sirolimus and Lupus-Nephritis

Pro-inflammatory immune system development, metabolomic defects, and deregulation of autophagy play interconnected roles in driving the pathogenesis of systemic lupus erythematosus (SLE). Lupus nephritis (LN) is a leading cause of morbidity and mortality in SLE. While the causes of SLE have not been clearly delineated, skewing of T and B cell differentiation, activation of antigen-presenting cells, production of antinuclear autoantibodies and pro-inflammatory cytokines are known to contribute to disease development. Underlying this process are defects in autophagy and mitophagy that cause the accumulation of oxidative stress-generating mitochondria which promote necrotic cell death. Autophagy is generally inhibited by the activation of the mammalian target of rapamycin (mTOR), a large protein kinase that underlies abnormal immune cell lineage specification in SLE. Importantly, several autophagy-regulating genes, including ATG5 and ATG7, as well as mitophagy-regulating HRES-1/Rab4A have been linked to lupus susceptibility and molecular pathogenesis. Moreover, genetically-driven mTOR activation has been associated with fulminant lupus nephritis. mTOR activation and diminished autophagy promote the expansion of pro-inflammatory Th17, Tfh and CD3

Topics: Autophagy; Endothelial Cells; Humans; Lupus Erythematosus, Systemic; Lupus Nephritis; Sirolimus; TOR Serine-Threonine Kinases

Emerging evidence suggested a potential therapeutic role of targeting mTOR in the treatment of SLE. But most studies were observational studies with limited sample size or case reports.. To evaluate the efficacy and safety of sirolimus in treatment of SLE by systematic review and meta-analysis.. Systematic searches of Medline/PubMed, EMBASE, the Cochrane library and Scopus were performed. Original case reports, case series, observational studies and clinical trials reporting the efficacy or safety data on SLE patients treated with sirolimus were included. A random-effects meta-analysis was performed to calculate the pooled efficacy, when possible.. A total of 9 studies comprising 145 patients were identified. The exposure of sirolimus was 245.8 patient-years, with 1-3 mg/day adopted in majority studies. In 111 clinical active patients, the pooled decrease of SLEDAI, BILAG and prednisone dosage was 4.85 (95% CI 3.44-6.25), 1.98 (95% CI 0.23-3.74) and 13.17 mg/day (95% CI 0.71-25.63) respectively. 23 patients initiating sirolimus for active SLE yielded remission in 17 (73.9%) patients. In 22 quiescent lupus nephritis patients, 21 (95.5%) patients sustained remission. Hematological, mucocutaneous abnormalities and dyslipidemia were the most common adverse events. Early cessation due to side effects was reported in 9.28% (13/140) patients, most of the side effects were mild and recovered quickly after cessation.. Summary of the available datasets indicated sirolimus was promising and well-tolerated in the treatment of SLE. Further randomized controlled trials evaluating the potential benefits and risk of sirolimus in SLE are warranted.

Topics: Humans; Lupus Erythematosus, Systemic; Lupus Nephritis; Sirolimus

Lupus nephritis is a common and severe manifestation of systemic lupus erythematosus, and an important cause of both acute kidney injury and end-stage renal disease. Despite its aggressive course, lupus nephritis is amenable to treatment in the majority of patients. The paradigm of immunosuppressive treatment for lupus nephritis has evolved over the past few decades from corticosteroids alone to corticosteroids combined with cyclophosphamide. Sequential treatment regimens using various agents have been formulated for induction and long-term maintenance therapy, and mycophenolate mofetil has emerged as a standard of care option for both induction and maintenance immunosuppressive treatment. The current era has witnessed the emergence of multiple novel therapeutic options, such as calcineurin inhibitors and biologic agents that target key pathogenetic mechanisms of lupus nephritis. Clinical outcomes have improved in parallel with these therapeutic advances. This Review discusses the evidence in support of current standard of care immunosuppressive treatments and emerging therapies, and describes their roles and relative merits in the management of patients with lupus nephritis.

