Introduction: Renal ischemia-reperfusion (IR) causes acute kidney injury (AKI) with high mortality and morbidity. The objective of this study was to ameliorate kidney IR injury and identify novel biomarkers for kidney injury and repair. Methods: Left renal ischemia was induced in rats by clamping renal artery for 45 minutes, followed by reperfusion and right nephrectomy. Thirty minutes prior to ischemia, rats (n=8/group) received Valproic Acid (150 mg/kg; VPA), Dexamethasone (3 mg/kg; Dex) or Vehicle (Saline) intraperitoneally. Animals were sacrificed at 3h, 24h or 120h post- IR and blood, urine and kidney were collected. Results: Serum creatinine (mg/dL) at 24 h IR in VPA (2.71.8) and Dex (2.31.2) was reduced (P<0.05) compared to Vehicle (3.80.5). At 3h post-IR, urine albumin (mg/ml) was higher in Vehicle (1.470.10), VPA (0.840.62) and Dex (1.040.73) compared to uninjured/untreated control (0.140.26) group. At 24h post-IR urine Lipocalin-2 (g/ml) was significantly higher (P<0.05) in VPA, Dex and Vehicle groups (9.61-11.36) compared to uninjured/untreated control (0.67o.29); also, Kidney Injury Molecule-1 (KIM-1; ng/ml) was significantly higher in VPA, Dex and Vehicle groups (13.7-18.7) compared uninjured/untreated control (1.71.9). KIM-1 levels were significantly (P<0.05) higher in all groups compared to uninjured/untreated control levels. Histopathology at 3h post IR demonstrated (P<0.05) reduction in ischemic injury in the renal cortex in VPA (Grade 1.6 1.5) compared to Vehicle (Grade 2.91.1) group. Inflammatory cytokines IL1 and IL6 were down-regulated in VPA and Dex groups. BCL2 was higher in VPA group. DNA microarray analysis demonstrated reduced stress response and injury, and improved recovery related gene expression in the kidneys of VPA treated animals. Conclusions: VPA administration reduced kidney IR injury and improved regeneration. KIM-1 and Lipocalin-2 appear to be promising early urine biomarkers of acute ischemic kidney injury.
Effects of valproic acid and dexamethasone administration on early bio-markers and gene expression profile in acute kidney ischemia-reperfusion injury in the rat.
Sex, Specimen part, Treatment
View SamplesCobalt is a transition group metal present in trace amounts in the human diet, but in larger doses it can be acutely toxic or cause adverse health effects in chronic, long term exposures. Its use in many industrial processes and alloys worldwide presents opportunities for occupational exposures, as well as exposures to military personnel. While the toxic effects of cobalt have been widely studied, the exact mechanisms of toxicity remain unclear. In order to further elucidate these mechanisms and identify potential biomarkers of exposure or effect, we exposed two rat liver-derived cell lines, H4-II-E-C3 and MH1C1, to two concentrations of cobalt chloride. We examined changes in gene expression using DNA microarrays in both cell lines and examined changes in cytoplasmic protein abundance in MH1C1 cells using mass spectrometry. We chose to closely examine differentially expressed genes and proteins changing in abundance in both cells lines in order to remove cell line specific effects. We identified enriched pathways, networks, and biological functions using commercial bioinformatic tools and manual annotation. Many of the genes, proteins, and pathways modulated by exposure to cobalt appear to be due to an induction of a hypoxic-like response and oxidative stress. Genes that may be differentially expressed due to a hypoxic-like response are involved in Hif-1 signaling, glycolysis, gluconeogenesis, and other energy metabolism related processes. Gene expression changes linked to oxidative stress are also known to be involved in the NRF2-mediated response, protein degradation, and glutathione production. Using microarray and mass spectrometry analysis, we were able to identify modulated genes and proteins, further elucidate the mechanisms of toxicity of cobalt, and identify biomarkers of exposure and effect in vitro, providing targets for focused in vitro studies.
Exposure to cobalt causes transcriptomic and proteomic changes in two rat liver derived cell lines.
Cell line
View SamplesU.S. Service Members and civilians are at risk of exposure to a variety of environmental health hazards throughout their normal duty activities and in industrial occupations. Metals are widely used in large quantities in a number of industrial processes and are a common environmental toxicant, which increases the possibility of being exposed at toxic levels. While metal toxicity has been widely studied, the exact mechanisms of toxicity remain unclear. In order to further elucidate these mechanisms and identify candidate biomarkers, rats were exposed via a single intraperitoneal injection to three concentrations of CdCl2 and Na2Cr2O7, with livers harvested at 1, 3, or 7 days after exposure. Cd and Cr accumulated in the liver at 1 day post exposure. Cd levels remained elevated over the length of the experiment, while Cr levels declined. Metal exposures induced ROS, including hydroxyl radical (OH), resulting in DNA strand breaks and lipid peroxidation. Interestingly, ROS and cellular damage appeared to increase with time post-exposure in both metals, despite declines in Cr levels. Differentially expressed genes were identified via microarray analysis. Both metals perturbed gene expression in pathways related to oxidative stress, metabolism, DNA damage, cell cycle, and inflammatory response. This work provides insight into the temporal effects and mechanistic pathways involved in acute metal intoxication, leading to the identification of candidate biomarkers.
