Multidimensional Single Cell Based STAT Phosphorylation Profiling Identifies a Novel Biosignature for Evaluation of Systemic Lupus Erythematosus Activity

INTRODUCTION: Dysregulated cytokine action on immune cells plays an important role in the initiation and progress of systemic lupus erythematosus (SLE), a complex autoimmune disease. Comprehensively quantifying basal STATs phosphorylation and their signaling response to cytokines should help us to better understand the etiology of SLE. METHODS: Phospho-specific flow cytometry was used to measure the basal STAT signaling activation in three immune cell types of peripheral-blood mononuclear cells from 20 lupus patients, 9 rheumatoid arthritis (RA) patients and 13 healthy donors (HDs). A panel of 27 cytokines, including inflammatory cytokines, was measured with Bio-Plex™ Human Cytokine Assays. Serum Prolactin levels were measured with an immunoradiometric assay. STAT signaling responses to inflammatory cytokines (interferon α [IFNα], IFNγ, interleukin 2 [IL2], IL6, and IL10) were also monitored. RESULTS: We observed the basal activation of STAT3 in SLE T cells and monocytes, and the basal activation of STAT5 in SLE T cells and B cells. The SLE samples clustered into two main groups, which were associated with the SLE Disease Activity Index 2000, their erythrocyte sedimentation rate, and their hydroxychloroquine use. The phosphorylation of STAT5 in B cells was associated with cytokines IL2, granulocyte colony-stimulating factor (G-CSF), and IFNγ, whereas serum prolactin affected STAT5 activation in T cells. The responses of STAT1, STAT3, and STAT5 to IFNα were greatly reduced in SLE T cells, B cells, and monocytes, except for the STAT1 response to IFNα in monocytes. The response of STAT3 to IL6 was reduced in SLE T cells. CONCLUSIONS: The basal activation of STATs signaling and reduced response to cytokines may be helpful us to identify the activity and severity of SLE

Nicotinic acetylcholine receptors modulate osteoclastogenesis

Background: Our aim was to investigate the role of nicotinic acetylcholine receptors (nAChRs) in in-vitro osteoclastogenesis and in in-vivo bone homeostasis. Methods: The presence of nAChR subunits as well as the in-vitro effects of nAChR agonists were investigated by ex vivo osteoclastogenesis assays, real-time polymerase chain reaction, Western blot and flow cytometry in murine bone marrow-derived macrophages differentiated in the presence of recombinant receptor activator of nuclear factor kappa B ligand (RANKL) and macrophage colony-stimulating factor (M-CSF). The bone phenotype of mice lacking various nAChR subunits was investigated by peripheral quantitative computed tomography and histomorphometric analysis. Oscillations in the intracellular calcium concentration were detected by measuring the Fura-2 fluorescence intensity. Results: We could demonstrate the presence of several nAChR subunits in bone marrow-derived macrophages stimulated with RANKL and M-CSF, and showed that they are capable of producing acetylcholine. nAChR ligands reduced the number of osteoclasts as well as the number of tartrate-resistant acidic phosphatase-positive mononuclear cells in a dose-dependent manner. In vitro RANKL-mediated osteoclastogenesis was reduced in mice lacking α7 homomeric nAChR or β2-containing heteromeric nAChRs, while bone histomorphometry revealed increased bone volume as well as impaired osteoclastogenesis in male mice lacking the α7 nAChR. nAChR ligands inhibited RANKL-induced calcium oscillation, a well-established phenomenon of osteoclastogenesis. This inhibitory effect on Ca2+ oscillation subsequently led to the inhibition of RANKL-induced NFATc1 and c-fos expression after long-term treatment with nicotine. Conclusions: We have shown that the activity of nAChRs conveys a marked effect on osteoclastogenesis in mice. Agonists of these receptors inhibited calcium oscillations in osteoclasts and blocked the RANKL-induced activation of c-fos and NFATc1. RANKL-mediated in-vitro osteoclastogenesis was reduced in α7 knockout mice, which was paralleled by increased tibial bone volume in male mice in vivo. © 2016 Mandl et al

