Monthly Archives: March 2014

Taurine Increases Bone Density in Rats

Abstract

Effect of taurine feeding on bone mineral density and bone markers in rats.

The purpose of this study was to investigate the effect of dietary taurine supplementation on bone mineral density (BMD) and bone mineral content (BMC) in rats. Twenty Sprague-Dawley male rats (body weight 200 ± 10 g) were divided into two groups, control and taurine group (2% taurine-supplemented diet). All rats were fed on experimental diet and deionized water and libitum for 6 weeks. Serum alkaline phosphatase (ALP) activity, osteocalcin, PTH, and urinary deoxypyridinoline cross-links value were measured as markers of bone formation and resorption. BMD and BMC were measured using PIXImus (GE Lunar Co., Wisconsin) in spine and femur. The effect of diet on ALP, osteocalcine, and PTH was not significant. There were no significant differences in ALP, osteocalcine, and PTH concentration. Urinary calcium excretion was lower in taurine group than in control group. Femur BMC/weight of taurine group was significantly higher than control group. The results of this study showed the possible role of taurine in bone metabolism in male rats.

Choi MJ, Seo JN
Adv. Exp. Med. Biol. 2013
PMID: 23392870

Taurine Increases Osteoblasts In Vitro

Abstract

Taurine increases cell proliferation and generates an increase in [Mg2+]i accompanied by ERK 1/2 activation in human osteoblast cells.

Taurine has been reported to influence bone metabolism, and its specific transport system, the taurine transporter, is expressed in osteoblasts. The mean [Mg2+]i was 0.51+/-0.01 mM in normal culture media. Taurine caused an increase in [Mg(2+)]i by 0.72+/-0.04 mM in human osteoblast (HOB) cells. This increment in [Mg2+]i was inhibited significantly by PD98059, nifedipine, lidocaine, and imipramine. Taurine was also shown to stimulate the activation of ERK 1/2. This taurine-stimulated ERK 1/2 activation was inhibited by PD98059. In the present study, taurine was shown to increase cell proliferation and generate an increase in [Mg2+]i accompanied by ERK 1/2 activation in HOB cells.

Jeon SH, Lee MY, Kim SJ, Joe SG…
FEBS Lett. Dec 2007
PMID: 18036343

Taurine Induces Connective Tissue Growth Factor in Mouse Osteoblasts

Abstract

Taurine promotes connective tissue growth factor (CTGF) expression in osteoblasts through the ERK signal pathway.

Taurine is found in bone tissue, but its function in skeletal tissue is not fully understood. The present study was undertaken to investigate regulation of gene expression of connective tissue growth factor (CTGF), and the roles of mitogen-activated protein kinases (MAPKs) in murine osteoblast MC3T3-E1 cells treated with taurine. Western blot analysis showed taurine stimulated CTGF protein secretion in a dose- and time-dependent manner. Taurine induced activation of extracellular signal-regulated kinase (ERK), but not p38 and c-jun N-terminal Kinase (JNK), in osteoblasts. Furthermore, pretreatment of osteoblasts with the ERK inhibitor PD98059 abolished the taurine-induced CTGF production. These data indicate that taurine induces CTGF secretion in MC3T3-E1 cells mediated by the ERK pathway, and suggest that osteoblasts are direct targets of taurine.

Yuan LQ, Lu Y, Luo XH, Xie H…
Amino Acids 2007
PMID: 16937320

Taurine Increases Markers of Bone Growth in Human and Mouse Osteoblasts

Abstract

Taurine transporter is expressed in osteoblasts.

Taurine influences bone metabolism and is taken up by cells via a specific transport system, the taurine transporter (TAUT). We report a link between taurine and bone homeostasis by demonstrating transcription and translation of TAUT in bone-forming cells. TAUT was expressed in human primary osteoblasts, the human osteosarcoma osteoblast-like cell line MG63, and the mouse osteoblastic cell line MC3T3-E1. Immunostaining with polyclonal antibodies also demonstrated the presence of TAUT in both human and murine osteoblasts. TAUT mRNA expression and [(3)H]taurine uptake increased during differentiation of MG63 cells in culture. Supplementation of culture medium with taurine enhanced alkaline phosphatase activity and osteocalcin secretion. The regulation and detailed function of taurine and TAUT in bone remain unclear, but our findings suggest a functional role for them in bone homeostasis.

