Cystic fibrosis (CF) is a life-shortening disease caused by mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) gene. Although bacterial lung infection and the resulting inflammation cause most of the morbidity and mortality, how loss of CFTR first disrupts airway host defense has remained uncertain. We asked what abnormality impairs elimination when a bacterium lands on the pristine surface of a newborn CF airway? To investigate this defect, we interrogated the viability of individual bacteria immobilized on solid grids and placed on the airway surface. As a model we studied CF pigs, which spontaneously develop hallmark features of CF lung disease. At birth, their lungs lack infection and inflammation, but have a reduced ability to eradicate bacteria. Here we show that in newborn wild-type pigs, the thin layer of airway surface liquid (ASL) rapidly killed bacteria in vivo, when removed from the lung, and in primary epithelial cultures. Lack of CFTR reduced bacterial killing. We found that ASL pH was more acidic in CF, and reducing pH inhibited the antimicrobial activity of ASL. Reducing ASL pH diminished bacterial killing in wild-type pigs, and increasing ASL pH rescued killing in CF pigs. These results directly link the initial host defense defect to loss of CFTR, an anion channel that facilitates HCO3- transport. Without CFTR, airway epithelial HCO3- secretion is defective, ASL pH falls and inhibits antimicrobial function, and thereby impairs killing of bacteria that enter the newborn lung. These findings suggest that increasing ASL pH might prevent the initial infection in patients with CF and that assaying ASL pH or bacterial killing could report on the benefit of therapeutic interventions.
Reduced airway surface pH impairs bacterial killing in the porcine cystic fibrosis lung.
Specimen part
View SamplesLung disease causes most of the morbidity and mortality in cystic fibrosis (CF). However, understanding its pathogenesis has been hindered by lack of an animal model with characteristic features of CF. To overcome this problem, we recently generated pigs with targeted CFTR genes. We now report that within months of birth, CF pigs spontaneously develop hallmark features of CF lung disease including airway inflammation, remodeling, mucus accumulation, and infection. Their lungs contained multiple bacterial species, suggesting an equal opportunity host defense defect. In humans, the temporal and/or causal relationships between inflammation and infection have remained uncertain. To investigate these processes, we studied newborn pigs. Their lungs showed no inflammation, but were less often sterile than controls. Moreover, after intrapulmonary bacterial challenge, CF pigs failed to eradicate bacteria as effectively as wild- type pigs. These results suggest that impaired bacterial elimination is the pathogenic event that initiates a cascade of inflammation and pathology in CF lungs. Finding that CF pigs have a bacterial host defense defect within hours of birth provides an exciting opportunity to further investigate pathogenesis and to test therapeutic and preventive strategies before secondary consequences develop.
Cystic fibrosis pigs develop lung disease and exhibit defective bacterial eradication at birth.
Specimen part
View SamplesDrosophila melanogaster expresses three classes of small RNAs, which are classified according to their mechanisms of biogenesis. MicroRNAs are ~22-23-nt, ubiquitously expressed small RNAs that are sequentially processed from hairpin-like precursors by Drosha/Pasha and Dcr-1/Loquacious complexes. MicroRNAs usually associate with AGO1 and regulate the expression of protein-coding genes. Piwi-interacting RNAs (piRNAs) of ~24-28-nt associate with Piwi-family proteins and can arise from single-stranded precursors. piRNAs function in transposon silencing and are mainly restricted to gonadal tissues. Endo-siRNAs are found in both germline and somatic tissues. These ~21-nt RNAs are produced by a distinct Dicer, Dcr-2, and do not depend on Drosha/Pasha complexes. They predominantly bind to AGO2 and target both mobile elements and protein-coding genes. Surprisingly, a subset of endo-siRNAs strongly depend for their production on the dsRNA-binding protein Loquacious (Loqs), thought generally to be a partner for Dcr-1 and a co-factor for miRNA biogenesis. Endo-siRNA production depends on a specific Loqs isoform, Loqs-PD, which is distinct from the one, Loqs-PB, required for the production of microRNAs. Paralleling their roles in the biogenesis of distinct small RNA classes, Loqs-PD and Loqs-PB bind to different Dicer proteins, with Dcr-1/Loqs-PB complexes and Dcr-2/Loqs-PD complexes driving microRNA and endo-siRNA biogenesis, respectively. Small RNA profiling by high throughput sequencing Overall design: Total RNA was isolated using Trizol reagent (Invitrogen) and size-fractionated by PAGE into 19-24nt. These were independently processed and sequenced using the Illumina GAII platform. In total, six libraries were analyzed.
Processing of Drosophila endo-siRNAs depends on a specific Loquacious isoform.
Cell line, Subject
View SamplesThis SuperSeries is composed of the SubSeries listed below.
GATA4 and LMO3 balance angiocrine signaling and autocrine inflammatory activation by BMP2 in liver sinusoidal endothelial cells.
