sirolimus and Scleroderma--Systemic

Systemic sclerosis (SSc) is a chronic autoimmune disease characterized by inflammation and fibrosis. Our previous research has indicated that Sirtuin1 (Sirt1) plays a role in the regulation of TNF-α-induced inflammation; however, whether Sirt1 may inhibit the progress of SSc by blocking inflammation remains unknown.. We aimed to investigate the function of Sirt1 in SSc.. The function and its mechanism of Sirt1 were evaluated in fibroblasts or scleroderma mice. The expression of Sirt1 and cytokines was analyzed using real-time PCR, western blot, ELISA and immunohistochemistry.. We determined that fibroblasts of SSc patients were activated to exhibit inflammation. Sirt1, activated by resveratrol (Res), ameliorated cutaneous inflammation and fibrosis in bleomycin (BLM)-induced scleroderma mice. An improvement in mammalian target of rapamycin (mTOR) was identified in the fibroblasts of SSc patients and the skin lesions of BLM mice. Rapamycin, an mTOR specific inhibitor, substantially inhibited the induced inflammation and fibrosis. The enhancement of mTOR expression in the skin lesions of the BLM-treated mice was significantly inhibited by Sirt1 activation. However, in both the BLM-treated cells and mice, Res exerted an inhibitory function on the expression of inflammatory factors, and collagen was diminished following mTOR knockdown. These findings suggest that Res may inhibit inflammation and fibrosis via mTOR.. The modulation of Sirt1 activity may represent a potential therapeutic method for SSc. The mechanism may involve the inhibition of mTOR phosphorylation, whereas mTOR activity was shown to be a pathogenic culprit of SSc.

Topics: Animals; Biopsy; Bleomycin; Cells, Cultured; Collagen; Cytokines; Disease Models, Animal; Enzyme-Linked Immunosorbent Assay; Female; Fibroblasts; Gene Knockdown Techniques; Humans; Immunohistochemistry; Mice; Mice, Inbred C3H; Phosphorylation; Real-Time Polymerase Chain Reaction; Resveratrol; RNA, Messenger; Scleroderma, Systemic; Signal Transduction; Sirolimus; Sirtuin 1; Skin; Stilbenes; TOR Serine-Threonine Kinases; Tumor Necrosis Factor-alpha

Fibrillin-1 (FBN1) deficiency-induced systemic sclerosis is attributed to elevation of interleukin-4 (IL4) and TGF-β, but the mechanism underlying FBN1 deficiency-associated osteopenia is not fully understood. We show that bone marrow mesenchymal stem cells (BMMSCs) from FBN1-deficient (Fbn1(+/-)) mice exhibit decreased osteogenic differentiation and increased adipogenic differentiation. Mechanistically, this lineage alteration is regulated by IL4/IL4Rα-mediated activation of mTOR signaling to down-regulate RUNX2 and up-regulate PPARγ2, respectively, via P70 ribosomal S6 protein kinase (P70S6K). Additionally, we reveal that activation of TGF-β/SMAD3/SP1 signaling results in enhancement of SP1 binding to the IL4Rα promoter to synergistically activate mTOR pathway in Fbn1(+/-) BMMSCs. Blockage of mTOR signaling by osteoblastic-specific knockout or rapamycin treatment rescues osteopenia phenotype in Fbn1(+/-) mice by improving osteogenic differentiation of BMMSCs. Collectively, this study identifies a previously unrecognized role of the FBN1/TGF-β/IL4Rα/mTOR cascade in BMMSC lineage selection and provides experimental evidence that rapamycin treatment may provide an anabolic therapy for osteopenia in Fbn1(+/-) mice.

Topics: Adipogenesis; Animals; Bone Diseases, Metabolic; Cell Differentiation; Cells, Cultured; Female; Fibrillin-1; Fibrillins; Flow Cytometry; Immunoblotting; Immunosuppressive Agents; Male; Mesenchymal Stem Cells; Mice, 129 Strain; Mice, Inbred C57BL; Mice, Knockout; Mice, Transgenic; Microfilament Proteins; Microscopy, Fluorescence; Osteogenesis; Receptors, Cell Surface; RNA Interference; Scleroderma, Systemic; Signal Transduction; Sirolimus; TOR Serine-Threonine Kinases; Transforming Growth Factor beta

