Dynamics of Transcription Factors in Three Early Phases of Osteogenic, Adipogenic, and Chondrogenic Differentiation Determining the Fate of Bone Marrow Mesenchymal Stem Cells in Rats

Crosstalk Between Antioxidants and Adipogenesis: Mechanistic Pathways and Their Roles in Metabolic Health

The interplay between oxidative stress and adipogenesis is a critical factor in the development of obesity and its associated metabolic disorders. Excessive reactive oxygen species (ROS) disrupt key transcription factors such as peroxisome proliferator-activated receptor gamma (PPARγ) and CCAAT/enhancer-binding protein alpha (C/EBPα), impairing lipid metabolism, promoting adipocyte dysfunction, and exacerbating inflammation and insulin resistance. Antioxidants, classified as endogenous (e.g., glutathione, superoxide dismutase, and catalase) and exogenous (e.g., polyphenols, flavonoids, and vitamins C and E), are pivotal in mitigating these effects by restoring redox balance and preserving adipocyte functionality. Endogenous antioxidants neutralize ROS and safeguard cellular structures; however, under heightened oxidative stress, these defenses are often insufficient, necessitating dietary supplementation. Exogenous antioxidants derived from plant-based sources, such as polyphenols and vitamins, act through direct ROS scavenging, upregulation of endogenous antioxidant enzymes, and modulation of key signaling pathways like nuclear factor kappa B (NF-κB) and PPARγ, reducing lipid peroxidation, inflammation, and adipocyte dysfunction. Furthermore, they influence epigenetic regulation and transcriptional networks to restore adipocyte differentiation and limit lipid accumulation. Antioxidant-rich diets, including the Mediterranean diet, are strongly associated with improved metabolic health, reduced obesity rates, and enhanced insulin sensitivity. Advances in personalized antioxidant therapies, guided by biomarkers of oxidative stress and supported by novel delivery systems, present promising avenues for optimizing therapeutic interventions. This review, "Crosstalk Between Antioxidants and Adipogenesis: Mechanistic Pathways and Their Role in Metabolic Health", highlights the mechanistic pathways by which antioxidants regulate oxidative stress and adipogenesis to enhance metabolic health.

Novel Clinical Insights into the Pathogenesis of Posttraumatic Elbow Stiffness: An Expression Profile Analysis of Contracted Joint Capsule in Human

Background

Posttraumatic elbow stiffness is a complex complication with two characteristics of capsular contracture and heterotopic ossification. Currently, genomic mechanisms and pathogenesis of posttraumatic elbow stiffness remain inadequately understood. This study aims to identify differentially expressed genes (DEGs) and elucidate molecular networks of posttraumatic elbow stiffness, providing novel insights into disease mechanisms at transcriptome level.

Methods

Global transcriptome sequencing was conducted on six capsular samples from individuals with posttraumatic elbow stiffness and three control capsular samples from individuals with elbow fractures. Differentially expressed genes (DEGs), microRNAs, and long non-coding RNAs (LncRNAs) were identified and analyzed. Functional enrichment analysis was performed, and the associated protein-protein interaction (PPI) network was constructed. MicroRNAs targeting these DEGs were identified, and transcription factors (TFs) targeting DEGs were predicted using the ENCODE database. Finally, key DEGs were validated by quantitative real-time polymerase chain reaction (qRT-PCR).

Results

A total of 4909 DEGs associated with protein-coding, LncRNA and microRNA were detected, including 2124 upregulated and 2785 downregulated. Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis revealed that the DEGs were significantly enriched in 36 signaling pathways, notably involving inflammatory responses and extracellular matrix (ECM) receptor interactions. The protein-protein interaction (PPI) network analysis highlighted genes such as SPP1, IBSP, MMP13 and MYO1A as having higher degrees of connectivity. Key microRNAs (hsa-miR-186-5p, hsa-miR-515-5p, and hsa-miR-590-3p) and transcription factors (TFDP1 and STAT3) were predicted to be implicated in the pathogenesis of posttraumatic elbow stiffness through the microRNA-transcription factor regulatory network analysis.

Conclusion

The study provided insights into the molecular mechanisms underlying the changes in the contracted capsules associated with posttraumatic elbow stiffness. Hub genes including SPP1, IBSP, MMP13, and MYO1A, key microRNAs (has-miR-186-5p, has-miR-515-5p, hsa-miR-590-3p) and TFs (TFDP1 and STAT3) may serve as prognostic and therapeutic targets of posttraumatic elbow stiffness, and provide a new idea for the future research direction of clinical treatment.

