Transplantation of umbilical cord mesenchymal stem cells alleviates lupus nephritis in MRL/lpr mice

Enhanced renoprotective effect of IGF-1 modified human umbilical cord-derived mesenchymal stem cells on gentamicin-induced acute kidney injury

The therapeutic action of umbilical cord-derived mesenchymal stem cells (UC-MSCs) against acute kidney injury (AKI) has been demonstrated by several groups. However, how to further enhance the renoprotective effect of UC-MSCs and improve the therapy effect, are still unclear. In this study, we mainly investigated whether insulin-like growth factor-1 (IGF-1)-modified UC-MSCs hold an enhanced protective effect on gentamicin-induced AKI in vivo. Our results indicated that the IGF-1 overexpression could enhance the therapeutic action of human UC-MSCs, and the AKI rats treated with IGF-1-overexpressed UC-MSCs (UC-MSCs-IGF-1) showed better recovery of biochemical variables in serum or urine associated with renal function, histological injury and renal apoptosis, compared with AKI rats treated with normal UC-MSCs. RNA microarray analysis indicated that some key genes in the signal pathways associated with anti-oxidation, anti-inflammatory, and cell migratory capacity were up-regulated in UC-MSCs-IGF-1, and the results were further confirmed with qPCR. Furthermore, a series of detection in vitro and in vivo indicated that the UC-MSCs-IGF-1 hold better anti-oxidation, anti-inflammatory, and cell migratory capacity for IGF-1 overexpression. Thus, our study indicated that enhancement of UC-MSCs bioactivities with IGF-1 overexpression could increase the UC-MSCs therapeutic potential and further developed a new therapeutic strategy for the treatment of AKI.

Mesenchymal stem cells and immunomodulation: current status and future prospects

The unique immunomodulatory properties of mesenchymal stem cells (MSCs) make them an invaluable cell type for the repair of tissue/ organ damage caused by chronic inflammation or autoimmune disorders. Although they hold great promise in the treatment of immune disorders such as graft versus host disease (GvHD) and allergic disorders, there remain many challenges to overcome before their widespread clinical application. An understanding of the biological properties of MSCs will clarify the mechanisms of MSC-based transplantation for immunomodulation. In this review, we summarize the preclinical and clinical studies of MSCs from different adult tissues, discuss the current hurdles to their use and propose the future development of pluripotent stem cell-derived MSCs as an approach to immunomodulation therapy.

Update on mesenchymal stem cell-based therapy in lupus and scleroderma

Current systemic therapies are rarely curative for patients with severe life-threatening forms of autoimmune diseases (ADs). During the past 15 years, autologous hematopoietic stem cell transplantation has been demonstrated to cure some patients with severe AD refractory to all other available therapies. As a consequence, ADs such as lupus and scleroderma have become an emerging indication for cell therapy. Multipotent mesenchymal stem cells (MSCs), isolated from bone marrow and other sites, display specific immunomodulation and anti-inflammatory properties and appear as ideal tools to treat such diseases. The present update aims at summarizing recent knowledge acquired in the field of MSC-based therapies for lupus and scleroderma.

Human umbilical cord mesenchymal stem cells improve the immune-associated inflammatory and prothrombotic state in collagen type-Ⅱ-induced arthritic rats

Human umbilical cord mesenchymal stem cells (hUC‑MSCs) hold great potential in the search for therapies to treat refractory diseases, including rheumatoid arthritis (RA), due to their potential regenerative ability and extensive source. However, the role of hUC‑MSCs in vivo and the repair mechanisms for RA remain to be fully elucidated. The present study aimed to determine whether hUC‑MSCs exert immunomodulatory effects and have anti‑inflammatory capabilities in the treatment of embolisms. Following the transplantation of hUC‑MSCs into collagen type Ⅱ‑induced arthritic (CIA) model rats, magnetic resonance imaging (MRI) in vivo was performed, and the levels of interleukin (IL)‑1, IL‑17, tumor necrosis factor (TNF)‑α, vascular endothelial growth factor (VEGF), tissue factor (TF), CD4+CD25+ T cells (Treg) and antithrombin (AT) were measured. Bromodeoxyuridine staining was performed for histopathological examinations. As revealed by immunofluorescence and MRI experiments, the injected hUC‑MSCs preferentially migrated to the inflammatory joint sites of the rats. The Treg cell percentage and AT levels in the hUC‑MSC‑treated group were markedly increased, whereas the levels of IL‑1, IL‑17, TNF‑α, VEGF and TF were decreased compared with those in the CIA model group. The values determined for these parameters in the hUC‑MSC‑treated group returned to approximately the identical values as those of the control group on day 35 post‑therapy. Superparamagnetic iron oxide nanoparticles (SPIONs) may serve as an effective, non‑invasive method for tracking transplanted cells in vivo. The present study provided direct evidence that hUC‑MSCs in the CIA rat model migrated to the inflammatory joint sites, effectively promoting recovery from collagen type II damage and thereby improving the immune‑associated prothrombotic state.

Allogeneic mesenchymal stem cells inhibited T follicular helper cell generation in rheumatoid arthritis

T follicular helper (Tfh) cells provide help for antigen-specific B cells. We have previously shown that Tfh cell frequency was increased and associated with auto-antibodies in patients with rheumatoid arthritis (RA), suggesting a possible involvement of Tfh cells in its pathogenesis. Mesenchymal stem cells (MSCs) represent a promising alternative cell therapy for RA by modulating T and B cell activation and proliferation. However, it remains unknown whether MSCs have immunoregulation on Tfh cells. In this paper, we have demonstrated that allogeneic MSCs could suppress Tfh cell differentiation in RA patients partly via the production of indoleamine 2,3-dioxygenase (IDO). IFNγ generated from Tfh cell differentiation system induced IDO expression on MSCs. MSCs transplantation (MSCT) into collagen-induced arthritis (CIA) mice prevented arthritis progression by inhibiting both the number and function of Tfh cells in vivo. These findings reveal a novel suppressive function of MSCs in Tfh cells, which has implication in understanding the underlying mechanisms of the immunotherapeutic effects of MSCs on RA patients.

Mesenchymal stem cells promote CD206 expression and phagocytic activity of macrophages through IL-6 in systemic lupus erythematosus

Human umbilical cord-derived mesenchymal stem cells (UCMSCs) show therapeutic effects on systemic lupus erythematosus (SLE). Deficiency in functional polarization and phagocytosis in macrophages has been suggested in the pathogenesis of SLE. We found that macrophages from B6.MRL-Fas(lpr) mice exhibited lower level of CD206, the marker for alternatively activated macrophage (AAM, also called M2). In addition, the phagocytic activity of B6.MRL-Fas(lpr) macrophages was also decreased. UCMSC transplantation improved the proportion of CD206(+) macrophages and their phagocytic activity in B6.MRL-Fas(lpr) mice. Importantly, macrophages from SLE patients also showed lower expression of CD206 and reduced phagocytic activity, which were corrected by being co-cultured with UCMSCs in vitro and in SLE patients receiving UCMSC transplantation. Mechanistically, we demonstrated that IL-6 was required for the up-regulation of CD206 expression and phagocytic activity of UCMSC-treated SLE macrophages. Our results indicate that UCMSCs alleviate SLE through promoting CD206 expression and phagocytic activity of macrophages in an IL-6 dependent manner.

