The immunosuppressive properties of mesenchymal stem cells

Surface modification of decellularized kidney scaffold with chemokine and AKI-CKD cytokine juice to increase the recellularization efficiency of bio-engineered kidney

Chronic kidney disease (CKD) is a prevalent global health issue, primarily caused by glomerular dysfunction, diabetes, endovascular disorders, hypertensive nephrosclerosis, and other vascular diseases. Despite the increase in available organ sources, significant challenges remain in securing organ compatibility, prompting extensive research into creating a bio-artificial kidney free from immune rejection. In this study, a bio-engineered kidney was established using a stem cell chemoattractant within a bioreactor system; rBMSCs were used to recellularize the decellularized kidney scaffold coated with SDF-1α/AKI-CKD cytokine juice under mimic-hypoxic conditions as these chemokines and cytokines are crucial for the cell migration. LC-MS/MS proteomic analysis of the scaffold suggested that it contains various important proteins related to angiogenesis, cell migration, differentiation, etc. The in-silico binding simulation and Immunohistochemical (IHC) staining were utilized to detect the coated chemokines and cytokines. Cells were administered through both ureter and arterial routes of the kidney scaffold to differentiate into epithelial and endothelial cells. After 14 days of the recellularization process utilizing a mimic-hypoxia-induced bioreactor, the SDF-1α/AKI-CKD CJ-coated kidney scaffold exhibited high levels of cell attachment, migration, and proliferation in both the cortex and medulla. Additionally, the coating of the cytokines remarkably enhanced the expression of specific renal cell markers within the complex microfilter-like tubular structures. This study underscores a recellularization strategy that addresses the challenges associated with constructing bio-artificial kidneys and contributes to the growing field of bio-artificial organ research.

Mesenchymal Stem Cell Injections for the Treatment of Osteoarthritis: A Systematic Review of Clinical Trials

Objectives

Osteoarthritis is a prevalent degenerative disease that affects many people worldwide. The use of mesenchymal stem cells (MSCs) in the setting of osteoarthritis has been explored by many clinical trials in the literature. Exploring these clinical trials is important for assessing the benefit of this modality in the setting of osteoarthritis.

Methods

On November 9, 2022, a search was conducted on PubMed/MEDLINE databases to explore clinical trials involving MSC injections for osteoarthritis. Only articles that were clinical trials, explored the use of MSC injections in osteoarthritis, involved human subjects, and written in English language, were included. Relevant data was extracted from the included trials.

Results

A total of 43 trials were included (N=43). The knee was most the commonly explored joint (95.4%), and adipose tissue was the most commonly utilized MSC source (49%). All but one trial (97.7%) reported clinical improvement in the MSC group on follow up, and 33 trials (76.7%) reported better clinical outcomes in the MSC groups when compared to control groups. Twenty-three trials (53.5%) used imaging to evaluate outcomes following MSC injections, out of which twenty (46.5%) reported improvements in the affected joint. Similarly, four trials (9.3%) used second look arthroscopy, out of which three (7%) reported better outcomes on follow up.

Conclusion

While published trials show good therapeutic potential for MSC injections in the setting of osteoarthritis, several discrepancies render the efficiency and reliability of this modality equivocal. The adoption of standardized protocols, employment of comprehensive evaluation tools, and reporting negative results is essential in order to appropriately assess the utility of MSC injections for the treatment of osteoarthritis.

Potential therapeutic options for celiac Disease: An update on Current evidence from Gluten-Free diet to cell therapy

Celiac disease (CD) is a chronic autoimmune enteropathy and multifactorial disease caused by inappropriate immune responses to gluten in the small intestine. Weight loss, anemia, osteoporosis, arthritis, and hepatitis are among the extraintestinal manifestations of active CD. Currently, a strict lifelong gluten-free diet (GFD) is the only safe, effective, and available treatment. Despite the social burden, high expenses, and challenges of following a GFD, 2 to 5 percent of patients do not demonstrate clinical or pathophysiological improvement. Therefore, we need novel and alternative therapeutic approaches for patients. Innovative approaches encompass a broad spectrum of strategies, including enzymatic degradation of gluten, inhibition of intestinal permeability, modulation of the immune response, inhibition of the transglutaminase 2 (TG2) enzyme, blocking antigen presentation by HLA-DQ2/8, and induction of tolerance. Hence, this review is focused on comprehensive therapeutic strategies ranging from dietary approaches to novel methods such as antigen-based immunotherapy, cell and gene therapy, and the usage of nanoparticles for CD treatment.

Use of Biologics and Stem Cells in the Treatment of Other Inflammatory Diseases in the Horse

Mesenchymal stem cells (MSCs) are powerful immunomodulatory cells that act via multiple mechanisms to coordinate, inhibit, and control the cells of the immune system. MSCs act as rescuers for various damaged or degenerated cells of the body via (1) cytokines, growth factors, and signaling molecules; (2) extracellular vesicle (exosome) signaling; and (3) direct donation of mitochondria. Several studies evaluating the efficacy of MSCs have used MSCs grown using xenogeneic media, which may reduce or eliminate efficacy. Although more research is needed to optimize the anti-inflammatory potential of MSCs, there is ample evidence that MSC therapeutics are worthy of further development.

Mesenchymal Stromal Cell Therapy for Thoracic Surgeons: An Update

Stem cells are undifferentiated cells presenting extensive self-renewal features and the ability to differentiate "in vitro" and "in vivo" into a range of lineage cells, like chondrogenic, osteogenic and adipogenic lineages when cultured in specific inducing media. Two major domains of clinical applications of stem cells in thoracic surgery have been investigated: regenerative medicine, which is a section of translational research in tissue engineering focusing on the replacement, renewal or regeneration of cells, tissues and organs to re-establish damaged physiologic functions; drug loading and delivery, representing a new branch proposing stem cells as carriers to provide selected districts with anti-cancer agents for targeted treatments.

Exploring the future potential of mesenchymal stem/stromal cells and their derivatives to support assisted reproductive technology for female infertility applications

Women's infertility impacts the quality of life of both patients and couples and has multifaceted dimensions that increase the number of challenges associated with female infertility and how to face them. Female reproductive disorders, such as premature ovarian failure (POF), endometriosis, Asherman syndrome (AS), polycystic ovary syndrome (PCOS), and preeclampsia, can stimulate infertility. In the last decade, translational medicine has advanced, and scientists are focusing on infertility therapy with innovative attitudes. Recent investigations have suggested that stem cell treatments could be safe and effective. Stem cell therapy has established a novel method for treating women's infertility as part of a regeneration approach. The chief properties and potential of mesenchymal stem/stromal cells (MSCs) in the future of women's infertility should be considered by researchers. Due to their high abundance, great ability to self-renew, and high differentiation capacity, as well as less ethical concerns, MSC-based therapy has been found to be an effective alternative strategy to the previous methods for treating female infertility, such as intrauterine insemination, in vitro fertilization, medicines, and surgical procedures. These types of stem cells exert their beneficial role by releasing active mediators, promoting cell homing, and contributing to immune modulation. Here we first provide an overview of MSCs and their crucial roles in both biological and immunological processes. The next large chapter covers current preclinical and clinical studies on the application of MSCs to treat various female reproductive disorders. Finally, we deliberate on the extant challenges that hinder the application of MSCs in female infertility and suggest plausible measures to alleviate these impediments.

The Implications of Microglial Regulation in Neuroplasticity-Dependent Stroke Recovery

Stroke causes varying degrees of neurological deficits, leading to corresponding dysfunctions. There are different therapeutic principles for each stage of pathological development. Neuroprotection is the main treatment in the acute phase, and functional recovery becomes primary in the subacute and chronic phases. Neuroplasticity is considered the basis of functional restoration and neurological rehabilitation after stroke, including the remodeling of dendrites and dendritic spines, axonal sprouting, myelin regeneration, synapse shaping, and neurogenesis. Spatiotemporal development affects the spontaneous rewiring of neural circuits and brain networks. Microglia are resident immune cells in the brain that contribute to homeostasis under physiological conditions. Microglia are activated immediately after stroke, and phenotypic polarization changes and phagocytic function are crucial for regulating focal and global brain inflammation and neurological recovery. We have previously shown that the development of neuroplasticity is spatiotemporally consistent with microglial activation, suggesting that microglia may have a profound impact on neuroplasticity after stroke and may be a key therapeutic target for post-stroke rehabilitation. In this review, we explore the impact of neuroplasticity on post-stroke restoration as well as the functions and mechanisms of microglial activation, polarization, and phagocytosis. This is followed by a summary of microglia-targeted rehabilitative interventions that influence neuroplasticity and promote stroke recovery.

