1
|
Huang S, Li J, Hu X, Chen J. A Health Technology Assessment Based on Chinese Guideline: Active Vitamin D and Its Analogs in the Treatment of Osteoporosis. Drug Des Devel Ther 2024; 18:2593-2608. [PMID: 38947224 PMCID: PMC11214749 DOI: 10.2147/dddt.s465960] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2024] [Accepted: 06/18/2024] [Indexed: 07/02/2024] Open
Abstract
Objective To quantitatively assess all dosage forms of three active vitamin D and its analogs, namely, calcitriol, alfacalcidol, and eldecalcitol, to provide a basis for the selection of active vitamin D and its analogs in hospitals. Methods In this study, three active vitamin D and its analogs were evaluated by quantitative scoring in five dimensions, including pharmaceutical properties (28 points), efficacy (27 points), safety (25 points), economy (10 points), and other attributes (10 points). Results The final scores of quantitative assessment for the selection of alfacalcidol soft capsules, calcitriol soft capsules I, calcitriol soft capsules II, alfacalcidol tablets, alfacalcidol capsules, alfacalcidol oral drops, calcitriol injection, and eldecalcitol soft capsules were 73.17, 72.06, 71.52, 71.29, 69.62, 68.86, 65.60, 64.05 points. Conclusion Based on the scoring results, alfacalcidol soft capsules, calcitriol soft capsules I, calcitriol soft capsules II, alfacalcidol tablets can be entered into the medication list of medical institutions as strongly recommended drugs. This study offers guidance on selecting and using active vitamin D and its analogs in hospitals, with consideration for the patient's needs.
Collapse
Affiliation(s)
- Siyong Huang
- Key Specialty of Clinical Pharmacy, The First Affiliated Hospital of Guangdong Pharmaceutical University, Guangzhou, People’s Republic of China
| | - Jiabao Li
- Key Specialty of Clinical Pharmacy, The First Affiliated Hospital of Guangdong Pharmaceutical University, Guangzhou, People’s Republic of China
| | - Xiao Hu
- Key Specialty of Clinical Pharmacy, The First Affiliated Hospital of Guangdong Pharmaceutical University, Guangzhou, People’s Republic of China
| | - Jisheng Chen
- Key Specialty of Clinical Pharmacy, The First Affiliated Hospital of Guangdong Pharmaceutical University, Guangzhou, People’s Republic of China
| |
Collapse
|
2
|
Amarnath SS, Kumar V, Barik S. Vitamin D and Calcium and Bioavailability of Calcium in Various Calcium Salts. Indian J Orthop 2023; 57:62-69. [PMID: 38107810 PMCID: PMC10721582 DOI: 10.1007/s43465-023-01056-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/08/2023] [Accepted: 11/12/2023] [Indexed: 12/19/2023]
Abstract
Introduction The active form of vitamin D, 1,25D3, plays an important function in the metabolism of calcium. The recommended daily INTAKE of Calcium varies from 1300 mg/day during adolescence to 1200 mg/day after the age of 50 years. Similarly, for vitamin D, the recommended daily intake varies from 400 IU/day during adolescence to 1000 IU/day after the age of 70 years. There is an intricate inter-play of homeostasis of calcium led by vitamin D and PTH at various sites like intestine, kidney, and bones. The increased fracture risk due to bone loss and osteoporosis creates a burden on the patient, healthcare provider as well as the health system. As the population grows old worldwide gradually, the long-term sequelae like pain, loss of independence, and institutionalized care will become more pervasive. Behavioral change to incorporate a healthy lifestyle, including optimal calcium and vitamin D intake and physical exercise in adolescence, form the important foundation in the program for osteoporosis prevention. Conclusion Increased emphasis on lifestyle modification and nutrition should be given during times of increased bone loss in old age and after menopause.
Collapse
Affiliation(s)
- S. S. Amarnath
- Trauma and Orthopedic Surgeon, Trinity Central Hospital, Bangalore, India
| | - Vishal Kumar
- Department of Orthopedics, PGIMER, Chandigarh, India
| | - Sitanshu Barik
- Department of Orthopedics, All India Institute of Medical Sciences, Deoghar, India
| |
Collapse
|
3
|
Wu J, Fan Y, Zheng L, Wang Z, Liu Y, Shen C, Hu W. An Open-Label, Randomized Pharmacokinetic Study of 2 Formulations of Eldecalcitol Capsules Following Single Oral Administration in Healthy Chinese Volunteers Under Fasting and Fed Conditions. Clin Pharmacol Drug Dev 2022; 11:1322-1330. [PMID: 35988059 DOI: 10.1002/cpdd.1144] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2022] [Accepted: 06/28/2022] [Indexed: 01/27/2023]
Abstract
Eldecalcitol is an active vitamin D3 derivative that is used for the prevention and treatment of osteoporosis. The objectives of this study were to evaluate the bioequivalence and safety of 2 formulations of eldecalcitol capsule (0.75 μg) in healthy Chinese male and female volunteers, as well as to investigate the food effect on the pharmacokinetics of this drug. An open label, randomized, 3-period, 3-sequence, reference replicated crossover clinical study was performed in 27 healthy Chinese volunteers under fasting conditions, while a 2-way crossover study was carried out in 28 healthy Chinese volunteers under fed conditions. Volunteers were administered a single oral dose of 0.75 μg eldecalcitol after fasting overnight. Blood samples were collected at scheduled time points from 0 to 168 hours after administration of eldecalcitol. The 90%CIs of the test/reference geometric mean ratio (area under the plasma concentration-time curve and maximum plasma concentration) of eldecalcitol after a single-dose administration were within the acceptance criteria based on the average bioequivalence method. The time to maximum concentration of the test and reference formulations were elevated by ≈2.3-fold and 1.7-fold, respectively, after a high-fat meal. Only mild and transient adverse events were reported in this study, and no severe adverse events occurred. These results indicated that the 2 formulations of eldecalcitol were bioequivalent under both fasting and fed conditions. Food intake prolonged the oral absorption of eldecalcitol but did not significantly influence systemic exposure.