Non-classical monocytes as mediators of tissue destruction in arthritis

Contains fulltext : 196916.pdf (publisher's version ) (Open Access)OBJECTIVES: Bone destruction in rheumatoid arthritis is mediated by osteoclasts (OC), which are derived from precursor cells of the myeloid lineage. The role of the two monocyte subsets, classical monocytes (expressing CD115, Ly6C and CCR2) and non-classical monocytes (which are CD115 positive, but low in Ly6C and CCR2), in serving as precursors for OC in arthritis is still elusive. METHODS: We investigated CCR2(-/-) mice, which lack circulating classical monocytes, crossed into hTNFtg mice for the extent of joint damage. We analysed monocyte subsets in hTNFtg and K/BxN serum transfer arthritis by flow cytometry. We sorted monocyte subsets and analysed their potential to differentiate into OC and their transcriptional response in response to RANKL by RNA sequencing. With these data, we performed a gene ontology enrichment analysis and gene set enrichment analysis. RESULTS: We show that in hTNFtg arthritis local bone erosion and OC generation are even enhanced in the absence of CCR2. We further show the numbers of non-classical monocytes in blood are elevated and are significantly correlated with histological signs of joint destruction. Sorted non-classical monocytes display an increased capacity to differentiate into OCs. This is associated with an increased expression of signal transduction components of RANK, most importantly TRAF6, leading to an increased responsiveness to RANKL. CONCLUSION: Therefore, non-classical monocytes are pivotal cells in arthritis tissue damage and a possible target for therapeutically intervention for the prevention of inflammatory joint damage

Methods of deriving EULAR/ACR recommendations on reporting disease activity in clinical trials of patients with rheumatoid arthritis

OBJECTIVE: To use an evidence-based and consensus-based approach to elaborate recommendations on how to report disease activity in clinical trials of patients with rheumatoid arthritis (RA) endorsed by the European League Against Rheumatism (EULAR) and the American College of Rheumatology (ACR). METHODS: After an initial expert meeting, during which relevant research questions were identified, a systematic literature search was performed using Medline, Embase and the Cochrane Library as sources. To ensure literature retrieved was comprehensive, we emphasised search algorithms that were sensitive rather than specific. The results of the literature search were discussed by the expert panel, modified and expanded, and were used as the basis for the elaboration of the recommendation in the consensus process. Finally, an independent ACR panel approved these items with some minor modifications. RESULTS: The following pieces of evidence were obtained from the literature search: (1) timing and the sustaining of a response is relevant to achieve better outcomes; (2) composite disease activity indices have been used to define low disease activity and remission and these definitions have been validated as has the American Rheumatism Association (ARA) remission criteria. The "patient-reported symptom state" (PASS) is not yet well validated; (3) evidence was obtained to identify those measures, scales and patient-reported instruments, for which there is a documented association with relevant outcomes; (4) baseline disease activity is associated with disease activity levels at the end of follow-up; and (5) there was not sufficient evidence relating the added benefit of MRI or ultrasound over clinical assessments. Most data stemmed from observational studies rather than clinical trials and literature review was supplemented by input from experts. The results served as the basis for the elaboration of the seven recommendations by the experts. CONCLUSIONS: The approach based on scientific evidence from the literature as well as on expert input provided sufficient information to derive recommendations on reporting disease activity in RA clinical trials. The methodology, results and conclusions of this project were endorsed by EULAR and the ACR

The Lipid-Modifying Enzyme SMPDL3B Negatively Regulates Innate Immunity

10.1016/j.celrep.2015.05.006Cell Reports11121919-192

Methods of deriving EULAR/ACR recommendations on reporting disease activity in clinical trials of patients with rheumatoid arthritis.

OBJECTIVE: To use an evidence-based and consensus-based approach to elaborate recommendations on how to report disease activity in clinical trials of patients with rheumatoid arthritis (RA) endorsed by the European League Against Rheumatism (EULAR) and the American College of Rheumatology (ACR). METHODS: After an initial expert meeting, during which relevant research questions were identified, a systematic literature search was performed using Medline, Embase and the Cochrane Library as sources. To ensure literature retrieved was comprehensive, we emphasised search algorithms that were sensitive rather than specific. The results of the literature search were discussed by the expert panel, modified and expanded, and were used as the basis for the elaboration of the recommendation in the consensus process. Finally, an independent ACR panel approved these items with some minor modifications. RESULTS: The following pieces of evidence were obtained from the literature search: (1) timing and the sustaining of a response is relevant to achieve better outcomes; (2) composite disease activity indices have been used to define low disease activity and remission and these definitions have been validated as has the American Rheumatism Association (ARA) remission criteria. The "patient-reported symptom state" (PASS) is not yet well validated; (3) evidence was obtained to identify those measures, scales and patient-reported instruments, for which there is a documented association with relevant outcomes; (4) baseline disease activity is associated with disease activity levels at the end of follow-up; and (5) there was not sufficient evidence relating the added benefit of MRI or ultrasound over clinical assessments. Most data stemmed from observational studies rather than clinical trials and literature review was supplemented by input from experts. The results served as the basis for the elaboration of the seven recommendations by the experts. CONCLUSIONS: The approach based on scientific evidence from the literature as well as on expert input provided sufficient information to derive recommendations on reporting disease activity in RA clinical trials. The methodology, results and conclusions of this project were endorsed by EULAR and the ACR