Topics: Antimalarials; Azathioprine; Biological Products; Cyclophosphamide; Cyclosporine; Humans; Immunosuppressive Agents; Isoxazoles; Leflunomide; Lupus Nephritis; Mycophenolic Acid; Ribonucleosides; Severity of Illness Index; Sirolimus; Tacrolimus

This study aimed to explore the therapeutic effect and mechanism of rapamycin (RAPA) on systemic lupus erythematosus (SLE) in BALB/C mice induced by pristane. The mice were randomly divided into 5 groups (n = 6): control, model, saline, RAPA (1 mg/kg) and RAPA (2 mg/kg). All groups were injected with pristane except control. HE staining revealed 1 mg/kg and 2 mg/kg RAPA treatments obviously alleviated pathological changes in the kidney of SLE mice such as glomeruli enlargement, hyperplasia of mesangial cells, epithelial and endothelial cells, infiltration of inflammatory cells, and edema-like degeneration of renal tubules. Compared with control group, body weights and anti-ribosomal P-protein antibody (ARPA) level of the mice in model group and saline group decreased (P < 0.05), while immune complex deposition and levels of anti-dsDNA antibody, anti-smRNP antibody and urine protein in model group and saline group increased (P < 0.05). However, compared with model group and saline group, body weights of the mice in RAPA (1 mg/kg) group and RAPA (2 mg/kg) group increased (P < 0.05), while immune complex deposition and levels of anti-dsDNA antibody, anti-smRNP antibody, ARPA, and urine protein in RAPA (1 mg/kg) group and RAPA (2 mg/kg) group decreased (P < 0.05). Compared with control group, the proportion of dentritic cells (DC) in the kidney and peripheral blood decreased while the proportion of Th1, Th2 and Th17 cells in the spleen, kidney and peripheral blood increased in model group and saline group (P < 0.05). Compared with model group and saline group, 1 mg/kg and 2 mg/kg RAPA treatments boosted the proportion of DC in the kidney and peripheral blood, reduced the proportion of Th1 and Th17 cells in the spleen, kidney and peripheral blood, and lessened the proportion of Th2 cells in the kidney and peripheral blood (P < 0.05). In conclusion, RAPA alleviated renal damage in SLE mice through improving immune response and function.

Topics: Animals; Antibodies, Antinuclear; Antigen-Antibody Complex; Dendritic Cells; Disease Models, Animal; Female; Immunosuppressive Agents; Kidney; Lupus Erythematosus, Systemic; Lupus Nephritis; Mice, Inbred BALB C; Sirolimus; T-Lymphocytes, Helper-Inducer; Terpenes

The safety, tolerance, and selected renal and non-renal outcome measures were evaluated in 73 SLE patients who received sirolimus therapy for more than 3 months in our institution over the past 21 years. In 12 patients who had lupus nephritis, proteinuria (p = 0.0287), hematuria (p = 0.0232), anti-DNA antibody levels (p = 0.0028) and steroid use were reduced (p = 0.0200). In the non-renal cohort of 61 patients, anti-DNA antibody levels (p = 0.0332) and steroid use were reduced (p = 0.0163). Both in the renal and non-renal cohorts, C3 (renal p = 0.0070; non-renal p = 0.0021) and C4 complement levels were increased (renal p = 0.0063; non-renal p = 0.0042) Adverse effects of mouth sores (2/73), headaches (1/73), and gastrointestinal discomfort were noted in a minority of patients (6/73). Sirolimus was only discontinued in two of 73 patients due to headache and recurrent infections, respectively. This study suggests that sirolimus is well tolerated and exerts long-term therapeutic efficacy in controlling renal and non-renal manifestations of SLE.

Topics: Adult; Aged; Antibodies, Antinuclear; Cohort Studies; Female; Follow-Up Studies; Humans; Immunosuppressive Agents; Lupus Erythematosus, Systemic; Lupus Nephritis; Male; Middle Aged; Outcome Assessment, Health Care; Sirolimus; Treatment Outcome

