scholarly journals An Explanation for the Adiponectin Paradox

2021 ◽  
Vol 14 (12) ◽  
pp. 1266
Author(s):  
Hans O. Kalkman
Keyword(s):  
Insulin Resistance ◽  
Signal Transduction ◽  
Insulin Sensitivity ◽  
Phospholipase D ◽  
Functional Consequence ◽  
Glycosyl Phosphatidylinositol ◽  
Paradoxical Situation ◽  
Hydrolysis Of ◽  
Circulating Levels ◽  
Sensitivity Functional

The adipokine adiponectin improves insulin sensitivity. Functional signal transduction of adiponectin requires at least one of the receptors AdipoR1 or AdipoR2, but additionally the glycosyl phosphatidylinositol-anchored molecule, T-cadherin. Overnutrition causes a reduction in adiponectin synthesis and an increase in the circulating levels of the enzyme glycosyl phosphatidylinositol-phospholipase D (GPI-PLD). GPI-PLD promotes the hydrolysis of T-cadherin. The functional consequence of T-cadherin hydrolysis is a reduction in adiponectin sequestration by responsive tissues, an augmentation of adiponectin levels in circulation and a (further) reduction in signal transduction. This process creates the paradoxical situation that adiponectin levels are augmented, whereas the adiponectin signal transduction and insulin sensitivity remain strongly impaired. Although both hypoadiponectinemia and hyperadiponectinemia reflect a situation of insulin resistance, the treatments are likely to be different.

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 Organization and alternative splicing of the murine phospholipase D2 gene

1998 ◽  
Vol 331 (3) ◽  
pp. 845-851 ◽  
Author(s):  
Olga E. REDINA ◽  
Michael A. FROHMAN
Keyword(s):  
Signal Transduction ◽  
Alternative Splicing ◽  
Phospholipase D ◽  
Untranslated Region ◽  
Genomic Organization ◽  
Proximal Promoter ◽  
Promoter Sequences ◽  
Phospholipase D2 ◽  
Alternatively Spliced ◽  
Hydrolysis Of

Phospholipase D (PLD) catalyses the hydrolysis of phosphatidylcholine, generating phosphatidic acid and choline. Mammalian PLD activity derives from a family of membrane-associated enzymes that are activated by a wide variety of signal transduction events. cDNA species encoding human, mouse and rat PLD1 and PLD2 have recently been reported. In this study we undertook to determine the organization of the mouse PLD2 gene. We report that the gene spans 17.1 kb and contains 25 exons. Mouse PLD2 is notable for a relatively GC-rich and large 5´ untranslated region. Proximal promoter sequences upstream of the first exon contain several consensus SP1 sequences (GGGCGG) but lack TATA and CAAT boxes. Finally, alternatively spliced cDNA species identified for PLD1 and PLD2 are discussed in the context of the PLD2 genomic organization.

Insulin does not induce the hydrolysis of a glycosyl phosphatidylinositol in rat fetal hepatocytes

Diabetes ◽  
1993 ◽  
Vol 42 (9) ◽  
pp. 1262-1272 ◽  
Author(s):  
J. M. Ruiz-Albusac ◽  
J. A. Zueco ◽  
E. Velazquez ◽  
E. Blazquez
Keyword(s):  
Glycosyl Phosphatidylinositol ◽  
Fetal Hepatocytes ◽  
Hydrolysis Of

Magnesium intake, insulin resistance and markers of endothelial function among women

2021 ◽  
pp. 1-9
Author(s):  
Narges Ghorbani Bavani ◽  
Parvane Saneei ◽  
Ammar Hassanzadeh Keshteli ◽  
Ahmadreza Yazdannik ◽  
Ebrahim Falahi ◽  
...  
Keyword(s):  
Insulin Resistance ◽  
Insulin Sensitivity ◽  
Endothelial Dysfunction ◽  
Endothelial Function ◽  
Adhesion Molecule ◽  
Cell Function ◽  
Intercellular Adhesion Molecule ◽  
Model Assessment ◽  
Serum Concentrations ◽  
Homeostasis Model Assessment

