Autologous hemopoietic stem cell transplantation: a possible cure for rheumatoid arthritis?

The tripartite motif-containing protein 3 on the proliferation and cytokine secretion of rheumatoid arthritis fibroblast-like synoviocytes

Recent studies have revealed fibroblast-like synoviocytes (FLS) as a pivotal effector cell in the inflamed joint of rheumatoid arthritis (RA) patients. FLS exhibit high proliferation rates and constitutive expression of cytokines, contributing to the pathogenesis of RA. In this study, we found that the expression of tripartite motif-containing protein 3 (TRIM3), a candidate tumor suppressor gene, was lower in synovial tissue samples of RA patients than in that of healthy controls. We then investigated the role of TRIM3 on the proliferation and cytokine secretion of primary cultured FLS from RA patients. Enforced expression of TRIM3 in RA FLS led to significantly decreased cell proliferation as indicated by Cell Counting Kit-8 assay, reduced secretion of tumor necrosis factor-α (TNF)-α, interleukin (IL)-1β and IL-6 as indicated by enzyme-linked immunosorbent assays, and decreased p38 phosphorylation as assessed by western blot analysis. The proteins promoting cell cycles (cyclin D1 and PCNA) were downregulated and the protein negatively regulating cell cycle progression (p53 and p21) was upregulated after TRIM3 overexpression. Importantly, TRIM3 knockdown had reverse effects on cell proliferation, which was suppressed by the p38-specific inhibitor SB203580. In conclusion, the current results demonstrated the downregulation of TRIM3 expression in RA synovial tissues. Importantly, TRIM3 exerted an anti-proliferation role in RA FLS via p38 signaling pathway.

MicroRNA-124 inhibits the progression of adjuvant-induced arthritis in rats

Objective

MicroRNAs (miRNAs) are small endogenous, non-coding RNAs that act as post-transcriptional regulators. We analysed the in vivo effect of miRNA-124 (miR-124, the rat analogue of human miR-124a) on adjuvant-induced arthritis (AIA) in rats.

Methods

AIA was induced in Lewis rats by injecting incomplete Freund's adjuvant with heat-killed Mycobacterium tuberculosis. Precursor (pre)-miR-124 was injected into the right hind ankle on day 9. Morphological changes in the ankle joint were assessed by micro-CT and histopathology. Cytokine expression was examined by western blotting and real-time RT-PCR. The effect of miR-124 on predicted target messenger RNAs (mRNAs) was examined by luciferase reporter assays. The effect of pre-miR-124 or pre-miR-124a on the differentiation of human osteoclasts was examined by tartrate-resistant acid phosphatase staining.

Results

We found that miR-124 suppressed AIA in rats, as demonstrated by decreased synoviocyte proliferation, leucocyte infiltration and cartilage or bone destruction. Osteoclast counts and expression level of receptor activator of the nuclear factor κB ligand (RANKL), integrin β1 (ITGB1) and nuclear factor of activated T cells cytoplasmic 1 (NFATc1) were reduced in AIA rats treated with pre-miR-124. Luciferase analysis showed that miR-124 directly targeted the 3′UTR of the rat NFATc1, ITGB1, specificity protein 1 and CCAAT/enhancer-binding protein α mRNAs. Pre-miR-124 also suppressed NFATc1 expression in RAW264.7 cells. Both miR-124 and miR-124a directly targeted the 3′-UTR of human NFATc1 mRNA, and both pre-miR-124 and pre-miR-124a suppressed the differentiation of human osteoclasts.

Conclusions

We found that miR-124 ameliorated AIA by suppressing critical prerequisites for arthritis development, such as RANKL and NFATc1. Thus, miR-124a is a candidate for therapeutic use for human rheumatoid arthritis.

