Stem-cell-derived extracellular vesicles (EVs) have emerged as a promising therapeutic option, addressing the limitations of conventional stem cell therapies. However, the variability and poorly defined therapeutic contents of EVs produced under standard 2-dimensional culture conditions present challenges for their clinical application. In this study, we investigated how the therapeutic properties of mesenchymal stem cell (MSC)-derived EVs can be enhanced by culturing MSCs within 3-dimensional hydrogels that have tunable mechanical properties. Our results demonstrate that different mechanical cues from the culture environment can induce specific gene expression changes in MSCs without compromising their inherent characteristics. Furthermore, EVs derived from these MSCs exhibited distinct angiogenic and immunomodulatory activities, which were dependent on the mechanical properties of the hydrogels used. A comprehensive analysis of the cytokines and microRNAs present in the EVs provided additional validation of these findings. By utilizing a noninvasive culture method that eliminates the need for genetic modification or exogenous biochemical supplementation, our approach presents a novel platform for the tailored production of EVs, thereby enhancing their therapeutic potential in regenerative medicine.

Osteoporosis is a systemic metabolic degenerative bone disease characterised by decreased bone mass, impaired bone microstructure, weakened bone strength and susceptibility to fracture. In China, the prevention and treatment of osteoporosis is faced with a high disease prevalence rate but low awareness, diagnosis and treatment rates. Bone resorption inhibitors and bone formation promoters often dominate osteoporosis treatment. Although conventional drugs can alleviate symptoms and reduce fracture risk, they often come with musculoskeletal, allergic and digestive side effects. Natural traditional Chinese medicine (TCM) products, known for their multi-targeting, high safety, efficacy and low cost, have been widely used in the treatment and prevention of osteoporosis in recent years and have gradually been recognised by many experts locally and abroad. This paper summarises recent research progress on natural TCM products in preventing and treating osteoporosis and provides a theoretical and experimental basis for the development of new drugs and the improvement of osteoporosis management.

Histone lysine demethylases (KDMs), as important epigenetic regulators, are involved in various biological processes such as energy metabolism, apoptosis, and autophagy. Recent research shows that KDMs activate or silence downstream target genes by removing lysine residues from histone tails, and participate in the regulation of bone marrow mesenchymal stem cells (BM-MSCs), osteoblasts (OB), osteoclasts (OC), chondrocytes and other skeletal cell development, differentiation and formation. Moreover, several members of the KDM family affect the occurrence and development of bone diseases such as osteoporosis (OP), osteoarthritis (OA), osteosarcoma (OS), by regulating target genes. Specific regulation mechanisms of KDMs suggest new strategies for bone disease treatment and prevention. Despite the unique function and importance of KDMs in the skeletal system, previous studies have never systematically summarized their specific role, molecular mechanism, and clinical treatment in bone physiology and pathology. Therefore, this review summarises the expression pattern, intracellular signal transduction, and mechanism of action of the KDM family in several bone physiological and pathological conditions, aiming to highlight the important role of KDMs in bone diseases and provide a reference for the future treatment of bone diseases.

 The mechanical stimulation known as orthodontic mechanical force (OMF) causes biological reactions in orthodontic tooth movement (OTM). Heat shock protein-70 (HSP-70) needs pro-inflammatory cytokines to trigger bone resorption in OTM; nevertheless, heat shock protein-10 (HSP-10), a "Alarmin" cytokine, should control these pro-inflammatory cytokines to get the best alveolar bone remodeling (ABR). Moringa oleifera L. nanosuspension extract (MONE) has anti-inflammatory, antioxidant, and ABR-stimulating properties. The aim of the study was to examine in vivo HSP-10 and HSP-70 expressions under OMF following MONE application in Wistar rats (Rattus norvegicus).

 A total of 36 Wistar rats (R. norvegicus) were split up into eight groups: one for treatment (OMF + MONE) and one for control (OMF + MONE administration for days 1, 7, 14, and 21). By employing nickel-titanium coil springs and using 10 g of light force per millimeter to implant the orthodontic device, the OMF was completed. According to the day of observation, all of the samples were sacrificed. To perform an immunohistochemistry investigation, the premaxilla of the sample was isolated. Tukey's Honest Significant Different (HSD) test (p < 0.05) was performed after an Analysis of Variance (ANOVA) analysis of the data.

 In both the OMF and MONE groups, HSP-70 peaked on day 14 and began to fall on day 21. HSP-10 peaked on day 21, but along with MONE, it also began to progressively decline on days 14 and 21, with significant differences (p < 0.05).

 According to immunohistochemistry evidence, postadministration of MONE markedly elevated HSP-10 but lowered HSP-70 expression in the alveolar bone of Wistar rats under OMF.

Cutaneous scarring typically arises after surgery, trauma, and infection, occurring when normal skin tissue is replaced by fibrous tissue during the healing process. Myofibroblasts have been identified as a significant contributor to this scarring. While the differentiation of fibroblasts into myofibroblasts is well-recognized as essential for wound healing and tissue repair, the mechanisms underlying the macrophage-myofibroblast transition (MMT) remain largely unexplored. This study aimed to investigate the role and potential mechanisms of MMT in cutaneous scarring. In specimens of hypertrophic scars, keloid and scleroderma, we confirmed the coexistence of MMT markers CD68 and α-smooth muscle actin (α-SMA) in areas of skin fibrosis. Additionally, most MMT cells in human cutaneous scar co-expressed the M2-type macrophage marker CD206. Fate-mapping in Lyz2-Cre/Rosa26-tdTomato mice further demonstrated that the majority of myofibroblasts in cutaneous scars were derived from bone marrow macrophages. Furthermore, higher levels of TGF-β were released from scar fibroblasts, which contributed to MMT through the Smad3 pathways. In vivo studies inhibiting Smad3 reduced MMT and scarring. Macrophage depletion with clodronate liposomes also reduced cutaneous scar formation. Our findings indicate that MMT plays a pivotal role in cutaneous scarring through the TGF-β/Smad3 pathways. Consequently, inhibiting MMT may be a novel strategy for the treatment of cutaneous scarring.

