scholarly journals Exercise and type 2 diabetes: molecular mechanisms regulating glucose uptake in skeletal muscle

2014 ◽  
Vol 38 (4) ◽  
pp. 308-314 ◽  
Author(s):  
Kristin I. Stanford ◽  
Laurie J. Goodyear

Exercise is a well-established tool to prevent and combat type 2 diabetes. Exercise improves whole body metabolic health in people with type 2 diabetes, and adaptations to skeletal muscle are essential for this improvement. An acute bout of exercise increases skeletal muscle glucose uptake, while chronic exercise training improves mitochondrial function, increases mitochondrial biogenesis, and increases the expression of glucose transporter proteins and numerous metabolic genes. This review focuses on the molecular mechanisms that mediate the effects of exercise to increase glucose uptake in skeletal muscle.

2009 ◽  
Vol 203 (1) ◽  
pp. 65-74 ◽  
Author(s):  
Yun Wang ◽  
Patsy M Nishina ◽  
Jürgen K Naggert

The TALLYHO/Jng (TH) mouse strain is a polygenic model for type 2 diabetes (T2D) characterized by moderate obesity, impaired glucose tolerance and uptake, insulin resistance, and hyperinsulinemia. The goal of this study was to elucidate the molecular mechanisms responsible for the reduced glucose uptake and insulin resistance in the adipose tissue of this model. The translocation and localization of glucose transporter 4 (GLUT4) to the adipocyte plasma membrane were impaired in TH mice compared to control C57BL6/J (B6) mice. These defects were associated with decreased GLUT4 protein, reduced phosphatidylinositol 3-kinase activity, and alterations in the phosphorylation status of insulin receptor substrate 1 (IRS1). Activation of c-Jun N-terminal kinase 1/2, which can phosphorylate IRS1 on Ser307, was significantly higher in TH mice compared with B6 controls. IRS1 protein but not mRNA levels was found to be lower in TH mice than controls. Immunoprecipitation with anti-ubiquitin and western blot analysis of IRS1 protein revealed increased total IRS1 ubiquitination in adipose tissue of TH mice. Suppressor of cytokine signaling 1, known to promote IRS1 ubiquitination and subsequent degradation, was found at significantly higher levels in TH mice compared with B6. Immunohistochemistry showed that IRS1 colocalized with the 20S proteasome in proteasomal structures in TH adipocytes, supporting the notion that IRS1 is actively degraded. Our findings suggest that increased IRS1 degradation and subsequent impaired GLUT4 mobilization play a role in the reduced glucose uptake in insulin resistant TH mice. Since low-IRS1 levels are often observed in human T2D, the TH mouse is an attractive model to investigate mechanisms of insulin resistance and explore new treatments.


2020 ◽  
pp. 088532822094734 ◽  
Author(s):  
Xinlu Yuan ◽  
Ling Ding ◽  
Jianjun Diao ◽  
Song Wen ◽  
Chenglin Xu ◽  
...  

Metformin, the first-line drug to treat type 2 diabetes, inhibits mitochondrial glycerolphosphate dehydrogenase in the liver to suppress gluconeogenesis. The major adverse effects caused by metformin were lactic acidosis and gastrointestinal discomfort. Therefore, there is need to develop a strategy with excellent permeability and appropriate retention effects.In this study, we synthesized a simple and biocompatible PolyMetformin (denoted as PolyMet) through conjugation of PEI1.8K with dicyandiamide, and then formed PolyMet-hyaluronic acid (HA) nanocomplexs by electrostatic self-assembly of the polycationic PolyMet and polyanionic hyaluronic acid (HA). Similar to metformin, the PolyMet-HA nanocomplexs could reduce the catalytic activity of the recombinant SHIP2 phosphatase domain in vitro. In SHIP2-overexpressing myotubes, PolyMet-HA nanocomplexes ameliorated glucose uptake by downregulating glucose transporter 4 endocytosis. PolyMet-HA nanocomplexes also could restore Akt signaling and protect the podocyte from apoptosis induced by SHIP2 overexpression. In essence, the PolyMet-HA nanocomplexes act similarly to metformin and increase glucose uptake, and maybe have a potential role in the treatment of type 2 diabetes.


