scholarly journals Vasodilator-stimulated phosphoprotein protects against vascular inflammation and insulin resistance

2014 ◽  
Vol 307 (7) ◽  
pp. E571-E579 ◽  
Author(s):  
Andrew M. Cheng ◽  
Norma Rizzo-DeLeon ◽  
Carole L. Wilson ◽  
Woo Je Lee ◽  
Sanshiro Tateya ◽  
...  
Keyword(s):  
Insulin Resistance ◽  
Bone Marrow ◽  
Insulin Sensitivity ◽  
Vascular Tissue ◽  
Vascular Inflammation ◽  
Physiological Role ◽  
Whole Body ◽  
Aortic Tissue ◽  
Protective Effects ◽  
Downstream Mediator

Among the pleotropic effects of endothelial nitric oxide (NO) is protection against vascular inflammation during high-fat diet (HFD) feeding. The current work investigated the role of the enzyme vasodilatory-stimulated phosphoprotein (VASP) as a downstream mediator of the anti-inflammatory effect of NO signaling in vascular tissue. Relative to mice fed a low-fat diet (LFD), levels of VASP Ser239 phosphorylation, a marker of VASP activation, were dramatically reduced in aortic tissue of mice with obesity induced by consuming a HFD. As reported previously, the effect of the HFD was associated with increased aortic inflammation, as measured by increased NF-κB-dependent gene expression, and reduced vascular insulin sensitivity (including insulin-stimulated phosphorylation of eNOS and Akt). These effects of the HFD were recapitulated by VASP knockout, implying a physiological role for VASP to constrain inflammatory signaling and thereby maintain vascular insulin sensitivity. Conversely, overexpression of VASP in endothelial cells blocked inflammation and insulin resistance induced by palmitate. The finding that transplantation of bone marrow from VASP-deficient donors into normal recipients does not recapitulate the vascular effects of whole body VASP deficiency suggests that the protective effects of this enzyme are not mediated in immune or other bone marrow-derived cells. These studies implicate VASP as a downstream mediator of the NO/cGMP pathway that is both necessary and sufficient to protect against vascular inflammation and insulin resistance. As such, this work identifies VASP as a potential therapeutic target in the treatment of obesity-related vascular dysfunction.

scholarly journals Astragalus Polysaccharide Suppresses Skeletal Muscle Myostatin Expression in Diabetes: Involvement of ROS-ERK and NF-κB Pathways

2013 ◽  
Vol 2013 ◽  
pp. 1-10 ◽  
Author(s):  
Min Liu ◽  
Jian Qin ◽  
Yarong Hao ◽  
Min Liu ◽  
Jun Luo ◽  
...  
Keyword(s):  
Insulin Resistance ◽  
Skeletal Muscle ◽  
Insulin Sensitivity ◽  
Saturated Acid ◽  
C2c12 Cells ◽  
Whole Body ◽  
Protective Effects ◽  
Kkay Mice ◽  
Astragalus Polysaccharide

Objective. The antidiabetes drug astragalus polysaccharide (APS) is capable of increasing insulin sensitivity in skeletal muscle and improving whole-body glucose homeostasis. Recent studies suggest that skeletal muscle secreted growth factor myostatin plays an important role in regulating insulin signaling and insulin resistance. We hypothesized that regulation of skeletal muscle myostatin expression may be involved in the improvement of insulin sensitivity by APS.Methods. APS was administered to 13-week-old diabetic KKAy and nondiabetic C57BL/6J mice for 8 weeks. Complementary studies examined APS effects on the saturated acid palmitate-induced insulin resistance and myostatin expression in C2C12 cells.Results. APS treatment ameliorated hyperglycemia, hyperlipidemia, and insulin resistance and decreased the elevation of myostatin expression and malondialdehyde production in skeletal muscle of noninsulin-dependent diabetic KKAy mice. In C2C12 cells in vitro, saturated acid palmitate-induced impaired glucose uptake, overproduction of ROS, activation of extracellular regulated protein kinases (ERK), and NF-κB were partially restored by APS treatment. The protective effects of APS were mimicked by ERK and NF-κB inhibitors, respectively.Conclusion. Our study demonstrates elevated myostatin expression in skeletal muscle of type 2 diabetic KKAy mice and in cultured C2C12 cells exposed to palmitate. APS is capable of improving insulin sensitivity and decreasing myostatin expression in skeletal muscle through downregulating ROS-ERK-NF-κB pathway.