Mesenchymal stem cells and adaptive immune responses

Over the past decade, our understanding of the regulatory role of mesenchymal stem cells (MSCs) in adaptive immune responses through both preclinical and clinical studies has dramatically expanded, providing great promise for treating various inflammatory diseases. Most studies are focused on the modulatory effects of these cells on the properties of T cell-mediated immune responses, including activation, proliferation, survival, and subset differentiation. Interestingly, the immunosuppressive function of MSCs was found to be licensed by IFN-γ and TNF-α produced by T cells and that can be further amplified by cytokines such as IL-17. However, the immunosuppressive function of MSCs can be reversed in certain situation, such as suboptimal levels of inflammatory cytokines, or in the presence of immunosuppressive molecules. Here we review the influence of MSCs on adaptive immune system, especially their bidirectional interaction in tuning the immune microenvironment and subsequently repairing damaged tissue. Understanding MSC-mediated regulation of T cells is expected to provide fundamental information for guiding appropriate applications of MSCs in clinical settings.

The parasitic worm product ES-62 targets myeloid differentiation factor 88-dependent effector mechanisms to suppress antinuclear antibody production and proteinuria in MRL/lpr mice

Objective

The hygiene hypothesis suggests that parasitic helminths (worms) protect against the development of autoimmune disease via a serendipitous side effect of worm-derived immunomodulators that concomitantly promote parasite survival and limit host pathology. The aim of this study was to investigate whether ES-62, a phosphorylcholine-containing glycoprotein secreted by the filarial nematode Acanthocheilonema viteae, protects against kidney damage in an MRL/lpr mouse model of systemic lupus erythematosus (SLE).

Methods

MRL/lpr mice progressively produce high levels of autoantibodies, and the resultant deposition of immune complexes drives kidney pathology. The effects of ES-62 on disease progression were assessed by measurement of proteinuria, assessment of kidney histology, determination of antinuclear antibody (ANA) production and cytokine levels, and flow cytometric analysis of relevant cellular populations.

Results

ES-62 restored the disrupted balance between effector and regulatory B cells in MRL/lpr mice by inhibiting plasmablast differentiation, with a consequent reduction in ANA production and deposition of immune complexes and C3a in the kidneys. Moreover, by reducing interleukin-22 production, ES-62 may desensitize downstream effector mechanisms in the pathogenesis of kidney disease. Highlighting the therapeutic importance of resetting B cell responses, adoptive transfer of purified splenic B cells from ES-62–treated MRL/lpr mice mimicked the protection afforded by the helminth product. Mechanistically, this reflects down-regulation of myeloid differentiation factor 88 expression by B cells and also kidney cells, resulting in inhibition of pathogenic cross-talk among Toll-like receptor–, C3a-, and immune complex–mediated effector mechanisms.

Conclusion

This study provides the first demonstration of protection against kidney pathology by a parasitic worm–derived immunomodulator in a model of SLE and suggests therapeutic potential for drugs based on the mechanism of action of ES-62.

Transplantation of mesenchymal stem cells ameliorates secondary osteoporosis through interleukin-17-impaired functions of recipient bone marrow mesenchymal stem cells in MRL/lpr mice

Introduction

Secondary osteoporosis is common in systemic lupus erythematosus and leads to a reduction in quality of life due to fragility fractures, even in patients with improvement of the primary disorder. Systemic transplantation of mesenchymal stem cells could ameliorate bone loss and autoimmune disorders in a MRL/lpr mouse systemic lupus erythematosus model, but the detailed therapeutic mechanism of bone regeneration is not fully understood. In this study, we transplanted human bone marrow mesenchymal stem cells (BMMSCs) and stem cells from exfoliated deciduous teeth (SHED) into MRL/lpr mice and explored their therapeutic mechanisms in secondary osteoporotic disorders of the systemic lupus erythematosus model mice.

Methods

The effects of systemic human mesenchymal stem cell transplantation on bone loss of MRL/lpr mice were analyzed in vivo and ex vivo. After systemic human mesenchymal stem cell transplantation, recipient BMMSC functions of MRL/lpr mice were assessed for aspects of stemness, osteogenesis and osteoclastogenesis, and a series of co-culture experiments under osteogenic or osteoclastogenic inductions were performed to examine the efficacy of interleukin (IL)-17-impaired recipient BMMSCs in the bone marrow of MRL/lpr mice.

Results

Systemic transplantation of human BMMSCs and SHED recovered the reduction in bone density and structure in MRL/lpr mice. To explore the mechanism, we found that impaired recipient BMMSCs mediated the negative bone metabolic turnover by enhanced osteoclastogenesis and suppressed osteoblastogenesis in secondary osteoporosis of MRL/lpr mice. Moreover, IL-17-dependent hyperimmune conditions in the recipient bone marrow of MRL/lpr mice damaged recipient BMMSCs to suppress osteoblast capacity and accelerate osteoclast induction. To overcome the abnormal bone metabolism, systemic transplantation of human BMMSCs and SHED into MRL/lpr mice improved the functionally impaired recipient BMMSCs through IL-17 suppression in the recipient bone marrow and then maintained a regular positive bone metabolism via the balance of osteoblasts and osteoclasts.

Conclusions

These findings indicate that IL-17 and recipient BMMSCs might be a therapeutic target for secondary osteoporosis in systemic lupus erythematosus.

Electronic supplementary material

The online version of this article (doi:10.1186/s13287-015-0091-4) contains supplementary material, which is available to authorized users.

Induction of Apoptosis Coupled to Endoplasmic Reticulum Stress through Regulation of CHOP and JNK in Bone Marrow Mesenchymal Stem Cells from Patients with Systemic Lupus Erythematosus

Previous studies indicated that bone marrow mesenchymal stem cells (BM-MSCs) from patients with systemic lupus erythematosus (SLE) exhibited the phenomenon of apoptosis. In this study, we aimed to investigate whether apoptosis of BM-MSCs from SLE patients were dysregulated. In this paper, endoplasmic reticulum stress (ERS) was evidenced by increased expression of phosphorylated protein kinase RNA-like ER kinase (PERK) and inositol-requiring protein-1 (IRE-1). We also found the activation of downstream target eukaryotic translation initiator factor 2α (eIF 2α) and CCAAT/enhancer-binding protein- (C/EBP-) homologous protein (CHOP) in BM-MSCs from SLE patients. Interestingly, we discovered that 4-phenylbutyric acid (4-PBA), a selective inhibitor of ERS, blocked the apoptosis of BM-MSCs from SLE patients and alleviated the level of Jun N-terminal kinase1/2 (JNK1/2) and CHOP. Furthermore, blockage of PERK signaling expression by siRNA not only significantly reduced the expression of CHOP, but also activated the anti-apoptotic regulator B-cell lymphoma-2 (Bcl-2). Blockage of IRE-1 or JNK1/2 by siRNA resulted in the decreased expression of JNK1/2 and proapoptosis protein Bcl-2 associated protein X (BAX). These results implicated that ERS-mediated apoptosis was a critical determinant of BM-MSCs from SLE patients.

