Effect of Body Surface Area on Severe Osteoporotic Fractures: A Study of Osteoporosis in Changsha China.

Clinical vertebral fractures and femoral neck fractures are severe osteoporotic fractures that increase morbidity and mortality. Anthropometric variables are associated with an increased risk of osteoporotic fractures, but it is not clear whether body surface area (BSA) has an effect on clinically severe osteoporotic fractures. The study included total of 3,694 cases of clinical vertebral fractures and femoral neck fractures (2,670 females and 1,024 males) and 3,694 controls without fractures who were matched with the cases by sex and age. There was a significant positive correlation between BSA and bone mineral density (BMD) in female and male fracture patients (females: r = 0.430-0.471, P < 0.001; males: r = 0.338-0.414, P < 0.001). There was a significant systematic increase in BMD in both genders at various skeletal sites, grouped by BSA quartile. The osteoporosis rates of the lumbar spine (97.9%), femoral neck (92.4%) and total hip (87.1%) in the female Q1 group were significantly higher than those in the Q4 group (P < 0.001), which were 80.0%, 57.9% and 36.9%, respectively, in the Q4 group; the osteoporosis rates of the lumbar spine, femoral neck, and total hip were 53.9%, 59.4%, and 36.3% in the male Q1 group, and 15.2%, 21.9%, and 7.03% in the Q4 group, which were significantly lower than those in the Q1 group (P < 0.001). In age-adjusted Cox regression models, the risk of fracture in the remaining three groups (Q2, Q3, and Q4) for weight, BMI, and BSA for both genders, compared with the highest quartile (Q1 by descending quartile stratification) were significantly higher. In models adjusted for age and BMD, only men in the BSA Q3 (HR = 1.55, 95% CI = 1.09-2.19) and BSA Q4 groups (HR = 1.41, 95% CI = 1.05-1.87) had significantly higher fracture risks. In models adjusted for age, height, weight, BMI, and BSA, low BMD was the greatest fracture risks for both sexes. Our results showed that BSA was closely related to BMD, prevalence of osteoporosis, and fracture risk, and that a decline in BSA may be a new potential risk factor for osteoporotic fractures in Chinese men.

Oestrogen Inhibits Arterial Calcification by Promoting Autophagy.

Arterial calcification is a major complication of cardiovascular disease. Oestrogen replacement therapy in postmenopausal women is associated with lower levels of coronary artery calcification, but its mechanism of action remains unclear. Here, we show that oestrogen inhibits the osteoblastic differentiation of vascular smooth muscle cells (VSMCs) in vitro and arterial calcification in vivo by promoting autophagy. Through electron microscopy, GFP-LC3 redistribution, and immunofluorescence analyses as well as measurement of the expression of the autophagosome marker light-chain I/II (LC3I/II) and autophagy protein 5 (Atg5), we show that autophagy is increased in VSMCs by oestrogen in vitro and in vivo. The inhibitory effect of oestrogen on arterial calcification was counteracted by 3-methyladenine (3MA) or knockdown of Atg5 and was increased by rapamycin. Furthermore, the inhibitory effect of oestrogen on arterial calcification and the degree of autophagy induced by oestrogen were blocked by a nonselective oestrogen receptor (ER) antagonist (ICI 182780), a selective oestrogen receptor alpha (ERα) antagonist (MPP), and ERα-specific siRNA. Our data indicate that oestrogen inhibits the osteoblastic differentiation of VSMCs by promoting autophagy through the ERα signalling pathway in vitro and arterial calcification in vivo by increasing autophagy. Our findings provide new insights into the mechanism by which oestrogen contributes to vascular calcification in vitro and in vivo.

Gender differences in a reference database of age-related femoral neck geometric parameters for Chinese population and their association with femoral neck fractures.