Evaluation of the relationship between mesenchymal stem cells and immune system in vitro conditions

BACKGROUND

Mesenchymal stem cells (MSCs), are a novel therapeutic option as the most common cell source, play an important role in the immunomodulation. In this study, it was aimed to determine the effect of MSCs on cytokines secreted by the immune system cells.

METHODS

Intracellular cytokine levels (Interleukin-4 (IL-4), Interferon-γ (IFN-γ), and Interleukin-17 (IL-17)) detected by flow cytometry before and after co-culture between peripheral blood mononuclear cells (PBMCs) and MCSs. At the same time, supernatant cytokine levels were measured using the ELISA.

RESULTS

In our study, MSCs were isolated from cord blood (CB) and Wharton's Jelly (WJ), and their surface markers (CD44 (100%), CD73 (99.6%), CD90 (100%), CD105 (88%)) shown by flow cytometry method. Both CB-MSCs and WJ-MSCs were used in co-culture MSC/PBMC ratios of 1/5 and 1/10, incubation times of 24 h and 72 h. In the present study, when we compared co-cultures of CB-MSC or WJ-MSC with PBMCs, intracellular levels of cytokines IFN-γ, IL-17 (pro-inflamatory) and IL-4 (anti-inflamatory) were increased, and supernatant levels were decreased significantly (p < 0.05). The level of transforming growth factor beta (TGF-β) (anti-inflamatory) was significantly decreased for both CB-MSC and WJ-MSC in supernatant (p < 0.05).

CONCLUSIONS

It was investigated pro-inflammatory and anti-inflammatory effects of CB-MSCs and WJ-MSCs on PBMCs with the obtained results. According to the results, MSCs demonstrated different immunologic effects after the incubation time and ratios. For further studies, it should be known between interaction of MSCs and immune system.

Model to Inhibit Contraction in Third-Degree Burns Employing Split-Thickness Skin Graft and Administered Bone Marrow-Derived Stem Cells

Third-degree burns typically result in pronounced scarring and contraction in superficial and deep tissues. Established techniques such as debridement and grafting provide benefit in the acute phase of burn therapy, nevertheless, scar and contraction remain a challenge in deep burns management. Our ambition is to evaluate the effectiveness of novel cell-based therapies, which can be implemented into the standard of care debridement and grafting procedures. Twenty-seven third-degree burn wounds were created on the dorsal area of Red Duroc pig. After 72 h, burns are surgically debrided using a Weck knife. Split-thickness skin grafts (STSGs) were then taken after debridement and placed on burn scars combined with bone marrow stem cells (BM-MSCs). Biopsy samples were taken on days 17, 21, and 45 posttreatment for evaluation. Histological analysis revealed that untreated control scars at 17 days are more raised than burns treated with STSGs alone and/or STSGs with BM-MSCs. Wounds treated with skin grafts plus BM-MSCs appeared thinner and longer, indicative of reduced contraction. qPCR revealed some elevation of α-SMA expression at day 21 and Collagen Iα2 in cells derived from wounds treated with skin grafts alone compared to wounds treated with STSGs + BM-MSCs. We observed a reduction level of TGFβ-1 expression at days 17, 21, and 45 in cells derived from wounds treated compared to controls. These results, where the combined use of stem cells and skin grafts stimulate healing and reduce contraction following third-degree burn injury, have a potential as a novel therapy in the clinic.

Scaffold Guided Bone Regeneration for the Treatment of Large Segmental Defects in Long Bones

Bone generally displays a high intrinsic capacity to regenerate. Nonetheless, large osseous defects sometimes fail to heal. The treatment of such large segmental defects still represents a considerable clinical challenge. The regeneration of large bone defects often proves difficult, since it relies on the formation of large amounts of bone within an environment impedimental to osteogenesis, characterized by soft tissue damage and hampered vascularization. Consequently, research efforts have concentrated on tissue engineering and regenerative medical strategies to resolve this multifaceted challenge. In this review, we summarize, critically evaluate, and discuss present approaches in light of their clinical relevance; we also present future advanced techniques for bone tissue engineering, outlining the steps to realize for their translation from bench to bedside. The discussion includes the physiology of bone healing, requirements and properties of natural and synthetic biomaterials for bone reconstruction, their use in conjunction with cellular components and suitable growth factors, and strategies to improve vascularization and the translation of these regenerative concepts to in vivo applications. We conclude that the ideal all-purpose material for scaffold-guided bone regeneration is currently not available. It seems that a variety of different solutions will be employed, according to the clinical treatment necessary.

Connection between Mesenchymal Stem Cells Therapy and Osteoclasts in Osteoarthritis

The use of mesenchymal stem cells constitutes a promising therapeutic approach, as it has shown beneficial effects in different pathologies. Numerous in vitro, pre-clinical, and, to a lesser extent, clinical trials have been published for osteoarthritis. Osteoarthritis is a type of arthritis that affects diarthritic joints in which the most common and studied effect is cartilage degradation. Nowadays, it is known that osteoarthritis is a disease with a very powerful inflammatory component that affects the subchondral bone and the rest of the tissues that make up the joint. This inflammatory component may induce the differentiation of osteoclasts, the bone-resorbing cells. Subchondral bone degradation has been suggested as a key process in the pathogenesis of osteoarthritis. However, very few published studies directly focus on the activity of mesenchymal stem cells on osteoclasts, contrary to what happens with other cell types of the joint, such as chondrocytes, synoviocytes, and osteoblasts. In this review, we try to gather the published bibliography in relation to the effects of mesenchymal stem cells on osteoclastogenesis. Although we find promising results, we point out the need for further studies that can support mesenchymal stem cells as a therapeutic tool for osteoclasts and their consequences on the osteoarthritic joint.

Menstrual blood-derived mesenchymal stromal cells efficiently ameliorate experimental autoimmune encephalomyelitis by inhibiting T cell activation in mice

Background

Immunosuppressive properties grant mesenchymal stromal cells (MSCs) promising potential for treating autoimmune diseases. As autologous MSCs suffer from limited availability, the readily available allogeneic MSCs isolated from menstrual blood (MB-MSCs) donated by young, healthy individuals offer great potential. Here, we evaluate the therapeutic potential of MB-MSCs as ready-to-use allo-MSCs in multiple sclerosis, an autoimmune disease developed by the activation of myelin sheath-reactive Th1 and Th17 cells, by application in its animal model experimental autoimmune encephalomyelitis (EAE).

Methods

We assessed the therapeutic effect of MB-MSCs transplanted via either intravenous (i.v.) or intraperitoneal (i.p.) route in EAE in comparison with umbilical cord-derived MSCs (UC-MSCs). We used histology to assess myelin sheath integrity and infiltrated immune cells in CNS and flow cytometry to evaluate EAE-associated inflammatory T cells and antigen-presenting cells in lymphoid organs.

Results

We observed disease-ameliorating effects of MB-MSCs when transplanted at various stages of EAE (day − 1, 6, 10, and 19), via either i.v. or i.p. route, with a potency comparable to UC-MSCs. We observed reduced Th1 and Th17 cell responses in mice that had received MB-MSCs via either i.v. or i.p. injection. The repressed Th1 and Th17 cell responses were associated with a reduced frequency of plasmacytoid dendritic cells (pDCs) and a suppressed co-stimulatory capacity of pDCs, cDCs, and B cells.