Systemic lupus erythematosus (SLE) is a devastating autoimmune disease in which hyperactive T cells play a critical role. Understanding molecular mechanisms underlying the T cell hyperactivity will lead to identification of specific therapeutic targets. Serine/arginine-rich splicing factor 1 (SRSF1) is an essential RNA-binding protein that controls posttranscriptional gene expression. We have demonstrated that SRSF1 levels are aberrantly decreased in T cells from patients with SLE and that they correlate with severe disease, yet the role of SRSF1 in T cell physiology and autoimmune disease is largely unknown. Here we show that T cell-restricted Srsf1-deficient mice develop systemic autoimmunity and lupus-nephritis. Mice exhibit increased frequencies of activated/effector T cells producing proinflammatory cytokines, and an elevated T cell activation gene signature. Mechanistically, we noted increased activity of the mechanistic target of rapamycin (mTOR) pathway and reduced expression of its repressor PTEN. The mTOR complex 1 (mTORC1) inhibitor rapamycin suppressed proinflammatory cytokine production by T cells and alleviated autoimmunity in Srsf1-deficient mice. Of direct clinical relevance, PTEN levels correlated with SRSF1 in T cells from patients with SLE, and SRSF1 overexpression rescued PTEN and suppressed mTORC1 activation and proinflammatory cytokine production. Our studies reveal the role of a previously unrecognized molecule, SRSF1, in restraining T cell activation, averting the development of autoimmune disease, and acting as a potential therapeutic target for lupus.

Topics: Animals; Autoimmunity; Cytokines; Humans; Lupus Nephritis; Lymphocyte Activation; Mechanistic Target of Rapamycin Complex 1; Mice; Mice, Inbred C57BL; PTEN Phosphohydrolase; Serine-Arginine Splicing Factors; Signal Transduction; Sirolimus; T-Lymphocytes; TOR Serine-Threonine Kinases

Recent studies suggest that defects in macroautophagy/autophagy contribute to the pathogenesis of systemic lupus erythamatosus (SLE), especially in adaptive immunity. The occurrence and progression of lupus nephritis (LN) is the end result of complex interactions between regulation of immune responses and pathological process by renal resident cells, but there is still a lot of missing information for establishing the role of autophagy in the pathogenesis of LN, and as a therapy target. In our recent study, we observed that autophagy is activated in LN, especially in podocytes. Based on in vitro assays, many of the most important mediators of the disease - patients' sera, patients' IgG and IFNA/IFN-α - can induce autophagy in both murine and human podocytes, by reactive oxygen species production or MTORC1 inhibition; autophagy activation negatively associates with podocyte injury. With regard to intervention, autophagy activators can protect against podocyte injury, whereas autophagy inhibitors aggravate injury. Taken together, our findings suggest that podocyte autophagy is involved in lupus renal protection and may be a therapeutic target. These data shed new light on the role of rapamycin and autophagy inducers in the treatment of SLE. Abbreviations: ALB: albumin; ARHGDIB: Rho GDP dissociation inhibitor beta; APOL1: apolipoprotein L1; ATG5: autophagy related 5; ATG7: autophagy related 7; ATG16L2: autophagy related 16 like 2; BECN1: beclin 1; CDKN1B: cyclin dependent kinase inhibitor 1B; CLEC16A, C-type lectin domain containing 16A; CYBB: cytochrome b-245 beta chain; DC: dendritic cell; DRAM1: DNA damage regulated autophagy modulator 1; eQTL: expression quantitative trait loci; GWAS: genome-wide association study; IFNA: interferon alpha; IRGM: immunity related GTPase M; LRRK2: leucine rich repeat kinase 2; MAP1LC3B: microtubule associated protein 1 light chain 3 beta; MTMR3: myotubularin related protein 3; LAP" LC3-associated phagocytosis; LN: lupus nephritis; NOD: non-obese diabetic; NPHS2: NPHS2, podocin; PBMC: peripheral blood mononuclear cell; RUBCN: rubicon autophagy regulator; SLE: systemic lupus erythematosus.

Topics: Animals; Autophagy; Autophagy-Related Protein 5; Humans; Inflammation; Kidney; Lupus Erythematosus, Systemic; Lupus Nephritis; Mice; Microtubule-Associated Proteins; Molecular Targeted Therapy; Phagocytosis; Podocytes; Sirolimus

