Search Results (761)

There is evidence that mast cells contribute to skeletal response to injury, but it is less clear whether these immune cells directly influence normal bone growth and turnover. Mature mast cells are common in the bone marrow of humans and rats, but have not been convincingly demonstrated to be present in the bone marrow of healthy mice, potentially limiting the mouse as a model for characterizing the full range of mast cell/bone cell interactions. An initial goal of this investigation was to comprehensively screen seven strains of mice for mature mast cells in bone marrow. Finding none, we then investigated three approaches to home these cells to the marrow of mice unable to generate mast cells: (1) administration of soluble kit ligand to membrane kit ligand-deficient Kit^Sl/Sld mice, (2) adoptive transfer of wild-type hematopoietic stem cells to kit receptor-deficient Kit^W/W−v mice, and (3) adoptive transfer of wild-type mouse bone marrow-derived mast cells generated in vitro and delivered intravenously to Kit^W/W-v mice. Only the third approach was successful. Using this method, we then evaluated the impact of bone marrow-derived mast cells on bone mass, architecture, turnover, and gene expression. The adoptive transfer of mast cells resulted in alterations in cancellous bone microarchitecture and cell populations in the vertebra, and in differential expression of genes associated with bone metabolism in the tibia. Taken together, our results support the concept that bone marrow mast cells influence bone metabolism and suggest that homing mast cells to the bone marrow of mice is a useful model to understand the role of these cells in skeletal health and disease. Full article

Objectives: To investigate the characteristics of monoclonal human urine-derived stem cells (hUSCs) obtained through different culture protocols and compare their therapeutic effects on renal ischemia–reperfusion injury in mice. Methods: Monoclones of hUSCs derived from the urine of healthy volunteers were isolated and cultured using two different culture media. Flow cytometry, qRT-PCR and RNA sequencing were employed to characterize each monoclonal clone of multipotent stem cells across multiple passages. To evaluate their therapeutic effects on unilateral renal ischemia–reperfusion injury in BALB/c mice, 5 × 10⁵ hUSCs from each monoclonal clone were intravenously administered to mice via the tail vein, followed by assessments using Masson staining, qRT-PCR and renal tissue transcriptomics analysis. Results: Four monoclonal strains were successfully isolated from four fresh urine samples of a healthy young male volunteer: three cultured in EGM-MV medium and one in our modified medium. All four strains demonstrated stable expression of mesenchymal stem cell-related markers over eight passages of expansion. Bioinformatics analysis of multiple cell transcriptome datasets revealed that these four cell strains are more closely related to kidney tissue than to bone marrow mesenchymal stem cells (BMSCs), adipose-derived mesenchymal stem cells (ADMSCs), induced pluripotent stem cells (iPSCs), embryonic stem cells (ESCs), and urothelial cells. Additionally, significant differences were observed in the expression of genes associated with kidney development among the four monoclonal strains. Furthermore, the therapeutic effects of different monoclonal clones on renal ischemia–reperfusion injury in mice showed notable variability. Conclusions: The isolated monoclonal urine-derived stem cells in this study were showed closer transcriptomic similarity to renal progenitor cells than to other mesenchymal stem cell types and possessed differential therapeutic effects on acute kidney injury. Full article

Background/Objectives: Periodontal diseases are highly prevalent worldwide, causing progressive destruction of the alveolar bone and eventual tooth loss when not treated. Despite advances in conventional periodontal therapies, complete tissue regeneration remains limited. This review aims to evaluate the efficacy, safety, and clinical relevance of stem cell-based tissue engineering approaches for regeneration of periodontal bone lesions. Methods: Following PRISMA guidelines, a systematic search was conducted across multiple databases, resulting in the inclusion of 17 studies in humans that met predefined PICO criteria. The study protocol was registered on PROSPERO (CRD420251229271). These studies assessed various stem cell sources, including dental and bone marrow-derived cells among others, both on their own and in combination with scaffolds or growth factors. Results: Most studies reported favorable outcomes in terms of clinical attachment gain, radiographic bone fill, probing depth reduction, and implant stability. No major adverse effects were noted, indicating good safety. However, results varied based on cell type, culture protocols, and defect characteristics. Conclusions: Stem cell therapy shows strong potential for periodontal regeneration, with outcomes that may potentially surpass those of conventional methods in selected cases. Further standardization, cost reduction, and long-term clinical trials are essential to confirm these findings and support their integration into daily dental practice. Full article

