Bone Marrow-derived Mesenchymal Stem Cells Research Articles

Antineoplastic therapy affects the in vitro phenotype and functionality of healthy human bone marrow-derived mesenchymal stromal cells

AbstractWhile antineoplastic therapies aim to specifically target cancer cells, they may also exert adverse effects on healthy tissues, like healthy hematopoietic stem and progenitor cells (HSPC), leading to hematotoxicity as a common side effect. Mesenchymal stromal cells (MSC) are a major component of the bone marrow (BM) microenvironment, regulating normal hematopoiesis, while their susceptibility to anticancer therapies and contribution to therapy-related hematotoxicity remains largely unexplored. To address this, we investigated the effects of etoposide, temozolomide, 5-azacitidine, and venetoclax on healthy BM-derived MSC functionality. Doses below therapeutic effects of etoposide (0.1–0.25 µM) inhibited cellular growth and induced cellular senescence in healthy MSC, accompanied by an increased mRNA expression of CDKN1A, decreased trilineage differentiation capacity, and insufficient hematopoietic support. Pharmacological doses of 5-azacitidine (2.5 µM) shifted MSC differentiation capacity by inhibiting osteogenic capacity but enhancing the chondrogenic lineage, as demonstrated by histochemical staining and on mRNA level. At the highest clinically relevant dose, neither venetoclax (40 nM) nor temozolomide (100 µM) exerted any effects on MSC but clearly inhibited cellular growth of cancer cell lines and primary healthy HSPC, pointing to damage to hematopoietic cells as a major driver of hematotoxicity of these two compounds. Our findings show that besides HSPC, also MSC are sensitive to certain antineoplastic agents, resulting in molecular and functional alterations that may contribute to therapy-related myelosuppression. Understanding these interactions could be helpful for the development of strategies to preserve BM MSC functionality during different kinds of anticancer therapies.

Human-Brain-Derived Ischemia-Induced Stem Cell Transplantation Is Associated with a Greater Neurological Functional Improvement Compared with Human-Bone Marrow-Derived Mesenchymal Stem Cell Transplantation in Mice After Stroke

The transplantation of injury/ischemia-induced stem cells (iSCs) extracted from post-stroke human brains can improve the neurological functions of mice after stroke. However, the usefulness of iSCs as an alternative stem cell source remains unclear. The current study aimed to assess the efficacy of iSC and mesenchymal stem cell (MSC) transplantation. In this experiment, equal numbers of human brain-derived iSCs (h-iSCs) (5.0 × 104 cells/μL) and human bone marrow-derived MSCs (h-MSCs) (5.0 × 104 cells/μL) were intracranially transplanted into post-stroke mouse brains after middle cerebral artery occlusion. Results showed that not only h-iSC transplantation but also h-MSC transplantation activated endogenous neural stem/progenitor cells (NSPCs) around the grafted sites and promoted neurological functional improvement. However, mice that received h-iSC transplantation experienced improvement in a higher number of behavioral tasks compared with those that received h-MSC transplantation. To investigate the underlying mechanism, NSPCs extracted from the ischemic areas of post-stroke mouse brains were cocultured with h-iSCs or h-MSCs. After coincubation, NSPCs, h-iSCs, and h-MSCs were selectively collected via fluorescence-activated cell sorting. Next, their traits were analyzed via microarray analysis. The genes related to various neuronal lineages in NSPCs after coincubation with h-iSCs were enriched compared with those in NSPCs after coincubation with h-MSCs. In addition, the gene expression patterns of h-iSCs relative to those of h-MSCs showed that the expression of genes related to synapse formation and neurotransmitter-producing neurons increased more after coincubation with NSPCs. Hence, cell–cell interactions with NSPCs promoted transdifferentiation toward functional neurons predominantly in h-iSCs. In accordance with these findings, immunohistochemistry showed that the number of neuronal networks between NSPCs and h-iSCs was higher than that between NSPCs and h-MSCs. Therefore, compared with h-MSC transplantation, h-iSC transplantation is associated with a higher neurological functional improvement, presumably by more effectively modulating the fates of endogenous NSPCs and grafted h-iSCs themselves.