Lupus nephritis (LN) is one of the principal causes of mortality and disability in patients with systemic lupus erythematosus. Sirolimus has been used to treat patients with LN; however, the effects and mechanism of sirolimus in these patients remains unclear. The present study aimed to elucidate the therapeutic effects and mechanisms of sirolimus in LN mice using low, medium and high doses of sirolimus (0.1, 0.3 and 1 mg/kg, respectively). The survival probability and kidney index were calculated, and renal fibrosis was determined using Masson's Trichrome staining. The expression levels of E‑cadherin, α‑smooth muscle actin (α‑SMA) and vimentin were assessed via immunofluorescence analysis. Transcriptome analysis of control and sirolimus‑treated LN mice was performed using RNA‑sequencing, differentially expressed gene (DEG) identification and annotation, and Gene Ontology (GO) functional and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment. The results suggested that a medium dose of sirolimus alleviated renal fibrosis and increased the survival rates of mice with LN (P<0.05). Furthermore, transcriptome analysis revealed 334 DEGs associated with LN, 176 of which were upregulated and 158 were downregulated. Following GO functional enrichment, 'biological process', 'molecular function' and 'cellular component' terms were identified. A total of 10 KEGG pathways were enriched, with 'cytokine‑cytokine receptor interaction' and 'interleukin‑17 signaling pathway' being significantly enriched (P<0.05). To the best of our knowledge, the present study is the first to conduct transcriptome analysis of LN mice treated with sirolimus, and demonstrated that a dose of 0.3 mg/kg exerted the greatest therapeutic effects.

Topics: Animals; Computational Biology; Disease Models, Animal; Female; Gene Expression Profiling; Gene Expression Regulation; Gene Ontology; Gene Regulatory Networks; Humans; Lupus Nephritis; Mice; Protein Interaction Mapping; Protein Interaction Maps; Sirolimus; Transcriptome

Lupus nephritis (LN) leads to chronic kidney disease (CKD) through progressive fibrosis. Mycophenolate inhibits inosine monophosphate dehydrogenase and is a standard treatment for LN. The mammalian or mechanistic target of rapamycin (mTOR) pathway is activated in LN. Rapamycin inhibits mTOR and is effective in preventing kidney transplant rejection, with the additional merits of reduced incidence of malignancies and viral infections. The effect of mycophenolate or rapamycin on kidney fibrosis in LN has not been investigated. We investigated the effects of mycophenolate and rapamycin in New Zealand Black and White first generation (NZB/W F1) murine LN and human mesangial cells (HMCs), focusing on mechanisms leading to kidney fibrosis. Treatment of mice with mycophenolate or rapamycin improved nephritis manifestations, decreased anti-double stranded (ds) DNA antibody titer and reduced immunoglobulin G (IgG) deposition in the kidney. Both mycophenolate and rapamycin, especially the latter, decreased glomerular mTOR Ser

Topics: Animals; Chemokine CCL2; Drug Therapy, Combination; Female; Fibrosis; Humans; Kidney; Lupus Nephritis; Mice; Mycophenolic Acid; Phosphorylation; Rabbits; Sirolimus; TOR Serine-Threonine Kinases; Transforming Growth Factor beta1

Lupus nephritis (LN) is one of the most common and severe complications in Systemic lupus erythematosus patients, and the mechanism underlining the pathogenesis of LN is still unknown. Autophagy plays vital roles in maintaining cell homeostasis and is involved in the pathogenesis of many diseases. In this study, we investigated the role of autophagy in the progression of LN.. Autophagic activities in podocytes of both LN patients (Class IV and V) and mice were evaluated. Podocytes were observed by electron microscopy, and autophagic activity was evaluated by immunofluorescence staining and western blot analysis. Apoptotic activity was evaluated by immunohistochemistry, TUNEL assays and flow cytometric analysis.. Significantly greater podocyte injury and discrepant autophagic levels were observed in LN patients. Differentiated mouse podocytes in the LN group showed reduced nephrin expression and increased apoptosis, as well as significantly higher levels of apoptosis-related proteins (cleaved caspase-3 and Bax). In the mice LN group, the increased number of autophagosomes was accompanied by increased LC3-II/LC3-I ratios and decreased p62, suggesting increased autophagic and apoptotic activity in podocytes. Blockade of autophagic activity by 3-MA or siRNA-mediated silencing of Atg5 resulted in decreases in LC3-II/LC3-I ratios, podocyte apoptosis and damage in the mice LN group. Futhermore, Rapamycin treatment increased LC3-II/LC3-I ratios, and enhanced LN-induced apoptosis in podocyte from modal animal.. This study demonstrates that autophagic activity of podocytes is a crucial factor in renal injury by directly affecting the function of podocyte; thus, inhibiting this activity during the early stages of LN is implicated as a potential therapeutic strategy for delaying the progression of LN. Also, clinical application in LN needs to consider patients' pathological type and drugs' comprehensive effectiveness.

