Translocation factor (TF) of leaf, new shoots and wood in three varieties of <i>S. integra</i> for the different Pb treatment.

<p>(A) Dahongtou. (B) Weishanhu. (C) Yizhibi.</p

Tolerance index (TI) in three <i>S. integra</i> varieties after 14 days of exposure to increasing concentrations of Pb.

<p>Values are mean ± S.D. (n = 6), and data with different letters in the same column indicate a significant difference at <i>P</i><0.05 according to Fisher's LSD test.</p><p>Tolerance index (TI) in three <i>S. integra</i> varieties after 14 days of exposure to increasing concentrations of Pb.</p

Root characteristics of three <i>S. integra</i> varieties exposed to different Pb concentrations for 14 days.

<p>(A) Total root length. (B) Surface area. (C) Root volume. (D) Average diameter. Data points and error bars represent means ± S.D. of three replicates (<i>n</i> = 3). Different letters indicate significant differences (<i>P</i><0.05) across the treatments according to Fisher's LSD test.</p

Average Pb concentrations (mg kg⁻¹) in dry plant tissues of <i>S. integra</i> exposed to various Pb treatments for 14 days.

<p>Values are mean ± S.D. (n = 6), and data with different letters in the same column indicate a significant difference at <i>P</i><0.05 according to Fisher's LSD test.</p><p>Average Pb concentrations (mg kg⁻¹) in dry plant tissues of <i>S. integra</i> exposed to various Pb treatments for 14 days.</p

Two-way ANOVA analysis for Pb concent in root and the aboveground tissues.

<p>Two-way ANOVA analysis for Pb concent in root and the aboveground tissues.</p

Chlorophyll Concentration Index (CCI) of leaves of three varieties of <i>S. integra</i> grown in various Pb concentrations for 14 days.

<p>Values are mean ± S.D. (n = 6), and data with different letters in the same column indicate a significant difference at <i>P</i><0.05 according to Fisher's LSD test.</p><p>Chlorophyll Concentration Index (CCI) of leaves of three varieties of <i>S. integra</i> grown in various Pb concentrations for 14 days.</p

Lead content (mg plant⁻¹) in root and aboveground tissue (wood, new shoots, and leaves) of three <i>S. integra</i> varieties exposed to different Pb concentrations for 14 days.

<p>Values are mean ± S.D. (n = 6), and data with different letters within the same column indicate a significant difference at <i>P</i><0.05 according to Fisher's LSD test.</p><p>Lead content (mg plant⁻¹) in root and aboveground tissue (wood, new shoots, and leaves) of three <i>S. integra</i> varieties exposed to different Pb concentrations for 14 days.</p

Calculated EC50 toxicity thresholds, models, R and P. for roots and the aboveground tissues (combined wood, new shoots and leaves) of three willow varieties exposed to increasing levels of lead.

<p>Calculated EC50 toxicity thresholds, models, R and P. for roots and the aboveground tissues (combined wood, new shoots and leaves) of three willow varieties exposed to increasing levels of lead.</p

Metformin suppresses retinal angiogenesis and inflammation <i>in vitro</i> and <i>in vivo</i>

<div><p>The oral anti-diabetic drug metformin has been found to reduce cardiovascular complications independent of glycemic control in diabetic patients. However, its role in diabetic retinal microvascular complications is not clear. This study is to investigate the effects of metformin on retinal vascular endothelium and its possible mechanisms, regarding two major pathogenic features of diabetic retinopathy: angiogenesis and inflammation. In human retinal vascular endothelial cell culture, metformin inhibited various steps of angiogenesis including endothelial cell proliferation, migration, and tube formation in a dose-dependent manner. Its anti-angiogenic activity was confirmed <i>in vivo</i> that metformin significantly reduced spontaneous intraretinal neovascularization in a very-low-density lipoprotein receptor knockout mutant mouse (<i>p</i><0.05). Several inflammatory molecules upregulated by tumor necrosis factor-α in human retinal vascular endothelial cells were markedly reduced by metformin, including nuclear factor kappa B p65 (NFκB p65), intercellular adhesion molecule-1 (ICAM-1), monocyte chemotactic protein-1 (MCP-1), and interleukin-8 (IL-8). Further, metformin significantly decreased retinal leukocyte adhesion (<i>p</i><0.05) in streptozotocin-induced diabetic mice. Activation of AMP-activated protein kinase was found to play a partial role in the suppression of ICAM-1 and MCP-1 by metformin, but not in those of NFκB p65 and IL-8. Our findings support the notion that metformin has considerable anti-angiogenic and anti-inflammatory effects on retinal vasculature. Metformin could be potentially used for the purpose of treating diabetic retinopathy in addition to blood glucose control in diabetic patients.</p></div

AMPK inhibition in metformin’s effects on NFκB, MCP-1, IL-8 and ICAM-1 in hRVECs.

<p>HRVECs were pretreated with metformin, then exposed to TNFα as described in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0193031#pone.0193031.g003" target="_blank">Fig 3</a>. A selective AMPK inhibitor, compound C, was co-administrated to evaluate the role of AMPK signaling in metformin’s influence on hRVECs. <b>(A)</b> Representative images and densitometric analysis of <a target="_blank">p</a>AMPKα immunoblot in hRVECs. TNFα markedly reduced the level of pAMPKα, which was impeded by pretreatment of metformin dose-dependently. <b>(B)</b> Western blot of NFkB p65 and <b>(C)</b> ELISA of IL-8 revealed no obvious changes were caused by addition of compound C in metformin regiment in the presence of TNFα. <b>(D)</b> Western blot of ICAM-1 and <b>(E)</b> ELISA of MCP-1 showed that compound C significantly blocked the inhibition of ICAM-1 and MCP-1 by metformin. Data were normalized to control (without metformin and TNFα) and presented as mean ± SEM (n = 3). ^# <i>p</i> < 0.05 versus control. * <i>p</i> < 0.05 versus TNFα-only group.</p