Adapting to the acidic environment of the NP: RADA16-PLGA (TGF-β3) induces chondrogenic differentiation of BMSCs

Aim: RADA16-PLGA composite scaffolds constructed with simultaneous loading of BMSCs and TGF-β3 and explored their ability for chondrogenic differentiation in vitro.Methods: The performance of the composite scaffolds is assessed by rheometer assay, electron microscopic structural observation and ELISA release assay. The biosafety of the composite scaffolds is assessed by cytocompatibility assay and cell migration ability. The chondrogenic differentiation ability of composite scaffolds is evaluated by Alisin blue staining, PCR and immunofluorescence staining.Results: The composite scaffold has a good ECM-like structure, the ability to control the release of TGF-β3 and good biocompatibility. More importantly, the composite scaffolds can induce the differentiation of BMSCs to chondrocytes.Conclusion: Composite scaffolds are expected to enhance the endogenous NP repair process.

N6-Methyladenosine in Cell-Fate Determination of BMSCs: From Mechanism to Applications

The methylation of adenosine base at the nitrogen-6 position is referred to as "N6-methyladenosine (m6A)" and is one of the most prevalent epigenetic modifications in eukaryotic mRNA and noncoding RNA (ncRNA). Various m6A complex components known as "writers," "erasers," and "readers" are involved in the function of m6A. Numerous studies have demonstrated that m6A plays a crucial role in facilitating communication between different cell types, hence influencing the progression of diverse physiological and pathological phenomena. In recent years, a multitude of functions and molecular pathways linked to m6A have been identified in the osteogenic, adipogenic, and chondrogenic differentiation of bone mesenchymal stem cells (BMSCs). Nevertheless, a comprehensive summary of these findings has yet to be provided. In this review, we primarily examined the m6A alteration of transcripts associated with transcription factors (TFs), as well as other crucial genes and pathways that are involved in the differentiation of BMSCs. Meanwhile, the mutual interactive network between m6A modification, miRNAs, and lncRNAs was intensively elucidated. In the last section, given the beneficial effect of m6A modification in osteogenesis and chondrogenesis of BMSCs, we expounded upon the potential utility of m6A-related therapeutic interventions in the identification and management of human musculoskeletal disorders manifesting bone and cartilage destruction, such as osteoporosis, osteomyelitis, osteoarthritis, and bone defect.

The Function and Mechanism of Anti-Inflammatory Factor Metrnl Prevents the Progression of Inflammatory-Mediated Pathological Bone Osteolytic Diseases

Metrnl, recently identified as an adipokine, is a secreted protein notably expressed in white adipose tissue, barrier tissues, and activated macrophages. This adipokine plays a pivotal role in counteracting obesity-induced insulin resistance. It enhances adipose tissue functionality by promoting adipocyte differentiation, activating metabolic pathways, and exerting anti-inflammatory effects. Extensive research has identified Metrnl as a key player in modulating inflammatory responses and as an integral regulator of muscle regeneration. These findings position Metrnl as a promising biomarker and potential therapeutic target in treating inflammation-associated pathologies. Despite this, the specific anti-inflammatory mechanisms of Metrnl in immune-mediated osteolysis and arthritis remain elusive, warranting further investigation. In this review, we will briefly elaborate on the role of Metrnl in anti-inflammation function in inflammation-related osteolysis, arthritis, and pathological bone resorption, which could facilitate Metrnl's clinical application as a novel therapeutic strategy to prevent bone loss. While the pathogenesis of elbow stiffness remains elusive, current literature suggests that Metrnl likely exerts a pivotal role in its development.

A 14-bp deletion in bovine EPAS1 gene is associated with carcass traits

EPAS1 (Endothelial PAS Domain Protein 1) gene is well-known for its function in plateau hypoxia adaptability. It encodes HIF-2α, which involved in the induction of genes regulated by oxygen and then affects multiple physiological processes such as angiogenesis and energy metabolism. All of these indicate it may affect the development of animals. In this study, a 14-bp deletion in EPAS1 gene was uncovered in Shandong black cattle population (n = 502). Two genotypes (II and ID) were found and the frequency of the homozygous II genotype is higher than the heterozygous ID genotype. This population is consisted with HWE (p > 0.05). And more importantly, the 14-bp deletion was associated with outside flat (p = 0.003), brisket (p = 0.001), and knuckle (p = 0.032). These findings suggested that the 14-bp deletion is significantly associated with carcass traits, which could be served as a molecular marker applied to cow breeding.

