Fibroblast growth factor 23 counters vitamin D metabolism and action in human mesenchymal stem cells. Issue 199 (May 2020)

• Record Type: Journal Article
• Authors: Meng, Fangang; Bertucci, Christopher; Gao, Yuan; Li, Jing; Luu, Simon; LeBoff, Meryl S.; Glowacki, Julie; Zhou, Shuanhu
• Is Part Of: Journal of steroid biochemistry and molecular biology. Issue 199(2020)
• Publication Date: 2020-05
• Subjects: 1α 25OH2D -- 1α 25-dihydroxyvitamin D -- 25OHD 25-hydroxyvitamin D -- ALP alkaline phosphatase -- BMP-7 bone morphogenetic protein-7 -- CKD chronic kidney disease -- eGFR estimated glomerular filtration rate -- CYP27B1 cytochrome p450 27B1/25-hydroxyvitamin D 1α-hydroxylase -- FGFR1 fibroblast growth factor receptor 1 -- hMSCs human mesenchymal stem cells -- mKlotho membrane-bound Klotho -- rhFGF23 recombinant human fibroblast growth factor 23 -- sKlotho secreted Klotho; Vitamin D metabolism -- FGF23 -- Klotho/α Klotho -- CKD -- hMSCs -- BMP-7 -- Osteoblast differentiation; Steroid hormones -- Periodicals; Biochemistry -- Periodicals; Hormones -- Periodicals; Molecular Biology -- Periodicals; Hormones stéroïdes -- Périodiques; Steroid hormones; Periodicals; 572.579
• DOI: 10.1016/j.jsbmb.2020.105587
• Languages: English
• ISSNs: 0960-0760

Abstract

Highlights: Secreted and membrane-bound αKlotho gene expression in hMSCs were positively correlated with eGFR of the subjects from whom hMSCs were isolated. . There was a downregulated constitutive expression of αKlotho in hMSCs from hemodialysis subjects. In vitro, rhFGF23 altered vitamin D metabolism, which mimicked the ex vivo effects of CKD on hMSCs In vitro, rhFGF23 countered vitamin D-stimulated osteoblastogenesis and BMP-7 gene expression in hMSCs Abstract: Chronic kidney disease (CKD) is associated with elevated circulating fibroblast growth factor 23 (FGF23), impaired renal biosynthesis of 1α, 25-dihydroxyvitamin D (1α, 25(OH)2 D), low bone mass, and increased fracture risk. Our previous data with human mesenchymal stem cells (hMSCs) indicated that vitamin D metabolism in hMSCs is regulated as it is in the kidney and promotes osteoblastogenesis in an autocrine/paracrine manner. In this study, we tested the hypothesis that FGF23 inhibits vitamin D metabolism and action in hMSCs. hMSCs were isolated from discarded marrow during hip arthroplasty, including two subjects receiving hemodialysis and a series of 20 subjects (aged 49–83 years) with estimated glomerular filtration rate (eGFR) data. The direct in vitro effects of rhFGF23 on hMSCs were analyzed by RT-PCR, Western immunoblot, and biochemical assays. Ex vivo analyses showed positive correlations for both secreted and membrane-bound αKlotho gene expression in hMSCs with eGFR of the subjects from whom hMSCs were isolated. There was downregulated constitutive expression of αKlotho, but not FGFR1 in hMSCs obtained from two hemodialysis subjects. In vitro, rhFGF23 countered vitamin D-stimulated osteoblast differentiation of hMSCs by reducing the vitamin D receptor, CYP27B1/1α-hydroxylase, biosynthesis of 1α, 25(OH)2 D3, and signaling through BMP-7. These data demonstrate that dysregulated vitamin D metabolism in hMSCs may contribute to impaired osteoblastogenesis and altered bone and mineral metabolism in CKD subjects due to elevated FGF23. This supports the importance of intracellular vitamin D metabolism in autocrine/paracrine regulation of osteoblast differentiation in hMSCs.