Topics: Adenine; Adolescent; Adult; Animals; Apoptosis; Apoptosis Regulatory Proteins; Autophagy; Autophagy-Related Proteins; Case-Control Studies; Cells, Cultured; Disease Models, Animal; Disease Progression; Female; Humans; Lupus Nephritis; Male; Membrane Proteins; Mice, Inbred C57BL; Mice, Inbred MRL lpr; Podocytes; Sirolimus; Young Adult

To expand the limited longterm data on sirolimus treatment in patients with lupus nephritis (LN). Our pilot short-term data suggested efficacy of sirolimus treatment in these patients.. We retrospectively reviewed 16 class III/IV/V patients with LN who have received prednisolone (PSL) and sirolimus either as initial or maintenance treatment.. Sixteen patients received sirolimus treatment (9 because of intolerance to standard immunosuppressants and 7 because of a history of malignancy) for 45.3 ± 36.5 months. In 5 patients, sirolimus and PSL were given as induction for active nephritis, and they showed improvements in proteinuria (2.8 ± 1.9 g/day at baseline, 0.1 ± 0.1 g/day after 36 mos, p = 0.011), anti-dsDNA (107.7 ± 91.9 IU/ml and 37.0 ± 55.4 IU/ml, respectively, p = 0.178), and C3 (54.8 ± 26.1 mg/dl and 86.3 ± 18.6 mg/dl, respectively, p = 0.081). Eleven patients received sirolimus and low-dose PSL as longterm maintenance, and they showed continued improvement in C3 (90.4 ± 18.1 mg/dl and 117.7 ± 25.1 mg/dl at commencement and after 36 mos, respectively, p = 0.025), stable renal function (estimated glomerular filtration rate 58.6 ± 25.8 ml/min and 63.0 ± 29.6 ml/min, respectively, p = 0.239), and proteinuria (0.8 ± 0.7 g/day and 0.7 ± 0.7 g/day respectively, p = 0.252). Renal flare occurred in 1 patient, and another patient who had stage 4 chronic kidney disease when sirolimus was started developed endstage renal failure after 27 months. Sirolimus was discontinued in 5 patients, in 4 cases related to drug side effects. Deterioration of dyslipidemia occurred in 4 patients, but was adequately controlled with statin therapy.. The preliminary evidence suggests that sirolimus may serve as an alternative treatment for patients with LN who do not tolerate standard treatment or who had a history of malignancy, and it has an acceptable longterm safety profile.

Topics: Adult; Drug Therapy, Combination; Female; Humans; Immunosuppressive Agents; Lupus Nephritis; Male; Middle Aged; Prednisolone; Retrospective Studies; Sirolimus; Treatment Outcome

We have shown that bone marrow (BM)-derived mesenchymal stem cells (BM-MSCs) from SLE patients exhibit senescent behavior and are involved in the pathogenesis of SLE. The aim of this study was to investigate the effects of rapamycin (RAPA) on the senescences and immunoregulatory ability of MSCs of MRL/lpr mice and SLE patients and the underlying mechanisms. Cell morphology, senescence associated β-galactosidase (SA-β-gal) staining, F-actin staining were used to detect the senescence of cells. BM-MSCs and purified CD4+ T cells were co-cultured indirectly. Flow cytometry was used to inspect the proportion of regulatory T (Treg) /T helper type 17 (Th17). We used small interfering RNA (siRNA) to interfere the expression of mTOR, and detect the effects by RT-PCR, WB and immunofluorescence. Finally, 1x106 of SLE BM-MSCs treated with RAPA were transplanted to cure the 8 MRL/lpr mice aged 16 weeks for 12 weeks. We demonstrated that RAPA alleviated the clinical symptoms of lupus nephritis and prolonged survival in MRL/lpr mice. RAPA reversed the senescent phenotype and improved immunoregulation of MSCs from MRL/lpr mice and SLE patients through inhibition of the mTOR signaling pathway. Marked therapeutic effects were observed in MRL/lpr mice following transplantation of BM-MSCs from SLE patients pretreated with RAPA.

