RT-PCR microlocalization of mRNAs for calbindin D28k and vitamin D receptor in the murine nephron
Liu, L.; Khastgir, A.; McCauley, J.M.; Dunn, S.T.; Morrissey, J.H.; Christakos, S.; Hughes, M.R.; Bourdeau, J.E.
American Journal of Physiology 270(4 Pt 2): F677-F681
1996
ISSN/ISBN: 0002-9513 PMID: 8967346 Document Number: 460385
The spatial relationship between vitamin D receptor (VDR) and calbindin D-28k (calcium binding protein D-28k (CaBP-D-28k)) gene expression within the murine kidney was studied by localizing their mRNAs in discrete nephron structures using reverse transcription-polymerase chain reaction (RT-PCR). Primers for beta-actin mRNA were used as a control for the presence of tissue during RT-PCR for CaBP-D-28k mRNA. mRNA for CaBP-D-28k was found only in distal convoluted tubules (DCTs), connecting tubules (CNTs), and cortical collecting ducts (CCDs). In contrast, VDR mRNA was detected in glomeruli, S2 proximal convoluted tubules, cortical thick ascending limbs of Henle's loop, DCTs, CNTs, and initial CCDs. The presence of both VDR and CaBP-D-28k mRNA in DCTs, CNTs, and CCDs is consistent with the hypothesis that calcitriol acts via the VDR to stimulate CaBP-D-28k synthesis. Conversely, the presence of VDR mRNA in other parts of the nephron suggests that calcitriol has genomically mediated actions within the kidney in addition to stimulation of CaBP-D-28k synthesis.