An efficient and versatile system for acute and chronic modulation of renal tubular function in transgenic mice

Abstract

We describe a transgenic mouse line, Pax8-rtTA, which, under control of the mouse Pax8 promoter, directs high levels of expression of the reverse tetracycline–dependent transactivator (rtTA) to all proximal and distal tubules and the entire collecting duct system of both embryonic and adult kidneys. Using crosses of Pax8-rtTA mice with tetracycline-responsive c-MYC mice, we established a new, inducible model of polycystic kidney disease that can mimic adult onset and that shows progression to renal malignant disease. When targeting the expression of transforming growth factor-β1 to the kidney, we avoided early lethality by discontinuous treatment and successfully established an inducible model of renal fibrosis. Finally, a conditional knockout of the gene encoding tuberous sclerosis complex-1 was achieved, which resulted in the early outgrowth of giant polycystic kidneys reminiscent of autosomal recessive polycystic kidney disease. These experiments establish Pax8-rtTA mice as a powerful tool for modeling renal diseases in transgenic mice.

Synchronized renal tubular cell death involves ferroptosis

“…FADD fl/fl mice were generated by and provided by M.P. Doxycyclin-inducible renal tubule-specific Pax8-rtTA; Tet-on.Cre mice have been published (28) and were kindly provided by Tobias B. Huber (Renal Division, University Medical Center Freiburg, Freiburg, Germany). RIPK3-deficient mice were kindly provided by Vishva M. Dixit (Genentech, San Francisco, CA).…”

Nephron‐Specific Disruption of Nitric Oxide Synthase 3 Causes Hypertension and Impaired Salt Excretion

“…Recombination of the NOS3 gene was detected in liver and kidney of NOS3 KO mice, consistent with the expected organ recombination pattern using the Pax8‐rtTA/LC‐1 system (Figure 1). 14, 15 …”

“…A targeting construct was made wherein exons 9 to 12 of the NOS3 gene were flanked by 2 loxP sites; recombination deletes the calmodulin biding site resulting in a non‐functional NOS3 protein. To generate inducible nephron‐specific NOS3 KO mice, floxed NOS3 mice were bred with mice containing the Pax8‐reverse tetracycline transactivator (rtTA) (Pax8 promoter‐rtTA confers nephron‐specific targeting) and LC‐1 transgenes (LC‐1 transgene contains doxycyline/rtTA‐inducible Cre recombinase and luciferase) 14, 15. Mice used in the studies were homozygous for the loxP‐flanked NOS3 gene and hemizygous for Pax8‐rtTA and LC‐1 transgenes.…”

Transgenic mice and their impact on kidney research

“…Here, the transgene is expressed specifically in the renal proximal tubule in male mice, but not expressed in females unless induced by testosterone [53]. Another efficient and versatile tool for acute and chronic modulation of renal tubular function in transgenic mice has been recently described by Traykova-Brauch and coworkers [108]. They generated Pax8::rtTA mice which strongly express the transgene in a highly kidney-specific, uniform and tetracycline-dependent manner.…”

“…We further concluded that aldosterone-regulated ENaC activity might occur more proximal in the early ASDN. Further tools to dissect ENaC function along the nephron include the AQP2::Cre mice that have been recently used to knockout the mineralocorticoid MR receptor in the CNT and CCD (Christensen et al, manuscript in preparation; [83]) and the Pax8::rtTA/LC1::Cre double transgenic line [108], that should eliminate ENaC function in all kidney cells with exception of glomeruli when bred to the floxed αENaC mice (Scnn1a flox ). Elimination of ENaC in the whole kidney will certainly indicate to which extent the kidney contributes to the whole net sodium homeostasis of the body.…”