Background The pathogenic mechanisms of postmenopausal osteoporosis (PMOP) development are complex and are related to multiple cellular signalling transduction pathways. The aim of this study was to compare the effects of electroacupuncture (EA) at GV4/GV6 versus BL20/BL23 on the bones in ovariectomised (OVX) rats to explore the pathways that mediate the effects of EA on bone.
Methods Forty female Sprague-Dawley rats were allocated to one of four groups (n=10 rats each) that received sham surgery (Sham group), OVX surgery only (OVX group), OVX surgery plus EA at GV4/GV6 (GV group) and OVX surgery plus EA at BL20/BL23 (BL group). Bone turnover markers osteocalcin (OC) and tartrate-resistant acid phosphatase 5b (TRACP 5b) were measured in serum, and bone mineral density (BMD) of the lumbar vertebrae and histomorphology of the femur were evaluated. Moreover, the expression of osteoprotegerin (OPG) and receptor activator of nuclear factor-κB ligand (RANKL) was detected by ELISA. The expression of lipoprotein receptor-related protein (LRP) 5, β-catenin, runt-related transcription factor (Runx) 2 involving Wnt/β-catenin signalling and p38, c-Jun N-terminal kinase (JNK) and extracellular regulated protein kinases 1/2 involving mitogen-activated protein kinase signalling were determined by Western blotting.
Results The two EA-treated groups demonstrated increased levels of OC and the BMD of lumbar vertebrae, decreased levels of TRACP 5b and improved bone microstructure in the femur, compared with the untreated OVX group (P<0.05). Histomorphology analysis showed that EA treatment significantly increased the values of the trabeculae (µm), trabecular area (%) and trabecular bone number (per mm) and reduced trabecular separation (mm), compared with the OVX group. In addition, the ratio of OPG to RANKL and LRP5, β-catenin and Runx2 expression were significantly upregulated, while the expression of phosphorylated (p)-p38 and p-JNK were downregulated in EA-treated groups compared with the OVX group.
Conclusion EA attenuates PMOP and it appears that the mechanism involves the regulation of multiple targets and pathways.
- complementary medicine
- bone diseases
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Contributors XZ participated in study design and manuscript editing, and in all experiment procedures. YN mainly developed the postmenopausal osteoporosis model and performed the Western blot analysis. CS performed the ELISAs. GW performed the lumbar vertebra bone mineral density analysis. QC analysed the femoral histomorphology. SH performed the Western blot analysis. YL conceived the study and design, analysed the data and prepared the manuscript. All authors read, discussed and approved the final version of the manuscript accepted for publication.
Funding The study was supported by grants from the National Natural Science Foundation of China (no. 81574003 and 81674054) and Science and Technology Project in Fujian Province Department of Education (no. JK2015021).
Competing interests None declared.
Ethics approval The principles of laboratory animal care were in compliance with the Animal Protection Law of the People’s Republic of China (2001). This study was approved by the ethics committee at Fujian University of Traditional Chinese Medicine and follows international guidelines for the care and use of animals consistent with the National Institutes of Health ’Guide for the Care and Use of Laboratory Animals' (no. 20140120).
Provenance and peer review Not commissioned; externally peer reviewed.
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