Phosphatidylinositol 4-kinase IIIβ mediates contraction-induced GLUT4 translocation and shows its anti-diabetic action in cardiomyocytes

Abstract In the diabetic heart, long-chain fatty acid (LCFA) uptake is increased at the expense of glucose uptake. This metabolic shift ultimately leads to insulin resistance and a reduced cardiac function. Therefore, signaling kinases that mediate glucose uptake without simultaneously stimulating LCFA uptake could be considered attractive anti-diabetic targets. Phosphatidylinositol-4-kinase-IIIβ (PI4KIIIβ) is a lipid kinase downstream of protein kinase D1 (PKD1) that mediates Golgi-to-plasma membrane vesicular trafficking in HeLa-cells. In this study, we evaluated whether PI4KIIIβ is involved in myocellular GLUT4 translocation induced by contraction or oligomycin (an F1F0-ATP synthase inhibitor that activates contraction-like signaling). Pharmacological targeting, with compound MI14, or genetic silencing of PI4KIIIβ inhibited contraction/oligomycin-stimulated GLUT4 translocation and glucose uptake in cardiomyocytes but did not affect CD36 translocation nor LCFA uptake. Addition of the PI4KIIIβ enzymatic reaction product phosphatidylinositol-4-phosphate restored oligomycin-stimulated glucose uptake in the presence of MI14. PI4KIIIβ activation by PKD1 involves Ser294 phosphorylation and altered its localization with unchanged enzymatic activity. Adenoviral PI4KIIIβ overexpression stimulated glucose uptake, but did not activate hypertrophic signaling, indicating that unlike PKD1, PI4KIIIβ is selectively involved in GLUT4 translocation. Finally, PI4KIIIβ overexpression prevented insulin resistance and contractile dysfunction in lipid-overexposed cardiomyocytes. Together, our studies identify PI4KIIIβ as positive and selective regulator of GLUT4 translocation in response to contraction-like signaling, suggesting PI4KIIIβ as a promising target to rescue defective glucose uptake in diabetics.

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Protein kinase‐D1 overexpression in mice prevents lipid‐induced insulin resistance and cardiomyopathy by upregulation of glucose uptake

The FASEB Journal ◽

10.1096/fasebj.25.1_supplement.914.3 ◽

2011 ◽

Vol 25 (S1) ◽

Author(s):

Ellen Dirkx ◽

Robert W. Schwenk ◽

Laura KM Steinbusch ◽

Nicole Hoebers ◽

Ben J Janssen ◽

...

Keyword(s):

Insulin Resistance ◽

Protein Kinase ◽

Glucose Uptake ◽

Protein Kinase D1

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Abstract 308: Rgs2 Is An Endogenous Inhibitor Of Insulin Signaling

Circulation ◽

10.1161/circ.118.suppl_18.s_282 ◽

2008 ◽

Vol 118 (suppl_18) ◽

Author(s):

Prem Sharma ◽

Jennie Bever ◽

Scott Heximer ◽

Carmen Dessauer ◽

Jerrold M Olefsky

Keyword(s):

Insulin Resistance ◽

Insulin Sensitivity ◽

Glucose Uptake ◽

Insulin Signaling ◽

Regulatory System ◽

Heart Association ◽

Glut4 Translocation ◽

Wild Type ◽

Akt Phosphorylation ◽

Insulin Resistant

Background: Insulin resistance is the hallmark of type 2 diabetes and is a known risk factor for the development of cardiovascular diseases. We have determined that overexpression of a GTPase-activating protein, RGS2 decreases insulin sensitivity. This study describes RGS2 regulation of insulin signaling pathways in order to assess whether this information can be used to reverse insulin insensitivity in diabetes. Hypothesis, Methods and Results: RGS2 protein levels were elevated 3 to 5-fold in white adipose tissues from ob/ob and high fat diet induced Insulin Resistant mice. Further, RGS2 protein is elevated in insulin resistant 3T3-L1 adipocytes treated chronically with either insulin, ET-1, or TNF-aplha. Further, SiRNA knockdown of endogenous RGS2 protein increases basal, insulin independent and insulin-dependent GLUT4 translocation. We hypothesized that the RGS2 regulatory system is defective/overactive in insulin resistance, and that a modulation of this regulatory system by RGS2 inhibition would improve insulin sensitivity. Thus, we determined the mechanisms whereby RGS2 modulates insulin sensitivity in 3T3-L1 adipocytes; focusing on insulin-regulated G-protein/PI3-K pathways leading to GLUT4 translocation and glucose uptake; utilizing adenoviruses over-expressing wild-type and mutants RGS2, as well as by siRNA-mediated knock down of endogenous RGS2. We overexpressed the Wild-Type (WT), GTPase defective (GD), and plasma membrane translocation defective (TD) RGS2 proteins in 3T3-L1 adipocytes. Overexpression of WT RGS2 leads to ~ 50% inhibition of insulin induced 2-DOG uptake, without affecting IR Tyr phosphorylation. RGS2 constitutively associates with Galpha/q11, and prevent its Tyr phosphorylation and activation by insulin. Interestingly, insulin-stimulated PKClambda phosphorylation was completely blocked by RGS2, whereas, AKT phosphorylation was minimally inhibited. Neither the insulin receptor tyrosine phosphorylation nor insulin-stimulated MAPK phosphorylation was affected by RGS2. Conclusion: This study identifies a novel role of RGS2 in cellular insulin resistance by negatively regulating signaling through the Galpha/q11 pathway to glucose uptake. This research has received full or partial funding support from the American Heart Association, AHA Western States Affiliate (California, Nevada & Utah).

