Distinct, Tissue-Specific Regulation of Vitamin D Receptor in the Intestine, Kidney, and Skin by Dietary Calcium and Vitamin D
We studied the effects of vitamin D deficiency and its correction by vitamin D or calcium-lactose supplementation on vitamin D receptor (VDR) expression in skin keratinocytes, kidney, and duodenum of adult rats. VDR messenger RNA (mRNA) was assayed by Northern blot, and VDR protein was determined im...
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Published in | Endocrinology (Philadelphia) Vol. 139; no. 4; pp. 1844 - 1852 |
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Main Authors | , , , |
Format | Journal Article |
Language | English |
Published |
Endocrine Society
01.04.1998
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Online Access | Get full text |
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Summary: | We studied the effects of vitamin D deficiency and its correction by
vitamin D or calcium-lactose supplementation on vitamin D receptor
(VDR) expression in skin keratinocytes, kidney, and duodenum of adult
rats. VDR messenger RNA (mRNA) was assayed by Northern blot, and VDR
protein was determined immunocytochemically. In addition, four
subpopulations of keratinocytes were isolated, characterized for their
stages of differentiation, and analyzed for VDR expression. Vitamin D
deficiency decreased VDR mRNA in all three tissues. Treatment with
vitamin D or calcium-lactose reestablished the VDR mRNA content of the
epidermis, but not that of the kidneys, and only the calcium-lactose
diet increased duodenal VDR mRNA. The regulation of VDR mRNA in the
epidermis was independent of cell differentiation, whereas VDR protein
varied with differentiation. The VDR-positive cells in the control rats
were at early and advanced states of differentiation. The expression of
VDR was decreased by vitamin D deficiency and returned to control
values after vitamin D or calcium supplementation. Vitamin D treatment,
but not calcium, induced VDR expression in the normally immature
population. Vitamin D and calcium, therefore, have distinct,
tissue-specific effects on VDR. In epidermis, the posttranscriptional
regulation of VDR expression is linked to cell differentiation. Calcium
may be a key factor for VDR transcription, whereas both vitamin D and
calcium seem to contribute to its posttranscriptional regulation. |
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ISSN: | 0013-7227 1945-7170 |
DOI: | 10.1210/endo.139.4.5903 |