Temporal changes in rat liver gene expression after acute cadmium and chromium exposure.
Specimen part, Treatment
View SamplesBackground: The in vivo gene response associated with hyperthermia and subsequent return to homeostasis or development of heat illness is poorly understood. Early activation of gene networks in the heat stress response is likely to lead to the systemic inflammation, multi-organ functional impairment, and other pathophysiological states characteristic of heat illness. Here, we perform an unbiased global characterization of the multi-organ gene response using an in vivo model of heat stress in the conscious rat.
Patterns of gene expression associated with recovery and injury in heat-stressed rats.
Sex, Specimen part
View SamplesPredicting liver injury after exposure to toxic industrial chemicals is complicated by the large number of potential environmental contaminants, mixtures, and exposure dose and route scenarios. Identifying indicators of end organ injury can complement exposure-based assays and improve predictive power. A multiplexed approach was used to experimentally evaluate a panel of 67 genes predicted to be fibrogenic by computationally mining DrugMatrix, a publicly available repository of gene microarray data. Five-day oral gavage studies in male Sprague-Dawley rats dosed with varying concentrations of three fibrogenic compounds (allyl alcohol, carbon tetrachloride, and 4,4-methylenedianiline) and two non-fibrogenic compounds (bromobenzene and dexamethasone) were conducted. Fibrosis was definitively diagnosed by histopathology. Transcriptomics data matched the predictions made using the DrugMatrix data with greater than 90% accuracy. Microarray data were verified using a 67-plex panel Bioplex assay, confirming that the 67-plex panel constituted a biomolecular signature of hepatic fibrosis (Figure). Necrosis and inflammatory infiltration were comorbid with fibrosis. Interaction analysis identified 24 genes specific for the fibrosis phenotype. The protein product of the gene most strongly correlated with the fibrosis phenotype (Pcolce) was dose-dependently elevated in plasma from animals administered fibrogenic chemicals (p<0.05). PCOLCE is a novel biomarker candidate of fibrotic injury. These results support the development of gene panels for liver injury and may suggest bridging biomarkers for molecular mediators linked to histopathology.
Gene Expression Patterns Associated With Histopathology in Toxic Liver Fibrosis.
Sex, Specimen part
View SamplesComparison of normal neuroblasts with malignant neuroblastomas (low- and high-stage)
Human fetal neuroblast and neuroblastoma transcriptome analysis confirms neuroblast origin and highlights neuroblastoma candidate genes.
Sex, Specimen part, Disease, Disease stage, Subject
View SamplesImmune-Responsive Gene 1 (Irg1) is a mitochondrial enzyme that produces itaconate under inflammatory conditions principally in cells of myeloid lineage. Cell culture studies suggest that itaconate regulates inflammation through inhibitory effects on cytokine and reactive oxygen species production. To evaluate the functions of Irg1 in vivo, we challenged wild-type (WT) and Irg1 KO mice with Mycobacterium tuberculosis (Mtb) and monitored disease progression. Irg1 KO but not WT mice succumbed rapidly to Mtb, and mortality was associated with increased infection, inflammation, and pathology. Infection of LysM-Cre Irg1 flox, MPR8-Cre Irg1 flox, and CD11c-Cre Irg1 flox conditional knockout mice along with neutrophil depletion experiments revealed a role for Irg1 in alveolar macrophages and LysM+ myeloid cells in preventing neutrophil-mediated immunopathology and disease. RNA-seq analyses suggest that Irg1 and its production of itaconate temper Mtb-induced inflammatory responses in myeloid cells at the transcriptional level. Thus, Irg1 modulates inflammation to curtail Mtb-induced lung disease. Overall design: Neutrophils were purified from bone marrow of naïve mice by negative selection using magnetic-activated cell sorting beads (Miltenyi). Neutrophil purity (>95%) was assessed by flow cytometry as the percentage of Ly6G+ CD11b+ cells. Neutrophils were cultured in RPMI-1640 supplemented with 1% non-essential amino acids at 37°C, 5% CO2. GFP-Mtb was grown to mid-log phase, washed with PBS, sonicated to disperse clumps, and resuspended in neutrophil culture media. GFP-Mtb then was opsonized prior to infection by mixing with an equal volume of normal mouse sera (Sigma) and incubation at room temperature for 30 min. Neutrophils were mock-infected or infected with opsonized GFP-Mtb at MOI 1 and incubated at 37°C, 5% CO2.
