OBJECTIVE: To determine whether resveratrol (Res) can correct osteoporosis induced in a rat model of male hypogonadism. METHODS: Thirty-two rats were randomly divided into 4 groups, 8 in each group; 1) a control sham group: underwent a similar surgical procedure for induction of orchiectomy (ORCD) without ligation of any arteries or veins or removal of the testis and epididymis; 2) a control + Res-treated group (Con+Res): underwent sham surgery similar to the control, but was then treated with Res, as described below; 3) an ORCD-induced group: bilateral ORCD surgery as described above, and 4) a ORCD+Res-treated group: bilateral ORCD surgery followed by Res treatment. Res treatment began 4 weeks after ORCD and continued for 12 weeks. After 12 weeks, bone mineral density (BMD) and bone mineral content (BMC) were measured in the tibia and femur of each rat's right hind leg. Blood levels of bone turnover indicators such as deoxypyridinoline (Dpd), N-telopeptide of type I collagen (NTX I), alkaline phosphatase (ALP), and osteocalcin (OC), as well as receptor activator of nuclear factor kappa B (RANK) and osteoprotegerin (OPG) were assessed. RESULTS: ORCD significantly decreased BMD (P<0.01) and significantly increased bone resorption, manifested by increased RANK. In addition, it inhibited serum levels of OPG and OC. Res treatment after ORCD effectively increased serum levels of bone formation markers such as OPG and OC, compared with testisectomized rats (P<0.05). CONCLUSION Res could ameliorate bone loss induced by male hypogonadism, possible via restoration of the normal balance between RANK and OPG.
Rats ; Male ; Animals ; Bone Density ; Resveratrol/pharmacology* ; Osteoporosis ; Osteoprotegerin/pharmacology* ; Bone Remodeling ; Hypogonadism ; RANK Ligand/pharmacology*

OBJECTIVES: This study aims to determine the effects of low-level laser (LLL) on the expression of interleukin-6 (IL-6), tumor necrosis factor (TNF)-α, osteoprotegerin (OPG), and receptor activator of nuclear factor-κB ligand (RANKL) in human periodontal ligament cells (HPDLCs) stimulated by high glucose; and identify the molecular mechanism of LLL therapy in the regulation of periodontal inflammation and bone remodeling during orthodontic treatment in diabetic patients. METHODS: HPDLCs were cultured in vitro to simulate orthodontic after loading and irradiated with LLL therapy. The cultured cells were randomly divided into four groups: low glucose Dulbecco's modification of Eagle's medium (DMEM)+stress stimulation (group A), high glucose DMEM+stress stimulation (group B), hypoglycemic DMEM+LLL therapy+stress stimulation (group C), and hyperglycemic DMEM+LLL therapy+stress stimulation (group D). Groups C and D were further divided into C1 and D1 (energy density: 3.75 J/cm²) and C2 and D2 (energy density: 5.625 J/cm²). Cells in groups A, B, C, and D were irradiated by LLL before irradiation. At 0, 12, 24, 48, and 72 h, the supernatants of the cell cultures were extracted at regular intervals, and the protein expression levels of IL-6, TNF-α, OPG, and RANKL were detected by enzyme-linked immunosorbent assay. RESULTS: 1) The levels of IL-6 and TNF-α secreted by HPDLCs increased gradually with time under static pressure stimulation. After 12 h, the levels of IL-6 and TNF-α secreted by HPDLCs in group A were significantly higher than those in groups B, C1, and C2 (P<0.05), which in group B were significantly higher than those in groups D1, and D2 (P<0.01). 2) The OPG protein concentration showed an upward trend before 24 h and a downward trend thereafter. The RANKL protein concentration increased, whereas the OPG/RANKL ratio decreased with time. Significant differen-ces in OPG, RANKL, and OPG/RANKL ratio were found among group A and groups B, C1, C2 as well as group B and groups D1, D2 (P<0.05). CONCLUSIONS 1) In the high glucose+stress stimulation environment, the concentrations of IL-6 and TNF-α secreted by HPDLCs increased with time, the expression of OPG decreased, the expression of RANKL increased, and the ratio of OPG/RANKL decreased. As such, high glucose environment can promote bone resorption. After LLL therapy, the levels of IL-6 and TNF-α decreased, indicating that LLL therapy could antagonize the increase in the levels of inflammatory factors induced by high glucose environment and upregulate the expression of OPG in human HPDLCs, downregulation of RANKL expression in HPDLCs resulted in the upregulation of the ratio of OPG/RANKL and reversed the imbalance of bone metabolism induced by high glucose levels. 2) The decrease in inflammatory factors and the regulation of bone metabolism in HPDLCs were enhanced with increasing laser energy density within 3.75-5.625 J/cm². Hence, the ability of LLL therapy to modulate bone remodeling increases with increasing dose.