Rapamycin has been shown to exert an anti-fibrotic effect on skin fibrosis in a certain subset of patients with systemic sclerosis (SSc) and in bleomycin-treated animal models.. To investigate the mechanism responsible for the anti-fibrotic effect of rapamycin especially by focusing on human α2(I) collagen (COL1A2) and matrix metalloproteinase 1 (MMP1) genes in normal and systemic sclerosis (SSc) dermal fibroblasts.. The expression levels of type I procollagen and MMP1 proteins were analyzed by immunoblotting and the mRNA levels of COL1A2 and MMP1 genes were evaluated by quantitative real-time RT-PCR. The activities of COL1A2 and MMP1 promoters were determined by reporter analysis.. Rapamycin significantly decreased the levels of type I procollagen protein and COL1A2 mRNA, while significantly increasing the levels of MMP1 protein and mRNA in normal dermal fibroblasts. Similar effects of rapamycin were also observed in SSc dermal fibroblasts. Importantly, the inhibitory and stimulatory effects of rapamycin on the mRNA levels of COL1A2 and MMP1 genes, respectively, were significantly greater in SSc dermal fibroblasts than in normal dermal fibroblasts. In SSc dermal fibroblasts, rapamycin affected the expression of COL1A2 gene at the post-transcriptional level. In contrast, rapamycin altered the expression of MMP1 gene at the transcriptional level through the JNK/c-Jun signaling pathway in those cells.. Rapamycin has a potential to directly regulate the deposition of type I collagen in extracellular matrix through inhibiting type I collagen synthesis and promoting its degradation by MMP1, suggesting that this drug is useful for the treatment of SSc.

Topics: Cell Survival; Cells, Cultured; Collagen Type I; Drug Evaluation, Preclinical; Fibroblasts; Gene Expression; Humans; Immunosuppressive Agents; Matrix Metalloproteinase 1; Scleroderma, Systemic; Sirolimus

This retrospective study analyzes 34 patients with severe sclerodermatous chronic graft-versus-host disease (cGVHD) treated with inhibitors of the mammalian target of rapamycin (mTOR-I). Twelve patients received mTOR-I as monotherapy and 22 a combination therapy. Four patients also received extracorporal photopheresis. mTOR-I were applied as first-line therapy (n = 15) or in refractory disease (n = 19). Drug doses were adjusted to low therapeutical levels (3-8 ng/mL). Six and 20 patients had a complete and a partial response, respectively, with an overall response rate of 76%. Two additional patients had stable disease. Six refractory patients required alternative therapy. Comedication, especially steroids, could be tapered and stopped in a significant number of patients. No difference in response was observed in everolimus- and sirolimus-treated patients. Major adverse events possibly related to mTOR-I were hyperlipidemia and impaired wound healing. Two patients developed thrombotic microangiopathy. Eight patients died, 5 of the nonresponders (cGVHD; n = 3, infection; n = 2) and 3 of the responders (relapse of the underlying malignancy; n = 1, secondary malignancy; n = 1, unknown cause; n = 1). Twenty-six of the 34 patients remain alive, 18 still on therapy with mTOR-I. Median follow-up for surviving patients is 723 days (range 88-1621). The overall survival at 3 years since mTOR-I is 72%. In conclusion, mTOR-I seem to be an effective and well-tolerated treatment option for patients with sclerodermatous cGVHD.

Topics: Adolescent; Adult; Combined Modality Therapy; Everolimus; Female; Graft vs Host Disease; Hematopoietic Stem Cell Transplantation; Humans; Immunosuppressive Agents; Male; Middle Aged; Photopheresis; Protein Kinase Inhibitors; Recurrence; Retrospective Studies; Scleroderma, Systemic; Sirolimus; Steroids; Survival Analysis; TOR Serine-Threonine Kinases; Transplantation, Homologous; Treatment Outcome; Young Adult

Rapamycin, a novel macrolide immunosuppressive drug, is increasingly used as an agent for posttransplant immunosuppression and treatment of autoimmune disease. The molecular mechanism related to rapamycin-mediated immunosuppression is that rapamycin binds to FK-506 binding protein 12, and the formed complex inhibits the function of the mammalian target of rapamycin (mTOR), which in turn reduces protein phosphorylation, cell cycle progression, and cytokine production. The aim of this study was to examine the effect of rapamycin against the development of fibrosis and autoimmunity in 2 different types of systemic sclerosis (SSc) model mice.. Tight skin (TSK/+) mice and bleomycin- induced SSc model mice were used to evaluate the effect of rapamycin on fibrosis and immunologic abnormalities. Furthermore, the antifibrotic effect of rapamycin was assessed using TSK/+ mouse fibroblasts.. Treatment with rapamycin reduced skin fibrosis of TSK/+ mice and skin and lung fibrosis of bleomycin-induced SSc model mice. The production of fibrogenic cytokines, such as interleukin-4 (IL-4), IL-6, IL-17, and transforming growth factor beta1, was attenuated by rapamycin. Hypergammaglobulinemia and anti-topoisomerase I antibody production were also reduced by rapamycin treatment in TSK/+ mice. In addition, mTOR expression levels were increased in TSK/+ mouse fibroblasts compared with those in wild-type mouse fibroblasts. Rapamycin treatment inhibited proliferation and collagen production of TSK/+ mouse fibroblasts in a dose-dependent manner.. This study is the first to show that rapamycin has a significant inhibitory effect on fibrosis in both TSK/+ and bleomycin-induced SSc model mice. These results suggest that rapamycin might be an attractive candidate for clinical trials in SSc patients.