<i>Irg1</i> expression in myeloid cells prevents immunopathology during <i>M. tuberculosis</i> infection.
Specimen part, Cell line, Subject, Time
View SamplesImmune-Responsive Gene 1 (Irg1) is a mitochondrial enzyme that produces itaconate under inflammatory conditions principally in cells of myeloid lineage. Cell culture studies suggest that itaconate regulates inflammation through inhibitory effects on cytokine and reactive oxygen species production. To evaluate the functions of Irg1 in vivo, we challenged wild-type (WT) and Irg1-/- mice with Mycobacterium tuberculosis (Mtb) and monitored disease progression. Irg1-/- but not WT mice succumbed rapidly to Mtb, and mortality was associated with increased infection, inflammation, and pathology. Infection of LysM-Cre Irg1fl/fl, MPR8-Cre Irg1fl/fl, and CD11c-Cre Irg1fl/fl conditional knockout mice along with neutrophil depletion experiments revealed a role for Irg1 in alveolar macrophages and LysM+ myeloid cells in preventing neutrophil-mediated immunopathology and disease. RNA-seq analyses suggest that Irg1 and its production of itaconate temper Mtb-induced inflammatory responses in myeloid cells at the transcriptional level. Thus, Irg1 modulates inflammation to curtail Mtb-induced lung disease. Overall design: Macrophages were obtained by culturing bone marrow cells in RPMI-1640 (Invitrogen) supplemented with 10% heat inactivated fetal bovine serum, 2 mM L-glutamine, 1% non-essential amino acids, 100 U penicillin per mL, 100 µg streptomycin per mL, and 22 ng M-CSF (Peprotech) per ml for 6 days at 37°C, 5% CO2. Fresh media was added on day 3 of culture. After 6 days of culture, non-adherent cells were discarded. Adherent macrophages were switched into antibiotic-free media and seeded at 105 cells per well and 9 x 105 cells per well in tissue culture-treated 96 and 6 well plates respectively. In some cases, macrophages were treated with 0.25 mM itaconic acid (Sigma) for 12 h prior to inoculation with Mtb. Mtb was grown to mid-log phase, washed with PBS, sonicated to disperse clumps, and resuspended in antibiotic-free macrophage culture media. Macrophage cultures were inoculated by adding Mtb-containing media at a multiplicity of infection (MOI) of 1 and centrifuging for 10 min at 200 x g. Cells were washed twice with PBS to remove unbound Mtb, fresh culture media was added, and cells were incubated at 37°C, 5% CO2. In some cases culture media was supplemented with 0.25 mM itaconic acid.
<i>Irg1</i> expression in myeloid cells prevents immunopathology during <i>M. tuberculosis</i> infection.
Specimen part, Treatment, Subject
View SamplesImmune-Responsive Gene 1 (Irg1) is a mitochondrial enzyme that produces itaconate under inflammatory conditions principally in cells of myeloid lineage. Cell culture studies suggest that itaconate regulates inflammation through inhibitory effects on cytokine and reactive oxygen species production. To evaluate the functions of Irg1 in vivo, we challenged wild-type (WT) and Irg1 KO mice with Mycobacterium tuberculosis (Mtb) and monitored disease progression. Irg1 KO but not WT mice succumbed rapidly to Mtb, and mortality was associated with increased infection, inflammation, and pathology. Infection of LysM-Cre Irg1 flox, MPR8-Cre Irg1 flox, and CD11c-Cre Irg1 flox conditional knockout mice along with neutrophil depletion experiments revealed a role for Irg1 in alveolar macrophages and LysM+ myeloid cells in preventing neutrophil-mediated immunopathology and disease. RNA-seq analyses suggest that Irg1 and its production of itaconate temper Mtb-induced inflammatory responses in myeloid cells at the transcriptional level. Thus, Irg1 modulates inflammation to curtail Mtb-induced lung disease. Overall design: C57BL/6N (WT) mice were purchased from Charles River. B6.SJL (CD45.1) mice were obtained from Jackson Laboratories. Irg1-/- mice (embryonic stem cells obtained from KOMP (C57BL/6N background), MGI: 103206) were generated at Washington University. Adult mice (6-13 weeks of age) of both sexes were used, and sex was randomized between experiments. Neutrophils were purified by magnetic-activated cell sorting from the bone marrow of naïve mice (negative selection) or the lungs of Mtb-infected mice at 16 dpi (selection for Ly6G+ cells) (Miltenyi).
<i>Irg1</i> expression in myeloid cells prevents immunopathology during <i>M. tuberculosis</i> infection.
Specimen part, Cell line, Subject
View SamplesAim of the study was to characterize the transcriptional response of human primary renal proximal tubule epithelial cells (RPTEC) to low oxygen stress.
The histone demethylases JMJD1A and JMJD2B are transcriptional targets of hypoxia-inducible factor HIF.
Sex, Age, Specimen part, Disease, Disease stage
View Samples