Leukemia inhibitory factor (LIF) is amongst the IL-6 family cytokines expressed in the lungs during pneumonia. However, the function of endogenous LIF during pneumonia has never been explored. The purpose of this study was to determine the transcriptional response to pneumonia in the lungs and whether or how this response is influenced by LIF.
Leukemia inhibitory factor signaling is required for lung protection during pneumonia.
Specimen part
View SamplesAlveolar macrophages orchestrate pulmonary innate immunity and are essential for early immune surveillance and clearance of microorganisms in the airways. Inflammatory signaling must be sufficiently robust to promote host defense but limited enough to prevent excessive tissue injury. Macrophages in the lungs utilize multiple transcriptional and post-transcriptional mechanisms of inflammatory gene expression to delicately balance the elaboration of immune mediators. RNA terminal uridyltransferases (TUTs), including the closely homologous family members Zcchc6 (TUT7) and Zcchc11 (TUT4), have been implicated in the post-transcriptional regulation of inflammation from studies conducted in vitro. In vivo, we observed that Zcchc6 is expressed in mouse and human primary macrophages. Zcchc6-deficient mice are viable and born in Mendelian ratios and do not exhibit an observable spontaneous phenotype under basal conditions. Following an intratracheal challenge with S. pneumoniae, Zcchc6 deficiency led to a modest but significant increase in the expression of select cytokines including IL-6, CXCL1, and CXCL5. These findings were recapitulated in vitro whereby Zcchc6-deficient macrophages exhibited similar increases in cytokine expression due to bacterial stimulation. Although loss of Zcchc6 also led to increased neutrophil emigration to the airways during pneumonia, these responses were not sufficient to impact host defense against infection.
The RNA uridyltransferase Zcchc6 is expressed in macrophages and impacts innate immune responses.
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View SamplesA growing body of evidence suggests that epithelial cells have special roles during pneumonia. The purpose of this study was to elucidate epithelial-specific responses during lung infection.
Epithelial Cell-Derived Secreted and Transmembrane 1a Signals to Activated Neutrophils during Pneumococcal Pneumonia.
Specimen part
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Hepatocyte-specific mutation of both NF-κB RelA and STAT3 abrogates the acute phase response in mice.
Specimen part
View SamplesA common response to physiological duress is the hepatic acute phase response, a process during which the expression of many genes is altered in the liver. Amongst these transcripts are those encoding acute phase proteins, defined as circulating proteins with significantly changed concentrations during an acute phase response. The goal of this study was to determine the influence of two transcription factors, STAT3 and NF-kappaB p65 (RelA), on hepatic gene changes including but not limited to acute phase proteins during bacterial pneumonia.
Hepatocyte-specific mutation of both NF-κB RelA and STAT3 abrogates the acute phase response in mice.
Specimen part
View SamplesA common response to physiological duress is the hepatic acute phase response, a process during which the expression of many genes is altered in the liver. Amongst these transcripts are those encoding acute phase proteins, defined as circulating proteins with significantly changed concentrations during an acute phase response. The goal of this study was to determine the influence of NF-kappaB RelA (p65) on hepatic gene changes including but not limited to acute phase proteins during bacterial pneumonia.
Hepatocyte-specific mutation of both NF-κB RelA and STAT3 abrogates the acute phase response in mice.
Specimen part
View SamplesA common response to physiological duress is the hepatic acute phase response, a process during which the expression of many genes is altered in the liver. Amongst these transcripts are those encoding acute phase proteins, defined as circulating proteins with significantly changed concentrations during an acute phase response. The goal of this study was to determine the influence of STAT3 on hepatic gene changes including but not limited to acute phase proteins during bacterial pneumonia.
Hepatocyte-specific mutation of both NF-κB RelA and STAT3 abrogates the acute phase response in mice.
Specimen part
View SamplesCre-recombinase expression under control of an albumin promoter in the presence of floxed alleles is a highly effective and specific way to target gene mutations in hepatocytes. However, some concerns have been raised regarding off-target and/or toxic effects of cre itself, possibly confounding the interpretation of studies employing this approach. We have now used this tool to succesfully target gene deletions in hepatocytes during pneumonia, a condition which results in significant remodeling of the hepatic transcriptome. The goal of this study was to determine what effects, if any, cre expression alone has on hepatic gene expression during bacterial pneumonia.
Hepatocyte-specific mutation of both NF-κB RelA and STAT3 abrogates the acute phase response in mice.
Specimen part
View SamplesCommunity-acquired pneumonia is a widespread disease with significant morbidity and mortality. Alveolar macrophages are tissue-resident lung cells that play a crucial role in innate immunity against bacteria causing pneumonia. We hypothesized that alveolar macrophages display adaptive characteristics after resolution of bacterial pneumonia. We studied mice one to six months after self-limiting lung infection due to Streptococcus pneumoniae, the most common cause of bacterial pneumonia. Among the myeloid cells recovered from the lung, only alveolar macrophages showed long-term modifications of their surface marker phenotype. The remodeling of alveolar macrophages was: (i) long-lasting (still observed 6 months post infection), (ii) regionally localized (only observed in the affected lobe after lobar pneumonia), and (iii) associated with a macrophage-dependent enhanced lung protection to another pneumococcal serotype. Metabolomic and transcriptomic profiling revealed that alveolar macrophages of mice which recovered from pneumonia had new baseline activities and altered responses to infection. Thus, the enhanced lung protection after mild and self-limiting respiratory infection includes a profound remodeling of alveolar macrophages that is long-lasting, compartmentalized, and manifest across surface receptors, metabolites, and both resting and stimulated transcriptomes.
Pneumonia recovery reprograms the alveolar macrophage pool.
Specimen part, Treatment
View SamplesLoss of Notch1 in retinal progenitor cells (RPCs) during postnatal retinal development results in the overproduction of rod photoreceptors at the expense of interneurons and glia. To examine the molecular underpinnings of this observation, microarray analysis of singla retinal cells from wildtype (WT) or Notch1 conditional knockout (N1-CKO) retinas was performed. The majority of N1-CKO cells lost expression of known Notch target genes. These cells also had low levels of RPC and cell cycle genes, and robustly upregulated rod precursor genes. In addition, single WT cells, in which cell cycle marker genes were downregulated, expressed markers of both rod photoreceptors and interneurons. These results demonstrate that individual, newly postmitotic retinal cells can begin to differentiate into more than one cell type, and that this transitional state may be dependent on Notch1 signaling.
Notch1 is required in newly postmitotic cells to inhibit the rod photoreceptor fate.
Specimen part
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