Infusion of Human Bone Marrow-Derived Mesenchymal Stem Cells Alleviates Autoimmune Nephritis in a Lupus Model by Suppressing Follicular Helper T-Cell Development

Systemic lupus erythematosus (SLE) is an autoimmune disease characterized by the production of autoantibodies to components of the cell nucleus. These autoantibodies are predominantly produced with the help of follicular helper T (Tfh) cells and form immune complexes that trigger widespread inflammatory damage, including nephritis. In recent studies, mesenchymal stem cells (MSCs) elicited diverse, even opposing, effects in experimental and clinical SLE. Here we investigated the effect of human bone marrow-derived MSCs (hBM-MSCs) in a murine model of SLE, the F1 hybrid between New Zealand Black and New Zealand White strains (NZB/W). We found that infusion of female NZB/W mice with hBM-MSCs attenuated glomerulonephritis; it also decreased levels of autoantibodies and the incidence of proteinuria and improved survival. These effects coincided with a decrease in Tfh cells and downstream components. Infiltration of long-lived plasma cells into the inflamed kidney was also reduced in the hBM-MSC-treated mice. Importantly, hBM-MSCs directly suppressed the in vitro differentiation of naive CD4(+) T cells toward Tfh cells in a contact-dependent manner. These results suggest that MSCs attenuate lupus nephritis by suppressing the development of Tfh cells and the subsequent activation of humoral immune components. They thus reveal a novel mechanism by which MSCs regulate humoral autoimmune diseases such as SLE.

Mesenchymal stem cells in the treatment of inflammatory and autoimmune diseases in experimental animal models

Multipotent mesenchymal stromal cells [also known as mesenchymal stem cells (MSCs)] are currently being studied as a cell-based treatment for inflammatory disorders. Experimental animal models of human immune-mediated diseases have been instrumental in establishing their immunosuppressive properties. In this review, we summarize recent studies examining the effectiveness of MSCs as immunotherapy in several widely-studied animal models, including type 1 diabetes, experimental autoimmune arthritis, experimental autoimmune encephalomyelitis, inflammatory bowel disease, graft-vs-host disease, and systemic lupus erythematosus. In addition, we discuss mechanisms identified by which MSCs mediate immune suppression in specific disease models, and potential sources of functional variability of MSCs between studies.

Stem cell therapies for systemic lupus erythematosus: current progress and established evidence

Systemic lupus erythematosus is a multisystem autoimmune disease that, despite the advances in immunosuppressive medical therapies, remains potentially fatal in some patients, especially in treatment-refractory patients. In recent years, hematopoietic stem cells and, most recently, mesenchymal stem cells have been used to treat drug-resistant cases. Some progress was made, but there are still some issues to be resolved in the clinic.

Immunomodulatory effects of stem cells

Adult-derived mesenchymal stem cells have received considerable attention over the past two decades for their potential use in tissue engineering, principally because of their potential to differentiate into multiple stromal-cell lineages. Recently, the immunomodulatory properties of mesenchymal stem cells have attracted interest as a unique property of these cells that may be harnessed for novel therapeutic approaches in immune-mediated diseases. Mesenchymal stem cells have been shown to inhibit the proliferation of activated T-cells both in vitro and in vivo but to stimulate T-regulatory cell proliferation. Mesenchymal stem cells are also known to be weakly immunogenic and to exert immunosuppressive effects on B-cells, natural killer cells, dendritic cells and neutrophils through various mechanisms. Furthermore, intravenous administration of allogeneic mesenchymal stem cells has shown a marked suppression of host immune reactions in preclinical animal models of large-organ transplant rejection and in various autoimmune- and inflammatory-based diseases. Some clinical trials utilizing human mesenchymal stem cells have also produced promising outcomes in patients with graft-vs.-host disease and autoimmune diseases. Mesenchymal stem cells identified from various dental tissues, including periodontal ligament stem cells, also possess multipotent and immunomodulatory properties. Hence, dental mesenchymal stem cells may represent an alternate cell source, not only for tissue regeneration but also as therapies for autoimmune- and inflammatory-mediated diseases. These findings have elicited interest in dental tissue mesenchymal stem cells as alternative cell sources for modulating alloreactivity during tissue regeneration following transplantation into human leukocyte antigen-mismatched donors. To examine this potential in periodontal regeneration, future work will need to assess the capacity of allogeneic periodontal ligament stem cells to regenerate periodontal ligament in animal models of periodontal disease. The present review describes the immunosuppressive effects of mesenchymal stem cells on various types of immune cells, the potential mechanisms through which they exert their mode of action and the preclinical animal studies and human clinical trials that have utilized mesenchymal stem cells, including those populations originating from dental structures.

Endoplasmic reticulum stress participates in the progress of senescence of bone marrow-derived mesenchymal stem cells in patients with systemic lupus erythematosus

Previous studies suggested that the senescence of bone marrow mesenchymal stem cells (BM-MSCs) played an important role in the pathological process of systemic lupus erythematosus (SLE). However, the molecular mechanisms that govern this phenomenon have not been fully elucidated. Recent studies reported the activation of endoplasmic reticulum stress (ERS) participated in the growth arrest in G1 phase of cell cycle. In this study, we aimed to investigate whether ERS would induce the senescence of BM-MSCs from SLE patients. We found that there was increased expression of Glucose Regulated Protein 78 (GRP 78) in BM-MSCs from SLE patients, which indicated the activation of ERS in BM-MSCs from SLE patients. Accumulation of p27 was also found in BM-MSCs from SLE patients. Interestingly, as a chemical chaperone helping the correct folding of proteins, 4-phenylbutyric acid (4-PBA) partly rescued the senescence of BM-MSCs from SLE patients and alleviated the level of p27. These results implicated ERS-mediated senescence as a critical determinant of BM-MSCs from SLE patients.

Cell-based therapies for experimental chronic kidney disease: a systematic review and meta-analysis

Cell-based therapy is a promising strategy for treating chronic kidney disease (CKD) and is currently the focus of preclinical studies. We performed a systematic review and meta-analysis to evaluate the efficacy of cell-based therapy in preclinical (animal) studies of CKD, and determined factors affecting cell-based therapy efficacy in order to guide future clinical trials. In total, 71 articles met the inclusion criteria. Standardised mean differences (SMD) and 95% confidence intervals (CI) were calculated for outcome parameters including plasma urea, plasma creatinine, urinary protein, blood pressure, glomerular filtration rate, glomerulosclerosis and interstitial fibrosis. Sub-analysis for each outcome measure was performed for model-related factors (species, gender, model and timing of therapy) and cell-related factors (cell type, condition and origin, administration route and regime of therapy). Overall, meta-analysis showed that cell-based therapy reduced the development and progression of CKD. This was most prominent for urinary protein (SMD, 1.34; 95% CI, 1.00–1.68) and urea (1.09; 0.66–1.51), both P<0.001. Changes in plasma urea were associated with changes in both glomerulosclerosis and interstitial fibrosis. Sub-analysis showed that cell type (bone-marrow-derived progenitors and mesenchymal stromal cells being most effective) and administration route (intravenous or renal artery injection) were significant predictors of therapeutic efficacy. The timing of therapy in relation to clinical manifestation of disease, and cell origin and dose, were not associated with efficacy. Our meta-analysis confirms that cell-based therapies improve impaired renal function and morphology in preclinical models of CKD. Our analyses can be used to optimise experimental interventions and thus support both improved preclinical research and development of cell-based therapeutic interventions in a clinical setting.

