽  
Mitogen Activated Protein Kinase ◽  
Akt Pathway ◽  
The Future ◽  
Mitogen Activated Protein

AbstractObjective. Ghrelin, a 28 amino acid peptide, has diverse physiological roles. Phosphatidylino-sitol-bisphosphate 3-kinase (PI3K) and mitogen-activated protein kinase (MAPK) are involved in some of the recognized actions of ghrelin. It has been shown that ghrelin upregulates HOXB4 gene expression but the real mechanism of this effect is not clear.Methods. Rat bone marrow stromal cells (BMSCs) were cultured in DMEM. BMSCs were treated with ghrelin (100 μM) for 48 h. Real-time PCR for HOXB4 was performed from Control (untreated BMSCs), BG (BMSCs treated with 100 µM ghrelin), PD (BMSCs treated with 10 µM PD98059, a potent inhibitor of mitogen-activated protein kinase, and 100 µM ghrelin), LY (BM-SCs treated with 10 µM LY294002, a strong inhibitor of phosphoinositide 3-kinase, and 100 µM ghrelin) and SY (BMSCs treated with 10 µM LY294002 plus 10 µM PD98059, and 100 µM ghrelin) groups. Relative gene expression changes were determined using Relative expression software tool 9 (REST 9).Results. HOXB4 gene has been overexpressed in ghrelin-treated BMSCs (p<0.05). PI3K inhi-bition by LY294002 significantly downregulated the ghrelin-induced overexpression of HOXB4 (p<0.05).Conclusion. We can conclude that ghrelin, through PI3K/Akt pathway, may improve BMSC transplantation potency by reducing its apoptosis. Moreover, upregulating HOXB4 in BMSC and its possible differentiation to HSCs might in the future open the doors to new treatment for hematologic disorders. Therefore, activating the PI3K/Akt pathway, instead of using a non-specific inducer, could be the principal point to increase the efficiency of BMSC-based cell therapies in the future.

A possible role for AMP-activated protein kinase in exercise-induced glucose utilization: insights from humans and transgenic animals

2003 ◽  
Vol 31 (1) ◽  
pp. 186-190 ◽  
Author(s):  
J.N. Nielsen ◽  
S.B. Jørgensen ◽  
C. Frøsig ◽  
B. Viollet ◽  
F. Andreelli ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Protein Kinase ◽  
Glucose Uptake ◽  
Glucose Transport ◽  
Transgenic Animals ◽  
Conclusive Evidence ◽  
Exercise Induced ◽  
Tight Correlation ◽  
Amp Activated Protein Kinase

Exercise-induced glucose uptake in skeletal muscle is mediated by an insulin-independent mechanism, but the actual signals to glucose transport in response to muscle contraction have not been identified. The 5´-AMP-activated protein kinase (AMPK) has emerged as a putative mediator of contraction-induced glucose transport, although no conclusive evidence has been provided so far. Recent experiments in AMPK transgenic mice suggest that glucose transport induced by 5-amino-4-imidazolecarboxamide riboside (AICAR) or hypoxia is mediated by AMPK. In contrast, contraction-induced glucose transport in rodent skeletal muscle induced by electrical stimulation in vitro or in situ is not influenced or is only partially reduced by abolishing both or one of the catalytic AMPK subunits. This is compatible with exercise studies done in humans, where no tight correlation is found between AMPK activity and glucose uptake during exercise. Taken together, these results question an essential role of AMPK in exercise-induced glucose uptake and imply that one or more additional pathways are involved in mediating glucose transport in skeletal muscle during exercise.

Exercise-induced fall in insulin: mechanism of action at the liver and effects on muscle glucose metabolism

1994 ◽  
Vol 266 (5) ◽  
pp. E683-E689 ◽  
Author(s):  
B. A. Zinker ◽  
T. Mohr ◽  
P. Kelly ◽  
K. Namdaran ◽  
D. P. Bracy ◽  
...  
Keyword(s):  
Glucose Metabolism ◽  
Glucose Uptake ◽  
Femoral Vein ◽  
Vena Cava ◽  
External Iliac Artery ◽  
Glucose Production ◽  
Whole Body ◽  
Insulin Levels ◽  
Glucose Levels ◽  
Exercise Induced

To determine the importance of the fall in insulin on whole body glucose fluxes and muscle glucose metabolism during exercise, dogs ran on a motorized treadmill for 90 min at a moderate work rate with somatostatin (SRIF) infused to suppress insulin and glucagon and basal (B-INS; n = 6 dogs) or exercise-stimulated (S-INS; n = 8 dogs) insulin replacement. The fall in insulin during exercise potently stimulates glucose production at least in part by potentiating the actions of glucagon. To assess the hepatic effects of insulin in the absence of its potentiating effect on glucagon action, glucagon levels were not restored during SRIF infusion. At least 17 days before experimentation, dogs underwent surgery for chronic placement of sampling (carotid artery and femoral vein) and infusion (inferior vena cava and portal vein) catheters. Hindlimb blood flow was assessed by placement of a Doppler flow cuff on the external iliac artery. Whole body glucose production (Ra) and disappearance (Rd) were assessed with [3-3H]glucose, and hindlimb glucose uptake and metabolism were assessed with arterial-venous differences and [U-14C]glucose. Insulin levels were 69 +/- 6 and 61 +/- 7 pM at rest in B-INS and S-INS and 62 +/- 10 and 41 +/- 6 pM at 30 min of exercise. Glucose levels were clamped at euglycemic levels with an exogenous glucose infusion during rest and exercise in both groups. Exercise-induced increases in Ra, Rd, hindlimb glucose uptake, and hindlimb oxidative and nonoxidative glucose metabolism were not affected by maintenance of basil insulin levels during exercise.(ABSTRACT TRUNCATED AT 250 WORDS)

Importance of Elevated Circulating Hormones in Modulating Resistance Exercise-Induced Protein Kinase B Signaling in Fasted Men

2008 ◽  
Vol 40 (Supplement) ◽  
pp. S294
Author(s):  
Barry A. Spiering ◽  
William J. Kraemer ◽  
Jeffrey M. Anderson ◽  
Lawrence E. Armstrong ◽  
Bradley C. Nindl ◽  
...  
Keyword(s):  
Protein Kinase ◽  
Resistance Exercise ◽  
Protein Kinase B ◽  
Exercise Induced
Sign in / Sign up

Export Citation Format

Share Document