Low sirtuin 1 levels in human osteoarthritis subchondral osteoblasts lead to abnormal sclerostin expression which decreases Wnt/β-catenin activity.
Wnt/β-catenin (cWnt) signaling plays a key role in osteogenesis by promoting the differentiation and mineralization of osteoblasts, activities altered in human osteoarthritic subchondral osteoblast (OA Ob). Sclerostin (SOST) has been shown to alter cWnt signaling. Sirtuin 1 (SIRT1) acts as a novel bone regulator and represses SOST levels in Ob. However the role of SIRT1 and SOST in OA Ob remains unknown. Herein, we explored the role played by SIRT1 and SOST on the abnormal mineralization and cWnt signaling in OA Ob.
Primary human normal and OA Ob were prepared from tibial plateaus. SOST levels were evaluated by immunohistochemistry, the expression and production of genes by qRT-PCR and WB analysis. Their inhibitions were performed using siRNA. cWnt signaling was measured by the TOPflash TCF/lef luciferase reporter assay. Mineralization was determined by alizarin red staining.
SOST levels were significantly increased in OA Ob compared to normal and were linked with elevated TGF-β1 levels in these cells. SIRT1 expression was significantly reduced in OA Ob compared to normal yet not modified by TGF-β1. Specific inhibition of SIRT1 increased TGF-β1 and SOST expressions in OA Ob, while stimulating SIRT1 activity with β-Nicotinamide mononucleotide reduced the expression of TGF-β1 and SOST, and increased mineralization in OA Ob. Resveratrol also reduced SOST expression in OA Ob. Reduced cWnt signaling, β-catenin levels, and mineralization in OA Ob were all corrected via reducing SOST expression.
These data indicate that high level of SOST is responsible, in part, for the reduced cWnt and mineralization of human OA Ob, which in turn is linked with abnormal SIRT1 levels in these pathological cells.
Abed É, Couchourel D, Delalandre A, Duval N…
Bone Feb 2014
Resveratrol Increases Bone Mineral Density and Bone Alkaline Phosphatase in Obese Men: A Randomized Placebo-Controlled Trial.
Context: Metabolic syndrome (MetS) is associated with low-grade inflammation, which may harmfully affect bone. Resveratrol (RSV) possesses anti-inflammatory properties, and rodent studies suggest bone protective effects. Objective: This study sought to evaluate effects of RSV treatment on bone in men with MetS. Setting and Design: The study was conducted at Aarhus University Hospital as a randomized, double-blinded, placebo-controlled trial assessing changes in bone turnover markers, bone mineral density (BMD), and geometry. Participants: The study population comprised 74 middle-aged obese men with MetS recruited from the general community, of which 66 completed all visits. Mean age of participants was 49.3 ± 6.3 years and mean body mass index was 33.7 ± 3.6 kg/m(2). Intervention: Oral treatment with 1.000 mg RSV (RSVhigh), 150mg RSV (RSVlow), or placebo daily for 16 weeks. Main Outcome Measure: Prespecified primary endpoint was change in bone alkaline phosphatase (BAP). Results: BAP increased dose dependently with RSV (R = 0.471, P < .001), resulting in a significantly greater increase in BAP in the RSVhigh group compared with placebo at all time-points (week 4, 16.4 ± 4.2%, P < .001; week 8, 16.5 ± 4.1%, P < .001; week 16, 15.2 ± 3.7%, P < .001). Lumbar spine trabecular volumetric bone mineral density (LS vBMDtrab) also increased dose dependently with RSV (R = 0.268, P = .036), with a significant increase of 2.6 ± 1.3% in the RSVhigh group compared with placebo (P = .043). In addition, changes in BAP and LS vBMDtrab were positively correlated (R = 0.281, P = .027). No consistent changes were detected in bone density at the hip. Conclusions: Our data suggest that high-dose RSV supplementation positively affects bone, primarily by stimulating formation or mineralization. Future studies of longer duration comprising populations at risk of osteoporosis are needed to confirm these results.
Ornstrup MJ, Harsløf T, Kjær TN, Langdahl BL…
J. Clin. Endocrinol. Metab. Oct 2014
Resveratrol, inositol, vitamin D and K in the prevention of cardiovascular and osteoporotic risk: a novel approach in peri- and postmenopause.
