Gender- and age-dependent changes in kidney androgen protein mRNA expression in a knockout mouse model for nephrolithiasis.

Abstract

Kidney androgen-regulated protein (Kap) is the most abundant protein in the mouse kidney, but its function is unknown. We previously observed a significant decrease in Kap mRNA expression in whole kidney tissue from male mice with adenine phosphoribosyltransferase (APRT) deficiency and 2,8-dihydroxyadenine (DHA) nephrolithiasis. The disease phenotype is more severe in male mice and is age-dependent. To identify the cellular basis for differential Kap expression, we used in situ hybridization (ISH) and reverse transcription-polymerase chain reaction ISH (RT-PCR ISH) to identify the cell types expressing this mRNA in paraffin-embedded kidney sections. In 1-month-old wild-type male mice, Kap was detected primarily in S3 proximal tubule segments, but expression was very low in female mice. In 1-month-old APRT-deficient male mice, Kap expression was decreased significantly and was undetectable in female mice. Kap mRNA was not detected in 3- or 6-month-old mice using our standard ISH protocol, but we observed intense cytoplasmic staining in S3 proximal tubules in wild-type male mice of these age groups using an improved RT-PCR ISH procedure. Our studies demonstrate age-, gender-, and APRT genotype-dependent changes in Kap mRNA expression in mouse kidney. Kap expression is under multihormonal control, and hormonal changes in DHA-induced nephrolithiasis may account for the decreased Kap expression in APRT-deficient mice.

• Authors: Eleni G Tzortzaki, Dayna Glass, Min Yang, Andrew P Evan, Sharon B Bledsoe, Peter J Stambrook, Amrik Sahota, Jay A Tischfield
• Journal: The journal of histochemistry and cytochemistry : official journal of the Histochemistry Society (J Histochem Cytochem) Vol. 50 Issue 12 Pg. 1663-9 (Dec 2002) ISSN: 0022-1554 [Print] United States
• PMID: 12486089 (Publication Type: Journal Article, Research Support, U.S. Gov't, P.H.S.)

Chemical References

• Kap protein, mouse
• Proteins
• RNA, Messenger
• Adenine Phosphoribosyltransferase

Topics

• Adenine Phosphoribosyltransferase (deficiency, genetics)
• Age Factors
• Animals
• Female
• Genotype
• In Situ Hybridization
• Kidney (metabolism)
• Kidney Calculi (metabolism)
• Male
• Mice
• Mice, Knockout
• Protein Biosynthesis
• Proteins (genetics)
• RNA, Messenger (biosynthesis)
• Reverse Transcriptase Polymerase Chain Reaction
• Sex Factors