Ozone is a highly toxic air pollutant and global health concern. Mechanisms of genetic susceptibility to ozone-induced lung inflammation are not completely understood. We hypothesized Notch3 and Notch4 are important determinants of susceptibility to ozone-induced lung inflammation. Wild type (WT), Notch3 (Notch3-/-) and Notch4 (Notch4-/-) knockout mice were exposed to ozone (0.3 ppm) or filtered air for 6-72 hours. Ozone increased bronchoalveolar lavage fluid (BALF) protein, a marker of lung permeability, in all genotypes, but significantly greater concentrations were found in Notch4-/- compared to WT and Notch3-/-. Significantly greater mean numbers of BALF neutrophils were found in Notch3-/- and Notch4-/- mice compared to WT mice after ozone. Expression of whole lung Tnf was significantly increased after ozone in all genotypes, and was significantly greater in Notch3-/- mice compared to WT. Statistical analyses of the transcriptome identified differentially expressed gene networks between WT and knockout mice basally and after ozone, and included Trim30, a member of the inflammasome pathway, and Traf6, an inflammatory signaling member. These novel findings are consistent with Notch3 and Notch4 as susceptibility genes for ozone-induced lung injury, and suggest that Notch receptors protect against innate immune inflammation.
Novel Roles for Notch3 and Notch4 Receptors in Gene Expression and Susceptibility to Ozone-Induced Lung Inflammation in Mice.
Specimen part
View SamplesCell type specific transcriptome analysis from laser microdissected megaspore mother cells (MMC) from Arabidopsis thaliana (L.) Heynh., accession Landsberg erecta.
Transcriptome analysis of the Arabidopsis megaspore mother cell uncovers the importance of RNA helicases for plant germline development.
Sex, Specimen part, Subject
View SamplesNucellus tissue surrounding the megaspore mother cell in Arabidopsis thaliana (L.) Heynh. , accession Landsberg erecta, isolated by laser assisted microdissection
Transcriptome analysis of the Arabidopsis megaspore mother cell uncovers the importance of RNA helicases for plant germline development.
Specimen part, Subject
View SamplesThe goal of this study was to examine whether immune responses to Plasmodium chabaudi infection differ between the sexes and are altered by the presence of gonadal steroids. Gonadally-intact males were more likely than intact females to die following P. chabaudi infection, exhibit slower recovery from infection-associated weight loss, hypothermia, and anemia, have reduced IFN-associated gene expression and IFN production during peak parasitemia, and produce less antibody during the recovery phase of infection. Gonadectomy of male and female mice altered these sex-associated differences, suggesting that sex steroid hormone, in particular androgens and estrogens, may modulate immune responses to infection.
Involvement of gonadal steroids and gamma interferon in sex differences in response to blood-stage malaria infection.
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View SamplesWe previously identified toll-like receptor 4 (Tlr4) as a candidate gene responsible for ozone (O3)-induced pulmonary hyperpermeability and inflammation. The objective of this study was to determine the mechanism through which TLR4 modulates O3-induced pulmonary responses and to utilize transcriptomics to determine TLR4 effector molecules. C3H/HeJ (HeJ; Tlr4 mutant) and C3H/HeOuJ (OuJ; Tlr4 normal), mice were exposed continuously to 0.3 ppm O3 or filtered air for 6, 24, 48 or 72 hr. Affymetrix Mouse430A_MOE gene arrays were used to analyze lung homogenates from HeJ and OuJ mice followed using a bioinformatic analysis. Inflammation was assessed by bronchoalveolar lavage and molecular analysis by ELISA, immunoblotting, and transcription factor activity. TLR4 signals through both the MYD88-dependent and independent pathways in OuJ mice, which involves MAP kinase activation, NF-kappaB, AP-1, and KC. Microarray analyses identifiedTLR4 responsive genes for strain and time in OuJ versus HeJ mice (p<0.05). One significantly upregulated cluster of genes in OuJ were the heat shock proteins (Hspa1b; Hsp70), Hsp90ab1). Furthermore, O3-induced expression of HSP70 protein was increased in OuJ compared to HeJ mice following 24-48 h O3. Moreover, BAL polymorphonuclear leukocytes (PMN) and total protein were significantly reduced in response to O3 in Hspa1a/Hspa1btm1Dix (Hsp70-/-) compared to Hsp70+/+ mice (p<0.05). TLR4 signaling (MYD88-dependent), ERK1/2, AP-1 activity, and KC protein content were also significantly reduced after O3 exposure in Hsp70-/- compared to Hsp70+/+ mice (p<0.05). These studies suggest that HSP70 is involved in the regulation of O3-induced lung inflammation through the TLR4 pathway and provide evidence that HSP70 is an endogenous in vivo TLR4 ligand.
Identification of candidate genes downstream of TLR4 signaling after ozone exposure in mice: a role for heat-shock protein 70.
Sex, Specimen part, Treatment
View SamplesWe hypothesize that gene expression in the Type II cells of Nrf2+/+ and Nrf2-/- mice are divergent thus contributing the cell growth. More specifically, type II cells from Nrf2-/- mice have increased reactive oxygen species that cause the impaired cell growth. In order to test these hypotheses at the gene expression level, we utilized microarray analysis to examine transcriptional differences between Nrf2+/+ and Nrf2-/- cells.
