Mesenchymal stromal cells for treatment of arthritis

Exploring the therapeutic potential of regulatory T cell in rheumatoid arthritis: Insights into subsets, markers, and signaling pathways

Rheumatoid arthritis (RA) is a complex autoimmune inflammatory rheumatic disease characterized by an imbalance between immunological reactivity and immune tolerance. Regulatory T cells (Tregs), which play a crucial role in controlling ongoing autoimmunity and maintaining peripheral tolerance, have shown great potential for the treatment of autoimmune inflammatory rheumatic diseases such as RA. This review aims to provide an updated summary of the latest insights into Treg-targeting techniques in RA. We focus on current therapeutic strategies for targeting Tregs based on discussing their subsets, surface markers, suppressive function, and signaling pathways in RA.

Mesenchymal Stem Cells in the Pathogenesis and Therapy of Autoimmune and Autoinflammatory Diseases

Mesenchymal stem cells (MSCs) modulate immune responses and maintain self-tolerance. Their trophic activities and regenerative properties make them potential immunosuppressants for treating autoimmune and autoinflammatory diseases. MSCs are drawn to sites of injury and inflammation where they can both reduce inflammation and contribute to tissue regeneration. An increased understanding of the role of MSCs in the development and progression of autoimmune disorders has revealed that MSCs are passive targets in the inflammatory process, becoming impaired by it and exhibiting loss of immunomodulatory activity. MSCs have been considered as potential novel cell therapies for severe autoimmune and autoinflammatory diseases, which at present have only disease modifying rather than curative treatment options. MSCs are emerging as potential therapies for severe autoimmune and autoinflammatory diseases. Clinical application of MSCs in rare cases of severe disease in which other existing treatment modalities have failed, have demonstrated potential use in treating multiple diseases, including rheumatoid arthritis, systemic lupus erythematosus, myocardial infarction, liver cirrhosis, spinal cord injury, multiple sclerosis, and COVID-19 pneumonia. This review explores the biological mechanisms behind the role of MSCs in autoimmune and autoinflammatory diseases. It also covers their immunomodulatory capabilities, potential therapeutic applications, and the challenges and risks associated with MSC therapy.

Haematopoietic stem cell transplantation in paediatric rheumatic disease

PURPOSE OF REVIEW

A small proportion of children affected by rheumatic diseases suffer from severe, progressive disease, resistant to conventional antirheumatic therapies and to biologic agents interfering with inflammatory cytokines, costimulatory molecules expressed on immune system cells and intracellular signalling pathways. Adding to the poor prognosis is a high risk from significant morbidity and mortality associated with long-term treatment with multiple, often combined anti-inflammatory and immunosuppressive agents. Carefully selected patients from this unfortunate group may benefit from treatment with haematopoietic stem cell transplantation.

RECENT FINDINGS

The majority of patients with severe paediatric rheumatic and autoinflammatory diseases treated with autologous and/or allogeneic haematopoietic stem cell transplantation achieved long-term remission. However, the incidence of disease relapse and transplant related morbidity and mortality is still significant.

SUMMARY

Careful patient and donor selection, timing of the transplant earlier in the course of disease rather than the 'last resort' and choosing the most suitable conditioning regimen for each individual patient are the major factors favouring successful outcome. Close co-operation between the patients, their family, and involved medical teams is essential.

The Sufficient Immunoregulatory Effect of Autologous Bone Marrow-Derived Mesenchymal Stem Cell Transplantation on Regulatory T Cells in Patients with Refractory Rheumatoid Arthritis

Rheumatoid arthritis (RA) is an advanced autoimmune disease described by joint involvement. The special properties of mesenchymal stem cells (MSCs) introduced them as a potential therapeutic candidate for RA. In this study, a single dose of autologous MSCs isolated from bone marrow (autologous BM-MSCs, 1 × 10⁶ per kg) was injected intravenously into 13 patients suffering from refractory RA who were followed up within 12 months after the intervention to evaluate immunological elements. Our results showed that the gene expression of forkhead box P3 (FOXP3) in peripheral blood mononuclear cells (PBMCs) considerably increased at month 12. We found a substantial increasing trend in the culture supernatant levels of IL-10 and transforming growth factor-beta 1 (TGF-β1) in PBMCs from the beginning of the intervention up to the end. Our data may reflect the sufficient immunoregulatory effect of autologous BM-MSCs on regulatory T cells in patients suffering from refractory RA.

