Lin Huang

Aims: Osteoporosis primarily results from age-related declines in bone marrow mesenchymal stem cell (BMSC) differentiation into osteoblasts; however, the regulatory mechanisms remain unclear. Methods: Integrated analysis of Gene Expression Omnibus (GEO) and RNA sequencing (RNA-seq) data identified a key osteogenic regulator. Western blot, reverse transcription quantitative polymerase chain reaction (RT-qPCR), RNA-seq, immunohistochemistry (IHC), alkaline phosphatase (ALP), and alizarin red S (ARS) staining were employed to elucidate the functional and mechanistic aspects of modulating osteogenic differentiation. A C57 mouse tibial drill-hole model was used to evaluate therapeutic potential. Results: RNA-seq identified baculoviral inhibitor of apoptosis (IAP) repeat-containing protein 3 (BIRC3) as a potential regulator of BMSC osteogenesis, showing significant upregulation during BMSC osteogenic differentiation and upon monocyte stimulation. BIRC3 positively correlated with ALP and ARS staining intensity and significantly enhanced the expression of (runt-related transcription factor 2) RUNX2 and ALP proteins. RNA-seq, RT-qPCR, and western blot data indicated that BIRC3 positively regulates the expression of nerve growth factor receptor (NGFR). NGFR also promoted the osteogenic differentiation of BMSCs. Further experiments demonstrated that BIRC3 regulates BMSC osteogenesis through NGFR. Through XAV939 treatment, we demonstrated that both BIRC3 and NGFR promoted BMSC osteogenesis by enhancing β-catenin expression and nuclear translocation, thereby defining the functional role of the BIRC3/NGFR/β-catenin axis in BMSCs. In C57 mouse tibial bone defect models, BIRC3 overexpression group exhibited significantly enhanced callus formation and ossification compared to the control group. Conclusion: BIRC3 regulates BMSC osteogenic differentiation via NGFR/β-catenin signalling in vitro and promotes bone healing in vivo, suggesting therapeutic potential for osteoporosis and bone defects. Cite this article: Bone Joint Res 2026;15(10):1248–1262.

To evaluate whether preoperative oral antithrombotic therapy increases the perioperative bleeding tendency in patients undergoing spinal fusion with low-molecular-weight heparin (LMWH) bridging, and to compare their bleeding risk with that of a general surgical cohort. Patients undergoing spinal fusion (2019-2024) at two centers were categorized into three groups: (1) Oral Antithrombotics group (history of preoperative antithrombotic use with LMWH bridging), (2) No Oral Antithrombotics group (no preoperative antithrombotic history, receiving perioperative LMWH prophylaxis), and (3) Blank group (a 1:1 matched cohort without preoperative antithrombotic history or perioperative LMWH prophylaxis). The Oral Antithrombotics group exhibited significantly higher intraoperative blood loss, increased transfusion rates, and longer hospital stays compared to the Blank group (p < 0.05). In the lumbar surgery subgroup, the Oral Antithrombotics group showed higher intraoperative and overt blood loss compared to the No Oral Antithrombotics group (p < 0.05), whereas no such differences were observed in cervical surgery. While preoperative oral antithrombotic therapy with LMWH bridging does not raise the risk of severe bleeding events after spinal fusion, it correlates with an enhanced perioperative bleeding tendency, especially in lumbar fusion procedures.