Post-symptomatic administration of hMSCs exerts therapeutic effects in SCA2 mice

BackgroundDefects in the ataxin-2 (ATXN-2) protein and CAG trinucleotide repeat expansion in its coding gene, Atxn-2, cause the neurodegenerative disorder spinocerebellar ataxia type 2 (SCA2). While clinical studies suggest potential benefits of human-derived mesenchymal stem cells (hMSCs) for treating various ataxias, the exact mechanisms underlying their therapeutic effects and interaction with host tissue to stimulate neurotrophin expression remain unclear specifically in the context of SCA2.MethodsHuman bone marrow-derived MSCs (hMSCs) were injected into the cisterna magna of 26-week-old wild-type and SCA2 mice. Mice were assessed for impaired motor coordination using the accelerating rotarod, open field test, and composite phenotype scoring. At 50 weeks, the cerebellum vermis was harvested for protein assessment and immunohistochemical analysis.ResultsSignificant loss of NeuN and calbindin was observed in 25-week-old SCA2 mice. However, after receiving multiple injections of hMSCs starting at 26 weeks of age, these mice exhibited a significant improvement in abnormal motor performance and a protective effect on Purkinje cells. This beneficial effect persisted until the mice reached 50 weeks of age, at which point they were sacrificed to study further mechanistic events triggered by the administration of hMSCs. Calbindin-positive cells in the Purkinje cell layer expressed bone-derived neurotrophic factor after hMSC administration, contributing to the protection of cerebellar neurons from cell death.ConclusionIn conclusion, repeated administration of hMSCs shows promise in alleviating SCA2 symptoms by preserving Purkinje cells, improving neurotrophic support, and reducing inflammation, ultimately leading to the preservation of locomotor function in SCA2 mice.

Effect of chondroitin sulfate and bone marrow-derived mesenchymal stem cells on intervertebral disc degeneration treatment in rabbits

The present study evaluated the influence of bone marrow-derived stem cells (BM-SC) and chondroitin sulfate (CS) on histological changes in intervertebral disc (IVD). A randomized clinical trial was conducted, thirty-six healthy New Zealand rabbits were randomly distributed into four different groups (n=9): con-trol group (A), stem cell group (B), chondroitin sulfate group (C), and associa-tion of stem cells with chondroitin sulfate group (D). All animals underwent the experimental disc degeneration procedure. Group A received two intradiscal applications of DEM (Dulbecco’s modified eagle’s medium), one and two weeks after intervertebral disc degeneration (IVDD), while group B received two intradiscal applications of 1.2 x 106 BM-SC at the same time interval as group A. After IVDD, group C received eight subcutaneous applications of CS at a dose of 5 mg/kg, one application every seven days. In contrast, group D received the association of the techniques used in groups B and C. Sixty days after the end of the interventions, all animals were euthanized, then the crani-ocaudal thickness of the IVD was measured, and IVDD was classified in scores according to the histological grading model. All groups that received CS had thicker IVDs, and all the treated groups presented better scores on several items and a better overall score. It was possible to conclude that in the species studied, the isolated use of CS or BM-SC was statistically significant in improv-ing the histopathological aspects of IVDD, however, the combination of treat-ments did not prove to be more efficient.

Novel Gene Biomarkers Specific to Human Mesenchymal Stem Cells Isolated from Bone Marrow

In this paper, we present a comparative analysis of the transcriptomic profile of three different human cell types: hematopoietic stem cells (HSCs), bone marrow-derived mesenchymal stem cells (MSCs) and fibroblasts (FIBs). The work aims to identify unique genes that are differentially expressed as specific markers of bone marrow-derived MSCs, and to achieve this undertakes a detailed analysis of three independent datasets that include quantification of the global gene expression profiles of three primary cell types: HSCs, MSCs and FIBs. A robust bioinformatics method, called GlobalTest, is used to assess the specific association between one or more genes expressed in a sample and the outcome variable, that is, the ‘cell type’ provided as a single univariate response. This outcome variable is predicted for each sample tested, based on the expression profile of the specific genes that are used as input to the test. The precision of the tests is calculated along with the statistical sensitivity and specificity for each gene in each dataset, yielding four genes that mark MSCs with high accuracy. Among these, the best performer is the protein-coding gene Transgelin (TAGLN, Gene ID: 6876) (with a Positive Predictive Value > 0.96 and FDR < 0.001), which identifies MSCs better than any of the currently used standard markers: ENG (CD105), THY1 (CD90) or NT5E (CD73). The results are validated by RT-qPCR, providing novel gene biomarkers specific for human MSCs.