Immunomodulatory benefits of mesenchymal stem cells treated with Caffeine in adjuvant-induced arthritis

PURPOSE

We intend to assess the effect of the conditioned medium of Caffeine pulsed MSCS in the amelioration of rheumatoid arthritis (RA)-afflicted rats.

METHODS

MSCs were incubated with 0, 0.1, 0.5 or 1 mM Caffeine for 2 weeks. RA was induced by the injection of complete Freund's adjuvant (CFA) into the base of the tail of Wistar rats. According to in vitro studies, RA rats were intraperitoneally treated with MSCs, Caffeine (0.5 mM) pulsed MSCs or vehicle on day 14 when all rats had shown signs of RA.

RESULTS

Our results suggest that the least effective dose concentration of Caffeine that can induce potent anti-inflammatory property in the MSC population is 0.5 mM. Without any significant impact on the vitality or MScs' marker, Caffeine at this concentration could induce lower levels of IFN-γ, IL-6, and IL-1β and a higher level of IDO, TGF-β, and IL-10 compared to other groups. Therefore, MSCs pulsed with Caffeine at 0.5 mM concentration was selected for in vitro studies. Caffeine pulsed MSCs could reduce the severity of the disease and improve weight-gaining more profoundly than treatment with MSCs alone. Furthermore, Caffeine pulsed MSCs caused a significant reduction in the serum levels C-reactive protein, Nitric oxide, Myeloperoxidase, TNF-α and conversely led a significant increase in the levels of IL-10 more prominent than the similar findings brought about by MSCs alone.

CONCLUSION

In general, caffeine-treated MSCs may be a promising strategy for cell-based therapy of RA.

Check-control of inflammation displayed by bone marrow mesenchymal stem cells in rheumatoid arthritis patients

Background: Mesenchymal stem cells (MSCs) are a promising treatment of different musculoskeletal diseases including osteoarthritis and rheumatoid arthritis (RA). Results from different approaches in this treatment have been not conclusive. Aim: To analyze factors related to interactions between peripheral blood mononuclear cells (PBMCs) and MSCs and the influence of cellular activation. Materials & methods: PBMCs from RA patients and healthy controls (HC) were obtained. MSCs from bone marrow (BM-MSCs) were obtained from six donors. CD4, CD25, CD69 and CD127 expression was measured by flow cytometry. Repeated measures analysis of variance (ANOVA) models were performed using activation, co-culture with BM-MSCs and time of culture (24 h, 72 h, 6 days) as within-subject variables. Results: PBMCs activated and co-cultured with BM-MSCs showed a lower proportion of CD25-positive and CD25high/CD127low-negative cells in both RA and HC. Additionally, a maintained expression of CD69 was also observed in RA and HC when PBMCs were activated and co-cultured with BM-MSCs. Conclusion: Both PBMC activation grade and RA disease activity influence the immunomodulatory effect of BM-MSCs on T-cell activation.

Comparison of therapeutic effects of different mesenchymal stem cells on rheumatoid arthritis in mice

Background

Rheumatoid arthritis (RA) is a chronic and nonspecific autoimmune disease, which leads to joint destruction and deformity. To investigate the potential of human mesenchymal stem cells (MSCs) as a new therapeutic strategy for patients with RA, we compared the therapeutic effects of bone marrow derived MSCs (BMSCs), umbilical cord derived MSCs (UCs), and stem cells derived from human exfoliated deciduous teeth (SHED) on collagen-induced arthritis (CIA) in mice.

Methods

A total of 24 DBA/1 mice were infused with type II collagen to induce RA in the experimental model. MSC-treated mice were infused with UCs, BMSCs, and SHED, respectively. Bone erosion and joint destruction were measured by micro-computed tomographic (micro-CT) analysis and hematoxylin and eosin staining. The levels of tumor necrosis factor α (TNF-α) and interleukin-1β (IL-1β) were measured by immunohistochemistry and Enzyme-Linked Immunosorbent Assay (ELISA).

Results

Systemic delivery of MSCs significantly improved the severity of the symptoms related to CIA to greater extent compared with the untreated control group. Micro-CT revealed reduced bone erosions in the metatarsophalangeal joints upon treatment with MSCs. Additionally, according to histologic evaluation, reduced synovitis and articular destruction were observed in MSC-treated groups. The levels of TNF-α and IL-1β in the serum and joints decreased with treatment by MSCs.

Conclusion

Our findings suggest that systemic infusion of UCs, BMSCs, and SHED may significantly alleviate the effects of RA. The therapeutic effect of BMSCs was greater than that of SHED, while the UCs were shown to have the best therapeutic effect on CIA mice. In conclusion, compared with BMSCs and SHED, UCs may be a more suitable source of MSCs for the treatment of patients with RA.

