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Stawicki MK, Abramowicz P, Sokolowska G, Wołejszo S, Grant WB, Konstantynowicz J. Can vitamin D be an adjuvant therapy for juvenile rheumatic diseases? Rheumatol Int 2023; 43:1993-2009. [PMID: 37566255 PMCID: PMC10495493 DOI: 10.1007/s00296-023-05411-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2023] [Accepted: 07/27/2023] [Indexed: 08/12/2023]
Abstract
Vitamin D, known for its essential role in calcium and bone homeostasis, has multiple effects beyond the skeleton, including regulation of immunity and modulation of autoimmune processes. Several reports have shown suboptimal serum 25 hydroxyvitamin D [25(OH)D] levels in people with different inflammatory and autoimmune rheumatic conditions, and an association between 25(OH)D levels, disease activity and outcomes. Although most available data pertain to adults, insights often are extended to children. Juvenile rheumatic diseases (JRDs) are a significant health problem during growth because of their complex pathogenesis, chronic nature, multisystemic involvement, and long-term consequences. So far, there is no definitive or clear evidence to confirm the preventive or therapeutic effect of vitamin D supplementation in JRDs, because results from randomized controlled trials (RCTs) have produced inconsistent outcomes. This review aims to explore and discuss the potential role of vitamin D in treating selected JRDs. Medline/PubMed, EMBASE, and Scopus were comprehensively searched in June 2023 for any study on vitamin D supplementary role in treating the most common JRDs. We used the following keywords: "vitamin D" combined with the terms "juvenile idiopathic arthritis", "juvenile systemic scleroderma", "juvenile systemic lupus erythematosus", "juvenile inflammatory myopathies", "Behcet disease", "periodic fever syndromes" and "juvenile rheumatic diseases". Observational studies have found that serum 25(OH)D concentrations are lower in juvenile idiopathic arthritis, juvenile systemic lupus erythematosus, juvenile systemic scleroderma, Behcet disease and proinflammatory cytokine concentrations are higher. This suggests that vitamin D supplementation might be beneficial, however, current data are insufficient to confirm definitively the complementary role of vitamin D in the treatment of JRDs. Considering the high prevalence of vitamin D deficiency worldwide, children and adolescents should be encouraged to supplement vitamin D according to current recommendations. More interventional studies, especially well-designed RCTs, assessing the dose-response effect and adjuvant effect in specific diseases, are needed to determine the potential significance of vitamin D in JRDs treatment.
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Affiliation(s)
- Maciej K. Stawicki
- Department of Pediatrics, Rheumatology, Immunology, and Metabolic Bone Diseases, Medical University of Bialystok, University Children’s Clinical Hospital in Bialystok, Waszyngtona Street 17, 15274 Bialystok, Poland
| | - Paweł Abramowicz
- Department of Pediatrics, Rheumatology, Immunology, and Metabolic Bone Diseases, Medical University of Bialystok, University Children’s Clinical Hospital in Bialystok, Waszyngtona Street 17, 15274 Bialystok, Poland
| | | | - Sebastian Wołejszo
- Department of Pediatrics, Rheumatology, Immunology, and Metabolic Bone Diseases, Medical University of Bialystok, University Children’s Clinical Hospital in Bialystok, Waszyngtona Street 17, 15274 Bialystok, Poland
| | - William B. Grant
- Sunlight, Nutrition, and Health Research Center, San Francisco, CA USA
| | - Jerzy Konstantynowicz
- Department of Pediatrics, Rheumatology, Immunology, and Metabolic Bone Diseases, Medical University of Bialystok, University Children’s Clinical Hospital in Bialystok, Waszyngtona Street 17, 15274 Bialystok, Poland
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Affiliation(s)
- Cheryl P. Sanchez
- Pediatrics University of Wisconsin Medical School Madison, Wisconsin, USA
