Expression of Phosphatonin-Related Genes in Sheep, Dog and Horse Kidneys Using Quantitative Reverse Transcriptase PCR

Abstract

The aim of this preliminary study was to determine the relative expression of phosphatonin pathway-related genes in normal dog, sheep and horse kidneys and to explore the relationships between the different genes. Kidneys were collected post-mortem from 10 sheep, 10 horses and 8 dogs. RNA was extracted, followed by reverse transcriptase quantitative polymerase chain reaction for fibroblast growth factor receptor 1 IIIc (FGFR1IIIC), sodium-phosphate co-transporter (NPT) 1 (SLC17A1), NPT2a (SLC34A1), NPT2c (SLC34A3), parathyroid hormone 1 receptor (PTH1R), klotho (KL), vitamin D receptor (VDR), 1a-hydroxylase (CYP27B1) and 24-hydroxylase (CYP24A1). NPT2a was highly expressed in the dog kidneys, compared with those of the horses and sheep. NPT1 had greatest expression in horses and sheep, although the three different NPTs all had relatively similar expression in sheep. There was little variability in FGFR1IIIc expression, particularly in the dogs and horses. FGFR1IIIc expression was negatively correlated with NPT genes (except NPT2a in sheep), while NPT genes were all positively correlated with each other. Unexpectedly, klotho was positively correlated with NPT genes in all three species. These results provide the basis for further research into this important regulatory system. In particular, species differences in phosphatonin gene expression should be considered when considering the pathogenesis of chronic kidney disease.

Expression of Renal Vitamin D and Phosphatonin-Related Genes in a Sheep Model of Osteoporosis

“…Two previous studies have examined the separate relationships between vitamin D-responsive genes, and phosphatonin-related genes in sheep kidney [ 20 , 21 ]. However, relationships between the vitamin D and phosphatonin pathways have not been examined.…”

“…RNA extraction and qPCR were performed as previously described [ 20 , 21 ]. Briefly, Tri Reagent (Sigma-Aldrich Inc., Merck KGaA, Darmstadt, Germany) was used to extract RNA as per the manufacturer’s instructions.…”