Femoral neck geometric parameters (FNGPs) are closely related to the strength of the femoral neck and the risk of fragility fractures. No reference database is available for FNGPs for Chinese population, and gender-related differences in FNGPs as well as their association with the risk of femoral neck fractures are unknown. This investigation aimed to set up reference databases for FNGPs, understand gender-related differences in FNGPs, and examine the association between FNGPs and the risk of osteoporotic fractures of the femoral neck. This study included 5268 females and 2156 males (aged 15-91years) from Chinese population. A total of 384 patients (282 females and 102 males) had sustained femoral neck fractures; 384 age- and sex-matched individuals without any fractures served as controls. Femoral neck DXA images were used to measure bone mineral density (BMD) and eight FNGPs. Our results showed that the age-related trends of FNGPs were fitted with the best goodness-of-fit by applying the cubic regression model. The trends shown by FNGPs were significantly different between male and female subjects, and the fitting curves were significantly higher in male subjects. After adjustments were made for age, height, weight, and body mass index, Cox regression analysis showed that changes in all FNGPs were related to increased hazard ratios (HRs) of femoral neck fractures. After further adjustment was made for BMD of the femoral neck, the HRs related to a cortical thickness (CT) decrease and buckling ratio (BR) increase in females went up by 3.35-folds (95% CI: 2.75-4.07) and 1.86-folds (95% CI: 1.33-2.60), respectively. In males, the HRs related to the decrease in CT and cross-sectional area (CSA) increased by 3.21-folds (95% CI: 2.32-4.45) and 1.88-folds (95% CI: 1.03-3.44), respectively. In conclusions, the reference databases of FNGPs established in this study will assist in the evaluation and prediction of femoral neck fracture risk in the clinic. The decrease in CT and increase in BR of the femoral neck were independent risk factors for osteoporotic fractures of the femoral neck in females from mainland China, while a decrease in CT and CSA were risk factors in male.

Epidemiology and management of osteoporosis in the People's Republic of China: current perspectives.

With the progressive aging of the population, osteoporosis has gradually grown into a global health problem for men and women aged 50 years and older because of its consequences in terms of disabilities and fragility fractures. This is especially true in the People's Republic of China, which has the largest population and an increasing proportion of elderly people, as osteoporosis has become a serious challenge to the Chinese government, society, and family. Apart from the fact that all osteoporotic fractures can increase the patient's morbidity, they can also result in fractures of the hip and vertebrae, which are associated with a significantly higher mortality. The cost of osteoporotic fractures, moreover, is a heavy burden on families, society, and even the country, which is likely to increase in the future due, in part, to the improvement in average life expectancy. Therefore, understanding the epidemiology of osteoporosis is essential and is significant for developing strategies to help reduce this problem. In this review, we will summarize the epidemiology of osteoporosis in the People's Republic of China, including the epidemiology of osteoporotic fractures, focusing on preventive methods and the management of osteoporosis, which consist of basic measures and pharmacological treatments.

Age-related bone turnover markers and osteoporotic risk in native Chinese women.

BACKGROUND: The rate of bone turnover is closely related to osteoporosis risk. We investigated the correlation between bone turnover markers and BMD at various skeletal sites in healthy native Chinese women, and to study the effect of changes in the levels of bone turnover markers on the risk of osteoporosis. METHODS: A cross-section study of 891 healthy Chinese women aged 20-80 years was conducted. The levels of serum osteocalcin (OC), bone-specific alkaline phosphatase (BAP), serum cross-linked N-terminal telopeptides of type I collagen (sNTX), cross-linked C-terminal telopeptides of type I collagen (sCTX), urinary NTX (uNTX), urinary CTX (uCTX) and total urinary deoxypyridinoline (uDPD) were determined. BMD at the posteroanterior spine and the hip was measured using DXA. RESULTS: Pearson's correlation coefficient found significant negative correlation between bone turnover marker and BMD T-score at different skeletal sites (r = -0.08 to -0.52, all P = 0.038-0.000). After adjustments for age and body mass index, the partial correlation coefficients between the OC, BAP, sNTX, sCTX and uCTX, and the T-scores at various skeletal sites were still significant. After adjustment of height and weight, the correlation coefficients between most BTMs and PA lumbar spine BMD were also significant. Multiple linear regression analysis showed that bone turnover markers were negative determinants of T-scores. BAP and OC accounted for 33.1% and 7.8% of the variations in the T-scores of the PA spine, respectively. Serum OC, BAP, uDPD, and sNTX accounted for 0.4-21.9% of the variations in the femoral neck and total hip T-scores. The bone turnover marker levels were grouped as per quartile intervals, and the T-scores, osteoporosis prevalence and risk were found to markedly and increase with increase in bone turnover marker levels. CONCLUSIONS: This study clarified the relationship between bone turnover markers and osteoporosis risk in native Chinese women. Bone turnover marker levels were found to be important determinants of BMD T-scores. Furthermore, osteoporotic risk significantly increased with increase in the levels of bone turnover markers.

