Dencichine prevents ovariectomy-induced bone loss and inhibits osteoclastogenesis by inhibiting RANKL-associated NF-κB and MAPK signaling pathways

Identification of a potential signature to predict the risk of postmenopausal osteoporosis

BACKGROUND

Postmenopausal osteoporosis (PMOP) is related to the elevated risk of fracture in postmenopausal women. Thus, to effectively predict the occurrence of PMOP, we explored a novel gene signature for the prediction of PMOP risk.

METHODS

The WGCNA analysis was conducted to identify the PMOP-related gene modules based on the data from GEO database (GSE56116 and GSE100609). The "limma" R package was applied for screening differentially expressed genes (DEGs) based on the data from GSE100609 dataset. Next, LASSO Cox algorithm were applied to identify valuable PMOP-related risk genes and construct a risk score model. GSEA was then conducted to analyze potential signaling pathways between high-risk (HR) score and low-risk (LR) score groups.

RESULTS

A novel risk model with five PMOP-related risk genes (SCUBE3, TNNC1, SPON1, SEPT12 and ULBP1) was developed for predicting PMOP risk status. RT-qPCR and western blot assays validated that compared to postmenopausal non-osteoporosis (non-PMOP) patients, SCUBE3, ULBP1, SEPT12 levels were obviously elevated, and TNNC1 and SPON1 levels were reduced in blood samples from PMOP patients. Additionally, PMOP-related pathways such as MAPK signaling pathway, PI3K-Akt signaling pathway and HIF-1 signaling pathway were significantly activated in the HR-score group compared to the LR-score group. The circRNA-gene-miRNA and gene-transcription factor networks showed that 533 miRNAs, 13 circRNAs and 40 TFs might be involved in regulating the expression level of these five PMOP-related genes.

CONCLUSION

Collectively, we developed a PMOP-related gene signature based on SCUBE3, TNNC1, SPON1, SEPT12 and ULBP1 genes, and higher risk score indicated higher risk suffering from PMOP.

Determination of Dencichine in Panax notoginseng in the Forest and Field Using High Performance Liquid Chromatography

Dencichine is a nonprotein amino acid, an effective ingredient in Panax notoginseng with hemostatic and anti-inflammatory effects. There are few studies on the effects of regions and cultivation models on the accumulation of dencichine. In the current study, the content of dencichine in P. notoginseng collected from its global cultivation and trading center Yunnan, China, (>640 samples) was determined using an optimized high-performance liquid chromatography method coupled with a diode array detector but without derivatization. The recovery rate of this method was 80-110%, the relative standard deviation was <10%, and the limits of detection and quantification were 0.003% (w/w) and 0.01% (w/w), respectively. The content of dencichine in each part of P. notoginseng was as follows: rootlets (39.59%) > main roots (29.91%) > leaves (16.21%) > stems (14.29%). For leaves, P. notoginseng in the forest (5.52 ± 2.26 mg/g) was significantly higher than that in the field (3.93 ± 1.72 mg/g) but opposite for main roots. The origins and altitudes made different contributions to the accumulation of dencichine in P. notoginseng. This study provides an effective analytical method to determine dencichines in various parts of P. notoginseng from different origins and altitudes and supports quality control and product development of P. notoginseng.

Preparation of Rosin-Based Composite Membranes and Study of Their Dencichine Adsorption Properties

In this work, rosin-based composite membranes (RCMs) were developed as selective sorbents for the preparation of dencichine for the first time. The rosin-based polymer microspheres (RPMs) were synthesized using 4-ethylpyridine as a functional monomer and ethylene glycol maleic rosinate acrylate as a crosslinking. RCMs were prepared by spinning the RPMs onto the membranes by electrostatic spinning technology. The optimization of various parameters that affect RCMs was carried out, such as the ratio concentration and voltage intensity of electrospinning membrane. The RCMs were characterized by SEM, TGA and FT-IR. The performances of RCMs were assessed, which included adsorption isotherms, selective recognition and adsorption kinetics. The adsorption of dencichine on RCMs followed pseudo-second-order and adapted Langmuir–Freundlich isotherm model. As for the RCMs, the fast adsorption stage appeared within the first 45 min, and the experimental maximum adsorption capacity was 1.056 mg/g, which is much higher than the previous dencichine adsorbents reported in the literature. The initial decomposition temperature of RCMs is 297 °C, the tensile strength is 2.15 MPa and the elongation at break is 215.1%. The RCMs have good thermal stability and mechanical properties. These results indicated that RCMs are a tremendously promising adsorbent for enriching and purifying dencichine from the notoginseng extracts.

Incorporation of Bone Morphogenetic Protein-2 and Osteoprotegerin in 3D-Printed Ti6Al4V Scaffolds Enhances Osseointegration Under Osteoporotic Conditions

Osteoporosis is an age-related metabolic disease that results in limited bone regeneration capacity and excessive osteoclast activity. After arthroplasty in patients with osteoporosis, poor interface osseointegration resulting from insufficient bone regeneration ability often leads to catastrophic complications such as prosthesis displacement and loosening and periprosthetic fractures. In this study, we prepared a thermosensitive hydrogel loaded with bone morphogenetic protein-2 (BMP-2) to promote osteogenesis and osteoprotegerin (OPG) to inhibit excessive osteoclast activity. To construct three-dimensional (3D)-printed composite scaffolds for implantation, a hydrogel loaded with drugs was injected into porous Ti6Al4V scaffolds. The 3D-printed composite scaffolds showed good biocompatibility and sustained release of BMP-2 and OPG for more than 20 days. In vitro experiments indicated that composite scaffolds promoted osteogenic differentiation and reduced the osteoclastic activation simultaneously. Remarkably, immunofluorescence staining, micro-CT, histological, and biomechanical tests demonstrated that the sustained release of both BMP-2 and OPG from composite scaffolds significantly improved bone ingrowth and osseointegration in osteoporotic defects. In conclusion, this study demonstrated that the BMP-2- and OPG-loaded 3D-printed composite scaffolds can potentially promote osseointegration for osteoporotic patients after joint replacement.