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Pan Q, O'Connor MI, Coutts RD, Hyzy SL, Olivares-Navarrete R, Schwartz Z, Boyan BD. Characterization of osteoarthritic human knees indicates potential sex differences. Biol Sex Differ 2016; 7:27. [PMID: 27257472 PMCID: PMC4890516 DOI: 10.1186/s13293-016-0080-z] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/17/2016] [Accepted: 05/12/2016] [Indexed: 01/10/2023] Open
Abstract
BACKGROUND The prevalence of osteoarthritis is higher in women than in men in every age group, and overall prevalence increases with advancing age. Sex-specific differences in the properties of osteoarthritic joint tissues may permit the development of sex-specific therapies. Sex hormones regulate cartilage and bone development and homeostasis in a sex-dependent manner. Recent in vitro studies show that the vitamin D3 metabolite 1α,25-dihydroxyvitamin D3 [1α,25(OH)2D3] also has sex-specific effects on musculoskeletal cells, suggesting that vitamin D3 metabolites may play a role in osteoarthritis-related sex-specific differences. The purpose of this study was to determine if sex-specific differences exist in synovial fluid and knee tissues isolated from male and female patients with severe knee osteoarthritis. We determined the presence of vitamin D3 metabolites, inflammatory cytokines, growth factors, and matrix metalloproteinases (MMPs) in synovial fluid and assessed responses of articular chondrocytes and subchondral osteoblasts to 17β-estradiol, dihydrotestosterone, and 1α,25(OH)2D3. METHODS Samples from knee joints of 10 Caucasian male and 10 Caucasian female patients with advanced osteoarthritis aged 65 to 75 years were obtained from total knee arthroplasty. Vitamin D metabolites, cytokines, MMPs, and growth factors in the synovial fluid were measured. Primary cultures of chondrocytes were isolated from fibrillated articular cartilage adjacent to osteoarthritis lesions and minimally affected cartilage distal to the lesion. Osteoblasts were isolated from the subchondral bone. Expression of receptors for 17β-estradiol and 1α,25(OH)2D3 was assessed by real-time PCR. Chondrocytes and osteoblasts were treated with 10(-8) M 17β-estradiol, dihydrotestosterone, or 1α,25(OH)2D3 and effects on gene expression and protein synthesis determined. RESULTS Histology of the articular cartilage confirmed advanced osteoarthritis. Sex differences were found in synovial fluid levels of vitamin D metabolites, cytokines, and metalloproteinases as well as in the cellular expression of receptors for 17β-estradiol and 1α,25(OH)2D3. Male cells were more responsive to 1α,25(OH)2D3 and dihydrotestosterone, whereas 17β-estradiol-affected female cells. CONCLUSIONS These results demonstrate that there are underlying sex differences in knee tissues affected by osteoarthritis. Our findings do not address osteoarthritis etiology but have implications for different prevention methods and treatments for men and women. Further research is needed to better understand these sex-based differences.
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Affiliation(s)
- Qingfen Pan
- Department of Mechanical Engineering, Georgia Institute of Technology, Atlanta, GA USA
| | - Mary I O'Connor
- Center for Musculoskeletal Care, Yale University School of Medicine, New Haven, CT USA
| | - Richard D Coutts
- Department of Orthopaedics, University of California at San Diego, San Diego, CA USA
| | - Sharon L Hyzy
- Department of Biomedical Engineering, Virginia Commonwealth University, Richmond, VA USA
| | | | - Zvi Schwartz
- Department of Biomedical Engineering, Virginia Commonwealth University, Richmond, VA USA ; Department of Periodontics, University of Texas Health Science Center at San Antonio, San Antonio, TX USA
| | - Barbara D Boyan
- Department of Biomedical Engineering, Virginia Commonwealth University, Richmond, VA USA ; Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology, Atlanta, GA USA ; School of Engineering, Virginia Commonwealth University, 601 West Main Street, Suite 331, Richmond, VA 23284 USA
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Sanghi D, Mishra A, Sharma AC, Raj S, Mishra R, Kumari R, Natu SM, Agarwal S, Srivastava RN. Elucidation of dietary risk factors in osteoarthritis knee—a case-control study. J Am Coll Nutr 2014; 34:15-20. [PMID: 25387081 DOI: 10.1080/07315724.2013.875439] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
