Osteoblast-derived exosomes promote osteogenic differentiation of osteosarcoma cells via URG4/Wnt signaling pathway

Substrate stiffness modulates osteogenic and adipogenic differentiation of osteosarcoma through PIEZO1 mediated signaling pathway

Most osteosarcoma (OS) cases exhibit poor differentiation at the histopathological level. Disruption of the normal osteogenic differentiation process results in the unregulated proliferation of precursor cells, which is a critical factor in the development of OS. Differentiation therapy aims to slow disease progression by restoring the osteogenic differentiation process of OS cells and is considered a new approach to treating OS. However, there are currently few studies on the mechanism of differentiation of OS, which puts the development of differentiation therapeutic drugs into a bottleneck. Substrate stiffness can regulate differentiation in mesenchymal stem cells. Evidence supports that mesenchymal stem cells and osteoblast precursors are the origin of OS. In this study, we simulated different stiffnesses in vitro to investigate the mechanism of substrate stiffness affecting differentiation of OS. We demonstrate that Piezo type mechanosensitive ion channel component 1 (PIEZO1) plays a critical regulatory role in sensing substrate stiffness in osteogenic and adipogenic differentiation of OS. When OS cells are cultured on the stiff substrate, integrin subunit beta 1 (ITGB1) increases and cooperates with PIEZO1 to promote Yes-Associated Protein (YAP) entering the nucleus, and may inhibit EZH2, thereby inhibiting H3K27me3 and increasing RUNX2 expression, and cells differentiate toward osteogenesis. Our results provide new insights for research on differentiation treatment of OS and are expected to help identify new targets for future drug design.

Improving Patients' Quality of Life After Surgical Treatment of Primary Malignant Bone Tumors Using a Training 3D Model

BACKGROUND

Bone neoplasms significantly reduce the patient's quality of life (QoL) not only during the manifestation of the primary disease but also at various treatment stages.

AIM

To study the QoL indicators in patients with primary malignant bone tumors before and after surgical treatment using a training 3D model.

MATERIALS AND METHODS

44 patients with primary malignant tumors of the lower extremities (osteosarcoma and chondrosarcoma) were treated by surgery. 3D modeling was used to plan the surgical intervention. 3D printing of the models of the pathological foci was performed by the method of layer-by-layer deposition (Fused Deposition Modeling, FDM) using a Creatbot D600 3D printer. The QoL index of patients before and 3 weeks after surgical treatment was measured by the arithmetic sum of the scores of the QLQ-C30 simplified version questionnaire.

RESULTS

The surgical removal of a tumor using a training 3D model had a positive effect on the QoL of patients. Before treatment, the QoL index was on average 7.4 ± 1.2 points, and after treatment 9.4 ± 1.3 points, that is, by 27% higher.

CONCLUSIONS

The use of training 3D models not only implements a strategy of personalized treatment and improves the QoL of patients but also contributes to optimization of the postoperative rehabilitation.

The relationship between URG4 and clinicopathologic parameters and its effect on two-year survival in gastric carcinoma

AIM

Gastric cancer (GC) is the third leading cause of cancer-related deaths worldwide. The present study examined the relationship between Upregulated gene 4 (URG4) expression, an oncogene involved in the development of gastric carcinoma, and clinicopathologic parameters including Human epidermal growth factor receptor 2 (HER2) status. The study aimed to investigate the importance of URG4 as a prognostic factor for 2-year survival in GCs, which are usually in the advanced stage at the time of diagnosis and have a rapid course.

METHODS

In 61 patients with GC, URG4 expression results in paraffin blocks were compared with the patients' clinicopathologic, 2-year survival, and HER2 results.

RESULTS

Among the patients, 24 (39 %) had low URG4 scores (scores 0-4) and 37 (61 %) had high URG4 scores (scores 6-9). While the HER2 score was negative in 52 (85 %)patients, it was positive in 9 (15 %). URG4 expression values were significantly correlated with tumor (T) stage and lymphovascular invasion (LVI) (p < 0.005), whereas no significant correlation was determined between other pathological prognostic factors and HER2 status (p > 0.005). During the two-year period, 32 (52 %) patients survived and 29 (48 %) died. The mean duration of survival was 75.20 ± 35.22 weeks. A significant correlation was determined between URG4 values and survival and mortality results (p < 0.05).

CONCLUSION

We revealed a correlation (p < 0.005) between increased URG4 scores with increased T stage and LVI. We demonstrated an association between increased URG4 expression and survival time and mortality in patients with GC during the first two years of survival (p < 0.005) and URG4 and HER2 yielded similar results as prognostic factors in the survival of the patients URG4 is an essential oncogene in malignancies, especially in gastric GC, requiring further research and development in prognostic and therapeutic areas.