Tooth root development is a complex process essential for tooth function, yet the role of root dentin development in tooth morphogenesis is not fully understood. Optineurin (OPTN), linked to bone disorders like Paget's disease of bone (PDB), may affect tooth root development. In this study, we used single-cell sequencing of embryonic day 16.5 (E16.5), postnatal day 1 (P1), and P7 mouse teeth, as well as embryonic and adult human teeth, to show that OPTN is vital for odontoblastic differentiation. In Optn-/- mice, we observed short root deformities and defective dentin, with impaired apical papilla differentiation and increased apoptosis. In vitro OPTN downregulation in stem cells of the apical papilla (SCAPs) exacerbated apoptosis and hindered odontoblastic differentiation. RNA-seq analysis revealed significant differences in mitochondrial dynamics between control and OPTN knockout SCAPs. We discovered that OPTN influences mitochondrial dynamics primarily by promoting fission, leading to odontoblastic differentiation and mineralisation. Mechanistically, OPTN cooperates with NRF2 to regulate mitochondrial fission via DRP1 phosphorylation and affects the transcription of BCL2. Rescue experiments using an activator of NRF2 in ex vivo organ cultures and local gingival injection experiments confirmed these findings. Therefore, we concluded that OPTN, interacting with NRF2, acts as a key regulator of SCAPs mitochondrial dynamics, mineralisation and apoptosis during tooth development. These findings provide fresh insights into the mechanisms underlying tooth root development.

Osteoporosis (OP), a systemic bone disease characterised by increased bone fragility and susceptibility to fracture, is mainly caused by a decline in bone mineral density (BMD) and quality caused by an imbalance between bone formation and resorption. Protein arginine methyltransferases (PRMTs) are epigenetic factors and post-translational modification (PTM) enzymes participating in various biological processes, including mRNA splicing, DNA damage repair, transcriptional regulation, and cell signalling. They act by catalysing the transfer and modification of arginine residues and, thus, have become therapeutic targets for OP. In-depth studies have found that these enzymes also play key roles in bone matrix protein metabolism, skeletal cell proliferation and differentiation, and signal pathway regulation to regulate bone formation, bone resorption balance, or both and jointly maintain bone health and stability. However, the expression changes and mechanisms of action of multiple members of the PRMT family differ in OP. Therefore, this paper discusses the biological functions, mechanisms of action, and influencing factors of PRMTs in OP, which is expected to provide a new understanding of the pathogenesis of OP. Furthermore, we present theoretical support for the development of more precise and effective treatment strategies as well as for further study of the molecular mechanisms of PRMTs.

Ellagic acid (EA) is a potent antioxidant that reduces oxidative stress and promotes differentiation. By lowering the harmful levels of reactive oxygen species (ROS), EA fosters an environment conducive to the osteoblastic differentiation (OB) of stem cells. In addition, it promotes autophagy and mitophagy, which are vital for promoting differentiation. Effective autophagic activity recycles damaged organelles and proteins, meeting the energy required during differentiation and shielding from apoptosis. However, molecular mechanisms underlying the osteogenic differentiation of mesenchymal stem cells remain inadequately explored. Therefore, the current study aims to define the regulatory role of EA during the OB of dental pulp-derived stem cells (DPSC) and to study how autophagy and mitophagy are being modulated during this differentiation process. Herein, we showed that the expression level of osteoblast-specific markers, autophagy, and mitophagy-associated markers was significantly elevated during EA-mediated OB differentiation of DPSC. Moreover, we found that the EA induced the osteoblastic-specific markers through canonical BMP2 pathway molecules, reduced ROS in both basal and activated states, and induced autophagy and mitophagy molecules along with enhanced mitochondrial functions. Cell cycle analysis revealed that the G1 phase was arrested via phosphorylation of γ-H2AX, ATM, and CHK2 proteins. Furthermore, in silico analysis revealed that EA strongly binds with osteonectin, a crucial noncollagen protein involved in bone remodeling, and confirmed by Western blot analysis. These results support that EA could be a promising natural compound for bone repair and regeneration applications.

Mutations in LMNA cause multiple types of muscular dystrophy (LMNA-MD). The symptoms of LMNA-MD are highly variable and sensitive to genetic background. To identify genetic contributions to this phenotypic variability, we performed whole-genome sequencing on four siblings possessing the same LMNA mutation with differing degrees of skeletal muscle disease severity. We identified a variant in SMAD7 that segregated with severe muscle disease. To functionally test the SMAD7 variant, we generated a Drosophila model possessing the LMNA mutation and the SMAD7 variant in the orthologous fly genes. The SMAD7 variant increased SMAD signaling and enhanced muscle defects caused by the mutant lamin. Conversely, overexpression of wild-type SMAD7 rescued muscle function. These findings were extended to humans by showing that SMAD signaling is increased in muscle biopsy tissue from individuals with LMNA-MD compared to age-matched controls. Collectively, our findings support SMAD7 as the first functionally tested genetic modifier for LMNA-MD and suggest components of the SMAD pathway as therapeutic targets.

