Coffee Improves Insulin-Stimulated Akt Phosphorylation in Liver and Skeletal Muscle in Diabetic KK-Ay Mice

Abstract Livestock animals are important dual-purpose models that benefit both agricultural and biomedical research. The neonatal pig is an appropriate model for the human infant to assess long-term effects of early life nutrition on growth and metabolic outcomes. Previously we have demonstrated that prematurity blunts the feeding-induced stimulation of translation initiation and protein synthesis in skeletal muscle of neonatal pigs. The objective of this study was to determine whether reduced sensitivity to insulin and/or amino acids drives this blunted response. Pigs were delivered by caesarean section at preterm (PT, 103 d gestation) or at term (T, 112 d gestation) and fed parenterally for 4 d. On day 4, pigs were subject to euinsulinemic-euaminoacidemic-euglycemic (FAST), hyperinsulinemic-euaminoacidemic-euglycemic (INS), or euinsulinemic-hyperaminoacidemic-euglycemic (AA) clamps for 120 min, yielding six treatments: PT-FAST (n = 7), PT-INS (n = 9), PT-AA (n = 9), T-FAST (n = 8), T-INS (n = 9), and T-AA (n = 9). A flooding dose of L-[4-3H]Phe was injected into pigs 30 min before euthanasia. Birth weight and relative body weight gain were lower in PT than T pigs (P < 0.001). Plasma insulin concentration was increased from ~3 to ~100 µU/mL in INS compared to FAST and AA pigs (P < 0.001); plasma BCAA concentration was increased from ~250 to ~1,000 µmol/L in AA compared to FAST and INS pigs (P < 0.001). Despite achieving similar insulin and amino acid levels, longissimus dorsi AKT phosphorylation, mechanistic target of rapamycin (mTOR)·Rheb abundance, mTOR activation, and protein synthesis were lower in PT-INS than T-INS pigs (Table 1). Although amino-acid induced dissociation of Sestrin2 from GATOR2 was not affected by prematurity, mTOR·RagA abundance, mTOR·RagC abundance, mTOR activation, and protein synthesis were lower in PT-AA than T-AA pigs. The impaired capacity of premature skeletal muscle to respond to insulin or amino acids and promote protein synthesis likely contributes to reduced lean mass accretion. Research was supported by NIH and USDA.

Download Full-text

NF-κB-Inducing Kinase (NIK) Mediates Skeletal Muscle Insulin Resistance: Blockade by Adiponectin

Endocrinology ◽

10.1210/en.2011-1343 ◽

2011 ◽

Vol 152 (10) ◽

pp. 3622-3627 ◽

Cited By ~ 26

Author(s):

Sanjeev Choudhary ◽

Sandeep Sinha ◽

Yanhua Zhao ◽

Srijita Banerjee ◽

Padma Sathyanarayana ◽

...

Keyword(s):