2018 ◽  
Vol 50 (08) ◽  
pp. 627-639 ◽  
Author(s):  
Gretha Boersma ◽  
Emil Johansson ◽  
Maria Pereira ◽  
Kerstin Heurling ◽  
Stanko Skrtic ◽  
...  

AbstractWe assessed glucose uptake in different tissues in type 2 diabetes (T2D), prediabetes, and control subjects to elucidate its impact in the development of whole-body insulin resistance and T2D. Thirteen T2D, 12 prediabetes, and 10 control subjects, matched for age and BMI, underwent OGTT and abdominal subcutaneous adipose tissue (SAT) biopsies. Integrated whole-body 18F-FDG PET and MRI were performed during a hyperinsulinemic euglycemic clamp to asses glucose uptake rate (MRglu) in several tissues. MRglu in skeletal muscle, SAT, visceral adipose tissue (VAT), and liver was significantly reduced in T2D subjects and correlated positively with M-values (r=0.884, r=0.574, r=0.707 and r=0.403, respectively). Brain MRglu was significantly higher in T2D and prediabetes subjects and had a significant inverse correlation with M-values (r=–0.616). Myocardial MRglu did not differ between groups and did not correlate with the M-values. A multivariate model including skeletal muscle, brain and VAT MRglu best predicted the M-values (adjusted r2=0.85). In addition, SAT MRglu correlated with SAT glucose uptake ex vivo (r=0.491). In different stages of the development of T2D, glucose uptake during hyperinsulinemia is elevated in the brain in parallel with an impairment in peripheral organs. Impaired glucose uptake in skeletal muscle and VAT together with elevated glucose uptake in brain were independently associated with whole-body insulin resistance, and these tissue-specific alterations may contribute to T2D development.


2020 ◽  
Vol 4 (Supplement_1) ◽  
Author(s):  
Alba Moreno-Asso ◽  
Luke C McIlvenna ◽  
Rhiannon K Patten ◽  
Andrew J McAinch ◽  
Raymond J Rodgers ◽  
...  

Abstract Polycystic ovary syndrome (PCOS) is the most common female endocrine disorder affecting metabolic, reproductive and mental health of 8-13% of reproductive-age women. Insulin resistance (IR) appears to underpin the pathophysiology of PCOS and is present in approximately 85% of women with PCOS. This underlying IR has been identified as unique from, but synergistic with, obesity-induced IR (1). Skeletal muscle accounts for up to 85% of whole body insulin-stimulated glucose uptake, however, in PCOS this is reduced about 27% when assessed by hyperinsulinemic euglycemic clamp (2). Interestingly, this reduced insulin-stimulated glucose uptake observed in skeletal muscle tissue is not retained in cultured myotubes (3), suggesting that environmental factors may play a role in this PCOS-specific IR. Yet, the molecular mechanisms regulating IR remain unclear (4). Previous work suggested that Transforming Growth Factor Beta (TGFβ) superfamily ligands may be involved in the metabolic morbidity associated with PCOS (5). In this study, we investigated the effects of TGFβ1 (1, 5ng/ml), and the Anti-Müllerian hormone (AMH; 5, 10, 30ng/ml), a novel TGFβ superfamily ligand elevated in women with PCOS, as causal factors of IR in cultured myotubes from women with PCOS (n=10) and healthy controls (n=10). AMH negatively affected glucose uptake and insulin signalling increasing p-IRS1 (ser312) in a dose-dependent manner in myotubes from both women with and without PCOS. AMH did not appear to activate the canonical TGFβ/BMP signalling pathway. Conversely, TGFβ1 had an opposite effect in both PCOS and control myotubes cultures, decreasing phosphorylation of IRS1 (ser312) and enhancing glucose uptake via Smad2/3 signalling. In conclusion, these results suggest that AMH may play a role in skeletal muscle IR observed in PCOS, however, further research is required to elucidate its mechanisms of action and broader impact in this syndrome. References: (1) Stepto et al. Hum Reprod 2013 Mar;28(3):777-784. (2) Cassar et al. Hum Reprod 2016 Nov;31(11):2619-2631. (3) Corbould et al., Am J Physiol-Endoc 2005 May;88(5):E1047-54. (4) Stepto et al. J Clin Endocrinol Metab, 2019 Nov 1;104(11):5372-5381. (5) Raja-Khan et al. Reprod Sci 2014 Jan;21(1):20-31.