Mesenchymal stem cells (MSCs) play a crucial role in bone formation and remodeling. Intrinsic genetic factors and extrinsic environmental cues regulate their differentiation into osteoblasts. Within the bone microenvironment, a complex network of biochemical and biomechanical signals orchestrates bone homeostasis and regeneration. In addition, the crosstalk among MSCs, immune cells, and neighboring cells-mediated by extracellular vesicles and non-coding RNAs (such as circular RNAs and micro RNAs) -profoundly influences osteogenic differentiation and bone remodeling. Recent studies have explored specific signaling pathways that contribute to effective bone regeneration, highlighting the potential of manipulating the bone microenvironment to enhance MSC functionality. The integration of advanced biomaterials, gene editing techniques, and controlled delivery systems is paving the way for more targeted and efficient regenerative therapies. Furthermore, artificial intelligence could improve bone tissue engineering, optimize biomaterial design, and enable personalized treatment strategies. This review explores the latest advancements in bone regeneration, emphasizing the intricate interplay among stem cells, immune cells, and signaling molecules. By providing a comprehensive overview of these mechanisms and their clinical implications, we aim to shed light on future research directions in this rapidly evolving field.

Osteogenesis is the process of bone formation mediated by the osteoblasts, participating in various bone-related physiological processes including bone development, bone homeostasis and fracture healing. It exhibits temporal and spatial interconnectivity with angiogenesis, constructed by multiple forms of cell communication occurring between bone and vascular endothelial cells. Molecular regulation among different cell types is crucial for coordinating osteogenesis and angiogenesis to facilitate bone remodeling, fracture healing, and other bone-related processes. The transmission of signaling molecules and the activation of their corresponding signal pathways are indispensable for various forms of cell communication. This communication acts as a "bridge" in coupling osteogenesis to angiogenesis. This article reviews the modes and processes of cell communication in osteogenesis-angiogenesis coupling over the past decade, mainly focusing on interactions among bone-related cells and vascular endothelial cells to provide insights into the mechanism of cell communication of osteogenesis-angiogenesis coupling in different bone-related contexts. Moreover, clinical relevance and applications are also introduced in this review.

Chronic degenerative changes in cartilage and subchondral bone that lead to instability of the cartilage microenvironment are essential for the development of osteoarthritis (OA) in the old. Synchronous repair of cartilage and subchondral bone may be a key strategy for OA treatment. PDGF-BB effectively promoted chondrocyte regeneration and angiogenesis. However, the mechanisms by which PDGF-BB affects subchondral bone and the delivery of PDGF-BB to the joint cavity need to be further explored. In this study, we used sodium hyaluronate to deliver PDGF-BB (SH-PDGF) to the joint space and aimed to determine the mechanisms of SH-PDGF in repairing cartilage and subchondral bone and stabilising the cartilage microenvironment. In this research, we determined the pharmacokinetics of PDGF-BB and SH-PDGF in cartilage. Moreover, we investigated the effects of PDGF-BB and SH-PDGF on cartilage and the subchondral bone microenvironment by identifying changes in the HIF-VEGF-Notch axis and SDF-1-CXCR4 axis in an OA rat model. The results showed that PDGF-BB increased cell viability, decreased HIF-1α levels, inhibited inflammation and improved matrix metabolism in osteoarthritic chondrocytes under hyperoxic or hypoxic conditions. We also found that PDGF-BB and SH-PDGF showed similar effects on repairing cartilage and subchondral bone simultaneously. However, SH-PDGF had some advantages over PDGF-BB in prolonging the injection interval and decreasing the injection time. These protective effects were mediated by the inhibition of both the HIF-1α-VEGF-Notch axis and the SDF-1-CXCR4 axis. The underlying mechanisms include the inhibition of HIF-1α-VEGF-Notch-mediated vessel invasion and SDF-1-CXCR4 axis-mediated crosstalk between cartilage and subchondral tissue.

Tendon injuries remains a challenge to treat owing to its poor intrinsic reparative ability. It is hypothesised that hypoxic conditioning of mesenchymal stem cells (MSC) through the activation of hypoxia-inducible factor-1 alpha (HIF-1α), may enhance tendon repair process by promoting cellular proliferation and tenogenic differentiation. To demonstrate this, a study using roxadustat, a specific hypoxia mimetic mediator and HIF-1α inducer was conducted on adipose-derived mesenchymal stromal cells (AD-MSCs). Cellular morphology, proliferation rates, tenogenic protein and gene expression levels in untreated AD-MSCs (Group 1), roxadustat pre-conditioned AD-MSCs (Group 2), AD-MSCs subjected to CAY10585 (Group 3), roxadustat pre-conditioned AD-MSCs with CAY10585 (Group 4) and untreated primary tenocytes (Group 5) were evaluated. MSCs pre-conditioned with 12.5µM roxadustat for 24 hours showed the highest expression of HIF-1α without affecting the proliferation rates of AD-MSCs. However, significant reduction of HIF-1α levels was observed when the cells were treated with 3.5µM CAY10585. Roxadustat significantly up-regulated collagen I and III expressions by 6.6 and 6.3-fold respectively. HIF-1α promoted Scleraxis, Tenascin-C and Collagen III expressions, resulting in an increase of 6, 7, and 3 folds respectively. Conversely, using CAY10585 reduced these expressions to 3, 2 and 1 folds respectively. These trends were observed in the gene expression levels across Groups 1 to 4. However, the expression of these genes in Group 2 was significantly lower as compared to Group 5. Conclusion: HIF-1α accumulation promotes superior cell proliferation and tenogenic differentiation of AD-MSCs, indicating that roxadustat may be a potential therapeutic mediator in tendon repair strategies.

