Search Results (649)

The global prevalence of osteoporosis is rising, particularly among the elderly and post-menopausal population. Although natural flavonoids can inhibit osteoclast overactivation, their low abundance and extraction challenges limit clinical translation. In this study, we synthesized a flavonoid derivative, SZQ-4, and evaluated its therapeutic potential for post-menopausal osteoporosis (PMO). Using an RANKL-induced osteoclastogenesis model in vitro, we demonstrated through TRAP staining, RT-qPCR, and bone resorption assays that SZQ-4 significantly suppresses osteoclast formation and activity. Mechanistically, RNA-seq, Western blot, siRNA knockdown, and plasmid-based overexpression experiments revealed that SZQ-4 reduces RANKL-induced reactive oxygen species (ROS) production, regulates SIRT3 expression, and improves mitochondrial function, thereby attenuating osteoclast differentiation. In an ovariectomy-induced bone loss mouse model, SZQ-4 treatment markedly alleviated femoral bone loss, decreased osteoclast numbers, and lowered ROS levels in the bone marrow microenvironment. Collectively, our findings indicate that SZQ-4 inhibits osteoclast-driven bone resorption by modulating the ROS-SIRT3–mitochondrial function axis, highlighting its potential as a candidate for preventing pathological bone loss. Full article

Acute myeloid leukemia (AML) is an aggressive hematologic malignancy characterized by profound molecular heterogeneity and high relapse rates, posing significant clinical challenges. Programmed cell death (PCD), encompassing diverse regulated modalities such as apoptosis, necroptosis, and ferroptosis, plays a key role in leukemogenesis and therapeutic response; however, a comprehensive prognostic framework integrating multi-modal PCD pathways in AML remains elusive. In this study, we performed a systematic transcriptomic analysis of 1624 genes associated with 13 distinct PCD forms. A novel computational pipeline combining a variational autoencoder (VAE) for dimensionality reduction and a multilayer perceptron (MLP) for classification was employed to identify robust PCD-related biomarkers, interpreted via SHapley Additive exPlanations (SHAP) analysis. This approach identified 48 candidate genes with discriminative potential between AML and normal bone marrow. Unsupervised consensus clustering based on these genes delineated two molecular subtypes exhibiting divergent clinical outcomes and immune microenvironment profiles. The subtype demonstrated an immunosuppressive phenotype, characterized by enriched regulatory T cells, M2 macrophages, and elevated expression of inhibitory immune checkpoints, correlating with inferior survival. We developed an 8-gene prognostic signature (SORL1, PIK3R5, RIPK3, ELANE, GPX1, VNN1, CD74, and IL3RA) that effectively categorized patients into high- and low-risk groups with notable survival differences, validated across independent cohorts. A prognostic nomogram combining the risk score, age, and cytogenetic risk enhanced the prediction accuracy for overall survival. Our study presents an integrative model that connects multi-modal PCD pathways to AML prognosis, offering a new molecular subtyping system and a clinically applicable risk assessment tool for improved prognostication and personalized treatment strategies. Full article

Background/Objectives: FcγRIIIA presents a single nucleotide polymorphism at position 158 (V/F), which affects its binding affinity to the fragment crystallizable (Fc) of antibodies (Abs). In the presence of immune complexes, FcγRIIIA can mediate the inflammatory signaling, severity of bone disease, and osteoclastogenic activity. Based on this functional relevance, we hypothesized that the FcγRIIIA F158V polymorphism may influence the clinical presentation of multiple myeloma (MM). Methods: FcγRIIIA F158V genotyping was performed on genomic DNA extracted from peripheral blood samples of patients affected by MM or asymptomatic conditions named MGUS and SMM. We compared the allele frequency of FcγRIIIA-F158V polymorphism in 72 MM, 42 MGUS and 31 SMM and evaluated the association with clinical features and occurrence of high-risk chromosome abnormalities. Targeted NGS mutation analysis was performed on genomic DNA isolated from purified CD138⁺ bone marrow plasma cells (BMPCs) of 41 patients, to evaluate the association between somatic mutations and the FcγRIIIA F158V genotype. Results: the FcγRIIIA-158 V/V homozygous genotype was associated with high-risk cytogenetics, anemia, high beta-2 microglobulin levels, and more than 10 osteolytic lesions. V/V homozygous genotype was significantly associated with at least one mutation in RAS pathway genes (N-RAS, K-RAS or B-RAF). In the immune microenvironment, patients carrying the V/V homozygous genotype had a higher percentage of CD14⁺CD16⁺⁺ non-conventional inflammatory monocytes than the V/F or FF genotype. Conclusions: Our study contributes to a better understanding of the interactions between genetic variants, tumor microenvironment, and therapeutic response in plasma cell dyscrasias, to identify molecular biomarkers for precision medicine in MM, MGUS and SMM. Full article