Comparative tolerability of treatments for juvenile idiopathic arthritis

Juvenile idiopathic arthritis (JIA) includes several forms of chronic arthritis in children. Treatments are chosen according to the type and severity of the disease. Nonsteroidal anti-inflammatory drugs (NSAIDs) and corticosteroids remain the mainstays of therapy. Traditional slower acting anti-rheumatic drugs, such as gold therapy, penicillamine, sulfasalazine, tiopronin and hydroxychloroquine, are usually poorly active in children. In addition, adverse effects are common, including severe macrophage activation syndrome with gold therapy or sulfasalazine. Low dose, once weekly methotrexate has emerged as the therapeutic agent of choice for children who fail to respond adequately to the administration of an NSAID, especially in those with the extended oligoarticular subtype of the disease. Other immunosuppressive agents, such as cyclosporin, are sometimes combined with methotrexate. In recent years, novel treatments have been developed. Autologous hematopoietic stem cell transplantation is effective in a number of children with severe JIA, whose disease has been refractory to conventional therapy. However, only short term follow-up data are currently available for this novel therapy. In addition, severe infections complicated by macrophage activation syndrome and death have been reported. Finally, anti-tumour necrosis factor-alpha therapy has shown efficacy in more than two-thirds of children with JIA and polyarthritis, and other cytokine inhibitors may be soon available.

MicroRNA-124a is a key regulator of proliferation and monocyte chemoattractant protein 1 secretion in fibroblast-like synoviocytes from patients with rheumatoid arthritis

OBJECTIVE

To elucidate the role of microRNA (miRNA) in the pathogenesis of rheumatoid arthritis (RA), we analyzed synoviocytes from RA patients for their miRNA expression.

METHODS

Synoviocytes derived from surgical specimens obtained from RA patients were compared with those obtained from osteoarthritis (OA) patients for their expression of a panel of 156 miRNA with quantitative stem-loop reverse transcription-polymerase chain reaction. The miRNA whose expression decreased or increased in RA synoviocytes as compared with OA synoviocytes were identified, and their target genes were predicted by computer analysis. We used an in vitro system of enhancing the expression of specific miRNA by transfection of precursors into synoviocytes, and then we performed proliferation, cell cycle, and apoptosis assays, as well as enzyme-linked immunosorbent assays for cytokine production. The effects of transfection on predicted target protein and messenger RNA (mRNA) were then examined by Western blot analysis and luciferase reporter assay.

RESULTS

We found that miR-124a levels significantly decreased in RA synoviocytes as compared with OA synoviocytes. Transfection of precursor miR-124a into RA synoviocytes significantly suppressed their proliferation and arrested the cell cycle at the G1 phase. We identified a putative consensus site for miR-124a binding in the 3'-untranslated region of cyclin-dependent kinase 2 (CDK-2) and monocyte chemoattractant protein 1 (MCP-1) mRNA. Induction of miR-124a in RA synoviocytes significantly suppressed the production of the CDK-2 and MCP-1 proteins. Luciferase reporter assay demonstrated that miR-124a specifically suppressed the reporter activity driven by the 3'-untranslated regions of CDK-2 and MCP-1 mRNA.

CONCLUSION

The results of this study suggest that miR-124a is a key miRNA in the posttranscriptional regulatory mechanisms of RA synoviocytes.

Induction of allogenic T-cell hyporesponsiveness by galectin-1-mediated apoptotic and non-apoptotic mechanisms

Galectin-1, a beta-galactoside-binding protein expressed at sites of T-cell activation and immune privilege, has shown specific immunosuppressive properties. Because of the implications of this protein in T-cell tolerance and its potential use to avoid graft rejection, we investigated the immunosuppressive effects of galectin-1 in the course of the human allogenic T-cell response. Galectin-1 induced a dose- and carbohydrate-dependent inhibition of the allogenic T-cell response. Addition of galectin-1 to alloreactive lymphocytes resulted in significant apoptosis of CD45R0-positive cells. This negative regulatory effect was accompanied by caspase activation, Bcl-2 downregulation and was prevented by addition of exogenous IL-2. In addition, a significant decrease of IFN-gamma production was detected in the non-apoptotic cell population, following exposure of alloreactive lymphocytes to galectin-1. Moreover, the immunosuppressive activity of this protein did not involve TGF-beta-mediated mechanisms. Since galectin-1 is expressed by activated T cells and could be acting by an autocrine negative loop to control human T-cell reactivity, we finally examined the regulated expression of this protein throughout the allogenic T-cell response. Expression of endogenous galectin-1 was detected at 24 h of cell culture, reaching its maximal levels after 72 h of allostimulation. The present study sets the basis for a potential use of galectin-1 as a selective immunosuppressive agent to limit T-cell-mediated reactivity during the effector phase of the alloimmune response.