The treatment of tendon/ligament-to-bone injury is a long-standing research challenge in orthopedics and bone tissue engineering. Orderly healing of the fibrocartilage layer and mineralized bone layer is crucial for treating tendon-bone interface injuries. We designed a three-dimensional printed porous titanium scaffold composite system with thermosensitive collagen hydrogel loaded with transforming growth factor β3 (TGF-β3), formulated for the sustained slow release of TGF-β3 at a constant rate. In vitro, the composite system exhibited good biocompatibility and was beneficial for the adhesion and proliferation of bone marrow mesenchymal stem cells (BMSCs), which showed high growth activity. Moreover, the composite system promoted the differentiation of BMSCs via osteogenesis and chondrogenesis. In vivo, the composite system provided active substances at the injured site, promoting the repair of the fibrocartilage layer and of the mineralized bone layer at the interface between the ligament and bone. Micro-CT results demonstrated that the complex promotes the osseointegration of titanium scaffolds in bone defects. Hard tissue sections showed that the new bone, ligament, and the titanium alloy scaffold system formed a closely integrated whole; the composite system provided suitable attachment points for ligament growth. Additionally, the biomechanical strength of the tendon interface improved to some extent. Our results indicate that the composite system has potential as a bioactive implant interface for repairing ligament and bone injuries.

The increasing incidence of bone diseases has driven research towards Bone Tissue Engineering (BTE), an innovative discipline that uses biomaterials to develop three-dimensional (3D) scaffolds capable of mimicking the natural environment of bone tissue. Traditional approaches relying on two-dimensional (2D) models have exhibited significant limitations in simulating cellular interactions and the complexity of the bone microenvironment. In response to these challenges, 3D models such as organoids and cellular spheroids have emerged as effective tools for studying bone regeneration. Adult mesenchymal stem cells have proven crucial in this context, as they can differentiate into osteoblasts and contribute to bone tissue repair. Furthermore, the integration of composite biomaterials has shown substantial potential in enhancing bone healing. Advanced technologies like microfluidics offer additional opportunities to create controlled environments for cell culture, facilitating more detailed studies on bone regeneration. These advancements represent a fundamental step forward in the treatment of bone pathologies and the promotion of skeletal health. In this review, we report on the evolution of in vitro culture models applied to the study of bone healing/regrowth, starting from 2 to 3D cultures and microfluids. The different methodologies of in vitro model generation, cells and biomaterials are presented and discussed.

Recent advancements in tissue engineering and stem cell science have positioned bone disease treatment as a promising frontier in regenerative medicine. This review explores the hormonal and signaling pathways critical to bone regeneration, with a focus on their clinical relevance. Key endocrine factors, including thyroid hormones (T3 and T4), insulin-like growth factor 1 (IGF-1), bone morphogenetic proteins (BMPs), parathyroid hormone (PTH), calcitonin, and fibroblast growth factor 23 (FGF23), play pivotal roles in bone remodeling by regulating osteoblast activity, bone resorption, and mineralization. These factors primarily act through the Wnt/β-catenin, BMP, and FGF signaling pathways, which govern bone repair and regeneration. While animal models, such as axolotls, zebrafish, and Xenopus laevis, provide valuable findings about these mechanisms, translating these findings into human applications presents challenges. This review underscores the therapeutic potential of modulating these hormonal networks to enhance bone regeneration while cautioning against possible adverse effects, such as uncontrolled tissue proliferation or metabolic imbalances. By integrating knowledge from regenerative models, this work provides a foundation for optimizing hormone-based therapies for clinical applications in bone repair and disease treatment.

SMAD2 is a coregulator that binds a variety of transcription factors in human development. Heterozygous SMAD2 loss-of-function and missense variants are identified in patients with congenital heart disease (CHD) or arterial aneurysms. Mechanisms that cause distinct cardiovascular phenotypes remain unknown. We aimed to define transcriptional and epigenetic effects of SMAD2 variants and their role in CHD. We also assessed the function of SMAD2 missense variants of uncertain significance.

Rare SMAD2 variants (minor allele frequency ≤10-5) were identified in exome sequencing of 11 336 participants with CHD. We constructed isogenic induced pluripotent stem cells with heterozygous or homozygous loss-of-function and missense SMAD2 variants identified in CHD probands. Wild-type and mutant induced pluripotent stem cells were analyzed using bulk RNA sequencing, chromatin accessibility (Assay for Transposase-Accessible Chromatin With Sequencing), and integrated with published SMAD2/3 chromatin immunoprecipitation data. Cardiomyocyte differentiation and contractility were evaluated. Thirty participants with CHD had heterozygous loss-of-function or missense SMAD2 variants. SMAD2 haploinsufficiency altered chromatin accessibility at promoters and dysregulated expression of 385 SMAD regulated genes, including 10 CHD-associated genes. Motifs enriched in differential Assay for Transposase-Accessible Chromatin peaks predicted that SMAD2 haploinsufficiency disrupts interactions with transcription factors NANOG (homeobox protein NANOG), ETS, TEAD3/4 (transcriptional enhanced associate domain 3/4), CREB1 (cAMP response element binding protein 1), and AP1 (activator protein 1). Compared with SMAD2-haploinsufficient cells, induced pluripotent stem cells with R114C or W274C variants exhibited distinct and shared chromatin accessibility and transcription factor binding changes.

SMAD2 haploinsufficiency disrupts transcription factor binding and chromatin interactions critical for cardiovascular development. Differences between the molecular consequences of loss-of-function and missense variants likely contribute to phenotypic heterogeneity. These findings indicate opportunities for molecular analyses to improve reclassification of SMAD2 variants of uncertain clinical significance.