BACKGROUND AND OBJECTIVE Nutritional imbalance, combined with endocrine abnormalities, may be involved in the pathogenesis of osteoarthritis (OA). This study was conducted to determine the association of OA with dietary factors, such as quantity and quality of nutrient intake. METHODS This case-control study enrolled 180 knee osteoarthritis (KOA) subjects who met the American College of Rheumatology definition of KOA, with an equal number of matched controls. Outcome measures, such as dietary nutrient intake and its frequency, were recorded using a food frequency questionnaire. RESULTS Compared to controls, cases were older individuals with a higher body mass index (BMI). Physical activity scores were lower in female cases compared to male cases and controls. A significantly higher intake of phosphorus and fat was observed in overall cases (fat in females only). A significantly lower intake of vitamin C and vitamin D was observed in overall cases and the significance of vitamin D persisted on gender-wise bifurcation. On multiple logistic regression analysis, the intake of vitamin D (odds ratio [OR] = 0.79) and vitamin C (OR = 0.97) was inversely associated with the presence of KOA in the observation group, especially in females. Generally, the intake of food servings/day, green leafy vegetables (GLVs), and fats/oils was higher, whereas the intake of fruits, milk/milk products, and meat/poultry was lower in cases compared to controls. CONCLUSION Low intake of vitamin D and vitamin C is a possible risk factor for KOA. Certain food groups, such as fruits, milk/milk products, and meat/poultry are beneficial for KOA. Further studies are needed to elucidate the associations between diet and KOA.
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Affiliation(s)
- Divya Sanghi
- a Department of Orthopaedic Surgery , King George Medical University , Lucknow , INDIA
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Bach FC, Rutten K, Hendriks K, Riemers FM, Cornelissen P, de Bruin A, Arkesteijn GJ, Wubbolts R, Horton WA, Penning LC, Tryfonidou MA. The paracrine feedback loop between vitamin D₃ (1,25(OH)₂D₃) and PTHrP in prehypertrophic chondrocytes. J Cell Physiol 2014; 229:1999-2014. [PMID: 24777663 PMCID: PMC4298802 DOI: 10.1002/jcp.24658] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2014] [Accepted: 04/25/2014] [Indexed: 12/16/2022]
Abstract
The endocrine feedback loop between vitamin D3 (1,25(OH)2D3) and parathyroid hormone (PTH) plays a central role in skeletal development. PTH-related protein (PTHrP) shares homology and its receptor (PTHR1) with PTH. The aim of this study was to investigate whether there is a functional paracrine feedback loop between 1,25(OH)2D3 and PTHrP in the growth plate, in parallel with the endocrine feedback loop between 1,25(OH)2D3 and PTH. This was investigated in ATDC5 cells treated with 10−8 M 1,25(OH)2D3 or PTHrP, Col2-pd2EGFP transgenic mice, and primary Col2-pd2EGFP growth plate chondrocytes isolated by FACS, using RT-qPCR, Western blot, PTHrP ELISA, chromatin immunoprecipitation (ChIP) assay, silencing of the 1,25(OH)2D3 receptor (VDR), immunofluorescent staining, immunohistochemistry, and histomorphometric analysis of the growth plate. The ChIP assay confirmed functional binding of the VDR to the PTHrP promoter, but not to the PTHR1 promoter. Treatment with 1,25(OH)2D3 decreased PTHrP protein production, an effect which was prevented by silencing of the VDR. Treatment with PTHrP significantly induced VDR production, but did not affect 1α- and 24-hydroxylase expression. Hypertrophic differentiation was inhibited by PTHrP and 1,25(OH)2D3 treatment. Taken together, these findings indicate that there is a functional paracrine feedback loop between 1,25(OH)2D3 and PTHrP in the growth plate. 1,25(OH)2D3 decreases PTHrP production, while PTHrP increases chondrocyte sensitivity to 1,25(OH)2D3 by increasing VDR production. In light of the role of 1,25(OH)2D3 and PTHrP in modulating chondrocyte differentiation, 1,25(OH)2D3 in addition to PTHrP could potentially be used to prevent undesirable hypertrophic chondrocyte differentiation during cartilage repair or regeneration.
