1
|
Wakefield CB, Yumol JL, Sacco SM, Sullivan PJ, Comelli EM, Ward WE. Bone structure is largely unchanged in growing male CD-1 mice fed lower levels of vitamin D and calcium than in the AIN-93G diet. Bone Rep 2019; 10:100191. [PMID: 30656199 PMCID: PMC6324019 DOI: 10.1016/j.bonr.2018.100191] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/13/2018] [Revised: 11/29/2018] [Accepted: 12/27/2018] [Indexed: 11/15/2022] Open
Abstract
Background Calcium (Ca) and vitamin D (vit D) in the AIN-93G diet may be higher than required for healthy bone development, and mask the potential benefit of a dietary intervention. Objective The objective was to determine if lower levels of Ca and vit D than is present in the AIN-93G diet supports bone development in growing male CD-1 mice. Methods Weanling male CD-1 mice were randomized to modified AIN-93G diets containing either 100 (Trial 1) or 400 (Trial 2) IU vit D/kg diet within one of two or three Ca levels (0.35, 0.30, or 0.25% Ca diet in Trial 1 or 0.35% or 0.25% in Trial 2) or the AIN-93G diet (1000 IU/kg vit D and 0.5% Ca) from weaning to 4 months of age (n = 13–15/group). At 2 and 4 months of age, BMD and structural properties of the tibia were analyzed in vivo. Structure of lumbar vertebra 4 (L4) and mandible, and femur strength were assessed ex vivo at age 4 months. Results There were no differences in tibia, L4, and mandible structure between the AIN-93G diet and the 0.35% Ca groups at either vit D level. A few structure outcomes were compromised with the 0.25 and/or 0.3% Ca diets but there were no differences in femur biomechanical strength compared to AIN-93G group in either Trial. Conclusion At 400 or 100 IU vit D/kg diet, Ca can be lowered to 0.35% without detriment to BMD or bone structure while bone strength is not altered at lower Ca (0.25%) compared to CD-1 mice fed AIN-93G diet. Because of genetic variation in CD-1 mice among different breeding facilities, results in CD-1 mice from other facilities may differ from the present study.
Collapse
Key Words
- AIN-93G
- BMD, bone mineral density
- BV/TV, percent bone volume
- Bone mineral density
- Bone structure
- Ca, calcium
- Calcium
- Conn.D, connectivity density
- Ct.Ar/Tt.Ar, cortical area fraction
- Ct.Th, cortical thickness
- DA, degree anisotropy
- Ec.Pm, endocortical perimeter
- Ecc., eccentricity
- L4, lumbar vertebra 4
- Ma.Ar, medullary area
- Ps.Pm, periosteal perimeter
- ROI, region of interest
- Rodent diet
- Tb.N, trabecular number
- Tb.Sp, trabecular separation
- Tb.Th, trabecular thickness
- Vitamin D
- vit D, vitamin D
- μCT, micro-computed tomography
Collapse
Affiliation(s)
| | - Jenalyn L. Yumol
- Health Sciences, Brock University, St. Catharines, Ontario, Canada
| | - Sandra M. Sacco
- Kinesiology, Brock University, St. Catharines, Ontario, Canada
| | | | - Elena M. Comelli
- Kinesiology, Brock University, St. Catharines, Ontario, Canada
- Nutritional Sciences, University of Toronto, Toronto, Ontario, Canada
- Joannah and Brian Lawson Centre for Child Nutrition, University of Toronto, Toronto, Ontario, Canada
| | - Wendy E. Ward
- Kinesiology, Brock University, St. Catharines, Ontario, Canada
- Health Sciences, Brock University, St. Catharines, Ontario, Canada
- Nutritional Sciences, University of Toronto, Toronto, Ontario, Canada
- Corresponding author at: Department of Kinesiology, Faculty of Applied Health Science, Brock University, 1812 Sir Isaac Brock Way, St Catharines, Ontario L2S 3A1, Canada.