Topics: Animals; beta-Galactosidase; Cell Shape; Cells, Cultured; Cellular Senescence; Disease Models, Animal; Female; Humans; Immunosuppressive Agents; Lupus Erythematosus, Systemic; Lupus Nephritis; Mesenchymal Stem Cells; Mice; Mice, Inbred MRL lpr; Signal Transduction; Sirolimus; TOR Serine-Threonine Kinases

Th17 cells infiltrate the kidneys of patients with lupus nephritis (LN) and are critical for the pathogenesis of this disease. In this study, we show that enhanced activity of Stat3 in CD4(+)CD45RA(-)Foxp3(-) and Foxp3(low) effector T cells from children with LN correlates with increased frequencies of IL-17-producing cells within these T cell populations. The levels of retinoic acid-related orphan receptor c and IL-17 mRNA are significantly higher in PBMCs from children with LN than in those from controls. Mammalian target of rapamycin inhibition by rapamycin reduces both Stat3 activation in effector T cells and the frequency of IL-17-producing T cells in lupus patients. Complement factor C5a slightly increases the expression of IL-17 and induces activation of Akt in anti-CD3-activated lupus effector T cells. Th17 cells from children with LN exhibit high Akt activity and enhanced migratory capacity. Inhibition of the Akt signaling pathway significantly decreases Th17 cell migration. These findings indicate that the Akt signaling pathway plays a significant role in the migratory activity of Th17 cells from children with LN and suggest that therapeutic modulation of the Akt activity may inhibit Th17 cell trafficking to sites of inflammation and thus suppress chronic inflammatory processes in children with LN.

Topics: Adolescent; Cell Movement; Child; Complement C5a; Female; Forkhead Transcription Factors; Gene Expression Regulation; Humans; Immunosuppressive Agents; Interleukin-17; Kidney; Leukocyte Common Antigens; Lupus Nephritis; Male; Primary Cell Culture; Proto-Oncogene Proteins c-akt; Receptors, Retinoic Acid; Signal Transduction; Sirolimus; STAT3 Transcription Factor; T-Lymphocytes, Regulatory; Th17 Cells; TOR Serine-Threonine Kinases

Proliferation signal inhibitors (PSI) have demonstrated efficacy in prevention and treatment in an animal model of lupus nephritis (LN) but there are no data regarding the use of PSI in human LN. We report here our experience of using PSI treatment in seven patients with severe proliferative lupus nephritis.. This is a retrospective study on patients with proliferative lupus nephritis who had received PSI treatment.. Seven patients were included. Two patients had concomitant membranous lupus nephropathy. The indications for PSI included mycophenolate mofetil intolerance (n = 4), history of malignancy (n = 2) and leucopoenia (n = 1). Five patients were given PSI when disease was active. Two had treatment discontinued because of acute cholecystitis and leucopoenia, respectively. In the other three patients combined steroid and PSI treatment as induction therapy led to improvements in serology, renal function and proteinuria. In two patients treated with PSI and low-dose steroid as maintenance immunosuppression, both maintained stable lupus serology, renal function and proteinuria over 18 months. Side-effects included dyslipidemia and oral ulcers.. Proliferation signal inhibitors warrants further investigation as an alternative immunosuppressive treatment in lupus nephritis.

Topics: Adrenal Cortex Hormones; Adult; Cell Proliferation; Drug Therapy, Combination; Everolimus; Female; Humans; Immunosuppressive Agents; Kidney; Lupus Nephritis; Middle Aged; Protein Kinase Inhibitors; Retrospective Studies; Severity of Illness Index; Signal Transduction; Sirolimus; Tacrolimus; Time Factors; TOR Serine-Threonine Kinases; Treatment Outcome