Adipose tissue-derived mesenchymal stem cells induce expansion of interleukin-10-producing regulatory B cells and ameliorate autoimmunity in a murine model of systemic lupus erythematosus

Mesenchymal stem cells (MSCs) are multipotent cells characterized by immunomodulatory properties and are therefore considered a promising tool for the treatment of autoimmune diseases. One functional B-cell subset, regulatory B cells (Bregs), has recently been shown to restrain excessive inflammatory responses in autoimmune diseases. In the present study, we investigated the impact of human adipose-derived MSCs on Bregs and their therapeutic effect in an animal model of systemic lupus erythematosus (SLE). Coculture of human adipose-derived MSCs with splenocytes from C57BL/6 mice expanded the population of interleukin-10-producing B cells (B10 B cells). In vivo treatment with human adipose-derived MSCs reduced serum anti-double-stranded antibody levels and improved renal pathology of lupus mice (Roquin(san/san) mice). MSCs decreased ICOS(+)CD44(+) follicular helper T cells, Th1 cells and Th17 cells, in spleens of Roquin(san/san) mice. In contrast, MSCs increased Foxp3-expressing regulatory T cells. MSCs also decreased the size and number of germinal centers and effector B cells. As expected, in vivo treatment with MSCs expanded the population of Bregs in spleens of Roquin(san/san) mice. Our results indicate that human adipose-derived MSCs induce the expansion of Bregs and ameliorate autoimmunity in a murine model of SLE. These findings suggest that human adipose-derived MSCs may be a promising therapeutic strategy targeting B-cell-mediated autoimmune diseases such as SLE.

HMGB1 in health and disease

Complex genetic and physiological variations as well as environmental factors that drive emergence of chromosomal instability, development of unscheduled cell death, skewed differentiation, and altered metabolism are central to the pathogenesis of human diseases and disorders. Understanding the molecular bases for these processes is important for the development of new diagnostic biomarkers, and for identifying new therapeutic targets. In 1973, a group of non-histone nuclear proteins with high electrophoretic mobility was discovered and termed high-mobility group (HMG) proteins. The HMG proteins include three superfamilies termed HMGB, HMGN, and HMGA. High-mobility group box 1 (HMGB1), the most abundant and well-studied HMG protein, senses and coordinates the cellular stress response and plays a critical role not only inside of the cell as a DNA chaperone, chromosome guardian, autophagy sustainer, and protector from apoptotic cell death, but also outside the cell as the prototypic damage associated molecular pattern molecule (DAMP). This DAMP, in conjunction with other factors, thus has cytokine, chemokine, and growth factor activity, orchestrating the inflammatory and immune response. All of these characteristics make HMGB1 a critical molecular target in multiple human diseases including infectious diseases, ischemia, immune disorders, neurodegenerative diseases, metabolic disorders, and cancer. Indeed, a number of emergent strategies have been used to inhibit HMGB1 expression, release, and activity in vitro and in vivo. These include antibodies, peptide inhibitors, RNAi, anti-coagulants, endogenous hormones, various chemical compounds, HMGB1-receptor and signaling pathway inhibition, artificial DNAs, physical strategies including vagus nerve stimulation and other surgical approaches. Future work further investigating the details of HMGB1 localization, structure, post-translational modification, and identification of additional partners will undoubtedly uncover additional secrets regarding HMGB1's multiple functions.

Differential efficacy of human mesenchymal stem cells based on source of origin

Mesenchymal stem cells (MSCs) are useful in tissue repair but also possess immunomodulatory properties. Murine and uncontrolled human trials suggest efficacy of MSCs in treating lupus. Autologous cells are preferable; however, recent studies suggest that lupus-derived MSCs lack efficacy in treating disease. Thus, the optimum derivation of MSCs for use in lupus is unknown. It is also unknown which in vitro assays of MSC function predict in vivo efficacy. The objectives for this study were to provide insight into the optimum source of MSCs and to identify in vitro assays that predict in vivo efficacy. We derived MSCs from four umbilical cords, four healthy bone marrows (BMs), and four lupus BMs. In diseased MRL/lpr mice, MSCs from healthy BM and umbilical cords significantly decreased renal disease, whereas lupus BM MSCs only delayed disease. Current in vitro assays did not differentiate efficacy of the different MSCs. However, differences in MSC efficacy were observed in B cell proliferation assays. Our results suggest that autologous MSCs from lupus patients are not effective in treating disease. Furthermore, standard in vitro assays for MSC licensing are not predictive of in vivo efficacy, whereas inhibiting B cell proliferation appears to differentiate effective MSCs from ineffective MSCs.

High level of reactive oxygen species impaired mesenchymal stem cell migration via overpolymerization of F-actin cytoskeleton in systemic lupus erythematosus

Some lines of evidence have demonstrated abnormalities of bone marrow mesenchymal stem cells (MSCs) in systemic lupus erythematosus (SLE) patients, characterized by defective phenotype of MSCs and slower growth with enhanced apoptosis and senescence. However, whether SLE MSCs demonstrate aberrant migration capacity or abnormalities in cytoskeleton are issues that remain poorly understood. In this study, we found that MSCs from SLE patients did show impairment in migration capacity as well as abnormalities in F-actin cytoskeleton, accompanied by a high level of intracellular reactive oxygen species (ROS). When normal MSCs were treated in vitro with H2O2, which increases intracellular ROS level as an oxidant, both reorganization of F-actin cytoskeleton and impairment of migration capability were observed. On the other hand, treatment with N-acetylcysteine (NAC), as an exogenous antioxidant, made F-actin more orderly and increased migration ratio in SLE MSCs. In addition, oral administration of NAC markedly reduced serum autoantibody levels and ameliorated lupus nephritis (LN) in MRL/lpr mice, partially reversing the abnormalities of MSCs. These results indicate that overpolymerization of F-actin cytoskeleton, which may be associated with high levels of ROS, causes impairment in the migration capacity of SLE MSCs and that oral administration of NAC may have potential therapeutic effects on MRL/lpr mice.

