Korean J Nephrol.  2011 May;30(3):239-245.

Potassium Depletion Upregulates Expression of Nrf2 Transcription Factor in Rat Kidney

• Lim JS
• Ahn KY

Abstract

PURPOSE
The purpose of this study was to analyze the expression and localization of Nrf2 mRNA in rats according to the changes of K-diet.
METHODS
Nrf2 gene was isolated using DNA chip microassay. Northern and Western blot analysis and in situ hybridization (ISH) were performed.
RESULTS
Northern analysis of normal rat demonstrated that Nrf2 mRNA was abundantly expressed in stomach, moderately in testis, kidney, distal colon, duodenum, and adrenal gland, and weakly in brain, heart, spleen, salivary gland, liver, and lung. In the kidney of K-restricted groups, Nrf2 mRNA and protein expressions were gradually increased in K-restricted kidney. By ISH, hybridization signal for Nrf2 gene of normal group was prominent in the S3 segment of proximal tubule, distal tubule, and cortical collecting duct, and weak in outer and inner medullary collecting duct. In K-restricted groups, the localization of hybridization signal was the same as in normal group. Signal intensity of K-restricted groups was markedly increased in outer and inner medullary collecting ducts compared with normal group. But, that of the distal tubule and cortical collecting duct was decreased. mRNA for Nrf2 gene of normal group was detected in the cells of the basal portion of intestinal gland of distal colon and stomach, spermatogonia and spermatocytes of seminiferous tubule of testis, small lymphocytes of germinal center of spleen, and adrenal medulla cells of adrenal gland.
CONCLUSION
These results suggest that expression of Nrf2 is different in various tissues and increased expression of Nrf2 gene in outer and inner medullary collecting ducts of hypokalemic kidney could regulate the ion transporter genes by these segments.

Keyword

Hypokalemia; NF-E2-related factor 2 (Nrf2); Transcription factor; In situ Hybridization

MeSH Terms

Adrenal Glands
Adrenal Medulla
Animals
Blotting, Western
Brain
Chimera
Colon
Duodenum
Germinal Center
Heart
Hypokalemia
In Situ Hybridization
Intestinal Mucosa
Ion Transport
Kidney
Liver
Lung
Lymphocytes
Oligonucleotide Array Sequence Analysis
Potassium
Rats
RNA, Messenger
Salivary Glands
Seminiferous Tubules
Spermatocytes
Spermatogonia
Spleen
Stomach
Testis
Transcription Factors
Potassium
RNA, Messenger
Transcription Factors