2020 ◽  
Vol 8 (1) ◽  
pp. e001027 ◽  
Author(s):  
Tomonori Kimura ◽  
Takuro Okamura ◽  
Keiko Iwai ◽  
Yoshitaka Hashimoto ◽  
Takafumi Senmaru ◽  
...  

ObjectiveReduction of muscle mass and strength is an important treatment target for patients with type 2 diabetes. Recent studies have reported that high-intensity resistance training improves physical function; however, all patients found it difficult to perform high-intensity resistance training. Radio calisthenics, considered as therapeutic exercises to promote health in Japan, are simple exercises that can be performed regardless of age and help move the muscles and joints of the whole body effectively according to the rhythm of radio. We investigated the efficacy of radio calisthenics for muscle mass in patients with type 2 diabetes in this retrospective cohort study.Research design and methodsA total of 42 hospitalized patients with type 2 diabetes were recruited. The skeletal muscle mass index (SMI, kg/m2) was calculated as appendicular muscle mass (kg) divided by height squared (m2). We defined the change of SMI as the difference of SMI between the beginning and end of hospitalization.ResultsAmong 42 patients, 15 (11 men and 4 women) performed radio calisthenics. Body weights of both radio calisthenics exercisers and non-exercisers decreased during hospitalization. The change of SMI was significantly lesser in radio calisthenics exercisers than in non-exercisers (7.1±1.4 to 7.1±1.3, –0.01±0.09 vs 6.8±1.1 to 6.5±1.2, –0.27±0.06 kg/m2, p=0.016). The proportion of decreased SMI was 85.2% (23/27 patients) in non-radio calisthenics exercisers, whereas that in radio calisthenics exercisers was 46.7% (7/15 patients).ConclusionsRadio calisthenics prevent the reduction of skeletal muscle mass. Thus, radio calisthenics can be considered effective for patients with type 2 diabetes.


2012 ◽  
Vol 2012 ◽  
pp. 1-9 ◽  
Author(s):  
S. E. Hurst ◽  
S. C. Minkin ◽  
J. Biggerstaff ◽  
M. S. Dhar

Atp10cis a strong candidate gene for diet-induced obesity and type 2 diabetes. To identify molecular and cellular targets of ATP10C,Atp10cexpression was alteredin vitroin C2C12 skeletal muscle myotubes by transient transfection with anAtp10c-specific siRNA. Glucose uptake assays revealed that insulin stimulation caused a significant 2.54-fold decrease in 2-deoxyglucose uptake in transfected cells coupled with a significant upregulation of native mitogen-activated protein kinases (MAPKs), p38, and p44/42. Additionally, glucose transporter-1 (GLUT1) was significantly upregulated; no changes in glucose transporter-4 (GLUT4) expression were observed. The involvement of MAPKs was confirmed using the specific inhibitor SB203580, which downregulated the expression of native and phosphorylated MAPK proteins in transfected cells without any changes in insulin-stimulated glucose uptake. Results indicate thatAtp10cregulates glucose metabolism, at least in part via the MAPK pathway, and, thus, plays a significant role in the development of insulin resistance and type 2 diabetes.


2014 ◽  
Vol 306 (9) ◽  
pp. E1065-E1076 ◽  
Author(s):  
Hidemitsu Sakagami ◽  
Yuichi Makino ◽  
Katsutoshi Mizumoto ◽  
Tsubasa Isoe ◽  
Yasutaka Takeda ◽  
...  