Topics: Animals; Cell Proliferation; Cytokines; Disease Models, Animal; Dose-Response Relationship, Drug; Enzyme-Linked Immunosorbent Assay; Fibroblasts; Fibrosis; Immunohistochemistry; Immunosuppressive Agents; Intracellular Signaling Peptides and Proteins; Lung; Mice; Mice, Transgenic; Protein Serine-Threonine Kinases; Reverse Transcriptase Polymerase Chain Reaction; Scleroderma, Systemic; Sirolimus; Skin; Statistics, Nonparametric; TOR Serine-Threonine Kinases

Sirolimus and everolimus belong to the novel class of immunosuppressant agents known as proliferation signal inhibitors (PSIs). They act by preventing antigen-driven T cell proliferation. While PSIs are widely used in transplantation, there are few reports of PSI usage in the treatment of autoimmune rheumatic diseases. The author has presented a series in the APLAR 2006 conference. This report summarizes the clinical experience with PSIs in the treatment of resistant or relapsed rheumatic diseases where conventional immunosuppressive agents have failed. This is a retrospective review of patients with various autoimmune rheumatic diseases who had sirolimus and everolimus treatment from the rheumatological clinics of Changi Hospital or the Arthritis and Rheumatism Specialist Medical Centre. The period of review was from April 2006 to April 2008. A total of 46 patients were reviewed, 39 females and 7 males. The racial distribution was 33 Chinese, 7 Malays, and 6 Indians. Their disease conditions were as follows: 26 (57%) rheumatoid arthritis, 7 psoriatic arthritis, 4 systemic lupus erythematosus, 3 scleroderma, 2 anti-Jo-1 syndrome, 2 spondyloarthropathy, 1 MCTD, and 1 vasculitis. All patients had failed at least three DMARDs or immunosuppressants. Twenty-eight patients received sirolimus and 28 patients received everolimus. Overall positive response rate was 48.2%. Twenty-seven percent had adverse events. 20% had no response. 7% relapsed after initial response. PSIs, namely sirolimus and everolimus, are a novel class of immunosuppressants that can be added to the armamentarium of rheumatologists for the treatment of patients with refractory autoimmune rheumatic diseases.

Topics: Adult; Aged; Arthritis, Psoriatic; Arthritis, Rheumatoid; Autoimmune Diseases; Drug Resistance; Everolimus; Female; Humans; Immunosuppressive Agents; Lupus Erythematosus, Systemic; Male; Middle Aged; Molecular Structure; Retrospective Studies; Rheumatic Diseases; Scleroderma, Systemic; Sirolimus; Spondylarthropathies; Treatment Outcome; Vasculitis

Scleroderma is a common autoimmune disorder with no effective therapy. Current concepts of scleroderma include the hypothesis that scleroderma results from excess conversion of endothelial cells to fibroblast like cells, called endothelial mesenchymal transformation. This process is thought to be mediated by cytokines including transforming growth factor beta (TGFb), which causes increased collagen synthesis, resulting in fibrosis, the hallmark of the disease. In vitro studies have hypothesized that rapamycin may be of benefit in scleroderma due to antagonism of collagen synthesis. Given that rapamycin has antiangiogenic activities, inhibits wound healing, and prevents the synthesis of collagen in vivo, we tried rapamycin in a patient with scleroderma. We observed rapid improvement in skin stiffness and mobility. Our results provide the rationale for larger clinical trials of rapamycin in scleroderma and other fibrotic disorders.

Topics: Adult; Angiogenesis Inhibitors; Collagen; Female; Fibrosis; Humans; Immunosuppressive Agents; Mesoderm; Pregnancy; Pregnancy Complications; Scleroderma, Systemic; Sirolimus; Transforming Growth Factor beta; Treatment Outcome