Allogeneic mesenchymal stem cell transplantation for lupus nephritis patients refractory to conventional therapy

Allogeneic mesenchymal stem cell transplantation (MSCT) has been shown to be clinically efficacious in the treatment of various autoimmune diseases. Here, we analyzed the role of allogeneic MSCT to induce renal remission in patients with active and refractory lupus nephritis (LN). This is an open-label and single-center clinical trial conducted from 2007 to 2010 in which 81 Chinese patients with active and refractory LN were enrolled. Allogeneic bone marrow- or umbilical cord-derived mesenchymal stem cells (MSCs) were administered intravenously at the dose of 1 million cells per kilogram of bodyweight. All patients were then monitored over the course of 12 months with periodic follow-up visits to evaluate renal remission, as well as possible adverse events. The primary outcome was complete renal remission (CR) and partial remission (PR) at each follow-up, as well as renal flares. The secondary outcome included renal activity score, total disease activity score, renal function, and serologic index. During the 12-month follow-up, the overall rate of survival was 95 % (77/81). Totally, 60.5 % (49/81) patients achieved renal remission during 12-month visit by MSCT. Eleven of 49 (22.4 %) patients experienced renal flare by the end of 12 months after a previous remission. Renal activity evaluated by British Isles Lupus Assessment Group (BILAG) scores significantly declined after MSCT (mean ± SD, from 4.48 ± 2.60 at baseline to 1.09 ± 0.83 at 12 months), in parallel with the obvious amelioration of renal function. Glomerular filtration rate (GFR) improved significantly 12 months after MSCT (mean ± SD, from 58.55 ± 19.16 to 69.51 ± 27.93 mL/min). Total disease activity evaluated by Systemic Lupus Erythematosus Disease Activity Index (SLEDAI) scores also decreased after treatment (mean ± SD, from 13.11 ± 4.20 at baseline to 5.48 ± 2.77 at 12 months). Additionally, the doses of concomitant prednisone and immunosuppressive drugs were tapered. No transplantation-related adverse event was observed. Allogeneic MSCT resulted in renal remission for active LN patients within 12-month visit, confirming its use as a potential therapy for refractory LN.

Stem cell-based cell therapy for glomerulonephritis

Glomerulonephritis (GN), characterized by immune-mediated inflammatory changes in the glomerular, is a common cause of end stage renal disease. Therapeutic options for glomerulonephritis applicable to all cases mainly include symptomatic treatment and strategies to delay progression. In the attempt to yield innovative interventions fostering the limited capability of regeneration of renal tissue after injury and the uncontrolled pathological process by current treatments, stem cell-based therapy has emerged as novel therapy for its ability to inhibit inflammation and promote regeneration. Many basic and clinical studies have been performed that support the ability of various stem cell populations to ameliorate glomerular injury and improve renal function. However, there is a long way before putting stem cell-based therapy into clinical practice. In the present article, we aim to review works performed with respect to the use of stem cell of different origins in GN, and to discuss the potential mechanism of therapeutic effect and the challenges for clinical application of stem cells.

Preclinical efficacy and mechanisms of mesenchymal stem cells in animal models of autoimmune diseases

Mesenchymal stem cells (MSCs) are present in diverse tissues and organs, including bone marrow, umbilical cord, adipose tissue, and placenta. MSCs can expand easily in vitro and have regenerative stem cell properties and potent immunoregulatory activity. They inhibit the functions of dendritic cells, B cells, and T cells, but enhance those of regulatory T cells by producing immunoregulatory molecules such as transforming growth factor-β, hepatic growth factors, prostaglandin E₂, interleukin-10, indolamine 2,3-dioxygenase, nitric oxide, heme oxygenase-1, and human leukocyte antigen-G. These properties make MSCs promising therapeutic candidates for the treatment of autoimmune diseases. Here, we review the preclinical studies of MSCs in animal models for systemic lupus erythematosus, rheumatoid arthritis, Crohn's disease, and experimental autoimmune encephalomyelitis, and summarize the underlying immunoregulatory mechanisms.

Novel approaches to lupus drug discovery using stem cell therapy. Role of mesenchymal-stem-cell-secreted factors

INTRODUCTION

Patients with systemic lupus erythematosus (SLE) are at increased risk for premature death, particularly among young adults, and present dilemmas regarding drug efficacy versus toxicity. Novel therapeutic strategies have included the use of mesenchymal stem cell (MSC) therapies that are promising but still have limitations. In several disease models, it has become apparent that MSCs do not necessarily replace diseased tissues but rather exert complex paracrine effects that are mediated by their extracellular-secreted products.

AREAS COVERED

In this review, the authors highlight the data on MSC treatment of SLE and related mechanisms of actions. This data includes the recent evidence that MSC-secreted factors such as extracellular microvesicles (MVs) are important mediators of MSC therapy. Among MVs, the authors delineate the role of exosomes as triggers of regenerative effects in target cells, mediated by transfer of proteins, mRNAs or microRNAs. The authors also outline some of the biological and regulatory restraints encountered by MSC therapy, in contrast to the potential advantages of MSC-derived exosomes as new therapeutic tools in SLE.

EXPERT OPINION

There is concern about reproducible data on the use of MSC therapy in rheumatic diseases and specifically SLE. Although most experts consider MSCs to be safe, there are still worries over donor variability, immune-mediated rejection, culture-induced senescence, loss of functional properties and genetic instability or eventual malignant transformation. MSC-released factors could avoid most limiting factors associated with cell therapy and are therefore expected to provide a new and safe therapeutic option at an affordable cost.

Transplantation of umbilical cord mesenchymal stem cells alleviates pneumonitis of MRL/lpr mice

OBJECTIVE

To investigate whether the umbilical cord mesenchymal stem cells (UC-MSCs) transplantation in the MRL/lpr mice has effect or not on their pneumonitis and the possible mechanisms underlying this treatment.

METHODS

Twenty four 18-week-old MRL/lpr female mice were divided into three groups as following: the group 2 (UC-MSCT group) have been transplanted with 1×10(6) UC-MSCs through caudal vein, the group 3 (multi-UC-MSCT Group) have been transplanted with 1×10(6) UC-MSCs three times and the group 1 (control group) have been treated with 0.5 mL phosphate buffer saline (PBS) as control. The histopathology of the lung was observed. The pulmonary expression of high mobility group box protein-1 (HMGB-1) was measured by western blot and detected by quantitation real time polymerase chain reaction (PCR). Immunohistochemistry method was used to detect HMGB-1 expressions in pulmo.

RESULTS

In comparision to control ground mice, UC-MSCs significantly reduced interstitial pneumonitis in the MRL/lpr mice. The lung peribronchiolar lesion index of UC-MSCT group (1.40±0.24) and multi-UC-MSCT group (1.02±0.29) were significantly decreased as compared to control group (1.95±0.35) (P<0.01). The perivascular lesion index of UC-MSCT group (1.20±0.18) and multi-UC-MSCT group (1.08±0.16) were also significantly reduced as compared to control group (1.56±0.32) (P=0.018, 0.002) and the lung alveolar areas lesion index of control group (1.72±0.34) was significantly increased as compared to UC-MSCT group (1.30±0.21) and multi-UC-MSCT group (1.05±0.15) (P=0.011, 0.000). The lung HMGB-1 protein in UC-MSCT group (0.32±0.04) and in multi-UC-MSCT group (0.28±0.06) were both significantly decreased as compared to that in control group (0.80±0.21) (P<0.05). The level of HMGB-1 mRNA in UC-MSCT group (4.68±0.37) and in multi-UC-MSCT group (4.35±0.10) lung were both significantly decreased as compared to those in control group (16.29±3.84) (P<0.05). In immunohistochemical staining lung sections, high expression of HMGB-1 was found mainly located in the cytoplasm and extracellular matrix of MRL/lpr mice pulmonary epithelial cells, the expression of HMGB-1 in UC-MSCT group and multi-UC-MSCT group was significantly decreased as compared to that in the control group.