Multiple myeloma (MM) is an incurable plasma cell malignancy characterized by high metabolic activity, chronic endoplasmic reticulum stress, and persistent redox imbalance. Excessive immunoglobulin synthesis and adaptation to the hypoxic bone marrow microenvironment lead to sustained production of reactive oxygen species (ROS). Their excessive accumulation promotes genomic instability, disease progression, osteolytic bone disease, and resistance to therapy. Paradoxically, MM cells adapt to oxidative stress by activating antioxidant and metabolic defense mechanisms, including Nuclear factor erythroid 2-related factor 2 (NRF2)- and Heme Oxygenase 1 (HMOX1)-dependent pathways, metabolic reprogramming, and overexpression of ROS-scavenging enzymes such as peroxiredoxin 6 (PRDX6), allowing survival at the threshold of oxidative toxicity. Evidence indicates that biomarkers of oxidative stress—such as lipid and protein oxidation products, antioxidant enzyme activity, and the Oxidative Stress Score—correlate with disease stage, prognosis, and treatment response. Redox-modulating therapeutic strategies, including pharmacological ROS induction, inhibition of antioxidant defenses, and the use of natural pro-oxidant compounds, are emerging as promising adjuncts to standard MM therapies. Recent studies also highlight the gut microbiota as an indirect regulator of oxidative balance, immune modulation, and metabolic homeostasis in MM. This review summarizes current knowledge on oxidative stress in multiple myeloma, emphasizing its role in pathogenesis, drug resistance, biomarker development, and emerging therapeutic and supportive strategies. Full article

Background: Recurrent vulvovaginal candidiasis (RVVC) is a chronic inflammatory disease primarily caused by Candida albicans (C. albicans). Its pathogenesis remains incompletely understood, and clinical management is challenged by recurrence and drug resistance. Ferroptosis, an iron-dependent form of programmed cell death driven by lipid peroxidation, has been implicated in various infectious and inflammatory diseases. However, its role in RVVC remains unclear, with a particular lack of evidence from clinical samples and animal experiments. Objective: This study aimed to investigate the association between RVVC and ferroptosis. First, we analyzed high-throughput sequencing data from human RVVC samples in the Gene Expression Omnibus (GEO) database to identify the expression profile of ferroptosis-related genes. Second, using an established murine model of chronic vulvovaginal candidiasis (CVVC), we validated changes in ferroptosis-related markers in vaginal tissues in vivo. Furthermore, an in vitro model of C. albicans-infected bone marrow-derived macrophages (BMDMs) was employed to explore the underlying mechanisms. This study provides experimental evidence for elucidating the pathogenesis of RVVC and exploring novel therapeutic strategies. Methods: The RVVC-related gene expression dataset GSE278036 was obtained from the GEO database. Differentially expressed genes (DEGs) were screened using the DESeq2 algorithm and intersected with ferroptosis-related genes from the FerrDb database to identify key targets. A protein–protein interaction (PPI) network was constructed using the STRING database and Cytoscape software, and hub genes were identified via the Betweenness centrality algorithm. Functional and pathway analyses, including gene set enrichment analysis (GSEA), Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG), and WikiPathways, were performed. Immune infiltration analysis characterized the immune microenvironment in RVVC patients. A CVVC mouse model was established in vivo, and a C. albicans-BMDMs infection model was established in vitro. The ferroptosis inhibitor ferrostatin-1 (Fer-1) was administered to investigate the pathological function and regulatory mechanisms of ferroptosis in RVVC at the molecular, cellular, and tissue levels. Results: Differential analysis identified 3132 DEGs in RVVC, which intersected with ferroptosis-related genes to yield 194 key targets. Among them, 20 hub genes were identified, including ferroptosis regulators and inflammatory factors. Functional enrichment analysis confirmed that these shared targets regulate RVVC pathology through a “ferroptosis-inflammation-immunity” multi-pathway network. Immune infiltration analysis revealed a specific immune disorder in RVVC patients characterized by “activation of the pro-inflammatory innate immune axis and suppression of the adaptive immune axis,” which was closely associated with ferroptosis-related genes. In vivo and in vitro experiments confirmed that C. albicans infection induced ferroptosis in vaginal tissues and macrophages, as manifested by lipid ROS accumulation, Fe²⁺ overload, GSH depletion, downregulation of GPX4 and SLC7A11, upregulation of ACSL4, 4-HNE, and MDA, and mitochondrial structural damage. Macrophages were identified as key target cells for ferroptosis, and their ferroptosis led to impaired antifungal function. Fer-1 treatment significantly inhibited ferroptosis, reduced vaginal histopathological damage and inflammatory cell infiltration, decreased fungal burden, downregulated abnormally elevated inflammatory factors, and restored Th1/Th2 immune balance. Furthermore, Fer-1 preserved macrophage viability and enhanced their antifungal killing capacity. Conclusions: This study provides the first evidence linking RVVC to ferroptosis through a combination of clinical data analysis and experiments, suggesting that ferroptosis is involved in its pathological process. These findings offer a new perspective for elucidating RVVC pathogenesis and developing targeted therapeutic strategies. Full article

