Search Results (702)

Background: Mesenchymal stem cells (MSCs) are a promising tool in regenerative medicine due to their ability to secrete paracrine factors that modulate tissue repair. Extracellular vesicles (EVs) released by MSCs contain bioactive molecules (e.g., mRNAs, miRNAs, proteins) and play a key role in intercellular communication. Methods: This study compared the transcriptomic profiles (mRNA and miRNA) of equine MSCs derived from adipose tissue (AT-MSCs), bone marrow (BM-MSCs), and ovarian fibroblasts (as a differentiated control). Additionally, miRNAs present in EVs secreted by these cells were characterized using next-generation sequencing. Results: All cell types met ISCT criteria for MSCs, including CD90 expression, lack of MHC II, trilineage differentiation, and adherence. EVs were isolated using ultracentrifugation and validated with nanoparticle tracking analysis and flow cytometry (CD63, CD81). Differential expression analysis revealed distinct mRNA and miRNA profiles across cell types and their secreted EVs, correlating with tissue origin. BM-MSCs showed unique regulation of genes linked to early development and osteogenesis. EVs contained diverse RNA species, including miRNA, mRNA, lncRNA, rRNA, and others. In total, 227 and 256 mature miRNAs were detected in BM-MSCs and AT-MSCs, respectively, including two novel miRNAs per MSC type. Fibroblasts expressed 209 mature miRNAs, including one novel miRNA also found in MSCs. Compared to fibroblasts, 60 and 92 differentially expressed miRNAs were identified in AT-MSCs and BM-MSCs, respectively. Conclusions: The results indicate that MSC tissue origin influences both transcriptomic profiles and EV miRNA content, which may help to interpret their therapeutic potential. Identifying key mRNAs and miRNAs could aid in future optimizing of MSC-based therapies in horses. Full article

Background/Objectives: Myelofibrosis (MF) is a myeloproliferative neoplasm characterized by the replacement of healthy bone marrow (BM) with malignant and fibrotic tissue. In a healthy state, bone marrow is composed of approximately 60–70% fat cells, which are replaced as disease progresses. Proton density fat fraction (PDFF), a non-invasive and quantitative MRI metric, enables analysis of BM architecture by measuring the percentage of fat versus cells in the environment. Our objective is to investigate variance in quantitative PDFF-MRI values over time as a marker of disease progression and response to treatment. Methods: We analyzed existing data from three cohorts of mice: two groups with MF that failed to respond to therapy with approved drugs for MF (ruxolitinib, fedratinib), investigational compounds (navitoclax, balixafortide), or vehicle and monitored over time by MRI; the third group consisted of healthy controls imaged at a single time point. Using in-house MATLAB programs, we performed a voxel-wise analysis of PDFF values in lower extremity bone marrow, specifically comparing the variance of each voxel within and among mice. Results: Our findings revealed a significant difference in PDFF values between healthy and diseased BM. With progressive disease non-responsive to therapy, the expansion of hematopoietic cells in BM nearly completely replaced normal fat, as determined by a markedly reduced PDFF and notable reduction in the variance in PDFF values in bone marrow over time. Conclusions: This study validated our hypothesis that the variance in PDFF in BM decreases with disease progression, indicating pathologic expansion of hematopoietic cells. We can conclude that disease progression can be tracked by a decrease in PDFF values. Analyzing variance in PDFF may improve the assessment of disease progression in pre-clinical models and ultimately patients with MF. Full article

Introduction: Despite the approval of novel agents that have significantly improved long-term survival rates for multiple myeloma (MM) patients undergoing autologous stem cell transplant (ASCT), most patients eventually relapse. The failure to achieve or maintain bone marrow (BM) minimal residual disease (MRD) negativity is a recognised adverse prognostic factor for progression-free survival (PFS) and overall survival (OS). Contamination of stem cell apheresis by clonal plasma cells may also affect prognosis, though data remain limited. Methods: We conducted a prospective, single-centre observational study including 100 newly diagnosed MM patients eligible for ASCT and treated with bortezomib-based triplet induction. MRD was assessed both on BM and apheresis samples using multiparameter flow cytometry (MFC-MRD) with a sensitivity of 10⁻⁵. Results: Clonal plasma cells were detected in 22 apheresis samples (aMRD+), all of which were associated with BM MRD positivity. Patients with aMRD+ had inferior pre-ASCT responses (≥VGPR: 10% vs. 63%, p = 0.005) and worse post-ASCT BM MRD negativity rates (4% vs. 49%, p = 0.048). After a median follow-up of 52.4 months, aMRD+ was associated with shorter progression-free survival (median 38.5 vs. not reached, p = 0.007) and overall survival (median 60 months vs. not reached, p = 0.003). Conclusions: Contamination of the apheresis product is associated with persistent BM disease and poorer outcomes. Combined MRD assessment in both bone marrow and apheresis may improve risk stratification in MM patients undergoing ASCT. Full article

