[Effect of the Wnt/LRP5/β-catenin signaling pathway on the pathogenesis of postmenopausal osteoporosis].

OBJECTIVE

To investigate the role of the Wnt/LRP5/β-catenin signaling pathway in the pathogenesis of postmenopausal osteoporosis.

METHODS

Fifty female Wistar rats aged 6-month-old, were randomly divided into control group (NS, n = 24) and ovariectomized group (NOVX, n = 26), NOVX underwent bilateral ovariectomy. At 0, 4 and 8 weeks, all of rats were measured blood estrogen (E(2)) and bone mineral density (BMD), 4 and 8 weeks, low density lipoprotein receptor-related protein 5 (LRP5), β-catenin and Runx2 mRNA in bone were measured respectively by reverse transcription (RT)-PCR.

RESULTS

In 4 and 8 weeks, compared with NS which had (117 ± 29) and (114 ± 15) pmol/L in E(2) level, (0.098 ± 0.016) and (0.095 ± 0.028) g/cm(2) in BMD, NOVX had significantly decreased to (92 ± 15) and (95 ± 22) pmol/L in E(2) level (P < 0.05), (0.076 ± 0.016) and (0.052 ± 0.013) g/cm(2) in BMD values (P < 0.01). And bone tissue LRP5, β-catenin and Runx2 mRNA expression was 1.02 ± 0.06, 1.04 ± 0.05, 1.07 ± 0.21 in NS, NOVX was significantly reduced to 0.97 ± 0.04, 0.58 ± 0.05, 0.86 ± 0.03 (P < 0.05).

CONCLUSION

Wnt/LRP5/β-catenin signaling pathway may be important in the pathogenesis of postmenopausal osteoporosis.