Collapse
Affiliation(s)
- Juan Wu
- Department of Clinical Pharmacology, The Second Hospital of Anhui Medical University, Hefei, China.,Anhui Provincial Institute of Translational Medicine, Hefei, China
| | - Yuru Fan
- Department of Clinical Pharmacology, The Second Hospital of Anhui Medical University, Hefei, China.,Anhui Provincial Institute of Translational Medicine, Hefei, China.,Inflammation and Immune Mediated Diseases Laboratory of Anhui Province, Anhui Institute of Innovative Drugs, School of Pharmacy, Anhui Medical University, Hefei, China
| | - Liang Zheng
- Department of Clinical Pharmacology, The Second Hospital of Anhui Medical University, Hefei, China.,Anhui Provincial Institute of Translational Medicine, Hefei, China
| | - Zhiqiang Wang
- Department of Clinical Pharmacology, The Second Hospital of Anhui Medical University, Hefei, China.,Anhui Provincial Institute of Translational Medicine, Hefei, China.,Menzies Institute for Medical Research, University of Tasmania, Hobart, Tasmania, Australia
| | - Yueyue Liu
- Department of Clinical Pharmacology, The Second Hospital of Anhui Medical University, Hefei, China.,Anhui Provincial Institute of Translational Medicine, Hefei, China
| | - Chenlin Shen
- Inflammation and Immune Mediated Diseases Laboratory of Anhui Province, Anhui Institute of Innovative Drugs, School of Pharmacy, Anhui Medical University, Hefei, China
| | - Wei Hu
- Department of Clinical Pharmacology, The Second Hospital of Anhui Medical University, Hefei, China.,Anhui Provincial Institute of Translational Medicine, Hefei, China
| |
Collapse
|
4
|
Salman A, Islam S, Saleh MA, Bhinder KK, Malik Z, Tahir I, Naveed MA. Nutritional and Biochemical Parameters Among Multiple Sclerosis Patients: A Case-Control Study. Cureus 2021; 13:e15108. [PMID: 34155466 PMCID: PMC8211432 DOI: 10.7759/cureus.15108] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Background The pathogenesis and prognosis of multiple sclerosis (MS) is an area of active medical research. Dietary and biochemical parameters such as serum 25-dihydroxycholecalciferol, magnesium, and potassium play a role in disease progression. This study aimed to compare the nutritional status and biochemical profile of patients with and without MS. Methodology This case-control study included a total of 112 participants (56 in the control group and 56 in the MS group). The participants’ socioeconomic and demographic profiles, nutritional status, and biochemical details were all gathered using history, patient files, and records. The effect of these parameters on the presence of MS was evaluated using a decision tree model. Student’s t-test and Mann-Whitney U test were performed to compare these parameters. Results A decision tree model was developed with an accuracy rate of 86.52%. The vitamin and mineral intake of the groups showed significant statistical differences (p = 0.001). The differences were important in terms of biochemical parameters, especially serum levels of 25-dihydroxycholecalciferol and potassium. Conclusions The key parameters that varied between MS patients and the control group, according to the constructed decision tree, were serum levels of 25-dihydroxycholecalciferol, magnesium, calcium, potassium, and carbohydrate intake. Nutritional measures against MS can be taken based on the decision tree.
Collapse
Affiliation(s)
- Asjad Salman
- Internal Medicine, Punjab Rangers Teaching Hospital, Lahore, PAK
| | - Sabeeh Islam
- Internal Medicine, St. Vincent Health Center, Buffalo, USA
| | - Muhammad Awais Saleh
- Internal Medicine, Government Khawaja Muhammad Safdar Medical College and Allied Institutions, Sialkot, PAK
| | | | - Zainab Malik
- Radiology, Shifa International Hospital Islamabad, Islamabad, PAK
| | - Iqra Tahir
- Internal Medicine, Lahore General Hospital, Lahore, PAK
| | - Muhammad A Naveed
- Cardiology, Allama Iqbal Memorial Teaching Hospital, Sialkot, PAK.,Cardiology, Government Khawaja Muhammad Safdar Medical College and Allied Institutions, Sialkot, PAK
| |
Collapse
|
5
|
Wu-Wong JR, Wessale JL, Chen YW, Chen T, Oubaidin M, Atsawasuwan P. A Novel Vitamin D Receptor Agonist, VS-105, Improves Bone Mineral Density without Affecting Serum Calcium in a Postmenopausal Osteoporosis Rat Model. JOURNAL OF EXPLORATORY RESEARCH IN PHARMACOLOGY 2020; 5:73-80. [PMID: 34589670 PMCID: PMC8478347 DOI: 10.14218/jerp.2020.00020] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
BACKGROUND AND OBJECTIVES VS-105, a novel vitamin D receptor agonist with significantly less hypercalcemic side effects than calcitriol, is a useful tool to investigate whether or not a vitamin D receptor agonist at non-hypercalcemic doses could improve bone mineral density (BMD). METHODS VS-105 and calcitriol were evaluated in an ovariectomized (OVX) osteoporosis rat model and in calvariae bone organ culture. RESULTS Treatment of OVX rats by VS-105 (0.1, 0.2 or 0.5 μg/kg, intraperitoneal, 3×/week, for 90 days) significantly improved BMD in the L3 lumbar vertebra in a dose-dependent manner (sham vs. OVX/vehicle: 324 ± 14 vs. 279 ± 10 mg/cm2; VS-105 at 0.1, 0.2 and 0.5 μg/kg: 306 ± 9, 329 ± 12, and 327 ± 10 mg/cm2, respectively) without affecting serum calcium (Ca). Calcitriol at 0.1 μg/kg significantly increased BMD but it also increased serum Ca. VS-105 and calcitriol at the test doses significantly suppressed serum parathyroid hormone and promoted tibia bone growth. With respect to biomarkers of bone remodeling, calcitriol and VS-105 both significantly elevated serum osteocalcin. In the calvariae bone organ culture, net Ca release was significantly less in VS-105-treated groups (vs. calcitriol). CONCLUSIONS VS-105 is efficacious in improving BMD in a dose range that does not affect serum Ca in OVX rats; the improvement in BMD by VS-105 is attributable to increased osteoblastic activity and reduced osteoclastic bone resorption.