The damage of ferroptosis is related to the pathogenesis of intervertebral disc degeneration (IDD). N6-methyladenosine (m6A) modification accounts for more than 80% of RNA modifications in eukaryotic cells. However, the key role of m6A related ferroptosis-related genes (FRGs) in IDD remain explorable. Firstly, batch correction between datasets was performed. Weighted gene co-expression network analysis (WGCNA) was then conducted to acquire the most relevant module genes. Differentially expressed genes (DEGs) between the IDD and Normal Group were obtained by differential analysis subsequently. Next, according to the Pearson correlation and the intersection of m6A and FRGs related genes, m6A-FRGs related genes were selected. Additionally, we intersected module genes, DEGs and m6A-FRGs related genes to obtain DEGs of m6A-FRGs related module genes (m6A-FRGs-DEGs). Least absolute shrinkage and selection operator (LASSO) was applied to get HUBgenes. After, we conducted gene set enrichment analysis (GSEA) to gain function items and related pathways of HUBgenes. Single sample gene set enrichment analysis (ssGSEA) and wilcox.test were proceeded to analyse differences in relative abundance of immune cells between the IDD and Normal Groups, and a nomogram was constructed based on significantly different HUBgenes. The Comparative Toxicogenomics Database (CTDbase) was then applied to predict potential drugs or molecular compounds that could modulate HUBgenes. Last but not least, we performed the quantitative real-time fluorescence PCR (qRT-PCR) to verify HUBgenes. 181 m6A-FRGs-DEGs were acquired by the intersection of key module genes (from MEtan, MEsalmon, MEbrown and MEgreen), 362 DEGs and 15,678 m6A-FRGs related genes. Subsequent analysis showed that HUBgenes (ZNF595, PLXDC1, FNBP1L, KLRB1, NRCAM, PPCDC, C9orf139, SIGLEC17P, RRAS2 and DPRXP4) significantly participated in positive regulation of cytokine production, mitochondrial inner membrane and organellar ribosome. Besides, the relative abundance of neutrophils was found significantly different between IDD and normal groups. A nomogram was constructed based on ZNF595 and RRAS2, and there were 11 drugs targeted on ZNF595, while 118 drugs predicted based on RRAS2 such as Tetrachlorodibenzodioxin, Bisphenol A and Benzo(a)pyrene. Lastly, ZNF595 and RRAS2 were both obviously up-regulated in IDD according to the qRT-PCR. Our research suggested 10 HUBgenes were significantly associated with IDD, providing more evidence about the vital role of HUBgenes in IDD.

Bone is a dynamic tissue that undergoes microdamage and requires remodeling to replace old bone matrix. This process demands a tight coupling between bone resorption and bone formation. Aberrant internal environment can decouple these processes, reducing bone mass and compromising mechanical properties. High mobility group box-1 (HMGB1) is a multifunctional protein binding to advanced glycosylation end product-specific receptor (RAGE) and toll-like receptors (TLRs), regulating DNA repair, cytokine production, inflammation, cell proliferation, programmed cell death (PCD). Extracellular HMGB1 serves not only as a damage-associated molecular pattern (DAMP) that promotes cytokine storms and inflammatory cascade responses but also modulates osteogenesis, osteoclastogenesis and angiogenesis. Under physiological or acute trauma conditions, HMGB1 recruits osteoblasts, osteoclasts, and various immune cells to coordinate inflammation and immune responses, clearing pathogens and promoting bone repair. However, chronic HMGB1 overrelease strengthens osteoclastogenesis and bone resorption, leading to uncoupled bone remodeling and homeostatic imbalance. Thus, HMGB1 plays indispensable roles in bone metabolism and immune regulation. Current research on its involvement in bone remodeling remains incomplete and lacks systematic elucidation. This review aims to bridge this critical knowledge gap and provide a comprehensive reference for future investigations.