Human cytomegalovirus (HCMV) establishes lifelong latency in the host, with the bone marrow (BM) CD34+ cells serving as a key reservoir. To investigate tissue-specific immune responses to CMV, we analysed paired peripheral blood mononuclear cells (PBMCs) and bone marrow mononuclear cells (BMMNCs) from HCMV-seropositive donors using multiparametric flow cytometry and cytokine FluroSpot assays. We assessed immune cell composition, memory T cell subsets, cytokine production, cytotoxic potential, activation marker expression, and checkpoint inhibitory receptor (CIR) profiles, both ex vivo and following stimulation with lytic and latent HCMV antigens. BMMNCs were enriched in CD34+ progenitor cells and exhibited distinct T cell memory subset distributions. HCMV-specific responses were compartmentalised: IFN-γ responses predominated in PBMCs following lytic antigen stimulation, while IL-10 and TNF-α responses were more prominent in BMMNCs, particularly in response to latent antigens. US28-specific T cells in the BM showed elevated expression of CD39, PD-1, BTLA, CTLA-4, ICOS, and LAG-3 on CD4+ T cells and increased expression of PD-1, CD39, BTLA, TIGIT, LAG-3, and ICOS on CD8+ T cell populations, suggesting a more immunoregulatory phenotype. These findings highlight functional and phenotypic differences in HCMV-specific T cell responses between blood and bone marrow, underscoring the role of the BM niche in shaping antiviral immunity and maintaining viral latency. Full article

Background: Bone marrow mesenchymal stem cells (BM-MSCs) are significant in chemo- and radiotherapy resistance. Previous research has focused on BM-MSCs, demonstrating their functional involvement in cancer progression as mediators in the tumor microenvironment. They play multiple roles in tumorigenesis, angiogenesis, and metastasis. BM-MSC-derived exosomes (BM-MSCs-exo) are small vesicles, typically 50–300 nm in diameter, isolated from BM-MSCs. Some studies have demonstrated the tumor-suppressive effects of BM-MSCs-exo. Objective: This study aimed to investigate their role in modulating the impact of chemoradiotherapy (CRT) in different types of cervical cancer spheroid cells. Methods: The spheroids after treatment were subject to size measurement, cell viability, and caspase activity. Then, the molecular mechanism was elucidated by Western blot analysis. Results: We observed a reduction in spheroid size and an increase in cell death in HeLa spheroids, while no significant changes in size or cell viability were found in SiHa spheroids. At the molecular level, CRT treatment combined with BM-MSCs-exo in HeLa spheroids induced apoptosis through the activation of the NF-κB pathway, specifically via the NF-κB1 (P50) transcription factor, leading to the upregulation of apoptosis-related molecules. In contrast, CRT combined with BM-MSCs-exo in SiHa spheroids exhibited an opposing effect: although cellular viability decreased, caspase activity also decreased, which correlated with increased HSP27 expression and the subsequent downregulation of apoptotic molecules. Conclusion: Our study provides deeper insight into the potential of BM-MSCs-exo in cervical cancer treatment, supporting the development of more effective and safer therapeutic strategies for clinical application. Full article

Megakaryocytes (MKs), which primarily develop in bone marrow (BM) from hematopoietic stem cells, are critical for platelet production. Beyond their well-established role in thrombopoiesis, MKs have been identified as important for BM niche maintenance, such as by supporting the growth and differentiation of other cell types. Recently, megakaryopoiesis has been reported as yielding divergent subpopulations of MKs, as evidenced by single-cell RNA sequencing of lung, spleen, or BM resident MKs. Interestingly, these subpopulations constitute a significant proportion of “immune MKs” expressing various classical immune markers and capable of phagocytosing pathogens and contributing to antigen presentation. As such, MKs were also found to regulate inflammation, mainly by secreting various cytokines and chemokines to crosstalk with other cell types. The level and functional signature of these “immune MKs” were found to be altered in various pathological conditions, indicative of their purposeful values in health and diseases. In this review, we survey and highlight newly reported functional immune and inflammatory properties of MKs in health and in select pathologies. Full article