Relationships between age-related biochemical markers of bone turnover and OPG, TGF-ß1 and TGF-ß2 in native Chinese women.

Osteoprotegerin (OPG), transforming growth factor-ß1 (TGF-ß1) and TGF-ß2 are cytokines closely associated with bone metabolism. However, their association with bone turnover markers in native Chinese women remains unknown. The study aims to investigate the relationship between bone metabolism related cytokines including OPG, TGF-ß1, TGF-ß2 and bone turnover markers in native Chinese women. The cross-sectional study was conducted on 691 healthy Chinese women (20-80 years old). Levels of OPG, TGF-ß1, TGF-ß2, serum bone-specific alkaline phosphatase (BAP), osteocalcin (OC), cross-linked N-terminal telopeptides of type I collagen (sNTX), cross-linked C-terminal telopeptides of type I collagen (sCTX), urinary NTX (uNTX), urinary CTX (uCTX) and total urinary deoxypyridinoline (uDPD) were determined. The present study showed that OPG and TGF-ß2 had positive correlation with BAP, OC, uNTX, uCTX and uDPD, while TGF-ß1 showed negative correlation with BAP, OC, sCTX, uNTX and uCTX, and most of the coefficients of partial correlation remained significant after adjustments for age and body mass index (BMI). Multiple linear regression stepwise analysis showed that OPG and TGF-ß2 were positive determinative factors for BAP, sCTX, uNTX and uCTX, which could explain 0.6-16.6% of the variation in these markers. TGF-ß1 was a negative determinative factor for BAP, OC, sCTX and uCTX, which could explain 0.7-7.3% of the variation in these markers. This study suggested that measuring bone turnover indicators and serum cytokines simultaneously might help evaluating changes in bone turnover rate caused by aging or menopause in women.

[Relationship of age-related levels of serum sex hormones with bone mineral density decreasing rate in women].

OBJECTIVE: To explore the relationship between the changes of estrogen, follicle-stimulating hormone (FSH) and luteinizing hormone (LH) levels and bone mineral density (BMD) decreasing rate (BDR) at different skeletal regions and examine the effects of hormones levels on BDR. METHODS: An age cross-sectional study was conducted in 694 healthy adult women excluded from diseases and drugs affecting bone metabolism. Their age range was 20-80 years. The serum concentrations of FSH, LH and estradiol (E2) were measured with radioimmunoassay. And BDR was measured with a DXA fan-beam bone densitometer at various skeletal regions including lumbar spine, left hip and left forearm. RESULTS: The serum levels of FSH (r = -0.597 to -0.479, all P < 0.01) and LH r = -0.452 to -0.283, all P < 0.01) were significantly negatively correlated with BDR at various skeletal regions. Meanwhile, the serum level of E2 only had slightly positive correlation with hip and distal forearm (r = 0.077 to 0.122, all P < 0.05). After adjusting age and body mass index (BMI), serum FSH still had markedly negative correlation with BDR at various skeletal regions. However, the correlation coefficients became weak. Multiple line regression stepwise analysis revealed that serum FSH was a negative determinant factor of BDR at various skeletal regions: 20%-32% changes in BDR of various skeletal regions were determined by FSH, while LH only produced very small negative effects (0.6%-0.8%) on BDR of lumbar spine. Serum E2 seemed to be a positive determinant factor of skeletal regions and 2.5%-5.4% changes in BDR were determined by E2. The effects of serum FSH on BDR were approximately 3.8-12.8 folds than those of serum E2. CONCLUSIONS: BDR is correlated with increased FSH in women. The most critical factor for aging-related BDR is FSH in women while a decreased level of estrogen may be secondary.