Collapse
Affiliation(s)
- J. Ruth Wu-Wong
- Vidasym, Sioux Falls, SD, USA
- Correspondence to: J. Ruth Wu-Wong, Vidasym Inc., 2329 N Career Ave, #303, Sioux Falls, South Dakota, SD 57107 Tel: +1-847-863-9818; Fax: +1-847-260-8432.
| | | | | | | | - Maysaa Oubaidin
- Department of Orthodontics, University of Illinois, Chicago, IL, USA
| | | |
Collapse
|
6
|
Mori T, Horibe K, Koide M, Uehara S, Yamamoto Y, Kato S, Yasuda H, Takahashi N, Udagawa N, Nakamichi Y. The Vitamin D Receptor in Osteoblast-Lineage Cells Is Essential for the Proresorptive Activity of 1α,25(OH)2D3 In Vivo. Endocrinology 2020; 161:5912607. [PMID: 32987399 PMCID: PMC7575053 DOI: 10.1210/endocr/bqaa178] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/29/2020] [Accepted: 09/24/2020] [Indexed: 01/01/2023]
Abstract
We previously reported that daily administration of a pharmacological dose of eldecalcitol, an analog of 1α,25-dihydroxyvitamin D3 [1α,25(OH)2D3], increased bone mass by suppressing bone resorption. These antiresorptive effects were found to be mediated by the vitamin D receptor (VDR) in osteoblast-lineage cells. Using osteoblast-lineage-specific VDR conditional knockout (Ob-VDR-cKO) mice, we examined whether proresorptive activity induced by the high-dose 1α,25(OH)2D3 was also mediated by VDR in osteoblast-lineage cells. Administration of 1α,25(OH)2D3 (5 μg/kg body weight/day) to wild-type mice for 4 days increased the number of osteoclasts in bone and serum concentrations of C-terminal crosslinked telopeptide of type I collagen (CTX-I, a bone resorption marker). The stimulation of bone resorption was concomitant with the increase in serum calcium (Ca) and fibroblast growth factor 23 (FGF23) levels, and decrease in body weight. This suggests that a toxic dose of 1α,25(OH)2D3 can induce bone resorption and hypercalcemia. In contrast, pretreatment of wild-type mice with neutralizing anti-receptor activator of NF-κB ligand (RANKL) antibody inhibited the 1α,25(OH)2D3-induced increase of osteoclast numbers in bone, and increase of CTX-I, Ca, and FGF23 levels in serum. The pretreatment with anti-RANKL antibody also inhibited the 1α,25(OH)2D3-induced decrease in body weight. Consistent with observations in mice conditioned with anti-RANKL antibody, the high-dose administration of 1α,25(OH)2D3 to Ob-VDR-cKO mice failed to significantly increase bone osteoclast numbers, serum CTX-I, Ca, or FGF23 levels, and failed to reduce the body weight. Taken together, this study demonstrated that the proresorptive, hypercalcemic, and toxic actions of high-dose 1α,25(OH)2D3 are mediated by VDR in osteoblast-lineage cells.
Collapse
Affiliation(s)
- Tomoki Mori
- Graduate School of Oral Medicine, Matsumoto Dental University, Shiojiri, Nagano, Japan
| | - Kanji Horibe
- Department of Oral Histology, Matsumoto Dental University, Shiojiri, Nagano, Japan
| | - Masanori Koide
- Institute for Oral Science, Matsumoto Dental University, Shiojiri, Nagano, Japan
| | - Shunsuke Uehara
- Department of Biochemistry, Matsumoto Dental University, Shiojiri, Nagano, Japan
| | - Yoko Yamamoto
- Department of Surgical Oncology, The University of Tokyo, Tokyo, Japan
| | - Shigeaki Kato
- Research Institute of Innovative Medicine, Tokiwa Foundation, Iwaki, Fukushima, Japan
- Department of Basic Pathology, Fukushima Medical University, Fukushima, Japan
| | - Hisataka Yasuda
- Nagahama Institute for Biochemical Science, Oriental Yeast Co., Ltd., Nagahama, Shiga, Japan
| | - Naoyuki Takahashi
- Institute for Oral Science, Matsumoto Dental University, Shiojiri, Nagano, Japan
| | - Nobuyuki Udagawa
- Department of Biochemistry, Matsumoto Dental University, Shiojiri, Nagano, Japan
| | - Yuko Nakamichi
- Institute for Oral Science, Matsumoto Dental University, Shiojiri, Nagano, Japan
- Correspondence: Yuko Nakamichi, PhD, Institute for Oral Science, Matsumoto Dental University, 1780 Hiro-oka Gobara, Shiojiri, Nagano 399–0781, Japan. E-mail:
| |
Collapse
|
7
|
Zhao Q, Liu H, Jiang J, Wu Y, Zhong W, Li L, Miya K, Abe M, Hu P. Non-Compartmental Pharmacokinetics and Safety of Single-Dose Eldecalcitol (ED-71) in Healthy Chinese Adult Males. Clin Drug Investig 2018; 38:901-908. [PMID: 30117129 DOI: 10.1007/s40261-018-0682-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