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Affiliation(s)
- Frances C Bach
- Faculty of Veterinary Medicine, Department of Clinical Sciences of Companion Animals, Utrecht University, Utrecht, The Netherlands
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Saarinen TT, Arikoski P, Holmberg C, Rönnholm K. Intermittent or daily administration of 1-alpha calcidol for nephrectomised infants on peritoneal dialysis? Pediatr Nephrol 2007; 22:1931-8. [PMID: 17851700 DOI: 10.1007/s00467-007-0592-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/01/2006] [Revised: 07/16/2007] [Accepted: 07/16/2007] [Indexed: 11/28/2022]
Abstract
Secondary hyperparathyroidism and renal osteodystrophy are major problems in patients with end-stage renal failure and may result in poor growth in children on dialysis. Whether vitamin D sterols should be given intermittently or daily remains a controversial issue. We studied 16 bilaterally nephrectomised infants with congenital nephrosis of the Finnish type (median age 0.54 years), all on peritoneal dialysis. Nine of them were receiving intermittent 1-alpha calcidol therapy and seven daily 1-alpha calcidol therapy. The target serum parathyroid hormone (PTH) level was 2-3 times the upper limit of normal (ULN). There were no statistically significant differences in PTH values between the groups (1.7-times vs 0.5-times the ULN at 3 months and 3.1-times vs 3.4-times the ULN at 6 months, respectively). The required weekly doses of 1-alpha calcidol were low, and there were no significant differences between the intermittent and daily groups (0.06 microg/kg vs 0.04 microg/kg at 3 months and 0.09 microg/kg vs 0.05 microg/kg at 6 months, respectively). The infants on intermittent 1-alpha calcidol showed significant catch-up growth during dialysis after nephrectomy relative to the infants on daily 1-alpha calcidol (-1.6 SD to -0.7 SD vs -1.4 SD to -1.0 SD, respectively; P < 0.05). Our results indicate that either intermittent or daily vitamin D analogue therapy, if started early, will prevent secondary hyperparathyroidism equally well in children on peritoneal dialysis (PD), but intermittent therapy might be more favourable for growth.
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Affiliation(s)
- Tuure T Saarinen
- Department of Paediatric Nephrology and Transplantation, Hospital for Children and Adolescents, University of Helsinki, Stenbäckinkatu 11, 00290 Helsinki, Finland.
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Sanchez CP, He YZ. Bone growth during daily or intermittent calcitriol treatment during renal failure with advanced secondary hyperparathyroidism. Kidney Int 2007; 72:582-91. [PMID: 17554252 DOI: 10.1038/sj.ki.5002375] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Calcitriol is a standard therapy for secondary hyperparathyroidism in chronic renal failure. We evaluated whether the effect of daily or intermittent calcitriol administration is more efficient in enhancing bone growth in renal failure with advanced secondary hyperparathyroidism in weanling 5/6 nephrectomized rats loaded with phosphorus to induce severe secondary hyperparathyroidism. The animals were treated daily or three times weekly with calcitriol for 4 weeks but the total weekly dose of calcitriol was the same. Although calcitriol increased the serum calcium, it did not lower parathyroid hormone (PTH) or improve tibia and body length. Animals with renal failure and advanced secondary hyperparathyroidism had decreased PTH/PTHrP, which was accompanied by an increase in the cyclin kinase inhibitor p57(Kip2). Calcitriol treatment upregulated the PTH/PTHrP receptor but also increased inhibitors of cell proliferation such as p21(Waf1/Cip1), IGFBP3, and FGFR3. Calcitriol also enhanced markers of chondrocyte differentiation, such as IGF1, Vitamin D receptor, FGF23, and bone morphogenetic protein-7. Receptor activator of nuclear factor-kappabeta ligand levels improved with calcitriol treatment but without changes in osteoprotegerin suggesting an enhancement of osteo/chondroclastogenesis and mineralization. Overall, both daily and intermittent calcitriol had similar effects on endochondral bone growth in phosphorus-loaded rats with renal failure.