This study aims to compare the osteogenic potential of premixed hydraulic calcium silicate-based sealers (HCSSs) with an epoxy resin-based sealer in human bone marrow-derived stem cells (hBMSCs). Three HCSSs (White Endoseal MTA, One-Fil, EndoSequence BC Sealer) were compared with AH Plus Jet, an epoxy resin-based sealer. Disk-shaped specimens were prepared using sterilized Teflon tubes and immersed in osteogenic medium to create eluates. hBMSCs were cultured in each eluate, and osteogenic potential was assessed by alkaline phosphatase (ALP) activity (n = 6), Alizarin Red-S (ARS) staining (n = 6), quantitative real-time polymerase chain reaction (qPCR) (n = 3), and Western blot analysis. Statistical analyses were conducted using SPSS (version 24.0), with significance set at p < 0.05. All experimental groups exhibited higher ALP activity than the control on day 4. ARS staining of HCSSs differed significantly from AH Plus Jet on day 14 (p < 0.05), while White Endoseal MTA exhibited the highest intensity. qPCR revealed that EndoSequence BC Sealer induced the highest SMAD1 expression on day 4, while One-Fil and EndoSequence BC Sealer significantly upregulated RUNX2 expression compared with AH Plus Jet (p < 0.05). Western blotting confirmed that EndoSequence BC Sealer induced the highest RUNX2 protein expression. Collectively, premixed HCSSs promoted superior mineralization and RUNX2 expression compared to conventional resin-based sealer in hBMSCs. Full article

Background: Skeletal muscle laceration injuries remain a clinical challenge owing to limited and often delayed functional recovery. Surgical repair often fails to fully restore injured muscle, causing fibrosis and functional impairments. Mesenchymal stem cells (MSCs) represent a potential therapy due to their regenerative and immunomodulatory properties. However, their short-term regenerative effects in laceration injuries remain under-explored. Objective: We aim to evaluate the short-term effects of allogenic bone marrow-derived MSCs on skeletal muscle regeneration following laceration injury in rats. Methods: Sprague Dawley rats underwent laceration injury to the right gastrocnemius muscle and received local injection of either saline (n = 6) or allogeneic bone marrow-derived MSCs (2 × 10⁶ cells; n = 6) two weeks after injury. Muscle functional recovery was evaluated by measuring tetanic contraction force of the injured relative to the contralateral uninjured leg and compared among MSC-treated, saline-treated, untreated injured (n = 6), and intact control groups (n = 6) on days 7 and 14 post-treatment. Histological assessment of the treated muscle groups using Hematoxylin and Eosin and Masson’s Trichrome staining was conducted on day 7 post-treatment. Results: On day 7 post-treatment, MSC-treated muscle showed higher normalised force (96.8 ± 15.0%) than saline-treated (76.7 ± 4.6%) (p = 0.0393), but not untreated, muscle (83.1 ± 14.7%) (p = 0.2259). By day 14, the MSC-treated group exhibited significantly greater recovery of muscle force (110.8 ± 6.46%) than both the saline-treated (78.4 ± 6.47%) (p < 0.0001) and untreated groups (88.1 ± 3.41%) (p = 0.0001). Force recovery in the MSC-treated muscle was comparable to that in intact muscle (102.6 ± 10.4%) at both time points (p = 0.230). Supplementary histological analysis showed mild inflammatory cell infiltration, well-formed myoblasts, and a lower fibrosis index in MSC-treated muscle (29.30 ± 0.29%) compared with saline-treated muscle (31.77 ± 0.43%) (p < 0.0001) on day 7 post-treatment. Conclusions: Allogeneic bone marrow-derived MSC therapy is associated with enhanced repair of lacerated skeletal muscle over a short recovery period; however, larger studies with broader assessments are needed to confirm its potential clinical applicability. Full article

Although experimental evidence indicates that mitochondrial collapse is a common effect of both Chagas disease and post-ischemic heart failure and that cardiac anatomy and function are partially restored by stem cell therapy, the responsible molecular mechanisms are still under debate. Gene expression data from our publicly accessible transcriptomic dataset obtained by profiling the left ventricle myocardia of mouse models of Chagas disease and post-ischemic heart failure were re-analyzed from the perspective of the Genomic Fabric Paradigm. In addition to the regulation of the gene expression levels, we determined the changes in the strength of the homeostatic control of transcript abundance and the remodeling of the gene networks responsible for the mitochondrial respiration. The analysis revealed that most of the mitochondrial genes assigned to the five complexes of the respiratory chain were significantly downregulated by both Chagas disease and ischemia but exhibited outstanding recovery of the normal expression levels following direct injection of bone-marrow-derived stem cells. However, instead of regaining the original expression control and gene networking, the treatment induced novel mitochondrial arrangements, suggesting that multiple transcriptomic topologies might be compatible with any given physiological or pathological state. This study confirmed several established mechanisms and identified novel gene expression signals, especially Cox4i2, Cox6b1, Cox7b, Ndufb11, and Tmem186, that warrant further investigations. Their broad rescue with cell therapy underscores mitochondria as a convergent, tractable target for cardiac repair. Full article