Deciphering transcriptome patterns in porcine mesenchymal stem cells promoting phenotypic maintenance and differentiation by key driver genes

Mesenchymal stem cells (MSC) are fibroblast-like non-hematopoietic cells with self-renewal and differentiation capacity, and thereby great potential in regeneration and wound healing. MSC populations are heterogeneous not only inherently, but also among different model species. In particular, porcine MSC serve as a frequently used resource for translational research, due to pigs’ distinctive closeness to human anatomy and physiology. However, information on gene expression profiles from porcine MSC and its dynamics during differentiation is sparse, especially with regard to cell surface and inner cell markers. In this study, we investigated the transcriptome of bone marrow-derived MSC and its differentiated cell types in a minipig breed for experimental research, known as Mini-LEWE, using bulk mRNA sequencing. Our data highlighted Rap1 signaling and downstream pathways PI3K-Akt and MAPK signaling as potential players for the maintenance of stemness of BM-MSC. In addition, we were able to link the process of differentiation to changes in the regulation of actin cytoskeleton. A total of 18 “BM-MSC differentiation driver markers” were identified, potentially promoting the process of differentiation into adipocytes, chondrocytes as well as osteocytes. Our results offer a new perspective on the molecular phenotype of porcine BM-MSC and the transcriptional responses in new differentiated progeny.

The VEGF-Mediated Cytoprotective Ability of MIF-Licensed Mesenchymal Stromal Cells in House Dust Mite-Induced Epithelial Damage.

Enhancing mesenchymal stromal cell (MSC) therapeutic efficacy through licensing with proinflammatory cytokines is now well established. We have previously shown that macrophage migration inhibitory factor (MIF)-licensed MSCs exerted significantly enhanced therapeutic efficacy in reducing inflammation in house dust mite (HDM)-driven allergic asthma. Soluble mediators released into the MSC secretome boast cytoprotective properties equal to those associated with the cell itself. In asthma, epithelial barrier damage caused by the inhalation of allergens like HDM drives goblet cell hyperplasia. Vascular endothelial growth factor (VEGF) plays a pivotal role in the repair and maintenance of airway epithelial integrity. Human bone marrow-derived MSCs expressed the MIF receptors CD74, CXCR2, and CXCR4. Endogenous MIF from high MIF expressing CATT7 bone marrow-derived macrophages increased MSC production of VEGF through the MIF CXCR4 chemokine receptor, where preincubation with CXCR4 inhibitor mitigated this effect. CATT7-MIF licensed MSC conditioned media containing increased levels of VEGF significantly enhanced bronchial epithelial wound healing via migration and proliferation in vitro. Blocking VEGFR2 or theuse of mitomycin C abrogated this effect. Furthermore, CATT7-MIF MSC CM significantly decreased goblet cell hyperplasia after the HDM challenge in vivo. This was confirmed to be VEGF-dependent, as the use of anti-human VEGF neutralising antibody abrogated this effect. Overall, this study highlights that MIF-licenced MSCs show enhanced production of VEGF, which has the capacity to repair the lung epithelium.

An Update on Emerging Regenerative Medicine Applications: The Use of Extracellular Vesicles and Exosomes for the Management of Chronic Pain.

Chronic pain affects nearly two billion people worldwide, surpassing heart disease, diabetes, and cancer in terms of economic costs. Lower back pain alone is the leading cause of years lived with disability worldwide. Despite limited treatment options, regenerative medicine, particularly extracellular vesicles (EVs) and exosomes, holds early promise for patients who have exhausted other treatment options. EVs, including exosomes, are nano-sized structures released by cells, facilitating cellular communication through bioactive molecule transfer, and offering potential regenerative properties to damaged tissues. Here, we review the potential of EVs and exosomes for the management of chronic pain. In osteoarthritis, various exosomes, such as those derived from synovial mesenchymal stem cells, human placental cells, dental pulp stem cells, and bone marrow-derived mesenchymal stem cells (MSCs), demonstrate the ability to reduce inflammation, promote tissue repair, and alleviate pain in animal models. In intervertebral disc disease, Wharton's jelly MSC-derived EVs enhance cell viability and reduce inflammation. In addition, various forms of exosomes have been shown to reduce signs of inflammation in neurons and alleviate pain in neuropathic conditions in animal models. Although clinical applications of EVs and exosomes are still in the early clinical stages, they offer immense potential in the future management of chronic pain conditions. Clinical trials are ongoing to explore their therapeutic potential further, and with more research the potential applicability of EVs and exosomes will be fully understood.