Humans ; Osteoprotegerin ; Tumor Necrosis Factor-alpha/metabolism* ; Interleukin-6/pharmacology* ; RANK Ligand/pharmacology* ; Periodontal Ligament/metabolism* ; Lasers ; Glucose/pharmacology*

OBJECTIVES: The expression of osteoprotegerin (OPG) and receptor activator of nuclear factor-κB ligand (RANKL) in human periodontal ligament cells (HPDLCs) was investigated by cell culture under continuous static pressure. METHODS: HPDLCs were primarily cultured by tissue explant method and divided into three groups: group A (13-18 years old), group B (19-29 years old), and group C (30-44 years old). CCK-8 was used to detect the proliferation of HPDLCs. The senescence of HPDLCs was detected by senescence-associated β-galactosidase staining. Cells in the three groups were respectively given 0, 1.5, 3, 6, 12, 24, 48, and 72 h of continuous static pressure in vitro. The expression of OPG and RANKL in the supernatant was detected by enzyme-linked immunosorbent assay. RESULTS: After continuous static pressure in vitro for stimulation, the expression of OPG and RANKL changed. The expression of OPG increased with time and age (P<0.01). The expression of RANKL increased with time and decreased with age (P<0.01). The ratio of OPG/RANKL initially decreased, increased with time, and then continued to rise with age (P<0.01). CONCLUSIONS Aging could increase the expression of OPG and the ratio of OPG/RANKL and decrease the expression of RANKL in HPDLCs under continuous static pressure in vitro.
Humans ; Adolescent ; Young Adult ; Adult ; Osteoprotegerin ; RANK Ligand/pharmacology* ; Periodontal Ligament/metabolism* ; Cells, Cultured ; Aging

OBJECTIVE: To investigate the effect of intra-articular berberine injection on the structural remodeling of subchondral bone plate and osteoprotegerin/receptor activator of nuclear factor kappa-B ligand(OPG/RANKL) system expression in rabbits with osteoarthritis(OA). METHODS: Forty 12-month-old male rabbits with an average of(2.73±0.18) kg of body weight, underwent left anterior cruciate ligament transection(ACLT), and were divided into berberine group and placebo groups after operation, 20 rabbits in each group. The berberine group received intra-articular injection of 100 μmol/L berberine 0.3 ml every week for 6 weeks. In placebo group, the same dose of 0.9% sodium chloride injection was injected into the left knee joint cavity every week for 6 weeks. Another 20 12-month-old male rabbits, weighing (2.68±0.18) kg, underwent sham operation on the left knee joint without intra-articular injection intervention (sham operation group). On the last day of the sixth week after operation, three groups of animals were sacrificed to obtain knee joint specimens. The femoral medial condyle samples were obtained for histological evaluation of cartilage and subchondral bone, Mankin scoring system was used to evaluate articular cartilage structure. Image-Pro Plus(IPP) software was used to evaluate subchondral bone plate bone volume(BV), bone volume/total volume(BV/TV), trabecular circumference(TC), mean trabecular thickness (Tb.Th). Real-time quantitative reverse transcription polymerization Enzyme chain reaction(reverse transcription-polymerase chain reaction, RT-PCR) was used to detect the mRNA expression levels of OPG and RANKL in subchondral bone tissue at 6 weeks after operation. RESULTS: The cartilage structure evaluation showed that the surface of cartilage tissue in the sham operation group was smooth and flat, and the safranin coloration was full in the full thickness of the cartilage;the cartilage tissue in the berberine group showed uneven surface layer, and the staining of safranin O was mildly decreased;the surface layer fibrosis was seen in placebo group, Safranin O faded significantly. The Mankin score in the berberine group was lower than that in placebo group(P<0.01), but higher than that in sham operation group(P<0.01). The