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 SamplesThe specialized glomerular epithelial cell (podocyte) of the kidney is a complex cell that is often damaged in glomerular diseases. Study of this cell type is facilitated by an in vitro system of propagation of conditionally immortalized podocytes. Here, genes that are differentially expressed in this in vitro model of podocyte differentiation are evaluated.
No associated publication
Specimen part
View SamplesBackground: A subset of asthmatics does not respond to steroid therapy and therefore is at risk for escalation of disease severity. The cause of corticosteroid resistant (CR) asthma is unknown. Gene microarray technologies have the potential to substantiate new hypotheses regarding the etiology of corticosteroid resistance.
No associated publication
No sample metadata fields
View SamplesThe response of human neutrophils to the emerging pathogen Mycobacterium abscessus has not been described. However, M. abscessus infections are frequently associated with neutrophil-rich abscesses. To better understand the reponse of neutrophils to M. abscessus we performed gene expression analysis using Affymetrix HG-U133A Plus 2.0 microarrays. Human neutrophils from healthy donors were stimulated with isogenic rough and smooth morphotypes of M. abscessus. Staphylococcus aureus was used as a control. Gene expression was compared to neutrophils left unstimulated. Neutrophils from four individual donors were isolated on separate days and stimulated with freshly prepared bacteria. Neutrophils (stimulated and control) were left for 2 hours before total RNA was isolated, and biotinylated cRNA was prepared by standard methods. Analysis indicates that M. abscessus morphotypes induce a limited number of genes, when compared to S. aureus, which are enriched in genes for cytokines and chemokines, including neutrophil-specific chemokines. These data suggest that neutrophils have a limited response to M. abscessus, which may contribute to neutrophil-rich abscess formation.overall_design = Human neutrophils from healthy donors were exposed to rough Mab (ATCC 19977T), smooth Mab (ATCC 19977T) and S. aureus (CF clinical strain) for two hours; control cells were exposed to saline.
Mycobacterium abscessus induces a limited pattern of neutrophil activation that promotes pathogen survival.
Specimen part, Disease, Treatment
View SamplesWe performed gene expression profile of different B cell populations found in old (18 months old) C57BL/6 female mouse (B1 cells were recovered from both young and old C57BL/6 mice). Mice were nave and healthy (no autoimmunity was detected at the time of the experiment).
Toll-like receptor 7 (TLR7)-driven accumulation of a novel CD11c⁺ B-cell population is important for the development of autoimmunity.
Sex, Age, Specimen part
View SamplesTo determine HIF1a target genes in ATII cells, we transduced freshly isolated rat ATII cells with an adenoviral vector expressing either GFP or a constitutively active mutant HIF1a construct. After 24 hours, RNA was extracted and subjected to microarray.
No associated publication
Sex, Specimen part
View SamplesMacrophages phagocytose bacteria. Certain pathogenic bacteria access and replicate within the cytosol of infected macrophages and induce changes in macrophage gene expression by triggering of innate immune receptors and/or the effects of bacterial virulence factors. We used microarray analysis to identify changes in macrophage gene expression following infection with Listeria monocytogenes.
Induction of IFN-alphabeta enables Listeria monocytogenes to suppress macrophage activation by IFN-gamma.
Sex, Specimen part
View SamplesExpression data were generated on 136 subjects from the COPDGene study using Affymetrix microarrays. Multiple linear regression with adjustment for covariates (gender, age, body mass index, family history, smoking status, pack years) was used to identify candidate genes and Ingenuity Pathway Analysis was used to identify candidate pathways.
Peripheral blood mononuclear cell gene expression in chronic obstructive pulmonary disease.
Sex, Specimen part
View SamplesMany aged individuals develop monoclonal expansions of CD8 T cells. These expansions are derived from a CD8 memory T cell that outcompetes neighboring CD8 T cells. The molecular alterations within clonal expansions that confer this competitive advantage relative to other CD8 T cells remains unknown. These microarray experiments were designed to identify genes differentially expressed in age-associated expansions of CD8 memory T cells relative to polyclonal CD8 memory T cells found in the same aged mice.
Identification of two major types of age-associated CD8 clonal expansions with highly divergent properties.
No sample metadata fields
View SamplesA predictive gene list for response to high dose melphalan therapy in patients diagnosed with multiple myeloma is generated by combining results from dose response experiments and microarray data using a B-cell line panel and the introduction of multivariate regression techniques.
Generation of a predictive melphalan resistance index by drug screen of B-cell cancer cell lines.
Cell line
View Samples