Culture Expansion Alters Human Bone Marrow Derived Mesenchymal Stem Cell Production of Osteoarthritis-relevant Cytokines and Growth Factors

PurposeThe purposes of this study were to characterize the human bone marrow derived mesenchymal stem cells (BM-MSCs) production of osteoarthritis-relevant cytokines and growth factors as they are purified and multiplied, a process termed culture expansion, and to compare the immunomodulatory potential of BM-MSCs based on source and medium used for culture expansion. MethodsBM-MSCs were obtained from iliac crest bone marrow aspirates of four healthy donors. These four BM-MSC cell lines underwent four rounds, or “passages,” of the institutional culture expansion protocol, using institutional culture media. The secretory molecules known to play a role in OA-related inflammatory immune response, cartilage degradation and patient symptoms, together called the BM-MSC “secretome,” were measured at each passage. Three lines of commercially available BM-MSCs from healthy donors underwent culture expansion by the same protocol, using commercial culture media. The commercial BM-MSCs secretome and the institutional BM-MSCs secretome were compared at each passage. Significance was set at p<0.05. ResultsInstitutional BM-MSCs produced less IL-6 at passages 3 (237±113 pg/mL) and 4 (237±113 pg/mL) compared to passages 1 (884±97 pg/mL) and 2 (1071±129 pg/mL; p<0.01). Institutional BM-MSCs produced more MIP-3α at passage 4 than at passage 1 (106±41 vs 32±7 pg/mL; p<0.01). Across passages of culture expansion, institutional BM-MSCs grown on institutional medium expressed more IL-6 (P<0.001), IL-10 (P<0.001), IL-1β (P<0.001), TNFα (P=0.004), and VEGF-C (P=0.003) than commercially available BM-MSCs grown on commercial medium. ConclusionCulture expansion alters key molecules within the BM-MSC secretome. Additionally, differences in BM-MSC source and culture medium alter the BM-MSC secretome and its immunomodulatory potential.

Naringin promotes osteogenic potential in bone marrow-derived mesenchymal stem cells via mediation of miR-26a/Ski axis

BackgroundOsteonecrosis of the femoral head (ONFH) is a common orthopedic disease, which seriously affects the quality of life of patients. Naringin has protective effect on ONFH. In present study, we aimed to investigate the mechanism of Naringin regulating miR-26a in ONFH. MethodsTwo sequencing datasets (GSE89587 for micro-RNA, GSE123568 for mRNA) related to ONFH were obtained from the GEO database for bioinformatics analysis. Bone marrow-derived mesenchymal stem cells (BMSCs) were treated with adipogenic medium (AM) or osteogenic medium (OM), and then treated with 10 μM, 100 μM or 1000 μM Naringin. Gene and protein levels were detected by RT-qPCR and Western blotting. ALP activity and alizarin red staining (ARS) were applied to investigate the osteogenic differentiation of BMSCs. Oil red O staining was performed to test adipogenic differentiation. The content of triglycerides (TG) in BMSCs was detected by TG detection kit. Double luciferase reporter gene measured the interaction between miR-26a and Ski. ResultsBioinfomatic analyses indicated a significant downregulation of miR-26a and a significant upregulation of Ski in the peripheral blood of patients with ONFH. Naringin significantly promoted the osteogenic differentiation, and increased the ALP activity and ARS. Meanwhile, it decreased the adipogenic differentiation and inhibited TG levels. In addition, miR-26a was downregulated and Ski was increased in AM-treated BMSCs, while miR-26a was upregulated and Ski was decreased in OM-treated BMSCs. Furthermore, miR-26a promoted the osteogenic differentiation and suppressed the adipogenic differentiation in BMSCs. Moreover, Naringin enhanced osteogenic potential in BMSCs was reversed by knockdown of miR-26a or overexpression of Ski. ConclusionNaringin could promote osteogenic differentiation of BMSCs via mediation of miR-26a/Ski axis. Thereby, Naringin might be a new agent for ONFH treatment.

Multi-omics Data Integration Analysis Identified Therapeutic Targets and Potential Reuse Drugs for Osteoporosis.