scholarly journals Bone Marrow Metabolism Is Impaired in Insulin Resistance and Improves After Exercise Training

2020 ◽  
Vol 105 (12) ◽  
pp. e4290-e4303
Author(s):  
Ronja Ojala ◽  
Kumail K Motiani ◽  
Kaisa K Ivaska ◽  
Milja Arponen ◽  
Jari-Joonas Eskelinen ◽  
...  
Keyword(s):  
Insulin Resistance ◽  
Bone Marrow ◽  
Insulin Sensitivity ◽  
Exercise Training ◽  
Bone Turnover ◽  
Whole Body ◽  
Moderate Intensity ◽  
Anatomical Location ◽  
Acid Uptake ◽  
Mineral Density

Abstract Context Exercise training improves bone mineral density, but little is known about the effects of training on bone marrow (BM) metabolism. BM insulin sensitivity has been suggested to play an important role in bone health and whole-body insulin sensitivity. Objective To study the effects of exercise training on BM metabolism. Design Randomized controlled trial. Setting Clinical research center. Participants Sedentary healthy (n = 28, 40–55 years, all males) and insulin resistant (IR) subjects (n = 26, 43–55 years, males/females 16/10) Intervention Two weeks of sprint interval training or moderate-intensity continuous training Main outcome measures We measured femoral, lumbar, and thoracic BM insulin-stimulated glucose uptake (GU) and fasting free fatty acid uptake (FFAU) using positron-emission tomography and bone turnover markers from plasma. Results At baseline, GU was highest in lumbar, followed by thoracic, and lowest in femoral BM (all Ps < 0.0001). FFAU was higher in lumbar and thoracic than femoral BM (both Ps < 0.0001). BM FFAU and femoral BM GU were higher in healthy compared to IR men and in females compared to males (all Ps < 0.05). Training increased femoral BM GU similarly in all groups and decreased lumbar BM FFAU in males (all Ps < 0.05). Osteocalcin and PINP were lower in IR than healthy men and correlated positively with femoral BM GU and glycemic status (all Ps < 0.05). Conclusions BM metabolism differs regarding anatomical location. Short-term training improves BM GU and FFAU in healthy and IR subjects. Bone turnover rate is decreased in insulin resistance and associates positively with BM metabolism and glycemic control. Clinical Trial Registration Number NCT01344928.

scholarly journals Insulin sensitizers prevent fine particulate matter-induced vascular insulin resistance and changes in endothelial progenitor cell homeostasis

2016 ◽  
Vol 310 (11) ◽  
pp. H1423-H1438 ◽  
Author(s):  
Petra Haberzettl ◽  
James P. McCracken ◽  
Aruni Bhatnagar ◽  
Daniel J. Conklin
Keyword(s):  
Insulin Resistance ◽  
Bone Marrow ◽  
Particulate Matter ◽  
Insulin Sensitivity ◽  
Ambient Air ◽  
Air Pollutant ◽  
Ambient Air Pollution ◽  
Endothelial Progenitor ◽  
Insulin Sensitizer ◽  
Circulating Levels