| |
Collapse
|
2
|
Abstract
Intake of high-fat/high-sucrose (HFS) diet or high fat diet influences bone metabolism in young rodents, but its effects on bone properties of aged rodents still remain unclear. This study aimed to examine the effects of HFS diet intake on trabecular bone architecture (TBA) and cortical bone geometry (CBG) in aged rats. Fifteen male Wistar rats over 1 year were randomly divided into two groups. One group was fed a standard laboratory diet (SLD) and the other group was fed a HFS diet for six months. The femur/tibia, obtained from both groups at the end of experimental period, were scanned by micro-computed tomography for TBA/CBG analyses. Serum biochemical analyses were also conducted. Body weight was significantly higher in the HFS group than in the SLD group. In both femur and tibia, the HFS group showed higher trabecular/cortical bone mass in reference to bone mineral content, volume bone mineral density and TBA/CBG parameters compared with the SLD group. In addition, serum calcium, inorganic phosphorus, total protein, triacylglycerol, HDL and TRACP-5b levels were significantly higher in the HFS group than in the SLD group. There were good correlations between body weight and bone parameters in the femur and tibia. These results suggest that HFS diet intake results in higher bone mass in aged rats. Such effects of HFS diet intake might have been induced by increased body weight.
Collapse
Key Words
- ALP, alkaline phosphatase
- Aged rats
- BMC, bone mineral content
- BMD, bone mineral density
- BV, bone volume
- BV/TV, bone volume fraction
- CBG, cortical bone geometry
- CV, cortical bone volume
- CV/(CV + MV), cortical volume fraction
- Ca, calcium
- Conn.D, connectivity density
- Cortical bone geometry
- Ct.Ar, cortical bone sectional area
- Ct.Th, cortical bone thickness
- DXA, dual-energy X-ray absorptiometry
- Ec.Pm, endocortical perimeter
- HDL, high-density lipoprotein cholesterol
- HFD, high fat diet
- HFS, high-fat/high-sucrose
- High-fat sucrose diet
- IP, inorganic phosphorus
- LDL, low-density lipoprotein cholesterol
- MV, medullary volume
- Micro-computed tomography
- OC, osteocalcin
- Ps.Pm, periosteal perimeter
- SLD, standard laboratory diet
- TBA, trabecular bone architecture
- TBPf, trabecular bone pattern factor
- TC, total cholesterol
- TG, triacylglycerol
- TMD, tissue mineral density
- TP, total protein
- TRACP-5b, tartrate-resistant acid phosphatase-5b
- TV, tissue volume
- Tb.N, trabecular number
- Tb.Sp, trabecular separation
- Tb.Th, trabecular thickness
- Tb.W, trabecular width
- Trabecular bone architecture
- VOI, volume of interest
- micro-CT, x-ray micro-computed tomography
- vBMD, volume BMD
Collapse
Affiliation(s)
- Akira Minematsu
- Department of Physical Therapy, Faculty of Health Science, Kio University, 4-2-2 Umaminaka, Koryo-cho, Kitakatsuragi-gun, Nara 635-0832, Japan
| | - Yasue Nishii
- Department of Physical Therapy, Faculty of Health Science, Kio University, 4-2-2 Umaminaka, Koryo-cho, Kitakatsuragi-gun, Nara 635-0832, Japan
| | - Susumu Sakata
- Department of Physiology, Nara Medical University, 840 Shijou-cho, Kashihara, Nara 634-8521, Japan
| |
Collapse
|
3
|
Yumol JL, Wakefield CB, Sacco SM, Sullivan PJ, Comelli EM, Ward WE. Bone development in growing female mice fed calcium and vitamin D at lower levels than is present in the AIN-93G reference diet. Bone Rep 2018; 8:229-38. [PMID: 29955642 DOI: 10.1016/j.bonr.2018.05.004] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/25/2018] [Revised: 05/09/2018] [Accepted: 05/17/2018] [Indexed: 12/31/2022] Open
Abstract