structural evaluation of subchondral bone plate showed that the trabecular bone in sham-operated group was densely arranged;after berberine intervention, the trabeculae were closely arranged;the subchondral bone trabeculae in placebo group were relatively sparse, and the distance between trabeculae was wider. Subchondral bone plate IPP software evaluation showed that BV, BV/TV, TC, Tb.Th in berberine group were higher than those in placebo group(P<0.01), BV, BV/TV, TC, Tb.Th in berberine group were higher than those in placebo group(P<0.01), while lower than the sham operation group (P<0.01). PCR test results showed that the expression of OPG mRNA in the berberine group was significantly higher than that in placebo group(P<0.01), and OPG mRNA in the berberine group was lower than that in sham operation group (P<0.01). There was no significant difference in mRNA expression of RANKL among three groups(P>0.05);the ratio of OPG/RANKL in berberine group was higher than that in placebo group(P<0.01), but lower than that in sham operation group(P<0.01). CONCLUSION Intra-articular injection of berberine can effectively inhibit the resorption of subchondral bone in the early stage of OA and delay the development of the disease. The specific mechanism may be that berberine maintains the balance of OPG/RANKL system by up-regulating the expression of OPG gene in subchondral bone.
Animals ; Berberine/therapeutic use* ; Bone Density Conservation Agents/therapeutic use* ; Bone Plates ; Cartilage, Articular ; Humans ; Ligands ; Male ; NF-kappa B/metabolism* ; Osteoarthritis/metabolism* ; Osteoprotegerin/metabolism* ; RNA, Messenger/therapeutic use* ; Rabbits

OBJECTIVES: This study aimed to explore the changes in the expression of the characteristic transcription factor retinoid related orphan receptor γt (RORγt) and the cytokine interleukin-17 (IL-17) of T helper cell 17 (Th17) in the pressure side of the periodontal tissue of rats under different orthodontic forces. Their effects on the expression of osteoprotegerin (OPG) and the quantity of osteoclast (OC) were also explored. The role of Th17 cell in alveolar bone remodeling under different forces was preliminarily investigated. METHODS: A total of 108 rats were chosen and randomly divided into three groups. Mesial forces of 0, 50, and 100 g were loaded on the maxillary first molar in the three groups. The rats were executed at 0, 1, 3, 5, 7, and 14 days. The expression of RORγt mRNA was quantified by real-time quantitative polymerase chain reaction. The expression of IL-17 protein was quantified by enzyme linked immunosorbent assay. The expression levels of RORγt and OPG proteins were quantified, and the quantity of OC was counted via immunohistochemistry. RESULTS: The expression levels of RORγt and IL-17 and the quantity of OC increased first and then decreased in the 50 and 100 g groups, and the peak values of the two groups were on days 5 and 7, respectively. The expression levels in the 50 g group basically recovered to normal level on day 14, while that in the 100 g group remained at a high level. The expression levels in the 50 g group were higher than those in the 0 g group and lower than those in the 100 g group. The expression of OPG in the 50 g group decreased first, then increased, and finally decreased. It basically recovered to normal level on day 14. The expression of OPG in the 100 g group decreased first and then increased. It remained at a high level on day 14. The expression in the 50 g group was significantly higher than that in the 0 g group on day 7, while the expression in the 100 g group was significantly higher than that in the 0 g group on day 14. CONCLUSIONS RORγt, IL-17, and OPG were expressed regularly over time under different orthodontic forces, indicating that Th17 participated in the process of bone resorption on the pressure side of periodontal tissue by secreting IL-17.