Insulin Resistance ◽

Skeletal Muscle ◽

Glucose Uptake ◽

Kinase Activity ◽

Pi3 Kinase ◽

Dominant Negative ◽

Muscle Insulin Resistance ◽

Akt Phosphorylation ◽

Skeletal Muscle Insulin Resistance ◽

Obese Subjects

Enhanced levels of nuclear factor (NF)-κB-inducing kinase (NIK), an upstream kinase in the NF-κB pathway, have been implicated in the pathogenesis of chronic inflammation in diabetes. We investigated whether increased levels of NIK could induce skeletal muscle insulin resistance. Six obese subjects with metabolic syndrome underwent skeletal muscle biopsies before and six months after gastric bypass surgery to quantitate NIK protein levels. L6 skeletal myotubes, transfected with NIK wild-type or NIK kinase-dead dominant negative plasmids, were treated with insulin alone or with adiponectin and insulin. Effects of NIK overexpression on insulin-stimulated glucose uptake were estimated using tritiated 2-deoxyglucose uptake. NF-κB activation (EMSA), phosphatidylinositol 3 (PI3) kinase activity, and phosphorylation of inhibitor κB kinase β and serine-threonine kinase (Akt) were measured. After weight loss, skeletal muscle NIK protein was significantly reduced in association with increased plasma adiponectin and enhanced AMP kinase phosphorylation and insulin sensitivity in obese subjects. Enhanced NIK expression in cultured L6 myotubes induced a dose-dependent decrease in insulin-stimulated glucose uptake. The decrease in insulin-stimulated glucose uptake was associated with a significant decrease in PI3 kinase activity and protein kinase B/Akt phosphorylation. Overexpression of NIK kinase-dead dominant negative did not affect insulin-stimulated glucose uptake. Adiponectin treatment inhibited NIK-induced NF-κB activation and restored insulin sensitivity by restoring PI3 kinase activation and subsequent Akt phosphorylation. These results indicate that NIK induces insulin resistance and further indicate that adiponectin exerts its insulin-sensitizing effect by suppressing NIK-induced skeletal muscle inflammation. These observations suggest that NIK could be an important therapeutic target for the treatment of insulin resistance associated with inflammation in obesity and type 2 diabetes.

Download Full-text

Myostatin inhibits proliferation and insulin-stimulated glucose uptake in mouse liver cells

Biochemistry and Cell Biology ◽

10.1139/bcb-2014-0004 ◽

2014 ◽

Vol 92 (3) ◽

pp. 226-234 ◽

Cited By ~ 16

Author(s):

Rani Watts ◽

Mostafa Ghozlan ◽

Curtis C. Hughey ◽

Virginia L. Johnsen ◽

Jane Shearer ◽

...

Keyword(s):

Skeletal Muscle ◽

Cell Proliferation ◽

Glucose Uptake ◽

Liver Cell ◽

Noncoding Rna ◽

Muscle Growth ◽

Liver Cells ◽

Negative Regulator ◽

Kinase Substrate ◽

Akt Phosphorylation

Although myostatin functions primarily as a negative regulator of skeletal muscle growth and development, accumulating biological and epidemiological evidence indicates an important contributing role in liver disease. In this study, we demonstrate that myostatin suppresses the proliferation of mouse Hepa-1c1c7 murine-derived liver cells (50%; p < 0.001) in part by reducing the expression of the cyclins and cyclin-dependent kinases that elicit G1-S phase transition of the cell cycle (p < 0.001). Furthermore, real-time PCR-based quantification of the long noncoding RNA metastasis associated lung adenocarcinoma transcript 1 (Malat1), recently identified as a myostatin-responsive transcript in skeletal muscle, revealed a significant downregulation (25% and 50%, respectively; p < 0.05) in the livers of myostatin-treated mice and liver cells. The importance of Malat1 in liver cell proliferation was confirmed via arrested liver cell proliferation (p < 0.05) in response to partial Malat1 siRNA-mediated knockdown. Myostatin also significantly blunted insulin-stimulated glucose uptake and Akt phosphorylation in liver cells while increasing the phosphorylation of myristoylated alanine-rich C-kinase substrate (MARCKS), a protein that is essential for cancer cell proliferation and insulin-stimulated glucose transport. Together, these findings reveal a plausible mechanism by which circulating myostatin contributes to the diminished regenerative capacity of the liver and diseases characterized by liver insulin resistance.

Download Full-text

Glucose-dependent insulinotropic polypeptide directly induces glucose transport in rat skeletal muscle

AJP Regulatory Integrative and Comparative Physiology ◽

10.1152/ajpregu.00003.2015 ◽

2015 ◽

Vol 309 (3) ◽

pp. R295-R303 ◽

Cited By ~ 5

Author(s):

Laelie A. Snook ◽

Emery M. Nelson ◽

David J. Dyck ◽

David C. Wright ◽

Graham P. Holloway

Keyword(s):

