Targeted genomic deletions identify diverse enhancer functions and generate a kidney-specific, endocrine-deficient Cyp27b1 pseudo-null mouse
| Autor: | Martin Kaufmann, Seong Min Lee, Robert R. Redfield, Mark B. Meyer, Nancy A. Benkusky, J. Wesley Pike, Glenville Jones |
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| Rok vydání: | 2019 |
| Předmět: |
Male
0301 basic medicine Fibroblast growth factor 23 Parathyroid hormone Mice Transgenic Biology Kidney Biochemistry Mice 03 medical and health sciences CYP24A1 Animals Homeostasis Humans Gene Regulation Vitamin D Enhancer Molecular Biology Psychological repression 25-Hydroxyvitamin D3 1-alpha-Hydroxylase Mice Knockout Regulation of gene expression 030102 biochemistry & molecular biology Methyltransferases Cell Biology Phenotype Chromatin Cell biology Mice Inbred C57BL Fibroblast Growth Factor-23 Enhancer Elements Genetic 030104 developmental biology Calcium Female CRISPR-Cas Systems Gene Deletion |
| Zdroj: | J Biol Chem |
| ISSN: | 0021-9258 |
| DOI: | 10.1074/jbc.ra119.008760 |
| Popis: | Vitamin D(3) is terminally bioactivated in the kidney to 1α,25-dihydroxyvitamin D(3) (1,25(OH)(2)D(3)) via cytochrome P450 family 27 subfamily B member 1 (CYP27B1), whose gene is regulated by parathyroid hormone (PTH), fibroblast growth factor 23 (FGF23), and 1,25(OH)(2)D(3). Our recent genomic studies in the mouse have revealed a complex kidney-specific enhancer module within the introns of adjacent methyltransferase-like 1 (Mettl1) and Mettl21b that mediate basal and PTH-induced expression of Cyp27b1 and FGF23- and 1,25(OH)(2)D(3)-mediated repression. Gross deletion of these segments in mice has severe effects on Cyp27b1 regulation and skeletal phenotype but does not affect Cyp27b1 expression in nonrenal target cells (NRTCs). Here, we report a bimodal activity in the Mettl1 intronic enhancer with components responsible for PTH-mediated Cyp27b1 induction and 1,25(OH)(2)D(3)-mediated repression and additional activities, including FGF23 repression, within the Mettl21b enhancers. Deletion of both submodules eliminated basal Cyp27b1 expression and regulation in the kidney, leading to systemic and skeletal phenotypes similar to those of Cyp27b1-null mice. However, basal expression and lipopolysaccharide-induced regulation of Cyp27b1 in NRTCs was unperturbed. Importantly, dietary normalization of calcium, phosphate, PTH, and FGF23 rescued the skeletal phenotype of this mutant mouse, creating an ideal in vivo model to study nonrenal 1,25(OH)(2)D(3) production in health and disease. Finally, we confirmed a conserved chromatin landscape in human kidney that is similar to that in mouse. These findings define a finely balanced homeostatic mechanism involving PTH and FGF23 together with protection from 1,25(OH)(2)D(3) toxicity that is responsible for both adaptive vitamin D metabolism and mineral regulation. |
| Databáze: | OpenAIRE |
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