The mammalian target of rapamycin (mTOR) inhibitor, rapamycin, has been shown to inhibit the progression of murine lupus nephritis by virtue of its potent immunosuppressive properties. The phosphoinositol-3-kinase (PI3K)/Akt pathway is a major upstream activator of mTOR and has been implicated in the propagation of cancer and autoimmunity. However, the activation status of the PI3K/Akt/mTOR pathway in lupus nephritis has not been studied so far.. In NZBW/F1 female mice, we examined the glomerular expression of Akt and mTOR by immunofluorescence and western blot. We also searched for specific phosphorylations of these kinases known to ensue during activation of the PI3K/Akt/mTOR pathway. In parallel, we examined the therapeutic role of rapamycin either before or after the development of overt lupus nephritis.. We found that in untreated mice, as opposed to healthy controls, Akt and mTOR were over-expressed and phosphorylated at key activating residues. Rapamycin prolonged survival, maintained normal renal function, normalized proteinuria, restored nephrin and podocin levels, reduced anti-dsDNA titres, ameliorated histological lesions, and reduced Akt and mTOR glomerular expression activation.. These results suggest that: (i) the PI3K/Akt/mTOR pathway is upregulated in murine lupus nephritis, thus justifying treatment with rapamycin; (ii) rapamycin not only blocks mTOR but also negatively regulates the PI3K/Akt/mTOR pathway; and (iii) rapamycin is an effective treatment of murine lupus nephritis. Examination of the PI3K/Akt/mTOR pathway may offer new insights into the pathogenesis of lupus nephritis in humans and may lead to more individualized and less toxic treatment.

Topics: Animals; Down-Regulation; Female; Immunosuppressive Agents; Lupus Nephritis; Mice; Oncogene Protein v-akt; Phosphatidylinositol 3-Kinases; Signal Transduction; Sirolimus; TOR Serine-Threonine Kinases; Up-Regulation

Rapamycin is a potent immunosuppressive drug currently used mainly for rejection prophylaxis in renal transplantation. The aim of this study was to determine the effect of rapamycin treatment on the development of nephritis in lupus-prone New Zealand Black/White F1 (NZB/W F1) mice. Twelve-week-old female NZB/W F1 mice were treated with rapamycin (3 mg/kg body weight) or saline once daily by oral gavage for 20 weeks. The severity of nephritis was assessed by clinical and biochemical parameters, renal histology, immunohistochemistry and gene expression studies. Rapamycin treatment markedly reduced proteinuria, improved renal function, decreased serum anti-double stranded DNA antibody levels and diminished splenomegaly. Kidney sections from saline-treated mice showed marked mesangial proliferation, tubular dilation with protein cast deposition and interstitial inflammatory cell infiltration. Rapamycin-treated mice had near normal renal histology, with marked reduction in glomerular immune deposition and the infiltration by T cells, B cells and macrophages. Rapamycin treatment was associated with down-regulation of intra-renal expression of monocyte chemoattractant protein-1 (MCP-1) mRNA and protein. We conclude that rapamycin is highly effective in preventing the development of nephritis in NZB/W F1 mice. The beneficial effects of rapamycin are mediated through inhibition of lymphoproliferation and reduced MCP-1 expression.

Topics: Administration, Oral; Animals; Antibodies, Antinuclear; Cell Proliferation; Chemokine CCL2; Cytokines; Disease Models, Animal; Dose-Response Relationship, Drug; Female; Gene Expression; Immunohistochemistry; Immunosuppressive Agents; Kidney Glomerulus; Lupus Nephritis; Mice; Mice, Inbred NZB; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger; Sirolimus; T-Lymphocytes

Rapamycin is a potent immunosuppressive drug with proven efficacy in rejection prophylaxis in solid organ transplantation. By virtue of its immunosuppressive properties, rapamycin might also be useful in the treatment of autoimmune diseases. The aim of this study was to determine the effect of rapamycin on the severity of established nephritis in lupus-prone New Zealand Black/White F(1) (NZB/W F(1)) mice.. Six-month-old female NZB/W F(1) mice with active nephritis (albuminuria >100 mg/dL) were treated with rapamycin (3 mg/kg body weight) or saline once daily by oral gavage for 4 months. The effect of rapamycin on the severity of nephritis was evaluated by clinical manifestations, biochemical parameters, renal histology, immunohistochemistry and semi-quantitative gene expression studies.. Treatment with rapamycin significantly decreased albuminuria, improved survival, diminished splenomegaly, preserved renal function and reduced serum anti-dsDNA antibody levels. Kidney sections from saline-treated mice revealed marked mesangial proliferation, tubular dilation with intra-tubular protein cast deposition and leukocytic infiltration of the interstitium. The rapamycin-treated mice, in contrast, had relatively mild histological changes in their kidneys. Rapamycin treatment also significantly reduced the amount of immune complex deposition in the glomeruli, suppressed the interstitial infiltration by T-cells, B-cells and macrophages as well as down-regulated the intra-renal expression of RANTES.. We conclude that rapamycin is effective in attenuating the severity of established nephritis in NZB/W F(1) mice. The beneficial effects of rapamycin are mediated, at least in part, through inhibition of lymphoproliferation, reduced RANTES expression and decreased inflammatory cell infiltration in the kidneys. Rapamycin could be of therapeutic value in the treatment of human lupus nephritis.