Exposure to fine particular matter (PM2.5) increases the risk of developing cardiovascular disease and Type 2 diabetes. Because blood vessels are sensitive targets of air pollutant exposure, we examined the effects of concentrated ambient PM2.5 (CAP) on vascular insulin sensitivity and circulating levels of endothelial progenitor cells (EPCs), which reflect cardiovascular health. We found that CAP exposure for 9 days decreased insulin-stimulated Akt phosphorylation in the aorta of mice maintained on control diet. This change was accompanied by the induction of IL-1β and increases in the abundance of cleaved IL-18 and p10 subunit of Casp-1, consistent with the activation of the inflammasome pathway. CAP exposure also suppressed circulating levels of EPCs (Flk-1+/Sca-1+ cells), while enhancing the bone marrow abundance of these cells. Although similar changes in vascular insulin signaling and EPC levels were observed in mice fed high-fat diet, CAP exposure did not exacerbate diet-induced changes in vascular insulin resistance or EPC homeostasis. Treatment with an insulin sensitizer, metformin or rosiglitazone, prevented CAP-induced vascular insulin resistance and NF-κB and inflammasome activation and restored peripheral blood and bone marrow EPC levels. These findings suggest that PM2.5 exposure induces diet-independent vascular insulin resistance and inflammation and prevents EPC mobilization, and that this EPC mobilization defect could be mediated by vascular insulin resistance. Impaired vascular insulin sensitivity may be an important mechanism underlying PM2.5-induced vascular injury, and pharmacological sensitization to insulin action could potentially prevent deficits in vascular repair and mitigate vascular inflammation due to exposure to elevated levels of ambient air pollution. Listen to this article's corresponding podcast at http://ajpheart.podbean.com/e/particulate-matter-induced-vascular-insulin-resistance/ .

scholarly journals Hepatokine ERAP1 impairs skeletal muscle insulin sensitivity via ADRB2/PKA pathway

2020 ◽  
Author(s):  
Feifan Guo ◽  
Yuguo Niu ◽  
Haizhou Jiang ◽  
Hanrui Yin ◽  
Fenfen Wang ◽  
...  
Keyword(s):  
Insulin Resistance ◽  
Skeletal Muscle ◽  
Insulin Sensitivity ◽  
Neutralizing Antibodies ◽  
Leptin Receptor ◽  
Whole Body ◽  
C2c12 Myotubes ◽  
Insulin Resistant ◽  
Skeletal Muscle Insulin Sensitivity ◽  
Pka Pathway

Abstract The current study aimed to investigate the role of endoplasmic reticulum aminopeptidase 1 (ERAP1), a novel hepatokine, in whole-body glucose metabolism. Here, we found that hepatic ERAP1 levels were increased in insulin-resistant leptin-receptor-mutated (db/db) and high-fat diet (HFD)-fed mice. Consistently, hepatic ERAP1 overexpression attenuated skeletal muscle (SM) insulin sensitivity, whereas knockdown ameliorated SM insulin resistance. Furthermore, serum and hepatic ERAP1 levels were positively correlated, and recombinant mouse ERAP1 or conditioned medium with high ERAP1 content (CM-ERAP1) attenuated insulin signaling in C2C12 myotubes, and CM-ERAP1 or HFD-induced insulin resistance was blocked by ERAP1 neutralizing antibodies. Mechanistically, ERAP1 reduced ADRB2 expression and interrupted ADRB2-dependent signaling in C2C12 myotubes. Finally, ERAP1 inhibition via global knockout or the inhibitor thimerosal improved insulin sensitivity. Together, ERAP1 is a hepatokine that impairs SM and whole-body insulin sensitivity, and its inhibition might provide a therapeutic strategy for diabetes, particularly for those with SM insulin resistance.

scholarly journals Treatment with an SSRI antidepressant restores hippocampo-hypothalamic corticosteroid feedback and reverses insulin resistance in low-birth-weight rats

2010 ◽  
Vol 298 (5) ◽  
pp. E920-E929 ◽  
Author(s):  
Esben S. Buhl ◽  
Thomas Korgaard Jensen ◽  
Niels Jessen ◽  
Betina Elfving ◽  
Christian S. Buhl ◽  
...  
Keyword(s):  
Insulin Resistance ◽  
Birth Weight ◽  
Insulin Sensitivity ◽  
Low Birth Weight ◽  
Mrna Expression ◽  
Hpa Axis ◽  
Whole Body ◽  
Oral Glucose ◽  
Red Muscle ◽  
Hpa Axis Activity