To facilitate drug discovery and development for the treatment of osteoporosis. With global aging, osteoporosis has become a common problem threatening the health of the elderly. It is of important clinical value to explore new targets for drug intervention and develop promising drugs for the treatment of osteoporosis. To understand the major molecules that mediate the communication between the cell populations of bone marrow-derived mesenchymal stem cells (BM-MSCs) in osteoporosis and osteoarthritis patients and identify potential reusable drugs for the treatment of osteoporosis. Single-cell RNA sequencing (scRNA-seq) data of BM-MSCs in GSE147287 dataset were classified using the Seurat package. CellChat was devoted to analyzing the ligand-receptor pairs (LR pairs) contributing to the communication between BM-MSCs subsets. The LR pairs that were differentially expressed between osteoporosis samples and control samples and significantly correlated with immune score were screened in the GSE35959 dataset, and the differentially expressed gene in both GSE35959 and GSE13850 data sets were identified as targets from a single ligand or receptor. The therapeutic drugs for osteoporosis were screened by network proximity method, and the top-ranked drugs were selected for molecular docking and molecular dynamics simulation with the target targets. Twelve subsets of BM-MSCs were identified, of which CD45-BM-MSCS_4, CD45-BM- MSCS_5, and CD45+ BM-MSCs_5 subsets showed significantly different distributions between osteoporosis samples and osteoarthritis samples. Six LR pairs were identified in the bidirectional communication between these three BM-MSCs subsets and other BM-MSCs subsets. Among them, MIF-CD74 and ITGB2-ICAM2 were significantly correlated with the immune score. CD74 was identified as the target, and a total of 48 drugs targeting CD47 protein were identified. Among them, DB01940 had the lowest free energy binding score with CD74 protein and the binding state was very stable. This study provided a new network-based framework for drug reuse and identified initial insights into therapeutic agents targeting CD74 in osteoporosis, which may be meaningful for promoting the development of osteoporosis treatment.

Enhancing intrinsic TGF-β signaling via heparan sulfate glycosaminoglycan regulation to promote mesenchymal stem cell capabilities and chondrogenesis for cartilage repair

Osteoarthritis burdens patients due to the limited regenerative capacity of chondrocytes. Traditional cartilage repair often falls short, necessitating innovative approaches. Mesenchymal stem cells (MSCs) show promise for regeneration. Heparan sulfate glycosaminoglycans (HS-GAGs) regulate cellular functions, making them a target for cartilage repair. This study highlights how Heparinase III (HepIII) cleaves intact HS-GAGs in bone marrow-derived MSCs (BM-MSCs), enhancing their capabilities and specifically promoting chondrogenesis. HepIII-treated BM-MSCs cultured in a hanging drop device for three days, significantly increased cell number and aggregation into a cell sphere with early chondrogenesis. HepIII promoted BM-MSCs toward chondrogenesis, increasing type II collagen, intact HS-GAGs, and sulfated GAG content, while upregulating chondrogenic and heparan sulfate proteoglycan genes. Treatment with the TGF-β inhibitor (SB-431542) in HepIII-treated BM-MSCs demonstrated enhanced intrinsic transforming growth factor-β (TGF-β) signaling and fibronectin expression. This approach also boosted BM-MSC self-renewal, immunosuppressive potential, and modified acetylated histone signatures, offering a cost-effective strategy for cartilage repair by addressing inflammation, metabolic changes, and the high costs of traditional TGF-β methods. From the results, HepIII-treated BM-MSCs show potential for use in combination with other biopolymers as injectable gels to improve cartilage repair in osteoarthritis patients in the near future.

A new paradigm of bone active risedronate-functionalized polycaprolactone/gelatin scaffold synergistically promotes osteogenic differentiation in rat bone marrow-derived mesenchymal stem cells for bone tissue engineering

Modern developments in bone tissue engineering focus on designing biomimetic materials that exhibit suitable mechanical and physiochemical properties. In this study, we present the development of a new biomaterial scaffold using a newly constructed polymer that contains bisphosphonate in combination with gelatin (GAT). To achieve scaffolding, a chemical grafting technique was used to develop risedronate (RS)-functionalized polycaprolactone (PCL-RS). The freeze-casting process was used to construct the porous PCL-RS/GAT scaffold after incorporating gelatin into the PCL-RS polymer solution. A scaffold with pores that are in perfect position and a porosity of 81.84% was successfully acquired. The biodegradability assessment, 48% of its early weight was lost after five weeks. The PCL-RS/GAT scaffold exhibited an elastic modulus of 32.01 MPa and a tensile strength of 3.9 MPa. The MTT analysis showed the PCL-RS/GAT favorable cytocompatibility with rat bone marrow-derived mesenchymal stem cells (BM-MSC). In addition, the cells cultured in the PCL-RS/GAT scaffold exhibited the greatest ALP activity and mineralization. The RT-PCR test results indicated that the PCL-RS/GAT scaffold had a high RUNX2, COL 1A1, and OCN gene expression, suggesting a strong osteoinductive capacity. The results indicate that the PCL-RS/GAT scaffold is a suitable biomimetic platform for tissue engineering in bone.