Background The AIN-93G reference (REF) diet is used to allow the comparison within and between studies of different research groups but its levels of vitamin D (vit D) and calcium (Ca) may be higher than required for healthy bone structure and bone mineral density (BMD). Objective To determine if lower dietary levels of Ca (3.5, 3 or 2.5 g Ca/kg diet) at 1 of 2 levels of vit D (100 or 400 IU/kg diet) supports similar development of bone structure and BMD compared to AIN-93G reference (REF) diet in female CD-1 mice at 2 and 4 months of age. Methods Within a trial, weanling female mice (n = 12–15/group) were randomized to 1 of 4 diets until necropsy at 4 months of age: Trial 1: 100 IU vit D/kg + 3.5, 3 or 2.5 g Ca/kg diet or 1000 IU vit D/kg + 5 g Ca/kg diet (REF); and Trial 2: 400 IU vit D/kg + 3.5, 3 or 2.5 g Ca/kg diet or 1000 IU vit D/kg + 5 g/kg diet (REF). At age 2 and 4 months, in vivo bone structure and BMD were assessed using micro-computed tomography (μCT) at the proximal and midpoint tibia. At age 4 months, lumbar vertebra 4 (L4) and mandible structure were analyzed ex vivo, femur strength at midpoint and neck was assessed and serum 25(OH)D3 and PTH were quantified. Results For Trial 1 (100 IU vit D/kg), there were no differences in tibia structure at age 2 and 4 months nor L4 or mandible structure or femur strength at the midpoint or neck at 4 months of age despite lower serum 25(OH)D3 among all groups compared to REF. For Trial 2 (400 IU vit D/kg), mice fed 2.5 g Ca/kg diet had lower (p < 0.05) Ct.Ar/Tt.Ar and Ct.Th at the tibia midpoint compared to REF. Furthermore, Ct.Th. was greater in REF and 3.5 g Ca/kg diet compared to 2.5 g Ca/kg diet at age 2 but not 4 months of age. At L4, BV/TV was lower (p < 0.05) in the 3 g Ca/kg diet group compared to REF at age 4 months. There were no differences among groups for serum 25(OH)D3 or femur strength at the midpoint or neck. Serum PTH was not elevated compared to REF in either Trial. Conclusion Lowering both dietary vit D (100 IU/kg) and Ca (2.5 g/kg) in AIN-93G diet did not result in differences in bone development of female CD-1 mice at early adulthood. Translational relevance of bone studies conducted using the AIN-93G diet may be affected by its high vit D and Ca content.
Collapse
Key Words
- AIN93G
- ANOVA, analysis of variance
- BMC, bone mineral content
- BMD, bone mineral density
- BV/TV, percent bone volume
- Bone mineral density
- Bone structure
- Ca, calcium
- Calcium
- Conn.Dn, connectivity density
- Ct.Ar/Tt.Ar, cortical area fraction
- Ct.Th, cortical thickness
- DA, degree anisotropy
- Ec.Pm, endocortical perimeter
- Ecc, mean eccentricity
- ISO, isoflavones
- L4, lumbar vertebrae 4
- Ma.Ar, medullary area
- Micro-computed tomography
- P, phosphorus
- PBM, peak bone mass
- PTH, parathyroid hormone
- Ps.Pm, periosteum perimeter
- REF, AIN-93G reference diet
- ROI, region of interest
- SEM, standard error mean
- Tb.N, trabecular number
- Tb.Sp, trabecular separation
- Tb.Th, trabecular thickness
- Vitamin D
- vit D, vitamin D
- μCT, micro computed tomography
Collapse
|
4
|
Taylor S, Hu R, Pacheco E, Locher K, Pyrah I, Ominsky MS, Boyce RW. Differential time-dependent transcriptional changes in the osteoblast lineage in cortical bone associated with sclerostin antibody treatment in ovariectomized rats. Bone Rep 2018; 8:95-103. [PMID: 29955627 DOI: 10.1016/j.bonr.2018.03.002] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/26/2017] [Revised: 02/15/2018] [Accepted: 03/13/2018] [Indexed: 12/13/2022] Open
Abstract