Laceration is one of the most common meniscus injuries, which can cause knee joint dysfunction. The treatment of meniscus injuries remains one of the greatest challenges in orthopedics. In this study, a three-dimensional sponge-like Poly(lactic acid)/Poly(3-hydroxybutyrate-co-4-hydroxybutyrate) (PLA/P(3HB-co-4HB)) scaffold with oriented microtubules was fabricated using an improved gradient thermal phase separation technique. The scaffold surface was modified by adsorbing gelatin. The surface-modified scaffolds and the unmodified scaffolds were divided into two groups. All preparation parameters were adjusted to meet tissue engineering requirements. The prepared scaffolds were tested for porosity, compression modulus, hydrophilicity, and degradability. Following scaffold preparation, induced differentiated rabbit bone marrow mesenchymal stem cells (BMSCs) were seeded to evaluate scaffold cytocompatibility. Cell proliferation was observed in the two scaffold groups, and cell viability was analyzed using CCK-8 assay, scanning electron microscopy (SEM), and confocal microscopy. Histological staining was performed to comparatively study cell synthetic function. Subsequently, tissue reconstruction and regeneration were evaluated following subcutaneous implantation of gelatin/PLA/P(3HB-co-4HB) scaffolds loaded with induced differentiated BMSCs in the dorsal regions of athymic nude mice. Results demonstrated that the gelatin/PLA/P(3HB-co-4HB) scaffold exhibited good cell compatibility, providing a suitable microenvironment for cell proliferation and differentiation. Furthermore, the scaffold supported the growth of seeded induced differentiated rabbit MSCs in vivo, maintaining meniscus cell phenotyping and function. The cell-laden scaffold has the potential to generate meniscus fibrocartilage. Full article

Copper–organic compounds are being investigated as antitumor candidates. Besides their efficacy as cytotoxic agents alone, the oxidative potential of electrochemical Cu²⁺-to-Cu¹⁺ transition emerges as an attractive approach for elimination of tumor cells otherwise resistant to chemotherapy. To minimize side effects of the potent oxidative burst upon Cu(II) reduction, the metal cations should be delivered to the tumor site. Taking advantage of the ability of bisphosphonates to accumulate in the bone, we synthesized a Cu(II) complex of zoledronic acid (ZA), an FDA-approved drug for prevention of bone destruction. The CuZA complex obtained upon precipitation of ZA and different copper salts (sulfate, chloride or perchlorate) were structurally identical, consisting of two organic moieties coordinated by three metal cations. Combined treatment with water-soluble formulations of CuZA and cysteine triggered rapid death in human cell lines. This effect was achievable with non-toxic concentrations of CuZA and cysteine alone. Importantly, the K562 chronic myelogenous leukemia cells that demonstrated an attenuated response to the 3d generation Bcr-Abl tyrosine kinase inhibitor in the medium conditioned by bone marrow-derived fibroblasts, were readily killed by CuZA–cysteine combination. Thus, oxidative burst upon metal reduction in CuZA complexes emerges as a promising method of eradication of tumor cells in the bone microenvironment. Full article

