scholarly journals Magnesium Picolinate Improves Bone Formation by Regulation of RANK/RANKL/OPG and BMP-2/Runx2 Signaling Pathways in High-Fat Fed Rats

Nutrients ◽  
2021 ◽  
Vol 13 (10) ◽  
pp. 3353
Author(s):  
Emre Sahin ◽  
Cemal Orhan ◽  
Tansel Ansal Balci ◽  
Fusun Erten ◽  
Kazim Sahin

Magnesium (Mg) deficiency may affect bone metabolism by increasing osteoclasts, decreasing osteoblasts, promoting inflammation/oxidative stress, and result in subsequent bone loss. The objective of the present study was to identify the molecular mechanism underlying the bone protective effect of different forms of Mg (inorganic magnesium oxide (MgO) versus organic magnesium picolinate (MgPic) compound) in rats fed with a high-fat diet (HFD). Forty-two Wistar albino male rats were divided into six group (n = 7): (i) control, (ii) MgO, (iii) MgPic, (iv) HFD, (v) HFD + MgO, and (vi) HFD + MgPic. Bone mineral density (BMD) increased in the Mg supplemented groups, especially MgPic, as compared with the HFD group (p < 0.001). As compared with the HFD + MgO group, the HFD + MgPic group had higher bone P (p < 0.05) and Mg levels (p < 0.001). In addition, as compared to MgO, MgPic improved bone formation by increasing the levels of osteogenetic proteins (COL1A1 (p < 0.001), BMP2 (p < 0.001), Runx2 (p < 0.001), OPG (p < 0.05), and OCN (p < 0.001), IGF-1 (p < 0.001)), while prevented bone resorption by reducing the levels of RANK and RANKL (p < 0.001). In conclusion, the present data showed that the MgPic could increase osteogenic protein levels in bone more effectively than MgO, prevent bone loss, and contribute to bone formation in HFD rats.

Nutrients ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 1666
Author(s):  
Dean S. Ross ◽  
Tzu-Hsuan Yeh ◽  
Shalinie King ◽  
Julia Mathers ◽  
Mark S. Rybchyn ◽  
...  

Increased risks of skeletal fractures are common in patients with impaired glucose handling and type 2 diabetes mellitus (T2DM). The pathogenesis of skeletal fragility in these patients remains ill-defined as patients present with normal to high bone mineral density. With increasing cases of glucose intolerance and T2DM it is imperative that we develop an accurate rodent model for further investigation. We hypothesized that a high fat diet (60%) administered to developing male C57BL/6J mice that had not reached skeletal maturity would over represent bone microarchitectural implications, and that skeletally mature mice would better represent adult-onset glucose intolerance and the pre-diabetes phenotype. Two groups of developing (8 week) and mature (12 week) male C57BL/6J mice were placed onto either a normal chow (NC) or high fat diet (HFD) for 10 weeks. Oral glucose tolerance tests were performed throughout the study period. Long bones were excised and analysed for ex vivo biomechanical testing, micro-computed tomography, 2D histomorphometry and gene/protein expression analyses. The HFD increased fasting blood glucose and significantly reduced glucose tolerance in both age groups by week 7 of the diets. The HFD reduced biomechanical strength, both cortical and trabecular indices in the developing mice, but only affected cortical outcomes in the mature mice. Similar results were reflected in the 2D histomorphometry. Tibial gene expression revealed decreased bone formation in the HFD mice of both age groups, i.e., decreased osteocalcin expression and increased sclerostin RNA expression. In the mature mice only, while the HFD led to a non-significant reduction in runt-related transcription factor 2 (Runx2) RNA expression, this decrease became significant at the protein level in the femora. Our mature HFD mouse model more accurately represents late-onset impaired glucose tolerance/pre-T2DM cases in humans and can be used to uncover potential insights into reduced bone formation as a mechanism of skeletal fragility in these patients.


Endocrinology ◽  
2016 ◽  
Vol 157 (7) ◽  
pp. 2621-2635 ◽  
Author(s):  
Seong Hee Ahn ◽  
Sook-Young Park ◽  
Ji-Eun Baek ◽  
Su-Youn Lee ◽  
Wook-Young Baek ◽  
...  

