Identification and immunological role of cuproptosis in osteoporosis.

Background: osteoporosis is a skeletal disorder disease features low bone mass and poor bone architecture, which predisposes to increased risk of fracture. Copper death is a newly recognized form of cell death caused by excess copper ions, which presumably involve in various disease. Accordingly, we intended to investigate the molecular clusters related to the cuproptosis in osteoporosis and to construct a predictive model. Methods: we investigated the expression patterns of cuproptosis regulators and immune signatures in osteoporosis based on the GSE56815 dataset. Through analysis of 40 osteoporosis samples, we investigated molecular clustering on the basis of cuproptosis--related genes, together with the associated immune cell infiltration. The WGCNA algorithm was applied to detect cluster-specific differentially expressed genes. Afterwards, the optimum machine model was selected by calculating the performance of the support vector machine model, random forest model, eXtreme Gradient Boosting and generalized linear model. Nomogram, decision curve analysis, calibration curves, and the GSE7158 dataset was utilizing to confirm the prediction efficiency. Results: Differences between osteoporotic and non-osteoporotic controls confirm poorly adjusted copper death-related genes and triggered immune responses. In osteoporosis, two clusters of molecules in connection with copper death proliferation were outlined. The assessed levels of immune infiltration showed prominent heterogeneity between the different clusters. Cluster 2 was characterized by a raised immune score accompanied with relatively high levels of immune infiltration. The functional analysis we performed showed a close relationship between the different immune responses and specific differentially expressed genes in cluster 2. The random forest machine model showed the optimum discriminatory performance due to relatively low residuals and root mean square errors. Finally, a random forest model based on 5 genes was built, showing acceptable performance in an external validation dataset (AUC = 0.750). Calibration curve, Nomogram, and decision curve analyses also evinced fidelity in predicting subtypes of osteoporosis. Conclusion: Our study identifies the role of cuproptosis in OP and essentially illustrates the underlying molecular mechanisms that lead to OP heterogeneity.

Exploring the effect of the "quaternary regulation" theory of "peripheral nerve-angiogenesis-osteoclast-osteogenesis" on osteoporosis based on neuropeptides.

Osteoporosis is a common bone metabolic disease among the middle-aged and elderly, with its high incidence rate and a major cause of disability and mortality. Early studies found that bone metabolic homeostasis is achieved through osteogenesis-osteoclast coupling. Although current anti-osteoporosis drugs can attenuate bone loss caused by aging, they present specific side effects. With the discovery of CD31hi Emcnhi blood vessels in 2014, the effect of H-type blood vessels on bone metabolism has been valued by researchers, and the ternary regulation theory of bone metabolism of "Angiogenesis-Osteoclast-Osteogenesis" has also been recognized. Nowadays, more studies have confirmed that peripheral nerves substantially impact bone metabolism. However, due to the complex function of peripheral nerves, the crosstalk mechanism of "Peripheral nerve-Angiogenesis-Osteoclast-Osteogenesis" has not yet been fully revealed. Neuropeptide serves as signaling molecules secreted by peripheral nerves that regulate blood vessels, osteoblasts, and osteoclasts' functions. It is likely to be the breakthrough point of the quaternary regulation theory of "Peripheral nerve-Angiogenesis-Osteoclast-Osteogenesis". Here, we discuss the effect of peripheral nerves on osteoporosis based on neuropeptides.

Cistanoside A promotes osteogenesis of primary osteoblasts by alleviating apoptosis and activating autophagy through involvement of the Wnt/ß-catenin signal pathway.

Background: As a phenylethanoid glycoside extracted from Cistanche deserticola, cistanoside A has been shown to have antioxidative effects. In recent years, it has been found to play an important role in osteoporosis. Methods: Primary osteoblasts were randomly divided into a cistanoside A (Cis A)-1 group (5 µM), a Cis A-2 group (10 µM), and a Cis A-3 group (20 µM) to screen the optimal dose. Then, cells were treated with Rapamycin (Rapa), 3-MA, Dickkopf-1 (DKK-1), 3MA + Cis A (10 µM), and DKK-1 + Cis A (10 µM). After a certain period of routine culture, Alkaline Phosphatase (ALP) and Alizarin Red S Staining were performed again and the cells were collected for subsequent experiments including immunofluorescence staining, western blotting, transmission electron microscopy, mitochondrial membrane measurement, and Annexin-V-Fluorescein isothiocyanate (Annexin-V-FITC). Results: The optimal Cis A dose that preserved osteoblast viability and activated osteogenesis was 10 µM. It appeared that Cis A (10 µM) decreased apoptosis and augmented autophagy via increasing microtubule-associated protein light chain 3 (LC3)-I/II expressions as well as raising Wnt/ß-catenin signal pathway activity. The addition of 3-MA further inhibited osteogenic differentiation and suppressed Wnt/ß-catenin signal pathway activity to increase apoptosis while reducing autophagy levels. A combination of Cis A and DKK-1 resulted in higher levels of apoptosis but lower levels of autophagy. Conclusions: Cis A appears to be a potent inducer of autophagy and inhibitor of apoptosis in primary osteoblasts by working through the Wnt/ß-catenin signal pathway, thereby resulting in enhanced osteogenic differentiation.

The efficacy and safety of traditional Chinese medicine's tonifying-kidney, strengthening-spleen, and invigorating-blood circulation (Bushen-Jianpi-Huoxue) principle for type 2 diabetes mellitus with osteoporosis: A protocol for systematic review and meta-analysis.

BACKGROUND: Type 2 diabetes mellitus (T2D) and osteoporosis (OP) often coexist, and both are systemic metabolic diseases and seriously increase the risk of fragility fracture. However, there is no specific Western medicine for the treatment of T2D with OP (T2DOP). As reported in clinical and experimental studies, traditional Chinese medicine (TCM) based on principle of tonifying-kidney, strengthening-spleen, and invigorating blood circulation (Bushen-Jianpi-Huoxue) (BSJPHX) has significant efficacy against T2DOP. This protocol will be designed for a systematic review and meta-analysis to assess the efficacy and safety of TCM BSJPHX principle in the treatment of T2DOP. METHODS: All relevant randomized controlled trials (RCTs) related to TCM therapies conducted in BSJPHX principle for T2DOP will be searched in the 8 electronic databases: PubMed, Cochrane Library, Wed of Science, EMBASE, Chinese National Knowledge Infrastructure Database (CNKI), Chinese Biomedical Literatures Database (CBM), Chinese Scientific Journal Database (VIP), Wanfang Database, from inception to October 2020. The main outcomes will contain: fasting blood glucose (FPG), 2 hours postprandial blood glucose (2hPG), glycosylated hemoglobin (HbA1c), serum calcium, bone mineral density (BMD), TCM syndrome integral, and the additional outcomes will consist of visual analog scale (VAS), and adverse events. Two reviewers will independently carry out literature search, data selection and synthesis, and literature quality assessment. In case of any dispute, it will be settled by group discussion. Assessment of risk of bias, reporting bias, and data synthesis would be performed with Review Manager software (Rev-Man 5.3). RESULT: This study will collate and summarize the various current evidences of TCM BSJPHX principle for T2DOP. CONCLUSION: This study will offer convincing evidence for judging the efficacy and safety of TCM BSJPHX principle for T2DOP. PROSPERO REGISTRATION NUMBER: CRD42020218877.