Animals ; Bone Resorption ; Cytokines ; Interleukin-17 ; Molar ; Nuclear Receptor Subfamily 1, Group F, Member 3 ; Osteoclasts ; Osteoprotegerin ; Rats ; Th17 Cells ; Tooth Movement Techniques

Bone invasion by oral cancer is a common clinical problem, which affects the choice of treatment and predicts a poor prognosis. Unfortunately, the molecular mechanism of this phenomenon has not been fully elucidated. Current studies have revealed that oral cancer cells modulate the formation and function of osteoclasts through the expression of a series of signal molecules. Many signal pathways are involved in this process, of which receptor activator of nuclear factor-κB ligand/receptor activator of nuclear factor-κB/osteoprotegerin signaling pathway attracted much attention. In this review, we introduce recent progress in molecular mechanisms of bone invasion by oral cancer.
Bone Resorption ; Bone and Bones ; Humans ; Mouth Neoplasms ; Osteoclasts ; Osteoprotegerin ; RANK Ligand ; Receptor Activator of Nuclear Factor-kappa B

BACKGROUND: Obstructive sleep apnea-hypopnea syndrome (OSAHS) is associated with a higher prevalence of osteoporosis. However, the underlying mechanisms linking OSAHS with bone loss are still unclear. The aim of this study was to investigate the changes of receptor activator of nuclear factor-κB ligand (RANKL, an osteoclastogenesis-promoting factor) and osteoprotegerin (OPG, the decoy receptor for RANKL), oxidative stress and bone metabolism markers in OSAHS, in order to understand the potential mechanisms underlying bone loss in OSAHS patients. METHODS: Forty-eight male patients with OSAHS, confirmed by polysomnography (PSG) study, were enrolled. Twenty male subjects who were confirmed as not having OSAHS served as the controls. The subjects' bone mineral density (BMD) was assessed in lumbar spine and femoral neck using dual-energy X-ray absorptiometry (DXA). Blood samples were collected from all subjects for measurement of RANKL, OPG, the bone formation marker bone-specific alkaline phosphatase (BAP), the bone resorption marker tartrate-resistant acid phosphatase 5b (TRAP-5b), and total antioxidant capacity (TAOC). RESULTS: The BMD and the T-score of the femoral neck and the lumbar spine were significantly lower in OSAHS patients as compared to the control group (P < 0.05). The serum level of BAP was significantly decreased in the OSAHS group (15.62 ± 5.20 μg/L) as compared to the control group (18.83 ± 5.50 μg/L, t = -2.235, P < 0.05), while the levels of TRAP-5b did not differ between the two groups (t = -1.447, P > 0.05). The serum level of OPG and the OPG/RANKL ratio were lower in the OSAHS group compared to the control group (both P < 0.05). TAOC level was also decreased significantly in the OSAHS group (P < 0.05). Correlation analysis showed that the TAOC level was positively correlated with BAP in the OSAHS group (r = 0.248, P = 0.04), but there were no correlations between TAOC and the BMD or the T-scores. The correlations between the level of OPG (or the OPG/RANKL ratio) and BMD or TAOC did not reach significance. CONCLUSION In OSAHS patients, lower levels of TAOC were associated with decreased bone formation, suggesting a role of oxidative stress in bone loss, while the role of OPG/RANKL imbalance in bone metabolism in OSAHS needs further evaluation.