Regulatory effects of paeoniflorin-6'-O-benzene sulfonate (CP-25) on dendritic cells maturation and activation via PGE2-EP4 signaling in adjuvant-induced arthritic rats

Rheumatoid arthritis (RA) is a chronic, systemic autoimmune disease. Dendritic cells (DCs) are one of the most powerful antigen-presenting cells, and they play an important role in RA pathogenesis. Prostaglandin E2 (PGE2) is a potent lipid mediator that can regulate the maturation and activation of DCs, but the molecular mechanisms have not been elucidated. In this study, both in vitro and in an RA rat model, we investigated the mechanisms involved by focusing on PGE2-mediated signaling and using a novel anti-inflammatory compound, paeoniflorin-6'-O-benzene sulfonate (CP-25). PGE2 combined with tumor necrosis factor-α promoted DC maturation and activation through EP4-cAMP signaling. Treatment with CP-25 increased the endocytic capacity of DCs induced by PGE2. CP-25 inhibited the potency of DCs induced by the EP4 receptor agonist, CAY10598, to stimulate allogeneic T cells. Consistent with these findings, the CAY10598-induced upregulation of DC surface activation markers and production of IL-23 was significantly inhibited by CP-25 in a concentration-dependent manner. In vivo administration of CP-25 alleviated adjuvant arthritis (AA) in rats through inhibition of DC maturation and activation. Our results indicate that PGE2-EP4-cAMP signal hyperfunction can lead to abnormal activation of DC functions, which correlates with the course of disease in AA rats and provides a possible treatment target. The inhibition of DC maturation and activation by CP-25 interference of the PGE2-EP4 pathway may significantly contribute to the immunoregulatory profile of CP-25 when used to treat RA and other immune cell-mediated disorders.

Amelioration of clinical symptoms of patients with refractory rheumatoid arthritis following treatment with autologous bone marrow-derived mesenchymal stem cells: A successful clinical trial in Iran

Rheumatoid arthritis (RA) is a chronic inflammatory autoimmune arthropathy characterized by synovial hyperplasia leading to functional impairment. Although the exact cause of RA is unknown, there is evidence suggesting the role of T cell subtypes in the pathogenesis of RA. Conventional therapy in some RA patients is associated with mild or severe side effects, and resistance of some patients has been reported to these types of therapy. The therapeutic potential of mesenchymal stem cells (MSCs) introduced them as a novel therapeutic choice for the treatment of rheumatic diseases. The aim of our study was to evaluate the effects of intravenous administration of autologous bone marrow-derived MSCs on the immunological, clinical and para-clinical factors such as regulatory T cells, Th17 cells, CD8+ T cells, CD4+ T cells, disease activity score 28-erythrocyte sedimentation rate (DAS28-ESR), visual analogue scale (VAS), ESR, C-reactive protein (CRP), rheumatoid factor (RF), and anti-cyclic citrullinated peptide (anti-CCP) antibodies in patients with refractory RA. Nine refractory RA patients with no other rheumatologic disorders were included in this study. All patients received a single intravenous dose of 1 × 10⁶ autologous bone marrow-derived MSCs/kg, and were followed up at 1, 6 and 12 months after injection of MSCs. We found a significant decreasing trend in Th17 percentage and geometric mean fluorescence intensity for IL-17A following injection of MSCs at 12 months compared to the time point zero. Furthermore, a significant increase in regulatory T cells percentage was observed at the end of the first month after the intervention. DAS28-ESR decreased significantly at 1 and 12 months after MSC therapy. VAS score showed a significant decreasing trend during the follow-up periods. No significant difference was found for serum CRP and anti-CCP levels after the intervention. In conclusion, our data indicated that clinical symptoms were significantly ameliorated following the intravenous injection of autologous bone marrow-derived MSCs to the patients with refractory RA.

Role of Stem Cells in Pathophysiology and Therapy of Spondyloarthropathies-New Therapeutic Possibilities?

Considerable progress has been made recently in understanding the complex pathogenesis and treatment of spondyloarthropathies (SpA). Currently, along with traditional disease modifying anti-rheumatic drugs (DMARDs), TNF-α, IL-12/23 and IL-17 are available for treatment of such diseases as ankylosing spondylitis (AS) and psoriatic arthritis (PsA). Although they adequately control inflammatory symptoms, they do not affect the abnormal bone formation processes associated with SpA. However, the traditional therapeutic approach does not cover the regenerative treatment of damaged tissues. In this regards, stem cells may offer a promising, safe and effective therapeutic option. The aim of this paper is to present the role of mesenchymal stromal cells (MSC) in pathogenesis of SpA and to highlight the opportunities for using stem cells in regenerative processes and in the treatment of inflammatory changes in articular structures.