BACKGROUND AND OBJECTIVES Eldecalcitol (ED-71) is a novel active vitamin D3 derivative, used for the treatment of osteoporosis. This is the first clinical study to investigate the pharmacokinetics and safety of eldecalcitol in Chinese subjects. METHODS This was an open, single-center, randomized, two-dose level, two-period crossover phase I study in 24 healthy Chinese adult males. Eligible subjects received a single oral dose of eldecalcitol capsule 0.5 or 0.75 μg at period 1 or period 2, monitored over a 144-h observation period for pharmacokinetics and a 14-day observation period for safety. The wash-out time was 14 days. The data observed in this study were compared with historical data in Japanese subjects to evaluate the inter-ethnic differences in pharmacokinetics. RESULTS After single doses of 0.5 and 0.75 μg eldecalcitol, the maximum serum concentration (Cmax) of eldecalcitol was reached within 3.0-4.0 h (Cmax was 0.0638 ± 0.0076 ng/ml in the 0.5-μg group and 0.0944 ± 0.0126 ng/ml in the 0.75-μg group, area under the concentration-time curve from 0 to 24 h (AUC(0-24h)) was 1.02 ± 0.15 ng·h/mL in the 0.5-μg group and 1.57 ± 0.26 ng·h/mL in the 0.75-μg group). The pharmacokinetic parameters was similar between the Chinese and Japanese subjects; both Cmax and partial AUCs could be considered to be dose-proportional over the tested dose range of 0.5-0.75 µg in Chinese subjects, which was in line with previously published results on eldecalcitol linear pharmacokinetics (range 0.1-1.0 µg) in Japanese subjects. Alanine aminotransferase increase was the most common adverse event (AE). No drug-related serious AEs were reported. All of the drug-related AEs of eldecalcitol were mild in severity. CONCLUSION Pharmacokinetic exposure (Cmax and partial AUCs) was dose-proportional over the tested dose range of 0.5-0.75 µg in healthy Chinese adult males. The pharmacokinetic character of eldecalcitol in Chinese subjects was similar to historical data from Japanese subjects. Eldecalcitol was well tolerated at doses ranging from 0.5 to 0.75 µg, with no new safety signals identified. CLINICAL TRIAL REGISTRATION This study was registered at the China Food and Drug Administration (Registration number: 2014L02212 and 2014L02213), and also registered at http://www.chinadrugtrials.org.cn (No. CTR20160430).
Collapse
Affiliation(s)
- Qian Zhao
- Clinical Pharmacology Research Center and Translational Medicine Centre, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, No. 41 Damucang, Xicheng District, Beijing, 100032, China.,Beijing Key Laboratory of Clinical PK and PD Investigation for Innovative Drugs, Beijing, 100032, China
| | - Hongzhong Liu
- Clinical Pharmacology Research Center and Translational Medicine Centre, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, No. 41 Damucang, Xicheng District, Beijing, 100032, China.,Beijing Key Laboratory of Clinical PK and PD Investigation for Innovative Drugs, Beijing, 100032, China
| | - Ji Jiang
- Clinical Pharmacology Research Center and Translational Medicine Centre, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, No. 41 Damucang, Xicheng District, Beijing, 100032, China.,Beijing Key Laboratory of Clinical PK and PD Investigation for Innovative Drugs, Beijing, 100032, China
| | - Yiwen Wu
- Clinical Pharmacology Research Center and Translational Medicine Centre, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, No. 41 Damucang, Xicheng District, Beijing, 100032, China.,Beijing Key Laboratory of Clinical PK and PD Investigation for Innovative Drugs, Beijing, 100032, China
| | - Wen Zhong
- Clinical Pharmacology Research Center and Translational Medicine Centre, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, No. 41 Damucang, Xicheng District, Beijing, 100032, China.,Beijing Key Laboratory of Clinical PK and PD Investigation for Innovative Drugs, Beijing, 100032, China
| | - Lili Li
- Clinical Pharmacology Research Center and Translational Medicine Centre, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, No. 41 Damucang, Xicheng District, Beijing, 100032, China.,Beijing Key Laboratory of Clinical PK and PD Investigation for Innovative Drugs, Beijing, 100032, China
| | - Kazuhiro Miya
- Translational Clinical Research Division, Clinical Pharmacology Department, Chugai Pharmaceutical Co., Ltd, Tokyo, Japan
| | - Masaichi Abe
- Translational Clinical Research Division, Clinical Pharmacology Department, Chugai Pharmaceutical Co., Ltd, Tokyo, Japan
| | - Pei Hu
- Clinical Pharmacology Research Center and Translational Medicine Centre, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, No. 41 Damucang, Xicheng District, Beijing, 100032, China. .,Beijing Key Laboratory of Clinical PK and PD Investigation for Innovative Drugs, Beijing, 100032, China.