Inhibition of sclerostin with sclerostin antibody (Scl-Ab) results in stimulation of bone formation on cancellous (Cn), endocortical (Ec), and periosteal (Ps) surfaces in rodents and non-human primates. With long-term dosing of Scl-Ab, the increase in bone formation is not sustained, attenuating first on Cn surfaces and later on Ec and Ps surfaces. In Cn bone, the attenuation in bone formation (self-regulation) is associated with transcriptional changes in the osteocyte (OCy) that would limit mitogenesis and are sustained with continued dosing. The expression changes in Cn OCy occur coincident with a decrease in osteoprogenitor (OP) numbers that may directly or indirectly be a consequence of the transcriptional changes in the OCy to limit OP proliferation. To characterize the Scl-Ab–mediated changes in cortical (Ct) bone and compare these changes to Cn bone, densitometric, histomorphometric, and transcriptional analyses were performed on femur diaphyses from aged ovariectomized rats. Animals were administered 50 mg/kg/wk of Scl-Ab or vehicle for up to 6 months (183 days), followed by a treatment-free period (up to 126 days). Scl-Ab increased Ct mass and area through day 183, which declined slightly when treatment was discontinued. Ps and Ec bone formation was sustained through the dosing on both Ct surfaces, with evidence of a decline in bone formation only at day 183 on the Ec surface. This is in contrast to Cn bone, where reduced bone formation was observed after day 29. TaqMan analysis of 60 genes with functional roles in the bone using mRNA isolated from laser capture micro-dissection samples enriched for Ec osteoblasts and Ct OCy suggest a pattern of gene expression in Ct bone that differed from Cn, especially in the OCy, and that corresponded to observed differences in the timing of phenotypic changes. Notable with Scl-Ab treatment was a “transcriptional switch” in Ct OCy at day 183, coincident with the initial decline in bone formation on the endocortex. A consistent sustained increase of expression for most genes in response to Scl-Ab was observed from day 8 through day 85 at the times of maximal bone formation on both Ct surfaces; however, at day 183, this increase was reversed, with expression of these genes generally returning to control values or decreasing compared to vehicle. Genes exhibiting this pattern included Wnt inhibitors Sost and Dkk1, though both had been up-regulated until the end of dosing in Cn OCy. Changes in cell cycle genes such as Cdkn1a and Ndrg1 in Ct OCy suggested up-regulation of p53 signaling, as observed in Cn OCy; however, unlike in Cn bone, p53 signaling was not associated with decreased bone formation and was absent at day 183, when bone formation began to decline on the Ec surface. These data demonstrate involvement of similar molecular pathways in Ct and Cn bone in response to Scl-Ab but with a different temporal relationship to bone formation and suggest that the specific mechanism underlying self-regulation of Scl-Ab–induced bone formation may be different between Cn and Ct bone. Sclerostin antibody stimulates bone formation that attenuates over time. Attenuation (self-regulation) is delayed in cortical versus cancellous bone. Self-regulation coincides with transcriptional changes in cortical osteocytes. Response of Wnt inhibitors differs between cortical and cancellous bone. Results suggest a distinct mechanism for self-regulation in cortical bone.
Collapse
Key Words
- ANOVA, analysis of variance
- Anabolics
- BMC, bone mineral content
- BMP, bone morphogenetic protein
- BS, bone surface
- Bone
- Cn, cancellous
- Ct, cortical
- Ec, endocortical
- Ec.Pm, endocortical perimeter
- LC, lining cells
- LCM, laser capture micro-dissection
- MS/BS, mineralizing surface
- OB, osteoblast(s)
- OCy, osteocyte(s)
- OP, osteoprogenitor(s)
- OPG, osteoprotegerin
- OVX, ovariectomized
- Osteoporosis
- Ps, periosteal
- Ps.Pm, periosteal perimeter
- RANKL, receptor activator of nuclear factor kappa-B ligand
- Scl-Ab, sclerostin antibody
- Scl-AbVI, 50 mg/kg of a Scl-Ab
- TFP, treatment-free period
- TGF, transforming growth factor
- TP, treatment period
- Therapeutics
- VEH, vehicle
- Wnt signaling
- pQCT, peripheral quantitative computed tomography
- s.c., subcutaneous
Collapse
|