The prevention of cardiovascular and osteoporotic risk is a topic of great importance in the peri- and postmenopausal periods. This paper reviews the role of resveratrol, inositol, vitamin D and K in the prevention of cardiovascular and osteoporotic risk in peri- and post-. The phytoestrogen-like activity of resveratrol has potential clinical implications in the gynecological practice. In particular transresveratrol inhibits low-density lipoprotein oxidation, which is a recognized risk factor for cardiovascular diseases. Resveratrol has also a documented antiplatelet effect and may prevent cardiovascular diseases inhibiting the cardiac fibroblasts proliferation. With regard to bone health, in in vitro studies resveratrol has shown activities in osteoblastic MC3T3-E1 cells. Resveratrol also interacts with vitamin D in promoting bone health. Resveratrol is considered a caloric restriction mimetic and potentially effects factors involved in the metabolic syndrome. Myo-inositol has documented in clinical studies its effectiveness in improving the metabolic syndrome in post menopausal women. Thus the supplementation with inositol and resveratrol may be useful in the prevention of insulin resistance and consequently metabolic syndrome and cardiovascular diseases risk. Finally vitamin K2 effects calcium metabolisms and subjects with higher levels of calcium in the bones tend to have a lower frequency of vascular calcifications and a lower cardiovascular risk. Vitamin K2 also has a key role in the bone homeostasis. A supplement including resveratrol, inositol, vitamin K and vitamin D offers a novel opportunity to the woman in peri- and postmenopause.
Minerva Ginecol Oct 2014
Resveratrol treatment delays growth plate fusion and improves bone growth in female rabbits.
Trans-resveratrol (RES), naturally produced by many plants, has a structure similar to synthetic estrogen diethylstilbestrol, but any effect on bone growth has not yet been clarified. Pre-pubertal ovary-intact New Zealand white rabbits received daily oral administration of either vehicle (control) or RES (200 mg/kg) until growth plate fusion occurred. Bone growth and growth plate size were longitudinally monitored by X-ray imaging, while at the endpoint, bone length was assessed by a digital caliper. In addition, pubertal ovariectomized (OVX) rabbits were treated with vehicle, RES or estradiol cypionate (positive control) for 7 or 10 weeks and fetal rat metatarsal bones were cultured in vitro with RES (0.03 µM-50 µM) and followed for up to 19 days. In ovary-intact rabbits, sixteen-week treatment with RES increased tibiae and vertebrae bone growth and subsequently improved final length. In OVX rabbits, RES delayed fusion of the distal tibia, distal femur and proximal tibia epiphyses and femur length and vertebral bone growth increased when compared with controls. Histomorphometrical analysis showed that RES-treated OVX rabbits had a wider distal femur growth plate, enlarged resting zone, increased number/size of hypertrophic chondrocytes, increased height of the hypertrophic zone, and suppressed chondrocyte expression of VEGF and laminin. In cultured fetal rat metatarsal bones, RES stimulated growth at 0.3 µM while at higher concentrations (10 μM and 50 μM) growth was inhibited. We conclude that RES has the potential to improve longitudinal bone growth. The effect was associated with a delay of growth plate fusion resulting in increased final length. These effects were accompanied by a profound suppression of VEGF and laminin expression suggesting that impairment of growth plate vascularization might be an underlying mechanism.
Karimian E, Tamm C, Chagin AS, Samuelsson K…
PLoS ONE 2013
PMID: 23840780 | Free Full Text
Resveratrol supplementation influences bone properties in the tibia of hindlimb-suspended mature Fisher 344 × Brown Norway male rats.
The deleterious bone effects of mechanical unloading have been suggested to be due to oxidative stress and (or) inflammation. Resveratrol has both antioxidant and anti-inflammatory properties; therefore, the study’s objective was to determine whether providing resveratrol in the low supplementation range for a short duration prevents bone loss during mechanical unloading. Mature (6 months old) Fischer 344 × Brown Norway male rats were hindlimb-suspended (HLS) or kept ambulatory for 14 days. Rats were provided either trans-resveratrol (RES; 12.5 mg/kg body mass per day) or deionized distilled water by oral gavage for 21 days (7 days prior to and during the 14 days of HLS). Bone mass was measured by dual energy X-ray absorptiometry. Bone microstructure was determined by microcomputed tomography. HLS of rats resulted in femur trabecular bone deterioration. Resveratrol supplementation did not attenuate trabecular bone deterioration in HLS rats. Unexpectedly, HLS-RES rats had the lowest tibial bone mineral content (P < 0.05), calcium content and lower cortical thickness (P < 0.05), and increased porosity compared with HLS/control rats. Plasma osteocalcin was also lower (P < 0.04) in HLS/resveratrol rats. There were no significant effects on plasma C-reactive protein, a marker of systemic inflammation, or total antioxidant capacity. However, HLS-RES rats showed a negative relationship (r(2) = 0.69, P = 0.02) between plasma osteocalcin and thiobarbituric acid reactive substances, a marker of lipid peroxidation. Based on the results, resveratrol supplementation of 6-month-old HLS male rats had no bone protective effects and possibly even detrimental bone effects.