With the advancement of medical technology, the utilization of bioactive materials to promote bone repair has emerged as a significant research area. Hydrogels, as biomaterials, play a crucial role in bone tissue engineering. These hydrogels exhibit high biocompatibility, providing in vivo ecological conditions conducive to cell survival, and offer substantial advantages in facilitating bone repair. Different matrices of hydrogels serve distinct functions. In recent years, numerous researchers have developed a variety of novel hydrogel materials utilizing diverse matrices. These materials not only enhance the osteogenic induction capacity of hydrogels but also improve their efficacy as scaffolds in the treatment of complex bone defects, such as those resulting from trauma, tumor resection, or large bone defects due to infection. This article primarily analyzes the role of hydrogels that utilize polysaccharides and polymers as matrices in bone tissue repair, focusing on the creation of an optimal microenvironment to promote bone regeneration. These investigations deepen the understanding of the mechanisms underlying the action of hydrogels and establish a foundation for future advancements in the biomedical field.

Our previous study showed that acidic stimuli activate acid-sensitive ion channel 1a (ASIC1a), resulting in chondrocyte destruction associated with rheumatoid arthritis (RA). However, the exact underlying processes remain unclear. Recent evidence suggests that the production of reactive oxygen species (ROS) mediated by succinate dehydrogenase (SDH), contributes to chondrocyte damage. The objective of this study was to investigate the involvement of SDH in ASIC1a-induced chondrocyte destruction in RA and to explore the associated mechanisms both in vivo and in vitro. Our findings revealed that the cartilage of mice with collagen-induced arthritis (CIA) and acid-treated chondrocytes exhibited a substantial increase in SDH expression. Furthermore, SDH inhibition attenuates acidosis-induced pyroptosis in chondrocytes. Notably, ASIC1a activation through acid stimuli increases SDH activity and pyroptosis through the Ca2+/CaMKK2/AMPK pathway in chondrocytes. Mechanistically, SDH assembly factor 2 (SDHAF2) was identified as a key modulator of SDH activity induced by ASIC1a in acid-stressed chondrocytes. Moreover, the expression of SDH in CIA mouse chondrocytes decreased and the histological characteristics of ankle joint damage were reduced by the ASIC1a-particular blocker PcTx-1. Overall, these observations suggest that ASIC1a activation under acidic conditions increases SDH activity and modulates SDHAF2, thereby promoting chondrocyte pyroptosis through the Ca2+/CaMKK2/AMPK pathway.

Biodegradable scaffolds, including metals, ceramics, and polymers, show great potential in bone tissue regeneration. However, current biodegradable scaffolds do not simultaneously possess suitable mechanical properties, biodegradability and osteoinductivity, which severely limits their clinical application for large segmental bone defect repair. Herein, we developed a biomimetic and hierarchically micro-nanoporous iron-based scaffold utilizing a synergistic approach combining 3-dimensional printing, surface dealloying treatment and electrochemical deposition. Compared to traditional periodic lattice structures, the biomimetic scaffold with a stochastic lattice structure promised superior stress transfer efficiency. Cell experiments revealed that the biomimetic scaffold notably enhanced osteogenesis and angiogenesis in vitro via EGFR-mediated Ras/Raf/MAPK signaling. Upon implantation in a rat femoral condyle defect model, the scaffold achieved a dynamic equilibrium between in vivo material degradation and bone formation. More importantly, the study conducted in a large animal model with an extended cycle of up to 1 year demonstrated that bionic iron-based scaffolds effectively facilitated the repair and functional reconstruction of large bone defects in load-bearing regions by inducing vascularized bone regeneration. This study not only introduces a potential solution for addressing critical-sized bone defects in load-bearing regions but also provides a viable approach for the design of other biomimetic biomaterials.

Currently, bone tissue engineering is a research hotspot in the treatment of orthopedic diseases, and many problems in orthopedics can be solved through bone tissue engineering, which can be used to treat fractures, bone defects, arthritis, etc. More importantly, it can provide an alternative to traditional bone grafting and solve the problems of insufficient autologous bone grafting, poor histocompatibility of grafts, and insufficient induced bone regeneration. Growth factors are key factors in bone tissue engineering by promoting osteoblast proliferation and differentiation, which in turn increases the efficiency of osteogenesis and bone regeneration. 3D printing technology can provide carriers with better pore structure for growth factors to improve the stability of growth factors and precisely control their release. Studies have shown that 3D-printed scaffolds containing growth factors provide a better choice for personalized treatment, bone defect repair, and bone regeneration in orthopedics, which are important for the treatment of orthopedic diseases and have potential research value in orthopedic applications. This paper aims to summarize the research progress of 3D printed scaffolds containing growth factors in orthopedics in recent years and summarize the use of different growth factors in 3D scaffolds, including bone morphogenetic proteins, platelet-derived growth factors, transforming growth factors, vascular endothelial growth factors, etc. Optimization of material selection and the way of combining growth factors with scaffolds are also discussed.

The differentiation of human induced pluripotent stem cells (hiPSCs) into neural progenitor cells (NPCs) is a promising approach for the treatment of neurodegenerative diseases and regenerative medicine. Dual-SMAD inhibition using small molecules has been identified as a key strategy for directing the differentiation of hiPSCs into NPCs by regulating specific cell signaling pathways. However, conventional culture methods are time-consuming and exhibit low differentiation efficiency in neural differentiation. Nanocarriers can address these obstacles as an efficient platform for the controlled release and accurate delivery of small molecules. In this paper, we developed calcium phosphate-coated mesoporous silica nanoparticles capable of delivering multiple small molecules, including LDN193189 as a bone morphogenetic protein (BMP) inhibitor and SB431542 as a transforming growth factor (TGF)-beta inhibitor, for direct differentiation of hiPSC-mediated NPCs. Our results demonstrated that this nanocarrier-mediated small molecule release system not only enhanced the in vitro formation of neural rosettes but also modulated the expression levels of key markers. In particular, it downregulated OCT4, a marker of pluripotency, while upregulating PAX6, a critical marker for the neuroectoderm. These findings suggest that this controlled small molecule release system holds significant potential for therapeutic applications in neural development and neurodegenerative diseases.

