Faculty Collaboration Database

Oxygen-dependent expression of hypoxia-inducible factor-1alpha in renal medullary cells of rats. Physiol Genomics 2001 Aug 28;6(3):159-68

Date

08/30/2001

Pubmed ID

11526200

DOI

10.1152/physiolgenomics.2001.6.3.159

Scopus ID

2-s2.0-0347711871 (requires institutional sign-in at Scopus site)   52 Citations

Abstract

Hypoxia-inducible factor-1alpha (HIF-1alpha) is a transcription factor that regulates the oxygen-dependent expression of a number of genes. This transcription factor may contribute to the abundant expression of many genes in renal medullary cells that function normally under hypoxic conditions. The present study was designed to determine the characteristics of HIF-1alpha cDNA cloned from the rat kidney and the expression profile of HIF-1alpha in different kidney regions and to explore the mechanism activating or regulating HIF-1alpha expression in renal medullary cells. A 3,718-bp HIF-1alpha cDNA from the rat kidney was first cloned and sequenced using RT-PCR and TA cloning technique. It was found that 823 amino acids deduced from this renal HIF-1alpha cDNA had 99%, 96%, and 90% identity with rat, mouse, or human HIF-1alpha deposited in GenBank, respectively. The 3'-untranslated region of HIF-1alpha mRNA from the rat kidney contained seven AUUUA instability elements, five of which were found to be conserved among rat, mouse, and human HIF-1alpha. Northern blot analyses demonstrated a corticomedullary gradient of HIF-1alpha mRNA expression in the kidney, with the greatest abundance in the renal inner medulla. Western blot analyses also detected a higher HIF-1alpha protein level in the nuclear extracts from the renal medulla than the renal cortex. A classic loop diuretic, furosemide (10 mg/kg ip), markedly increased renal medullary Po(2) levels from 22.5 to 52.2 mmHg, which was accompanied by a significant reduction of HIF-1alpha transcripts in renal medullary tissue. In in vitro experiments, low Po(2), but not elevated osmolarity, was found to significantly increase HIF-1alpha mRNA in renal medullary interstitial cells and inner medullary collecting duct cells. These results indicate that HIF-1alpha is more abundantly expressed in the renal medulla compared with the renal cortex. Increased abundance of HIF-1alpha mRNA in the renal medulla may represent an adaptive response of renal medullary cells to low Po(2).

Author List

Zou AP, Yang ZZ, Li PL, Cowley AW JR

Author

Allen W. Cowley Jr PhD Professor in the Physiology department at Medical College of Wisconsin

MESH terms used to index this publication - Major topics in bold

3' Untranslated Regions
Amino Acid Sequence
Animals
Base Sequence
Blotting, Northern
Blotting, Western
Cell Hypoxia
Cloning, Molecular
DNA, Complementary
Diuretics
Furosemide
Gene Expression Regulation
Hypoxia-Inducible Factor 1, alpha Subunit
Kidney Cortex
Kidney Medulla
Molecular Sequence Data
Osmolar Concentration
Oxygen
RNA, Messenger
Rats
Sequence Alignment
Sequence Analysis, DNA
Sequence Homology, Amino Acid
Sequence Homology, Nucleic Acid
Sodium Chloride
Transcription Factors
Urea