Exposures to subtoxic concentrations of iAs or MAs inhibit GLUT4 association with the plasma membrane of insulin-activated adipocytes

<p><b>Copyright information:</b></p><p>Taken from "Molecular Mechanisms of the Diabetogenic Effects of Arsenic: Inhibition of Insulin Signaling by Arsenite and Methylarsonous Acid"</p><p></p><p>Environmental Health Perspectives 2007;115(5):734-742.</p><p>Published online 29 Jan 2007</p><p>PMCID:PMC1867998.</p><p>This is an Open Access article: verbatim copying and redistribution of this article are permitted in all media for any purpose, provided this notice is preserved along with the article's original DOI</p> Immunofluorescent images of GLUT4 in plasma membrane lawns isolated from control (untreated) 3T3-L1 adipocytes before () and after activation () with insulin and from insulin-activated adipocytes treated for 4 hr with 50 μM iAs () or 2 μM MAs (). Adipocytes were fixed and sonicated to prepare plasma membrane lawns. GLUT4 was labeled with an anti-GLUT4 antibody and visualized with a fluorescent secondary antibody. Representative fields of two independent experiments are shown. Bars = 10 μm

Molecular Mechanisms of the Diabetogenic Effects of Arsenic: Inhibition of Insulin Signaling by Arsenite and Methylarsonous Acid-1

<p><b>Copyright information:</b></p><p>Taken from "Molecular Mechanisms of the Diabetogenic Effects of Arsenic: Inhibition of Insulin Signaling by Arsenite and Methylarsonous Acid"</p><p></p><p>Environmental Health Perspectives 2007;115(5):734-742.</p><p>Published online 29 Jan 2007</p><p>PMCID:PMC1867998.</p><p>This is an Open Access article: verbatim copying and redistribution of this article are permitted in all media for any purpose, provided this notice is preserved along with the article's original DOI</p

Molecular Mechanisms of the Diabetogenic Effects of Arsenic: Inhibition of Insulin Signaling by Arsenite and Methylarsonous Acid-6

<p><b>Copyright information:</b></p><p>Taken from "Molecular Mechanisms of the Diabetogenic Effects of Arsenic: Inhibition of Insulin Signaling by Arsenite and Methylarsonous Acid"</p><p></p><p>Environmental Health Perspectives 2007;115(5):734-742.</p><p>Published online 29 Jan 2007</p><p>PMCID:PMC1867998.</p><p>This is an Open Access article: verbatim copying and redistribution of this article are permitted in all media for any purpose, provided this notice is preserved along with the article's original DOI</p

Molecular Mechanisms of the Diabetogenic Effects of Arsenic: Inhibition of Insulin Signaling by Arsenite and Methylarsonous Acid-0

<p><b>Copyright information:</b></p><p>Taken from "Molecular Mechanisms of the Diabetogenic Effects of Arsenic: Inhibition of Insulin Signaling by Arsenite and Methylarsonous Acid"</p><p></p><p>Environmental Health Perspectives 2007;115(5):734-742.</p><p>Published online 29 Jan 2007</p><p>PMCID:PMC1867998.</p><p>This is an Open Access article: verbatim copying and redistribution of this article are permitted in all media for any purpose, provided this notice is preserved along with the article's original DOI</p

Exposures to subtoxic concentrations of iAs or MAs do not affect insulin signal mediators that regulate PIP levels in insulin-activated adipocytes

<p><b>Copyright information:</b></p><p>Taken from "Molecular Mechanisms of the Diabetogenic Effects of Arsenic: Inhibition of Insulin Signaling by Arsenite and Methylarsonous Acid"</p><p></p><p>Environmental Health Perspectives 2007;115(5):734-742.</p><p>Published online 29 Jan 2007</p><p>PMCID:PMC1867998.</p><p>This is an Open Access article: verbatim copying and redistribution of this article are permitted in all media for any purpose, provided this notice is preserved along with the article's original DOI</p> () Immunoblot analyses of the activated PI-3K, total PTEN, and phosphorylated PTEN (Ser380) in control 3T3-L1 adipocytes before or after activation with insulin and in insulin-activated adipocytes treated for 4 hr with 50 μM iAs or 2 μM MAs. Activated PI-3K was immunoprecipitated from control and exposed cells with an anti-phospho-Tyr (PY20) antibody and immunoblotted with an antibody against the regulatory (p85) subunit. Representative blots of three independent experiments are shown. () The ratio of phosphorylated PTEN (Ser380) to total PTEN expressed as a percent of the ratio found in control adipocytes before activation with insulin. Each value represents the mean ± SD; = 3 experiments

Molecular Mechanisms of the Diabetogenic Effects of Arsenic: Inhibition of Insulin Signaling by Arsenite and Methylarsonous Acid-8

<p><b>Copyright information:</b></p><p>Taken from "Molecular Mechanisms of the Diabetogenic Effects of Arsenic: Inhibition of Insulin Signaling by Arsenite and Methylarsonous Acid"</p><p></p><p>Environmental Health Perspectives 2007;115(5):734-742.</p><p>Published online 29 Jan 2007</p><p>PMCID:PMC1867998.</p><p>This is an Open Access article: verbatim copying and redistribution of this article are permitted in all media for any purpose, provided this notice is preserved along with the article's original DOI</p

Four-hour exposures to subtoxic concentrations of iAs or MAs do not increase DNA fragmentation in cultured adipocytes

<p><b>Copyright information:</b></p><p>Taken from "Molecular Mechanisms of the Diabetogenic Effects of Arsenic: Inhibition of Insulin Signaling by Arsenite and Methylarsonous Acid"</p><p></p><p>Environmental Health Perspectives 2007;115(5):734-742.</p><p>Published online 29 Jan 2007</p><p>PMCID:PMC1867998.</p><p>This is an Open Access article: verbatim copying and redistribution of this article are permitted in all media for any purpose, provided this notice is preserved along with the article's original DOI</p> DNA fragmentation was measured by TUNEL in 3T3-L1 adipocytes treated with 50 μM iAs or 2 μM MAs for 4, 24, 48, and 72 hr. Untreated adipocytes were used as controls. Color images show green fluorescein signal of fragmented DNA in apoptotic cells. Gray-scale images illustrate the corresponding cell morphology. Representative fields of two independent experiments are shown. Bars = 40 μm

Figure 3

<p>Effect of temperature on aggregation. <b>A)</b> Light scattered intensity at 90° angle registered during the temperature scan. Data relative to different proteins are normalized by dividing for the respective initial values of scattered intensity. <b>B)</b> Weight-average radius of the largest species, as obtained by CONTIN analysis <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0000111#pone.0000111-Provencher1" target="_blank">[38]</a>, followed during the temperature scan.</p

Figure 1

<p>Comparison of the intensity-weighted size distribution of GST (black line), GST-Q22 (red line) and GST-Q41 (green line) at 90° scattering angle. The measurements were carried out on 20 µM protein samples and at 20°C.</p

Figure 2

<p>Effect of an antioxidant on aggregation. <b>A)</b> Comparison between the intensity-weighted size distributions obtained in the absence and in the presence of DTT. <b>B)</b> Time course of light scattered intensity at 90° angle upon addition of DTT to fresh protein samples. GST, GST-Q22 and GST-Q41 are shown using black, red and green lines, respectively. The measurements shown were carried out at 20°C using 20 µM samples.</p