Relationship between Serum Levels of OPG and TGF- ß with Decreasing Rate of BMD in Native Chinese Women.

The objective of this study was to investigate the relationship between serum levels of OPG, TGF- ß 1, and TGF- ß 2 and BMD decrease rate (BDR) in native Chinese women. This cross-sectional study was performed on 465 healthy native Chinese women aged 35-80 years. Serum levels of OPG, TGF- ß 1, and TGF- ß 2 were determined. BDR was measured by DXA at the posteroanterior spine, hip, and distal forearm. At all skeletal sites tested, there was a negative correlation between BDR and serum levels of both OPG (r = -0.122 to -0.230, all P = 0.007-0.000) and TGF- ß 2 (r = -0.100 to -0.173, all P = 0.029-0.000) and a positive correlation between BDR and serum TGF- ß 1 (r = 0.245 - 0.365, all P = 0.000). After adjustment for age and BMI, there were no statistically significant correlations between serum levels of OPG or TGF- ß 2 and BDR. However, statistically significant correlations between serum TGF- ß 1 and BDR at the lumbar spine and ultradistal forearm remained. Multiple linear regression stepwise analysis showed that serum OPG could explain 1.4-3.7% of BDR variation. Serum TGF- ß 1 was a positive determinant of BDR and could explain 5.3-13.3% of BDR variation.

Early bone mineral density decrease is associated with FSH and LH, not estrogen.

BACKGROUND: It remains unclear whether gonadotropins or estrogen is responsible for early bone mineral density (BMD) decrease in Chinese women. METHODS: A cross-sectional study was conducted on 368 healthy adult women, aged 35-60 years. We measured BMD, calculated BMD decrease rates (BDRs) and assessed serum follicle-stimulating hormone (FSH), luteinizing hormone (LH) and estradiol (E(2)) levels. RESULTS: BDR was significantly negatively correlated with serum FSH (r=-0.429 to -0.622, all p=0.000) and LH (r=-0.359 to -0.526, all p=0.000). After adjustment for age and body mass index, the negative correlations of serum FSH and LH with BDR persisted, but there was no overall correlation between serum E(2) and BDR. Multiple linear stepwise regression analysis suggested that serum FSH is a negative determinant of BDR. Serum E(2) seems to be a positive determinant of BDR in a few parts of the skeleton. CONCLUSIONS: The decrease of BMD during the menopause is associated with FSH and LH levels, rather than E(2) in Chinese women.

The relationship between bone turnover markers and BMD decreasing rates in Chinese middle-aged women.

BACKGROUND: The relationship between bone turnover markers (BTMs) and BMD decreasing rate (BDR) in Chinese women is unclear. Wu investigated the relationship between (BTMs) and BDR at various skeletal sites in Chinese middle-aged women. METHODS: A cross-section study of 555 healthy Chinese women over 35-60years of age. BMD at posteroanterior spine, the left hip, and the left forearm were measured with a DXA. Levels of serum osteocalcin (OC), bone-specific alkaline phosphatase (BAP), cross-linked N-terminal telopeptides of type I collagen (sNTX) and total urinary deoxypyridinoline (uDPD) were determined. RESULTS: BDR at various skeletal sites had significant negative correlation with serum OC(r=-0.395 to -0.530), BAP(r=-0.297 to -0.486), and sNTX(r=-0.207 to -0.272). After adjustment of age and weight, serum OC, BAP, and sNTX rather than total uDPD still exhibited significant correlations with BDR. Stepwise regression analyses showed that, serum OC and BAP were the significantly negative determinants of BDR. Between 4.7-27.7% and 1.2-16.1% of the changes in BDR were determined by serum OC and BAP, respectively. However, sNTX and total uDPD had no significant effect on BDR at various skeletal sites. CONCLUSIONS: This study indicated the correlation between BTMs and early-stage BDR in Chinese middle-aged women and suggested that serum OC and BAP, rather than sNTX and total uDPD, are the key determining factors of early BMD decreases.