Background/objectives: Despite advancements in early diagnosis and clinical practices guided by standardized care protocols, Merkel cell carcinoma (MCC) is marked by an unfavorable prognosis with a 5-year relative survival rate of 65%, based primarily on data collected prior to the introduction of immunotherapy. Regional nodal metastases affect 40–50% of MCC patients, while approximately 33% experience distant dissemination. Among these, bone and bone marrow metastases are particularly notable, although the characteristics and clinical implications of this metastatic disease in MCC remain poorly understood. Methods: A comprehensive review was conducted using the Medline database (via PubMed) up to January 2025. The search strategy included the string “(Merkel cell carcinoma AND (bone OR marrow))”. Results: A total of 1133 (69.3% male and 30.7% female) patients diagnosed with advanced MCC were collected. The median (IQR) age at diagnosis was 67.5 (12.65) years old. Overall, 201 (20.8%) cases of bone and/or bone marrow metastases were identified and linked to a primary known MCC in 75.7% of cases. Bone metastases (BMs) appear as the third most common metastatic site, following the liver (second) and lymph nodes (first). They show mixed biological and radiological behavior, with a marked preference for the axial skeleton over the appendicular one. Addressing the characteristics of metastatic bone disease, neurological symptoms were the most documented, whereas bone marrow involvement and leukemic spread seemed to be primarily related to immunosuppression. Multimodal treatment strategies, including platinum-based chemotherapy and radiotherapy, were the primary approaches adopted, reflecting therapeutic practices from the pre-immunotherapy era. Conclusions: The pattern of metastatic spread in MCC differs among studies, with the bones resulting as the third most common site of distant spread. Excluding head and neck MCC, which seems to be more regularly associated with liver metastases, the relationship between the primary tumor site and the development of bone or bone marrow metastases appears inconsistent. Overall, BMs mostly correlated with advanced MCC stages and poorer survival outcomes, with a median overall survival (OS) of 8 months (range 12.75–4). The integration of international guidelines, evolving evidence from clinical trials, and the expanding role of immune checkpoint inhibitors (ICIs) will contribute to improving systemic disease control and enhance patient care. Full article

Mesenchymal stem cells (MSCs) represent a promising cell source for cartilage tissue engineering due to their chondrogenic potential. However, current differentiation protocols result in limited efficiency. This study assessed the combined effects of transforming growth factor-beta 3 (TGF-β3) and fibroblast growth factor-2 (FGF-2) on the morphology, proliferation, chondrogenic differentiation, chondrogenic gene expression, and cytokine profile of ovine bone marrow-derived MSCs (BM-MSCs). BM-MSCs were cultured under four conditions: control (αMEM) or αMEM supplemented with FGF-2, TGF-β3, or TGF-β3 + FGF-2. Morphological and proliferation analyses, Alcian blue staining in 2D and 3D, and real-time PCR for early (Chad, Comp, and Sox 5) and late (Agg, Col IX, Sox 9, and Fmod) chondrogenic markers were performed. Cytokine secretion profiles were analyzed using multiplex assay. TGF-β3 induced morphological changes indicative of early chondrogenesis, while FGF-2 enhanced proliferation. The combination of both cytokines led to a synergistic increase in cell proliferation, early and late chondrogenic gene expression, and glycosaminoglycans (GAG) deposition. Cytokine analysis revealed that TGF-β3 enhanced the immunomodulatory and angiogenic profile of BM-MSCs, whereas co-treatment with FGF-2 yielded a balanced and potentially regenerative secretome. Dual stimulation with TGF-β3 and FGF-2 significantly improves the chondrogenic differentiation of ovine BM-MSCs by enhancing both molecular and functional markers of cartilage formation. Full article

Mesenchymal stem cells (MSCs) have recently shown great promise as potential anticancer drug delivery carriers. MSCs exhibit tropism to inflammatory sites, such as tumor beds, and resistance to chemotherapeutics. The aim of this study was to examine the efficacy of gemcitabine (GEM) conjugated with flurbiprofen (FLU) as a potential agent enhancing the GEM cytotoxic effect. Pancreatic cancer cell lines (PCCs), including PANC-1, AsPC-1, and BxPC-3, were studied meticulously. Moreover, the usefulness of bone-marrow-derived mesenchymal stem cells (BM-MSCs) treated with GEM and FLU, and the conditioned media from above these cells (CM) as elements supporting the in vitro action of GEM, inducing apoptosis, necrosis, and inhibiting the cell cycle, was tested. The results showed that CM-GEM exhibited higher cytotoxicity towards the selected PCCs compared to GEM alone. Furthermore, the obtained data revealed lower sensitivity of these cells to treatment, which promotes the utilization of BM-MSCs as potential drug carriers. Based on the presented findings, it seems that applying FLU in the antiproliferative effect of GEM might be regarded as an effective strategy in the therapy of pancreatic cancer, especially in the inhibition of proliferation and induction of cancer cell death. Full article