Conclusions

Our data demonstrate that the readily available MB-MSCs significantly reduced the disease severity of EAE upon transplantation. Thus, they have the potential to be developed as ready-to-use allo-MSCs in MS-related inflammation.

Graphical abstract

Supplementary Information

The online version contains supplementary material available at 10.1186/s13287-022-02838-8.

Alloreactivity of Allogeneic Mesenchymal Stem/Stromal Cells and Other Cellular Therapies: A Concise Review

Cellular therapies, deemed live medicine, have brought a wave of new generation biological therapies to treat previously untreatable diseases such as cancers and degenerative diseases like osteoarthritis. These cellular therapies have gained significant recognition in clinical research. The area has been further strengthened with the approval of Chimeric Antigen Receptor added on T cells (CAR-T) therapies by the regulatory authorities USA's Food and Drugs Administration (FDA), European Medical Agency (EMA), the Australian Therapeutic Goods Administration (TGA), and in many countries in 2017 to treat hematological cancers. Another milestone was achieved when allogeneic Mesenchymal Stem Cell- (MSC-) based therapy was approved by the EMA to treat Chrohn's disease in 2018. Allogeneic donor-derived MSC therapies in particular hold great promise and real hope because of their ‘off-the shelf' availability and accessibility for patients in need of urgent treatment. So far, thousands of clinical trials have explored the safety and efficacy of both autologous and allogeneic cell therapies, deeming them safe, however with varying degrees of efficacy. In the current pandemic, clinical trials have begun in many parts of the world to treat severe cases of COVID with MSCs. However, the risk of tissue rejection and the development of undesirable effects due to alloreactivity of allogeneic cells are currently not adequately addressed. Therefore, this warrants careful investigation and detailed reporting of such events by clinical researchers. This review aims at discussing the current landscape of approved allogeneic MSCs along with a few other cellular therapies. We explore any possible reactivity reported to inform the readers of any safety concern and on the efficacy of such therapies.

Inflammation Regulates Haematopoietic Stem Cells and Their Niche

Haematopoietic stem cells (HSCs) reside in the bone marrow and are supported by the specialised microenvironment, a niche to maintain HSC quiescence. To deal with haematopoietic equilibrium disrupted during inflammation, HSCs are activated from quiescence directly and indirectly to generate more mature immune cells, especially the myeloid lineage cells. In the process of proliferation and differentiation, HSCs gradually lose their self-renewal potential. The extensive inflammation might cause HSC exhaustion/senescence and malignant transformation. Here, we summarise the current understanding of how HSC functions are maintained, damaged, or exhausted during acute, prolonged, and pathological inflammatory conditions. We also highlight the inflammation-altered HSC niche and its impact on escalating the insults on HSCs.

22-kD growth hormone-induced nuclear GHR/STAT5/CyclinD1 signaling pathway plays an important role in promoting mesenchymal stem cell proliferation

Growth hormone (GH) exhibited the important biological activities in the mesenchymal stem cell (MSCs). However, the cellular behavior and properties of GH/GHR in MSCs remain unclear. A series of experiments (such as confocal laser scanning microscope [CLSM] and Western-blot) were performed to systematically investigate the cellular behavior of GH/GHR in MSCs, and the results showed that GH/GHR not only internalized into the cytoplasm, but also transported into the cell nuclei of MSCs. Furthermore, we studied the molecular mechanism by which GH/GHR internalized into cell, and the results indicated that clathrin plays more important role in the process of GHR internalization. More importantly, it can be found that nuclear-targeted GHR has the important biological functions in MSCs, which could promote MSCs proliferation. We further revealed the molecular mechanism by which nuclear-localized GHR regulates MSCs proliferation, and found that nuclear-targeted GHR enhanced the phosphorylation of STAT5, and the activated STAT5 initiates the transcription of CyclinD1, after which, the complex of CyclinD1 and CDK4 further phosphorylates Rb, and the activated Rb releases E2F1, the released E2F1 ultimately realizes the biological function of GH promoting cell proliferation. In short, in the current study，we used MSCs as a model to study the cellular behavior and properties of GH/GHR, and found that GH/GHR can internalize into cell cytoplasm and transport into the cell nuclei. Further work showed that nuclear GHR could drive cell proliferation via GHR/STAT5/CyclinD1 signaling pathway. The current research has laid an important foundation for further study on the regulatory effect of GH on MSCs.

Management of Chronic Graft-vs.-Host Disease in Children and Adolescents With ALL: Present Status and Model for a Personalised Management Plan

Herein we review current practice regarding the management of chronic graft-vs.-host disease (cGvHD) in paediatric patients after allogeneic haematopoietic stem cell transplantation (HSCT) for acute lymphoblastic leukaemia (ALL). Topics covered include: (i) the epidemiology of cGvHD; (ii) an overview of advances in our understanding cGvHD pathogenesis; (iii) current knowledge regarding risk factors for cGvHD and prevention strategies complemented by biomarkers; (iii) the paediatric aspects of the 2014 National Institutes for Health-defined diagnosis and grading of cGvHD; and (iv) current options for cGvHD treatment. We cover topical therapy and newly approved tyrosine kinase inhibitors, emphasising the use of immunomodulatory approaches in the context of the delicate counterbalance between immunosuppression and immune reconstitution as well as risks of relapse and infectious complications. We examine real-world approaches of response assessment and tapering schedules of treatment. Furthermore, we report on the optimal timepoints for therapeutic interventions and changes in relation to immune reconstitution and risk of relapse/infection. Additionally, we review the different options for anti-infectious prophylaxis. Finally, we put forth a theory of a holistic view of paediatric cGvHD and its associated manifestations and propose a checklist for individualised risk evaluation with aggregated considerations including site-specific cGvHD evaluation with attention to each individual's GvHD history, previous medical history, comorbidities, and personal tolerance and psychosocial circumstances. To complement this checklist, we present a treatment algorithm using representative patients to inform the personalised management plans for patients with cGvHD after HSCT for ALL who are at high risk of relapse.

OUP accepted manuscript

Graft versus host disease (GVHD) is a severe complication after allogenic hematopoietic cell transplantation (HSCT). Several clinical trials have reported the use of mesenchymal stromal cells (MSCs) for the treatment of GVHD. In March 2008, the Andalusian Health Care System launched a compassionate use program to treat steroid-resistant GVHD with MSC. Clinical-grade MSC were obtained under GMP conditions. MSC therapy was administered intravenously in four separate doses of 1 × 10⁶ cells/kg. Sixty-two patients, 45 males (7 children) and 17 females (2 children), received the treatment. Patients had a median age of 39 years (range: 7–66) at the time of the allogenic HSCT. The overall response was achieved in 58.7% of patients with acute (a)GVHD. Two years’ survival for aGVHD responders was 51.85%. The overall response for patients with chronic (c)GVHD was 65.50% and the 2-year survival rate for responders was 70%. Age at the time of HSCT was the only predictor found to be inversely correlated with survival in aGVHD. Regarding safety, four adverse events were reported, all recovered without sequelae. Thus, analysis of this compassionate use experience shows MSC to be an effective and safe therapeutic option for treating refractory GVHD, resulting in a significant proportion of patients responding to the therapy.

Secretome of Mesenchymal Bone Marrow Stem Cells: Is It Immunosuppressive or Proinflammatory?

Mesenchymal stem cells (MSC) are characterized by tolerogenic potential and therefore, are used in the treatment of autoimmune diseases such as graft-versus-host disease (GVHD) reactions after allogeneic hematopoietic cell transplantation to improve the transplant functions, as well as for the therapy and prevention of cytokine storm in COVID-19 patients and some other conditions. However, MSC can exhibit proinflammatory activity, which causes risks for their clinical use. We studied the cytokine profile of bone marrow MSC culture and demonstrate intensive production of IL-6, IL-8, and chemokine MCP-1, which participate in the pathogenesis of cytokine storm and GVHD. At the same time, no anti-inflammatory IL-4 and IL-10 were detected. To reduce the risks of MSC application in the GVHD therapeutic protocols, further studies of the conditions promoting generation of MSC with tolerogenic potential and approved clinical standards of MSC use are required.