Bone is a dynamic and multifunctional tissue that provides mechanical support, regulates mineral homeostasis, supports hematopoiesis, and relies on complex interactions among multiple cell types. The increasing incidence of bone-related diseases, such as osteoporosis, osteoarthritis, fracture non-union, and bone cancer, highlights the need for in vitro models that better reflect human bone physiology. Bone-on-a-chip technology, developed through advances in microfluidics, biomaterials, and tissue engineering, offers a promising approach to recreate key features of the bone microenvironment in vitro. By incorporating bone-mimicking materials, relevant bone cells, vascular components, fluid perfusion, and mechanical stimulation, these platforms allow more realistic investigation of bone remodeling, regeneration, disease mechanisms, and drug responses. In parallel, bone organoids and their integration with microfluidic chips have further expanded the capabilities of in vitro bone models by enabling the formation of self-organized, human-relevant bone tissues with increased cellular complexity. This review summarizes recent progress in bone-on-a-chip systems, including models for osteogenesis and bone regeneration, vascularized bone, bone marrow and hematopoietic niches, cancer bone metastasis, and mechanobiological studies. Key design principles, materials, cellular components, and applications in disease modeling, drug screening, toxicity assessment, and personalized medicine are discussed. Current challenges and future directions are also discussed to support the continued development of more physiologically relevant in vitro bone models. Full article

Cartilage is an important yet vulnerable tissue with limited self-healing capacity, where damage often progresses to joint degeneration, which eventually leads to severe osteoarthritis (OA). Current tissue engineering strategies focus on biocompatible scaffolds for cartilage regeneration, particularly amnion (or amniotic membrane), emerging as a promising biomaterial due to its wide availability, low immunogenicity, and naturally derived microenvironment that is advantageous for cartilage regeneration. This systematic review aims to evaluate the existing evidence on the efficacy of amnion as a tissue scaffolding material for cartilage regeneration in both preclinical and clinical studies. Using terms such as “cartilage damage”, “cartilage injuries”, “amnion” and “amniotic membrane”, 19 relevant studies were identified across three major databases (PubMed, Scopus and Web of Science) until 25 December 2025. All preclinical and clinical studies that utilized amnion for cartilage repair or as cartilage tissue engineering scaffolding materials were included. Evidence quality was assessed using the OHAT and MINORS risk of bias tool. This study is prospectively registered in the PROSPERO database under the ID 1178444. The findings consistently indicate that amniotic scaffolds, regardless of processing methods or cell seeding, yield favorable outcomes without adverse effects across different species. In vitro analysis revealed that treatment groups with amnion show better cell attachment, viability, and proliferation, and higher content of cartilage-related markers expressed by the seeded cells, either chondrocyte, bone marrow-derived mesenchymal stem cells (MSCs), adipose tissue-derived MSCs, placenta-derived MSCs, umbilical cord-derived MSCs, amniotic MSCs or amniotic epithelial cells. In in vivo and ex vivo studies, amnion-treated groups demonstrated improved quality of the treated cartilage, with better integration, as indicated by higher histological scores and the presence of type II collagen (COL-II). There was an inconsistency in the reporting of cartilage defect dimensions in the in vivo models across the different studies. Nevertheless, the outcome measurements were consistently reported with histological analysis, with or without International Cartilage Repair Society (ICRS) scoring and immunohistochemistry (IHC) analysis, across the studies. Clinically, most subjects show improvement in the Knee Injury and Osteoarthritis Outcome Score (KOOS) Sports and Recreation score and KOOS Quality of Life score, as well as reduced Visual Analogue Scale (VAS) average and maximum pain scores. In conclusion, preclinical and clinical studies support amnion as an ideal scaffold material for cartilage tissue engineering and regeneration. Future research should focus on optimizing and standardizing amnion scaffold preparation at a production scale to facilitate the translation of these positive outcomes into clinical applications. This study is funded by the Ministry of Higher Education Malaysia via Prototype Research Grant Scheme (PRGS/1/2021/SKK01/UM/02/1) and UM International Collaboration Grant—2023 SATU Joint Research Scheme Program: ST007-2024. Full article