The relationship between the levels of gonadotropic hormones and OPG, leptin, TGF-beta1 and TGF-beta2 in Chinese adult women.

BACKGROUND: The relationship between the levels of gonadotropic hormones and bone metabolism-related cytokines in Chinese women is unclear. We investigated the relationship between FSH and LH and OPG, leptin, TGF-beta1, and TGF-beta2 in Chinese women. METHODS: A cross-sectional study of 694 Chinese women, aged 20 to 82y was conducted. Levels of serum FSH, LH, OPG, leptin, TGF-beta1, and TGF-beta2 were determined. RESULTS: In premenopausal females, serum follicle-stimulating hormone (FSH) and luteinizing hormone (LH) levels seemly showed no correlation with the cytokine levels. In perimenopausal females, serum FSH and LH levels showed significant positive correlation with osteoprotegerin (OPG) and transforming growth factor-beta2 (TGF-beta2) levels (r=0.286 to 0.405, all P=0.000), whereas they showed negative correlation with TGF-beta1 levels (r=-0.413 and -0.354, all P=0.000). In postmenopausal females, FSH and LH levels showed positive correlation with OPG levels (r=0.247 and 0.241, all P=0.000), negative correlation with leptin and TGF-beta1 levels (r=-0.234 to -0.319, all P=0.000), and no correlation with TGF-beta2 levels. Multiple linear regression stepwise analysis revealed the following results. In premenopausal females, 2.0% and 1.5% of the changes in LH could be explained by OPG and leptin, respectively, while 1.9% of the changes in OPG could be explained by LH. In perimenopausal females, the determinants of OPG and TGF-beta1 on FSH were 10.9% and 17.0%, respectively, and the determinants of OPG, TGF-beta1 and TGF-beta2 on LH were 4.5%, 4.9% and 16.4%, respectively. The determinants of FSH and LH on OPG were 14.5% and 2.5%, respectively. The determinant of FSH on TGF-beta1 was 4.5%, while the determinant of LH on TGF-beta2 was 16.4%. In postmenopausal females, the determinants of leptin and OPG on FSH were 10.2% and 2.8%, respectively, and the determinants of OPG and TGF-beta1 on LH were 5.8% and 2.3%, respectively. The determinant of FSH on OPG, leptin and TGF-beta1 were 6.1%, 3.4% and 9.2%. CONCLUSIONS: These results indicate that age-related gonadotropic hormone levels are associated with changes in OPG, TGF-beta1, TGF-beta2 and leptin, and change with menopausal status.

L-carnitine and taurine synergistically inhibit the proliferation and osteoblastic differentiation of vascular smooth muscle cells.

AIM: To investigate the synergistic action of L-carnitine (LC) and taurine (TAU) on the proliferation and osteoblastic differentiation of vascular smooth muscle cells (VSMCs). METHODS: DNA and protein synthesis of VSMCs were assessed using scintillation counting. Alkaline phosphatase (ALP) activity and calcium content were determined to investigate the effects of LC and TAU on the osteoblastic differentiation and mineralization of VSMCs. TAU uptake by VSMCs was assayed. RNA interference was used to down-regulate the expression of the TAU transporter (TAUT) in rat VSMCs. RESULTS: LC and TAU synergistically inhibited the proliferation and beta-glycerophosphate (beta-GP)-induced osteoblastic differentiation of VSMCs as evidenced by the decreased [(3)H]thymidine incorporation, ALP activity and calcium deposition. Furthermore, LC stimulated the TAU uptake and TAUT expression in VSMCs. Suppression of TAUT with short hairpin RNA (shRNA) abolished the synergistic action of LC and TAU in VSMCs. CONCLUSION: The synergistic inhibitory action of LC and TAU on the proliferation and osteoblastic differentiation of VSMCs is attributable to the up-regulation of TAUT expression and TAU uptake by LC.

Taurine restores Axl/Gas6 expression in vascular smooth muscle cell calcification model.