Yuan LQ, Xie H, Luo XH, Wu XP…
Amino Acids Sep 2006
PMID: 16729199

Taurine Leads to Bone Anabolic Action in Mouse Cells

Abstract

[Anti-osteopenic effect of taurine: possible involvement of activated MEK-ERK-Cbfa1 signaling].

Previously we first noted that taurine (TR) has anti-osteopenic effect on low Ca diet-induced osteopenia in rats (1). Employing osteoblastic MC3T3-E1 cells, the mechanism of the anti-osteopenic effect was explored in vitro. TR (1 mM) was found to promote mineralization of extracellular matrices, without affecting alkaline phosphataase activity. Gel shift assay using 32P-labeled OSE2 (osteoblast-specific cis-element 2: the consensus sequence for Cbfa1, refer to 2) indicated that TR (1 mM) increased the nuclear localization of Cbfa1, just as TPH (1-34) (3,4) and bisphosphonates did (5). In addition, TR was found to stimulate ERK phosphorylation. PD98059, a MEK inhibitor, suppressed effects of TR on both Cbfa1 transactivation and ERK activation. The results strongly suggest that TR first activates intracellular MEK-ERK-Cbfa1 signaling system thereby promoting mineralization and finally leading to its bone anabolic action.

Yasutomi C, Nakamuta H, Fujita T, Takenaga T…
Nippon Yakurigaku Zasshi Nov 2002
PMID: 12491800

Taurine Stimulates Osteoblast Growth Markers In Vitro

Abstract

Stimulation of ERK2 by taurine with enhanced alkaline phosphatase activity and collagen synthesis in osteoblast-like UMR-106 cells.

Taurine is present in a variety of tissues and exhibits many important physiological functions in the cell. Even though its functions are well documented in many tissues, its actions on bone cells are largely unknown. Considering a recent finding that taurine is present in the bone, we wished to determine if taurine could have any effects on osteoblast cells. Taurine (10 mM) stimulated alkaline phosphatase activity as well as collagen synthesis. Taurine also stimulated tyrosine phosphorylation of a number of cellular proteins including a 42-kDa protein. The 42-kDa protein was identified as extracellular signal regulated protein kinase 2 (ERK2). A mitogen-activated protein kinase kinase (MEK) inhibitor blocked the taurine-stimulated alkaline phosphatase activity and collagen synthesis. These results suggest that taurine could regulate osteoblast metabolism via ERK2 activation.

Park S, Kim H, Kim SJ
Biochem. Pharmacol. Oct 2001
PMID: 11597579

Taurine Inhibits Osteoblast Apoptosis in Mouse Cells

Abstract

Taurine inhibits serum deprivation-induced osteoblast apoptosis via the taurine transporter/ERK signaling pathway.

Taurine has positive effects on bone metabolism. However, the effects of taurine on osteoblast apoptosis in vitro have not been reported. The aim of this study was to investigate the activity of taurine on apoptosis of mouse osteoblastic MC3T3-E1 cells. The data showed that 1, 5, 10, or 20 mM taurine resulted in 16.7, 34.2, 66.9, or 63.75% reduction of MC3T3-E1 cell apoptosis induced by the serum deprivation (serum-free α-MEM), respectively. Taurine (1, 5, or 10 mM) also reduced cytochrome c release and inhibited activation of caspase-3 and -9, which were measured using fluorogenic substrates for caspase-3/caspase-9, in serum-deprived MC3T3-E1 cells. Furthermore, taurine (10 mM) induced extracellular signal-regulated kinase (ERK) phosphorylation in MC3T3-E1 cells. Knockdown of the taurine transporter (TAUT) or treatment with the ERK-specific inhibitor PD98059 (10 μM) blocked the activation of ERK induced by taurine (10 mM) and abolished the anti-apoptotic effect of taurine (10 mM) in MC3T3-E1 cells. The present results demonstrate for the first time that taurine inhibits serum deprivation-induced osteoblast apoptosis via the TAUT/ERK signaling pathway.