Specimen part, Treatment
View SamplesLiver sinusoidal endothelial cells (LSEC) represent a unique, organ-specific type of discontinuous endothelial cells. LSEC instruct the hepatic vascular niche by paracrine-acting angiocrine factors. Recently, we have shown that LSEC-specific transcriptional regulator GATA4 induces expression of BMP2 in cultured endothelial cells (EC) in vitro. Furthermore, angiocrine Bmp2 signaling in the liver in vivo was demonstrated to control iron homeostasis. Here, we investigated GATA4-dependent autocrine BMP2 signaling in endothelial cells by gene expression profiling. GATA4 induced a large cluster of inflammatory endothelial response genes in cultured EC, which is similar to previously identified virus-induced and interferon-associated responses. Treating the cells with the BMP2 inhibitor Noggin counter-regulated the GATA4-dependent inflammatory phenotype of EC, indicating that BMP2 is indeed the major driver. In contrast to continuous EC, LSEC were less prone to activation by BMP2. Notably, GATA4-dependent induction of the inflammatory EC response gene cluster was attenuated by over-expression of the LSEC-specific transcriptional modifier LMO3 while hepatocyte activation was fully preserved, indicating conserved BMP2 synthesis. In summary, our data suggest that transcriptional counter-regulation by GATA4 and LMO3 in LSEC prevents autocrine induction of an inflammatory phenotype, while maintaining angiocrine BMP2-mediated cell communication in the liver vascular niche.
GATA4 and LMO3 balance angiocrine signaling and autocrine inflammatory activation by BMP2 in liver sinusoidal endothelial cells.
Specimen part, Treatment
View SamplesLiver sinusoidal endothelial cells (LSEC) represent a unique, organ-specific type of discontinuous endothelial cells. LSEC instruct the hepatic vascular niche by paracrine-acting angiocrine factors. Recently, we have shown that LSEC-specific transcriptional regulator GATA4 induces expression of BMP2 in cultured endothelial cells (EC) in vitro. Furthermore, angiocrine Bmp2 signaling in the liver in vivo was demonstrated to control iron homeostasis. Here, we investigated GATA4-dependent autocrine BMP2 signaling in endothelial cells by gene expression profiling. GATA4 induced a large cluster of inflammatory endothelial response genes in cultured EC, which is similar to previously identified virus-induced and interferon-associated responses. Treating the cells with the BMP2 inhibitor Noggin counter-regulated the GATA4-dependent inflammatory phenotype of EC, indicating that BMP2 is indeed the major driver. In contrast to continuous EC, LSEC were less prone to activation by BMP2. Notably, GATA4-dependent induction of the inflammatory EC response gene cluster was attenuated by over-expression of the LSEC-specific transcriptional modifier LMO3 while hepatocyte activation was fully preserved, indicating conserved BMP2 synthesis. In summary, our data suggest that transcriptional counter-regulation by GATA4 and LMO3 in LSEC prevents autocrine induction of an inflammatory phenotype, while maintaining angiocrine BMP2-mediated cell communication in the liver vascular niche.
GATA4 and LMO3 balance angiocrine signaling and autocrine inflammatory activation by BMP2 in liver sinusoidal endothelial cells.
Specimen part, Treatment
View SamplesThis SuperSeries is composed of the SubSeries listed below.
The alarmin IL-33 promotes regulatory T-cell function in the intestine.
Specimen part
View SamplesIL-23 negatively regulates St2 and Gata3 expression in intestinal CD4+ T cells
The alarmin IL-33 promotes regulatory T-cell function in the intestine.
Specimen part
View SamplesHyperglycemic memory is part of the pathogenesis of diabetic retinopathy. We established a novel mouse model of intermediate-term hyperglycemic memory and demonstrated that changes in gene expression and microvascular damage in the neurovascular unit of the diabetic retina persist after euglycemic reentry, indicating memory.
Hyperglycaemic memory affects the neurovascular unit of the retina in a diabetic mouse model.
Specimen part, Disease
View SamplesThe signaling pathways orchestrating both the evolution and development of language in the human brain remain unknown. To date, the transcription factor FOXP2 is the only gene implicated in Mendelian forms of human speech and language dysfunction1,2. It has been proposed, that the amino acid composition in the human variant of FOXP2 has undergone accelerated evolution, and this change occurred around the time of language emergence in humans3,4. However, this remains controversial, and whether the acquisition of these amino acids in human FOXP2 has any functional consequence in human neurons remains untested. Here, we demonstrate that these two amino acids confer new functionality in terms of differential transcriptional regulation, and extend these observations to in vivo brain, showing that several of the differential FOXP2 targets significantly overlap with genes different between human and chimpanzee brain. We also identify novel relationships among the differentially expressed genes with additional critical regulators of neuronal development. These data provide support for the functional relevance of changes that occur on the human lineage by showing that the two amino acids unique to human FOXP2 can lead to significant differences in gene expression patterns across brain evolution, with direct consequences for human brain development and disease. Since FOXP2 has an important role in the use of language in humans, the identified targets may have a critical function in the development and evolution of language circuitry in humans.
Human-specific transcriptional regulation of CNS development genes by FOXP2.
Specimen part, Cell line
View Samples