In vitro evaluation of periapical lesion-derived stem cells for dental pulp tissue engineering

Dental pulp tissue engineering is a promising alternative treatment for pulpitis and periapical periodontitis, and dental pulp stem cells (DPSCs) are considered to be the gold standard for dental seed cell research. Periapical lesions harbor mesenchymal stem cells with the capacity for self-renewal and multilineage differentiation. However, it remains unknown whether these periapical lesion-derived stem cells (PLDSCs) are suitable for dental pulp tissue engineering. To investigate this possibility, PLDSCs and DPSCs were isolated using the tissue outgrowth method and cultured under identical conditions. We then performed in vitro experiments to investigate their biological characteristics. Our results indicate that PLDSCs proliferate actively in vitro and exhibit similar morphology, immunophenotype and multilineage differentiation ability as DPSCs. Simultaneously, PLDSCs exhibit stronger migrative ability and express more vascular endothelial growth factor and glial cell line-derived neurotrophic factor than DPSCs, and PLDSC-derived conditioned medium was more effective in tube formation assay. The mRNA expression levels of immunomodulatory genes HLA-G, IDO and ICAM-1 were also higher in PLDSCs. However, regarding osteo/odontogenic differentiation, PLDSCs showed weaker alkaline phosphatase staining and lower calcified nodule formation compared to DPSCs, as well as lower expression of ALP, RUNX2 and DSPP, as confirmed by a quantitative RT-PCR. The osteo/odontogenic protein expression levels of DSPP, RUNX2, DMP1 and SP7 were also higher in DPSCs. The present study demonstrates that PLDSCs demonstrate potential use as seed cells for dental pulp regeneration, especially for achieving enhanced neurovascularization.

Human Wharton's Jelly-Derived Mesenchymal Stromal Cells Primed by Tumor Necrosis Factor-α and Interferon-γ Modulate the Innate and Adaptive Immune Cells of Type 1 Diabetic Patients

The unique immunomodulation and immunosuppressive potential of Wharton’s jelly-derived mesenchymal stromal cells (WJ-MSCs) make them a promising therapeutic approach for autoimmune diseases including type 1 diabetes (T1D). The immunomodulatory effect of MSCs is exerted either by cell-cell contact or by secretome secretion. Cell-cell contact is a critical mechanism by which MSCs regulate immune-responses and generate immune regulatory cells such as tolerogenic dendritic cells (tolDCs) and regulatory T cell (Tregs). In this study, we primed WJ-MSCs with TNF-α and IFN-γ and investigated the immunomodulatory properties of primed WJ-MSCs on mature dendritic cells (mDCs) and activated T cells differentiated from mononuclear cells (MNCs) of T1D patient’s. Our findings revealed that primed WJ-MSCs impaired the antigen-mediated immunity, upregulated immune-tolerance genes and downregulated immune-response genes. We also found an increase in the production of anti-inflammatory cytokines and suppression of the production of pro-inflammatory cytokines. Significant upregulation of FOXP3, IL10 and TGFB1 augmented an immunosuppressive effect on adaptive T cell immunity which represented a strong evidence in support of the formation of Tregs. Furthermore, upregulation of many critical genes involved in the immune-tolerance mechanism (IDO1 and PTGES2/PTGS) was detected. Interestingly, upregulation of ENTPD1/NT5E genes express a strong evidence to switch immunostimulatory response toward immunoregulatory response. We conclude that WJ-MSCs primed by TNF-α and IFN-γ may represent a promising tool to treat the autoimmune disorders and can provide a new evidence to consider MSCs- based therapeutic approach for the treatment of TID.

The inflammatory signalling mediator TAK1 mediates lymphocyte recruitment to lipopolysaccharide-activated murine mesenchymal stem cells through interleukin-6

As a response to pro-inflammatory signals mesenchymal stem cells (MSCs) secrete agents and factors leading to lymphocyte recruitment, counteracting inflammation, and stimulating immunosuppression. On a molecular level, the signalling mediator TGF-β-activated kinase 1 (TAK1) is activated by many pro-inflammatory signals, plays a critical role in inflammation and regulates innate and adaptive immune responses as well. While the role of TAK1 as a signalling factor promoting inflammation is well documented, we also considered a role for TAK1 in anti-inflammatory actions exerted by activated MSCs. We, therefore, investigated the capacity of lipopolysaccharide (LPS)-treated murine MSCs with lentivirally modulated TAK1 expression levels to recruit lymphocytes. TAK1 downregulated by lentiviral vectors expressing TAK1 shRNA in murine MSCs interfered with the capacity of murine MSCs to chemoattract lymphocytes, indeed. Analysing a pool of 84 secreted factors we found that among 26 secreted cytokines/factors TAK1 regulated expression of one cytokine in LPS-activated murine MSCs in particular: interleukin-6 (IL-6). IL-6 in LPS-treated MSCs was responsible for lymphocyte recruitment as substantiated by neutralizing antibodies. Our studies, therefore, suggest that in LPS-treated murine MSCs the inflammatory signalling mediator TAK1 may exert anti-inflammatory properties via IL-6.

Therapeutic Implications of Mesenchymal Stromal Cells and Their Extracellular Vesicles in Autoimmune Diseases: From Biology to Clinical Applications

Mesenchymal stromal cells (MSCs) are perivascular multipotent stem cells originally identified in the bone marrow (BM) stroma and subsequently in virtually all vascularized tissues. Because of their ability to differentiate into various mesodermal lineages, their trophic properties, homing capacity, and immunomodulatory functions, MSCs have emerged as attractive candidates in tissue repair and treatment of autoimmune disorders. Accumulating evidence suggests that the beneficial effects of MSCs may be primarily mediated via a number of paracrine-acting soluble factors and extracellular vesicles (EVs). EVs are membrane-coated vesicles that are increasingly being acknowledged as playing a key role in intercellular communication via their capacity to carry and deliver their cargo, consisting of proteins, nucleic acids, and lipids to recipient cells. MSC-EVs recapitulate the functions of the cells they originate, including immunoregulatory effects but do not seem to be associated with the limitations and concerns of cell-based therapies, thereby emerging as an appealing alternative therapeutic option in immune-mediated disorders. In the present review, the biology of MSCs will be outlined and an overview of their immunomodulatory functions will be provided. In addition, current knowledge on the features of MSC-EVs and their immunoregulatory potential will be summarized. Finally, therapeutic applications of MSCs and MSC-EVs in autoimmune disorders will be discussed.

Efficacy and safety of mesenchymal stem cell injections for patients with osteoarthritis: a meta-analysis and review of RCTs

INTRODUCTION

Osteoarthritis (OA), which has a high incidence in the elderly, brings a huge economic burden to society. MSCs (Mesenchymal Stem Cells) have shown great multidirectional differentiation potential which are expected to treat OA, and numerous clinical trials have been conducted. However, the efficacy and safety of the MSCs still need to be further integrated and analyzed.

MATERIALS AND METHODS

We searched several databases (PubMed, EMBASE, Scopus, Web of Science, Cochrane Library, Ovid, and ScienceDirect) for assessing eligible trials that randomized controlled trials, hyaluronic acid as control, and MSCs injection to treat OA. Vitro studies and animal studies were excluded. Search terms were: "cartilage," "clinical trial," "mesenchymal," "stromal" and "stem cell", "osteoarthritis". The preliminary guidelines and study protocol were published online at PROSPERO.

RESULTS

Many assessment scales could not be improved significantly after 6 months. However, most of the scales were significantly improved after 12 months, indicating that compared with hyaluronic acid, stem cells could relieve OA symptoms significantly. No serious adverse effect was found.

CONCLUSION

There are significant therapeutic effects on joint function, symptoms, and no permanent adverse effect has been found after stem cell treatment. It is promising to apply intro-articular injection of stem cells for OA to clinical application. More researches are needed to supplement present deficiencies.

