chiniofon and Kidney-Diseases

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

A case of artifactual multifocal lung activity presumably due to emboli of In-111 labeled leukocytes is described. These may have been caused by infusion through an intravenous line containing glucose, or by a minute amount of blood clotted in the needle. When administration through an existing intravenous line is necessary, flushing with saline before and after cell infusion is recommended to avoid this potential pitfall. A fresh needle also should be used for each venipuncture attempt.

Topics: Abscess; Aged; Aged, 80 and over; Female; Humans; Hydroxyquinolines; Indium Radioisotopes; Kidney Diseases; Leukocytes; Lung; Organometallic Compounds; Oxyquinoline; Radionuclide Imaging

The use of a 111indium oxine-leukocyte scan (white cell scan) to establish the diagnosis of a pyeloduodenal fistula is described. The patient had a fistula that was associated with spontaneous disappearance of a large staghorn calculus in the involved kidney. The disappearance of the calculus and the presence of a pyeloduodenal fistula were confirmed at surgical exploration. Although neither an excretory urogram nor a retrograde pyelogram was useful to diagnose the fistula preoperatively a 111indium oxine-leukocyte scan revealed the renal abscess and pyeloduodenal fistula.

Topics: Adult; Duodenal Diseases; Humans; Hydroxyquinolines; Indium; Intestinal Fistula; Kidney Calculi; Kidney Diseases; Leukocytes; Male; Organometallic Compounds; Oxyquinoline; Radiography; Radionuclide Imaging; Urinary Fistula

The influence of antidiuretic hormone (ADH) and papaverine on hydroxyquinoline-induced nephropathy in rats was tested, using histotopochemistry, enzyme activity measurement and morphometric investigation. Hydroxyquinoline causes a marked increase in renal weight, the development of wedge-shaped foci with severely dilated tubule segments, and a simultaneous reduction in dehydrogenases, alkaline phosphatase, and alpha-naphthyl esterase. Both ADH and papaverine produced a significant inhibition of renal damage. The subjective findings were quantitatively confirmed by measurement of enzyme activity, using the microscope photometer, and by morphometric studies with the Leitz-Classimat (determination on the basis of the alkaline phosphatase reaction) of the surface percentage of brush border in the proximal tubules. A disturbance of the hairpin counter-current system is to be considered as the cause of the renal lesion. This disturbance is caused by hydroxyquinoline-induced impairment of Na+/K+ transport, especially in the thick ascending limb of Henle's loop. Our results show that the hydroxyquinoline nephropathy can be favourably influenced both by stimulation of water re-absorption and possibly also transepithelial Na+ transport (ADH), and by increasing the blood flow of the arteriolae rectae with a resultant lowering of the intratubular urine concentration (papaverine). The dependency of hydroxyquinoline nephropathy on the phylogenetically determined concentration capacity of the kidney, and the effective influencing of the condition by ADH and papaverine indicate the importance of the degree of efficiency of the medullary countercurrent system in the pathogenesis of this renal lesion.

Topics: Alkaline Phosphatase; Animals; Esterases; Female; Histocytochemistry; Hydroxyquinolines; Kidney; Kidney Diseases; Kidney Tubules, Proximal; Organ Size; Oxidoreductases; Papaverine; Rats; Rats, Inbred Strains; Vasopressins

Topics: Bismuth; Cardiovascular Diseases; Diazepam; Drug Therapy; Endocrine System Diseases; Gastrointestinal Diseases; Glafenine; Hepatitis; Humans; Hydroxyquinolines; Hypersensitivity; Infections; Kidney Diseases; Metabolic Diseases; Neoplasms; Nervous System Diseases; Practolol; Respiratory Tract Diseases; Rheumatic Diseases