Abstract Objective: We investigated the association of dietary Mg intake with insulin resistance and markers of endothelial function among Iranian women. Design: A cross-sectional study. Setting: Usual dietary intakes were assessed using a validated FFQ. Dietary Mg intake was calculated by summing up the amount of Mg in all foods. A fasting blood sample was taken to measure serum concentrations of glycemic indices (fasting plasma glucose and insulin) and endothelial function markers (E-selectin, soluble intercellular adhesion molecule-1 (sICAM-1) and soluble vascular cell adhesion molecule-1). Insulin resistance and sensitivity were estimated using the Homeostasis Model Assessment-Insulin Resistance (HOMA-IR), Homeostasis Model Assessment β-cell function (HOMA-β) and quantitative insulin sensitivity check index (QUICKI). Participants: Iranian female nurses (n 345) selected by a multistage cluster random sampling method. Results: The Mg intake across energy-adjusted quartiles was 205 (se 7), 221·4 (se 8), 254·3 (se 7) and 355·2 (se 9) mg/d, respectively. After adjustments for potential confounders, QUICKI level was significantly different across quartiles of Mg intake (Q1: 0·34 (se 0·02), Q2: 0·36 (se 0·01), Q3: 0·40 (se 0·01), and Q4: 0·39 (se 0·02), P = 0·02); however, this association disappeared after considering markers of endothelial function, indicating that this relation might be mediated through endothelial dysfunction. After controlling for all potential confounders, Mg intake was inversely, but not significantly, associated with serum concentrations of sICAM (Q1: 239 (se 17), Q2: 214 (se 12), Q3: 196 (se 12), and Q4: 195 (se 17), P = 0·29). There was no other significant association between dietary Mg intake and other indicators of glucose homoeostasis or endothelial markers. Conclusions: Higher dietary Mg intake was associated with better insulin sensitivity in Iranian females. This linkage was mediated through reduced endothelial dysfunction.

scholarly journals The possible role of Interleukin-6 as a regulator of insulin sensitivity in patients with neuromyelitis optica spectrum disorder

BMC Neurology ◽  
2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Zhila Maghbooli ◽  
Abdorreza Naser Moghadasi ◽  
Nasim Rezaeimanesh ◽  
Abolfazl Omidifar ◽  
Tarlan Varzandi ◽  
...  
Keyword(s):  
Insulin Sensitivity ◽  
Neuromyelitis Optica ◽  
Serum Levels ◽  
Spectrum Disorder ◽  
Control Group ◽  
Neuromyelitis Optica Spectrum Disorder ◽  
Downstream Signaling ◽  
Reduce Insulin Sensitivity ◽  
Circulating Levels

Abstract Background Neuromyelitis optica spectrum disorder (NMOSD) is associated with inflammatory mediators that may also trigger downstream signaling pathways leading to reduce insulin sensitivity. Methods We aimed to determine the risk association of hyperinsulinemia in NMOSD patients with seropositive AQP4-IgG and the serum levels of interleukin (IL)-6 and IL-17A compared with the control group. Serum levels of metabolic (Insulin, Fasting Blood Sugar (FBS), lipid profile) and inflammatory (IL-6 and IL-17) markers were assessed in 56 NMOSD patients and 100 controls. Results Hyperinsulinemia was more prevalent in NMOSD patients independent of age, sex and body mass index (BMI) (48.2% vs. 26%, p = 0.005) compared to control group. After adjusting age, sex and BMI, there was significant association between lower insulin sensitivity (IS) and NMOSD risk (95% CI: Beta = 0.73, 0.62 to 0.86, p = 0.0001). Circulating levels of IL-6 and IL-17 were higher in NMOSD patients, and only IL-6 had an effect modifier for the association between lower insulin sensitivity and NMOSD risk. Conclusions Our data suggests that inflammatory pathogenesis of NMOSD leads to hyperinsulinemia and increases the risk of insulin resistance.

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