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MicroRNAs-Mediated Regulation of Skeletal Muscle GLUT4 Expression and Translocation in Insulin Resistance

Journal of Diabetes Research ◽

10.1155/2017/7267910 ◽

2017 ◽

Vol 2017 ◽

pp. 1-11 ◽

Cited By ~ 35

Author(s):

João Victor Esteves ◽

Francisco Javier Enguita ◽

Ubiratan Fabres Machado

Keyword(s):

Insulin Resistance ◽

Skeletal Muscle ◽

Glycemic Control ◽

Glucose Uptake ◽

Glucose Transporter ◽

Regulation Of Gene Expression ◽

Glut4 Translocation ◽

Therapeutic Approaches ◽

Glut4 Expression ◽

Solute Carrier

The solute carrier family 2 facilitated glucose transporter member 4 (GLUT4) plays a key role in the insulin-induced glucose uptake by muscle and adipose tissues. In prediabetes and diabetes, GLUT4 expression/translocation has been detected as reduced, participating in mechanisms that impair glycemic control. Recently, a class of short endogenous noncoding RNAs named microRNAs (miRNAs) has been increasingly described as involved in the posttranscriptional epigenetic regulation of gene expression. The present review focuses on miRNAs potentially involved in the expression of GLUT4 expression, and proteins related to GLUT4 and translocation in skeletal muscle, seeking to correlate them with insulin resistance and diabetes. So far, miR-21a-5p, miR-29a-3p, miR-29c-3p, miR-93-5p, miR-106b-5p, miR-133a-3p, miR-133b-3p, miR-222-3p, and miR-223-3p have been reported to directly and/or indirectly regulate the GLUT4 expression; and their expression is altered under diabetes-related conditions. Besides, some miRNAs that have been linked to the expression of proteins involved in GLUT4 translocation machinery in muscle could also impact glucose uptake. That makes these miRNAs promising targets for preventive and/or therapeutic approaches, which could improve glycemic control, thus deserving future new investigations.

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Muscle-specific Pikfyve gene disruption causes glucose intolerance, insulin resistance, adiposity, and hyperinsulinemia but not muscle fiber-type switching

AJP Endocrinology and Metabolism ◽

10.1152/ajpendo.00030.2013 ◽

2013 ◽

Vol 305 (1) ◽

pp. E119-E131 ◽

Cited By ~ 22

Author(s):

Ognian C. Ikonomov ◽

Diego Sbrissa ◽

Khortnal Delvecchio ◽

Han-Zhong Feng ◽

Gregory D. Cartee ◽

...

Keyword(s):

