chiniofon and Proteinuria

Podocyte injury and loss mark an early step in the pathogenesis of various glomerular diseases, making these cells excellent targets for therapeutics. However, cell-based high-throughput screening assays for the rational development of podocyte-directed therapeutics are currently lacking. Here, we describe a novel high-content screening-based phenotypic assay that analyzes thousands of podocytes per assay condition in 96-well plates to quantitatively measure dose-dependent changes in multiple cellular features. Our assay consistently produced a Z' value >0.44, making it suitable for compound screening. On screening with >2100 pharmacologically active agents, we identified 24 small molecules that protected podocytes against injury in vitro (1% hit rate). Among the identified hits, we confirmed an β1-integrin agonist, pyrintegrin, as a podocyte-protective agent. Treatment with pyrintegrin prevented damage-induced decreases in F-actin stress fibers, focal adhesions, and active β1-integrin levels in cultured cells. In vivo, administration of pyrintegrin protected mice from LPS-induced podocyte foot process effacement and proteinuria. Analysis of the murine glomeruli showed that LPS administration reduced the levels of active β1 integrin in the podocytes, which was prevented by cotreatment with pyrintegrin. In rats, pyrintegrin reduced peak proteinuria caused by puromycin aminonucleoside-induced nephropathy. Our findings identify pyrintegrin as a potential therapeutic candidate and show the use of podocyte-based screening assays for identifying novel therapeutics for proteinuric kidney diseases.

Topics: Actins; Albuminuria; Animals; Cell Movement; Epithelial Cells; Focal Adhesions; High-Throughput Screening Assays; Hydroxyquinolines; Integrin beta1; Kidney Diseases; Kidney Glomerulus; Lipopolysaccharides; Mice; Microscopy, Confocal; Phenotype; Podocytes; Proteinuria; Puromycin Aminonucleoside; Rats; Sulfonamides

Naturally occurring CD4+CD25+ regulatory T (Treg) cells are central to the maintenance of peripheral tolerance. Impaired activity and/or a lower frequency of these cells lead to systemic lupus erythematosus (SLE). Manipulating the number or activity of Treg cells is to be a promising strategy in treating it and other autoimmune diseases. We have examined the effects of Y27, a novel derivative of 4-hydroxyquinoline-3-formamide, on SLE-like symptoms in MRL/lpr autoimmune mice and BDF1 hybrid mice. Whether the beneficial effect of Y27 involves modulation of CD4+CD25+ Treg cells has also been investigated.. Female MRL/lpr mice that spontaneously develop lupus were treated orally by gavage with Y27 for 10 weeks, starting at 10 weeks of age. BDF1 mice developed a chronic graft-versus-host disease (GVHD) by two weekly intravenous injections of parental female DBA/2 splenic lymphocytes, characterized by immunocomplex-mediated glomerulonephritis resembling SLE. Y27 was administered to chronic GVHD mice for 12 weeks. Nephritic symptoms were monitored and the percentage of CD4+CD25+FoxP3+ Treg peripheral blood leukocyte was detected with mouse regulatory T cell staining kit by flowcytometry. Purified CD4+CD25+ Tregs were assessed for immune suppressive activity using the mixed lymphocyte reaction.. The life-span of MRL/lpr mice treated with Y27 for 10 weeks was significantly prolonged, proteinuria and renal lesion severity were ameliorated, and blood urea nitrogen, triglyceride and serum anti-double-stranded DNA antibodies were decreased. Similar results were found in chronic GVHD mice. Administration of Y27 had little impact on percentage of the peripheral blood lymphocyte CD4+CD25+Foxp3+ Treg cells in both groups of mice. In contrast, the suppressive capacity of CD4+CD25+ Treg cells in splenocytes was markedly augmented in Y27-treated mice ex vivo.. Experimental evidence of the protect effects of Y27 against autoimmune nephritis has been shown. The mechanism may involve enhancement of the suppressive capacity of CD4+CD25+ Treg cells.

Topics: Administration, Oral; Adoptive Transfer; Animals; Autoantibodies; Chronic Disease; Enzyme-Linked Immunosorbent Assay; Female; Forkhead Transcription Factors; Formamides; Glomerulonephritis; Graft vs Host Disease; Hydroxyquinolines; Interleukin-10; Interleukin-2 Receptor alpha Subunit; Kidney; Lupus Erythematosus, Systemic; Mice, Inbred CBA; Mice, Inbred DBA; Mice, Inbred MRL lpr; Molecular Structure; Proteinuria; T-Lymphocytes, Regulatory; Transforming Growth Factor beta1

Roquinimex is an immunomodulator that can effectively inhibit the development of several autoimmune diseases in animal models, but the mechanism is still unknown. In this study, we investigated the effect of roquinimex on chronic graft-versus-host disease (GVHD) in mice, a well-established model for human systemic lupus erythematosus (SLE). Oral administration of roquinimex significantly suppressed the development of proteinuria and ameliorated nephritis symptoms in chronic GVHD mice. In addition, renal histopathology and immunohistochemistry studies revealed reduced glomerulonephritis and decreased IgG deposition in chronic GVHD mice treated with roquinimex. Chronic GVHD is characterized by a predominance of Th2 cytokines, and proinflammatory cytokines that also play an important role in the pathology of tissue damage. Therefore, we focused on the effect of roquinimex on cytokine production. Chronic GVHD mouse splenocytes exhibited severely reduced interferon (IFN)-gamma production in response to Concanavalin (Con A) stimulation and an overt Th2 skewness. Roquinimex treatment, however, induced IFN-gamma production and restored the Th1/Th2 cytokine balance, although only a minimal effect of roquinimex on interleukin (IL)-4 secretion was observed. The production of the proinflammatory cytokines TNF-alpha and IL-1 beta by peritoneal macrophages from lipopolysaccharide (LPS)-treated GVHD mice was significantly inhibited by roquinimex treatment. These data suggested that the beneficial effect of roquinimex on lupus might, at least in part, result from a restoration of Th1/Th2 cytokine balance and inhibition of inflammatory cytokine production.

Topics: Adjuvants, Immunologic; Animals; Antibodies, Antinuclear; Blood Urea Nitrogen; Cells, Cultured; Cholesterol; Chronic Disease; Creatinine; Cytokines; Enzyme-Linked Immunosorbent Assay; Female; Graft vs Host Disease; Hydroxyquinolines; Immunoglobulin G; Inflammation Mediators; Kidney; Macrophages; Male; Mice; Mice, Inbred DBA; Proteinuria; Spleen; Th1 Cells; Th2 Cells; Triglycerides