Skeletal Muscle ◽

Glucose Transport ◽

Soleus Muscle ◽

Serum Insulin ◽

Current Data ◽

Signaling Mechanism ◽

Akt Phosphorylation ◽

Glucose Challenge ◽

Muscle Glucose Transport

Several gastrointestinal proteins have been identified to have insulinotropic effects, including glucose-dependent insulinotropic polypeptide (GIP); however, the direct effects of incretins on skeletal muscle glucose transport remain largely unknown. Therefore, the purpose of the current study was to examine the role of GIP on skeletal muscle glucose transport and insulin signaling in rats. Relative to a glucose challenge, a mixed glucose+lipid oral challenge increased circulating GIP concentrations, skeletal muscle Akt phosphorylation, and improved glucose clearance by ∼35% ( P < 0.05). These responses occurred without alterations in serum insulin concentrations. In an incubated soleus muscle preparation, GIP directly stimulated glucose transport and increased GLUT4 accumulation on the plasma membrane in the absence of insulin. Moreover, the ability of GIP to stimulate glucose transport was mitigated by the addition of the PI 3-kinase (PI3K) inhibitor wortmannin, suggesting that signaling through PI3K is required for these responses. We also provide evidence that the combined stimulatory effects of GIP and insulin on soleus muscle glucose transport are additive. However, the specific GIP receptor antagonist (Pro3)GIP did not attenuate GIP-stimulated glucose transport, suggesting that GIP is not signaling through its classical receptor. Together, the current data provide evidence that GIP regulates skeletal muscle glucose transport; however, the exact signaling mechanism(s) remain unknown.

Download Full-text

Skeletal Muscle-Selective Knockout of LKB1 Increases Insulin Sensitivity, Improves Glucose Homeostasis, and Decreases TRB3

Molecular and Cellular Biology ◽

10.1128/mcb.00979-06 ◽

2006 ◽

Vol 26 (22) ◽

pp. 8217-8227 ◽

Cited By ~ 155

Author(s):

Ho-Jin Koh ◽

David E. Arnolds ◽

Nobuharu Fujii ◽

Thien T. Tran ◽

Marc J. Rogers ◽

...

Keyword(s):

Skeletal Muscle ◽

Insulin Sensitivity ◽

Glucose Homeostasis ◽

Glucose Utilization ◽

Cell Metabolism ◽

Negative Regulator ◽

Akt Inhibitor ◽

Akt Phosphorylation ◽

Energy Sensing

ABSTRACT LKB1 is a tumor suppressor that may also be fundamental to cell metabolism, since LKB1 phosphorylates and activates the energy sensing enzyme AMPK. We generated muscle-specific LKB1 knockout (MLKB1KO) mice, and surprisingly, found that a lack of LKB1 in skeletal muscle enhanced insulin sensitivity, as evidenced by decreased fasting glucose and insulin concentrations, improved glucose tolerance, increased muscle glucose uptake in vivo, and increased glucose utilization during a hyperinsulinemic-euglycemic clamp. MLKB1KO mice had increased insulin-stimulated Akt phosphorylation and a >80% decrease in muscle expression of TRB3, a recently identified Akt inhibitor. Akt/TRB3 binding was present in skeletal muscle, and overexpression of TRB3 in C2C12 myoblasts significantly reduced Akt phosphorylation. These results demonstrate that skeletal muscle LKB1 is a negative regulator of insulin sensitivity and glucose homeostasis. LKB1-mediated TRB3 expression provides a novel link between LKB1 and Akt, critical kinases involved in both tumor genesis and cell metabolism.

Download Full-text

Impaired insulin-stimulated glucose transport in ATM-deficient mouse skeletal muscle

Applied Physiology Nutrition and Metabolism ◽

10.1139/apnm-2012-0175 ◽

2013 ◽

Vol 38 (6) ◽

pp. 589-596 ◽

Cited By ~ 5

Author(s):

James Kain Ching ◽

Larry D. Spears ◽

Jennifer L. Armon ◽

Allyson L. Renth ◽

Stanley Andrisse ◽

...