New frontiers in the treatment of systemic juvenile idiopathic arthritis

Systemic juvenile idiopathic arthritis (sJIA) and its most significant complication, macrophage activation syndrome (MAS), have traditionally been treated with steroids and non-steroidal anti-inflammatory medications. However, the introduction of biologic medications that inhibit specific cytokines, such interleukins 1 and 6, has changed the treatment paradigm for sJIA patients. In this review, we discuss the therapies currently used in the treatment of sJIA as well as novel targets and approaches under consideration, including mesenchymal stromal cell therapy and JAK inhibitors. We also discuss targeting cytokines that have been implicated in MAS, such as interferon gamma and interleukin 18.

Intravenous administration of expanded allogeneic adipose-derived mesenchymal stem cells in refractory rheumatoid arthritis (Cx611): results of a multicentre, dose escalation, randomised, single-blind, placebo-controlled phase Ib/IIa clinical trial

OBJECTIVES

To evaluate the safety and tolerability of the intravenous administration of Cx611, a preparation of allogeneic expanded adipose-derived stem cells (eASCs), in patients with refractory rheumatoid arthritis (RA), as well as to obtain preliminary clinical efficacy data in this population.

METHODS

It is a multicentre, dose escalation, randomised, single-blind (double-blind for efficacy), placebo-controlled, phase Ib/IIa clinical trial. Patients with active refractory RA (failure to at least two biologicals) were randomised to receive three intravenous infusions of Cx611: 1 million/kg (cohort A), 2 million/kg (cohort B), 4 million/kg (cohort C) or placebo, on days 1, 8 and 15, and they were followed for therapy assessment for 24 weeks.

RESULTS

Fifty-three patients were treated (20 in cohort A, 20 in cohort B, 6 in cohort C and 7 in placebo group). A total of 141 adverse events (AEs) were reported. Seventeen patients from the group A (85%), 15 from the group B (75%), 6 from the group C (100%) and 4 from the placebo group (57%) experienced at least one AE.Eight AEs from 6 patients were grade 3 in intensity (severe), 5 in cohort A (lacunar infarction, diarrhoea, tendon rupture, rheumatoid nodule and arthritis), 2 in cohort B (sciatica and RA) and 1 in the placebo group (asthenia). Only one of the grade 3 AEs was serious (the lacunar infarction). American College of Rheumatology 20 responses for cohorts A, B, C and placebo were 45%, 20%, 33% and 29%, respectively, at month 1, and 25%, 15%, 17% and 0%, respectively, at month 3.

CONCLUSIONS

The intravenous infusion of Cx611 was in general well tolerated, without evidence of dose-related toxicity at the dose range and time period studied. In addition, a trend for clinical efficacy was observed. These data, in our opinion, justify further investigation of this innovative therapy in patients with RA.

TRIAL REGISTRATION NUMBERS

EudraCT: 2010-021602-37; NCT01663116; Results.

Adipose-derived mesenchymal stromal cells modulate experimental autoimmune arthritis by inducing an early regulatory innate cell signature

Modulation of innate immune responses in rheumatoid arthritis and other immune-mediated disorders is of critical importance in the clinic since a growing body of information has shown the key contribution of dysregulated innate responses in the progression of the disease. Mesenchymal stromal cells (MSCs) are the focus of intensive efforts worldwide due to their key role in tissue regeneration and modulation of inflammation. In this study, we define innate immune responses occurring during the early course of treatment with a single dose of expanded adipose-derived MSCs (eASCs) in established collagen-induced arthritis. eASCs delay the progression of the disease during the early phase of the disease. This is accompanied by a transient induction of Ly6C⁺ monocytes that differentiate into IL10⁺F4/80⁺ cells in arthritic mice. Strikingly, the induced IL10⁺F4/80⁺ myeloid cells preferentially accumulated in the draining lymph nodes. This effect was accompanied with a concomitant declining of their frequencies in the spleens. Our results show that eASCs attenuate the arthritic process by inducing an early innate cell signature that involves a transient induction of Ly6C⁺ monocytes in periphery that differentiate into IL10⁺F4/80⁺ macrophages. Our findings demonstrate that early regulatory innate cell responses, involving the monocyte compartment, are targeted by the eASCs during the onset of collagen-induced inflammation.