Polycystic ovary syndrome (PCOS) is a prevalent disorder of the endocrine system with significant clinical implications, often leading to health complications related to adipose tissue accumulation, including obesity, insulin resistance (IR), metabolic syndrome, and type 2 diabetes mellitus. While the precise pathogenesis of PCOS remains unclear, it is now recognized that genetic, endocrine, and metabolic dysregulations all contribute significantly to its onset. The immunopathogenesis of PCOS has not been extensively explored, but there is growing speculation that immune system abnormalities may play a pivotal role. This chronic inflammatory state is exacerbated by factors such as obesity and hyperinsulinemia. Therefore, this review aims to elucidate the interplay between IR in PCOS patients, the controlled immune response orchestrated by immune cells and immunomodulatory molecules, and their interactions with adipocytes, hyperandrogenemia, chronic inflammation, and metabolic homeostasis.

Indole-3-propionic acid (IPA), a metabolite produced by gut microbiota through tryptophan metabolism, has recently been identified as playing a pivotal role in bone metabolism. IPA promotes osteoblast differentiation by upregulating mitochondrial transcription factor A (Tfam), contributing to increased bone density and supporting bone repair. Simultaneously, it inhibits the formation and activity of osteoclasts, reducing bone resorption, possibly through modulation of the nuclear factor-κB (NF-κB) pathway and downregulation of osteoclast-associated factors, thereby maintaining bone structural integrity. Additionally, IPA provides indirect protection to bone health by regulating host immune responses and inflammation via activation of receptors such as the Aryl hydrocarbon Receptor (AhR) and the Pregnane X Receptor (PXR). This review summarizes the roles and signaling pathways of IPA in bone metabolism and its impact on various bone metabolic disorders. Furthermore, we discuss the therapeutic potential and limitations of IPA in treating bone metabolic diseases, aiming to offer novel strategies for clinical management.

This study aimed to investigate the effects of ginseng non-edible callus-derived extracellular vesicle (GNEV) on skin regeneration, particularly focusing on its impact on proliferation and migration in human dermal fibroblast (HDF).

GNEV was isolated from ginseng non-edible callus using sequential filtration and size exclusion chromatography (SEC). The extracellular vesicle was characterized using nanoparticle tracking analysis (NTA). HDF was treated with various concentrations of GNEV, and cell viability, proliferation, and migration were assessed using MTT and scratch wound healing assays. Gene expression related to collagen synthesis (TGF-β, SMAD-2, SMAD-3, COL1A1) was measured using RT-PCR.

Treatment of HDF with GNEV resulted in a significant 2.5-fold increase in cell migration compared to the non-treated group. Furthermore, GNEV demonstrated the upregulation of collagen synthesis genes, specifically TGF-β, SMAD-2, SMAD-3, and COL1A1, by 41.7 %, 59.4 %, 60.2 %, and 21.8 %, respectively. These findings indicated that GNEV activates the TGF-β/SMAD signaling pathway, showcasing its potential to induce skin regeneration.

In conclusion, GNEV exhibits a notable ability to enhance skin regeneration through its stimulatory effects on cell migration and the upregulation of key collagen synthesis genes. The activation of the TGF-β/SMAD signaling pathway further suggests the potential of GNEV as a promising candidate for drug delivery systems in the fields of cosmetics and pharmaceuticals, opening avenues for further research and application in skincare and dermatology.

Postmenopausal osteoporosis (PMOP) is a chronic systemic bone metabolism disorder. Promotion in the patterns of human bone marrow mesenchymal stem cells (hBMSCs) differentiation towards osteoblasts contributes to alleviating osteoporosis. Aucubin, a natural compound isolated from the well-known herbal medicine Eucommia, was previously shown to possess various pharmacological effects. However, its effects on hBMSCs of PMOP patients are unknown. The aim of this present research was to investigate the impact and underlying process of aucubin on cell proliferation and osteogenic differentiation in hBMSCs isolated from PMOP patients. The ability of aucubin to inhibit the ferroptosis induced by erastin in hBMSCs was detected; ROS production, ferrous ion levels, SOD, MDA, and GPX activities were tested by using commercial kits. Next, ALP staining, ARS staining, RT-qPCR, RNA-sequencing, and Western blot were applied for determining the mRNA and protein expression levels associated with the osteogenesis of hBMSCs. The study also explored the involvement of BMP2/Smads signalling in aucubin promoting the osteogenesis of hBMSCs and evaluated the effects of aucubin intervention on osteoporosis using an ovariectomised rat model. The results indicated that aucubin significantly inhibited ROS generation and oxidative stress induced by erastin and protected against ferroptosis in hBMSCs. Additionally, aucubin facilitated osteogenic differentiation of hBMSCs by activating the BMP2/SMADs pathway and attenuated the progression of osteoporosis in OVX rats, suggesting a potential therapeutic benefit for postmenopausal osteoporosis (PMOP).