Cellular Alterations in Carbohydrate and Lipid Metabolism Due to Interactions with Nanomaterials

Nanoparticles (NPs) have unique physicochemical properties that are useful for a broad range of biomedical and industrial applications; nevertheless, increasing concern exists about their biosafety. This review aims to focus on the implications of nanoparticles in cellular metabolism and their outcomes. In particular, some NPs have the ability to modify glucose and lipid metabolism, and this feature is especially interesting to treat diabetes and obesity and to target cancer cells. However, the lack of specificity to reach target cells and the toxicological evaluation of nontargeted cells can potentially induce detrimental side effects, closely related to inflammation and oxidative stress. Therefore, identifying the metabolic alterations caused by NPs, independent of their application, is highly needed. To our knowledge, this increase would lead to the improvement and safer use with a reduced toxicity, increasing the number of available NPs for diagnosis and treatment of human diseases.

Osteoimmune Interactions and Therapeutic Potential of Macrophage-Derived Small Extracellular Vesicles in Bone-Related Diseases

Due to the aging of the global population, the burden of bone-related diseases has increased sharply. Macrophage, as indispensable components of both innate immune responses and adaptive immunity, plays a considerable role in maintaining bone homeostasis and promoting bone establishment. Small extracellular vesicles (sEVs) have attracted increasing attention because they participate in cell cross-talk in pathological environments and can serve as drug delivery systems. In recent years, an increasing number of studies have expanded our knowledge about the effects of macrophage-derived sEVs (M-sEVs) in bone diseases via different forms of polarization and their biological functions. In this review, we comprehensively describe on the application and mechanisms of M-sEVs in various bone diseases and drug delivery, which may provide new perspectives for treating and diagnosing human bone disorders, especially osteoporosis, arthritis, osteolysis, and bone defects.

Transcriptome Sequencing Reveals Key Genes in Three Early Phases of Osteogenic, Adipogenic, and Chondrogenic Differentiation of Bone Marrow Mesenchymal Stem Cells in Rats

Bone mesenchymal stem cells (BMSCs) of multi-directional differentiation and reproductive activity are attractive candidates for bone and cartilage repair. However, the molecular mechanisms underlying the early phase of osteogenesis, adipogenesis, and chondrogenesis of BMSCs are still far from understood. In the current study, BMSCs are isolated from rats, and the gene expressions during the initiation of differentiation (phase I), lineage acquisition (phase II), and early lineage progression (phase III) of three-directional differentiation of BMSCs were detected by using high-throughput sequencing. Then, 356, 540, and 299 differentially expressed genes (DEGs) were identified in phases I, II, and III of osteogenesis, respectively. The numbers are 507, 287, and 428 for adipogenesis, respectively, and 412, 336, and 513 for chondrogenesis, respectively. Time-dependent expression patterns of genes were also validated during three-directional differentiation in BMSCs. Hub genes including Ccna2, Cdc20, and Il6 may act as common participants in initiating osteogenesis, adipogenesis, and chondrogenesis. Mex3b, Sertad1, and Hopx showed an enhanced expression throughout three early phases during the osteogenic differentiation but no significant change in other two-directional differentiation. A similar pattern of Dtx4 and Ibsp expression occurred in adipogenesis and chondrogenesis, respectively. Our findings will help understand the underlying mechanism determining the differentiation fate of BMSCs and provide theoretical support for the clinical treatment of osteoporosis, osteoarthritis, and other age-related bone diseases.

Transcriptome Sequencing Reveals Key Genes in Three Early Phases of Osteogenic, Adipogenic, and Chondrogenic Differentiation of Bone Marrow Mesenchymal Stem Cells in Rats

Bone mesenchymal stem cells (BMSCs) of multi-directional differentiation and reproductive activity are attractive candidates for bone and cartilage repair. However, the molecular mechanisms underlying the early phase of osteogenesis, adipogenesis, and chondrogenesis of BMSCs are still far from understood. In the current study, BMSCs are isolated from rats, and the gene expressions during the initiation of differentiation (phase I), lineage acquisition (phase II), and early lineage progression (phase III) of three-directional differentiation of BMSCs were detected by using high-throughput sequencing. Then, 356, 540, and 299 differentially expressed genes (DEGs) were identified in phases I, II, and III of osteogenesis, respectively. The numbers are 507, 287, and 428 for adipogenesis, respectively, and 412, 336, and 513 for chondrogenesis, respectively. Time-dependent expression patterns of genes were also validated during three-directional differentiation in BMSCs. Hub genes including Ccna2, Cdc20, and Il6 may act as common participants in initiating osteogenesis, adipogenesis, and chondrogenesis. Mex3b, Sertad1, and Hopx showed an enhanced expression throughout three early phases during the osteogenic differentiation but no significant change in other two-directional differentiation. A similar pattern of Dtx4 and Ibsp expression occurred in adipogenesis and chondrogenesis, respectively. Our findings will help understand the underlying mechanism determining the differentiation fate of BMSCs and provide theoretical support for the clinical treatment of osteoporosis, osteoarthritis, and other age-related bone diseases.