Novel cell sources for bone regeneration

A plethora of both acute and chronic conditions, including traumatic, degenerative, malignant, or congenital disorders, commonly induce bone disorders often associated with severe persisting pain and limited mobility. Over 1 million surgical procedures involving bone excision, bone grafting, and fracture repair are performed each year in the U.S. alone, resulting in immense levels of public health challenges and corresponding financial burdens. Unfortunately, the innate self-healing capacity of bone is often inadequate for larger defects over a critical size. Moreover, as direct transplantation of committed osteoblasts is hindered by deficient cell availability, limited cell spreading, and poor survivability, an urgent need for novel cell sources for bone regeneration is concurrent. Thanks to the development in stem cell biology and cell reprogramming technology, many multipotent and pluripotent cells that manifest promising osteogenic potential are considered the regenerative remedy for bone defects. Considering these cells' investigation is still in its relative infancy, each of them offers their own particular challenges that must be conquered before the large-scale clinical application.

Recent Updates of Diagnosis, Pathophysiology, and Treatment on Osteoarthritis of the Knee

Osteoarthritis (OA) is a degenerative and chronic joint disease characterized by clinical symptoms and distortion of joint tissues. It primarily damages joint cartilage, causing pain, swelling, and stiffness around the joint. It is the major cause of disability and pain. The prevalence of OA is expected to increase gradually with the aging population and increasing prevalence of obesity. Many potential therapeutic advances have been made in recent years due to the improved understanding of the underlying mechanisms, diagnosis, and management of OA. Embryonic stem cells and induced pluripotent stem cells differentiate into chondrocytes or mesenchymal stem cells (MSCs) and can be used as a source of injectable treatments in the OA joint cavity. MSCs are known to be the most studied cell therapy products in cell-based OA therapy owing to their ability to differentiate into chondrocytes and their immunomodulatory properties. They have the potential to improve cartilage recovery and ultimately restore healthy joints. However, despite currently available therapies and advances in research, unfulfilled medical needs persist for OA treatment. In this review, we focused on the contents of non-cellular and cellular therapies for OA, and briefly summarized the results of clinical trials for cell-based OA therapy to lay a solid application basis for clinical research.

Multipotent Mesenchymal Stromal Cells in Rheumatoid Arthritis and Systemic Lupus Erythematosus; From a Leading Role in Pathogenesis to Potential Therapeutic Saviors?

The pathogenesis of the autoimmune rheumatological diseases including rheumatoid arthritis (RA) and systemic lupus erythematosus (SLE) is complex with the involvement of several immune cell populations spanning both innate and adaptive immunity including different T-lymphocyte subsets and monocyte/macrophage lineage cells. Despite therapeutic advances in RA and SLE, some patients have persistent and stubbornly refractory disease. Herein, we discuss stromal cells' dual role, including multipotent mesenchymal stromal cells (MSCs) also used to be known as mesenchymal stem cells as potential protagonists in RA and SLE pathology and as potential therapeutic vehicles. Joint MSCs from different niches may exhibit prominent pro-inflammatory effects in experimental RA models directly contributing to cartilage damage. These stromal cells may also be key regulators of the immune system in SLE. Despite these pro-inflammatory roles, MSCs may be immunomodulatory and have potential therapeutic value to modulate immune responses favorably in these autoimmune conditions. In this review, the complex role and interactions between MSCs and the haematopoietically derived immune cells in RA and SLE are discussed. The harnessing of MSC immunomodulatory effects by contact-dependent and independent mechanisms, including MSC secretome and extracellular vesicles, is discussed in relation to RA and SLE considering the stromal immune microenvironment in the diseased joints. Data from translational studies employing MSC infusion therapy against inflammation in other settings are contextualized relative to the rheumatological setting. Although safety and proof of concept studies exist in RA and SLE supporting experimental and laboratory data, robust phase 3 clinical trial data in therapy-resistant RA and SLE is still lacking.

Extracellular Vesicles in Musculoskeletal Pathologies and Regeneration

The incidence of musculoskeletal diseases is steadily increasing with aging of the population. In the past years, extracellular vesicles (EVs) have gained attention in musculoskeletal research. EVs have been associated with various musculoskeletal pathologies as well as suggested as treatment option. EVs play a pivotal role in communication between cells and their environment. Thereby, the EV cargo is highly dependent on their cellular origin. In this review, we summarize putative mechanisms by which EVs can contribute to musculoskeletal tissue homeostasis, regeneration and disease, in particular matrix remodeling and mineralization, pro-angiogenic effects and immunomodulatory activities. Mesenchymal stromal cells (MSCs) present the most frequently used cell source for EV generation for musculoskeletal applications, and herein we discuss how the MSC phenotype can influence the cargo and thus the regenerative potential of EVs. Induced pluripotent stem cell-derived mesenchymal progenitor cells (iMPs) may overcome current limitations of MSCs, and iMP-derived EVs are discussed as an alternative strategy. In the last part of the article, we focus on therapeutic applications of EVs and discuss both practical considerations for EV production and the current state of EV-based therapies.

Rejuvenated ageing mesenchymal stem cells by stepwise preconditioning ameliorates surgery-induced osteoarthritis in rabbits

AIMS

Ageing-related incompetence becomes a major hurdle for the clinical translation of adult stem cells in the treatment of osteoarthritis (OA). This study aims to investigate the effect of stepwise preconditioning on cellular behaviours in human mesenchymal stem cells (hMSCs) from ageing patients, and to verify their therapeutic effect in an OA animal model.

METHODS

Mesenchymal stem cells (MSCs) were isolated from ageing patients and preconditioned with chondrogenic differentiation medium, followed by normal growth medium. Cellular assays including Bromodeoxyuridine / 5-bromo-2'-deoxyuridine (BrdU), quantitative polymerase chain reaction (q-PCR), β-Gal, Rosette forming, and histological staining were compared in the manipulated human mesenchymal stem cells (hM-MSCs) and their controls. The anterior cruciate ligament transection (ACLT) rabbit models were locally injected with two millions, four millions, or eight millions of hM-MSCs or phosphate-buffered saline (PBS). Osteoarthritis Research Society International (OARSI) scoring was performed to measure the pathological changes in the affected joints after staining. Micro-CT analysis was conducted to determine the microstructural changes in subchondral bone.

RESULTS

Stepwise preconditioning approach significantly enhanced the proliferation and chondrogenic potential of ageing hMSCs at early passage. Interestingly, remarkably lower immunogenicity and senescence was also found in hM-MSCs. Data from animal studies showed cartilage damage was retarded and subchondral bone remodelling was prevented by the treatment of preconditioned MSCs. The therapeutic effect depended on the number of cells applied to animals, with the best effect observed when treated with eight millions of hM-MSCs.

CONCLUSION

This study demonstrated a reliable and feasible stepwise preconditioning strategy to improve the safety and efficacy of ageing MSCs for the prevention of OA development. Cite this article: Bone Joint Res 2021;10(1):10-21.

Preterm Brain Injury, Antenatal Triggers, and Therapeutics: Timing Is Key

With a worldwide incidence of 15 million cases, preterm birth is a major contributor to neonatal mortality and morbidity, and concomitant social and economic burden Preterm infants are predisposed to life-long neurological disorders due to the immaturity of the brain. The risks are inversely proportional to maturity at birth. In the majority of extremely preterm infants (<28 weeks' gestation), perinatal brain injury is associated with exposure to multiple inflammatory perinatal triggers that include antenatal infection (i.e., chorioamnionitis), hypoxia-ischemia, and various postnatal injurious triggers (i.e., oxidative stress, sepsis, mechanical ventilation, hemodynamic instability). These perinatal insults cause a self-perpetuating cascade of peripheral and cerebral inflammation that plays a critical role in the etiology of diffuse white and grey matter injuries that underlies a spectrum of connectivity deficits in survivors from extremely preterm birth. This review focuses on chorioamnionitis and hypoxia-ischemia, which are two important antenatal risk factors for preterm brain injury, and highlights the latest insights on its pathophysiology, potential treatment, and future perspectives to narrow the translational gap between preclinical research and clinical applications.