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Affiliation(s)
- C P Sanchez
- Department of Pediatrics, University of Wisconsin, School of Medicine and Public Health, 1300 University Avenue, Madison, WI 53706, USA.
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Seikaly MG, Salhab N, Gipson D, Yiu V, Stablein D. Stature in children with chronic kidney disease: analysis of NAPRTCS database. Pediatr Nephrol 2006; 21:793-9. [PMID: 16583244 DOI: 10.1007/s00467-006-0040-7] [Citation(s) in RCA: 86] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/24/2005] [Revised: 11/08/2005] [Accepted: 11/15/2005] [Indexed: 10/24/2022]
Abstract
Despite recent advances in the management of children with chronic kidney disease (CKD), growth remains suboptimal. The purpose of this study was to evaluate factors associated with short stature in children with CKD. We evaluated the chronic renal failure registry of the North American Pediatric Renal Transplant Cooperative Studies (NAPRTCS) to determine the relations among primary diagnosis, age, race, residual renal function, acidosis, anemia, serum phosphorous, calcium, parathyroid hormone (PTH), albumin, and height at entry into the registry in children with CKD. A total of 5,615 patients were entered into the registry between January 1994 and January 2004. We found that older patients, those with glomerular filtration rate (GFR) >50 ml min(-1) 1.73 m(-2), black patients and patients with focal segmental glomerulosclerosis (FSGS) were at lower risk of being short at entry. Anemia (hematocrit below 33%) was an independent risk factor for short stature. Acidosis, serum phosphorous, calcium, albumin and PTH at registration were poor predictors of short stature. Age, race, primary diagnosis, and residual renal function were associated with short stature in children with CKD.
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Affiliation(s)
- Mouin G Seikaly
- Department of Pediatrics, University of Texas Southwestern Medical Center, Dallas, TX, USA.
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Sanchez CP, He YZ. Daily or intermittent calcitriol administration during growth hormone therapy in rats with renal failure and advanced secondary hyperparathyroidism. J Am Soc Nephrol 2005; 16:929-38. [PMID: 15728789 DOI: 10.1681/asn.2003100878] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
Abstract
Growth hormone (GH) improves growth in children with chronic renal failure. The response to GH may be affected by the degree of secondary hyperparathyroidism and concurrent treatment with vitamin D. Forty-six rats underwent 5/6 nephrectomy (Nx) and were given a high-phosphorus diet (Nx-Phos) to induce advanced secondary hyperparathyroidism and divided into the following groups: (1) Nx-Phos (n = 10) received saline, (2) GH at 10 IU/kg per d (Nx-Phos+GH; n = 9), (3) GH and daily calcitriol (D) at 50 ng/kg per d (Nx-Phos+GH+daily D; n = 8), (4) GH and intermittent D (three times weekly) at 350 ng/kg per wk (Nx-Phos+GH+int D; n = 9), and (5) intact-control (n = 10). Serum parathyroid hormone (PTH) levels were elevated in Nx-Phos, but IGF-I levels did not change with growth hormone. Body length, tibial length, and growth plate width did not increase with either GH or calcitriol. Proliferating cell nuclear antigen staining, PTH/PTHrP receptor, bone morphogenetic protein-7, and fibroblast growth factor receptor-3 expression increased with GH alone or with intermittent calcitriol but were slightly diminished during daily calcitriol administration. GH enhanced IGF-I, IGF binding receptor-3, and GH receptor but declined with daily and intermittent calcitriol. Overall, there was no improvement in body length, tibial length, and growth plate width at the end of GH therapy, but selected markers of chondrocyte proliferation and chondrocyte differentiation increased, although these changes were attenuated by calcitriol. The combination of GH and calcitriol that is frequently used in children with renal failure and secondary hyperparathyroidism require further studies to evaluate the optimal dose and frequency of administration to increase linear growth and prevent bone disease.