2-Chloroadenosine but not adenosine induces apoptosis in rheumatoid fibroblasts independently of cell surface adenosine receptor signalling

1. The apoptotic effect of adenosine and its analogues was studied in fibroblast-like synoviocytes derived from rheumatoid arthritis patients (RA-FLSs). Evoked cell death was quantitatively examined by assessing DNA fragmentation using an enzyme-liked immunosorbent assay and by measuring phosphatidylserine exposure through flow cytometric analysis of annexin V binding. 2. Exposing cells for 24 h to 2-chloroadenosine (2-CADO), a nonspecific, adenosine deaminase (ADA)-resistant, adenosine receptor (AdoR) agonist, induced DNA fragmentation, and thus apoptosis, in RA-FLSs at concentrations > or =50 microM. By contrast, incubation with adenosine for up to 72 h did not evoke DNA fragmentation, even in the presence of ADA inhibitor coformycin and nucleoside transporter inhibitor nitrobenzylmercaptopurin (NBMPR). Transcription of all four AdoR isoforms was detected in RA-FLSs; nevertheless selective AdoR agonists similarly failed to induce DNA fragmentation. 3. DNA fragmentation evoked by 2-CADO was inhibited by NBMPR and by 5'-iodotubercidin, an adenosine kinase inhibitor, but not by xanthine amine congener, an A(1) and A(2) receptor antagonist, or by selective AdoR antagonists. 4. The nonspecific caspase inhibitor benzyloxycarbonyl-Val-Ala-Asp fluoromethyl ketone abolished the apoptotic effect of 2-CADO. 5. These results suggest that 2-CADO induces apoptosis in RA-FLSs independently of AdoR-mediated signalling. Instead, 2-CADO, but not adenosine, is taken up into RA-FLSs via human equilibrative nucleoside transporter-1, where it is phosphorylated by adenosine kinase. The resultant phospho-2-CADO induces DNA fragmentation by activating a caspase pathway.

Immune ablation and stem-cell therapy in autoimmune disease. Immunological reconstitution after high-dose immunosuppression and haematopoietic stem-cell transplantation

Studies on immunological reconstitution after immune ablation and stem-cell therapy may yield important clues to our understanding of the pathogenesis of human autoimmune disease, due to the profound effects of function and organization of the immune system. Such studies are also indispensable when linking clinical sequelae such as opportunistic infections to the state of immune deficiency that ensues after the treatment. Much has been learnt on these issues from comparable studies in haemato-oncological diseases, although it remains to be proven that the data obtained from these studies can be extrapolated to rheumatological autoimmune diseases. Preliminary results from pilot studies in various rheumatological conditions not only pointed to clinical efficacy of the new treatment modality but also unveiled marked effects on T-cell receptor repertoires of circulating T lymphocytes, on titres of autoantibodies and T- and B-cell subsets.

Macrophages in rheumatoid arthritis

The abundance and activation of macrophages in the inflamed synovial membrane/pannus significantly correlates with the severity of rheumatoid arthritis (RA). Although unlikely to be the 'initiators' of RA (if not as antigen-presenting cells in early disease), macrophages possess widespread pro-inflammatory, destructive, and remodeling capabilities that can critically contribute to acute and chronic disease. Also, activation of the monocytic lineage is not locally restricted, but extends to systemic parts of the mononuclear phagocyte system. Thus, selective counteraction of macrophage activation remains an efficacious approach to diminish local and systemic inflammation, as well as to prevent irreversible joint damage.

Recombinant galectin-1 and its genetic delivery suppress collagen-induced arthritis via T cell apoptosis

Galectin-1 (GAL-1), a member of a family of conserved beta-galactoside-binding proteins, has been shown to induce in vitro apoptosis of activated T cells and immature thymocytes. We assessed the therapeutic effects and mechanisms of action of delivery of GAL-1 in a collagen-induced arthritis model. A single injection of syngeneic DBA/1 fibroblasts engineered to secrete GAL-1 at the day of disease onset was able to abrogate clinical and histopathological manifestations of arthritis. This effect was reproduced by daily administration of recombinant GAL-1. GAL-1 treatment resulted in reduction in anticollagen immunoglobulin (Ig)G levels. The cytokine profile in draining lymph node cells and the anticollagen IgG isotypes in mice sera at the end of the treatment clearly showed inhibition of the proinflammatory response and skewing towards a type 2-polarized immune reaction. Lymph node cells from mice engaged in the gene therapy protocol increased their susceptibility to antigen-induced apoptosis. Moreover, GAL-1-expressing fibroblasts and recombinant GAL-1 revealed a specific dose-dependent inhibitory effect in vitro in antigen-dependent interleukin 2 production to an A(q)-restricted, collagen type 2-specific T cell hybridoma clone. Thus, a correlation between the apoptotic properties of GAL-1 in vitro and its immunomodulatory properties in vivo supports its therapeutic potential in the treatment of T helper cell type 1-mediated autoimmune disorders.