Mesenchymal stem cells (MSCs) sense biophysical cues from their microenvironment, which regulate cytoskeletal organization and the nuclear–cytoplasmic distribution of the mechanotransducer Yes-associated protein (YAP), thereby shaping cellular behavior. Prolonged ex vivo culture on non-physiologically rigid substrates induces persistent nuclear YAP localization, a phenomenon often referred to as mechanical memory. We therefore examined whether transient epigenetic modulation could modulate YAP subcellular localization in human bone marrow-derived MSCs. Treatment with the DNA methyltransferase inhibitor 5-azacitidine (5-Aza) shifted YAP localization toward the cytoplasm in MSCs, without overt changes in pluripotency marker expression or neural differentiation capacity. RNA sequencing revealed broad down-regulation of extracellular matrix (ECM)-related genes following 5-Aza treatment. Independent suppression of ECM production via TGF-β signaling similarly promoted cytoplasmic YAP localization. When subsequently transferred to soft substrates, 5-Aza–treated MSCs restored YAP relocalization despite prior expansion on stiff surfaces. Together, these findings suggest that transient 5-Aza treatment can partially alleviate mechanically induced YAP regulation associated with mechanical memory. Thus, simple and transient administration of 5-Aza may offer a practical means to improve the quality of MSCs during ex vivo expansion for cell-based therapies. Full article

Hepatocellular carcinoma (HCC) remains a leading cause of cancer-related death, yet adequate in vitro models mimicking the tumor immune microenvironment (TIME) are rare. Specifically, the role of the transcription factor nuclear factor erythroid 2-related factor 2 (Nrf2) in modulating interactions between tumor cells and tumor-associated macrophages (TAMs) is not fully understood. We established a 3D multicellular tumor spheroid (MCT) model using murine N-HCC25 cells with CRISPR/Cas9-mediated knockouts of Nrf2 and its negative regulator Kelch-like ECH-associated protein 1 (Keap1), the latter mimicking constitutive activation. N-HCC25 cells were co-cultured with bone marrow-derived macrophages (BMDMs) isolated from wild-type and Nrf2-knockout C57BL/6J mice. We compared co-culture setups (conditioned media, transwell systems, direct contact) using RT-qPCR, flow cytometry, and invasion assays. 3D spheroid systems better preserved stemness than 2D cultures and revealed functional Nrf2-dependent effects such as increased Vegf-α secretion in Keap1-deficient spheroids. Among the different co-cultivation models, the most profound effects were observed in the MCT model. Macrophages successfully integrated into the spheroids and triggered invasive outgrowth, whereas MCTs containing Nrf2-deficient macrophages displayed markedly reduced tumor spheroid growth and lower programmed cell death ligand-1 expression. These findings demonstrate that Nrf2 signaling in macrophages fosters an immunosuppressive and pro-invasive microenvironment. The established MCT model provides a suitable platform to further unravel Nrf2-dependent mechanisms in the HCC TIME. Full article

The development of targeted treatments, including inhibitors of BCL-2, FLT3, IDH1/2, and menin, has significantly expanded the therapeutic landscape of acute myeloid leukemia (AML), offering more personalized and molecularly driven treatment approaches. Despite these advances, achieving durable responses represents a major challenge, limited by the emergence of intrinsic and acquired resistance to targeted agents. This review summarizes the current understanding of the cellular and molecular mechanisms underlying resistance to targeted therapies in AML. Key mechanisms include acquired mutations that alter the drug target, other co-occurring genetic and epigenetic alterations, activation of bypass signaling pathways, and metabolic reprogramming. Furthermore, the role of clonal heterogeneity and the bone marrow microenvironment in the development of resistance is increasingly recognized. In addition, we discuss emerging strategies aiming at overcoming resistance, such as combination treatments and novel inhibitors designed to target resistant clones. Finally, this review highlights the critical need for mechanism-driven therapeutic design in order to achieve sustained responses and improve long-term outcomes in patients with AML. Full article