The decreased osteogenesis of bone marrow mesenchymal stem cells (BMSCs) is an important factor causing bone loss. Nevertheless, its deep molecular mechanism has still not been fully clarified. To elucidate the regulatory mechanisms underlying BMSC osteogenesis, we conducted a bioinformatics screen using public datasets from the Gene Expression Omnibus (GEO) database to identify genes displaying significant expression dynamics during the osteogenic differentiation of BMSCs. We observed a significant upregulation of FK506 Binding Protein 5 (FKBP5) expression during the osteogenic differentiation of BMSCs. Besides, knockdown and overexpression of FKBP5 could reduce and increase osteogenic markers and Alizarin Red S (ARS) staining, respectively. Enrichment analysis of RNA sequencing (RNA-seq) demonstrated that downregulation of FKBP5 activated IFNα/β signaling pathway. FKBP5 overexpression relieved the inhibitory effect of IFNβ on osteogenesis. In addition, one of the upregulated interferon-stimulated genes (ISG), interferon-induced protein with tetratricopeptide repeats 2 (IFIT2), negatively regulated osteogenesis of BMSCs. IFIT2 knockdown rescued negative effect on osteogenesis caused by downregulation of FKBP5. Hydroxyapatite scaffold implanted in nude mice and drilled tibiae model in C57BL/6 mice confirmed positive role of FKBP5 in osteogenesis in vivo. Therefore, we determined the beneficial effect of FKBP5 on osteogenesis of BMSCs and validated the critical role of FKBP5/IFIT2 axis in this process. These findings might contribute to comprehension and treatment of bone diseases, like osteoporosis and bone fracture. Graphical abstract

Mesenchymal stem cells (MSCs), known for their ability to differentiate into osteoblasts, play a pivotal role in bone metabolism. In our previous investigations, we identified a novel long non-coding RNA (lncRNA) named MCP1 Regulatory Factor (MRF), which exhibits significant involvement in immune regulation of BMSCs. Moreover, we observed noticeable expression changes of MRF during the osteogenic differentiation of BMSCs. However, the exact role and underlying mechanism of MRF in the osteogenic differentiation of BMSCs remain elusive. QRT-PCR analysis was employed to assess the expression levels of MRF. RNA interference and overexpression plasmids were utilized to modulate MRF expression, allowing for the observation of changes in the osteogenic differentiation capacity of BMSCs. Downstream pathways involved in the MRF-mediated regulation of BMSCs' osteogenic differentiation were predicted using transcriptome sequencing. The functionality of MRF in vivo was validated through a mouse tibial drilling defect model. In patients with osteoporosis, there is a notable increase in the expression of MRF within BMSCs. During the osteogenic differentiation of BMSCs, the MRF expression progressively decreases. The knockdown of MRF significantly enhances the osteogenic differentiation of BMSCs, promoting an increased expression of bone-related proteins such as RUNX2, ALP, and COL1A1. Transcriptome sequencing and western blot indicated that cAMP/PKA/CREB signaling pathway was significantly activated after lncRNA-MRF knockdown. Moreover, in the mouse tibial drilling defect model, MRF knockdown significantly promotes ossification in vivo. MRF modulates the cAMP/PKA/CREB signaling pathway via the follicle stimulating hormone receptor (FSHR), thereby influencing the ossification differentiation of BMSCs. Our research suggests that MRF may serve as a potential target for bone-related disorders.

Background: Intervertebral disc degeneration (IDD) is an increasingly important cause of low back pain (LBP) that results in substantial health and economic burdens. Inflammatory pathway activation and the production of reactive oxygen species (ROS) play vital roles in the progression of IDD. Several studies have suggested that phillyrin has a protective role and inhibits inflammation and the production of ROS. However, the role of phillyrin in IDD has not been confirmed. Purpose: The purpose of this study was to investigate the role of phillyrin in IDD and its mechanisms. Study design: To establish IDD models in vivo, ex-vivo, and in vitro to verify the function of phillyrin in IDD. Method: The effects of phillyrin on extracellular matrix (ECM) degeneration, inflammation, and oxidation in nucleus pulposus (NP) cells were assessed using immunoblotting and immunofluorescence analysis. Additionally, the impact of phillyrin administration on acupuncture-mediated intervertebral disc degeneration (IDD) in rats was evaluated using various techniques such as MRI, HE staining, S-O staining, and immunohistochemistry (IHC). Result: Pretreatment with phillyrin significantly inhibited the IL-1β-mediated reduction in the degeneration of ECM and apoptosis by alleviating activation of the NF-κB inflammatory pathway and the generation of ROS. In addition, in vivo and ex-vivo experiments verified the protective effect of phillyrin against IDD. Conclusion: Phillyrin can attenuate the progression of IDD by reducing ROS production and activating inflammatory pathways.