title: Vitamin D metabolism and regulation in pediatric MSCs.
abstract: Vitamin D is crucial for mineral homeostasis and contributes to bone metabolism by inducing osteoblast differentiation of marrow stromal cells (MSCs). We recently reported that MSCs from adults demonstrate 1α-hydroxylase activity in vitro and express vitamin D-related genes; this raises a possible autocrine/paracrine role for D activation in pre-osteoblasts. In this studies, we tested the hypotheses that pediatric MSCs have 1α-hydroxylase activity and express vitamin D-related genes. With IRB approval, we isolated MSCs from discarded excess iliac marrow graft from 6 male and 6 female subjects (age 8-12 years) undergoing alveolar cleft repair. 1α-hydroxylation of substrate 25(OH)D3was measured by ELISA for 1α,25(OH)2D. RT-PCR was used for gene expression. Pediatric MSCs showed a range of 1α-hydroxylase activity in vitro. There was constitutive expression of vitamin D receptor (VDR), megalin, d-hydroxylases (CYP27B1, CYP27A1, CYP2R1, and CYP24A1), and estrogen receptor (ER). There was 2.6-fold greater expression of CYP27B1 and 3.5-fold greater expression of CYP24A1 in MSCs from boys compared with girls. There was 2.4-fold greater expression of ERα and 3.2-fold greater expression of megalin in MSCs from boys. In preliminary studies, treatment of female pediatric MSCs with 10nM 17β-estradiol resulted in upregulation of CYP27B1 and CYP24A1, as well as VDR, megalin, ERα, and ERβ. Treatment with 25(OH)D3upregulated CYP27B1, VDR, and ERα. Expression and regulation of vitamin D related genes in pediatric hMSCs reinforces an autocrine/paracrine role for vitamin D in hMSCs. Finding striking gender differences in MSCs from children was not seen with MSCs from adults and adds insight to the metabolic environment of bone and presents a research approach for investigating and optimizing pediatric bone health.
authors.affiliation: Department of Orthopedic Surgery, Brigham and Women's Hospital, Boston, MA, USA.
authors.forename: B
authors.initials: B
authors.lastname: Ruggiero
authors.affiliation: Department of Plastic and Oral Surgery, Boston Children's Hospital, Boston, MA, USA; Department of Oral and Maxillofacial Surgery, Harvard School of Dental Medicine, Boston, MA, USA.
authors.forename: B L
authors.initials: BL
authors.lastname: Padwa
authors.affiliation: Department of Orthopedic Surgery, Brigham and Women's Hospital, Boston, MA, USA.
authors.forename: K M
authors.initials: KM
authors.lastname: Christoph
authors.affiliation: Department of Orthopedic Surgery, Brigham and Women's Hospital, Boston, MA, USA; Department of Orthopedic Surgery, Harvard Medical School, Boston, MA, USA.
authors.forename: S
authors.initials: S
authors.lastname: Zhou
authors.affiliation: Department of Orthopedic Surgery, Brigham and Women's Hospital, Boston, MA, USA; Department of Oral and Maxillofacial Surgery, Harvard School of Dental Medicine, Boston, MA, USA; Department of Orthopedic Surgery, Harvard Medical School, Boston, MA, USA. Electronic address: jglowacki@bwh.harvard.edu.
authors.forename: J
authors.initials: J
authors.lastname: Glowacki
mesh_terms: D015090:25-Hydroxyvitamin D3 1-alpha-Hydroxylase / Q000235:genetics / Q000378:metabolism; D001854:Bone Marrow Cells / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D002112:Calcifediol / Q000378:metabolism* / Q000494:pharmacology; D002454:Cell Differentiation / Q000187:drug effects; D002648:Child; D053493:Cholestanetriol 26-Monooxygenase / Q000235:genetics / Q000378:metabolism; D000072467:Cytochrome P450 Family 2 / Q000235:genetics / Q000378:metabolism; D047628:Estrogen Receptor alpha / Q000235:genetics / Q000378:metabolism; D005260:Female; D005786:Gene Expression Regulation / Q000187:drug effects*; D006801:Humans; D026561:Low Density Lipoprotein Receptor-Related Protein-2 / Q000235:genetics / Q000378:metabolism; D008297:Male; D059630:Mesenchymal Stem Cells / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D010006:Osteoblasts / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D061251:Primary Cell Culture; D018167:Receptors, Calcitriol / Q000235:genetics / Q000378:metabolism; D012737:Sex Factors; D065668:Vitamin D3 24-Hydroxylase / Q000235:genetics / Q000378:metabolism
chemical_list: C506487:ESR1 protein, human; D047628:Estrogen Receptor alpha; D026561:Low Density Lipoprotein Receptor-Related Protein-2; D018167:Receptors, Calcitriol; C579457:VDR protein, human; D000072467:Cytochrome P450 Family 2; C506833:CYP2R1 protein, human; C506831:CYP27A1 protein, human; D053493:Cholestanetriol 26-Monooxygenase; C585549:CYP24A1 protein, human; D065668:Vitamin D3 24-Hydroxylase; D015090:25-Hydroxyvitamin D3 1-alpha-Hydroxylase; C000600378:CYP27B1 protein, human; D002112:Calcifediol
keywords: 1α-Hydroxylase; Children; Extra-renal; Marrow stromal cells; Vitamin D