Insulin Resistance ◽

Skeletal Muscle ◽

Fatty Acid ◽

Glucose Uptake ◽

Glucose Intolerance ◽

Fat Mass ◽

Gene Disruption ◽

Glut4 Translocation ◽

Fat Cell

The evolutionarily conserved kinase PIKfyve that synthesizes PtdIns5P and PtdIns(3,5)P2 has been implicated in insulin-regulated GLUT4 translocation/glucose entry in 3T3-L1 adipocytes. To decipher PIKfyve's role in muscle and systemic glucose metabolism, here we have developed a novel mouse model with Pikfyve gene disruption in striated muscle (MPIfKO). These mice exhibited systemic glucose intolerance and insulin resistance at an early age but had unaltered muscle mass or proportion of slow/fast-twitch muscle fibers. Insulin stimulation of in vivo or ex vivo glucose uptake and GLUT4 surface translocation was severely blunted in skeletal muscle. These changes were associated with premature attenuation of Akt phosphorylation in response to in vivo insulin, as tested in young mice. Starting at 10–11 wk of age, MPIfKO mice progressively accumulated greater body weight and fat mass. Despite increased adiposity, serum free fatty acid and triglyceride levels were normal until adulthood. Together with the undetectable lipid accumulation in liver, these data suggest that lipotoxicity and muscle fiber switching do not contribute to muscle insulin resistance in MPIfKO mice. Furthermore, the 80% increase in total fat mass resulted from increased fat cell size rather than altered fat cell number. The observed profound hyperinsulinemia combined with the documented increases in constitutive Akt activation, in vivo glucose uptake, and gene expression of key enzymes for fatty acid biosynthesis in MPIfKO fat tissue suggest that the latter is being sensitized for de novo lipid anabolism. Our data provide the first in vivo evidence that PIKfyve is essential for systemic glucose homeostasis and insulin-regulated glucose uptake/GLUT4 translocation in skeletal muscle.

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Differential regulation of cardiac glucose and fatty acid uptake by endosomal pH and actin filaments

AJP Cell Physiology ◽

10.1152/ajpcell.00334.2009 ◽

2010 ◽

Vol 298 (6) ◽

pp. C1549-C1559 ◽

Cited By ~ 29

Author(s):

Laura K. M. Steinbusch ◽

Wino Wijnen ◽

Robert W. Schwenk ◽

Will A. Coumans ◽

Nicole T. H. Hoebers ◽

...

Keyword(s):

Fatty Acid ◽

Glucose Uptake ◽

Actin Filaments ◽

Acid Uptake ◽

Substrate Uptake ◽

Coat Proteins ◽

Glut4 Translocation ◽

Endosomal Ph ◽

Lcfa Uptake

Insulin and contraction stimulate both cardiac glucose and long-chain fatty acid (LCFA) uptake via translocation of the substrate transporters GLUT4 and CD36, respectively, from intracellular compartments to the sarcolemma. Little is known about the role of vesicular trafficking elements in insulin- and contraction-stimulated glucose and LCFA uptake in the heart, especially whether certain trafficking elements are specifically involved in GLUT4 versus CD36 translocation. Therefore, we studied the role of coat proteins, actin- and microtubule-filaments and endosomal pH on glucose and LCFA uptake into primary cardiomyocytes under basal conditions and during stimulation with insulin or oligomycin (contraction-like AMP-activated protein kinase activator). Inhibition of coat protein targeting to Golgi/endosomes decreased insulin/oligomycin-stimulated glucose (−42%/−51%) and LCFA (−39%/−68%) uptake. Actin disruption decreased insulin/oligomycin-stimulated glucose uptake (−41%/−75%), while not affecting LCFA uptake. Microtubule disruption did not affect substrate uptake under any condition. Endosomal alkalinization increased basal sarcolemmal CD36 (2-fold), but not GLUT4, content, and concomitantly decreased basal intracellular membrane GLUT4 and CD36 content (−60% and −62%, respectively), indicating successful CD36 translocation and incomplete GLUT4 translocation. Additionally, endosomal alkalinization elevated basal LCFA uptake (1.4-fold) in a nonadditive manner to insulin/oligomycin, and decreased insulin/oligomycin-stimulated glucose uptake (−32%/−68%). In conclusion, 1) CD36 translocation, just like GLUT4 translocation, is a vesicle-mediated process depending on coat proteins, and 2) GLUT4 and CD36 trafficking are differentially dependent on endosomal pH and actin filaments. The latter conclusion suggests novel strategies to alter cardiac substrate preference as part of metabolic modulation therapy.

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Palmitate- and lipopolysaccharide-activated macrophages evoke contrasting insulin responses in muscle cells

AJP Endocrinology and Metabolism ◽

10.1152/ajpendo.90667.2008 ◽

2009 ◽

Vol 296 (1) ◽

pp. E37-E46 ◽

Cited By ~ 42

Author(s):

Victor Samokhvalov ◽

Phillip J. Bilan ◽

Jonathan D. Schertzer ◽

Costin N. Antonescu ◽

Amira Klip

Keyword(s):