To investigate the genetic factors underlying marketed body size traits in Chinese local geese, we conducted a comprehensive study involving nine body size traits in 251 samples at 10 weeks of age from five local breeds: Taihu goose (TH), Sichuan goose (SC), Guangfeng goose (GF), Xupu goose (XP), and Youjiang goose (YJ). Genotyping data were obtained through whole-genome re-sequencing, followed by a genome-wide association analysis utilizing the fixed and random model circulating probability unification (FarmCPU) approach. Our findings revealed 88 significant SNPs associated with body size traits, with 16 SNPs surpassing the genome-wide significance threshold (p = 3.98E-09) and 72 SNPs exceeding the suggestive significance threshold (p = 5E-07). Subsequent gene annotation identified these SNPs to be located within exonic regions of 86 candidate genes, including THADA, ATP5A1, ZNF462, PRDM8, and GH14523. Notably, functional enrichment analysis employing Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways highlighted 37 significantly enriched pathways, among which the "negative regulation of transforming growth factor beta receptor signaling pathway" (GO:0030512) emerged as relevant to goose skeletal development and the phenotypic expression of body size in geese. The identification of these novel SNPs and candidate genes associated with 10-week-old body size traits in geese presents valuable insights for future molecular breeding endeavors and the elucidation of underlying mechanisms governing body size trait formation in goose.

Impaired bone healing following tooth extraction poses a significant challenge for implantation. As a crucial component of the natural immune system, the NLRP3 inflammasome is one of the most extensively studied pattern-recognition receptors, and is involved in multiple diseases. Yet, the role of NLRP3 in bone healing remains to be clarified. Here, to investigate the effect of NLRP3 on bone healing, we established a maxillary first molar extraction model in wild-type and NLRP3KO mice using minimally invasive techniques. We observed that NLRP3 was activated during the bone repair phase, and its depletion enhanced socket bone formation and osteoblast differentiation. Moreover, NLRP3 inflammasome activation was found to inhibit osteogenic differentiation in alveolar bone-derived mesenchymal stem cells (aBMSCs), an effect mitigated by NLRP3 deficiency. Mechanistically, we established that the SMAD2/3-RUNX2 signaling pathway is a downstream target of NLRP3 inflammasome activation, and SMAD2/3 knockdown partially reversed the significant decrease in expression of RUNX2, OSX, and ALP induced by NLRP3. Thus, our findings demonstrate that NLRP3 negatively modulates alveolar socket bone healing and contributes to the understanding of the NLRP3-induced signaling pathways involved in osteogenesis regulation.

Asthma is characterized by chronic bronchial inflammation and is a highly heterogeneous disease strongly influenced by both specific and non-specific exogenous factors. The present study was performed to assess the effect of nasal allergen provocation tests and methacholine provocation tests on the mRNA co-expression patterns of genes (SMAD1/3/6/7, MPK1/3 and TGFB1/3) involved in SMAD and non-SMAD TGF-β signaling pathways in patients with asthma. Reverse transcription-quantitative PCR was performed on blood samples taken pre-provocation and 1 h post-provocation to assess gene expression changes. Of the 59 patients studied, allergen provocations were administered to 27 patients and methacholine provocations to 32 patients. Correlations between expression levels of studied genes were found to be influenced markedly by the challenge administered, challenge test result and time elapsed since challenge. Importantly, increases in expression levels for four gene pairs (MAPK1-SMAD3, MAPK3-SMAD3, SMAD1-SMAD3 and SMAD3-TGFB1) were found to correlate significantly with asthma occurrence in the allergen provocation cohort, but not in the methacholine provocation cohort. The present study allows us to draw the conclusion that both intranasal allergen and bronchial methacholine challenges influence mRNA co-expression patterns of the SMAD1/3/6/7, MPK1/3 and TGFB1/3 genes.

During osteogenesis, a large number of bioactive molecules, macromolecules, cells, and cellular signals are activated to induce bone growth and development. The activation of molecular pathways leads to the occurrence of cellular events, ultimately resulting in observable changes. Therefore, in the studies of bone tissue engineering and regenerative medicine, it is essential to target fundamental events to exploit the mechanisms involved in osteogenesis. In this context, signaling pathways are activated during osteogenesis and trigger the activation of numerous other processes involved in osteogenesis. Direct influence of signaling pathways should allow to manipulate the signaling pathways themselves and impact osteogenesis. A combination of sequential cascades takes place to drive the progression of osteogenesis. Also, the occurrence of these processes and, more generally, cellular and molecular processes related to osteogenesis necessitate the presence of transcription factors and their activity. The present review focuses on outlining several signaling pathways and transcription factors influencing the development of osteogenesis, and describes various methods of their manipulation to induce and enhance bone formation.

Osteoporosis (OP) is a metabolic disease characterized by low bone mineral mass owing to osteoblast dysfunction. Eucommia ulmoides Oliver (EuO) is a Chinese herbal medicine traditionally used to treat OP. Here, a polysaccharide purified from the EuO cortex (EuOCP3) was administered to OP mice constructed with dexamethasone (Dex) to investigate its anti-OP activity. EuOCP3 significantly improved Dex-induced bone microarchitecture destruction, increased osteoblast numbers and surface, and stimulated an increase in the expression of osteoblast differentiation markers in the femurs of OP mice. Furthermore, EuOCP3 was applied to MC3T3-E1 cells to further explore its effects on osteoblast differentiation. EuOCP3 significantly promoted osteoblast differentiation and increased the level of phosphorylated extracellular signal-regulated kinase1/2 (ERK1/2) and SMAD1/5/8. The EuOCP3-mediated enhancement of osteoblast differentiation-related proteins and phosphorylated SMAD1/5/8 expression levels was strongly suppressed by an ERK inhibitor (PD98059), which confirmed the critical role of ERK signaling in EuOCP3-induced osteoblast differentiation. In summary, EuOCP3 can stimulate bone formation by improving osteoblast differentiation via ERK/BMP-2/SMAD signaling, indicating the potential use of EuOCP3 as a functional ingredient in food products for anti-OP treatment.