Graphene-based nanomaterials, including graphene oxide (GO) and graphene quantum dots (GQDs), exhibit exceptional properties, which might facilitate the functional modification of TiO₂ nanotubes (NTs) for enhanced rapid osseointegration. This study investigated the effects of GO/GQD-deposited TiO₂-NTs on cell proliferation, osteogenic differentiation of rat bone marrow-derived mesenchymal stem cells (BMSCs), and early osseointegration in male 6-week-old Sprague Dawley (SD) rats. TiO₂-NTs (control group) were fabricated on titanium substrates via anodic oxidation. GO and GQDs were electrochemically deposited onto the TiO₂-NTs using cyclic voltammetry with 0.5 mg/mL GO and 0.1 mg/mL GQD dispersions to form NT-GO and NT-GQDs. In vitro assays evaluated cell adhesion, proliferation, and osteogenic differentiation. Implants were randomly inserted into one femoral epiphysis of nine rats (n = 3), and osseointegration was evaluated using micro-computed tomography and sequential fluorescence labeling at 2, 4, and 6 weeks post-implantation. Statistical analysis was conducted using ANOVA. Cyclic voltammetry successfully synthesized NT-GO and NT-GQDs, with Raman spectra confirming D and G bands. Both NT-GO and NT-GQDs exhibited superior cell adhesion, proliferation, and enhanced osteogenic differentiation compared with TiO₂-NTs. Notably, the NT-GQDs significantly promoted new bone formation in vivo. The integration of graphene nanomaterials onto TiO₂-NTs improves biocompatibility and accelerates osteogenesis, suggesting a promising strategy for enhancing osseointegration in orthopedic and dental implants. Full article

Background: T cell regeneration in the thymus is intrinsically linked to the T cell-biased lineage differentiation of hematopoietic stem and progenitor cells (HSPCs). Although nonhuman primates (NHPs) serve as indispensable models for studying thymic output under physiological and pathological conditions, a non-animal technology facilitating efficient TCR-selected T cell development and evaluating T cell output from NHP-derived HSPCs has been lacking. To address this gap, we established a rhesus macaque-specific artificial thymic organoid (RhATO) modeling primary thymus-tissue-free thymopoiesis. Methods: The RhATO was developed by expressing Rhesus macaque (RM) Delta-like Notch ligand 1 in mouse bone marrow stromal cell line (MS5-RhDLL1). The bone marrow-derived HSPCs were aggregated with MS5-RhDLL1 and cultured forming 3D artificial thymic organoids. These organoids were maintained under defined cytokine conditions to support complete T cell developmental ontogeny. T cell developmental progression was assessed by flow cytometry, and TCR-selected subsets were analyzed for phenotypic and functional properties. Results: RhATOs recapitulated the complete spectrum of thymopoietic events, including emergence of thymus-seeding progenitors, CD4⁺CD3⁻ immature single-positive and CD4⁺CD8⁺ double-positive early thymocytes, and mature CD4⁺ or CD8⁺ single-positive subsets. These subsets expressed CD38, consistent with the recent thymic emigrant phenotype, and closely mirrored canonical T cell ontogeny described in humans. RhATO-derived T cells were TCR-selected and demonstrated cytokine expression upon stimulation. Conclusions: This study provides the first demonstration of an NHP-specific artificial thymic technology that faithfully models thymopoiesis. RhATO represents a versatile ex vivo platform for studying T cell development, immunopathogenesis, and generating TCR selected T cells. Full article

Galactic cosmic ray (GCR) radiation is a major barrier to human space exploration beyond Earth’s magnetic field protection. Mesenchymal stem cells (MSCs) are found in all organs and play a critical role in repair and regeneration of tissue. We engineered bone marrow-derived MSCs and evaluated their response to ionizing radiation exposure. Epidermal growth factor receptor (EGFR) expression by certain types of cancers has been shown to induce radioresistance. In this study, we tested the feasibility of transfecting MSCs to overexpress EGFR (eMSC-EGFR) and their capacity to tolerate and recover from X-ray exposure. Quantitative real-time PCR (qRT-PCR) and immunoblotting results confirmed the efficient transfection of EGFR into MSCs and EGFR protein production. eMSC-EGFR maintained characteristics of human MSCs as outlined by the International Society for Cell & Gene Therapy. Then, engineered MSCs were exposed to various dose rates of X-ray (1–20 Gy) to assess the potential radioprotective role of EGFR overexpression in MSCs. Post-irradiation analysis included evaluation of morphology, cell proliferation, viability, tumorigenic potential, and DNA damage. eMSC-EGFR showed signs of radioresistance compared to naïve MSCs when assessing relative proliferation one week following exposure to 1–8 Gy X-rays, and significantly lower DNA damage content 24 h after exposure to 4 Gy. We establish for the first time the efficient generation of EGFR overexpressing MSCs as a model for enhancing the human body to tolerate and recover from moderate dose radiation injury in long-term manned space travel. Full article