CONCLUSIONS

These findings indicate that UC-MSCs have a therapeutic effect on systemic lupus erythematosus (SLE) pneumonitis, possibly by inhibiting HMGB-1 expression, which suggests a potential application of UC-MSCs in the treatment of human lupus.

Suppression of in vitro murine T cell proliferation by human adipose tissue-derived mesenchymal stem cells is dependent mainly on cyclooxygenase-2 expression

Mesenchymal stem cells (MSCs) of human origin have been frequently applied to experimental animal models to evaluate their immunomodulatory functions. MSCs are known to be activated by cytokines from T cells, predominantly by interferon-γ (IFN-γ), in conjunction with other cytokines such as tumor necrosis factor-α (TNF-α) and interlukin-1β. Because IFN-γ is not cross-reactive between human and mouse species, the manner in which human MSCs administered in experimental animals are activated and stimulated to function has been questioned. In the present study, we established MSCs from human adipose tissue. They successfully suppressed the proliferation of not only human peripheral blood mononuclear cells but also mouse splenic T cells. When these human MSCs were stimulated with a culture supernatant of mouse T cells or recombinant murine TNF-α, they expressed cyclooxygenase-2 (COX-2), but not indoleamine 2,3-dioxygenase. The dominant role of COX-2 in suppressing mouse T cell proliferation was validated by the addition of COX-2 inhibitor in the co-culture, wherein the suppressed proliferation was almost completely recovered. In conclusion, human MSCs in a murine environment were activated, at least in part, by TNF-α and mainly used COX-2 as a tool for the suppression of in vitro T cell proliferation. These results should be considered when interpreting results for human MSCs in experimental animals.

Recent advances in mesenchymal stem cell immunomodulation: the role of microvesicles

Mesenchymal stem cells are the most widely used cell phenotype for therapeutic applications, the main reasons being their well-established abilities to promote regeneration of injured tissues and to modulate immune responses. Efficacy was reported in the treatment of several animal models of inflammatory and autoimmune diseases and, in clinical settings, for the management of disorders such as GVHD, systemic lupus erythematosus, multiple sclerosis, and inflammatory bowel disease. The effects of mesenchymal stem cells are believed to be largely mediated by paracrine signals, and several secreted molecules have been identified as contributors to the net biological effect. Recently, it has been recognized that bioactive molecules can be shuttled from cell to cell packed in microvesicles, tiny portions of cytoplasm surrounded by a membrane. Coding and noncoding RNAs are also carried in such microvesicles, transferring relevant biological activity to target cells. Several reports indicate that the regenerative effect of mesenchymal stem cells can be reproduced by microvesicles isolated from their culture medium. More recent evidence suggests that the immunomodulatory effects of mesenchymal stem cells are also at least partially mediated by secreted microvesicles. These findings allow better understanding of the mechanisms involved in cell-to-cell interaction and may have interesting implications for the development of novel therapeutic tools in place of the parent cells.

Human umbilical cord-derived mesenchymal stem cells downregulate inflammatory responses by shifting the Treg/Th17 profile in experimental colitis

BACKGROUND/AIMS

The aim of this study was to evaluate the effect and mechanisms of human umbilical cord-derived mesenchymal stem cells (hUC-MSCs) on immune responses in murine colitis.

METHODS

Mice with dextran sulfate sodium (DSS)-induced colitis were injected intraperitoneally with hUC-MSCs or human bone marrow-derived MSCs. The cytokine levels from lamina propria mononuclear cells (LPMCs) and colon tissue were measured using ELISA. Treg and Th17 cells were analyzed using flow cytometry. The proliferation of LPMCs was assessed using Cell Counting Kit-8.

RESULTS

hUC-MSCs ameliorate DSS-induced colitis via the downregulation of colon inflammatory responses. Furthermore, hUC-MSCs adjusted modulation of Treg/Th17 cells in the spleen and mesenteric lymph nodes. hUC-MSCs also inhibited LPMCs in vitro.

CONCLUSION

hUC-MSCs may be an alternative source of stem cells and are worthy of study in long-term clinical trials.

New approaches for the treatment of lupus nephritis in the 21st century: from the laboratory to the clinic

Systemic lupus erythematosus is a complex autoimmune disorder affecting multiple organ systems. Glomerulonephritis leading to severe proteinuria, chronic renal failure and end-stage renal disease remains one of the most severe complications of systemic lupus erythematosus and is associated with significant morbidity and mortality. Conventional lupus nephritis (LN) treatment based on cyclophosphamide, steroids and, recently, mycophenolatemofetil has improved the outcome of the disease over the last 50 years, although failure to achieve remission or treatment resistance has been reported in 18–57% of patients. Chronic complications such as long-term toxicity dampen their ability to maintain disease remission. There is a need to develop more specific pharmacological agents for patients to provide choices that are equally effective, less toxic and have fewer complications. During the last 10 years, experimental studies based on different pathogenesis pathways of LN have provided an enormous amount of knowledge and have offered the possibility to target the disease with selective approaches. In this article, we summarize the new experimental strategies that have recently been utilized to target LN, focusing on mechanisms of action.

p53/p21 Pathway involved in mediating cellular senescence of bone marrow-derived mesenchymal stem cells from systemic lupus erythematosus patients

Our and other groups have found that bone marrow-derived mesenchymal stem cells (BM-MSCs) from systemic lupus erythematosus (SLE) patients exhibited senescent behavior and are involved in the pathogenesis of SLE. Numerous studies have shown that activation of the p53/p21 pathway inhibits the proliferation of BM-MSCs. The aim of this study was to determine whether p53/p21 pathway is involved in regulating the aging of BM-MSCs from SLE patients and the underlying mechanisms. We further confirmed that BM-MSCs from SLE patients showed characteristics of senescence. The expressions of p53 and p21 were significantly increased, whereas levels of Cyclin E, cyclin-dependent kinase-2, and phosphorylation of retinoblastoma protein were decreased in the BM-MSCs from SLE patients and knockdown of p21 expression reversed the senescent features of BM-MSCs from SLE patients. Our results demonstrated that p53/p21 pathway played an important role in the senescence process of BM-MSCs from SLE.

Could mesenchymal stromal cells have a role in childhood autoimmune diseases?

Mesenchymal stromal cells (MSCs) comprise a promising source for cellular therapy due to their ability to be readily isolated from various tissues and expand ex vivo. A unique property of these cells is the modulation of immune responses, making them attractive candidates for the treatment of autoimmune diseases. Recently, several clinical trials, mainly in adults, suggest the use of MSCs for therapy of refractory autoimmune diseases. There are a very limited number of reports in the literature addressing the cellular therapy options for pediatric patients with autoimmune diseases refractory to standard therapy. This review discusses the possible mechanisms underlying the immunosuppressive effects of MSCs on almost all cell types, and also the recent advances in cellular therapy of autoimmune diseases using MSCs as modulators of immune response, especially in children.