Durbin SM, Jackson JR, Ryan MJ, Gigliotti JC…
Appl Physiol Nutr Metab Dec 2012
Resveratrol Supplementation Affects Bone Acquisition and Osteoporosis: Pre-Clinical Evidence Towards Translational Diet Therapy.
Osteoporosis is a major public health issue that is expected to rise as the global population ages. Resveratrol (RES) is a plant polyphenol with various anti-aging properties. RES treatment of bone cells results in protective effects, but dose translation from in vitro studies to clinically relevant doses is limited since bioavailability is not taken into account. The aims of this review is to evaluate in vivo evidence for a role of RES supplementation in promoting bone health to reduced osteoporosis risk and potential mechanisms of action. Due to multiple actions on both osteoblasts and osteoclasts, RES has potential to attenuate bone loss resulting from different etiologies and pathologies. Several animal models have investigated the bone protective effects of RES supplementation. Ovariectomized rodent models of rapid bone loss due to estrogen-deficiency reported that RES supplementation improved bone mass and trabecular bone without stimulating other estrogen-sensitive tissues. RES supplementation prior to age-related bone loss was beneficial. The hindlimb unloaded rat model used to investigate bone loss due to mechanical unloading showed RES supplementation attenuated bone loss in old rats, but had inconsistent bone effects in mature rats. In growing rodents, RES increased longitudinal bone growth, but had no other effects on bone. In the absence of human clinical trials, evidence for a role of RES on bone heath relies on evidence generated by animal studies. A better understanding of efficacy, safety, and molecular mechanisms of RES on bone will contribute to the determination of dietary recommendations and therapies to reduce osteoporosis. This article is part of a Special Issue entitled: Resveratol: Challenges in translating pre-clincial findigns to iproved patient outcomes.
Biochim. Biophys. Acta Oct 2014
Resveratrol mediated modulation of Sirt-1/Runx2 promotes osteogenic differentiation of mesenchymal stem cells: potential role of Runx2 deacetylation.
Osteogenic repair in response to bone injury is characterized by activation and differentiation of mesenchymal stem cells (MSCs) to osteoblasts. This study determined whether activation of Sirt-1 (a NAD(+)-dependent histone deacetylase) by the phytoestrogen resveratrol affects osteogenic differentiation.
Monolayer and high-density cultures of MSCs and pre-osteoblastic cells were treated with an osteogenic induction medium with/without the Sirt-1 inhibitor nicotinamide or/and resveratrol in a concentration dependent manner.
MSCs and pre-osteoblastic cells differentiated to osteoblasts when exposed to osteogenic-induction medium. The osteogenic response was blocked by nicotinamide, resulting in adipogenic differentiation and expression of the adipose transcription regulator PPAR-γ (peroxisome proliferator-activated receptor). However, in nicotinamide-treated cultures, pre-treatment with resveratrol significantly enhanced osteogenesis by increasing expression of Runx2 (bone specific transcription factor) and decreasing expression of PPAR-γ. Activation of Sirt-1 by resveratrol in MSCs increased its binding to PPAR-γ and repressed PPAR-γ activity by involving its cofactor NCoR (nuclear receptor co-repressor). The modulatory effects of resveratrol on nicotinamide-induced expression of PPAR-γ and its cofactor NCoR were found to be mediated, at least in part, by Sirt-1/Runx2 association and deacetylation of Runx2. Finally, knockdown of Sirt-1 by using antisense oligonucleotides downregulated the expression of Sirt-1 protein and abolished the inhibitory effects of resveratrol, namely nicotinamide-induced Sirt-1 suppression and Runx2 acetylation, suggesting that the acetylated content of Runx2 is related to downregulated Sirt-1 expression.
These data support a critical role for Runx2 acetylation/deacetylation during osteogenic differentiation in MSCs in vitro.
Shakibaei M, Shayan P, Busch F, Aldinger C…
PLoS ONE 2012
PMID: 22539994 | Free Full Text
From the introduction:
Resveratrol is a polyphenolic phytoestrogen (trans-3,5, 4′-trihydroxystilbene) found in the skin of red grapes, red vines, various other fruits, peanuts and root extracts of Polygonum cuspidatum . Resveratrol acts as a mixed agonist/antagonist for the estrogen receptors alpha and beta . Through binding to the estrogen receptor, resveratrol is thought to exert beneficial effects on the cardiovascular system and may reverse osteoporosis by a direct stimulatory effect on bone formation in osteoblastic cells . Many of the biological effects of resveratrol have already been demonstrated in the literature; these include cardiovascular protection , anticancer activity  and stimulation of proliferation and osteoblastic differentiation in human and mouse MSCs , . However, its effects on bone are less studied and are particularly relevant to this investigation.