Low birth weight (LBW) is associated with type 2 diabetes and depression, which may be related to prenatal stress and insulin resistance as a result of chronic hypothalamic-pituitary-adrenal (HPA) axis hyperactivity. We examined whether treatment with a selective serotonin reuptake inhibitor [escitalopram (ESC)] could downregulate HPA axis activity and restore insulin sensitivity in LBW rats. After 4–5 wk of treatment, ESC-exposed LBW (SSRI-LBW) and saline-treated control and LBW rats (Cx and LBW) underwent an oral glucose tolerance test or a hyperinsulinemic euglycemic clamp to assess whole body insulin sensitivity. Hepatic phospho enolpyruvate carboxykinase (PEPCK) mRNA expression and red skeletal muscle PKB Ser473phosphorylation were used to assess tissue-specific insulin sensitivity. mRNA expression of the hypothalamic mineralocorticoid receptor was fivefold upregulated in LBW ( P < 0.05 vs. Cx), accompanied by increased corticosterone release during restraint stress and total 24-h urinary excretion ( P < 0.05 vs. Cx), whole body insulin resistance ( P < 0.001 vs. Cx), and impaired insulin suppression of hepatic PEPCK mRNA expression ( P < 0.05 vs. Cx). Additionally, there was a tendency for reduced red muscle PKB Ser473phosphorylation. The ESC treatment normalized corticosterone secretion ( P < 0.05 vs. LBW), whole body insulin sensitivity ( P < 0.01) as well as postprandial suppression of hepatic mRNA PEPCK expression ( P < 0.05), and red muscle PKB Ser473phosphorylation ( P < 0.01 vs. LBW). We conclude that these data suggest that the insulin resistance and chronic HPA axis hyperactivity in LBW rats can be reversed by treatment with an ESC, which downregulates HPA axis activity, lowers glucocorticoid exposure, and restores insulin sensitivity in LBW rats.

Improvement in Insulin Sensitivity and Dyslipidemia in Protease Inhibitor-Treated Adult Male Patients After Switch to Atazanavir/Ritonavir

2008 ◽  
Vol 56 (2) ◽  
pp. 539-544 ◽  
Author(s):  
Anthony J. Busti ◽  
Roger Bedimo ◽  
David M. Margolis ◽  
Dana S. Hardin
Keyword(s):  
Insulin Resistance ◽  
Insulin Sensitivity ◽  
Antiretroviral Therapy ◽  
Insulin Dose ◽  
Whole Body ◽  
Euglycemic Clamp ◽  
Viral Loads ◽  
Immunodeficiency Virus ◽  
Fat Redistribution ◽  
Male Patients

BackgroundTreatment of human immunodeficiency virus (HIV) with protease inhibitors (PIs) is associated with insulin resistance, triglyceride-rich dyslipidemia, and fat redistribution. Atazanavir (ATV), a potent once-daily PI, has been recognized for its convenience to patients, and some studies describe improved lipid metabolism. However, its effects on insulin sensitivity have not been elucidated. We conducted this study to test the hypothesis that ATV improves insulin resistance and dyslipidemia.MethodsWe prospectively studied 9 HIV-infected men with dyslipidemia (median age, 53 years; baseline triglyceride level, >200 mg/dL) on stable PI-containing antiretroviral therapy who elected to change PI therapy to ritonavir-boosted ATV therapy, dose of 300/100 mg. We measured insulin resistance at baseline and after 12 weeks of therapy using a hyperinsulinemic euglycemic clamp (insulin dose, 200 mU/m2 minute). Fasting lipid profiles and body composition (whole-body dual energy x-ray absorptiometry) were also measured at baseline and after 12 weeks.ResultsAll 9 patients completed the study and maintained undetectable viral loads (<50 copies/mL) and stable CD4 counts. After 12 weeks, insulin sensitivity significantly improved (+28%; P = 0.008) in all patients. Triglyceride levels also improved.ConclusionsUsing the gold-standard euglycemic clamp, ritonavir-boosted ATV therapy improved PI-induced insulin resistance among dyslipidemic HIV-infected men on PI-based antiretroviral therapy. These findings were not attributable to a change in body weight and provide further evidence for ATV's unique metabolic profile among the PIs.