Defects in glucose uptake by the skeletal muscle cause diseases linked to metabolic disturbance such as type 2 diabetes. The molecular mechanism determining glucose disposal in the skeletal muscle in response to cellular stimuli including insulin, however, remains largely unknown. The hypoxia-inducible factor-1α (HIF-1α) is a transcription factor operating in the cellular adaptive response to hypoxic conditions. Recent studies have uncovered pleiotropic actions of HIF-1α in the homeostatic response to various cellular stimuli, including insulin under normoxic conditions. Thus we hypothesized HIF-1α is involved in the regulation of glucose metabolism stimulated by insulin in the skeletal muscle. To this end, we generated C2C12myocytes in which HIF-1α is knocked down by short-hairpin RNA and examined the intracellular signaling cascade and glucose uptake subsequent to insulin stimulation. Knockdown of HIF-1α expression in the skeletal muscle cells resulted in abrogation of insulin-stimulated glucose uptake associated with impaired mobilization of glucose transporter 4 (GLUT4) to the plasma membrane. Such defect seemed to be caused by reduced phosphorylation of the protein kinase B substrate of 160 kDa (AS160). AS160 phosphorylation and GLUT4 translocation by AMP-activated protein kinase activation were abrogated as well. In addition, expression of the constitutively active mutant of HIF-1α (CA-HIF-1α) or upregulation of endogenous HIF-1α in C2C12cells shows AS160 phosphorylation comparable to the insulin-stimulated level even in the absence of insulin. Accordingly GLUT4 translocation was increased in the cells expressing CA-HIF1α. Taken together, HIF-1α is a determinant for GLUT4-mediated glucose uptake in the skeletal muscle cells thus as a possible target to alleviate impaired glucose metabolism in, e.g., type 2 diabetes.


2005 ◽  
Vol 99 (3) ◽  
pp. 1220-1225 ◽  
Author(s):  
SoJung Lee ◽  
Jennifer L. Kuk ◽  
Lance E. Davidson ◽  
Robert Hudson ◽  
Katherine Kilpatrick ◽  
...  

It is unclear whether chronic exercise without caloric restriction or weight loss is a useful strategy for obesity reduction in obese men with and without Type 2 diabetes (T2D). We examined the effects of exercise without weight loss on total and regional adiposity and skeletal muscle mass and composition in lean men and in obese men with and without T2D. Twenty-four men participated in 13 wk of supervised aerobic exercise, five times per week for 60 min at a moderate intensity (∼60% peak oxygen uptake). Total and regional body composition was measured by magnetic resonance imaging. Skeletal muscle composition was determined using computed tomography. Cardiorespiratory fitness was assessed using a graded maximal treadmill test. Body weight did not change within any group in response to exercise ( P > 0.1). Significant reductions in total, abdominal subcutaneous, and visceral fat were observed within each group ( P < 0.01). The reduction in total and abdominal subcutaneous fat was not different ( P > 0.1) between groups; however, the reduction in visceral fat was greater ( P < 0.01) in the obese and T2D groups by comparison to the lean group. A significant ( P < 0.01) increase in total skeletal muscle, high-density muscle area, and mean muscle attenuation was observed independent of group, and these changes were not different between groups ( P > 0.1). Accordingly, whole body fat-to-muscle ratio was increased ( P < 0.01) independent of groups. In conclusion, regular exercise without weight loss is associated with a substantial reduction in total and visceral fat and in skeletal muscle lipid in both obesity and T2D.


Metabolism ◽  
2015 ◽  
Vol 64 (12) ◽  
pp. 1619-1628 ◽  
Author(s):  
Júlia Matzenbacher dos Santos ◽  
Marcos Lazaro Moreli ◽  
Shikha Tewari ◽  
Sandra Aparecida Benite-Ribeiro

2013 ◽  
Vol 455 (2) ◽  
pp. e1-e3
Author(s):  
James S. V. Lally ◽  
Gregory R. Steinberg

Skeletal muscle is critical for whole-body glucose homoeostasis. Insulin and muscle contractions induced by exercise can increase glucose uptake through distinct intracellular signalling pathways involving PKB (protein kinase B)/Akt and AMPK (AMP-activated protein kinase) respectively. Whereas the proximal events governing these processes are becoming well understood, less is known about the regulation of the complex events necessary for the control of glucose uptake at the plasma membrane. In recent years, a number of common targets of AMPK and PKB/Akt have emerged as important components controlling glucose uptake, but the necessary phosphorylation events required for the control of glucose uptake have remained more elusive. In the current issue of the Biochemical Journal, Liu et al. identify that PIKfyve, a phosphoinositide phosphate kinase, is required for contraction-stimulated glucose uptake. They demonstrate that AMPK directly phosphorylates PIKfyve at Ser307, the same site as PKB/Akt, and that phosphorylation is increased in response to muscle contractions. These data provide compelling evidence for a new AMPK substrate that converges with PKB/Akt signalling and may be critical for the control of glucose uptake in skeletal muscle.


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