Our previous studies demonstrated that taurine inhibits osteoblastic differentiation of vascular smooth muscular cells (VSMCs) via the mitogen-activated protein kinase/extracellular signal-regulated kinase (MAPK/ERK) signaling pathway, but the underlying mechanism is not elucidated. The tyrosine kinase receptor Axl and its ligand growth arrest-specific protein 6 (Gas6) are expressed in VSMCs. Axl/Gas6 signaling system is known to inhibit VSMCs calcification. We herein showed that taurine partially restored Axl and Gas6 expression in beta-glycerophosphate (beta-GP)-induced VSMC calcification model. Taurine also induced activation of ERK, but not other two MAPKs including c-jun N-terminal Kinase (JNK) and p38 in VSMCs. Either knockdown of the taurine transporter (TAUT) or treatment with the ERK-specific inhibitor PD98059 blocked the activation of ERK by taurine and abolished taurine-induced Axl/Gas6 expression and calcium deposition reduction in beta-GP-induced VSMC calcification model. These results demonstrate for the first time that taurine stimulates expression of Axl and Gas6 via TAUT/ERK signaling pathway in beta-GP-induced VSMC calcification model.

Relationship between age-related serum concentrations of TGF-beta1 and TGF-beta2 and those of osteoprotegerin and leptin in native Chinese women.

BACKGROUND: Transforming growth factor-beta 1 (TGF-beta1), TGF-beta2, osteoprotegerin (OPG), and leptin are important cytokines in the regulation of bone remodeling. We investigated the relationship of TGF-beta1 and TGF-beta2 concentrations with those of OPG and leptin in Chinese females. METHODS: The serum concentrations of TGF-beta1, TGF-beta2, OPG, and leptin were measured by ELISA in 459 healthy Chinese females aged 25-80 y. RESULTS: The mean values (+/-SD) of the serum concentrations of TGF-beta1, TGF-beta2, OPG, and leptin in Chinese females were 29.7+/-1.69 microg/l, 13.7+/-3.86 microg/l, 3.81+/-1.96 pmol/l, and 10.5+/-2.01 microg/l, respectively. Further, the serum TGF-beta1 concentrations of postmenopausal women were significantly lower than those of perimenopausal and premenopausal women (24.3+/-1.59 vs 33.4+/-1.69 and 37.6+/-1.64, respectively), while the TGF-beta2 concentrations of postmenopausal women were significantly higher than those of perimenopausal and premenopausal women (14.6+/-3.91 vs 13.5+/-3.93 and 11.7+/-2.68, respectively). The serum TGF-beta1 concentration was found to be significantly negatively correlated with age (r=-0.335, P=0.000) and the TGF-beta2 concentration, to be significantly positively correlated with age (r=0.230, P=0.000). The TGF-beta1 concentration was found to be significantly negatively correlated with both TGF-beta2 (r=-0.261, P=0.000) and OPG (r=-0.313, P=0.000) concentrations; a significantly positive correlation was found between the TGF-beta1 and leptin concentrations (r=0.164, P=0.000) and between TGF-beta2 and OPG concentrations (r=0.432, P=0.000). CONCLUSION: These results provide age-related reference values of TGF-beta1 and TGF-beta2 in Chinese adult women, and reveal the relationships between these cytokines.

[Construction of WISP3 gene's mutants in SEDT-PA and their expression in COS-7 cells].

OBJECTIVE: To construct two types of Wnt-inducible secreted protein 3(WISP3) gene's mutants(1000T/C,840delT) found in spondyloepiphyseal dysplasia tarda with progressive anthopathy (SEDT-PA) patients, and to observe their expression in COS-7 cells. METHODS: Full-length cDNA of wild type WISP3 gene(WT-WISP3) was amplified from human chondrocytes by RT-PCR, and site-directed mutagenesis was used to obtain full-length cDNAs of the mutated WISP3 genes(MUT1000T/C and MUT840delT). The recombined plasmids WT-WISP3/pcDNA3.1(+), MUT1000T/C/pcDNA3.1(+) and MUT840delT/pcDNA3.1(+) were transfected transiently into COS-7 cells by liposome-mediated method, and pcDNA3.1(+) vector was used as a control. The total RNA and protein of the transfected COS-7 cells were extracted after 48 hours of transfection. The expression of WISP3 gene in the transfected COS-7 cells was detected by semi-quantitative RT-PCR and Western blot. RESULTS: By restriction endonuclease analysis and sequencing, the sequence of MUT1000T/C and MUT840delT were consistent with that mutated in SEDT-PA, and the open reading frames matched with the vector sequence. Semi-quantitative RT-PCR and Western blot showed that the recombined plasmids were highly expressed in COS-7 cells. CONCLUSION: WISP3 gene's mutants of SEDT-PA are successfully constructed by genetic recombination, and expressed in COS-7 cells, which lays the foundation for the further study on its molecular functions in SEDT-PA.

