Statistical significance of differences in ²⁰⁷Pb/²⁰⁶Pb for test substance, diet, blood, urine, and feces in different dose groups (n = 6) of respiratory lead exposure.

<p>Note: Difference are significant when <i>p</i><0.05 level.</p>a, b<p>A significant difference with blood and urine, respectively.</p>c, d, e<p>A significant difference with control group, low dose group and medium dose group, respectively.</p>f, g<p>A significant difference with test substance and diet, respectively.</p

Scatter plot of ²⁰⁴Pb/²⁰⁶Pb ratio versus ²⁰⁷Pb/²⁰⁶Pb ratio in different samples.

<p><a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0052462#pone-0052462-g001" target="_blank">Figure 1A</a>. low-dose group. <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0052462#pone-0052462-g001" target="_blank">Figure 1B</a>. medium-dose group. <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0052462#pone-0052462-g001" target="_blank">Figure 1C</a>. high-dose group.</p

The fractional contribution of diet and test substance in different dose group in blood samples.

<p>The fractional contribution of diet and test substance in different dose group in blood samples.</p

Whole-blood Pb concentration versus isotope ratios in blood for experimental dose groups (n = 18).

<p><a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0052462#pone-0052462-g002" target="_blank">Figure 2A</a>. isotope ratio of ²⁰⁷Pb/²⁰⁶Pb. <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0052462#pone-0052462-g002" target="_blank">Figure 2B</a>. isotope ratio of ²⁰⁸Pb/²⁰⁶Pb.</p

Statistical significance of differences in ²⁰⁴Pb/²⁰⁶Pb for test substance, diet, blood, urine, and feces in different dose groups (n = 6) of respiratory lead exposure.

<p>Note: Difference are significant when <i>p</i><0.05 level.</p>a, b<p>A significant difference with blood and urine, respectively.</p>c, d, e<p>A significant difference with control group, low dose group and medium dose group, respectively.</p>f, g<p>A significant difference with test substance and diet, respectively.</p

The fractional contribution of diet and test substance in different dose group in feces samples.

<p>The fractional contribution of diet and test substance in different dose group in feces samples.</p

Statistical significance of differences in ²⁰⁸Pb/²⁰⁶Pb for test substance, diet, blood, urine, and feces in different dose groups (n = 6) of respiratory lead exposure.

<p>Note: Difference are significant when <i>p</i><0.05 level.</p>a, b<p>A significant difference with blood and urine, respectively.</p>c, d, e<p>A significant difference with control group, low dose group and medium dose group, respectively.</p>f, g<p>A significant difference with test substance and diet, respectively.</p

Atg7 Knockdown Augments Concanavalin A-Induced Acute Hepatitis through an ROS-Mediated p38/MAPK Pathway

<div><p>Concanavalin A (ConA), a T-cell mitogen that induces acute autoimmune hepatitis, is widely used to model pathophysiological processes of human acute autoimmune liver disease. Although autophagy has been extensively studied in the past decade, little is known about its molecular mechanism underlying the regulation of ConA-induced acute hepatitis. In this study, we used a Cre-conditional <i>atg7</i> KO mouse to investigate the effects of Atg7-associated autophagy on ConA-induced murine hepatitis. Our results demonstrated that <i>atg7</i> deficiency in mice enhanced macrophage activation and increased pro-inflammatory cytokines upon ConA stimulation. Atg7 silencing resulted in accumulation of dysfunctional mitochondria, disruption of reactive oxygen species (ROS) degradation, and increase in pro-inflammatory cytokines in Raw264.7 cells. p38/MAPK and NF-κB levels were increased upon ConA induction due to Atg7 deficiency. Blocking ROS production inhibited ConA-induced p38/IκB phosphorylation and subsequent intracellular inflammatory responses. Hence, this study demonstrated that <i>atg7</i> knockout in mice or Atg7 knockdown in cell culture augmented ConA-induced acute hepatitis and related cellular malfunction, indicating protective effects of Atg7 on regulating mitochondrial ROS via a p38/MAPK-mediated pathway. Collectively, our findings reveal that autophagy may attenuate macrophage-mediated inflammatory response to ConA and may be the potential therapeutic targets for acute liver injury.</p></div

Putative mechanism in which Atg7 knockdown augments ConA-induced hepatic injury through an ROS-mediated p38/MAPK pathway in intra-hepatic macrophages.

<p>Putative mechanism in which Atg7 knockdown augments ConA-induced hepatic injury through an ROS-mediated p38/MAPK pathway in intra-hepatic macrophages.</p

Atg7 silencing resulted in accumulation of dysfunctional mitochondria and abolished ROS degradation in Raw264.7 cells.

<p><b>A.</b> Cell viability measured by an MTT assay and ROS production by mean fluorescence intensity of H₂DCF-DA at different concentrations and time points for ConA exposure in Raw264.7 cells lacking Atg7. <b>B.</b> Measurement of mitochondria membrane potential and SOD activity after ConA stimulation. Raw264.7 cells were transfected with Atg7 siRNA or control siRNA and treated with 10 μg/ml ConA for 24 h. Representative results were from 3 independent experiments. Data are presented as mean±SD; * <i>p</i><0.05 and ** <i>p</i><0.01 vs. controls, # <i>p</i><0.05 and ## <i>p</i><0.01 vs. pre-treatments. <b>C and D.</b> Fluorescence microscopy of mitochondrial membrane by Mito-tracker Red FM (red) and ROS production by H₂DCF-DA (green) after ConA stimulation (Arrows showing fluorescence staining regions). Raw264.7 cells were transfected with Atg7 siRNA or control siRNA and treated with 10 μg/ml ConA for 4 h. Magnifications: 1000X. Representative results were from 3 independent experiments.</p