Keyword(s):

Skeletal Muscle ◽

Glucose Transport ◽

Cell Types ◽

Glucose Disposal ◽

Wild Type ◽

Phosphatidylinositol 3 Kinase ◽

Ataxia Telangiectasia Mutated ◽

Akt Phosphorylation ◽

Atm Protein

There are reports that ataxia telangiectasia mutated (ATM) plays a role in insulin-stimulated Akt phosphorylation, although this is not the case in some cell types. Because Akt plays a key role in insulin signaling, which leads to glucose transport in skeletal muscle, the predominant tissue in insulin-stimulated glucose disposal, we examined whether insulin-stimulated Akt phosphorylation and (or) glucose transport would be decreased in skeletal muscle of mice lacking functional ATM, compared with muscle from wild-type mice. We found that in vitro insulin-stimulated Akt phosphorylation was normal in soleus muscle from mice with 1 nonfunctional allele of ATM (ATM+/−) and from mice with 2 nonfunctional alleles (ATM−/−). However, insulin did not stimulate glucose transport or the phosphorylation of AS160 in ATM−/− soleus. ATM protein level was markedly higher in wild-type extensor digitorum longus (EDL) than in wild-type soleus. In EDL from ATM−/− mice, insulin did not stimulate glucose transport. However, in contrast to findings for soleus, insulin-stimulated Akt phosphorylation was blunted in ATM−/− EDL, concomitant with a tendency for insulin-stimulated phosphatidylinositol 3-kinase activity to be decreased. Together, the findings suggest that ATM plays a role in insulin-stimulated glucose transport at the level of AS160 in muscle comprised of slow and fast oxidative-glycolytic fibers (soleus) and at the level of Akt in muscle containing fast glycolytic fibers (EDL).

Download Full-text

Calorie Restriction Enhances Insulin-Stimulated Glucose Uptake and Akt Phosphorylation in Both Fast-Twitch and Slow-Twitch Skeletal Muscle of 24-Month-Old Rats

The Journals of Gerontology Series A ◽

10.1093/gerona/gls085 ◽

2012 ◽

Vol 67 (12) ◽

pp. 1279-1285 ◽

Cited By ~ 23

Author(s):

D. A. Sequea ◽

N. Sharma ◽

E. B. Arias ◽

G. D. Cartee

Keyword(s):

Skeletal Muscle ◽

Glucose Uptake ◽

Calorie Restriction ◽

Akt Phosphorylation ◽

Old Rats ◽

Slow Twitch ◽

Fast Twitch

Download Full-text

A novel Alaska pollack-derived peptide, which increases glucose uptake in skeletal muscle cells, lowers the blood glucose level in diabetic mice

Food & Function ◽

10.1039/c5fo00401b ◽

2015 ◽

Vol 6 (8) ◽

pp. 2749-2757 ◽

Cited By ~ 5

Author(s):

Tatsuhiro Ayabe ◽

Takafumi Mizushige ◽

Wakana Ota ◽

Fuminori Kawabata ◽

Kohsuke Hayamizu ◽

...

Keyword(s):

Skeletal Muscle ◽

Blood Glucose ◽

Blood Glucose Level ◽

Glucose Uptake ◽

Type Ii ◽

Diabetic Mice ◽

Glucose Lowering ◽

Tryptic Digest ◽

Glucose Lowering Effect ◽

Ay Mice

We found that the tryptic digest of Alaska pollack protein (APP) and novel APP-derived peptide exhibited a glucose-lowering effect in KK-Ay mice, a type II diabetic mice.

Download Full-text

Ceramide inhibits insulin-stimulated Akt phosphorylation through activation of Rheb/mTORC1/S6K signaling in skeletal muscle

Cellular Signalling ◽

10.1016/j.cellsig.2014.03.004 ◽

2014 ◽

Vol 26 (7) ◽

pp. 1400-1408 ◽

Cited By ~ 27

Author(s):

Chang-Ting Hsieh ◽

Jen-Hua Chuang ◽

Wen-Chin Yang ◽

Yi Yin ◽

Yenshou Lin

Keyword(s):

Skeletal Muscle ◽

Akt Phosphorylation

Download Full-text