Zhang LY, Zhou YY, Chen F, Wang B…
Braz. J. Med. Biol. Res. Jul 2011
PMID: 21710101 | Free Full Text

Taurine Increases Bone Density in Rats

Abstract

The effects of dietary taurine supplementation on bone mineral density in ovariectomized rats.

This study was performed to evaluate the effect of a diet rich in taurine (2.0 g/100 g) on bone metabolism in ovariectomized (OVX) rats. All rats were fed deionized water during the experimental period. Bone mineral density (BMD) and bone mineral content (BMC) of spine and femur were measured. Serum and urinary calcium and phosphorus content were determined. The levels serum osteocalcin and alkaline phosphatase (ALP) were used to assess bone formation. The rate of bone resorption was measured by the deoxypyridinoline (DPD) crosslink immunoassay and corrected for creatinine. Urinary Ca and P excretion, serum osteocalcin content, and the crosslink value were not significantly different between the Sham groups. The taurine supplemented, Sham group had higher spinal and femur BMC than those of the untreated control group, but the difference was not statistically significant. However, the taurine supplemented, Sham group had significantly higher spine and femur BMC per weight than those of the untreated control group. Within the OVX group, the taurine supplemented group had a lower crosslink value than the casein group. The taurine supplemented, OVX group had higher femur bone mineral content per weight than those of the control, OVX group, but the difference was not statistically significant. A study examining the long-term effect of taurine supplementation in humans is warranted.

Choi MJ, DiMarco NM
Adv. Exp. Med. Biol. 2009
PMID: 19239165

Review: Nutrients Involved in Maintaining Healthy Bone

Abstract

Update on nutrients involved in maintaining healthy bone.

Osteoporosis is a leading cause of morbidity and mortality in the elderly and influences quality of life, as well as life expectancy. Currently, there is a growing interest among the medical scientists in search of specific nutrients and/or bioactive compounds of natural origin for the prevention of disease and maintenance of bone health. Although calcium and vitamin D have been the primary focus of nutritional prevention of osteoporosis, a recent research has clarified the importance of several additional nutrients and food constituents. Based on this review of the literature, supplementation with vitamins B, C, K, and silicon could be recommended for proper maintenance of bone health, although further clinical studies are needed. The results of studies on long-chain polyunsaturated fatty acids, potassium, magnesium, copper, selenium, and strontium are not conclusive, although studies in vitro and in animal models are interesting and promising.

Rondanelli M, Opizzi A, Perna S, Faliva MA
Endocrinol Nutr Apr 2013
PMID: 23273614

Garlic Oil Prevents Bone Loss in Ovariectomized Rats

Abstract

Role of peritoneal macrophages and lymphocytes in the development of hypogonadal osteoporosis in an ovariectomized rat model: possible phytoestrogenic efficacy of oil extract of garlic to preserve skeletal health.

This study was to examine whether skeletal health deterioration in the hypogonadal situation is a consequence of an alteration in the functional status of peripheral mononuclear cells and its amelioration, if any, by an oil extract of garlic. The results suggest that hypogonadism-induced oxidative stress of peritoneal macrophages and lymphocytes could be reduced by supplementation with an oil extract of garlic. However, estrogen deficiency did not cause any significant change in DNA fragmentation of peritoneal macrophages. The hypogonadism-induced increase in the serum levels of IL-6 and TNF-alpha were significantly reduced by an oil extract of garlic. Further, such supplementation could revive the hypogonadism-induced decrease in serum estrogen titer and counter-balance the increase in bone turnover as determined by low bone tensile strength and alterations in bone related biochemical variables such as urinary calcium, hydroxyproline, calcium to creatinine ratio and serum tartrate resistant acid phosphatase activity (TRAP). The garlic oil supplemented partial recovery of the serum estrogen titer in hypogonadal rats was found to be persistently associated with reduced oxidative stress of peritoneal macrophages and lymphocytes, reduced serum interleukins and better preservation of bone mass. This study proposes that the hypogonadism-induced bone loss has a direct correlation with the functional status of lymphocytes and peritoneal macrophages, and garlic can prevent this.

Mukherjee M, Das AS, Das D, Mukherjee S…
Phytother Res Nov 2007
PMID: 17600860