Early anti-inflammatory polarization of macrophages ameliorates post-surgical inflammation and osseointegration around titanium implants in mice

Dental implants are considered a superior option for the replacement of missing teeth. However, the invasive nature of the surgical procedure often results in significant postoperative inflammation, and the prolonged healing period of 3 to 6 months presents a notable disadvantage. High mobility group box 1 (HMGB1) is a critical mediator of acute inflammation following surgical injury, which can hinder the onset of osseointegration. This study aims to examine whether the inhibition of HMGB1 can mitigate acute inflammation and subsequently enhance osseointegration. The findings indicate that HMGB1 inhibition markedly reduces inflammation and promotes bone repair in murine models. Further in vitro investigations into the regulatory mechanisms of HMGB1 in macrophages reveal its role in increasing Yes-associated protein (YAP) activity, which contributes to pro-inflammatory polarization. Additionally, conditioned media derived from macrophages influenced by HMGB1 significantly impair the migratory and osteogenic capabilities of bone marrow-derived mesenchymal stem cells, which are essential for bone regeneration. In vivo experiments further validate that the administration of exogenous HMGB1 exacerbates postoperative acute inflammation and obstructs osseointegration. The study concludes that inhibiting HMGB1 fosters an anti-inflammatory polarization of macrophages, leading to diminished postoperative acute inflammation and expedited osseointegration around dental implants in mice.

Impact of Porosity and Stiffness of 3D Printed Polycaprolactone Scaffolds on Osteogenic Differentiation of Human Mesenchymal Stromal Cells and Activation of Dendritic Cells.

Despite the potential of extrusion-based printing of thermoplastic polymers in bone tissue engineering, the inherent nonporous stiff nature of the printed filaments may elicit immune responses that influence bone regeneration. In this study, bone scaffolds made of polycaprolactone (PCL) filaments with different internal microporosity and stiffness was 3D-printed. It was achieved by combining three fabrication techniques, salt leaching and 3D printing at either low or high temperatures (LT/HT) with or without nonsolvent induced phase separation (NIPS). Printing PCL at HT resulted in stiff scaffolds (modulus of elasticity (E): 403 ± 19 MPa and strain: 6.6 ± 0.1%), while NIPS-based printing at LT produced less stiff and highly flexible scaffolds (E: 53 ± 10 MPa and strain: 435 ± 105%). Moreover, the introduction of porosity by salt leaching in the printed filaments significantly changed the mechanical properties and degradation rate of the scaffolds. Furthermore, this study aimed to show how these variations influence proliferation and osteogenic differentiation of human bone marrow-derived mesenchymal stromal cells (hBMSC) and the maturation and activation of human monocyte-derived dendritic cells (Mo-DC). The cytocompatibility of the printed scaffolds was confirmed by live-dead imaging, metabolic activity measurement, and the continuous proliferation of hBMSC over 14 days. While all scaffolds facilitated the expression of osteogenic markers (RUNX2 and Collagen I) from hBMSC as detected through immunofluorescence staining, the variation in porosity and stiffness notably influenced the early and late mineralization. Furthermore, the flexible LT scaffolds, with porosity induced by NIPS and salt leaching, stimulated Mo-DC to adopt a pro-inflammatory phenotype marked by a significant increase in the expression of IL1B and TNF genes, alongside decreased expression of anti-inflammatory markers, IL10 and TGF1B. Altogether, the results of the current study demonstrate the importance of tailoring porosity and stiffness of PCL scaffolds to direct their biological performance toward a more immune-mediated bone healing process.

