ABSTRACT
BACKGROUND: Bushenhuoxue formula (BSHXF) has shown excellent clinical effects on the treatment of osteoporosis in China. The aim of this study is to determine the anti-osteoporosis effects and precise molecular mechanisms of BSHXF on mouse models. METHODS: Ten-week-old female C57BL/6 J mice were subjected to ovariectomy and provided a daily treatment of BSHXF. At 8 weeks post-surgery, the femurs were harvested for tissue analyses including µCT, histology, qRT-PCR and immunohistochemical (IHC) staining of ß-catenin, ALP and FABP4. To investigate the role of ß-catenin in the anti-osteoporosis effects of BSHXF, relative experiments mentioned above were performed in ß-catenin conditional knockout mice. RESULTS: Ovariectomized (OVX) mice presented severe bone loss and excessive fat accumulation in the chondro-osseous junction underneath the growth plate, with decreased expression of ALP and increased expression of FABP4. BSHXF significantly recovered the OVX-induced abnormal osteogenesis and adipogenesis with the activation of ß-catenin in growth plate chondrocytes. Further, we generated growth plate chondrocyte-specific ß-catenin knockout (ß-cateninGli1ER) mice that exhibited bone loss and fat accumulation in the chondro-osseous junction, similar to the OVX mice. However, BSHXF failed to rescue the osteoporosis-like phenotype in ß-cateninGli1ER mice, indicating the anti-osteoporosis effects of BSHXF act mainly through ß-catenin signaling. No significant restoration of ALP and FABP4 was observed in ß-cateninGli1ER mice after the treatment of BSHXF. CONCLUSIONS: BSHXF attenuates osteoporosis by promoting osteogenic differentiation of growth plate chondrocytes mainly in ß-catenin-dependent manner. BSHXF is considered as a new candidate for the treatment of osteoporosis.
Subject(s)
Chondrocytes/drug effects , Drugs, Chinese Herbal/pharmacology , Osteogenesis/drug effects , Osteoporosis/drug therapy , Adipogenesis/drug effects , Animals , Cell Differentiation/drug effects , Chondrocytes/cytology , Female , Growth Plate/metabolism , Mice , Mice, Inbred C57BL , Mice, Knockout , Osteoporosis/pathology , Ovariectomy , Wnt Signaling Pathway/drug effects , beta Catenin/genetics , beta Catenin/metabolismABSTRACT
A novel approach for highly sensitive and selective genotyping of single-nucleotide polymorphism (SNP) has been developed based on ligation-rolling circle amplification (L-RCA) and stemless molecular beacon. In this approach, two tailored DNA probes were involved. The stemless molecular beacon, formed through the inclusion interactions of γ-cyclodextrin (γ-CD) and bis-pyrene labeled DNA fragment, was served as signal probe. In the absence of mutant target, the two pyrene molecules were bound in the γ-CD cavity to form an excimer and showed a strong fluorescence at 475 nm. It was here named γ-CD-P-MB. The padlock DNA probe was designed as recognition probe. Upon the recognition of a point mutation DNA targets, the padlock probe was ligated to generate a circular template. An RCA amplification was then initiated using the circular template in the presence of Phi29 polymerase and dNTPs. The L-RCA products, containing repetitive sequence units, subsequently hybridized with the γ-CD-P-MB. This made pyrene molecules away from γ-CD cavity and caused a decrease of excimer fluorescence. As a proof-of-concept, SNP typing of ß-thalassemia gene at position -28 was investigated using this approach. The detection limit of mutated target was determined to be 40 fM. In addition, DNA ligase offered high fidelity in distinguishing the mismatched bases at the ligation site, resulting in positive detection of mutant target even when the ratio of the wildtype to the mutant is 999:1. Given these attractive characteristics, the developed approach might provide a great genotyping platform for pathogenic diagnosis and genetic analysis.