Mesenchymal stem cells (MSCs) exhibit therapeutic properties, which have been attributed to their secretome, the set of secreted factors comprising cytokines, growth factors, and extracellular vesicles (EVs). In particular, small extracellular vesicles (sEVs) or exosomes, ranging between 30 nm and 120 nm in diameter, can target specific tissues to deliver molecular payloads, thus lending themselves as promising platform for cell-free therapies. In this study, sEVs were purified from the conditioned medium (CM) harvested from human bone marrow-derived MSC culture and purified using size-exclusion chromatography (SEC) or density gradient ultracentrifugation (DG-UC). Then sEVs were fully characterized for identity and integrity using multiple analytical methods, including single-particle, transcriptomic and proteomic analyses. Different in vitro cell-based assays were established to evaluate the biological effects of the purified sEVs. Specifically, scratch wound healing and tube formation assays using human umbilical vein endothelial cells (HUVECs) were used to evaluate the regenerative properties of MSC-sEVs. Our findings demonstrated that the in vitro functional properties of MSC-sEVs are correlated with sEVs’ purity levels obtained by different purification methods. Full article

Bio-based photo-crosslinkable hydrogels are used in tissue engineering as three-dimensional printable scaffolds due to their functional and biological similarities with the extracellular matrix (ECM). In this work, emerging bioink candidates such as chitosan, alginate and gelatin-based photo-crosslinkable hydrogel were developed using extrusion-based 3D printing to establish a better understanding of their applicability. The polymers were methacrylated by the same methacrylation reaction pathway, which enabled successful light-induced 3D printing. Morphology, swelling (6–40%), mechanical (Young’s modulus, 0.1–0.5 KPa) and rheological properties (300–1000 Pa), degradation kinetics (10->60 days) and printability of the gels were also characterized in identical conditions for the first time. 3D-printability results indicated that methacrylated gelatin enhanced printability, shape fidelity and integrity of printed structures compared to methacrylated alginate, which presents structural instability and poorer printing control due to its low crosslink density. Moreover, cell attachment and Live/Dead assays using bone marrow-derived mesenchymal stem cells (BM-MSCs) showed that all formulations have good biocompatibility for use as scaffolds. Specifically, gelatin-based hydrogels showed a higher level of BM-MSCs attachment and spreading than the other types of hydrogels. Overall, our results suggest that the hydrogels based on these three biopolymers present good potential as a biomaterial for light-induced extrusion-based 3D printing. Full article

Background/Objectives: Non-ischemic cardiomyopathy (NICM) refers to myocardial disease characterized by structural and functional impairment without coronary artery disease. Stem cell therapy has emerged as a potential treatment to restore heart function in NICM, but clinical results have been inconsistent. Methods: This meta-analysis comprises five randomized controlled trials with a total of 302 patients, retrieved from PubMed, ScienceDirect, the Cochrane Library, and SAGE Journals. Results: Compared with the control group, stem cell therapy group showed significant improvements in the left ventricular ejection fraction (LVEF) at the 3-month follow-up (MD = 4.55, 95% CI 2.12–6.98, p = 0.0002), a reduction in the left ventricular end-diastolic diameter (LVEDD) at the 3-month follow-up (MD = −3.83, 95% CI −7.27 to −0.39, p = 0.03) and an improvement in the New York Heart Association (NYHA) functional class both at 3 months (MD = −0.58 95% CI −0.97 to −0.19, p = 0.004) and 12 months (MD = −0.49 95% CI −0.91 to −0.07, p = 0.02). Additionally, there was a significant decrease in the Minnesota Living with Heart Failure Questionnaire (MLHFQ) score at the 6-month follow-up (MD = −14.05, 95% CI −25.97 to −2.13, p = 0.021). However, no significant differences were observed in the left ventricular end-diastolic volume (LVEDV), left ventricular end-systolic volume (LVESV), 6-min walk test (6-MWT), or major adverse cardiovascular events (MACEs) between the two groups. Conclusions: Bone marrow-derived stem cell therapy could be a promising and safe method to improve cardiac function and quality of life in patients with NICM. Further large-scale randomized controlled trials are needed to validate these findings. Full article