Absorptiometry, Photon ; Adolescent ; Adult ; Bone Density ; physiology ; Female ; Humans ; Male ; Middle Aged ; NF-kappa B ; blood ; Osteogenesis ; physiology ; Osteoporosis ; blood ; Osteoprotegerin ; blood ; Oxidative Stress ; physiology ; Polysomnography ; Sleep Apnea, Obstructive ; blood ; Young Adult

BACKGROUND: Serum myostatin levels are increased according to renal function decline and myostatin may be a main mediator of chronic kidney disease–related sarcopenia. A previous study reported that serum myostatin level was negatively associated with abdominal aortic calcification (AAC) in older males. The aim of this study was to assess the association between serum myostatin level and AAC among dialysis patients of both sexes. In addition, we analyzed the relationship between serum myostatin level, muscle mass, and bone mineral density (BMD).METHODS: In this cross-sectional study, we evaluated AAC in the lateral lumbar spine using plain radiography and BMD in 71 patients undergoing dialysis. We classified patients into two groups according to the median value of myostatin as follows: those with high myostatin levels (≥ 5.0 ng/mL) and those with low myostatin levels (< 5.0 ng/mL).RESULTS: The proportion of patients with an AAC score of five points or more was higher among those with low myostatin levels. Myostatin level was negatively associated with AAC scores on plain radiography and had a positive association with skeletal muscle mass and T-scores for BMD measured at the total hip and femur neck. Lower myostatin levels were independently associated with higher AAC scores following adjustment for age, sex, diabetes mellitus, dialysis vintage, dialysis modality, and osteoprotegerin level.CONCLUSION: Lower serum myostatin levels were associated with higher AAC scores, lower muscle mass, and lower BMD in dialysis patients. Further, prospective studies and those with larger cohorts are necessary to validate these findings.
Bone Density ; Cohort Studies ; Cross-Sectional Studies ; Diabetes Mellitus ; Dialysis ; Femur Neck ; Hip ; Humans ; Kidney ; Male ; Muscle, Skeletal ; Myostatin ; Osteoprotegerin ; Prospective Studies ; Radiography ; Sarcopenia ; Spine ; Vascular Calcification

OBJECTIVE: To explore the polymorphisms of T149C and T950C gene in osteoprotectin (OPG) promoter sites and the levels of serum OPG and soluble nuclear factor-ΚB receptor activator ligand (sRANKL) and the incidence of coronary heart disease (CHD). METHODS: 528 patients in Tianjin suspected of CHD and underwent coronary angiography (CAG) who admitted to the department of cardiology of Tianjin Chest Hospital from April 2017 to December 2018 were enrolled. According to the CAG results, they were divided into two groups: CHD group (n = 302) and non-CHD group (n = 226). The gender, age, history of hypertension, family history of CHD, diabetes, levels of blood lipid parameters in serum and other clinical data of patients were recorded. The levels of serum OPG and sRANKL were measured by enzyme-linked immunosorbent assay (ELISA). T149C and T950C gene polymorphisms were analyzed by polymerase chain reaction-restriction endonuclease fragment length polymorphism (PCR-RFLP) methods. Hardy-Weinberg genetic balance test was performed for alleles. Binomial classification multivariate non-conditional Logistic regression method was used to analyze the relationship between T149C and T950C gene polymorphisms, serum levels of OPG and sRANKL and CHD. RESULTS: All patients were enrolled in the final analysis. The serum level of OPG in CHD group was significantly higher than that in non-CHD group (μg/L: 1.76±0.49 vs. 1.47±0.29, P < 0.01), the serum level of sRANKL was significantly lower than that in non-CHD group (ng/L: 342.14±121.38 vs. 376.63±108.66, P < 0.05). Logistic regression analysis showed that after adjusting for age, gender, blood lipid parameters, diabetes and other factors, the increase in serum OPG level was an independent risk factor for CHD [odds