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Affiliation(s)
- Cheryl P Sanchez
- Department of Pediatrics, University of Wisconsin Medical School, 3590 MSC/Pediatrics, 1300 University Avenue, Madison, WI 53706, USA.
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Schmitt CP, Ardissino G, Testa S, Claris-Appiani A, Mehls O. Growth in children with chronic renal failure on intermittent versus daily calcitriol. Pediatr Nephrol 2003; 18:440-4. [PMID: 12687466 DOI: 10.1007/s00467-003-1091-7] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/10/2002] [Revised: 12/03/2002] [Accepted: 12/03/2002] [Indexed: 01/08/2023]
Abstract
Calcitriol (C) treatment strategies for secondary hyperparathyroidism remain controversial regarding efficacy and safety. In children, intermittent C administration has been suspected of impairing body growth. In a prospective, randomized multicenter study, we compared the effect of daily versus twice weekly C on plasma intact parathyroid hormone (iPTH) levels and growth in 24 prepubertal children with chronic renal insufficiency (mean creatinine clearance 20+/-9 ml/min per 1.73 m(2)). After a 3-week washout period, the patients were randomly assigned to 10 ng/kg per day or 35 ng/kg twice a week oral C. The C dose was kept constant for 2 months and could then be adapted to maintain an iPTH target range of 140-280 pg/ml. Median (range) baseline iPTH levels were 567 (114-1209) pg/ml in the daily and 332 (93-614) pg/ml in the intermittent treatment group ( P=NS). After 12 months, iPTH had decreased to 255 (85-710) and 179 (51-443) pg/ml ( P<0.01). The average weekly dose of C was 76+/-34 and 62+/-34 ng/kg ( P=NS). Five episodes of calcium phosphate product>/=70 occurred in the daily group and four in the intermittent group. The change in height standard deviation score during the study period was not affected by either treatment modality (-0.18+/-0.34 vs. -0.05+/-0.52, P=NS). Daily and intermittent C do not differentially affect growth rate and are equally effective in controlling secondary hyperparathyroidism in children with chronic renal failure.
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Affiliation(s)
- Claus Peter Schmitt
- Division of Pediatric Nephrology, University Children's Hospital, Im Neuenheimer Feld 150, 69120 Heidelberg, Germany.
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Abstract
Growth retardation is a major obstacle to full rehabilitation of children with chronic renal failure (CRF). Several factors have been identified as contributors to impaired linear growth and they include protein and calorie malnutrition, metabolic acidosis, growth hormone resistance, anemia, and renal osteodystrophy. Although therapeutic interventions such as the use of recombinant human growth hormone, recombinant human erythropoietin, and calcitriol have made substantial contributions, the optimal therapeutic strategy remains to be defined. Indeed, growth failure persists in a substantial proportion of children with renal failure and those treated with maintenance dialysis. In addition, the increasing prevalence of adynamic lesions of renal osteodystrophy and its effect on growth have raised concern about the continued generalized use of calcitriol in children with CRF. Recent studies have shown the critical roles of parathyroid hormone-related protein (PTHrP) and the PTH/PTHrP receptor in the regulation of endochondral bone formation. The PTH/PTHrP receptor mRNA expression has been shown to be down-regulated in kidney and growth plate cartilage of animals with renal failure. Differences in the severity of secondary hyperparathyroidism influence not only growth plate morphology but also the expression of selected markers of chondrocyte proliferation and differentiation in these animals. Such findings suggest potential molecular mechanisms by which cartilage and bone development may be disrupted in children with CRF, thereby contributing to diminished linear growth.