Identification of CD141+vasculogenic precursor cells from human bone marrow and their endothelial engagement in the arteriogenesis by co-transplantation with mesenchymal stem cells

BackgroundCritical limb ischemia (CLI) is a condition characterized by insufficient blood flow to the lower limbs, resulting in severe ischemia and potentially leading to amputation. This study aims to identify novel vasculogenic precursor cells (VPCs) in human bone marrow and evaluate their efficacy in combination with bone marrow-derived mesenchymal stem cells (BM-MSCs) for the treatment of CLI.MethodsEx vivo cultured VPCs and BM-MSCs from bone marrow were characterized and their effects on neovascularization and long-term tissue regeneration were tested in a mouse CLI model.ResultsVPCs, expressing high levels of hepatocyte growth factor and c-MET, were identified from human bone marrow aspirates. These cells exhibited strong vasculogenic capacity in vitro but possessed a cellular phenotype distinct from those of previously reported endothelial precursor cells in circulation or cord blood. They also expressed most surface markers of BM-MSCs and demonstrated multipotent differentiation ability. Screening of 376 surface markers revealed that VPCs uniquely display CD141 (thrombomodulin). CD141+VPCs are present in BM aspirates as a rare population and can be expanded ex vivo with a population doubling time of approximately 20 h, generating an elaborate vascular network even under angiogenic factor-deficient conditions and recruiting BM-MSCs to the network as pericyte-like cells. Intramuscular transplantation of a combination of human CD141+VPCs and BM-MSCs at a ratio of 2:1 resulted in limb salvage, blood flow recovery, and regeneration of large vessels in the femoral artery-removed CLI model, with an efficacy superior to that of singular transplantation. Importantly, large arteries and arterioles in dual cell transplantation expressed human CD31 in the intima and human α-smooth muscle actin in media layer at 4 and 12 weeks, likely indicating their lineage commitment to endothelial cells and vascular smooth muscle, respectively, in vivo.ConclusionDual-cell therapy using BM-derived CD141+ VPCs and BM-MSCs holds potential for further development in clinical trials to treat peripheral artery disease and diabetic ulcers.

Equine bone marrow-derived mesenchymal stromal cells reduce established S. aureus and E. coli biofilm matrix in vitro.

Biofilms reduce antibiotic efficacy and lead to complications and mortality in human and equine patients with orthopedic infections. Equine bone marrow-derived mesenchymal stromal cells (MSC) kill planktonic bacteria and prevent biofilm formation, but their ability to disrupt established orthopedic biofilms is unknown. Our objective was to evaluate the ability of MSC to reduce established S. aureus or E. coli biofilms in vitro. We hypothesized that MSC would reduce biofilm matrix and colony-forming units (CFU) compared to no treatment and that MSC combined with the antibiotic, amikacin sulfate, would reduce these components more than MSC or amikacin alone. MSC were isolated from 5 adult Thoroughbred horses in antibiotic-free medium. 24-hour S. aureus or E. coli biofilms were co-cultured in triplicate for 24 or 48 hours in a transwell plate system: untreated (negative) control, 30 μg/mL amikacin, 1 x 106 passage 3 MSC, and MSC with 30 μg/mL amikacin. Treated biofilms were photographed and biofilm area quantified digitally. Biomass was quantified via crystal violet staining, and CFU quantified following enzymatic digestion. Data were analyzed using mixed model ANOVA with Tukey post-hoc comparisons (p < 0.05). MSC significantly reduced S. aureus biofilms at both timepoints and E. coli biofilm area at 48 hours compared to untreated controls. MSC with amikacin significantly reduced S. aureus biofilms versus amikacin and E. coli biofilms versus MSC at 48 hours. MSC significantly reduced S. aureus biomass at both timepoints and reduced S. aureus CFU at 48 hours versus untreated controls. MSC with amikacin significantly reduced S. aureus biomass versus amikacin at 24 hours and S. aureus and E. coli CFU versus MSC at both timepoints. MSC primarily disrupted the biofilm matrix but performed differently on S. aureus versus E. coli. Evaluation of biofilm-MSC interactions, MSC dose, and treatment time are warranted prior to testing in vivo.