In children without Down syndrome who have acute megakaryoblastic leukemia (AMKL), inv(16)(p13q24)/CBFA2T3::GLIS2 is the most frequent genetic aberration. Pediatric CBFA2T3::GLIS2-positive AMKL is strongly associated with a poor prognosis and a high cumulative incidence of relapse. One of the key laboratory signs of CBFA2T3::GLIS2-positive AMKL is the RAM immunophenotype, which looks very similar to that of solid-tumor bone marrow (BM) infiltration. For this reason, in cases of isolated extramedullary involvement of CBFA2T3::GLIS2-positive AMKL, excluding solid tumors may be challenging. We report a case of a girl with isolated extramedullary CBFA2T3::GLIS2-positive AMKL relapse, which was misdiagnosed as secondary Ewing sarcoma. The morphological differential diagnosis between Ewing sarcoma and AMKL presented significant challenges owing to their overlapping histological features (small, round blue-cell morphology and similar growth patterns). The tumor cells’ immunophenotype completely mirrored that at the initial diagnosis of AMKL. Additional cytogenetic and molecular studies confirmed the presence of the CBFA2T3::GLIS2 fusion, but no Ewing sarcoma-specific EWSR1, FUS and CIC fusion transcripts were found. Thus, extramedullary CBFA2T3::GLIS2-positive AMKL relapse was confirmed. The presented case demonstrates the difficulties in differential diagnosis between AMKL relapse and the development of a secondary tumor. Full article

Reciprocal signaling between acute myeloid leukemia (AML) cells and the surrounding bone-marrow microenvironment (BMME) promotes AML progression through several mechanisms. One of the most important mechanisms is the induction of Galectin-3 (Gal-3) expression by AML cells and bone marrow mesenchymal stromal cells (BM-MSCs). Emerging evidence indicates that Gal-3 upregulation in the BMME promotes AML cell adhesion and survival, leading to the development of chemotherapy resistance, relapse, and poor prognosis. Identifying the biological function and critical signaling pathways of Gal-3 may contribute to overcoming acquired drug resistance and preventing post-treatment relapse. Gal-3 is involved in several molecular signaling pathways, including PI3K/AKT/mTOR, Ras/Raf/MEK/ERK, JAK/STAT, JNK, Wnt/β-catenin, PLC/PKC and NF-κB, which are interconnected to promote AML cell survival and resistance to chemotherapy. This review focuses on the biological effects, molecular mechanisms of action and regulation of Gal-3 in the pathogenesis and progression of AML. The therapeutic potential of potent synthetic small-molecule Gal-3 inhibitors in high-risk patients with AML is also discussed based on preclinical and clinical evidence from several human diseases. Currently, the effect of these Gal-3 inhibitors in AML has not been investigated either in vitro or in vivo. The findings provide a rationale for targeting Gal-3 that may be a very promising therapeutic approach, especially for patients with relapsed/refractory AML, and may enhance the efficacy of conventional chemotherapeutic drugs and/or immune checkpoint inhibitors. Full article

Nanotechnology is transforming contemporary medicine by providing cutting-edge tools for the treatment and diagnosis of complex disorders. Advanced techniques such as bioimaging and photodynamic therapy (PDT) combine early diagnosis and targeted therapy, offering a more precise approach than conventional treatments. However, a significant obstacle for PDT is the need to selectively deliver photosensitizers to disease sites while minimizing systemic side effects. In this context, mesenchymal stem cells have emerged as promising biological carriers due to their natural tropism towards tumors, low immunogenicity, and their ability to overcome biological barriers. In this study, two push–pull compounds, NPI-PTZ and BTZ-PTZ, phenothiazine derivatives featuring aggregation-induced emission (AIE) abilities, were analyzed. These molecules proved to be excellent fluorescent probes and photosensitizing agents. When administered to human bone marrow-derived multipotent stromal cells (hBM-MSCs) and human adipose multipotent stem cells (hASCs), the compounds were efficiently internalized, maintained a stable fluorescent emission for several days, and showed phototoxicity after irradiation, without inducing major cytotoxic effects under normal conditions. These results highlight the potential of NPI-PTZ and BTZ-PTZ combined with mesenchymal stem cells as theranostic tools, bridging bioimaging and PDT, and suggest new possibilities for advanced therapeutic approaches in clinical applications. Full article

