PMID- 9231765
OWN - NLM
STAT- MEDLINE
DCOM- 19970815
LR  - 20131121
IS  - 0013-7227 (Print)
IS  - 0013-7227 (Linking)
VI  - 138
IP  - 8
DP  - 1997 Aug
TI  - Retinoid X receptors in the kidney: their protein expression and functional 
      significance.
PG  - 3175-80
AB  - Retinoid X receptors (RXRs) heterodimerize with 1,25-dihydroxyvitamin D3 (VD) 
      receptor (VDR), and play important roles in VD-regulated transactivation. VD acts 
      on many tissues including kidney for the regulation of calcium homeostasis. In 
      the kidney, the expression of VDR in the tubular cells has been well studied. In 
      contrast, little is known about the localization and the functional significance 
      of RXRs there. In order to elucidate these questions, we first performed 
      immunohistochemical analyses of rat kidney using isoform-specific antimouse RXR 
      antibodies we have previously reported. Interestingly, all RXR isoforms, 
      predominantly RXR alpha, mainly localized to the proximal and the distal tubules, 
      but not to the glomeruli. The serial section staining using anti-VDR antibody 
      showed the colocalization of RXR alpha and VDR in those tubular cells. In order 
      to elucidate the functional significance of endogenous receptors in the tubular 
      cells, we next performed transient transfection studies using the tubular-cell 
      derived Madin-Darby bovine kidney cells, which express both endogenous VDR and 
      RXR. We transfected a reporter plasmid containing direct repeat 3 (DR3) sequence, 
      to which only RXR/VDR heterodimer can bind, and found that VD and 9-cis retinoic 
      acid, as well as VD and RXR selective agonist LG100153, had an additive effect 
      for the DR3 transactivation. Taken together, we speculate that endogenous RXRs 
      co-localize with VDR, and coregulate VD-dependent genes in the tubular cells of 
      the kidney as RXR/VDR heterodimer.
FAU - Sugawara, A
AU  - Sugawara A
AD  - The 2nd Department of Internal Medicine, Tohoku University School of Medicine, 
      Aoba-ku, Sendai, Japan.
FAU - Sanno, N
AU  - Sanno N
FAU - Takahashi, N
AU  - Takahashi N
FAU - Osamura, R Y
AU  - Osamura RY
FAU - Abe, K
AU  - Abe K
LA  - eng
PT  - Journal Article
PL  - United States
TA  - Endocrinology
JT  - Endocrinology
JID - 0375040
RN  - 0 (Oligonucleotides)
RN  - 0 (Receptors, Calcitriol)
RN  - 0 (Receptors, Retinoic Acid)
RN  - 0 (Retinoid X Receptors)
RN  - 0 (Transcription Factors)
RN  - 5688UTC01R (Tretinoin)
RN  - SY7Q814VUP (Calcium)
SB  - IM
MH  - Animals
MH  - Base Sequence
MH  - Blotting, Western
MH  - Calcium/metabolism
MH  - Cattle
MH  - Cell Line
MH  - Gene Expression Regulation
MH  - Homeostasis
MH  - Immunohistochemistry
MH  - Isomerism
MH  - Kidney/*chemistry/cytology/metabolism
MH  - Male
MH  - Oligonucleotides/analysis/chemistry/genetics
MH  - Rats
MH  - Rats, Wistar
MH  - Receptors, Calcitriol/analysis/genetics/physiology
MH  - Receptors, Retinoic Acid/*analysis/*genetics/physiology
MH  - Retinoid X Receptors
MH  - Transcription Factors/*analysis/*genetics/physiology
MH  - Transfection
MH  - Tretinoin/pharmacology
EDAT- 1997/08/01 00:00
MHDA- 1997/08/01 00:01
CRDT- 1997/08/01 00:00
PHST- 1997/08/01 00:00 [pubmed]
PHST- 1997/08/01 00:01 [medline]
PHST- 1997/08/01 00:00 [entrez]
AID - 10.1210/endo.138.8.5351 [doi]
PST - ppublish
SO  - Endocrinology. 1997 Aug;138(8):3175-80. doi: 10.1210/endo.138.8.5351.