Insulin Resistance ◽

Glucose Uptake ◽

Conditioned Medium ◽

Insulin Action ◽

Muscle Cells ◽

Raw 264.7 ◽

Activated Macrophages ◽

Glut4 Translocation ◽

Raw 264.7 Macrophages ◽

Akt Phosphorylation

Factors secreted by macrophages contribute to whole body insulin resistance, acting in part on adipose tissue. Muscle is the major tissue for glucose disposal, but how macrophage-derived factors impact skeletal muscle glucose uptake is unknown, or whether the macrophage environment influences this response. We hypothesized that conditioned medium from macrophages pretreated with palmitate or LPS would directly affect insulin action and glucose uptake in muscle cells. L6-GLUT4 myc myoblasts were exposed to conditioned medium from RAW 264.7 macrophages pretreated with palmitate or LPS. Conditioned medium from palmitate-treated RAW 264.7 macrophages inhibited myoblast insulin-stimulated glucose uptake, GLUT4 translocation, and Akt phosphorylation while activating JNK p38 MAPK, decreasing IκBα, and elevating inflammation markers. Surprisingly, and opposite to its effects on adipose cells, conditioned medium from LPS-treated macrophages stimulated myoblast insulin-stimulated glucose uptake, GLUT4 translocation, and Akt phosphorylation without affecting stress kinases or inflammation indexes. This medium had markedly elevated IL-10 levels, and IL-10, alone, potentiated insulin action in myoblasts and partly reversed the insulin resistance imparted by medium from palmitate-treated macrophages. IL-10 neutralizing antibodies blunted the positive influence of LPS macrophage-conditioned medium. We conclude that myoblasts and adipocytes respond differently to cytokines. Furthermore, depending on their environment, macrophages negatively or positively influence muscle cells. Macrophages exposed to palmitate produce a mixture of proinflammatory cytokines that reduce insulin action in muscle cells; conversely, LPS-activated macrophages increase insulin action, likely via IL-10. Macrophages may be an integral element in glucose homeostasis in vivo, relaying effects of circulating factors to skeletal muscle.

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LMO3 reprograms visceral adipocyte metabolism during obesity

Journal of Molecular Medicine ◽

10.1007/s00109-021-02089-9 ◽

2021 ◽

Author(s):

Gabriel Wagner ◽

Anna Fenzl ◽

Josefine Lindroos-Christensen ◽

Elisa Einwallner ◽

Julia Husa ◽

...

Keyword(s):

Gene Expression ◽

Adipose Tissue ◽

Insulin Sensitivity ◽

Glucose Uptake ◽

Visceral Adipose Tissue ◽

Tissue Expansion ◽

Oxidative Capacity ◽

Glut4 Translocation ◽

Mitochondrial Oxidative Capacity ◽

Visceral Adipose

Abstract Obesity and body fat distribution are important risk factors for the development of type 2 diabetes and metabolic syndrome. Evidence has accumulated that this risk is related to intrinsic differences in behavior of adipocytes in different fat depots. We recently identified LIM domain only 3 (LMO3) in human mature visceral adipocytes; however, its function in these cells is currently unknown. The aim of this study was to determine the potential involvement of LMO3-dependent pathways in the modulation of key functions of mature adipocytes during obesity. Based on a recently engineered hybrid rAAV serotype Rec2 shown to efficiently transduce both brown adipose tissue (BAT) and white adipose tissue (WAT), we delivered YFP or Lmo3 to epididymal WAT (eWAT) of C57Bl6/J mice on a high-fat diet (HFD). The effects of eWAT transduction on metabolic parameters were evaluated 10 weeks later. To further define the role of LMO3 in insulin-stimulated glucose uptake, insulin signaling, adipocyte bioenergetics, as well as endocrine function, experiments were conducted in 3T3-L1 adipocytes and newly differentiated human primary mature adipocytes, engineered for transient gain or loss of LMO3 expression, respectively. AAV transduction of eWAT results in strong and stable Lmo3 expression specifically in the adipocyte fraction over a course of 10 weeks with HFD feeding. LMO3 expression in eWAT significantly improved insulin sensitivity and healthy visceral adipose tissue expansion in diet-induced obesity, paralleled by increased serum adiponectin. In vitro, LMO3 expression in 3T3-L1 adipocytes increased PPARγ transcriptional activity, insulin-stimulated GLUT4 translocation and glucose uptake, as well as mitochondrial oxidative capacity in addition to fatty acid oxidation. Mechanistically, LMO3 induced the PPARγ coregulator Ncoa1, which was required for LMO3 to enhance glucose uptake and mitochondrial oxidative gene expression. In human mature adipocytes, LMO3 overexpression promoted, while silencing of LMO3 suppressed mitochondrial oxidative capacity. LMO3 expression in visceral adipose tissue regulates multiple genes that preserve adipose tissue functionality during obesity, such as glucose metabolism, insulin sensitivity, mitochondrial function, and adiponectin secretion. Together with increased PPARγ activity and Ncoa1 expression, these gene expression changes promote insulin-induced GLUT4 translocation, glucose uptake in addition to increased mitochondrial oxidative capacity, limiting HFD-induced adipose dysfunction. These data add LMO3 as a novel regulator improving visceral adipose tissue function during obesity. Key messages LMO3 increases beneficial visceral adipose tissue expansion and insulin sensitivity in vivo. LMO3 increases glucose uptake and oxidative mitochondrial activity in adipocytes. LMO3 increases nuclear coactivator 1 (Ncoa1). LMO3-enhanced glucose uptake and mitochondrial gene expression requires Ncoa1.