Haematopoietic stem cell transplantation for active systemic lupus erythematosus

OBJECTIVE

For patients with systemic lupus erythematosus (SLE) who are at risk of disease-related mortality, we have initiated a protocol of intensive immunosuppression and haematopoietic stem cell support. The first patient enrolled in this study was in the midst of a lupus flare manifest by nephritis and rapidly declining renal function, uncontrolled hypertension, immune-mediated cytopenias, and serositis characterized by a large pericardial effusion and abdominal pain. Antinuclear antibody (ANA), anti-double-stranded (ds) DNA and complement were abnormal. This patient is now more than 1 yr post-stem cell transplant and is taking no immunosuppressive medication. Her serologies are normal, effusions have resolved, blood pressure is normal and renal function is markedly improved. The clinical and serological course of this patient is summarized here.

METHODS

Autologous haematopoietic stem cells (HSC) were mobilized with cyclophosphamide (2.0 g/m2) and granulocyte colony-stimulating factor (G-CSF) (10 microg/kg/day). Stem cells were enriched ex vivo using CD34-positive immunoselection and reinfused after immunosuppression with cyclophosphamide (200 mg/kg) and antithymocyte globulin (ATG) (90 mg/kg).

RESULTS

White blood cell engraftment with an absolute neutrophil count (ANC) of >500/microl (0.5 x 10(9)/l) and platelet engraftment with a non-transfused platelet count of >20000/microl (20 x 10(9)/l) occurred on day 10 and 14, respectively. Therapy was complicated by a cell lysis-like effect with hyperphosphataemia, hyperuricaemia, normal anion gap metabolic acidosis and transient exacerbation of renal insufficiency.

CONCLUSION

This is the first autologous T-cell-depleted haematopoietic stem cell transplantation performed to treat lupus in an active flare. This patient has, for the first time since discase onset (13 yr ago), entered a complete clinical and serological remission which persists at >1 yr of follow-up. The durability of this remission is unknown.

Stem cell transplantation--a treatment for severe rheumatic diseases?--A review

Rheumatic diseases can be severe and unresponsive to standard therapeutic approaches. Preclinical studies and anecdotal case reports suggest that high-dose immunosuppressive therapy supported by stem cell transplantation may lead to remissions or even cure in various experimental disease models of autoimmunity as well as in some human rheumatic diseases. This review attempts to summarize some preclinical and clinical data on stem cell transplantation in the treatment of severe rheumatic diseases. In addition to practical aspects, some future perspectives are also discussed.

Composition and function of peripheral blood stem and progenitor cell harvests from patients with severe active rheumatoid arthritis