Exosomes from Human Periodontal Ligament Stem Cells Promote Differentiation of Osteoblast-like Cells and Bone Healing in Rat Calvarial Bone

Deep caries and severe periodontitis cause bone resorption in periodontal tissue, and severe bone resorption leads to tooth loss. Periodontal ligament stem cells (PDLSCs) are important for the healing of defective periodontal tissue. It is increasingly understood that healing of periodontal tissue is mediated through the secretion of trophic factors, particularly exosomes. This study investigated the effects of exosomes from human PDLSCs (HPDLSCs-Exo) on human osteoblast-like cells in vitro and on the healing of rat calvarial bone defects in vivo. HPDLSCs-Exo were isolated and characterized by their particle shape, size (133 ± 6.4 nm), and expression of surface markers (CD9, CD63, and CD81). In vitro results showed that HPDLSCs-Exo promoted the migration, mineralization, and expression of bone-related genes such as alkaline phosphatase (ALP), bone morphogenetic protein 2 (BMP2), osteocalcin (OCN), and osteopontin (OPN) in human osteoblast-like cells. Furthermore, in vivo results showed that more newly formed bone was observed in the HPDLSCs-Exo-treated group than in the non-treated group at the defect sites in rats. These results indicated that HPDLSCs-Exo could promote osteogenesis in vitro and in vivo, and this suggests that HPDLSCs-Exo may be an attractive treatment tool for bone healing in defective periodontal tissue.

Exosomes to exosome-functionalized scaffolds: a novel approach to stimulate bone regeneration

Bone regeneration is a complex biological process that relies on the orchestrated interplay of various cellular and molecular events. Bone tissue engineering is currently the most promising method for treating bone regeneration. However, the immunogenicity, stable and cell quantity of seed cells limited their application. Recently, exosomes, which are small extracellular vesicles released by cells, have been found to effectively address these problems and better induce bone regeneration. Meanwhile, a growing line of research has shown the cargos of exosomes may provide effective therapeutic and biomarker tools for bone repair, including miRNA, lncRNA, and proteins. Moreover, engineered scaffolds loaded with exosomes can offer a cell-free bone repair strategy, addressing immunogenicity concerns and providing a more stable functional performance. Herein, we provide a comprehensive summary of the role played by scaffolds loaded with exosomes in bone regeneration, drawing on a systematic analysis of relevant literature available on PubMed, Scopus, and Google Scholar database.

Electron-donable heterojunctions with synergetic Ru-Cu pair sites for biocatalytic microenvironment modulations in inflammatory mandible defects

The clinical treatments of maxillofacial bone defects pose significant challenges due to complex microenvironments, including severe inflammation, high levels of reactive oxygen species (ROS), and potential bacterial infection. Herein, we propose the de novo design of an efficient, versatile, and precise electron-donable heterojunction with synergetic Ru-Cu pair sites (Ru-Cu/EDHJ) for superior biocatalytic regeneration of inflammatory mandible defects and pH-controlled antibacterial therapies. Our studies demonstrate that the unique structure of Ru-Cu/EDHJ enhances the electron density of Ru atoms and optimizes the binding strength of oxygen species, thus improving enzyme-like catalytic performance. Strikingly, this biocompatible Ru-Cu/EDHJ can efficiently switch between ROS scavenging in neutral media and ROS generation in acidic media, thus simultaneously exhibiting superior repair functions and bioadaptive antibacterial properties in treating mandible defects in male mice. We believe synthesizing such biocatalytic heterojunctions with exceptional enzyme-like capabilities will offer a promising pathway for engineering ROS biocatalytic materials to treat trauma, tumors, or infection-caused maxillofacial bone defects.

The Exosome-Mediated Bone Regeneration: An Advanced Horizon Toward the Isolation, Engineering, Carrying Modalities, and Mechanisms

Exosomes, nanoparticles secreted by various cells, composed of a bilayer lipid membrane, and containing bioactive substances such as proteins, nucleic acids, metabolites, etc., have been intensively investigated in tissue engineering owing to their high biocompatibility and versatile biofunction. However, there is still a lack of a high-quality review on bone defect regeneration potentiated by exosomes. In this review, the biogenesis and isolation methods of exosomes are first introduced. More importantly, the engineered exosomes of the current state of knowledge are discussed intensively in this review. Afterward, the biomaterial carriers of exosomes and the mechanisms of bone repair elucidated by compelling evidence are presented. Thus, future perspectives and concerns are revealed to help devise advanced modalities based on exosomes to overcome the challenges of bone regeneration. It is totally believed this review will attract special attention from clinicians and provide promising ideas for their future works.