Bone metastasis is a devastating complication of advanced osteotropic malignancies, notably breast, prostate, lung carcinomas, and malignant melanoma, and remains a primary driver of mortality. Historical paradigms have conceptualized skeletal dissemination almost exclusively as a hematogenous process wherein circulating tumor cells colonize receptive bone marrow niches. However, this model fails to reconcile why lymph node metastasis consistently serves as a potent predictor of bone involvement even though therapeutic lymphadenectomy rarely prevents distant spread. This discordance suggests that lymph nodes function not merely as passive reservoirs but as active ‘evolutionary gateways’ that sculpt bone-tropic metastatic clones. In this review, we introduce the Lymphatic–Bone Axis, a framework integrating lymphatic biology into models of bone metastasis. We synthesize emerging evidence elucidating how the lymph node microenvironment primes tumor cells through CCR7-CXCR4 switching, induction of osteomimicry programs, and metabolic reprogramming that favors survival within the bone marrow. We also discuss preclinical data demonstrating direct intranodal intravasation via high endothelial venules (HEVs), providing a rapid route into the systemic circulation that bypasses the thoracic duct. Beyond consolidating current knowledge, we outline a research agenda for dissecting this axis, including longitudinal single-cell transcriptomic mapping and functional assessments of lymph node-derived tumor cells. Finally, we consider translational implications, highlighting why bone-targeted agents alone may prove insufficient once cells are conditioned within lymphatic niches. By mechanistically linking lymphatic priming to skeletal colonization, this review informs the rational design of multimodal therapeutic approaches that jointly target lymphatic transit and the bone microenvironment. Full article

In inflammatory states, eosinophils are exposed to stimuli leading to activation, increased survival, and/or different cell death subroutines, which have differing effects on tissue inflammation. The mechanisms of signal integration are poorly understood. In this manuscript, we investigated cell death types in response to stimuli mimicking the inflammatory microenvironment. Mouse bone marrow-derived eosinophils (BMDeos) were stimulated with cytokines, cell-cell interaction mimics, pathogen-associated molecular patterns (PAMP), and broad cell activation stimuli. Both PMA and crosslinking of CD95 (cCD95) induced cell death of BMDeos. However, cCD95-induced cell death was consistent with apoptosis, while activation with PMA lead to EETosis. Both stimuli lead to caspase 3 activation and increased total level of histone H3 citrullination, indicating that these outcomes are not able to discriminate between the two cell death types. Flow cytometry for annexinV/7AAD pattern at early time points, and morphologic assessment by immunofluorescence (for DNA, eosinophil granule protein and citH3) were the most reliable outcomes for distinguishing the cell death subtypes. While LPS alone did not decrease BMDeos viability, LPS in the presence of caspase inhibition (zVAD) caused delayed cell death, which did not conform to either of the two cell death types. Finally, LPS and LPS/zVAD led to an increased level of surface expression of CD274 (type 1 activation), while both cCD95 and PMA increased the surface expression of CD101 (type 2 activation). In summary, at least three different activation-associated cell death pathways are seen in BMDeos activated with microenvironment-mimicking stimuli. Crosslinking CD95 leads to type 2 activation and apoptotic cell death. PMA also leads to type 2 activation but EETosis-associated cell death. LPS and LPS/zVAD are associated with type 1 activation, and only LPS/zVAD lead to cell death via a subtype different from both apoptosis and EETosis. Full article

B cell maturation antigen (BCMA)-targeted chimeric antigen receptor T cell (CAR-T) therapy has transformed the treatment landscape for relapsed or refractory multiple myeloma (MM), with products such as idecabtagene vicleucel and ciltacabtagene autoleucel achieving high initial response rates, and in selected patient populations, durable treatment-free remission. However, a substantial proportion of patients still experience relapse, including antigen-positive progression, highlighting persistent limitations in long-term disease control across diverse clinical settings. An increasing body of evidence indicates that resistance to CAR-T therapy in MM is driven not only by tumor-intrinsic factors, but also by extrinsic pressures imposed by the bone marrow microenvironment (BMME). This review integrates current understanding of tumor-niche interactions that impair CAR-T persistence, trafficking, and effector function, including immunosuppressive cellular networks, inhibitory cytokine signaling, metabolic constraints, stromal adhesion, antigen modulation, and marrow remodeling. This review further examines emerging therapeutic strategies and next-generation CAR-T platforms. Full article