Mutation of hepatocyte nuclear factor–1β inhibits Pkhd1 gene expression and produces renal cysts in mice
Thomas Hiesberger, … , Stefan Somlo, Peter Igarashi
Thomas Hiesberger, … , Stefan Somlo, Peter Igarashi
Published March 15, 2004
Citation Information: J Clin Invest. 2004;113(6):814-825. https://doi.org/10.1172/JCI20083.
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Article Nephrology

Mutation of hepatocyte nuclear factor–1β inhibits Pkhd1 gene expression and produces renal cysts in mice

Abstract

Hepatocyte nuclear factor–1β (HNF-1β) is a Pit-1, Oct-1/2, UNC-86 (POU)/homeodomain-containing transcription factor that regulates tissue-specific gene expression in the liver, kidney, and other organs. Humans with autosomal dominant mutations of HNF-1β develop maturity-onset diabetes of the young type 5 (MODY5) and congenital cystic abnormalities of the kidney. Autosomal recessive polycystic kidney disease (ARPKD) is an inherited cystic disorder that produces renal failure in infants and children and is caused by mutations of PKHD1. The proximal promoter of the mouse Pkhd1 gene contains an evolutionarily conserved HNF-1–binding site that is located near a region of deoxyribonuclease hypersensitivity. HNF-1β and the structurally related HNF-1α bind specifically to the Pkhd1 promoter and stimulate gene transcription. Mutations of the HNF-1 site or expression of a dominant-negative HNF-1β mutant inhibit Pkhd1 promoter activity in transfected cells. Transgenic mice expressing a dominant-negative HNF-1β mutant under the control of a kidney-specific promoter develop renal cysts, similarly to humans with MODY5. Pkhd1 transcripts are absent in the cells lining the cysts but are present in morphologically normal surrounding tubules. These studies identify a link between two cystic disease genes, HNF1β (MODY5) and PKHD1 (ARPKD). HNF-1β directly regulates the transcription of Pkhd1, and inhibition of PKHD1 gene expression may contribute to the formation of renal cysts in humans with MODY5.

Authors

Thomas Hiesberger, Yun Bai, Xinli Shao, Brian T. McNally, Angus M. Sinclair, Xin Tian, Stefan Somlo, Peter Igarashi

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Figure 1

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Sequence of the Pkhd1 promoter. (A) Alignment of the mouse (upper) and h...
Sequence of the Pkhd1 promoter. (A) Alignment of the mouse (upper) and human (lower) Pkhd1 promoters. Short vertical line indicates identity. Dash indicates gaps introduced to optimize the alignment. Bent arrow indicates the transcription initiation site at +1. Solid underlines indicate exon 1. Dashed underlines indicate the DNA fragment used for EMSA. Boxes indicate evolutionarily conserved transcription factor–binding sites identified using the ConSite program (conservation 75%, window 50, transcription factor threshold 80%). Nucleotides in bold type indicate the site-directed mutations M1–M3. The sequence of the mouse Pkhd1 promoter has been deposited in the GenBank database (accession number AY544205). (B) Mapping of the transcription initiation site by primer extension. Arrows indicate products corresponding to transcription initiation sites at +1 (144 bp) and +17 (128 bp) in kidney RNA (lanes 2 and 3) but not in yeast tRNA (lane 1). (C) Plot of the percentage of identity between the mouse (blue) and human (green) promoters. Horizontal line indicates 75% identity.