New-QiangGuYin-Containing Serum Inhibits Osteoclast-Derived Exosome Secretion and Down-Regulates Notum to Promote Osteoblast Differentiation.

New-QiangGuYin (N-QGY), the addition of sea buckthorn on the basis of QGY formula, is herbal formula widely used clinically in China for the treatment of osteoporosis (OP), but its mechanism warrants further exploration. The mechanisms of QGY and N-QGY in the treatment of OP are probed from the perspective of osteoclast-osteoblast balance. Thirty Sprague-Dawley rats are randomly divided into N-QGY group, QGY group, and Control group. Beyond control rats that orally took normal saline, other rats are orally administered with isometric N-QGY or QGY twice every day for 3 days. The drug-containing serum and control serum are prepared and their effects on osteoclast-derived exosome secretion are determined by bicinchoninic acid assay (BCA), nanoparticle tracking analysis, and Western blot. GW4869 and Interleukin-1ß (IL-1ß) are adopted as the exosome inhibitor and inducer, respectively. Exosome uptake, cell counting kit-8, alkaline phosphatase (ALP) staining, alizarin red staining, enzyme-linked immunosorbent assay, quantitative real-time polymerase chain reaction, and Western blot are performed to examine the effects of altered osteoclast exosome content on osteogenic differentiation of mesenchymal stem cells (MSCs). N-QGY, QGY, and GW4869 inhibit osteoclast-derived exosome secretion and exosome uptake by MSCs, whereas IL-1ß exerted the opposite effects (p < 0.05). Different from IL-1ß, N-QGY, QGY, and GW4869 partially elevated MSC viability, osteocalcin secretion, ALP, RUNX Family Transcription Factor 2 (RUNX2) and Osteopontin (OPN) expressions, and calcium deposition in the osteoclast-MSCs coculture system (p < 0.05). Mechanically, osteoclasts increased Notum protein level but decreased ß-catenin level, which is enhanced by IL-1ß but is reversed by GW4869, QGY, and N-QGY (p < 0.05). And the effect of N-QGY is more conspicuous than that of QGY (P<0.05). N-QGY-containing serum inhibits exosome levels in osteoclasts, thereby enhancing osteogenic differentiation of MSCs via inhibition of Notum protein and promotion of ß-catenin protein.

The prevalence of osteoporotic fractures in the elderly in China: a systematic review and meta-analysis.

BACKGROUND: Prevalence information is the first step in developing preventive procedures or health services. This study was conducted to systematically evaluate the epidemiology of osteoporotic fractures in Chinese elderly aged ≥ 60 years and to provide evidence-based evidence for the prevention and treatment of osteoporotic fractures. METHODS: We identified relevant studies by searching the literature published in PubMed, Web of Science, Cochrane Library, Embase, CNKI, Wanfang Data, and VIP databases from the establishment of the database until August 2022. We used a random-effects model to obtain prevalence estimates and identified sources of heterogeneity and comparisons of prevalence among different groups through subgroup analysis and sensitivity analysis. RESULTS: A total of 29 articles were included in this study, and the prevalence of osteoporosis fractures in elderly Chinese was high (18.9%). The prevalence has increased significantly over the past decade (from 13.2% in 2000-2010 to 22.7% in 2012-2022). The prevalence of osteoporosis is higher in women than in men (18.5% vs 14.3%) and increases with age. The northern region was higher than the southern region (20.3% vs 18.9%), and the spine, hip, and distal forearm were the most common sites of fracture. CONCLUSION: The prevalence of osteoporotic fractures in the Chinese elderly is 18.9%, and timely prevention and treatment are necessary.

[Experimental study on effect of complement C3 on bone formation observed by cell culture in vitro].

OBJECTIVE: To explore effect of lentivirus-mediated complement C3 silencing vector on the osteogenic ability of human B lymphocyte Raji-osteoblast cell line MG63 co-culture system and its mechanism. METHODS: The lentiviral complement C3 silencing vector was constructed and transfected into human B lymphocyte Raji to establish in vitro Raji-osteoblast cell line MG63 co-culture system. The cells were divided into blank control group (without special treatment), complement C3 silencing group (lentiviral complement C3 silencing vector transfection co-culture system) and model group(lentiviral vector transfection co-culture system). The expression of complement C3 in each group was detected by reverse transcription-polymerase chain reaction(RT-PCR) and Western-Blot at 24 h after culture, proliferation of MG63 cells was detected by CCK-8 at 0, 3, 6, 12, 24, 48 and 72 h, apoptosis of MG63 cells in each group was detected by flow cytometry at 24 h after culture, and alkaline phosphatase(AKP) activity of MG63 cells in each group was detected by AKP detection kit, and osteoprotegerin (OPG ) protein expression of MG63 cells in each group was detected by Western-Blot method. RESULTS: RT-PCR results showed that the expression level of C3 in complement C3 silencing group was lower than that in blank control group and model group, Western-Blot results showed that expression of C3 in complement C3 silencing group was lower than that in blank control group and model group, CCK-8 results showed that there was no difference in proliferation ability of MG63 among complement C3 silencing group and blank control group and model group at 3 and 6 h after culture;at 12 h after culture, proliferation ability of MG63 cells with C3 silencing was higher than that of blank control group and model group;at 24, 48 and 72 h after culture, proliferation ability of MG63 cell line with complement C3 silencing group were higher than that of blank control group and model group. Flow cytometry resluts showed that apoptosis of proliferation ability of MG63 cell line with complement C3 silencing group was lower than that of blank control group and model group;AKP detection kit suggested that AKP activity in complement C3 silencing group was higher than that in blank control group and model group, Western-Blot results showed that expression level of OPG protein in complement C3 silencing groupwas higher than that in blank control groupand model group. CONCLUSION: Silencing of complement C3 could enhance bone formation ability of osteoblast MG63, and it takes time to accumulate this ability. Complement C3 may affect osteogenesis by altering OPG / RANKL / RANK axis.