Three-dimensional culture of dental pulp pluripotent-like stem cells (DPPSCs) enhances Nanog expression and provides a serum-free condition for exosome isolation

Stem cell-derived exosomes have been identified as novel cell-free therapeutics for regenerative medicine. Three-dimensional (3D) culture of stem cells were reported to improve their "stemness" and therapeutic efficacy. This work focused on establishing serum-free 3D culture of dental pulp pluripotent-like stem cells (DPPSCs)-a newly characterized pluripotent-like stem cell for exosome production. DPPSCs were expanded in regular 2D culture in human serum-supplemented (HS)-medium and transferred to a micropatterned culture plate for 3D culture in HS-medium (default) and medium supplemented with KnockOut™ serum replacement (KO-medium). Bright-field microscopy observation throughout the culture period (24 days) revealed that DPPSCs in KO-medium formed spheroids of similar morphology and size to that in HS-medium. qRT-PCR analysis showed similar Oct4A gene expression in DPPSC spheroids in both HS-medium and KO-medium, but Nanog expression significantly increased in the latter. Vesicles isolated from DPPSC spheroids in KO-medium in the first 12 days of culture showed sizes that fall within the exosomal size range by nanoparticle tracking analysis (NTA) and express the canonical exosomal markers. It is concluded that 3D culture of DPPSCs in KO-medium provided an optimal serum-free condition for successful isolation of DPPSC-derived exosomes for subsequent applications in regenerative medicine.

Persistence of Drug-Resistant Leukemic Stem Cells and Impaired NK Cell Immunity in CML Patients Depend on MIR300 Antiproliferative and PP2A-Activating Functions

Persistence of drug-resistant quiescent leukemic stem cells (LSC) and impaired natural killer (NK) cell immune response account for relapse of chronic myelogenous leukemia (CML). Inactivation of protein phosphatase 2A (PP2A) is essential for CML-quiescent LSC survival and NK cell antitumor activity. Here we show that MIR300 has antiproliferative and PP2A-activating functions that are dose dependently differentially induced by CCND2/CDK6 and SET inhibition, respectively. MIR300 is upregulated in CML LSCs and NK cells by bone marrow microenvironment (BMM) signals to induce quiescence and impair immune response, respectively. Conversely, BCR-ABL1 downregulates MIR300 in CML progenitors to prevent growth arrest and PP2A-mediated apoptosis. Quiescent LSCs escape apoptosis by upregulating TUG1 long noncoding RNA that uncouples and limits MIR300 function to cytostasis. Genetic and pharmacologic MIR300 modulation and/or PP2A-activating drug treatment restore NK cell activity, inhibit BMM-induced growth arrest, and selectively trigger LSC apoptosis in vitro and in patient-derived xenografts; hence, the importance of MIR300 and PP2A activity for CML development and therapy.

Direct Conjugation of Retinoic Acid with Gold Nanoparticles to Improve Neural Differentiation of Human Adipose Stem Cells

Gold nanoparticles (AuNPs) have been proposed as useful medical carriers in the field of regenerative medicine. This study aimed to assess the direct conjugation ability of retinoic acid (RA) with AuNPs and to develop a strategy to differentiate the human adipose-derived stromal/stem cells (hADSCs) into neurons using AuNPs-RA. The physical properties of this nanocarrier were characterized using FT-IR, TEM, and FE-SEM. Moreover, the efficiency of RA conjugation on AuNPs was determined at 99% using UV-Vis spectroscopy. According to the MTT assay, an RA concentration of 66 μM caused a 50% inhibition of cell viability and AuNPs were not cytotoxic in concentrations below 5 μg/ml. Real-time PCR and immunocytochemistry proved that AuNPs-RA is able to increase the expression of neuronal marker genes and the number of neuronal protein (GFAP and MAP2)-positive cells, 14 days post-induction of hADSCs. Taken together, these results confirmed that the AuNPs-RA promote the neuronal differentiation of hADSCs.

Emerging Therapeutic Potential of Mesenchymal Stem/Stromal Cells in Preeclampsia

PURPOSE OF REVIEW

Preeclampsia is a dangerous pregnancy condition affecting both the mother and offspring. It is a multifactorial disease with poorly understood pathogenesis, lacking effective treatments. Maternal immune response, inflammation and oxidative stress leading to endothelial dysfunction are the most prominent pathogenic processes implicated in preeclampsia development. Here, we give a detailed overview of the therapeutic applications and mechanisms of mesenchymal stem/stromal cells (MSCs) as a potential new treatment for preeclampsia.

RECENT FINDINGS

MSCs have gained growing attention due to low immunogenicity, easy cultivation and expansion in vitro. Accumulating evidence now suggests that MSCs act primarily through their secretomes facilitating paracrine signalling that leads to potent immunomodulatory, pro-angiogenic and regenerative therapeutic effects. MSCs have been studied in different animal models of preeclampsia demonstrating promising result, which support further investigations into the therapeutic effects and mechanisms of MSC-based therapies in preeclampsia, steering these therapies into clinical trials.

Mesenchymal Stem Cells Beyond Regenerative Medicine

Mesenchymal stem cells (MSCs) are competent suitors of cellular therapy due to their therapeutic impact on tissue degeneration and immune-based pathologies. Additionally, their homing and immunomodulatory properties can be exploited in cancer malignancies to transport pharmacological entities, produce anti-neoplastic agents, or induce anti-tumor immunity. Herein, we create a portfolio for MSC properties, showcasing their distinct multiple therapeutic utilities and successes/challenges thereof in both animal studies and clinical trials. We further highlight the promising potential of MSCs not only in cancer management but also in instigating tumor-specific immunity - i.e., cancer vaccination. Finally, we reflect on the possible reasons impeding the clinical advancement of MSC-based cancer vaccines to assist in contriving novel methodologies from which a therapeutic milestone might emanate.

The effect of human wharton's jelly-derived mesenchymal stem cells on MC4R, NPY, and LEPR gene expression levels in rats with streptozotocin-induced diabetes

OBJECTIVES

Type 1 diabetes (T1D) is an autoimmune disease resulting from inflammatory destruction of islets β-cells. Nowadays, progress in cell therapy, especially mesenchymal stem cells (MSCs) proposes numerous potential remedies for T1D. We aimed to investigate the combination therapeutic effect of these cells with insulin and metformin on neuropeptide Y, melanocortin-4 receptor, and leptin receptor genes expression in TID.

MATERIALS AND METHODS

One hundreds male rats were randomly divided into seven groups: the control, diabetes, insulin (Ins.), insulin+metformin (Ins.Met.), Wharton's Jelly-derived MSCs (WJ-MSCs), insulin+metformin+WJ-MSCs (Ins.Met.MSCs), and insulin+WJ-MSCs (Ins.MSCs). Treatment was performed from the first day after diagnosis as diabetes. Groups of the recipient WJ-MSCs were intraportally injected with 2× 10⁶ MSCs/kg at the 7th and 28th days of study. Fasting blood sugar was monitored and tissues and genes analysis were performed.

RESULTS

The blood glucose levels were slightly decreased in all treatment groups within 20th and 45th days compared to the diabetic group. The C-peptide level enhanced in these groups compared to the diabetic group, but this increment in Ins.MSCs group on the 45th days was higher than other groups. The expression level of melanocortin-4 receptor and leptin receptor genes meaningfully up-regulated in the treatment groups, while the expression of neuropeptide Y significantly down-regulated in the treatment group on both times of study.

CONCLUSION

Our data exhibit that infusion of MSCs and its combination therapy with insulin might ameliorate diabetes signs by changing the amount of leptin and subsequent changes in the expression of neuropeptide Y and melanocortin-4 receptor.

