Project description:Up to 75% of systematic lupus erythematosus (SLE) patients experience neuropsychiatric (NP) symptoms, called neuropsychiatric SLE (NPSLE), yet the underlying mechanisms remain elusive. Microglia control synaptic pruning during early postnatal brain development. The process in NPSLE remains unclear. Here, we show that microglia-coordinated elimination of synaptic terminals participated in NPSLE in MRL/lpr mice, a lupus-prone murine model. We elucidated that lupus mice developed increased depression- and anxiety-like behaviors and persistent phagocytic microglia reactivation before overt peripheral lupus pathology. Microglial engulfment of synapses explained behavioral disorders. To elucidate the mechanism of synaptic pruning by microglia, we sequenced the gene expression in sorted microglia from both lupus (MRL/lpr) mice and the wild-type (MRL/mpj) controls.
Project description:Up to 75% of systematic lupus erythematosus (SLE) patients experience neuropsychiatric (NP) symptoms, called neuropsychiatric SLE (NPSLE), yet the underlying mechanisms remain elusive. Complement cascades mediate synaptic pruning by microglia during early postnatal brain development. The process in NPSLE remains unclear. Here, we show that complement-coordinated elimination of synaptic terminals participated in NPSLE in MRL/lpr mice, a lupus-prone murine model. We elucidated that lupus mice developed increased anxiety-like behaviors and persistent phagocytic microglia reactivation before overt peripheral lupus pathology. Microglial engulfment of synapses explained behavioral disorders. We further determined that neuronal Nr4a1 signaling was essential for attracting C1q synaptic deposition then apposition of phagocytic microglia, ensuing synaptic loss and neurological disease. Minocycline-deactivated microglia, antibody-blocked C1q, or neuronal Nr4a1 restore protected lupus mice from synapse loss and NP manifestations. Our findings revealed an active role of neurons in coordinating microglia-mediated synaptic loss and highlight neuronal Nr4a1 and C1q as critical components amenable to pharmacological intervention.
Project description:To identify any differentially expressed miRNAs in the CD4+ T cells of lupus. MicroRNAs (miRNAs) have been implicated as fine-tuning regulators controlling diverse biological processes at the level of posttranscriptional repression. Dysregulation of miRNAs has been described in various disease states, including human lupus. By using high-throughput microRNA profiling analysis, we identified that two miRNAs (miR-21 and miR-148a) overexpressed in CD4+ T cells from both lupus patients and lupus-prone MRL/lpr mice,which promote cell hypomethylation by repressing DNA methyltransferase 1 (DNMT1) expression. We isolated the splenic CD4+ T cells and B cells from MRL/lpr mice at 5 and 16 weeks of age.Cells were collected and total RNA was extracted for the TaqMan® Low Density Assay v2.0 Normalization was performed with snoRNA202, reference snRNAs for mouse.Comparative real-time PCR was performed in triplicate, including no-template.controls. Relative expression was calculated with the comparative cycle threshold method.
Project description:We investigated whether mouse serum autoantibody binding patterns on random-sequence peptide microarrays (immunosignaturing) can be used for diagnosing and predicting the onset of lupus and its central nervous system (CNS) manifestations. Submitter states "We have no processed data to submit. We have no gpr files to submit." To identify possible predictive and diagnostic peptides of lupus and CNS-lupus, we carried out two studies and selected peptides in common across both studies. In the first study we tested 3-6 MRL/lpr, MRL/mp and C3H/HeJ mice at four months of age. For study two we tested 9-10 MRL/lpr and MRL/mp at 1.5 and 4 months of age. In both studies the mice sera were diluted 1/500 and analyzed using microarray peptides from platform GPL14921. We ran each sample in triplicate. The MRL/lpr and MRL/mp are the autoimmune strains and the C3H/HeJ is the control strain.
Project description:To identify any differentially expressed miRNAs in the CD4+ T cells of lupus. MicroRNAs (miRNAs) have been implicated as fine-tuning regulators controlling diverse biological processes at the level of posttranscriptional repression. Dysregulation of miRNAs has been described in various disease states, including human lupus. By using high-throughput microRNA profiling analysis, we identified that two miRNAs (miR-21 and miR-148a) overexpressed in CD4+ T cells from both lupus patients and lupus-prone MRL/lpr mice,which promote cell hypomethylation by repressing DNA methyltransferase 1 (DNMT1) expression.
Project description:Mesenchymal stem cell transplantation (MSCT) has been widely used to treat a variety of human diseases. However, the detailed mechanisms underlying its success are not fully understood. Here we show that MSCT rescues recipient bone marrow mesenchymal stem cell (BMMSC) function in Fas-deficient-MRL/lpr systemic lupus erythematosus (SLE) mice via a miR-29b/Dnmt1/Notch epigenetic cascade. Using the microRNA microarray, we found that MSCT could rescue the high level of miR-29b in the recipient BMMSCs of MRL/lpr mice. In the present study, mesenchymal stem cell transplantation (MSCT) was used to treat MRL/lpr mice. One week after the treatment, normal control MSCs from C3H/HeJ mice (C3H), recipient MSCs from untreated MRL/lpr mice (LPR) and recipient MSCs from MSCT-treated MRL/lpr mice (MSC) were used for total RNA extraction and microRNA microarray for analysis of microRNA expressions.
Project description:MicroRNAs (miRNAs) have been implicated as fine-tuning regulators controlling diverse biological processes at the level of posttranscriptional repression. Dysregulation of miRNAs has been described in various disease states, including inflammatory autoimmune diseases. By using high-throughput microRNA profiling analysis, we identified a series of miRNAs dysregulated in local inflammatory lesions of human patients with autoimmune diseases, as well as their relevant mouse models such as MRL/lpr. We isolated the kidneys tissues pooled from six female MRL/lpr mice or from three control mice. Total RNA was extracted for the TaqManM-BM-. Low Density Assay v3.0
Project description:Mesenchymal stem cell transplantation (MSCT) has been widely used to treat a variety of human diseases. However, the detailed mechanisms underlying its success are not fully understood. Here we show that MSCT rescues recipient bone marrow mesenchymal stem cell (BMMSC) function in Fas-deficient-MRL/lpr systemic lupus erythematosus (SLE) mice via a miR-29b/Dnmt1/Notch epigenetic cascade. Using the microRNA microarray, we found that MSCT could rescue the high level of miR-29b in the recipient BMMSCs of MRL/lpr mice.