Relationship between age-related reference values of serum osteoprotegerin and leptin in native Chinese women and compared with those in women of other races.

BACKGROUND: Osteoprotegerin (OPG) and leptin are important cellular factors in the regulation of bone remodeling. We investigated the serum OPG and leptin in Chinese women. METHODS: The serum OPG and leptin in 690 Chinese women aged 20-81 y were measured by an ELISA. The values of OPG and leptin in women of other races were acquired from previous reports on the same. RESULTS: The geometric mean values (+/- SD) of the serum OPG and leptin in Chinese women were 3.42+/-1.91 pmol/l and 10.5+/-1.99 microg/l, respectively. Further, the serum OPG (4.39+/-1.85 vs 2.74+/-1.81) and leptin (11.4+/-2.21 vs 9.68+/-1.81) in postmenopausal women were significantly higher than in premenopausal women. The serum OPG in middle-aged Chinese women was significantly higher than that in middle-aged Austrian and Icelandic women; however, this is quite contrary to the results obtained in the case of old-aged women. The values of serum leptin in Chinese women were significantly lower than those in white, black, and Mexican American women. CONCLUSIONS: These results provide reliable reference values for OPG and leptin in Chinese adult women. The serum of OPG and leptin differ with ethnicity.

WISP3 suppresses insulin-like growth factor signaling in human chondrocytes.

WISP3 is essential for maintaining cartilage integrity mainly by regulating the expression of collagen II, and mutations of WISP3 linked to spondyloepiphyseal dysplasia tarda with progressive arthropathy (SEDT-PA) can compromise this function and lead to cartilage loss. The aim of this study was to evaluate the effect of WISP3 on insulin-like growth factor (IGF) signaling in human chondrocytes, investigate whether WISP3 up-regulates collagen II through the IGF signaling pathway, and compare IGF signaling between wild-type and mutant WISP3. Experimental results suggest that WISP3 up-regulates collagen II expression and inhibits the activation of IGF-IR, IRS-1, and ERK kinase in human chondrocytes, and mutation of WISP3 augments IGF signaling in human chondrocytes. In addition to the IGF signaling pathway, WISP3 might up-regulate collagen II expression through an IGF-independent signaling cascade.

Cellular and molecular responses in progressive pseudorheumatoid dysplasia articular cartilage associated with compound heterozygous WISP3 gene mutation.

Progressive pseudorheumatoid dysplasia (PPD) is characterized by continuous degeneration and loss of articular cartilage, which has been attributed to mutations in the gene encoding WISP3. We collected a PPD family and analyzed their WISP3 genes mutation. Articular chondrocytes (ACs) were purified from the femurs of a PPD patient after hip replacement surgery. Cell growth, proliferation, and viability were examined. Gene expression profiling and analyses of matrix metalloproteinases (MMP)-1, -3, and -13 proteins were carried out using cDNA differential microarrays, real-time reverse transcriptase-polymerase chain reaction (RT-PCR), immunohistochemistry, and Western blot analysis. We found that two probands carried a deletion (840delT) mutation in maternal allele, which leads to truncated WISP3 protein missing 43 residues in C terminus; and a 1000T>C substitution in paternal allele, which was also passed on to four other members in the PPD kindred. PPD ACs were heterogeneous in size with an enhanced rate of cell proliferation and viability compared with the normal ACs. MMP-1, -3, and -13 mRNA expressions were dereased in PPD ACs. MMP-1, -3, and -13 protein levels, however, were increased in cell lysates from PPD ACs, but markedly decreased in the supernatants from cultured ACs. WISP3 mRNA expression in PPD ACs was also decreased. Our results show, for the first time, a compound heterozygous mutation of WISP3 and a series of cellular and molecular changes disturbing the endochondral ossification in this PPD patient.