Immune therapeutic potential of stem cells from human supernumerary teeth

Discoveries of immunomodulatory functions in mesenchymal stem cells (MSCs) have suggested that they might have therapeutic utility in treating immune diseases. Recently, a novel MSC population was identified from dental pulp of human supernumerary teeth, and its multipotency characterized. Herein, we first examined the in vitro and in vivo immunomodulatory functions of human supernumerary tooth-derived stem cells (SNTSCs). SNTSCs suppressed not only the viability of T-cells, but also the differentiation of interleukin 17 (IL-17)-secreting helper T (Th17)-cells in in vitro co-culture experiments. In addition, systemic SNTSC transplantation ameliorated the shortened lifespan and elevated serum autoantibodies and nephritis-like renal dysfunction in systemic lupus erythematosus (SLE) model MRL/lpr mice. SNTSC transplantation also suppressed in vivo increased levels of peripheral Th17 cells and IL-17, as well as ex vivo differentiation of Th17 cells in MRL/lpr mice. Adoptive transfer experiments demonstrated that SNTSC-transplanted MRL/lpr mouse-derived T-cell-adopted immunocompromised mice showed a longer lifespan in comparison with non-transplanted MRL/lpr mouse-derived T-cell-adopted immunocompromised mice, indicating that SNTSC transplantation suppresses the hyper-immune condition of MRL/lpr mice through suppressing T-cells. Analysis of these data suggests that SNTSCs are a promising MSC source for cell-based therapy for immune diseases such as SLE.

Allogeneic mesenchymal stem cell transplantation in severe and refractory systemic lupus erythematosus: 4 years of experience

Mesenchymal stem cells (MSCs) are multipotential nonhematopoietic progenitors and are capable of differentiating into several tissues of mesenchymal origin. We have shown that bone marrow-derived MSCs from both SLE patients and lupus-prone MRL/lpr mice are defective structurally and functionally. Here we observe the long-term safety and efficacy of allogeneic MSC transplantation (MSCT) in treatment-resistant SLE patients. Eighty-seven patients with persistently active SLE who were refractory to standard treatment or had life-threatening visceral involvement were enrolled. Allogeneic bone marrow or umbilical cord-derived MSCs were harvested and infused intravenously (1 × 10(6) cells/kg of body weight). Primary outcomes were rates of survival, disease remission and relapse, as well as transplantation-related adverse events. Secondary outcomes included SLE disease activity index (SLEDAI) and serologic features. During the 4-year follow-up and with a mean follow-up period of 27 months, the overall rate of survival was 94% (82/87). Complete clinical remission rate was 28% at 1 year (23/83), 31% at 2 years (12/39), 42% at 3 years (5/12), and 50% at 4 years (3/6). Rates of relapse were 12% (10/83) at 1 year, 18% (7/39) at 2 years, 17% (2/12) at 3 years, and 17% (1/6) at 4 years. The overall rate of relapse was 23% (20/87). Disease activity declined as revealed by significant changes in the SLEDAI score, levels of serum autoantibodies, albumin, and complements. A total of five patients (6%) died after MSCT from non-treatment-related events in the 4-year follow-up, and no transplantation-related adverse event was observed. Allogeneic MSCT resulted in the induction of clinical remission and improvement in organ dysfunction in drug-resistant SLE patients.

Allogeneic mesenchymal stem cell treatment alleviates experimental and clinical Sjögren syndrome

Sjögren syndrome (SS) is a systemic autoimmune disease characterized by dry mouth and eyes, and the cellular and molecular mechanisms for its pathogenesis are complex. Here we reveal, for the first time, that bone marrow mesenchymal stem cells in SS-like NOD/Ltj mice and human patients were defective in immunoregulatory functions. Importantly, treatment with mesenchymal stem cells (MSCs) suppressed autoimmunity and restored salivary gland secretory function in both mouse models and SS patients. MSC treatment directed T cells toward Treg and Th2, while suppressing Th17 and Tfh responses, and alleviated disease symptoms. Infused MSCs migrated toward the inflammatory regions in a stromal cell-derived factor-1-dependent manner, as neutralization of stromal cell-derived factor-1 ligand CXCR4 abolished the effectiveness of bone marrow mesenchymal stem cell treatment. Collectively, our study suggests that immunologic regulatory functions of MSCs play an important role in SS pathogenesis, and allogeneic MSC treatment may provide a novel, effective, and safe therapy for patients with SS.

Allogeneic transplantation of umbilical cord-derived mesenchymal stem cells for diffuse alveolar hemorrhage in systemic lupus erythematosus

Umbilical cord-derived mesenchymal stem cell transplantation (UC-MSCT) has been proved to be effective in the treatment of systemic lupus erythematosus (SLE), based on animal experiments and clinical trials. Diffuse alveolar hemorrhage (DAH) is a rare complication of SLE with a high mortality usually over 50%. This study aimed to assess the efficacy of UC-MSCT in the treatment of SLE-associated DAH. Four SLE patients complicated with DAH, who underwent UC-MSCT, were included. Clinical changes before and after transplantation were assessed by measurements of hemoglobin, platelet level, oxygen saturation, and serological factors. High-resolution CT (HRCT) scans of the chest were performed to evaluate pulmonary manifestation. All the four patients showed dramatic improvements of their clinical manifestations. Hemoglobin was elevated after UC-MSCT and was sustained at a normal level 6 months after UC-MSCT in the four patients. Platelet level was upregulated in two patients who had thrombocytopenia at baseline. Oxygen saturation appeared to be normal at 1 month after UC-MSCT, and this result was confirmed by the HRCT scan of the chest. Serum albumin elevated to 3.5 g/dl 6 months after transplantation. Our findings suggest that UC-MSCT results in amelioration of oxygen saturation as well as hematological and serologic changes, which revealed that UC-MSCT could be applied as a salvage strategy for DAH patients.

Upregulation of p16INK4A promotes cellular senescence of bone marrow-derived mesenchymal stem cells from systemic lupus erythematosus patients

Previous studies have indicated that bone marrow-derived mesenchymal stem cells (MSCs) from patients with systemic lupus erythematosus (SLE) exhibited impaired proliferation, differentiation, and immune modulation capacities. Thus, MSCs may be associated with the pathogenesis of SLE. The aim of this study was to determine whether MSCs from SLE patients were senescent and to determine the mechanism underlying this phenomenon. MSCs from both untreated and treated SLE patients showed characteristics of senescence. The expression of p16(INK4A) was significantly increased, whereas levels of CDK4, CDK6 and p-Rb expression were decreased in the MSCs from both untreated and treated SLE patients. Knockdown of p16(INK4A) expression reversed the senescent features of MSCs and upregulated TGF-β expression. In vitro, when purified CD4+ T cells were incubated with p16(INK4A)-silenced SLE MSCs, the percentage of regulatory T cells was significantly increased. Further, we have found that p16(INK4A) promotes MSC senescence via the suppression of the extracellular signal regulated kinase (ERK) pathway. p16(INK4A) knockdown up-regulated ERK1/2 activation. Our results demonstrated that MSCs from SLE patients were senescent and that p16 (INK4A) plays an essential role in the process by inhibiting ERK1/2 activation.