From the discussion:
Resveratrol’s enhancement of osteogenesis was, at least in part regulated by Runx2 with additional contributions by Sirt-1. Resveratrol increases alkaline phosphatase activity in osteoblastic cells  an effect that is blocked by tamoxifen, an estrogen antagonist, suggesting that some of resveratrol’s stimulatory actions may be mediated through the estrogen receptor. Gehm et al. have reported that resveratrol acts as a phytoestrogen (i.e. activating the estrogen receptor) and decreases osteoporosis . Moreover, resveratrol is one of the most potent Sirt-1 activators; through binding to a special binding site it induces a conformational change in Sirt-1, lowering the Km for both the acetylated substrate and NAD, thus resulting in increased enzymatic activity . Sirt-1 facilitates the differentiation of MSCs to osteoblasts by directly regulating factors such as Runx2 and by modulation of nuclear receptor co-repressor NCoR and PPAR-γ.
Potential of resveratrol analogues as antagonists of osteoclasts and promoters of osteoblasts.
The plant phytoalexin resveratrol was previously demonstrated to inhibit the differentiation and bone resorbing activity of osteoclasts, to promote the formation of osteoblasts from mesenchymal precursors in cultures, and inhibit myeloma cell proliferation, when used at high concentrations. In the current study, we screened five structurally modified resveratrol analogues for their ability to modify the differentiation of osteoclasts and osteoblasts and proliferation of myeloma cells. Compared to resveratrol, analogues showed an up to 5,000-fold increased potency to inhibit osteoclast differentiation. To a lesser extent, resveratrol analogues also promoted osteoblast maturation. However, they did not antagonize the proliferation of myeloma cells. The potency of the best-performing candidate in vitro was tested in vivo in an ovariectomy-induced model of osteoporosis, but an effect on bone loss could not be detected. Based on their powerful antiresorptive activity in vitro, resveratrol analogues might be attractive modulators of bone remodeling. However, further studies are required to establish their efficacy in vivo.
Kupisiewicz K, Boissy P, Abdallah BM, Hansen FD…
Calcif. Tissue Int. Nov 2010
PMID: 20842496 | Free Full Text
Effect of catch-up growth by various dietary patterns and resveratrol intervention on bone status.
Catch-up growth (CUG) after food restriction can increase the risks for insulin resistance-related diseases, and to our knowledge, no previous studies have addressed how bone is influenced by CUG when refeeding diet content differs. The objective of this study was to investigate the bone status resulting from CUG induced by varying refeeding dietary patterns, and to assess the potential influencing factors and the effect of resveratrol on bone status during CUG. Experimental rats were randomly divided into five groups: normal chow (NC) group; CUG group (CUG, containing two subgroups, respectively, refeeding with normal chow or high-fat diet); high-fat diet (HF) group; and resveratrol intervention groups (CUGE and HFE). Bone parameters were detected by dual-energy X-ray absorptiometry. Serum concentrations of tumor necrosis factor (TNF)-α, body weight and food intake were also recorded. Our results showed that food restriction induced a significant decrease in bone parameters. Eight-week CUG by normal chow had a greater degree of improvement in bone mineral density than high-fat diet, and even returned to normal level similar to NC. Bone parameters were elevated in varying degrees in the HF group compared with the NC group. In the resveratrol intervention groups, bone parameters significantly increased. Furthermore, bone parameters were inversely related with serum TNF-α concentrations, but showed positive correlation with body weight. In conclusion, the study shows that CUG can partially reverse the deleterious effects of caloric restriction on bone health, especially in the refeeding with normal chow group. Moreover, resveratrol has a protective effect on bone status during the period of CUG. Serum TNF-α levels and body weight also seem to play an important role in regulating bone parameters.
Chen LL, Wang SX, Dai Y, Buckoreelall P…
Exp. Biol. Med. (Maywood) Mar 2012
[Comparative evaluation of the osteoprotective effects of resveratrol and resveratrol/enalapril combination in the treatment of experimental osteoporosis].
The osteoprotective effect of resveratrol and a combination of resveratrol with enalapril has been investigated in white Wistar female rats with experimental osteoporosis. It is established that, in rats after ovariectomy, the endothelial dysfunction of microcirculation vessels of the osteal tissue is developed, resulting in the occurrence of osteoporosis. Resveratrol and the combination of resveratrol with enalapril prevented depression of the microcirculation level in the osteal tissue, thus preventing the thinning of osteal trabecules and preventing their microfractures.
Faĭtel’son AV, Koklina NIu, Gudyrev OS, Dubrovin GM…
Eksp Klin Farmakol 2012