[Proliferation, differentiation, and gene expression profile of osteoblast of patient with spondyloepiphyseal dysplasia tarda with progressive arthropathy].

OBJECTIVE: To explore the proliferation, differentiation, and gene expression profile of the osteoblasts (OBs) of patient with spondyloepiphyseal dysplasia tarda with progressive arthropathy (SEDT-PA). METHODS: OBs from the head of femur of a SEDT-PA patient resected during operation were cultured. ELISA was used to examine the bone-specific alkaline phosphatase (BAP), osteocalcin (OC), and osteoprotegrin (OPC) in the lysate of OBs. The proliferation and survival of the OBs were evaluated with MTT method and (3)H-TDR incorporation. Flow cytometry was used to observe the cell cycle. Northern blotting was used to evaluate the mRNA expression of WISP3, a member of the CCN family, mRNA in the OBs. Gene differential expression microarray was used to determine the cDNA expression. Osteoblasts from the head of femur of a patient about the same age with fracture of femur neck was used as control. RESULTS: The cultured OBs from the SEDT-PA patient showed a higher survival capacity (0.86 +/- 0.04 vs 0.71 +/- 0.10) and more (3)H-TDR incorporation (1363 +/- 350 vs 867 +/- 128). The expressions of OC and OPG were down-regulated to the 1/4.3 and 1/4.69 of the control respectively. There was no significant difference in the expression of BAP. WISP3 was very lowly expressed in the OBs of the SEDT-PA patient. In comparison with the normal control, there were up-regulation of 22 genes, including those coding chemotactic factors and inflammatory factors, and down-regulation of 16 genes in the OBs of the SEDT-PA patient with a synthetic effect of more rapid proliferation of OBs and reduction of synthesis of extracellular matrix, resulting in osteopenia. CONCLUSION: Not significantly different between SEDT-PA patient and normal person, the WISP3 expression may not be a direct factor of SEDT-PA.

[Characterization of biologic behaviors and cDNA expression of articular chondrocytes in spondyloepiphyseal dysplasia tarda with progressive arthropathy].

OBJECTIVE: Spondyloepiphyseal dysplasia tarda with progressive arthropathy (SEDT-PA) is an autosomal-recessive hereditary disorder of cartilage homeostasis. The pathogenesis of SEDT-PA is unknown though it has been demonstrated that CCN6 is the SEDT-PA causing gene. The present study characterized the biologic behaviors and cDNA differential expression profile of articular chondrocytes in SEDT-PA. METHODS: The morphologic and functional features of growth, proliferation, differentiation and DNA synthesis of SEDT-PA chondrocytes were determined with cell growth curve, (3)H-TDR incorporation, MTT and flow cytometry. cDNA differential expression profile was carried out with gene microarray containing 8000 genes. Differentially expressed genes were verified by RT-PCR, Western blot and immunohistochemistry. RESULTS: As compared with normal control, the variant chondrocytes were much larger in size with an enhanced ability of proliferation and DNA synthesis and increased ratio of G(2)-M (10.72% vs 0.11%) to S phases (37.0% vs 15.8%). Matrix metalloproteinases (MMPs), which decompose the extra-cellular matrix of the cartilage, accumulated at the endochylema and failed in exocytosis, which lead to the negative feedback of the mRNA transcriptions. The mRNA expression of MMPs was down-regulated. At the same time, the mRNA expression of genes related to cell growth, proliferation and progression of cell cycles were up-regulated, while most of those associated with extracellular matrix, non-collagen proteins and poly-proteoglycans were down-regulated. CONCLUSIONS: The accumulation and failure in exocytosis of the MMPs decompose the extra-cellular matrix of the cartilage. The decreased expression of matrix proteins and polyproteoglycans is involved in the pathogenesis of arthropathy resulted from CCN6 mutation.