| |
Collapse
|
8
|
Awasthi H, Mani D, Singh D, Gupta A. The underlying pathophysiology and therapeutic approaches for osteoporosis. Med Res Rev 2018; 38:2024-2057. [DOI: 10.1002/med.21504] [Citation(s) in RCA: 41] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2017] [Revised: 02/28/2018] [Accepted: 04/04/2018] [Indexed: 12/11/2022]
Affiliation(s)
- Harshika Awasthi
- Herbal Medicinal Products Department; CSIR-Central Institute of Medicinal and Aromatic Plants; Lucknow India
| | - Dayanandan Mani
- Herbal Medicinal Products Department; CSIR-Central Institute of Medicinal and Aromatic Plants; Lucknow India
| | - Divya Singh
- Division of Endocrinology; CSIR-Central Drug Research Institute; Lucknow India
| | - Atul Gupta
- Medicinal Chemistry Department; CSIR-Central Institute of Medicinal and Aromatic Plants; Lucknow India
| |
Collapse
|
9
|
Nakamichi Y, Udagawa N, Suda T, Takahashi N. Mechanisms involved in bone resorption regulated by vitamin D. J Steroid Biochem Mol Biol 2018; 177:70-76. [PMID: 29146302 DOI: 10.1016/j.jsbmb.2017.11.005] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/26/2017] [Revised: 10/26/2017] [Accepted: 11/12/2017] [Indexed: 12/31/2022]
Abstract
Active forms of vitamin D enhance osteoclastogenesis in vitro and in vivo through the vitamin D receptor (VDR) in osteoblast-lineage cells consisting of osteoblasts and osteocytes. This pro-resorptive activity was evident basically with higher concentrations of active vitamin D than those expected in physiological conditions. Nevertheless, vitamin D compounds have been used in Japan for treating osteoporosis to increase bone mineral density (BMD). Of note, the increase in BMD by long-term treatment with pharmacological (=near-physiological) doses of vitamin D compounds was caused by the suppression of bone resorption. Therefore, whether vitamin D expresses pro-resorptive or anti-resorptive properties seems to be dependent on the treatment protocols. We established osteoblast lineage-specific and osteoclast-specific VDR conditional knockout (cKO) mice using Osterix-Cre transgenic mice and Cathepsin K-Cre knock-in mice, respectively. According to our observation using these cKO mouse lines, neither VDR in osteoblast-lineage cells nor that in osteoclasts played important roles for osteoclastogenesis and bone resorption at homeostasis. However, using our cKO lines, we observed that VDR in osteoblast-lineage cells, but not osteoclasts, was involved in the anti-resorptive properties of pharmacological doses of vitamin D compounds in vivo. Two different osteoblast-lineage VDR cKO mouse lines were reported. One is a VDR cKO mouse line using alpha 1, type I collagen (Col1a1)-Cre transgenic mice (here we call Col1a1-VDR-cKO mice) and the other is that using dentin matrix protein 1 (Dmp1)-Cre transgenic mice (Dmp1-VDR-cKO mice). Col1a1-VDR-cKO mice exhibited slightly increased bone mass due to lowered bone resorption. In contrast, Dmp1-VDR-cKO mice exhibited no difference in BMD in agreement with our results regarding Ob-VDR-cKO mice. Here we discuss contradictory results and multiple modes of actions of vitamin D in bone resorption in detail. (279 words).
Collapse
Affiliation(s)
- Yuko Nakamichi
- Institute for Oral Science, Matsumoto Dental University, Shiojiri, Nagano 399-0781, Japan.
| | - Nobuyuki Udagawa
- Department of Biochemistry, Matsumoto Dental University, Shiojiri, Nagano 399-0781, Japan
| | - Tatsuo Suda
- Research Center for Genomic Medicine, Saitama Medical University, Saitama 350-1241, Japan
| | - Naoyuki Takahashi
- Institute for Oral Science, Matsumoto Dental University, Shiojiri, Nagano 399-0781, Japan
| |
Collapse
|
10
|
Li A, Cong Q, Xia X, Leong WF, Yeh J, Miao D, Mishina Y, Liu H, Li B. Pharmacologic Calcitriol Inhibits Osteoclast Lineage Commitment via the BMP-Smad1 and IκB-NF-κB Pathways. J Bone Miner Res 2017; 32:1406-1420. [PMID: 28370465 PMCID: PMC5814246 DOI: 10.1002/jbmr.3146] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/22/2017] [Revised: 03/23/2017] [Accepted: 03/28/2017] [Indexed: 12/26/2022]
Abstract
Vitamin D is involved in a range of physiological processes and its active form and analogs have been used to treat diseases such as osteoporosis. Yet how vitamin D executes its function remains unsolved. Here we show that the active form of vitamin D calcitriol increases the peak bone mass in mice by inhibiting osteoclastogenesis and bone resorption. Although calcitriol modestly promoted osteoclast maturation, it strongly inhibited osteoclast lineage commitment from its progenitor monocyte by increasing Smad1 transcription via the vitamin D receptor and enhancing BMP-Smad1 activation, which in turn led to increased IκBα expression and decreased NF-κB activation and NFATc1 expression, with IκBα being a Smad1 target gene. Inhibition of BMP type I receptor or ablation of Bmpr1a in monocytes alleviated the inhibitory effects of calcitriol on osteoclast commitment, bone resorption, and bone mass augmentation. These findings uncover crosstalk between the BMP-Smad1 and RANKL-NF-κB pathways during osteoclastogenesis that underlies the action of active vitamin D on bone health. © 2017 American Society for Bone and Mineral Research.