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β-Sitosterol-D-Glucopyranoside Mimics Estrogenic Properties and Stimulates Glucose Utilization in Skeletal Muscle Cells

Molecules ◽

10.3390/molecules26113129 ◽

2021 ◽

Vol 26 (11) ◽

pp. 3129

Author(s):

Jyotsana Pandey ◽

Kapil Dev ◽

Sourav Chattopadhyay ◽

Sleman Kadan ◽

Tanuj Sharma ◽

...

Keyword(s):

Skeletal Muscle ◽

Glucose Uptake ◽

Glucose Utilization ◽

Diabetes Management ◽

Expression System ◽

Muscle Cells ◽

Skeletal Muscle Cells ◽

Cell Periphery ◽

Glut4 Translocation ◽

In Silico Docking

Estrogenic molecules have been reported to regulate glucose homeostasis and may be beneficial for diabetes management. Here, we investigated the estrogenic effect of β-sitosterol-3-O-D-glucopyranoside (BSD), isolated from the fruits of Cupressus sempervirens and monitored its ability to regulate glucose utilization in skeletal muscle cells. BSD stimulated ERE-mediated luciferase activity in both ERα and ERβ-ERE luc expression system with greater response through ERβ in HEK-293T cells, and induced the expression of estrogen-regulated genes in estrogen responsive MCF-7 cells. In silico docking and molecular interaction studies revealed the affinity and interaction of BSD with ERβ through hydrophobic interaction and hydrogen bond pairing. Furthermore, prolonged exposure of L6-GLUT4myc myotubes to BSD raised the glucose uptake under basal conditions without affecting the insulin-stimulated glucose uptake, the effect associated with enhanced translocation of GLUT4 to the cell periphery. The BSD-mediated biological response to increase GLUT4 translocation was obliterated by PI-3-K inhibitor wortmannin, and BSD significantly increased the phosphorylation of AKT (Ser-473). Moreover, BSD-induced GLUT4 translocation was prevented in the presence of fulvestrant. Our findings reveal the estrogenic activity of BSD to stimulate glucose utilization in skeletal muscle cells via PI-3K/AKT-dependent mechanism.

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Time course of insulin resistance associated with feeding dogs a high-fat diet

AJP Endocrinology and Metabolism ◽

10.1152/ajpendo.1997.272.1.e147 ◽

1997 ◽

Vol 272 (1) ◽

pp. E147-E154 ◽

Cited By ~ 13

Author(s):

A. P. Rocchini ◽

P. Marker ◽

T. Cervenka

Keyword(s):

Insulin Resistance ◽

Blood Pressure ◽

Glucose Uptake ◽

Dose Response ◽

High Fat Diet ◽

Time Course ◽

Rapid Development ◽

Diet Group ◽

Whole Body ◽

High Fat

The current study evaluated both the time course of insulin resistance associated with feeding dogs a high-fat diet and the relationship between the development of insulin resistance and the increase in blood pressure that also occurs. Twelve adult mongrel dogs were chronically instrumented and randomly assigned to either a control diet group (n = 4) or a high-fat diet group (n = 8). Insulin resistance was assessed by a weekly, single-dose (2 mU.kg-1.min-1) euglycemic-hyperinsulinemic clamp on all dogs. Feeding dogs a high-fat diet was associated with a 3.7 +/- 0.5 kg increase in body weight, a 20 +/- 4 mmHg increase in mean blood pressure, a reduction in insulin-mediated glucose uptake [(in mumol-kg-1.min-1) decreasing from 72 +/- 6 before to 49 +/- 7 at 1 wk, 29 +/- 3 at 3 wk, and 30 +/- 2 at 6 wk of the high-fat diet, P < 0.01]. and a reduced insulin-mediated increase in cardiac output. In eight dogs (4 high fat and 4 control), the dose-response relationship of insulin-induced glucose uptake also was studied. The whole body glucose uptake dose-response curve was shifted to the right, and the rate of maximal whole body glucose uptake was significantly decreased (P < 0.001). Finally, we observed a direct relationship between the high-fat diet-induced weekly increase in mean arterial pressure and the degree to which insulin resistance developed. In summary, the current study documents that feeding dogs a high-fat diet causes the rapid development of insulin resistance that is the result of both a reduced sensitivity and a reduced responsiveness to insulin.

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