title: 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.affiliation: Department of Genetics, Rutgers University, Piscataway, New Jersey 08854, USA.
authors.forename: Eleni G
authors.initials: EG
authors.lastname: Tzortzaki
authors.forename: Dayna
authors.initials: D
authors.lastname: Glass
authors.forename: Min
authors.initials: M
authors.lastname: Yang
authors.forename: Andrew P
authors.initials: AP
authors.lastname: Evan
authors.forename: Sharon B
authors.initials: SB
authors.lastname: Bledsoe
authors.forename: Peter J
authors.initials: PJ
authors.lastname: Stambrook
authors.forename: Amrik
authors.initials: A
authors.lastname: Sahota
authors.forename: Jay A
authors.initials: JA
authors.lastname: Tischfield
mesh_terms: D000228:Adenine Phosphoribosyltransferase / Q000172:deficiency / Q000235:genetics; D000367:Age Factors; D000818:Animals; D005260:Female; D005838:Genotype; D017403:In Situ Hybridization; D007668:Kidney / Q000378:metabolism*; D007669:Kidney Calculi / Q000378:metabolism*; D008297:Male; D051379:Mice; D018345:Mice, Knockout; D014176:Protein Biosynthesis; D011506:Proteins / Q000235:genetics; D012333:RNA, Messenger / Q000096:biosynthesis*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012737:Sex Factors
chemical_list: C067670:Kap protein, mouse; D011506:Proteins; D012333:RNA, Messenger; D000228:Adenine Phosphoribosyltransferase