Genetic dissection of the Nrf2-dependent redox signaling-regulated transcriptional programs of cell proliferation and cytoprotection.
No sample metadata fields
View SamplesConsumption of diets rich in fibers has been associated with several beneficial effects on gastrointestinal health. However, detailed studies on the molecular effects of fibers in colon are limited. In this study we investigated and compared the influence of five different fibers on the mucosal transcriptome, and luminal microbiota and SCFA concentrations in murine colon. Mice were fed diets enriched with fibers that differed in carbohydrate composition, namely inulin (IN), oligofructose (FOS), arabinoxylan (AX), guar gum (GG), resistant starch (RS) or a control diet (corn starch) for 10 days. Gene expression profiling revealed the regulation of specific, but also overlapping sets of epithelial genes by each fiber, which on a functional level were mainly linked to cell cycle and various metabolic pathways including fatty acid oxidation, tricarboxylic acid cycle, and electron transport chain. In addition, the transcription factor PPAR was predicted to be a prominent upstream regulator of these processes. Microbiota profiles were distinct per dietary fiber, but the fibers IN, FOS, AX and GG induced a common change in microbial groups. All dietary fibers, except resistant starch, increased SCFA concentrations but to a different extent. Multivariate data integration revealed strong correlations between the expression of genes involved in energy metabolism and the relative abundance of bacteria belonging to the group of Clostridium cluster XIVa, that are known butyrate producers. These findings illustrate the potential of multivariate data analysis to unravel simple relationships in complex systems.
Comparison of the effects of five dietary fibers on mucosal transcriptional profiles, and luminal microbiota composition and SCFA concentrations in murine colon.
Sex, Age, Specimen part
View SamplesToll like receptor 4 (TLR4), an innate immunity gene, is involved in responses to several pulmonary agonists including endotoxin (LPS; Poltorak et al.,1998), ozone (O3 ,Kleeberger et. al., 2001), Pseudomonas aeruginosa (Faure et al, 2004), and hyperoxia (Zhang et al, 2005). TLR4 appears to partially mediate the response to LPS- and O3-induced lung injury, however, TLR4 is protective for prevention of injury in Pseudomonas aeruginosa infection and against acute lung injury (hyperoxia). The mechanism behind this protection is unclear. We previously demonstrated that TLR4 was also protective against BHT-induced chronic inflammation and tumor promotion (Bauer et al, 2005). C.C3H-Tlr4Lps-d (BALBLps-d) mice, congenic for a 10 cM region of C3H/HeJ chromosome 4 that contains Tlr4 (Vogel et al, 1994), have a missence mutation that renders TLR4 dysfunctional. The Tlr4 mutation likely abrogates signaling by disrupting a direct point of contact with other signaling molecules (Akira S, Takeda K. Toll-like receptor signalling. Nat Rev Immunol 2004;4(7):499-511.). Bronchoalveolar lavage fluid (BALF) alveolar macrophages, lymphocytes, and total protein content were significantly elevated in BALBLps-d mice compared to BALB/c (BALB; Tlr4 sufficient) mice following chronic BHT (Bauer et al., 2005). BALBLps-d mice also had a significant increase in tumor multiplicity (60%) over that of BALB mice in response to an MCA/BHT tumor promotion protocol. While this was the first model to demonstrate a protective role for TLR4 in chronic lung inflammation and tumorigenesis, the downstream mechanism regulating this protective response remains unknown. Using Affymetrix microarray analysis followed by GeneSpring and Ingenuity pathway analyses, we herein identified known and novel downstream pathways and their interactions that may be involved in the protective mechanism elicited by TLR4. We therefore hypothesize that these pathways and interactions amongst the genes identified during the tumor promotion/chronic inflammation stage are in part influencing the differential strain response observed during tumorigenesis.
Transcriptomic analysis of pathways regulated by toll-like receptor 4 in a murine model of chronic pulmonary inflammation and carcinogenesis.
No sample metadata fields
View SamplesBackground: The mechanisms underlying ozone (O3)-induced pulmonary inflammation remain unclear. Interleukin (IL)-10 is an anti-inflammatory cytokine that is known to inhibit inflammatory mediators.
Protective role of interleukin-10 in ozone-induced pulmonary inflammation.
Sex, Specimen part
View SamplesPrior microarray studies of smokers at high risk for lung cancer have demonstrated that heterogeneity in bronchial airway epithelial cell gene expression response to smoking can serve as an early diagnostic biomarker for lung cancer. This study examines the relationship between gene expression variation and genetic variation in a central molecular pathway (NRF2-mediated antioxidant response) associated with smoking exposure and lung cancer. We assessed global gene expression in histologically normal airway epithelial cells obtained at bronchoscopy from smokers who developed lung cancer (SC, n=20), smokers without lung cancer (SNC, n=24), and never smokers (NS, n=8). Functional enrichment showed that the NRF2-mediated antioxidant response pathway differed significantly among these groups.
Genetic variation and antioxidant response gene expression in the bronchial airway epithelium of smokers at risk for lung cancer.
Sex, Age, Specimen part, Race, Subject
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