title: Visualization of Calcium Dynamics in Kidney Proximal Tubules.
abstract: Intrarenal changes in cytoplasmic calcium levels have a key role in determining pathologic and pharmacologic responses in major kidney diseases. However, cell-specific delivery of calcium-sensitive probes in vivo remains problematic. We generated a transgenic rat stably expressing the green fluorescent protein-calmodulin-based genetically encoded calcium indicator (GCaMP2) predominantly in the kidney proximal tubules. The transposon-based method used allowed the generation of homozygous transgenic rats containing one copy of the transgene per allele with a defined insertion pattern, without genetic or phenotypic alterations. We applied in vitro confocal and in vivo two-photon microscopy to examine basal calcium levels and ligand- and drug-induced alterations in these levels in proximal tubular epithelial cells. Notably, renal ischemia induced a transient increase in cellular calcium, and reperfusion resulted in a secondary calcium load, which was significantly decreased by systemic administration of specific blockers of the angiotensin receptor and the Na-Ca exchanger. The parallel examination of in vivo cellular calcium dynamics and renal circulation by fluorescent probes opens new possibilities for physiologic and pharmacologic investigations.
authors: Institute of Enzymology, Research Centre for Natural Sciences, Hungarian Academy of Sciences, Budapest, Hungary;
authors: Kornélia
authors: K
authors: Szebényi
authors: Institute of Enzymology, Research Centre for Natural Sciences, Hungarian Academy of Sciences, Budapest, Hungary;
authors: András
authors: A
authors: Füredi
authors: Institute of Enzymology, Research Centre for Natural Sciences, Hungarian Academy of Sciences, Budapest, Hungary;
authors: Orsolya
authors: O
authors: Kolacsek
authors: First Department of Pediatrics.
authors: Rózsa
authors: R
authors: Csohány
authors: First Department of Pediatrics.
authors: Ágnes
authors: Á
authors: Prókai
authors: Department of Biophysics and Radiation Biology, MTA-SE Molecular Biophysics Research Group, and.
authors: Katalin
authors: K
authors: Kis-Petik
authors: MTA-SE, Pediatrics and Nephrology Research Group, Budapest, Hungary;
authors: Attila
authors: A
authors: Szabó
authors: NARIC-ABI, Gödöllö, Hungary;
authors: Zsuzsanna
authors: Z
authors: Bősze
authors: ImmunoGenes Kft., Budakeszi, Hungary; and.
authors: Balázs
authors: B
authors: Bender
authors: Department of Experimental Pharmacology, National Institute of Oncology, Budapest, Hungary.
authors: József
authors: J
authors: Tóvári
authors: Second Department of Pathology, Semmelweis University, Budapest, Hungary;
authors: Ágnes
authors: Á
authors: Enyedi
authors: Institute of Enzymology, Research Centre for Natural Sciences, Hungarian Academy of Sciences, Budapest, Hungary;
authors: Tamás I
authors: TI
authors: Orbán
authors: Institute of Enzymology, Research Centre for Natural Sciences, Hungarian Academy of Sciences, Budapest, Hungary; apati@biomembrane.hu sarkadi@biomembrane.hu.
authors: Ágota
authors: Á
authors: Apáti
authors: Institute of Enzymology, Research Centre for Natural Sciences, Hungarian Academy of Sciences, Budapest, Hungary; Department of Biophysics and Radiation Biology, MTA-SE Molecular Biophysics Research Group, and apati@biomembrane.hu sarkadi@biomembrane.hu.
authors: Balázs
authors: B
authors: Sarkadi
mesh_terms: D000818:Animals; D030801:Animals, Genetically Modified; D002118:Calcium / Q000378:metabolism*; D003593:Cytoplasm / Q000378:metabolism; D005260:Female; D049452:Green Fluorescent Proteins / Q000378:metabolism; D006720:Homozygote; D000860:Hypoxia / Q000473:pathology; D007511:Ischemia / Q000473:pathology; D007668:Kidney / Q000378:metabolism / Q000473:pathology; D007672:Kidney Cortex / Q000378:metabolism; D007674:Kidney Diseases / Q000473:pathology; D007684:Kidney Tubules / Q000378:metabolism; D007687:Kidney Tubules, Proximal / Q000378:metabolism* / Q000473:pathology; D008024:Ligands; D018613:Microscopy, Confocal; D051381:Rats; D015427:Reperfusion Injury; D019831:Sodium-Calcium Exchanger / Q000378:metabolism; D019076:Transgenes
chemical_list: D008024:Ligands; D019831:Sodium-Calcium Exchanger; C110374:sodium-calcium exchanger 1; D049452:Green Fluorescent Proteins; D002118:Calcium
keywords: calcium; hypoxia; ischemia-reperfusion; renal ischemia; renal proximal tubule cell