The glomerular filtration barrier prevents large serum proteins from being lost into the urine. It is not known, however, why the filter does not routinely clog with large proteins that enter the glomerular basement membrane (GBM). Here we provide evidence that an active transport mechanism exists to remove immunoglobulins that accumulate at the filtration barrier. We found that FcRn, an IgG and albumin transport receptor, is expressed in podocytes and functions to internalize IgG from the GBM. Mice lacking FcRn accumulated IgG in the GBM as they aged and tracer studies showed delayed clearance of IgG from the kidneys of FcRn deficient mice. Supporting a role for this pathway in disease, saturating the clearance mechanism potentiated the pathogenicity of nephrotoxic sera. These studies support the idea that podocytes play an active role in removing proteins from the GBM and suggest that genetic or acquired impairment of the clearance machinery is likely to be a common mechanism promoting glomerular diseases.
Podocytes use FcRn to clear IgG from the glomerular basement membrane.
Specimen part
View SamplesComparison of gene expression profile of E. coli 83972 grown in minimal lab media, in urine and in 3 individual patients.
Global gene expression profiling of the asymptomatic bacteriuria Escherichia coli strain 83972 in the human urinary tract.
No sample metadata fields
View SamplesBackground and Aims: In the interleukin-10-deficient (Il10-/-) mouse model of IBD, 10 quantitative trait loci (QTL) have been shown to be associated with colitis susceptibility by linkage analyses on experimental crosses of highly susceptible C3H/HeJBir (C3Bir)-Il10-/- and partially resistant C57BL/6J (B6)-Il10-/- mice. The strongest locus (C3Bir-derived cytokine deficiency-induced colitis susceptibility [Cdcs]1 on Chromosome [Chr] 3) controlled multiple colitogenic subphenotypes and contributed the vast majority to the phenotypic variance in cecum and colon. This was demonstrated by interval-specific Chr 3 congenic mice wherein defined regions of Cdcs1 from C3Bir or B6 were bred into the IL-10-deficient reciprocal background and altered the susceptible or resistant phenotype. Furthermore, this locus likely acts by inducing innate hypo- and adaptive hyperresponsiveness, associated with impaired NFB responses of macrophages. The aim of the present study was to dissect the complexity of Cdcs1 by further development and characterization of reciprocal Cdcs1 congenic strains and to identify potential candidate genes in the congenic interval. Material and Methods: In total, 15 reciprocal congenic strains were generated from Il10-/- mice of either C3H/HeJBir or C57BL/6J backgrounds by 10 cycles of backcrossing. Colitis activity was monitored by histological grading. Candidate genes were identified by fine mapping of congenic intervals, sequencing, microarray analysis and a high-throughput real-time RT-PCR approach using bone marrow-derived macrophages. Results: Within the originally identified Cdcs1-interval, three independent regions were detected that likely contain susceptibility-determining genetic factors (Cdcs1.1, Cdcs1.2, and Cdcs1.3). Combining results of candidate gene approaches revealed Fcgr1, Cnn3, Larp7, and Alpk1 as highly attractive candidate genes with polymorphisms in coding or regulatory regions and expression differences between susceptible and resistant mouse strains. Conclusions: Subcongenic analysis of the major susceptibility locus Cdcs1 on mouse chromosome 3 revealed a complex genetic structure. Candidate gene approaches revealed attractive genes within the identified regions with homologs that are located in human susceptibility regions for IBD.
Cdcs1 a major colitis susceptibility locus in mice; subcongenic analysis reveals genetic complexity.
Sex, Specimen part
View SamplesThis SuperSeries is composed of the SubSeries listed below.
MicroRNA-203 represses selection and expansion of oncogenic Hras transformed tumor initiating cells.
Specimen part
View SamplesIdentification of genes differentially expressed in roots of Arabidopsis Col-0 and ndr1-1 mutants 48 h post inoculation with the fungal pathogen Verticillium longisporum.