Megakaryocytes (MKs) have traditionally been viewed as terminal hematopoietic cells responsible solely for platelet production. However, recent advances in imaging and single-cell transcriptomics have revealed substantial heterogeneity among MK populations and diverse functions beyond thrombopoiesis. MKs actively participate in innate and adaptive immunity, modulate the hematopoietic stem cell (HSC) niche, and adapt to physiological and pathological stimuli. Located in distinct anatomical sites such as bone marrow and lung, MKs exhibit compartment-specific specializations that enable them to serve as critical integrators of hemostatic, immune, and regenerative processes. Experimental models using human pluripotent stem cells and inducible MKs have enhanced mechanistic insights, while innovative bioreactor platforms and xenotransplantation strategies advance translational applications in platelet production and therapy. Furthermore, immune MK subsets derived from pluripotent stem cells show promising therapeutic potential for modulating inflammation and autoimmune diseases. Continued exploration of MK diversity, tissue-specific roles, and intercellular communication will unlock new opportunities for leveraging MK plasticity in regenerative medicine, immunotherapy, and hematologic disorders, repositioning these versatile cells as central players in systemic homeostasis and defense. Full article

Leukemia stem cells (LSCs) in numerous hematologic malignancies are generally believed to be responsible for disease initiation, progression/relapse and resistance to chemotherapy. It has been shown that non-leukemic hematopoietic cells are affected molecularly and biologically by leukemia cells in the same bone marrow environment where both non-leukemic hematopoietic stem cells (HSCs) and LSCs reside. We believe the molecular and biological changes of these non-leukemic HSCs should be accompanied by the morphological changes of these cells. On the other hand, the quantity of these non-leukemic HSCs with morphological changes should reflect disease severity, prognosis and therapy responses. Thus, identification of non-leukemic HSCs in the leukemia bone marrow environment and monitoring of their quantity before, during and after treatments will potentially provide valuable information for correctly handling treatment plans and predicting outcomes. However, we have known that these morphological changes at the stem cell level cannot be extracted and identified by microscopic visualization with human eyes. In this study, we chose polycythemia vera (PV) as a disease model (a type of human myeloproliferative neoplasms derived from a hematopoietic stem cell harboring the JAK2V617F oncogene) to determine whether we can use artificial intelligence (AI) deep learning to identify and quantify non-leukemic HSCs obtained from bone marrow of JAK2V617F knock-in PV mice by analyzing single-cell images. We find that non-JAK2V617F-expressing HSCs are distinguishable from LSCs in the same bone marrow environment by AI with high accuracy (>96%). More importantly, we find that non-JAK2V617F-expressing HSCs from the leukemia bone marrow environment of PV mice are morphologically distinct from normal HSCs from a normal bone marrow environment of normal mice by AI with an accuracy of greater than 98%. These results help us prove the concept that non-leukemic HSCs undergo AI-recognizable morphological changes in the leukemia bone marrow environment and possess unique morphological features distinguishable from normal HSCs, providing a possibility to assess therapy responses and disease prognosis through identifying and quantitating these non-leukemic HSCs in patients. Full article

Extracellular vesicles (EVs) express features of parental cells and are fundamental in modulating the crosstalk between cancer cells and their environment. Increasing evidence suggests that EVs have a pivotal role in tumorigenesis, cancer development, and drug resistance. EVs are also involved in controlling the communication between hematopoietic stem cells and the surrounding microenvironment in the bone marrow (BM), during several processes such as self-renewal, mobilization, and lineage differentiation. Proteins expressed in cancer cell-derived EVs can be useful to further understand the regulation of hematopoietic stem cell fate, a fundamental mechanism in acute myeloid leukemia (AML). Furthermore, EVs are implicated in transmitting drug-resistance mechanisms in solid and not-solid cancer types. Here, using a proteomic approach, we analyze and validate the protein profile of EVs from three AML cell lines with different genotypes, namely OCI-AML-2, OCI-AML-3, and HL-60. The majority of the identified proteins were significantly enriched in the Gene Ontology category ‘Extracellular Exosome’. Network model analysis of EV proteins revealed several significantly modulated pathways, including inflammation activation and metastatic processes in AML cell-derived EVs. The EVs proteomic profiling allows us to identify the EVs-associated molecules and pathways that could impact cancer progression and drug resistance. Full article