Inducible podocyte-specific gene expression in transgenic mice.
The podocyte plays a key role in glomerular function and glomerular disease. To facilitate studies of podocyte function, we have developed a transgenic mouse model with inducible expression in the podocyte. The tetracycline-inducible transgenic system facilitates gene expression with restricted cellular distribution and tight temporal control. Recently, Bujard and colleagues have developed a functionally improved reverse tetracycline-controlled transcriptional activator (rtTA) with substantially lower background in the off state (the absence of tetracycline) and greater inducibility in the on state (the presence of tetracycline). We used the human podocin (NPHS2) gene promoter to control expression of the rtTA cassette and bred these mice with a reporter mouse line that contains the cytomegalovirus minimal promoter and tetO promoter elements together with LacZ, encoding beta-galactosidase. Dual transgenic mice, bearing both podocin-rtTA and tetO-LacZ transgenes, had no detectable expression in kidney or other organs in the absence of tetracycline. Administration of tetracycline in the drinking water was associated with podocyte expression of beta-galactosidase, in a fashion that was time dependent (maximal at 1 wk) and dose-dependent (maximal at 2 mg/ml). Podocyte expression was confirmed in two ways: histochemical staining for beta-galactosidase and double-immunostaining using the podocyte marker WT-1 and beta-galactosidase. This transgenic system should aid future investigations of podocyte function.
Shigehara
Tetsuya
T
*Kidney Disease Section, Metabolic Diseases Branch, National Institutes of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Department of Health and Human Services, Bethesda, Maryland; and Department of Internal Medicine, University of Michigan Medical School, Ann Arbor, Michigan.
Zaragoza
Concepcion
C
*Kidney Disease Section, Metabolic Diseases Branch, National Institutes of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Department of Health and Human Services, Bethesda, Maryland; and Department of Internal Medicine, University of Michigan Medical School, Ann Arbor, Michigan.
Kitiyakara
Chagriya
C
*Kidney Disease Section, Metabolic Diseases Branch, National Institutes of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Department of Health and Human Services, Bethesda, Maryland; and Department of Internal Medicine, University of Michigan Medical School, Ann Arbor, Michigan.
Takahashi
Hideko
H
*Kidney Disease Section, Metabolic Diseases Branch, National Institutes of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Department of Health and Human Services, Bethesda, Maryland; and Department of Internal Medicine, University of Michigan Medical School, Ann Arbor, Michigan.
Lu
Huiyan
H
*Kidney Disease Section, Metabolic Diseases Branch, National Institutes of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Department of Health and Human Services, Bethesda, Maryland; and Department of Internal Medicine, University of Michigan Medical School, Ann Arbor, Michigan.
Moeller
Marcus
M
*Kidney Disease Section, Metabolic Diseases Branch, National Institutes of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Department of Health and Human Services, Bethesda, Maryland; and Department of Internal Medicine, University of Michigan Medical School, Ann Arbor, Michigan.
Holzman
Lawrence B
LB
*Kidney Disease Section, Metabolic Diseases Branch, National Institutes of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Department of Health and Human Services, Bethesda, Maryland; and Department of Internal Medicine, University of Michigan Medical School, Ann Arbor, Michigan.
Kopp
Jeffrey B
JB
*Kidney Disease Section, Metabolic Diseases Branch, National Institutes of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Department of Health and Human Services, Bethesda, Maryland; and Department of Internal Medicine, University of Michigan Medical School, Ann Arbor, Michigan.
D000818:Animals; D003587:Cytomegalovirus / Q000235:genetics; D004247:DNA / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D004318:Doxycycline / Q000494:pharmacology; D005786:Gene Expression Regulation; D017930:Genes, Reporter; D006801:Humans; D007668:Kidney / Q000378:metabolism; D007678:Kidney Glomerulus / Q000166:cytology*; D007763:Lac Operon; D051379:Mice; D008822:Mice, Transgenic; D008856:Microscopy, Fluorescence; D010957:Plasmids / Q000378:metabolism; D016133:Polymerase Chain Reaction; D011401:Promoter Regions, Genetic; D017434:Protein Structure, Tertiary; D013752:Tetracycline / Q000378:metabolism / Q000494:pharmacology; D013997:Time Factors; D014018:Tissue Distribution; D014158:Transcription, Genetic; D015533:Transcriptional Activation; D019076:Transgenes; D001616:beta-Galactosidase / Q000378:metabolism
D004247:DNA; D001616:beta-Galactosidase; D013752:Tetracycline; D004318:Doxycycline