Free fatty acid receptor 4 (FFA4) has been reported to be a receptor for n-3 fatty acids (FAs). Although n-3 FAs are beneficial for bone health, a role of FFA4 in bone metabolism has been rarely investigated. We noted that FFA4 was more abundantly expressed in both mature osteoclasts and osteoblasts than their respective precursors and that it was activated by docosahexaenoic acid. FFA4 knockout (Ffar4−/−) and wild-type mice exhibited similar bone masses when fed a normal diet. Because fat-1 transgenic (fat-1Tg+) mice endogenously converting n-6 to n-3 FAs contain high n-3 FA levels, we crossed Ffar4−/− and fat-1Tg+ mice over two generations to generate four genotypes of mice littermates: Ffar4+/+;fat-1Tg−, Ffar4+/+;fat-1Tg+, Ffar4−/−;fat-1Tg−, and Ffar4−/−;fat-1Tg+. Female and male littermates were included in ovariectomy- and high-fat diet-induced bone loss models, respectively. Female fat-1Tg+ mice decreased bone loss after ovariectomy both by promoting osteoblastic bone formation and inhibiting osteoclastic bone resorption than their wild-type littermates, only when they had the Ffar4+/+ background, but not the Ffar4−/− background. In a high-fat diet-fed model, male fat-1Tg+ mice had higher bone mass resulting from stimulated bone formation and reduced bone resorption than their wild-type littermates, only when they had the Ffar4+/+ background, but not the Ffar4−/− background. In vitro studies supported the role of FFA4 as n-3 FA receptor in bone metabolism. In conclusion, FFA4 is a dual-acting factor that increases osteoblastic bone formation and decreases osteoclastic bone resorption, suggesting that it may be an ideal target for modulating metabolic bone diseases.


2020 ◽  
Vol 4 (Supplement_2) ◽  
pp. 1795-1795
Author(s):  
Chen Du ◽  
Gina Tran ◽  
Victorine Imrhan ◽  
Chandan Prasad ◽  
Parakat Vijayagopal ◽  
...  

Abstract Objectives The purpose of this study was to compare the effects of alpha tocopherol, gamma tocopherol, and the combination of alpha and gamma tocopherols on bone mineral density (BMD), bone mineral content (BMC), and bone metabolism in C57BL/6 J mice fed a high-fat diet. Methods A total of 75 male C57BL/6 mice were randomized to either a low fat diet (LFD) with 6% fat, a high fat diet (HFD) with 20% fat, HFD supplemented with alpha tocopherol (AT), gamma tocopherol (GT), or the combination of AT and GT. LFD and HFD were provided to corresponding groups of mice without vitamin E isoform supplements for 15 weeks to induce bone loss. At the end of the 15 weeks, AT, GT, and a combination of AT and GT were added to 3 of the HFD groups and fed for 10 weeks. LFD group and one of the HFD groups were continued on the same diet for another 10 weeks without additional supplements. All mice were euthanized at the end of the 25 weeks period. Left and right fibula bones were excised, cleaned, and scanned using the Lunar PIXImus dual-energy x-ray absorptiometry (DEXA) densitometer to assess BMD, BMC, lean tissue, and fat tissue content. Serum biomarkers of bone metabolism were evaluated post euthanization. Results HFD resulted in significantly lower fibular BMD and higher tibial bone fat content in comparison to LFD. Animals in the HFD supplemented with GT, but not AT, showed significantly reduced effect of HFD in lowering BMD. Additionally, in the group fed HFD supplemented with GT, a significantly higher concentration of alkaline phosphatase (ALP) and N-terminal propeptide of type I procollagen (PINP) were noted, compared to LFD. This may be indicative of increased bone formation resulting from GT incorporated into the HFD diet. Conclusions The findings of the study suggest that different isoforms of vitamin E affect bone density and bone metabolism differently. Within the different isoforms of vitamin E, gamma tocopherol may have protective effects in bone, especially in the situation of high fat diet induced bone loss. Further examination of the mechanistic action of vitamin E isoforms on skeletal health is warranted. Funding Sources Texas Woman's University.


2018 ◽  
Vol 44 ◽  
pp. 246-254 ◽  
Author(s):  
Sok Kuan Wong ◽  
Kok-Yong Chin ◽  
Farihah Hj Suhaimi ◽  
Fairus Ahmad ◽  
Soelaiman Ima-Nirwana

Bone Research ◽  
2021 ◽  
Vol 9 (1) ◽  
Author(s):  
Sarah Kim ◽  
Holger Henneicke ◽  
Lauryn L. Cavanagh ◽  
Eugenie Macfarlane ◽  
Lee Joanne Thai ◽  
...  