High-dose chemotherapy with autologous stem cell rescue has been proposed as an intensive therapy for severe rheumatoid arthritis (RA). In view of previous observations of abnormal haemopoiesis in RA patients, the composition and function of peripheral blood stem cell harvests (PBSCH) was investigated. Compared with PBSCH from healthy allogeneic donors mobilized with the same dose of G-CSF (filgrastim; 10 microg/kg/d, n = 14), RA PBSCH (n = 9) contained significantly fewer mononuclear cells (375 v 569 x 10(6)/kg, P = 0.03) and CD34+ cells (2.7 v 5.8 x 10(6)/kg, P = 0.003). However, there were increased proportions of CD14+ cells (P = 0.006) and CD14+ CD15+ cells (the phenotype of previously described 'abnormal' myeloid cells, P = 0.002) in the RA PBSCH which translated into 3.5- and 7-fold increases respectively on a per CD34+ cell basis. There were no differences in T-cell activation status as judged by proportions of CD4+ and CD8+ expressing CD45RA, CD45RO, HLA-DR and CD28 (RA PBSCH, n = 7, donor PBSCH, n = 5, P = 0.2-0.7). Phytohaemagglutinin responses determined fluorocytometrically with induction of CD69 expression were reduced in CD4+ and CD8+ cells following filgrastim administration in 3/3 RA patients tested. Compared with bone marrow as a potential source of CD34+ cells, PBSCH contained 11-fold more T cells (P < 0.0005), 8-fold more B cells (P < 0.0005) and 4-fold more monocytes (P = 0.02). In short-term methylcellulose culture there were no differences in colony counts (CFU-GM, CFU-GEMM, BFU-E) per CD34+ cell from PBSCH from RA patients (n = 11) and healthy donors (n = 10). Long-term culture initiator cells were cultured successfully from cryopreserved PBSCH from RA patients (n = 9). In conclusion, PBSCH from RA patients differed significantly in composition from normal individuals, but in vitro studies support normal stem and progenitor cell function. Changes in T-cell function occur during mobilization in RA patients. This work provides reassurance for the use of PBSCH as haematological rescue and baseline data for clinical trials of graft manipulation strategies in patients with RA.

Immunotherapy for autoimmune and inflammatory renal diseases

New treatments for autoimmune renal disease are required, and a developing knowledge of its underlying immunopathogenesis has identified sites where immunotherapy is likely to be effective. Experience with intravenous immunoglobulin and lymphocyte depletion by monoclonal antibodies in systemic vasculitis and systemic lupus erythematosus is awaiting confirmation by randomized trials. Treatments at or near clinical testing include monoclonal antibody blockade of leucocyte-endothelial interactions and CD40 mediated B-cell activation, and immunoablation with autologous stem-cell transplantation for more severe multisystem autoimmune disease.

Rheumatoid arthritis: current clinical and research directions

Rheumatoid arthritis (RA) is a systemic autoimmune disease characterized by synovitis and joint erosions. It affects approximately 1% of the adult population in a female/male ratio ranging from 2:1 to 4:1. RA is an insidious disease, typically having an onset of symmetric joint swelling and reaching a peak incidence in the fourth and fifth decades. Extraarticular manifestations include pulmonary, ocular, and vascular disease. The etiology of RA remains unknown. Attempts to discover infectious causes have proven unsuccessful, although environmental influences may trigger a response leading to the development of this autoimmune disease. Genetic associations have been identified, particularly with the major histocompatibility complex class II antigens. Furthermore, twin studies have shown a 30%-50% concordance rate for monozygotic twins. Approximately 70%-80% of patients with RA have rheumatoid factor present in the blood, although its role remains unclear. Hormonal status may influence RA. The majority of RA patients are women, and in 75% of them, the disease improves during pregnancy. RA has significant financial and social implications associated with treatment costs, lost wages, disability, and increased mortality. Mainstays of medical therapy have included nonsteroidal anti-inflammatory and immunosuppressive agents, such as prednisone and methotrexate. Recent advances in the treatment of RA include specific inhibitors of cyclooxygenase II, T cells, blood vessels, cytokines (such as tumor necrosis factor-alpha [TNF-alpha] or interleukin-1 [IL-1]), and adhesion molecules. Additional studies are ongoing with combination interventions. It is anticipated that a better understanding of the basic pathophysiologic mechanisms critical in RA pathogenesis will provide more precise and efficacious therapy.

Outcome of rheumatoid arthritis and psoriasis following autologous stem cell transplantation for hematologic malignancy

Based on successful results in animal models, it has been proposed that high-dose myeloablative therapy followed by autologous bone marrow or stem cell transplantation (ABMT/ASCT) may cure autoimmune disease. The coexistence of autoimmune disease and hematologic malignancy provides an opportunity to examine the response of autoimmune disease to ABMT or ASCT. We describe 4 patients with autoimmune disease (3 with psoriasis and 1 with rheumatoid arthritis) and hematologic malignancy. In each patient, the autoimmune disease remitted posttransplantation, but, in 4 patients with long-term followup, it recurred at 8-24 months. The earliest relapse occurred in a patient treated with interferon-alpha. Our experience suggests that a single autograft with unpurged stem cells is unlikely to cure autoimmune disease, but that other strategies building on this approach are worthy of investigation.