Project description:Background: Synovial inflammation is associated with pain severity in patients with knee osteoarthritis (OA). The aim here was to determine in a population with knee OA, whether synovial tissue from areas associated with pain exhibited different synovial fibroblast transcriptomes, compared to synovial tissue from sites not associated with pain. A further aim was to compare differences between early and end-stage disease synovial fibroblasts. Methods: Patients with early knee OA (n=29) and end-stage knee OA (n=22) were recruited. Patient reported pain was recorded by questionnaire and using an anatomical knee pain map. Proton density fat suppressed MRI axial and sagittal sequences were analysed and scored for synovitis. Synovial tissue was obtained from the medial and lateral parapatellar and suprapatellar sites. RNA sequencing was performed using Illumina’s NextSeq 500 and analysed with Galaxy web platform, usegalaxy.org, and Qlucore software. Transcriptomes were functionally characterised using Ingenuity Pathway Analysis. Findings: Parapatellar synovitis was significantly associated with increased OA pain perception. Functional pathway analysis revealed that early OA painful sites mediate immune cell recruitment and promote the formation and development of neurites. Conclusion: OA disease progression and the presence of pain in early OA is associated with different synovial pathotypes. Further interrogation of these pathotypes will increase our understanding of the role of synovitis in OA joint pain and provide a rationale for the therapeutic targeting to alleviate pain in patients.
Project description:Synovial fluid (SF)-derived monocyte–macrophage lineage (MON–Mϕ) cells in knee osteoarthritis (KOA) remain poorly understood. This lineage consists of four subpopulations with considerable interindividual variability that correlates with the distribution and activation of other immune cells. The most abundant subpopulation was that of CD11b+CD14−CD16− myeloid dendritic cells (mDCs; type cDC2), which were inactive and exhibited low cytokine production, low T-lymphocyte stimulation, high migratory ability comparing to other MON–Mϕ cells. Other major subpopulations included CD11b+CD14+CD16− monocyte-like cells and CD11b+CD14+CD16+ macrophages. A subpopulation of CD11b−CD14−CD16− mDCs (type cDC1) was less common. To confirm the identity of MON–Mϕ subpopulations characterised through flow cytometry, we performed bulk RNA-seq analysis on sorted CD11b+CD14−CD16−, CD11b+CD14+CD16− and CD11b+CD14+CD16+ MON–Mϕ subpopulations from the SF of four patients with KOA with a predominance of MON–Mϕ lineage cells. The CD11b+CD14+CD16− and CD11b+CD14+CD16+ cells shared a similar transcriptomic profile. However, CD11b+CD14−CD16− cells were remarkably distinct from other CD11b+ populations. The dataset is part of a study published by Mikulkova et al. Cell Reports.
Project description:Osteoarthritis is characterized by degeneration of cartilage and bone in the synovial joints. Recent findings suggest that inflammation may play a role in osteoarthritis, with synovitis being associated with the clinical symptoms of osteoarthritis. Furthermore, we have found that levels of inflammatory complement components are abnormally high in the synovial fluid of individuals with osteoarthritis. To determine whether synovial membranes could be a source of complement and other inflammatory molecules in osteoarthritic joints, we characterized the expression of genes in synovial membranes from patients with early-stage or end-stage osteoarthritis. Samples of synovial membrane were obtained from the suprapatellar pouch of patients with osteoarthritis who were treated at the Hospital for Special Surgery. Specifically, samples were from 10 patients with early-stage knee osteoarthritis who were undergoing arthroscopic procedures for degenerative meniscal tears (with documented cartilage degeneration but no full-thickness cartilage loss, Kellgren Lawrence score </=2), and from 9 patients with end-stage knee osteoarthritis ( diffuse full thickness cartilage erosion) who were undergoing total knee joint replacement. Raw data from microarray analysis of healthy synovial membranes, which were run on the same platform and array as our osteoarthritic samples, were downloaded from the NCBI Gene Expression Omnibus (accession number GSE12021) and used for comparison. The 19 new Samples of this Series were analyzed (RMA) together with 7 previously submitted healthy individual Samples (GSM175810, GSM175812, GSM176290, GSM176291, GSM176292, GSM176268, GSM176269). The complete RMA data are provided as a supplementary file on the Series record. The GSE12021 reanalyzed data are also provided as a supplementary file on the Series record. GSE32317_12genes.txt includes data from figure 1 of the paper.
Project description:Synovial inflammation is associated with pain severity in patients with knee osteoarthritis (OA). The aim here was to determine in a population with knee OA, whether synovial tissue from areas associated with pain exhibited different synovial fibroblast subsets, compared to synovial tissue from sites not associated with pain. A further aim was to compare differences between early and end-stage disease synovial fibroblast subsets. Parapatellar synovitis was significantly associated with the pattern of patient-reported pain in knee OA patients. Synovial tissue from sites of patient-reported pain exhibited a differential transcriptomic phenotype, with distinct synovial fibroblast subsets in early OA and end-stage OA. Functional pathway analysis revealed that synovial tissue and fibroblast subsets from painful sites promoted fibrosis, inflammation and the growth and activity of neurons. The secretome of fibroblasts from early OA painful sites induced neurite outgrowth in dorsal root ganglion neurons. Sites of patient-reported pain in knee OA is associated with a different synovial tissue phenotype and distinct synovial fibroblast subsets. Further interrogation of these fibroblast pathotypes will increase our understanding of the role of synovitis in OA joint pain and provide a rationale for the therapeutic targeting of fibroblast subsets to alleviate pain in patients.
Project description:Using transcriptome sequencing to screen the differntent expression genes in MIA-induced knee osteoarthritis (KOA) model rats compared with normal rats.
Project description:Patients with anterior cruciate ligament (ACL) tears have a significantly increased risk for developing knee osteoarthritis. These injuries often result in a knee effusion in response to the injury. Early changes in these effusions could be informative regarding initial steps in the development of post traumatic osteoarthritis. The purpose of this study was to test the hypothesis that the proteomics of knee synovial fluid changes over time following ACL injury.
Project description:The aim of this study was to compare the gene expression pattern of synovial cells from inflammatory (I) or normal/reactive (N/R) areas of a synovial membrane harvested from the same osteoarthritis (OA) patient. This study is the first to identify different expression pattern between two areas of the synovial membrane in the same patient. These differences concern several key pathways involved in OA pathogenesis (inflammation, cartilage metabolism, Wnt signaling and angiogenesis). This analysis also provides interesting information regarding new potent intermediates as potentiel targets for the future therapeutic. Synovial tissues were obtained from 12 knee OA patients at the time of total knee replacement. The inflammatory status of the synovial membrane was characterized according to macroscopic criteria and sorted as N/R and I. Biopsies were cultured separately for 7 days. Microarray gene expression profiling between N/R and I areas was performed.