Metabolic markers for the early diagnosis of postmenopausal osteoporosis

Gossypol Promotes Wnt/β-Catenin Signaling through WIF1 in Ovariectomy-Induced Osteoporosis

Osteoporosis is one of the most frequent diseases related with age. Previously, we have reported a novel potential drug, gossypol, for the treatment of osteoporosis through its regulation of Wnt/β-catenin signaling. This study aims to identify the detailed mechanism of gossypol in human osteoporosis. Mice injected with gossypol were subjected for RNA-seq analysis and the transcription level of WIF1 was shown to be decreased dramatically in gossypol-treated mice, which was further confirmed by qRT-PCR and western blot analysis. Luciferase reporter assay showed gossypol inhibited the activity of WIF1 and the methylation of WIF1 was significantly upregulated, evidenced by ChIP assay. Cell viability assays demonstrated that gossypol promoted cell proliferation while cotreatment with WIF1 expressing plasmid reversed the effect in a dose- and time-dependent manner. Similarly, cell apoptotic assays and TUNEL assays showed gossypol suppressed cell apoptosis, which was revised by WIF1 overexpression. The mouse model suggested gossypol injection ameliorated osteoporosis, while coinjection of AAV5-WIF1 eliminated the protection effects of gossypol, as evidenced by H&E staining, serum osteocalcin level, serum OPG level, serum RANKL level, bone density, ultimate strength, and postyield displacement. This study is a supplement to the former publication, which reinforced the protection effect of gossypol in human osteoporosis.

Changes of biochemical bone markers during the menopausal transition

We present data on the changes of the bone formation markers osteocalcin (OC), bone-specific alkaline phosphatase (bone ALP) and bone sialoprotein (BSP), as well as the resorption markers pyridinoline (PYD), deoxypyridinoline (DPD), C- and N-terminal telopeptide cross-linked collagen type I (CTX, NTX), and tartrate-resistant acid phosphatase type 5b (TRACP) at five time points during the course of two years in healthy premenopausal, perimenopausal and early postmenopausal women. The prospective study showed that CTX (p<0.001), NTX (p=0.001) and TRACP (p=0.001), as well as bone ALP (p=0.009) and OC (p=0.052), were significantly increased already in the transition period from peri- to postmenopause. The pyridinium crosslinks indicated an increased collagen degradation rate already in the perimenopause (PYD, p=0.017; DPD, p=0.054). Significant inverse correlations with the two years changes of the bone mineral density were found for bone ALP, CTX, OC and DPD in the perimenopausal group. The measurement of a comprehensive panel of biochemical bone markers clearly shows that metabolic changes in bone metabolism appear pronounced in the perimenopause, a period still presenting satisfactory estrogen supply. Thus, the perimenopause is an important phase for a contingent development of osteoporosis.

Bone metabolism during the perimenopausal transition: a prospective study

OBJECTIVE

Changes in biochemical markers of bone formation and resorption were followed over the course of 1 year in premenopausal, perimenopausal and early postmenopausal women.

METHODS

Sixty-four subjects were analyzed, grouped according to their menstrual pattern, menopausal complaints and endocrinological parameters to be premenopausal (n=20), perimenopausal (n=24) or early postmenopausal (n=20). The parameters studied at four visits during the 12-month study period were the urinary pyridinium cross-links pyridinoline (PYD) and deoxypyridinoline (DPD), and N-terminal telopeptide (NTX) as bone resorption markers, as well as osteocalcin (OC) and bone-specific alkaline phosphatase (BAP) in serum, representing bone formation. The longitudinal changes over time as well as intergroup differences were analyzed using generalized estimating equations (GEE) in connection with Wald statistics.

RESULTS

Over the course of 1 year BAP levels decreased in the late premenopausal group (P<0.05). The perimenopausal group exhibited significant changes of PYD, DPD and OC (P<0.01), NTX levels were higher than in premenopause. Postmenopausal subjects had elevated NTX values, while PYD and DPD levels remained close to the perimenopausal range. Only for OC a time effect was seen during postmenopause.

CONCLUSIONS

Changes in bone turnover already begin in late premenopause, when decreased bone formation may precede increased bone resorption. The rise of NTX from late premenopause through early postmenopause indicates diagnostic sensitivity of this parameter to changes in bone metabolism induced by estrogen withdrawal. PYD and DPD do not follow this pattern, but change significantly with time during perimenopause to then remain largely unchanged in early postmenopause.

The association between postmenopausal osteoporosis and kidney-vacuity syndrome in traditional Chinese medicine

The aim of this study was to evaluate the association between postmenopausal osteoporosis and kidney-vacuity syndrome. Eighty-one postmenopausal women were enrolled; their age were between 40 to 65 years old. The mean ages of the non-osteoporosis group and osteoporosis group were 54.0 +/- 4.8 and 58.9 +/- 5.9 years old, respectively. Bone density examination was performed by DEXA technique and the diagnosis of osteoporosis was made by finding 2.5 standard deviations below the bone density of healthy youths. Kidney-vacuity syndrome was deduced according to the diagnostic criteria developed in the National Congress on Chinese Medicine and Sino-Western Combined Geriatric Medicine held in the People's Republic of China in 1986. The results showed that patients with kidney-qi-vacuity and kidney-yin-vacuity were more likely to have osteoporosis than those who were not. No significant difference in the rates of osteoporosis between the kidney-yang-vacuity group and non-kidney-yang-vacuity group was found. The kidney-qi-yin-vacuity group had a higher probability of developing osteoporosis than the kidney-qi-vacuity or kidney-yin-vacuity group. By logistic regression analysis, patients with kidney-qi-vacuity or kidney-yin-vacuity were more likely to develop osteoporosis than those who were not. In conclusion, a marked association between kidney-vacuity syndrome and postmenopausal osteoporosis was observed. Patients with kidney-qi-yin-vacuity syndrome were more likely to get osteoporosis than those with kidney-qi-vacuity syndrome or kidney-yin-vacuity syndrome.

Laboratory assessment of nutritional metabolic bone disease in infants

OBJECTIVES

There are numerous laboratory investigations available for the assessment of an infant with suspected metabolic bone disease (MBD); thus, comprehensive laboratory investigations on every aspect of MBD would impose unnecessary stress to the infant and the costs involved would be prohibitive. An overview of the assessment of an infant with suspected MBD, in particular, nutrition-related bone disease, is presented. Our objectives include an understanding of: 1. the importance of appropriate information from history and physical examination to guide the laboratory investigations; 2. relevance and limitations of specific laboratory investigations: a. radiologic studies include diagnostic radiographs and quantitative bone mass determination by dual energy x-ray absorptiometry, b. biochemical measurements to determine mineral homeostasis and bone turnover, c. vitamin (vitamin D metabolites) and hormonal (parathyroid hormone and calcitonin) measurements; with respect to diagnosis and monitoring of the natural progress or response to therapy.

CONCLUSION

Relevant information from clinical history and physical examination, and an understanding of the role and limitations of various laboratory investigations, would allow the optimal utilization of laboratory tests in the assessment of an infant with MBD.