Background: Chronic ischemic stroke presents a significant challenge in neurology, with limited therapeutic options available for long-term recovery. During cerebral infarction, anti-inflammatory phenotype microglia/macrophages produce anti-inflammatory cytokines and neurotrophic factors that facilitate the process of brain repair. However, obtaining sufficient anti-inflammatory microglia/macrophages from the human central nervous system is challenging. Bone marrow-derived inducible microglia-like cells (BM-iMGs) with an anti-inflammatory microglial phenotype were explored to induce neuroprotective properties. Here, we transplanted BM-iMGs into the brain of middle cerebral artery occlusion (MCAO) model male mice to explore their potential for treating chronic ischemic stroke. Methods: Bone marrow-derived mononuclear cells (BM-MNCs) were isolated from green fluorescent protein mice and incubated with granulocyte–macrophage colony-stimulating factor (GM-CSF) and IL-4 to induce BM-iMGs with an anti-inflammatory phenotype. BM-iMGs were transplanted into the brains of mice on day 14 after MCAO, and behavioral tests, histology, cerebral blood flow, and gene expression were evaluated. Results: An intracranial injection of BM-iMGs promoted neurobehavioral recovery, reduced neuronal cell loss, suppressed neuroinflammatory astrocytic and microglial responses in the brain, and increased cortical surface cerebral blood flow in MCAO mice. Furthermore, neuroprotective genes were upregulated, whereas proinflammatory genes were downregulated. Conclusions: The intracranial injection of BM-iMG cells shows significant potential as a novel therapy for chronic ischemic stroke. Full article

Aging disrupts the bone marrow (BM) niche, a complex microenvironment crucial for hematopoietic stem cell (HSC) maintenance. A key, yet debated, hallmark of this aging process is the accumulation of bone marrow adipocytes (BMAds). This review explores the evolving role of BMAds in the aging BM, particularly their influence on HSC regulation via metabolic, endocrine, and inflammatory pathways. Aging BMAds exhibit altered secretory profiles, including reduced leptin and adiponectin and increased pro-inflammatory signals, which skew hematopoiesis toward myeloid over lymphoid lineage production. Additionally, shifts in fatty acid composition and lactate signaling from BMAds may impair stem cell function. These changes, alongside aging-associated alterations in vascular, neural, and stromal components of the niche, contribute to diminished immune resilience in older adults. We discuss emerging therapeutic strategies targeting BMAd-derived factors, such as DPP4 inhibition or the modulation of β-adrenergic signaling, aimed at creating a more youthful BM environment. By summarizing current insights into the aging BM niche and the central role of BMAds, this review highlights mechanisms that could be targeted to rejuvenate hematopoiesis and improve immune function in the elderly. Full article

Biomaterials play a crucial role in the long-term success of bone implant treatment. The accumulation of bacterial biofilm on the implants induces inflammation, leading to implant failure. Modification of the implant surface with bioactive molecules is one of the strategies to improve biomaterial compatibility and limit inflammation. In this study, whey protein isolate (WPI) fibrillar coatings were used as a matrix to incorporate biologically active phenolic compound phloroglucinol (PG) at different concentrations (0.1% and 0.5%) on titanium alloy (Ti6Al4V) scaffolds. Successful Ti6Al4V coatings were validated by X-ray photoelectron spectroscopy (XPS), showing a decrease in %Ti and increases in %C, %N, and %O, which demonstrate the presence of the protein layer. The biological activity of PG-enriched WPI (WPI/PG) coatings was assessed using bone-forming cells, human bone marrow-derived mesenchymal stem cells (BM-MSCs). WPI/PG coatings modulated the behavior of BM-MSCs but did not have a negative impact on cell viability. A WPI with higher concentrations of PG increased gene expression relative to osteogenesis and reduced the pro-inflammatory response of BM-MSCs after biofilm stimulation. Autoclaving reduced WPI/PG bioactivity compared to filtration. By using WPI/PG coatings, this study addresses the challenge of improving osteogenic potential while limiting biofilm-induced inflammation at the Ti6Al4V surface. These coatings represent a promising strategy to enhance implant bioactivity. Full article