Wound regeneration with integral function and cutaneous appendages remains challenging in wound dressing applications. Cellulose nanofibers (CNF) exhibit remarkable characteristics in wound dressing applications; however, their utility in the wound healing process is limited by insufficient scar inhibition and regenerative healing. Herein, inspired by fibroblast heterogeneity mediating wound healing and skin regeneration, we developed a CNF scaffold designed to block Dipeptidyl Peptidase 4 positive (DPP4+) fibroblasts for regenerative healing. CNF encapsulated sitagliptin (SITA) and zinc sulfide nanoparticles (NZnS), namely CNF@SITA@NZnS, to fabricate a novel biomaterial for scar reduction and regenerative healing. The scaffold promoted scarless healing and hair follicle regeneration in rats. In vivo experiments, the wounds in the scaffold showed less skin fibrosis, a better collagen ratio and more new hair follicles. In vitro experiments showed that the scaffold material promoted scarless healing, possibly by inhibiting the secretion of extracellular matrix and fibroblast-to-myofibroblast conversion. The promotion of hair follicle regeneration by the scaffold material may be due to promotion of the migration and proliferation of human hair follicle papilla cells. RNA sequencing is performed to explore the underlying mechanisms, which can activate ECM-receptor interaction pathway in favor of the wound healing process. The inhibiting effect of CNF@SITA@NZnS scaffold on DPP4+ fibroblasts can be a potential target to reduce scarring and promote skin regeneration.

The gene inhibin subunit beta B (INHBB) encodes the inhibin βB subunit, which is involved in forming protein members of the transforming growth factor-β (TGF-β) superfamily. The TGF-β superfamily is extensively involved in cell proliferation, differentiation, adhesion, movement, metabolism, communication, and death. Activins and inhibins, which belong to the TGF-β superfamily, were first discovered in ovarian follicular fluid. They were initially described as regulators of pituitary follicle-stimulating hormone (FSH) secretion both in vivo and in vitro. Later studies found that INHBB is expressed not only in reproductive organs such as the ovary, uterus, and testis but also in numerous other organs, including the brain, spinal cord, liver, kidneys, and adrenal glands. This wide distribution implies its involvement in the normal physiological functions of various organs; however, the mechanisms underlying these functions have not yet been fully elucidated. Recent studies suggest that INHBB plays a significant, yet complex role in tumorigenesis. It appears to have dual effects, promoting tumor progression in some contexts while inhibiting it in others, although these roles are not yet fully understood. In this paper, we review the different expression patterns, functions, and mechanisms of INHBB in normal and tumor tissues to illustrate the research prospects of INHBB in tumor progression.

Osteoporosis (OP) is a prevalent skeletal disorder characterized by decreased bone mineral density (BMD) and increased fracture risk. The advancements in omics technologies-genomics, transcriptomics, proteomics, and metabolomics-have provided significant insights into the molecular mechanisms driving OP. These technologies offer critical perspectives on genetic predispositions, gene expression regulation, protein signatures, and metabolic alterations, enabling the identification of novel biomarkers for diagnosis and therapeutic targets. This review underscores the potential of these multi-omics approaches to bridge the gap between basic research and clinical applications, paving the way for precision medicine in OP management. By integrating these technologies, researchers can contribute to improved diagnostics, preventative strategies, and treatments for patients suffering from OP and related conditions.

Background/Objectives: Crude extracts from the Brassica genus have recently emerged as promising phytochemicals for preventing bone loss. While the most documented evidence suggests that their general biological activity is due to glucosinolates' (GLSs') hydrolysis products, the direct activity of GLSs is beginning to be uncovered. However, the contribution of GLSs to the bone-sparing activity of crude Brassicaceae extracts has seldom been addressed. Here, we aimed to gain insights into this gap by studying in the same in vitro model of human osteogenesis the effect of two Brassica seed extracts (Eruca sativa and Lepidium sativum) obtained from defatted seed meals, comparing them to the isolated GLSs most represented in their composition, glucoerucin (GER) and glucotropaeolin (GTL), for Eruca sativa and Lepidium sativum, respectively. Methods: Osteogenic differentiation of human mesenchymal stromal cells (hMSCs) was assessed by alizarin red staining assay and real-time PCR, respectively, evaluating mineral apposition and mRNA expression of specific osteogenic genes. Results: Both Brassica extracts and GLSs increased the osteogenic differentiation, indicating that the stimulating effect of Brassica extracts can be at least partially attributed to GLSs. Moreover, these data extend previous evidence of the effect of unhydrolyzed glucoraphanin (GRA) on osteogenesis to other types of GLSs: GER and GTL. Notably, E. sativa extract and GTL induced higher osteogenic stimulation than Lepidium sativum extract and GER, respectively. Conclusions: Overall, this study expands the knowledge on the possible application of Brassica-derived bioactive molecules as natural alternatives for the prevention and treatment of bone-loss pathologies.

The neuropeptide kisspeptin and its cognate receptor have been extensively studied in reproductive physiology, with diverse and well-established functions, including as an upstream regulator of pubertal onset, reproductive hormone secretion, and sexual behavior. Besides classical reproduction, both kisspeptin and its receptor are extensively expressed in bone-resorbing osteoclasts and bone-forming osteoblasts, which putatively permits direct bone effects. Accordingly, this sets the scene for recent compelling findings derived from in vitro experiments through to in vivo and clinical studies revealing prominent regulatory interactions for kisspeptin signaling in bone metabolism, as well as certain oncological aspects of bone metabolism. Herein, we comprehensively examine the experimental evidence obtained to date supporting the interaction between kisspeptin and bone. A comprehensive understanding of this emerging facet of kisspeptin biology is fundamental to exploiting the future therapeutic potential of kisspeptin-based medicines as a novel strategy for treating bone-related disorders.