Collapse
Affiliation(s)
- Anna Li
- Bio-X-Renji Hospital Research Center, Renji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China.,Key Laboratory of Birth Regulation and Control Technology of National Health and Family Planning Commission of China, Maternal and Child Health Care Hospital of Shandong Province, Shandong, China.,Department of Histology and Embryology, Shandong University School of Medicine, Shandong, China
| | - Qian Cong
- The Bio-X Institutes, Key Laboratory for the Genetics of Developmental and Neuropsychiatric Disorders, Ministry of Education, Shanghai Jiao Tong University, Shanghai, China
| | - Xuechun Xia
- The Bio-X Institutes, Key Laboratory for the Genetics of Developmental and Neuropsychiatric Disorders, Ministry of Education, Shanghai Jiao Tong University, Shanghai, China
| | - Wai Fook Leong
- Institute of Molecular and Cell Biology, Agency for Science, Technology and Research (A*STAR), Singapore
| | - James Yeh
- The Bio-X Institutes, Key Laboratory for the Genetics of Developmental and Neuropsychiatric Disorders, Ministry of Education, Shanghai Jiao Tong University, Shanghai, China
| | - Dengshun Miao
- State Key Laboratory of Reproductive Medicine, The Research Center for Bone and Stem Cells, Department of Anatomy, Histology and Embryology, Nanjing Medical University, Nanjing, China
| | - Yuji Mishina
- Department of Biologic and Materials Sciences, School of Dentistry, University of Michigan, Ann Arbor, MI, USA
| | - Huijuan Liu
- Bio-X-Renji Hospital Research Center, Renji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - Baojie Li
- Bio-X-Renji Hospital Research Center, Renji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China.,The Bio-X Institutes, Key Laboratory for the Genetics of Developmental and Neuropsychiatric Disorders, Ministry of Education, Shanghai Jiao Tong University, Shanghai, China
| |
Collapse
|
11
|
Nakamichi Y, Udagawa N, Horibe K, Mizoguchi T, Yamamoto Y, Nakamura T, Hosoya A, Kato S, Suda T, Takahashi N. VDR in Osteoblast-Lineage Cells Primarily Mediates Vitamin D Treatment-Induced Increase in Bone Mass by Suppressing Bone Resorption. J Bone Miner Res 2017; 32:1297-1308. [PMID: 28177161 DOI: 10.1002/jbmr.3096] [Citation(s) in RCA: 49] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/30/2016] [Revised: 02/01/2017] [Accepted: 02/03/2017] [Indexed: 01/01/2023]
Abstract
Long-term treatment with active vitamin D [1α,25(OH)2 D3 ] and its derivatives is effective for increasing bone mass in patients with primary and secondary osteoporosis. Derivatives of 1α,25(OH)2 D3 , including eldecalcitol (ELD), exert their actions through the vitamin D receptor (VDR). ELD is more resistant to metabolic degradation than 1α,25(OH)2 D3 . It is reported that ELD treatment causes a net increase in bone mass by suppressing bone resorption rather than by increasing bone formation in animals and humans. VDR in bone and extraskeletal tissues regulates bone mass and secretion of osteotropic hormones. Therefore, it is unclear what types of cells expressing VDR preferentially regulate the vitamin D-induced increase in bone mass. Here, we examined the effects of 4-week treatment with ELD (50 ng/kg/day) on bone using osteoblast lineage-specific VDR conditional knockout (Ob-VDR-cKO) and osteoclast-specific VDR cKO (Ocl-VDR-cKO) male mice aged 10 weeks. Immunohistochemically, VDR in bone was detected preferentially in osteoblasts and osteocytes. Ob-VDR-cKO mice showed normal bone phenotypes, despite no appreciable immunostaining of VDR in bone. Ob-VDR-cKO mice failed to increase bone mass in response to ELD treatment. Ocl-VDR-cKO mice also exhibited normal bone phenotypes, but normally responded to ELD. ELD-induced FGF23 production in bone was regulated by VDR in osteoblast-lineage cells. These findings suggest that the vitamin D treatment-induced increase in bone mass is mediated by suppressing bone resorption through VDR in osteoblast-lineage cells. © 2017 The Authors. Journal of Bone and Mineral Research Published by Wiley Periodicals Inc.
Collapse
Affiliation(s)
- Yuko Nakamichi
- Institute for Oral Science, Matsumoto Dental University, Nagano, Japan
| | - Nobuyuki Udagawa
- Department of Biochemistry, Matsumoto Dental University, Nagano, Japan
| | - Kanji Horibe
- Department of Oral Histology, Matsumoto Dental University, Nagano, Japan
| | | | - Yoko Yamamoto
- Department of Surgical Oncology, The University of Tokyo, Tokyo, Japan
| | - Takashi Nakamura
- Department of Biochemistry & Integrative Medical Biology, School of Medicine, Keio University, Tokyo, Japan
| | - Akihiro Hosoya
- Department of Oral Histology, Matsumoto Dental University, Nagano, Japan
| | - Shigeaki Kato
- Jyoban Hospital, Tokiwa Foundation, Fukushima, Japan
| | - Tatsuo Suda
- Research Center for Genomic Medicine, Saitama Medical University, Saitama, Japan
| | - Naoyuki Takahashi
- Institute for Oral Science, Matsumoto Dental University, Nagano, Japan
| |
Collapse
|
12
|
Zhang L, Chen X, Wu J, Yuan Y, Guo J, Biswas S, Li B, Zou J. The effects of different intensities of exercise and active vitamin D on mouse bone mass and bone strength. J Bone Miner Metab 2017; 35:265-277. [PMID: 27357401 DOI: 10.1007/s00774-016-0764-9] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/17/2015] [Accepted: 05/05/2016] [Indexed: 02/07/2023]
Abstract
Physical exercise is beneficial to bone health. However, little is known how different intensities of exercise affect bone mass and strength. In the present study, we used young mice to study the effects of different intensities of exercise on bone mass and bone strength in comparison to pharmacological doses of active vitamin D (calcitriol). We found that only the medium level of exercise tested showed a positive effect on bone mineral density, trabecular bone volume, and bone strength, which are attributable to a decrease in bone resorption and an increase in bone formation, with the latter being accompanied by an increase in the number of osteogenic mesenchymal stem cells in the bone marrow. Calcitriol increases bone volume and bone strength, yet the combination of calcitriol and medium-intensity exercise did not further improve bone mass or strength. Moreover, calcitriol also showed some protective effect on the bone in mice with high levels of exercise. These results indicate that exercise at medium intensity increases bone mass and strength via affecting both bone formation and resorption and that its beneficial effects on bone mass cannot be further improved by calcitriol.