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Affiliation(s)
- B D Kuizon
- Department of Pediatrics, UCLA School of Medicine, Los Angeles, California 90095, USA
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Amizuka N, Kwan MY, Goltzman D, Ozawa H, White JH. Vitamin D3 differentially regulates parathyroid hormone/parathyroid hormone-related peptide receptor expression in bone and cartilage. J Clin Invest 1999; 103:373-81. [PMID: 9927498 PMCID: PMC407892 DOI: 10.1172/jci3265] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/1998] [Accepted: 12/18/1998] [Indexed: 11/17/2022] Open
Abstract
Transcription of the mouse parathyroid hormone (PTH)/PTH-related peptide (PTHrP) receptor (PTHR) gene is controlled by promoters P1 and P2. We performed transcript-specific in situ hybridization and found that P2 is the predominant promoter controlling PTHR gene expression in bone and cartilage. Treatment with 1alpha, 25-dihydroxyvitamin D3 (D3) in vivo specifically downregulated P2-specific transcripts in osteoblasts, but not in chondrocytes, under conditions where it enhanced bone resorption. Treatment of the osteoblastic cell line MC3T3-E1 with D3 in vitro reduced expression of both P2-specific transcripts and PTHR protein. This effect was not blocked by cycloheximide, indicating that D3 inhibits PTHR expression by downregulating transcription of the P2 promoter. A similar inhibitory effect of D3 was not observed in the chondrocytic cell line CFK2. Gene-transfer experiments showed that P2, but not P1, is active in both MC3T3-E1 and CFK2 cells, and that D3 specifically inhibited P2 promoter activity in MC3T3-E1, but not in CFK2 cells. Inhibition of P2 activity by D3 required promoter sequences lying more that 1.6 kb upstream of the P2 transcription start site. Thus, the P2 promoter controls PTHR gene expression in both osteoblasts and chondrocytes. D3 downregulates PTHR gene transcription in a cell-specific manner by inhibiting P2 promoter activity in osteoblasts, but not in chondrocytes.
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Affiliation(s)
- N Amizuka
- Department of Oral Anatomy, Niigata University School of Dentistry, Niigata 951-8514, Japan
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Jingushi S, Iwaki A, Higuchi O, Azuma Y, Ohta T, Shida JI, Izumi T, Ikenoue T, Sugioka Y, Iwamoto Y. Serum 1alpha,25-dihydroxyvitamin D3 accumulates into the fracture callus during rat femoral fracture healing. Endocrinology 1998; 139:1467-73. [PMID: 9528922 DOI: 10.1210/endo.139.4.5883] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
1,25-dihydroxyvitamin D3 (1,25(OH)2D3) is thought to be an important systemic factor in the fracture repair process, but the mechanism of action of 1,25(OH)2D3 has not been clearly defined. In this study, the role of 1,25(OH)2D3 in the fracture repair process was analyzed in a rat closed femoral fracture model. The plasma concentration of 1,25(OH)2D3 rapidly decreased on day 3 and continued to decrease to 10 days after fracture. We assessed whether this decrease was based on the accelerated degradation or retardation of the synthesis rate of 1,25(OH)2D3, from 25(OH)D3. After radiolabeled 3H-1,25(OH)2D3 or 3H-25(OH)D3 was injected i.v. into fractured or control (unfractured) rats, the concentrations of 25(OH)D3 and 1,25(OH)2D3 metabolites were measured by HPLC. The plasma concentrations of these radiolabeled metabolites in fractured group were similar to those in control rats early after operation. However, radioactivity in the femurs of fractured rats was higher than that of the control group. Furthermore, the radioactivity was concentrated in the callus of the fractured group analyzed by autoradiography. 1,25(OH)2D3 receptor gene expression was detected early after fracture and, additionally, both in the soft and hard callus on days 7 and 13 after fracture. These results showed that the rapid disappearance of 1,25(OH)2D3 in the early stages after fracture was not due to either increased degradation or decreased synthesis of 1,25(OH)2D3, but rather to increased consumption. Further, these results suggest the possibility that plasma 1,25(OH)2D3 becomes localized in the callus and may regulate cellular events in the process of fracture healing.