scholarly journals The tumor suppressor TMEM127 regulates insulin sensitivity in a tissue-specific manner

2019 ◽  
Vol 10 (1) ◽  
Author(s):  
Subramanya Srikantan ◽  
Yilun Deng ◽  
Zi-Ming Cheng ◽  
Anqi Luo ◽  
Yuejuan Qin ◽  
...  
Keyword(s):  
Insulin Resistance ◽  
Insulin Sensitivity ◽  
Tumor Suppressor ◽  
Hepatic Glucose Production ◽  
Glucose Production ◽  
Suppressor Gene ◽  
Nutrient Sensing ◽  
Whole Body ◽  
Insulin Sensitizer

Abstract Understanding the molecular components of insulin signaling is relevant to effectively manage insulin resistance. We investigated the phenotype of the TMEM127 tumor suppressor gene deficiency in vivo. Whole-body Tmem127 knockout mice have decreased adiposity and maintain insulin sensitivity, low hepatic fat deposition and peripheral glucose clearance after a high-fat diet. Liver-specific and adipose-specific Tmem127 deletion partially overlap global Tmem127 loss: liver Tmem127 promotes hepatic gluconeogenesis and inhibits peripheral glucose uptake, while adipose Tmem127 downregulates adipogenesis and hepatic glucose production. mTORC2 is activated in TMEM127-deficient hepatocytes suggesting that it interacts with TMEM127 to control insulin sensitivity. Murine hepatic Tmem127 expression is increased in insulin-resistant states and is reversed by diet or the insulin sensitizer pioglitazone. Importantly, human liver TMEM127 expression correlates with steatohepatitis and insulin resistance. Our results suggest that besides tumor suppression activities, TMEM127 is a nutrient-sensing component of glucose/lipid homeostasis and may be a target in insulin resistance.

Analysis of candidate genes in Polish families with obesity

2004 ◽  
Vol 42 (5) ◽  
Author(s):  
Malgorzata Malczewska-Malec ◽  
Iwona Wybranska ◽  
Iwona Leszczynska-Golabek ◽  
Lukasz Partyka ◽  
Jadwiga Hartwich ◽  
...  
Keyword(s):  
Risk Factors ◽  
Insulin Resistance ◽  
Insulin Sensitivity ◽  
Body Mass ◽  
Tolerance Test ◽  
Whole Body ◽  
Oral Glucose ◽  
Sensitivity Index ◽  
Model Assessment ◽  
The Metabolic Syndrome

AbstractThis study analyzes the relationship between risk factors related to overweight/obesity, insulin resistance, lipid tolerance, hypertension, endothelial function and genetic polymorphisms associated with: i) appetite regulation (leptin, melanocortin-3-receptor (MCR-3), dopamine receptor 2 (D2R)); ii) adipocyte differentiation and insulin sensitivity (peroxisome proliferator-activated receptor-γThe 122 members of 40 obese Caucasian families from southern Poland participated in the study. The genotypes were analyzed by restriction fragment length polymorphism-polymerase chain reaction (RFLP-PCR) or by direct sequencing. Phenotypes related to obesity (body mass index (BMI), fat/lean body mass composition, waist-to-hip ratio (WHR)), fasting lipids, glucose, leptin and insulin, as well as insulin during oral glucose tolerance test (OGTT) (4 points within 2 hours) and during oral lipid tolerance test (OLTT) (5 points within 8 hours) were assessed. The insulin sensitivity indexes: homeostasis model assessment of insulin resistance, whole body insulin sensitivity index, hepatic insulin sensitivity and early secretory response to an oral glucose load (HOMA-IR, ISI-COMP, ISI-HOMA and DELTA) were calculated.The single gene mutations such as CWe conclude that the polymorphisms we investigated were weakly correlated with obesity but significantly modified the risk factors of the metabolic syndrome.