Simple and Cost-Effective Generation of 3D Cell Sheets and Spheroids Using Curvature-Controlled Paraffin Wax Substrates

The challenges associated with animal testing in pharmaceutical development have driven the search for alternative in vitro models that mimic human tissues more accurately. In this study, we present a simple and cost-effective method for generating 3D cell sheets and spheroids using curvature-controlled paraffin wax films, which are easily accessible laboratory materials that eliminate the need for extracellular matrix (ECM) components or thermo-responsive polymers. By adjusting the curvature of the paraffin wax film, we successfully generated human periodontal ligament fibroblast (HPdLF) cell sheets and bone marrow-derived mesenchymal stem cell (hBMSC) spheroids. Key parameters, such as cell density, substrate curvature, and incubation time, were identified as critical factors for optimizing the formation of these 3D structures. In addition, the use of quantum dots (QDs) for cell tracking enabled long-term visualization and distinction between different cell types within complex tissue-like structures. We further demonstrated that wrapping the hBMSC spheroids with HPdLF cell sheets partially replicated the connective tissue structure of the periodontal ligament surrounding the tooth root. This highlights the potential of this platform for the construction of more sophisticated tissue-mimicking assemblies. In conclusion, curvature-controlled paraffin wax films provide a versatile and practical approach for 3D cell cultures. This simplifies the generation of both cell sheets and spheroids, offering a promising tool for tissue engineering and regenerative medicine applications, where precise cell-to-cell interactions are essential.Graphical abstract

Polydeoxyribonucleotide ameliorates IL-1β-induced impairment of chondrogenic differentiation in human bone marrow-derived mesenchymal stem cells

Osteoarthritis (OA) is a degenerative disease of the joints, prevalent worldwide. Polydeoxyribonucleotide (PDRN) is used for treating knee OA. However, the role of PDRN in IL-1β-induced inflammatory responses in human bone marrow-derived mesenchymal stem cells (hBMSCs) remains unknown. Here, we investigated the role of PDRN in IL-1β-induced impairment of chondrogenic differentiation in hBMSCs. hBMSCs treated with PDRN showed a large micromass, enhanced safranin O and alcian blue staining intensity, and increased expression of chondrogenic genes in IL-1β-induced inflammatory responses, in addition to regulation of catabolic and anabolic genes. In addition, PDRN treatment suppressed the expression of inflammatory cytokines and mitigated IL-1β-induced apoptosis in hBMSCs. Mechanistically, PDRN treatment increased the formation of cyclic adenosine monophosphate (cAMP) and upregulated the phosphorylation of cAMP-dependent protein kinase A (PKA)/cAMP response element binding protein (CREB) through the adenosine A2A receptor in hBMSCs and thus blocked the nuclear factor kappa-light-chain-enhancer of activated B cell (NF-κB) signaling pathway. Thus, IL-1β-induced expression of inflammatory cytokines in hBMSCs was directly reduced by adenosine A2A receptor activation. Based on our results, we suggest that PDRN may be a promising MSC-based therapeutic agent for OA.

Evaluating the therapeutic potential of different sources of mesenchymal stem cells in acute respiratory distress syndrome

BackgroundMesenchymal stem/stromal cells (MSCs) have attracted interest as a potential therapy given their anti-inflammatory and immunomodulatory properties. However, clinical trials using MSCs for acute respiratory distress syndrome (ARDS) have produced mixed and inconclusive data. In previous work, we performed a “head-to-head” comparison between different sources of MSCs and showed that each source had a unique genomic and proteomic “signature”.MethodThis study investigated which sources of MSC: bone marrow derived-MSCs (BM-MSCs), adipose tissue derived-MSCs (AD-MSCs) and umbilical cord derived-MSCs (UC-MSCs) would be the optimal candidate to be used as a therapy in an LPS-induced mouse model of ARDS. Immune cells assessment, tissue transcriptomics, animal survival, and endothelial-epithelial barrier assessment were used to evaluate their effects.ResultsWhen comparing the three most commonly used MSC sources, we found that UC-MSCs exhibited greater efficacy compared to other MSCs in improving animal survival, mitigating epithelial/endothelial damage, decreasing lung inflammation via reducing neutrophil infiltration, T cell proliferation, and M1 polarization. Bulk RNA sequencing of lung tissue also showed that UC-MSCs have the capability to downregulate extracellular trap formation, by the downregulation of key genes like Elane and Padi4. Notably, treatment with UC-MSCs demonstrated a significant reduction in Fc-γ R mediated phagocytosis, which has been associated with monocyte pyroptosis and intense inflammation in the context of COVID-19.ConclusionOur findings suggest that UC-MSCs are an optimal source of MSC to treat acute inflammatory conditions in the lungs, such as ARDS.