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Affiliation(s)
- S Jingushi
- Department of Orthopaedic Surgery, Faculty of Medicine, Kyushu University, Fukuoka, Japan.
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Berry JL, Farquharson C, Whitehead CC, Mawer EB. Growth plate chondrocyte vitamin D receptor number and affinity are reduced in avian tibial dyschondroplastic lesions. Bone 1996; 19:197-203. [PMID: 8853865 DOI: 10.1016/8756-3282(96)00171-8] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Tibial dyschondroplasia (TD) is a condition of rapidly growing poultry in which a mass of unmineralized cartilage extends distally from the tibiotarsal growth plate, leading to deformity and lameness. The lesion is characterized by the accumulation of prehypertrophic chondrocytes, probably because the maturing chondrocytes are unable to differentiate fully. The condition can be prevented by feeding 1,25-(OH)2D3. We have investigated the possibility that vitamin D receptors (VDR), through which 1,25-(OH)2D3 exerts its differentiating effects on chondrocytes, may be defective in TD birds. Chondrocytes were isolated from the proliferating and hypertrophic zones of normal tibiotarsi and from the proliferating zone and lesion of affected birds and receptors were characterized by Scatchard analysis. Results showed that, while cells from the proliferating zone in TD birds had normal receptors, those from the TD lesion had significantly lower numbers and affinity for 1,25-(OH)2D3 compared to all other zones. Lesion VDR had low affinity; Kd 83.9 +/- 20.6 pM compared to 30.0 +/- 2.8, 37.8 +/- 3.1, and 33.0 +/- 4.0 pM (p < 0.001), and low receptor number per cell, 920 +/- 74, compared to 1329 +/- 151, 1664 +/- 167, and 1360 +/- 104 (p < 0.01) in the normal proliferating, normal hypertrophic, and TD proliferating cells, respectively. These findings were confirmed by immunohistochemical localization of VDR in sections of normal and TD growth plates using monoclonal antibody 9A7 gamma. In normal growth plate, most cells were VDR positive with intense staining in the mature hypertrophic chondrocytes; in TD growth plates, proliferating zone cells stained well but signal was largely absent from chondrocytes in the lesion. Image analysis showed integrated nuclear staining density per cell of 168.2 +/- 36.9 arbitrary units in normal hypertrophic cartilage compared to 98.8 +/- 60.2 units in the top of the lesion and 2.2 +/- 2.0 units in the midlesion. We conclude that both numbers and affinity of VDR are reduced in TD and this may explain the failure of chondrocytes to differentiate to the mature form. The adverse consequences of defective receptors may be partly overcome by treatment with 1,25-(OH)2D3.
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Affiliation(s)
- J L Berry
- University of Manchester Bone Disease Research Centre, Department of Medicine, Manchester Royal Infirmary, UK.
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Abstract
To gain insights into 1,25-dihydroxyvitamin D3 receptor (VDR) function during fetal bone development, we examined fetal rat tissues from gestational days 13-21 for the presence and distribution of VDR using immunohistochemistry. Prior to ossification, VDR epitopes were observed in the mesenchyme condensing to form skeletal tissues, on day 13 in the developing vertebral column and limbs, and on day 17 of gestation in developing calvaria. Immunostaining for VDR was seen in proliferating and hypertrophic chondrocytes and in osteoblasts of limb buds and the vertebral column by day 17 of gestation. In calvaria, VDR epitopes were observed in osteoblasts by gestational day 19. VDR immunostaining was also evident in the skin of fetal limbs at all gestational ages examined. We show for the first time that the VDR appears very early in the developing fetal rat skeleton, suggesting that the VDR, in concert with its ligand, 1,25-dihydroxyvitamin D3, may play a role in the differentiation of mesenchymal precursors into bone tissue.
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Affiliation(s)
- J A Johnson
- Nephrology Research Unit, Mayo Clinic/Foundation, Rochester, Minnesota, USA
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