ratio (OR) = 1.995, 95% confidence interval (95%CI) = 1.935-2.066, P = 0.012]. PCR-RFLP results showed that TT, TC and CC genotypes were found in T149C and T950C of OPG promoter. According to Hardy-Weinberg equilibrium test, the polymorphisms of OPG T149C and T950C accorded with Hardy-Weinberg law, achieving genetic balance with representative of the population. The frequencies of TT, TC, CC and alleles T and C in T149C genotypes of non-CHD group were 53.5%, 42.9%, 3.6%, 75.0% and 25.0%, respectively, and they were 43.1%, 50.3%, 6.6%, 68.2% and 31.8%, respectively in CHD group. There were statistically significant differences in genotype and allele frequencies between the two groups (all P < 0.05). It was shown by Logistic regression analysis that the risk of CHD in TC+CC genotype of T149C was 1.86 of TT genotype (OR = 1.86, 95%CI = 1.24-2.78, P = 0.003). It was suggested that C allele might be a susceptible gene for CHD. In non-CHD group, the frequencies of TT, TC, CC, and alleles T and C in T950C genotypes were 39.8%, 46.5%, 13.7%, 63.1% and 36.9%, respectively. They were 39.4%, 43.4%, 17.2%, 61.1% and 38.9%, respectively in CHD group. There were no significant differences in genotype and allele frequencies between the two groups (all P > 0.05). Logistic regression analysis showed that TC+CC genotype of T950C was not related with CHD. CONCLUSIONS The increased level of serum OPG was closely related with CHD and could be used as a risk factor for CHD. The cases carried OPG T149C TC+CC genotype might have the risk suffering CHD. C allele is might be a susceptible gene.
China/epidemiology* ; Coronary Disease/epidemiology* ; Female ; Humans ; Male ; Osteoprotegerin/genetics* ; Polymorphism, Genetic ; Promoter Regions, Genetic/genetics* ; Risk Factors

The interplay between mechanoresponses and a broad range of fundamental biological processes, such as cell cycle progression, growth and differentiation, has been extensively investigated. However, metabolic regulation in mechanobiology remains largely unexplored. Here, we identified glucose transporter 1 (GLUT1)-the primary glucose transporter in various cells-as a novel mechanosensitive gene in orthodontic tooth movement (OTM). Using an in vivo rat OTM model, we demonstrated the specific induction of Glut1 proteins on the compressive side of a physically strained periodontal ligament. This transcriptional activation could be recapitulated in in vitro cultured human periodontal ligament cells (PDLCs), showing a time- and dose-dependent mechanoresponse. Importantly, application of GLUT1 specific inhibitor WZB117 greatly suppressed the efficiency of orthodontic tooth movement in a mouse OTM model, and this reduction was associated with a decline in osteoclastic activities. A mechanistic study suggested that GLUT1 inhibition affected the receptor activator for nuclear factor-κ B Ligand (RANKL)/osteoprotegerin (OPG) system by impairing compressive force-mediated RANKL upregulation. Consistently, pretreatment of PDLCs with WZB117 severely impeded the osteoclastic differentiation of co-cultured RAW264.7 cells. Further biochemical analysis indicated mutual regulation between GLUT1 and the MEK/ERK cascade to relay potential communication between glucose uptake and mechanical stress response. Together, these cross-species experiments revealed the transcriptional activation of GLUT1 as a novel and conserved linkage between metabolism and bone remodelling.
Animals ; Biomechanical Phenomena ; Blotting, Western ; Bone Remodeling ; drug effects ; Cells, Cultured ; Glucose Transporter Type 1 ; antagonists & inhibitors ; genetics ; Humans ; Hydroxybenzoates ; pharmacology ; Immunohistochemistry ; MAP Kinase Signaling System ; drug effects ; Mice ; Mice, Inbred C57BL ; Osteoprotegerin ; metabolism ; Periodontal Ligament ; cytology ; RANK Ligand ; metabolism ; Rats ; Rats, Sprague-Dawley ; Reverse Transcriptase Polymerase Chain Reaction ; Tooth Movement Techniques ; Transcriptional Activation