Collapse
Affiliation(s)
- Lingli Zhang
- School of Kinesiology, Shanghai University of Sport, Shanghai, 200438, China
| | - Xi Chen
- School of Sports Science, Wenzhou Medical University, Wenzhou, 325035, China
- School of Kinesiology, Shanghai University of Sport, Shanghai, 200438, China
| | - Juanni Wu
- School of Kinesiology, Shanghai University of Sport, Shanghai, 200438, China
| | - Yu Yuan
- School of Kinesiology, Shanghai University of Sport, Shanghai, 200438, China
| | - Jianmin Guo
- School of Kinesiology, Shanghai University of Sport, Shanghai, 200438, China
| | - Soma Biswas
- Key Laboratory for the Genetics of Developmental and Neuropsychiatric Disorders, Bio-X Institutes, Ministry of Education, Shanghai Jiao Tong University, Shanghai, 200240, China
- School of Pharmacy, Shanghai Jiao Tong University, Shanghai, 200240, China
| | - Baojie Li
- Key Laboratory for the Genetics of Developmental and Neuropsychiatric Disorders, Bio-X Institutes, Ministry of Education, Shanghai Jiao Tong University, Shanghai, 200240, China
| | - Jun Zou
- Scientific Research Department, Shanghai University of Sport, 399 Changhai Road, Yangpu District, Shanghai, 200438, China.
| |
Collapse
|
13
|
Role of Vitamin D in Uremic Vascular Calcification. BIOMED RESEARCH INTERNATIONAL 2017; 2017:2803579. [PMID: 28286758 PMCID: PMC5329659 DOI: 10.1155/2017/2803579] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/01/2016] [Revised: 12/26/2016] [Accepted: 01/16/2017] [Indexed: 12/16/2022]
Abstract
The risk of cardiovascular death is 10 times higher in patients with CKD (chronic kidney disease) than in those without CKD. Vascular calcification, common in patients with CKD, is a predictor of cardiovascular mortality. Vitamin D deficiency, another complication of CKD, is associated with vascular calcification in patients with CKD. GFR decline, proteinuria, tubulointerstitial injury, and the therapeutic dose of active form vitamin D aggravate vitamin D deficiency and reduce its pleiotropic effect on the cardiovascular system. Vitamin D supplement for CKD patients provides a protective role in vascular calcification on the endothelium by (1) renin-angiotensin-aldosterone system inactivation, (2) alleviating insulin resistance, (3) reduction of cholesterol and inhibition of foam cell and cholesterol efflux in macrophages, and (4) modulating vascular regeneration. For the arterial calcification, vitamin D supplement provides adjunctive role in regressing proteinuria, reverse renal osteodystrophy, and restoring calcification inhibitors. Recently, adventitial progenitor cell has been linked to be involved in the vascular calcification. Vitamin D may provide a role in modulating adventitial progenitor cells. In summary, vitamin D supplement may provide an ancillary role for ameliorating uremic vascular calcification.
Collapse
|
14
|
Vitamin D, calcium homeostasis and aging. Bone Res 2016; 4:16041. [PMID: 27790378 PMCID: PMC5068478 DOI: 10.1038/boneres.2016.41] [Citation(s) in RCA: 198] [Impact Index Per Article: 24.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2016] [Revised: 08/31/2016] [Accepted: 09/04/2016] [Indexed: 12/15/2022] Open
Abstract
Osteoporosis is characterized by low bone mass and microarchitecture deterioration of bone tissue, leading to enhanced bone fragility and consequent increase in fracture risk. Evidence is accumulating for an important role of calcium deficiency as the process of aging is associated with disturbed calcium balance. Vitamin D is the principal factor that maintains calcium homeostasis. Increasing evidence indicates that the reason for disturbed calcium balance with age is inadequate vitamin D levels in the elderly. In this article, an overview of our current understanding of vitamin D, its metabolism, and mechanisms involved in vitamin D-mediated maintenance of calcium homeostasis is presented. In addition, mechanisms involved in age-related dysregulation of 1,25(OH)2D3 action, recommended daily doses of vitamin D and calcium, and the use of vitamin D analogs for the treatment of osteoporosis (which remains controversial) are reviewed. Elucidation of the molecular pathways of vitamin D action and modifications that occur with aging will be an active area of future research that has the potential to reveal new therapeutic strategies to maintain calcium balance.
Collapse
|
15
|
Yang I, Choi H, Nam SJ, Kang H. A new 9,11-secosterol with a 1,4-quinone from a Korean marine sponge Ircinia sp. Arch Pharm Res 2015; 38:1970-4. [DOI: 10.1007/s12272-015-0620-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2015] [Accepted: 05/26/2015] [Indexed: 11/29/2022]
|
16
|
Saito M, Grynpas MD, Burr DB, Allen MR, Smith SY, Doyle N, Amizuka N, Hasegawa T, Kida Y, Marumo K, Saito H. Treatment with eldecalcitol positively affects mineralization, microdamage, and collagen crosslinks in primate bone. Bone 2015; 73:8-15. [PMID: 25482210 DOI: 10.1016/j.bone.2014.11.025] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/30/2014] [Revised: 11/17/2014] [Accepted: 11/29/2014] [Indexed: 01/22/2023]
Abstract
Eldecalcitol (ELD), an active form of vitamin D analog approved for the treatment of osteoporosis in Japan, increases lumbar spine bone mineral density (BMD), suppresses bone turnover markers, and reduces fracture risk in patients with osteoporosis. We have previously reported that treatment with ELD for 6 months improved the mechanical properties of the lumbar spine in ovariectomized (OVX) cynomolgus monkeys. ELD treatment increased lumbar BMD, suppressed bone turnover markers, and reduced histomorphometric parameters of both bone formation and resorption in vertebral trabecular bone. In this study, we elucidated the effects of ELD on bone quality (namely, mineralization, microarchitecture, microdamage, and bone collagen crosslinks) in OVX cynomolgus monkeys in comparison with OVX-vehicle control monkeys. Density fractionation of bone powder prepared from lumbar vertebrae revealed that ELD treatment shifted the distribution profile of bone mineralization to a higher density, and backscattered electron microscopic imaging showed improved trabecular bone connectivity in the ELD-treated groups. Higher doses of ELD more significantly reduced the amount of microdamage compared to OVX-vehicle controls. The fractionated bone powder samples were divided according to their density, and analyzed for collagen crosslinks. Enzymatic crosslinks were higher in both the high-density (≥2.0 mg/mL) and low-density (<2.0 mg/mL) fractions from the ELD-treated groups than in the corresponding fractions in the OVX-vehicle control groups. On the other hand, non-enzymatic crosslinks were lower in both the high- and low-density fractions. These observations indicated that ELD treatment stimulated the enzymatic reaction of collagen crosslinks and bone mineralization, but prevented non-enzymatic reaction of collagen crosslinks and accumulation of bone microdamage. Bone anti-resorptive agents such as bisphosphonates slow down bone remodeling so that bone mineralization, bone microdamage, and non-enzymatic collagen crosslinks all increase. Bone anabolic agents such as parathyroid hormone decrease bone mineralization and bone microdamage by stimulating bone remodeling. ELD did not fit into either category. Histological analysis indicated that the ELD treatment strongly suppressed bone resorption by reducing the number of osteoclasts, while also stimulating focal bone formation without prior bone resorption (bone minimodeling). These bidirectional activities of ELD may account for its unique effects on bone quality.