Expression of FOXC2 in adipose and muscle and its association with whole body insulin sensitivity

2004 ◽  
Vol 287 (4) ◽  
pp. E799-E803 ◽  
Author(s):  
Gina B. Di Gregorio ◽  
Rickard Westergren ◽  
Sven Enerback ◽  
Tong Lu ◽  
Philip A. Kern
Keyword(s):  
Insulin Resistance ◽  
Insulin Sensitivity ◽  
Tolerance Test ◽  
Intravenous Glucose Tolerance Test ◽  
Whole Body ◽  
Forkhead Transcription Factor ◽  
Intravenous Glucose ◽  
Insulin Resistant ◽  
Diet Induced Obesity ◽  
Tnf Α

FOXC2 is a winged helix/forkhead transcription factor involved in PKA signaling. Overexpression of FOXC2 in the adipose tissue of transgenic mice protected against diet-induced obesity and insulin resistance. We examined the expression of FOXC2 in fat and muscle of nondiabetic humans with varying obesity and insulin sensitivity. There was no relation between body mass index (BMI) and FOXC2 mRNA in either adipose or muscle. There was a strong inverse relation between adipose FOXC2 mRNA and insulin sensitivity, using the frequently sampled intravenous glucose tolerance test ( r = −0.78, P < 0.001). However, there was no relationship between muscle FOXC2 and any measure of insulin sensitivity. To separate insulin resistance from obesity, we examined FOXC2 expression in pairs of subjects who were matched for BMI but who were discordant for insulin sensitivity. Compared with insulin-sensitive subjects, insulin-resistant subjects had threefold higher levels of adipose FOXC2 mRNA ( P = 0.03). In contrast, muscle FOXC2 mRNA expression was no different between insulin-resistant and insulin-sensitive subjects. There was no association of adipose or muscle FOXC2 mRNA with either circulating or adipose-secreted TNF-α, IL-6, leptin, adiponectin, or non-esterified fatty acids. Thus adipose FOXC2 is more highly expressed in insulin-resistant subjects, and this effect is independent of obesity. This association between FOXC2 and insulin resistance may be related to the role of FOXC2 in PKA signaling.

scholarly journals Short-term interval training alters brain glucose metabolism in subjects with insulin resistance

2017 ◽  
Vol 38 (10) ◽  
pp. 1828-1838 ◽  
Author(s):  
Sanna M Honkala ◽  
Jarkko Johansson ◽  
Kumail K Motiani ◽  
Jari-Joonas Eskelinen ◽  
Kirsi A Virtanen ◽  
...  
Keyword(s):  
Insulin Resistance ◽  
Insulin Sensitivity ◽  
Interval Training ◽  
Insulin Level ◽  
Whole Body ◽  
Moderate Intensity ◽  
Acid Uptake ◽  
Short Term ◽  
Continuous Training ◽  
Sedentary Subjects

Brain insulin-stimulated glucose uptake (GU) is increased in obese and insulin resistant subjects but normalizes after weight loss along with improved whole-body insulin sensitivity. Our aim was to study whether short-term exercise training (moderate intensity continuous training (MICT) or sprint interval training (SIT)) alters substrates for brain energy metabolism in insulin resistance. Sedentary subjects ( n = 21, BMI 23.7–34.3 kg/m2, age 43–55 y) with insulin resistance were randomized into MICT ( n = 11, intensity≥60% of VO2peak) or SIT ( n = 10, all-out) groups for a two-week training intervention. Brain GU during insulin stimulation and fasting brain free fatty acid uptake (FAU) was measured using PET. At baseline, brain GU was positively associated with the fasting insulin level and negatively with the whole-body insulin sensitivity. The whole-body insulin sensitivity improved with both training modes (20%, p = 0.007), while only SIT led to an increase in aerobic capacity (5%, p = 0.03). SIT also reduced insulin-stimulated brain GU both in global cortical grey matter uptake (12%, p = 0.03) and in specific regions ( p < 0.05, all areas except the occipital cortex), whereas no changes were observed after MICT. Brain FAU remained unchanged after the training in both groups. These findings show that short-term SIT effectively decreases insulin-stimulated brain GU in sedentary subjects with insulin resistance.

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