Therapeutic Mesenchymal Stromal Cells for Immunotherapy and for Gene and Drug Delivery

Mesenchymal stromal cells (MSCs) possess several fairly unique properties that, when combined, make them ideally suited for cellular-based immunotherapy and as vehicles for gene and drug delivery for a wide range of diseases and disorders. Key among these are: (1) their relative ease of isolation from a variety of tissues; (2) the ability to be expanded in culture without a loss of functionality, a property that varies to some degree with tissue source; (3) they are relatively immune-inert, perhaps obviating the need for precise donor/recipient matching; (4) they possess potent immunomodulatory functions that can be tailored by so-called licensing in vitro and in vivo; (5) the efficiency with which they can be modified with viral-based vectors; and (6) their almost uncanny ability to selectively home to damaged tissues, tumors, and metastases following systemic administration. In this review, we summarize the latest research in the immunological properties of MSCs, their use as immunomodulatory/anti-inflammatory agents, methods for licensing MSCs to customize their immunological profile, and their use as vehicles for transferring both therapeutic genes in genetic disease and drugs and genes designed to destroy tumor cells.

The Potential of Mesenchymal Stem Cells to Treat Systemic Inflammation in Horses

One hallmark of mesenchymal stem cells (MSCs) is the ability to differentiate into multiple tissue types which assists in tissue regeneration. Another hallmark of MSCs is their potent anti-inflammatory and immunomodulatory properties and the potential to treat inflammatory, immune-mediated, and ischemic conditions. In equine practice, MSCs have shown efficacy in the treatment of musculoskeletal disorders such as tendinopathy, meniscal tears and cartilage injury. However, there are many equine disease processes and conditions that may benefit from the immunomodulatory properties of MSCs. Examples include conditions associated with overwhelming acute inflammatory response such as systemic inflammatory response syndrome to chronic diseases characterized by a prolonged low level of inflammation such as equine asthma and recurrent uveitis. For the acute inflammatory response processes, there is often high morbidity and mortality with no effective immunomodulatory treatment to prevent the overwhelming synthesis of proinflammatory mediators. For chronic inflammatory disease processes, frequently long-term corticosteroid treatment is the therapeutic mainstay, with serious potential complications. Thus, there is an unmet need for alternative anti-inflammatory treatments for both acute and chronic illnesses in horses. While MSCs show promise for such conditions, much research is needed before a clinically safe and effective treatment will be available. Optimal MSC tissue source, patient vs. donor source (autologous vs. allogeneic) and cell growth conditions need to be determined for each problem. For immediate use, allogeneic MSC treatments is preferable, but immune tolerance and adequate safety require further study. MSC collection and cryopreservation from horses before they are injured or ill, whether from umbilical cord tissue, bone marrow or adipose might become more widespread. Once these fundamental approaches to treating specific diseases with MSCs are determined, the route of administration, dose and timing of administration also need to be studied. To provide a framework for development of MSC immunomodulatory treatments, this article reviews the current understanding of equine MSC anti-inflammatory and immunomodulatory properties and proposes how MSC therapy may be further developed to treat acute onset systemic inflammatory processes and chronic inflammatory diseases.

Human lung epithelial BEAS-2B cells exhibit characteristics of mesenchymal stem cells

BEAS-2B was originally established as an immortalized but non-tumorigenic epithelial cell line from human bronchial epithelium. Because of general recognition for its bronchial epithelial origin, the BEAS-2B cell line has been widely used as an in vitro cell model in a large variety of studies associated with respiratory diseases including lung carcinogenesis. However, very few studies have discussed non-epithelial features of BEAS-2B cells, especially the features associated with mesenchymal stem cells (MSCs), which represent a group of fibroblast-like cells with limited self-renewal and differentiation potential to various cell lineages. In this study, we compared BEAS-2B with a human umbilical cord-derived MSCs (hMSCs) cell line, hMSC1, which served as a representative of hMSCs in terms of expressing common features of hMSCs. It was observed that both BEAS-2B and hMSC1 shared the same expression profile of surface markers of hMSCs and exhibited similar osteogenic and adipogenic differentiation potential. In addition, like hMSC1, the BEAS-2B cell line exhibited suppressive activities on proliferation of mitogen-activated total T lymphocytes as well as Th1 lymphocytes, and IFNγ-induced expression of IDO1, all thus demonstrating that BEAS-2B cells exhibited an almost identical characteristic profile with hMSCs, even though, there was a clear difference between BEAS-2B and hMSCs in the effects on type 2 macrophage polarization. Most importantly, the hMSCs features of BEAS-2B were unlikely a consequence of epithelial-mesenchymal transition. Therefore, this study provided a set of evidence to provoke reconsideration of epithelial origin of BEAS-2B.

Extracellular Vesicles from Mesenchymal Stem Cells as Novel Treatments for Musculoskeletal Diseases

Mesenchymal stem/stromal cells (MSCs) represent a promising therapy for musculoskeletal diseases. There is compelling evidence indicating that MSC effects are mainly mediated by paracrine mechanisms and in particular by the secretion of extracellular vesicles (EVs). Many studies have thus suggested that EVs may be an alternative to cell therapy with MSCs in tissue repair. In this review, we summarize the current understanding of MSC EVs actions in preclinical studies of (1) immune regulation and rheumatoid arthritis, (2) bone repair and bone diseases, (3) cartilage repair and osteoarthritis, (4) intervertebral disk degeneration and (5) skeletal muscle and tendon repair. We also discuss the mechanisms underlying these actions and the perspectives of MSC EVs-based strategies for future treatments of musculoskeletal disorders.

Therapeutic Application of Mesenchymal Stem Cells Derived Extracellular Vesicles for Immunomodulation

The immunosuppressive potential of mesenchymal stem cells has been extensively investigated in many studies in vivo and in vitro. In recent years, a variety preclinical and clinical studies have demonstrated that mesenchymal stem cells ameliorate immune-mediated disorders, including autoimmune diseases. However, to date mesenchymal stem cells have not become a widely used therapeutic agent due to safety challenges, high cost and difficulties in providing long term production. A key mechanism underpinning the immunomodulatory effect of MSCs is the production of paracrine factors including growth factors, cytokines, chemokines, and extracellular vesicles (EVs). MSCs derived EVs have become an attractive therapeutic agent for immunomodulation and treatment of immune-mediated disorders. In addition to many preclinical studies of MSCs derived EVs, their beneficial effects have been observed in patients with both acute graft-vs.-host disease and chronic kidney disease. In this review, we discuss the current findings in the field of MSCs derived EVs-based therapies in immune-mediated disorders and approaches to scale EV production for clinical use.

The Role of Growth Hormone in Mesenchymal Stem Cell Commitment

Growth hormone (GH) is best known for its prominent role in promoting prepubertal growth and in regulating body composition and metabolism during adulthood. In recent years, the possible role of GH in the modulation of mesenchymal stem cell (MSC) commitment has gained interest. MSCs, characterized by active self-renewal and differentiation potential, express GH receptors. In MSCs derived from different adult tissues, GH induces an inhibition of adipogenic differentiation and favors MSC differentiation towards osteogenesis. This activity of GH indicates that regulation of body composition by GH has already started in the tissue progenitor cells. These findings have fostered research on possible uses of MSCs treated with GH in those pathologies, where a lack of or delays in bone repair occur. After an overview of GH activities, this review will focus on the research that has characterized GH’s effects on MSCs and on preliminary studies on the possible application of GH in bone regenerative medicine.

Natural Compounds as a Strategy to Optimize "In Vitro" Expansion of Stem Cells

The efficient use of stem cells for transplantation is often limited by the relatively low number of stem cells collected. The ex vivo expansion of human stem cells for clinical use is a potentially valuable approach to increase stem cell number. Currently, most of the procedures used to expand stem cells are carried out using a 21% oxygen concentration, which is about 4- to 10-fold greater than the concentration characteristic of their natural niches. Hyperoxia might cause oxidative stress with a deleterious effect on the physiology of cultured stem cells. In this review, we investigate and critically examine the available information on the ability of natural compounds to counteract hyperoxia-induced damage in different types of stem cells ex vivo. In particular, we focused on proliferation and stemness maintenance in an attempt to draw up useful indications to define new culture media with a promoting activity on cell expansion in vitro.