Collapse
Affiliation(s)
- Mitsuru Saito
- Jikei University School of Medicine, Orthopedic Surgery Department, 3-25-8 Nishishinbashi, Minato-ku, Tokyo 105-8461, Japan.
| | - Marc D Grynpas
- Samuel Lunenfeld Research Institute, Mount Sinai Hospital, Toronto, Canada
| | - David B Burr
- Department of Anatomy and Cell Biology, Department of Orthopaedic Surgery, Indiana University School of Medicine, Indianapolis, USA
| | - Matthew R Allen
- Department of Anatomy and Cell Biology, Department of Orthopaedic Surgery, Indiana University School of Medicine, Indianapolis, USA
| | - Susan Y Smith
- Musculoskeletal Research, Charles River Laboratories Preclinical Services Montreal, Senneville, Quebec, Canada
| | - Nancy Doyle
- Musculoskeletal Research, Charles River Laboratories Preclinical Services Montreal, Senneville, Quebec, Canada
| | - Norio Amizuka
- Division of Oral Health Science, Graduate School of Dental Medicine, Hokkaido University, Sapporo, Japan
| | - Tomoka Hasegawa
- Division of Oral Health Science, Graduate School of Dental Medicine, Hokkaido University, Sapporo, Japan
| | - Yoshikuni Kida
- Jikei University School of Medicine, Orthopedic Surgery Department, 3-25-8 Nishishinbashi, Minato-ku, Tokyo 105-8461, Japan
| | - Keishi Marumo
- Jikei University School of Medicine, Orthopedic Surgery Department, 3-25-8 Nishishinbashi, Minato-ku, Tokyo 105-8461, Japan
| | - Hitoshi Saito
- Medical Science Department, Chugai Pharmaceutical Co., Ltd., Tokyo, Japan
| |
Collapse
|
17
|
Sugiyama T, Kim YT, Oda H. Osteoporosis therapy: a novel insight from natural homeostatic system in the skeleton. Osteoporos Int 2015; 26:443-7. [PMID: 25288445 DOI: 10.1007/s00198-014-2923-y] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/08/2014] [Accepted: 09/25/2014] [Indexed: 01/22/2023]
Abstract
The skeleton normally responds to mechanical environment to maintain the resulting elastic deformation (strain) of bone, while increased bone strength by an osteoporosis drug results in decreased bone strain. Thus, it can be hypothesized that the effect of osteoporosis therapy is limited by natural homeostatic system in the skeleton. This logic is consistent with the fact that there exists a powerful effect that returns bone mass to its pre-treatment level after the withdrawal of treatment with osteoporosis agents. The present hypothesis provides a new significant insight into the mechanisms by which osteoporosis drugs improve bone fragility. Here we briefly discuss the effects of teriparatide, romosozumab, and odanacatib on bones in animals and humans.
Collapse
Affiliation(s)
- T Sugiyama
- Department of Orthopaedic Surgery, Saitama Medical University, 38 Morohongo, Moroyama, Saitama, 350-0495, Japan,
| | | | | |
Collapse
|
18
|
Eisman JA, Bouillon R. Vitamin D: direct effects of vitamin D metabolites on bone: lessons from genetically modified mice. BONEKEY REPORTS 2014; 3:499. [PMID: 24605216 PMCID: PMC3944130 DOI: 10.1038/bonekey.2013.233] [Citation(s) in RCA: 54] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/23/2013] [Accepted: 11/26/2013] [Indexed: 12/14/2022]
Abstract
The vitamin D endocrine system has clear beneficial effects on bone as demonstrated by prevention of rickets in children and by reducing the risk of osteomalacia or osteoporosis in adults or elderly subjects. Depending on the design of the study of genetically modified animals, however, 1,25(OH)2D and the vitamin D receptor (VDR) may have no effect, beneficial or even deleterious direct effects on bone. We present here a comprehensive model of the direct effects of vitamin D on bone. In case of sufficient calcium supply, vitamin D and its metabolites can improve the calcium balance and facilitate mineral deposition in bone matrix largely without direct effects on bone cells, although some beneficial effects may occur via mature osteoblasts, as demonstrated in mice with osteoblast-specific overexpression of VDR or 1α-hydroxylase. In case of calcium deficiency, however, 1,25(OH)2D enhances bone resorption, whereas simultaneously inhibiting bone mineralization, so as to defend serum calcium homeostasis at the expense of bone mass. This dual role probably provides a survival benefit for land vertebrates living in a calcium-poor environment.
Collapse
Affiliation(s)
- John A Eisman
- Clinical Excellence and Research, School of Medicine Sydney, UNDA, Sydney, NSW, Australia
- Clinical Translation and Advanced Education, Garvan Institute of Medical Research, Darlinghurst, NSW, Australia
- St Vincent's Hospital, Sydney, NSW, Australia
- University of New South Wales, Randwick, NSW, Australia
- CAPHRI - School for Public Health and Primary Care, Maastricht, The Netherlands
| | - Roger Bouillon
- Clinical and Experimental Medicine, KU Leuven, Leuven, Belgium
- Department of Endocrinology, University Hospitals Leuven, Leuven, Belgium
| |
Collapse
|