Susceptibility to Verticillium longisporum is linked to monoterpene production by TPS23/27 in Arabidopsis.
Age, Specimen part, Time
View SamplesIn many mouse models of skin cancer, only a few tumors typically form although many cells competent for tumorigenesis receive the same oncogenic mutations. These observations suggest a selection process for defining tumor initiating cells. Here we use quantitative mRNA- and miR-Seq to determine the impact of HRasG12V on the transcriptome of keratinocytes. We discover that microRNA-203 is downregulated by HRasG12V. Using a knockout mouse model, we demonstrate that loss of microRNA-203 promotes selection and expansion of tumor-initiating cells. Conversely, restoration of microRNA-203 with an inducible model potently inhibits proliferation of these cells. We comprehensively identify microRNA-203 targets required for HRas-initiated tumorigenesis. These targets include important effectors of the Ras pathway and essential genes required for cell division. Together, this study establishes a role for the loss of microRNA-203 in promoting selection and expansion of HRas mutated cells and identifies a mechanism through which microRNA-203 antagonizes HRas-mediated tumorigenesis.
MicroRNA-203 represses selection and expansion of oncogenic Hras transformed tumor initiating cells.
Specimen part
View SamplesIn the absence of p63 expression, the epidermis fails to commit to stratification, resulting in aborted skin development. In this study, gene expression profiles of E18.5 p63 null and wt skin, were compared in an effort to identify genes that are directly or indirectly regulated by p63.
TAp63alpha induces AP-2gamma as an early event in epidermal morphogenesis.
No sample metadata fields
View SamplesThe development of the epidermis, a stratified squamous epithelium, is dependent on the regulated differentiation of keratinocytes. Differentiation begins with the initiation of stratification, a process tightly controlled through proper gene expression. AP-2 is expressed in skin and previous research suggested a pathway where p63 gene induction results in increased expression of AP-2 which in turn is responsible for induction of K14. This study uses a conditional gene ablation model to further explore the role of AP-2 in skin development. Mice deficient for AP-2 exhibited delayed expression of p63, K14, and K1, key genes required for development and differentiation of the epidermis. In addition, microarray analysis of E16.5 skin revealed delayed expression of additional late epidermal differentiation genes: filaggrin, repetin and secreted Ly6/Plaur domain containing 1, in mutant mice. The genetic delay in skin development was further confirmed by a functional delay in the formation of an epidermal barrier. These results document an important role for AP-2 in skin development, and reveal the existence of regulatory factors that can compensate for AP-2 in its absence.
Disruption of epidermal specific gene expression and delayed skin development in AP-2 gamma mutant mice.
No sample metadata fields
View SamplesThe loss of loricrin, a major component of the cornified envelope, results in a delay of epidermal barrier formation. Therefore, the living layers of the epidermis are aberrantly exposed to late-stage amniotic fluid, which may serve as the signal to upregulate genes that functionally compensate for the loss of loricrin. Consistent with this hypothesis, metabolomic studies revealed marked changes in amniotic fluid between E14.5 and E16.5 dpc. In addition, we discovered that the Nrf2/Keap1 pathway detects these compositional changes and directly upregulates the expression of genes involved in the compensatory response, thus ensuring postnatal survival. In support of this finding, we demonstrate that genetically blocking the Nrf2 pathway abolishes the compensatory response, and preemptively activating Nrf2 pharmacologically rescues the delay in barrier formation in utero. Our findings reveal that the functions of Nrf2 and the composition of amniotic fluid have co-evolved to ensure the formation of a functional barrier.
Amniotic fluid activates the nrf2/keap1 pathway to repair an epidermal barrier defect in utero.
Specimen part
View SamplesDetection of single feature polymorphisms comparing five barley genotypes. Gene expression under unstressed and drought stressed conditions.
Detecting single-feature polymorphisms using oligonucleotide arrays and robustified projection pursuit.
No sample metadata fields
View Samples