Low-Dose Pesticide Mixture Induces Accelerated Mesenchymal Stem Cell Aging In Vitro

The general population is chronically exposed to multiple environmental contaminants such as pesticides. We have previously demonstrated that human mesenchymal stem cells (MSCs) exposed in vitro to low doses of a mixture of seven common pesticides showed a permanent phenotype modification with a specific induction of an oxidative stress-related senescence. Pesticide mixture also induced a shift in MSC differentiation toward adipogenesis. Thus, we hypothesized that common combination of pesticides may induce a premature cellular aging of adult MSCs. Our goal was to evaluate if the prolonged exposure to pesticide mixture could accelerate aging-related markers and in particular deteriorate the immunosuppressive properties of MSCs. MSCs exposed to pesticide mixture, under long-term culture and obtained from aging donor, were compared by bulk RNA sequencing analysis. Aging, senescence, and immunomodulatory markers were compared. The protein expression of cellular aging-associated metabolic markers and immune function of MSCs were analyzed. Functional analysis of the secretome impacts on immunomodulatory properties of MSCs was realized after 21 days' exposure to pesticide mixture. The RNA sequencing analysis of MSCs exposed to pesticide showed some similarities with cells from prolonged culture, but also with the MSCs of an aged donor. Changes in the metabolic markers MDH1, GOT and SIRT3, as well as an alteration in the modulation of active T cells and modifications in cytokine production are all associated with cellular aging. A modified functional profile was found with similarities to aging process. Stem Cells 2019;37:1083-1094.

Intranasal Administration of Mesenchymal Stem Cells Ameliorates the Abnormal Dopamine Transmission System and Inflammatory Reaction in the R6/2 Mouse Model of Huntington Disease

Intrastriatal administration of mesenchymal stem cells (MSCs) has shown beneficial effects in rodent models of Huntington disease (HD). However, the invasive nature of surgical procedure and its potential to trigger the host immune response may limit its clinical use. Hence, we sought to evaluate the non-invasive intranasal administration (INA) of MSC delivery as an effective alternative route in HD. GFP-expressing MSCs derived from bone marrow were intranasally administered to 4-week-old R6/2 HD transgenic mice. MSCs were detected in the olfactory bulb, midbrain and striatum five days post-delivery. Compared to phosphate-buffered saline (PBS)-treated littermates, MSC-treated R6/2 mice showed an increased survival rate and attenuated circadian activity disruption assessed by locomotor activity. MSCs increased the protein expression of DARPP-32 and tyrosine hydroxylase (TH) and downregulated gene expression of inflammatory modulators in the brain 7.5 weeks after INA. While vehicle treated R6/2 mice displayed decreased Iba1 expression and altered microglial morphology in comparison to the wild type littermates, MSCs restored both, Iba1 level and the thickness of microglial processes in the striatum of R6/2 mice. Our results demonstrate significantly ameliorated phenotypes of R6/2 mice after MSCs administration via INA, suggesting this method as an effective delivering route of cells to the brain for HD therapy.

[Analysis of Biological Properties of Human Adult Mesenchymal Stem Cells and Their Effect on Mouse Hind Limb Ischemia]

BACKGROUND

Due to their self-renewal, proliferation, differentiation, and angiogenesis-inducing capacity, human adipose mesenchymal stem cells (AMSC) have potential clinical applications in the treatment of limb ischemia. AMSC from healthy donors have been shown to induce neovascularization in animal models. However, when cells were obtained from donors suffering from any pathology, their autologous application showed limited effectiveness. We studied whether liposuction niche and obesity could determine the regenerative properties of cells meaning that not all cell batches are suitable for clinical practice.

METHODS

AMSC obtained from 10 donors, obese and healthy, were expanded in vitro following a good manufacturing practice-like production protocol. Cell viability, proliferation kinetics, morphological analysis, phenotype characterization, and stemness potency were assessed over the course of the expansion process. AMSC selected for having the most suitable biological properties were used as an experimental treatment in a preclinical mouse model of hind limb ischemia.

RESULT

All cell batches were positively characterized as mesenchymal stem cells, but not all of them showed the same properties or were successfully expanded in vitro, depending on the characteristics of the donor and the extraction area. Notably, AMSC from the abdomen of obese donors showed undesirable biological properties. AMSC with low duplication times and multilineage differentiation potential and forming large densely packed colonies, were able, following expansion in vitro, to increase neovascularization and repair when implanted in the ischemic tissue of mice.

CONCLUSION

An extensive AMSC biological properties study could be useful to predict the potential clinical efficacy of cells before in vivo transplantation. Thus, peripheral ischemia and possibly other pathologies could benefit from stem cell treatments as shown in our preclinical model in terms of tissue damage repair and regeneration after ischemic injury.

Serum IFN-γ levels predict the therapeutic effect of mesenchymal stem cell transplantation in active rheumatoid arthritis

BACKGROUND

To explore the mechanism of the different clinical efficacies of mesenchymal stem cell transplantation (MSCT) and identify a possible serum biomarker for predicting the therapeutic effect of MSCT in rheumatoid arthritis (RA) patients.

METHODS

A total of 105 patients with persistently active RA and poor responses to traditional medication were randomly divided into MSCT and control groups. Outcomes were evaluated according to the 28-joint Disease Activity Score and Health Assessment Questionnaire, serological indicators, regulatory T cell (Treg) to T helper 17 (Th17) cell ratio, and inflammatory cytokine levels. Twelve weeks after MSCT, the outcomes of the MSCT group were evaluated according to the European League against Rheumatism response criteria. Patients with a good or moderate response were added to the response group, and those with no response were added to the no-response group.

RESULTS

No serious adverse events were reported for either MSCT subgroup (28 in the response group and 24 in the no-response group). The therapeutic effects lasted for 48 weeks without continuous administration. Notably, a transient increase in serum IFN-γ (>2 pg/ml) levels was observed in the response group, but not in the no-response group. Furthermore, an increase in IL-10 levels and the Treg/Th17 ratio and a reduction in IL-6 levels appeared 2-3 weeks after the transient IFN-γ increase.

CONCLUSIONS

Allogeneic MSCT is safe and feasible, and we propose high serum IFN-γ levels as a potent biomarker for predicting MSCT response. Trial registration chictr.org, ChiCTR-ONC-16008770. Registered 3 July 2016, http://www.chictr.org.cn/showproj.aspx?proj=14820.

Allogeneic transplantation of mobilized dental pulp stem cells with the mismatched dog leukocyte antigen type is safe and efficacious for total pulp regeneration

Background

We recently demonstrated that autologous transplantation of mobilized dental pulp stem cells (MDPSCs) was a safe and efficacious potential therapy for total pulp regeneration in a clinical study. The autologous MDPSCs, however, have some limitations to overcome, such as limited availability of discarded teeth from older patients. In the present study, we investigated whether MDPSCs can be used for allogeneic applications to expand their therapeutic use.

Methods

Analysis of dog leukocyte antigen (DLA) was performed using polymerase chain reaction from blood. Canine allogeneic MDPSCs with the matched and mismatched DLA were transplanted with granulocyte-colony stimulating factor in collagen into pulpectomized teeth respectively (n = 7, each). Results were evaluated by hematoxylin and eosin staining, Masson trichrome staining, PGP9.5 immunostaining, and BS-1 lectin immunostaining performed 12 weeks after transplantation. The MDPSCs of the same DLA used in the first transplantation were further transplanted into another pulpectomized tooth and evaluated 12 weeks after transplantation.

Results

There was no evidence of toxicity or adverse events of the allogeneic transplantation of the MDPSCs with the mismatched DLA. No adverse event of dual transplantation of the MDPSCs with the matched and mismatched DLA was observed. Regenerated pulp tissues including neovascularization and neuronal extension were quantitatively and qualitatively similar at 12 weeks in both matched and mismatched DLA transplants. Regenerated pulp tissue was similarly observed in the dual transplantation as in the single transplantation of MDPSCs both with the matched and mismatched DLA.

Conclusions

Dual allogeneic transplantation of MDPSCs with the mismatched DLA is a safe and efficacious method for total pulp regeneration.

Electronic supplementary material

The online version of this article (10.1186/s13287-018-0855-8) contains supplementary material, which is available to authorized users.