Topics: Albuminuria; Animals; Autoimmunity; Chemokine CCL5; Female; Immunosuppressive Agents; Kidney; Lupus Nephritis; Mice; Mice, Inbred NZB; Nephritis; Sirolimus; Splenomegaly

Renal involvement in systemic lupus erythematosus is a common complication that significantly worsens morbidity and mortality. Although treatment with corticosteroids and cytotoxic drugs may be useful in many cases, morbidity associated with these drugs and the relapsing nature of the disease make it necessary to develop new treatment strategies. Five-month old female NZB/W F1 mice were divided into the following groups: CYP group (n = 10), cyclophosphamide (CYP) 50 mg/kg intraperitoneally every 10 days; RAPA 1 group (n = 10) oral daily sirolimus (SRL), 1 mg/kg; RAPA 12 group (n = 13), oral daily SRL, 12mg/kg; FTY group (n = 10), oral fingolimod (FTY720), 2 mg/kg three times per week. An additional group of 13 non-treated mice were used as a control (control group). Follow-up was performed over four months. Animal survival, body weight, anti-DNA antibodies and proteinuria were determined. Kidneys were processed for conventional histology and immunofluorescence for IgG and complement. Total histological score (HS) was the sum of mesangial expansion, endocapillary proliferation glomerular deposits, extracapillary proliferation, interstitial infiltrates, tubular atrophy and interstitial fibrosis. All treated groups had lower proteinuria at the end of the follow-up with respect to the control group (P < 0.0001). Serum anti-DNA antibodies were appropriately controlled in RAPA 1 and CYP groups, but not in FTY or RAPA 12 groups. SRL and CYP arrested, and perhaps reversed almost all histological lesions. FTY720 ameliorated histological lesions but did not control mesangial expansion or interstitial infiltrates. SRL produces great improvement in murine lupus nephritis, while FTY720 seems a promising alternative if used in appropriate doses.

Topics: Administration, Oral; Animals; Antibodies, Antinuclear; Apoptosis; Autoantigens; Cell Movement; Chromatin; Complement C3; Complement C3 Nephritic Factor; Cyclophosphamide; Disease Models, Animal; Dose-Response Relationship, Drug; Drug Evaluation, Preclinical; Female; Fingolimod Hydrochloride; Glomerular Mesangium; Immunoglobulin G; Immunosuppressive Agents; Injections, Intraperitoneal; Kidney Glomerulus; Lupus Nephritis; Lymphocytes; Mice; Mice, Inbred NZB; Nucleosomes; Propylene Glycols; Proteinuria; Receptors, Lysosphingolipid; Sirolimus; Sphingosine

Sirolimus is a new immunosuppressive drug used to avoid allograft rejection. The immunosuppressive effect of sirolimus is due to inhibition of the mammalian target of rapamycin, necessary for the proliferation and clonal expansion of activated T-cells. Because T-cells play a central role in the pathogenesis of autoimmune disease developed in (NZBxNZW)F1 mice, we evaluated the therapeutic use of sirolimus in such mice. (NZBxNZW)F1 female mice received 1mg/kg/day of sirolimus from 12 to 37 weeks of age. The development of autoimmune disease was evaluated by measuring the serum levels of auto-antibodies (autoAbs) and their immunoglobulin isotypes, prevalence of glomerulonephritis and mortality rates. Sirolimus directly inhibited production of autoAbs, glomerular deposits of immunoglobulins and development of proteinuria; also the survival of these mice was prolonged. Our results demonstrate the beneficial effects of sirolimus in preventing the development of lupus disease in (NZBxNZW)F1 female mice.

Topics: Animals; Autoantibodies; Autoimmune Diseases; Female; Immunoglobulin Isotypes; Immunosuppressive Agents; Lupus Erythematosus, Systemic; Lupus Nephritis; Mice; Mice, Inbred NZB; Proteinuria; Sirolimus; Survival Rate; Treatment Outcome