Double allogenic mesenchymal stem cells transplantations could not enhance therapeutic effect compared with single transplantation in systemic lupus erythematosus

The clinical trial of allogenic mesenchymal stem cells (MSCs) transplantation for refractory SLE patients has shown significant safety and efficacy profiles. However, the optimum frequency of the MSCs transplantation (MSCT) is unknown. This study was undertaken to observe whether double transplantations of MSCs is superior to single transplantation. Fifty-eight refractory SLE patients were enrolled in this study, in which 30 were randomly given single MSCT, and the other 28 were given double MSCT. Patients were followed up for rates of survival, disease remission, and relapse, as well as transplantation-related adverse events. SLE disease activity index (SLEDAI) and serologic features were evaluated. Our results showed that no remarkable differences between single and double allogenic MSCT were found in terms of disease remission and relapse, amelioration of disease activity, and serum indexes in an SLE clinical trial with more than one year followup. This study demonstrated that single MSCs transplantation at the dose of one million MSCs per kilogram of body weight was sufficient to induce disease remission for refractory SLE patients.

Aire controls mesenchymal stem cell-mediated suppression in chronic colitis

Mesenchymal stem cells (MSCs) are emerging as a promising immunotherapeutic, based largely on their overt suppression of T lymphocytes under inflammatory and autoimmune conditions. While paracrine cross-talk between MSCs and T cells has been well-studied, an intrinsic transcriptional switch that programs MSCs for immunomodulation has remained undefined. Here we show that bone marrow-derived MSCs require the transcriptional regulator Aire to suppress T cell-mediated pathogenesis in a mouse model of chronic colitis. Surprisingly, Aire did not control MSC suppression of T cell proliferation in vitro. Instead, Aire reduced T cell mitochondrial reductase by negatively regulating a proinflammatory cytokine, early T cell activation factor (Eta)-1. Neutralization of Eta-1 enabled Aire(-/-) MSCs to ameliorate colitis, reducing the number of infiltrating effector T cells in the colon, and normalizing T cell reductase levels. We propose that Aire represents an early molecular switch imposing a suppressive MSC phenotype via regulation of Eta-1. Monitoring Aire expression in MSCs may thus be a critical parameter for clinical use.

A toxicity study of multiple-administration human umbilical cord mesenchymal stem cells in cynomolgus monkeys

Therapies based on stem cells have shown very attractive potential in many clinical studies. However, the data about the safety of stem cells application remains insufficient. The present study was designed to evaluate the overall toxicology of human umbilical cord mesenchymal stem cells (hUC-MSCs) in cynomolgus monkeys with repeated administrations. hUC-MSCs were administered by intravenous injection once every 2 weeks for 6 weeks. The dose levels employed in this study were 2×10(6), 1×10(7) cells/kg body weight. Toxicity was evaluated by clinical observations (body weight, body temperature, and ophthalmology exams), pathology (blood cell counts, clinical biochemistry, urinalysis, and bone marrow smears), immunologic consequences (lymphoproliferation assay, the secretion of interferon-γ and interleukin-4, the percentage of CD3, CD4, CD8 T cells, and the ratio of CD4 and CD8 T cells) and anatomic pathology. Pharmacodynamics in blood and distribution of hUC-MSCs in the tissues of cynomolgus monkeys were measured by real-time polymerase chain reaction. All animals survived until scheduled euthanasia. No stem cells transplantation-related toxicity was found in this study. hUC-MSCs could be found in the blood of cynomolgus monkeys beyond 8 h. The findings of this 6-week toxicity study showed that the transplantation of hUC-MSCs did not affect the general health of cynomolgus monkeys.

Efficacy of allogeneic mesenchymal stem cell transplantation in patients with drug-resistant polymyositis and dermatomyositis

OBJECTIVE

To assess the safety and clinical efficacy of allogeneic mesenchymal stem cell transplantation (MSCT) in a small-scale pilot study with 10 patients with drug-resistant polymyositis (PM) or dermatomyositis (DM).

METHODS

A single-arm trial involving 10 patients with DM/PM who were either refractory to standard treatment, or had severe systemic involvement. All patients consented and underwent allogeneic MSCT. Clinical and laboratory manifestations were compared before and after MSCT.

RESULTS

Improvements were seen in serum creatine kinase (CK), CK-MB, patient global assessment by visual analogue scale and muscle strength by manual muscle test in all patients, as well as improvement in interstitial lung disease in selected patients. Improvement in chronic non-healing skin ulcers was noted in one patient. Clinical responses were also seen in patients undergoing a second MSCT for recurrence of disease.

CONCLUSION

MSCT appears safe and effective in drug-resistant patients with DM/PM. Larger-scale studies including a control group receiving standard treatment are needed to assess the long-term efficacy of allogeneic MSCT in refractory patients with DM/PM.

Mesenchymal stem cells for the treatment of systemic lupus erythematosus: is the cure for connective tissue diseases within connective tissue?

Mesenchymal stem cells (MSCs) are now known to display not only adult stem cell multipotency but also robust anti-inflammatory and regenerative properties. After widespread in vitro and in vivo preclinical testing in several autoimmune disease models, allogenic MSCs have been successfully applied in patients with severe treatment-refractory systemic lupus erythematosus. The impressive results of these uncontrolled phase I and II trials - mostly in patients with non-responding renal disease - point to the need to perform controlled multicentric trials. In addition, they suggest that there is much to be learned from the basic and clinical science of MSCs in order to reap the full potential of these multifaceted progenitor cells in the treatment of autoimmune diseases.

Murine models of systemic lupus erythematosus

Systemic lupus erythematosus (SLE) is a multifactorial autoimmune disorder. The study of diverse mouse models of lupus has provided clues to the etiology of SLE. Spontaneous mouse models of lupus have led to identification of numerous susceptibility loci from which several candidate genes have emerged. Meanwhile, induced models of lupus have provided insight into the role of environmental factors in lupus pathogenesis as well as provided a better understanding of cellular mechanisms involved in the onset and progression of disease. The SLE-like phenotypes present in these models have also served to screen numerous potential SLE therapies. Due to the complex nature of SLE, it is necessary to understand the effect specific targeted therapies have on immune homeostasis. Furthermore, knowledge gained from mouse models will provide novel therapy targets for the treatment of SLE.

Why should mesenchymal stem cells (MSCs) cure autoimmune diseases?

The adult stem/progenitor cells from bone marrow and other tissues referred to as mesenchymal stem cells or multipotent mesenchymal stromal cells (MSCs) display a significant therapeutic plasticity as reflected by their ability to enhance tissue repair and influence the immune response both in vitro and in vivo. In this review we will focus on the paradigmatic preclinical experience achieved testing MSCs in experimental autoimmune encephalomyelitis (EAE), a model for multiple sclerosis. We will emphasize how the paradigm changed over time from the original prediction that MSCs would enhance tissue repair through their transdifferentiation into somatic cells to the current paradigm that they can produce therapeutic benefits without engraftment into the injured tissues. The data will be reviewed in terms of the potentials of MSCs for therapy of autoimmune diseases.