AbstractChronic high-fat diet (HFD) consumption not only promotes obesity and insulin resistance, but also causes bone loss through mechanisms that are not well understood. Here, we fed wild-type CD-1 mice either chow or a HFD (43% of energy from fat) for 18 weeks; HFD-fed mice exhibited decreased trabecular volume (−28%) and cortical thickness (−14%) compared to chow-fed mice. In HFD-fed mice, bone loss was due to reduced bone formation and mineral apposition, without obvious effects on bone resorption. HFD feeding also increased skeletal expression of sclerostin and caused deterioration of the osteocyte lacunocanalicular network (LCN). In mice fed HFD, skeletal glucocorticoid signaling was activated relative to chow-fed mice, independent of serum corticosterone concentrations. We therefore examined whether skeletal glucocorticoid signaling was necessary for HFD-induced bone loss, using transgenic mice lacking glucocorticoid signaling in osteoblasts and osteocytes (HSD2OB/OCY-tg mice). In HSD2OB/OCY-tg mice, bone formation and mineral apposition rates were not suppressed by HFD, and bone loss was significantly attenuated. Interestingly, in HSD2OB/OCY-tg mice fed HFD, both Wnt signaling (less sclerostin induction, increased β-catenin expression) and glucose uptake were significantly increased, relative to diet- and genotype-matched controls. The osteocyte LCN remained intact in HFD-fed HSD2OB/OCY-tg mice. When fed a HFD, HSD2OB/OCY-tg mice also increased their energy expenditure and were protected against obesity, insulin resistance, and dyslipidemia. Therefore, glucocorticoid signaling in osteoblasts and osteocytes contributes to the suppression of bone formation in HFD-fed mice. Skeletal glucocorticoid signaling is also an important determinant of glucose uptake in bone, which influences the whole-body metabolic response to HFD.


1958 ◽  
Vol 194 (2) ◽  
pp. 387-389
Author(s):  
Willard A. Krehl ◽  
Joseph J. Barboriak

Magnesium-deficient, high-fat and high-carbohydrate diets containing 5 mg magnesium/100 gm were fed to weanling albino rats in order to learn more about the possible relationship between magnesium and lipid metabolism. After 10 weeks of feeding, the blood cholesterol levels of the fat-fed male rats were significantly higher than those fed the carbohydrate diet. The differences between the two female groups were not so pronounced. Serum protein levels decreased in both high-fat and high-carbohydrate-fed animals; the decrease was more evident in the latter groups. Retardation of growth was more pronounced in the groups fed the high-fat diet.


2021 ◽  
Author(s):  
Rachel Freid ◽  
Amira I Hussein ◽  
Jennifer J Schlezinger

AbstractRisk factors for poor bone quality include estrogen loss at menopause, a high fat diet and exposures to drugs/chemicals that activate peroxisome proliferator activated receptor gamma (PPARγ). We observed that the PPARγ and retinoid X receptor dual ligand, tributyltin (TBT), repressed periosteal bone formation but enhanced trabecular bone formation in female C57BL6/J mice. Here, we examined the interaction of diet, ovariectomy (OVX) and TBT exposure on bone structure. C57BL/6J mice underwent either sham surgery or OVX at 10 weeks of age. At 12 weeks of age, they were placed on a low (10% kcal) or high (45% kcal) fat, sucrose-matched diet and treated with Vh or TBT (1 or 5 mg/kg) for 14 weeks. OVX increased body weight gain in mice on either diet. TBT enhanced body weight gain in intact mice fed a high fat diet, but decreased weight gain in OVX mice. Elemental tin concentrations increased dose-dependently in bone. TBT had marginal effects on cortical and trabecular bone in intact mice fed a low- or high- fat diet. OVX caused a reduction in cortical and trabecular bone, regardless of diet. In high-fat fed OVX mice, TBT further reduced cortical thickness, bone area and total area. Interestingly, TBT protected against OVX-induced trabecular bone loss in low fat fed mice. The protective effect of TBT was nullified by the high fat diet and accompanied by a significant decrease in serum bone formation markers. Our novel observations will provide new information on basic bone biology, potential therapeutic targets and toxicological pathways.


2021 ◽  
Vol 91 ◽  
pp. 108598
Author(s):  
Diego Hernández-Saavedra ◽  
Laura Moody ◽  
Xinyu Tang ◽  
Zachary J. Goldberg ◽  
Alex P. Wang ◽  
...  

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