Epigenetic Methylation of Parathyroid CaR and VDR Promoters in Experimental Secondary Hyperparathyroidism
Secondary hyperparathyroidism (s-HPT) in uremia is characterized by decreased expression in the parathyroids of calcium sensing (CaR) and vitamin D receptors (VDR). Parathyroid hormone (PTH) is normalized despite low levels of CaR and VDR after experimental reversal of uremia. The expression of CaR...
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| Format: | Article |
| Language: | English |
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Wiley
2012-01-01
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| Series: | International Journal of Nephrology |
| Online Access: | http://dx.doi.org/10.1155/2012/123576 |
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| author | Jacob Hofman-Bang Eva Gravesen Klaus Olgaard Ewa Lewin |
| author_facet | Jacob Hofman-Bang Eva Gravesen Klaus Olgaard Ewa Lewin |
| author_sort | Jacob Hofman-Bang |
| collection | DOAJ |
| description | Secondary hyperparathyroidism (s-HPT) in uremia is characterized by decreased expression in the parathyroids of calcium sensing (CaR) and vitamin D receptors (VDR). Parathyroid hormone (PTH) is normalized despite low levels of CaR and VDR after experimental reversal of uremia. The expression of CaR in parathyroid cultures decreases rapidly. Methylation of promoter regions is often detected during epigenetic downregulation of gene expression. Therefore, using an experimental rat model, we examined changes in methylation levels of parathyroid CaR and VDR promoters in vivo and in vitro. Methods. Uremia was induced by 5/6 nephrectomy. Melting temperature profiling of CaR and VDR PCR products after bisulfite treatment of genomic DNA from rat parathyroids was performed. Real-time PCR measured expression of PTH, CaR, VDR, and klotho genes in vitro. Results. Parathyroids from uremic rats had similar low levels of methylation in vivo and in vitro. In culture, a significant downregulation of CaR, VDR, and klotho within two hours of incubation was observed, while housekeeping genes remained stable for 24 hours. Conclusion. In uremic s-HPT and in vitro, no overall changes in methylation levels in the promoter regions of parathyroid CaR and VDR genes were found. Thus, epigenetic methylation of these promoters does not explain decreased parathyroid expression of CaR and VDR genes in uremic s-HPT. |
| format | Article |
| id | doaj-art-a825ec98176b4e5d8c21f61ffd9b1772 |
| institution | Kabale University |
| issn | 2090-214X 2090-2158 |
| language | English |
| publishDate | 2012-01-01 |
| publisher | Wiley |
| record_format | Article |
| series | International Journal of Nephrology |
| spelling | doaj-art-a825ec98176b4e5d8c21f61ffd9b17722025-02-03T05:51:06ZengWileyInternational Journal of Nephrology2090-214X2090-21582012-01-01201210.1155/2012/123576123576Epigenetic Methylation of Parathyroid CaR and VDR Promoters in Experimental Secondary HyperparathyroidismJacob Hofman-Bang0Eva Gravesen1Klaus Olgaard2Ewa Lewin3Nephrological Department P2132, Rigshospitalet, Herlev Hospital, University of Copenhagen, 9 Blegdamsvej, 2100 Copenhagen, DenmarkNephrological Department P2132, Rigshospitalet, Herlev Hospital, University of Copenhagen, 9 Blegdamsvej, 2100 Copenhagen, DenmarkNephrological Department P2132, Rigshospitalet, Herlev Hospital, University of Copenhagen, 9 Blegdamsvej, 2100 Copenhagen, DenmarkNephrological Department P2132, Rigshospitalet, Herlev Hospital, University of Copenhagen, 9 Blegdamsvej, 2100 Copenhagen, DenmarkSecondary hyperparathyroidism (s-HPT) in uremia is characterized by decreased expression in the parathyroids of calcium sensing (CaR) and vitamin D receptors (VDR). Parathyroid hormone (PTH) is normalized despite low levels of CaR and VDR after experimental reversal of uremia. The expression of CaR in parathyroid cultures decreases rapidly. Methylation of promoter regions is often detected during epigenetic downregulation of gene expression. Therefore, using an experimental rat model, we examined changes in methylation levels of parathyroid CaR and VDR promoters in vivo and in vitro. Methods. Uremia was induced by 5/6 nephrectomy. Melting temperature profiling of CaR and VDR PCR products after bisulfite treatment of genomic DNA from rat parathyroids was performed. Real-time PCR measured expression of PTH, CaR, VDR, and klotho genes in vitro. Results. Parathyroids from uremic rats had similar low levels of methylation in vivo and in vitro. In culture, a significant downregulation of CaR, VDR, and klotho within two hours of incubation was observed, while housekeeping genes remained stable for 24 hours. Conclusion. In uremic s-HPT and in vitro, no overall changes in methylation levels in the promoter regions of parathyroid CaR and VDR genes were found. Thus, epigenetic methylation of these promoters does not explain decreased parathyroid expression of CaR and VDR genes in uremic s-HPT.http://dx.doi.org/10.1155/2012/123576 |
| spellingShingle | Jacob Hofman-Bang Eva Gravesen Klaus Olgaard Ewa Lewin Epigenetic Methylation of Parathyroid CaR and VDR Promoters in Experimental Secondary Hyperparathyroidism International Journal of Nephrology |
| title | Epigenetic Methylation of Parathyroid CaR and VDR Promoters in Experimental Secondary Hyperparathyroidism |
| title_full | Epigenetic Methylation of Parathyroid CaR and VDR Promoters in Experimental Secondary Hyperparathyroidism |
| title_fullStr | Epigenetic Methylation of Parathyroid CaR and VDR Promoters in Experimental Secondary Hyperparathyroidism |
| title_full_unstemmed | Epigenetic Methylation of Parathyroid CaR and VDR Promoters in Experimental Secondary Hyperparathyroidism |
| title_short | Epigenetic Methylation of Parathyroid CaR and VDR Promoters in Experimental Secondary Hyperparathyroidism |
| title_sort | epigenetic methylation of parathyroid car and vdr promoters in experimental secondary hyperparathyroidism |
| url | http://dx.doi.org/10.1155/2012/123576 |
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