Project description:Objective: To Identify gene changes in the medial tibial plateau of articular cartilage at 2, 4 and 8 weeks after destabilisation of the medial meniscus (DMM) in mice and compare our data set with previously published sets to ascertain dysregulated pathways and genes in osteoarthritis. Materials and methods: RNA was extracted from the ipsilateral and contralateral medial tibial plateaus, amplified, labelled and hybridized on Illumina WG_v2 microarrays. Results were confirmed by RT-PCR for selected genes. Results: Transcriptional analysis and network reconstruction revealed changes in extracellular matrix (ECM) and cytoskeletal genes induced by DMM. TGFalpha signalling pathway and complement and coagulation cascade genes were regulated at 2 weeks. Fibronectin (FN1) is a hub in a reconstructed network of potential protein-protein interactions at 2 weeks. Regulated genes decrease over time and by eight weeks fibromodulin (FMOD) and tenascin N (TNN) are the only dysregulated genes present in the DMM operated knees. Comparison with human and rodent published gene sets discovered genes overlapping between our array and 6 others. Conclusions: Cartilage contributes a minute percentage to the RNA extracted from the whole joint (>0.2%), yet is sensitive to changes in gene expression post-DMM. The post-DMM transcriptional reprogramming wanes over time and dissipates by 8 weeks. Common pathways between published gene sets include focal adhesion, regulation of actin cytoskeleton and TGFalpha. Common genes include Jagged 1 (Jag1), Tetraspanin 2 (Tspan2), neuroblastoma, suppression of tumourigenicity 1 (Nbl1) and N-myc downstream regulated gene 2 (Ndrg2). The concomitant genes and pathways we identify are novel and warrant further investigation as biomarkers or modulators of osteoarthritis. In total 18 samples. Each sample was a pool of the medial tibial plateau of 8 mice. Two categories (Treated and untreated) with three biological replicates each and three time points (2, 4 and 8 weeks post-surgery).
Project description:Objective: To Identify gene changes in the medial tibial plateau of articular cartilage at 2, 4 and 8 weeks after destabilisation of the medial meniscus (DMM) in mice and compare our data set with previously published sets to ascertain dysregulated pathways and genes in osteoarthritis. Materials and methods: RNA was extracted from the ipsilateral and contralateral medial tibial plateaus, amplified, labelled and hybridized on Illumina WG_v2 microarrays. Results were confirmed by RT-PCR for selected genes. Results: Transcriptional analysis and network reconstruction revealed changes in extracellular matrix (ECM) and cytoskeletal genes induced by DMM. TGFalpha signalling pathway and complement and coagulation cascade genes were regulated at 2 weeks. Fibronectin (FN1) is a hub in a reconstructed network of potential protein-protein interactions at 2 weeks. Regulated genes decrease over time and by eight weeks fibromodulin (FMOD) and tenascin N (TNN) are the only dysregulated genes present in the DMM operated knees. Comparison with human and rodent published gene sets discovered genes overlapping between our array and 6 others. Conclusions: Cartilage contributes a minute percentage to the RNA extracted from the whole joint (>0.2%), yet is sensitive to changes in gene expression post-DMM. The post-DMM transcriptional reprogramming wanes over time and dissipates by 8 weeks. Common pathways between published gene sets include focal adhesion, regulation of actin cytoskeleton and TGFalpha. Common genes include Jagged 1 (Jag1), Tetraspanin 2 (Tspan2), neuroblastoma, suppression of tumourigenicity 1 (Nbl1) and N-myc downstream regulated gene 2 (Ndrg2). The concomitant genes and pathways we identify are novel and warrant further investigation as biomarkers or modulators of osteoarthritis.
Project description:Purpose: RNA sequencing (RNA-Seq) analyses of articular cartilage obtained after DMM surgery in Oscar-/- and WT mice. The purpose of this experiment was to demonstrate how the deficiency of Oscar gene affects downstream signal transduction in articular cartilage. Methods: Articular cartilage mRNA profiles of 10-weeks-old wild-type (WT) and Oscar knockout (Oscar−/−) mice were performed for the destabilization of the medial meniscus (DMM) and each cartilage tissue sample was harvested from two time-points (2- and 4-weeks after surgery). Sequencing libraries were prepared according to the manufacturer’s instructions (TruSeq Stranded mRNA Library Prep Kit; Illumina, San Diego, CA, USA). Paired-end sequencing of 101-mer read length was performed using a HISEQ 2500 sequencing system (Illumina). The sequencing quality of raw FASTQ files was assessed using FastQC (https://www.bioinformatics.babraham.ac.uk/projects/fastqc/). Low-quality reads and adapter sequences in reads were eliminated using BBDuk (http://jgi.doe.gov/data-and-tools/bb-tools/). Results: Usinig RNA-Seq data in articular cartilage tissues from WT and Oscar–/– mice subjected to sham or DMM surgery and each cartilage sample obtained from 2- and 4-week time points after surgery, respectively. And we found that significantly enriched pathways in the 1270 common genes. Conclusions: Our study represents the Oscar gene deficiency analysis of articular cartilage transcriptomes, with biologic replicates, generated by RNA-seq technology. The optimized data analysis workflows reported here should provide a framework for comparative investigations of expression profiles. Our results show that NGS offers a comprehensive and more accurate quantitative and qualitative evaluation of mRNA content within a cell or tissue. We conclude that RNA-seq based transcriptome characterization would expedite genetic network analyses and permit the dissection of complex biologic functions.
Project description:The purpose of this study was to characterize the histologic development of OA in a mouse model where OA is induced by destabilization of the medial meniscus (DMM model) and to identify genes regulated during different stages of the disease, using RNA isolated from the joint M-bM-^@M-^\organM-bM-^@M-^] and analyzed using microarrays.427 genes from the microarrays passed consistency and significance filters. There was an initial up-regulation at 2 and 4 weeks of genes involved in morphogenesis, differentiation, and development, including growth factor and matrix genes, as well as transcription factors including Atf2, Creb3l1, and Erg. Most genes were off or down-regulated at 8 weeks with the most highly down-regulated genes involved in cell division and the cytoskeleton. Gene expression increased at 16 weeks, in particular extracellular matrix genes including Prelp, Col3a1 and fibromodulin.The results support a phasic development of OA with early matrix remodelling and transcriptional activity followed by a more quiescent period that is not maintained. A group of 9 mice was used for collection of RNA at time 0 (before surgery) when the animals were 12 weeks old. For the other time points, 9 DMM and 9 sham controls were sacrificed at 2, 4, 8, and 16 weeks after surgery for RNA isolation. The tissue included tibial plateau and femoral condyle articular cartilage, subchondral bone with any osteophytes, meniscus, and the joint capsule with synovium was used for RNA isolation. The tissue was treated with RNAlaterM-BM-. (Invitrogen) prior to freezing and storage at -800 C. RNA was extracted by homogenization using the Precellys 24 tissue homogenizer (Bertin Technologies purchased from MO BIO) and the amount and quality of the RNA was determined using an Agilent 2100 Bioanalyzer. RNA was pooled prior to microarray analysis such that 3 randomly selected samples from each surgical group and time point were pooled to create each biological replicate. Because 9 mice were used for each experimental group, a total of three biological replicates per group were analyzed using the Affymetrix Mouse Genome 430 2.0 oligonucleotide arrays as described. One replicate pool, which was from week two DMM mice, did not meet the RNA integrity level needed for microarray analysis; thus, this pool was not analyzed further, leaving two pools for the week two DMM mice.
Project description:Objective: We used the destabilization of the medial meniscus (DMM) model to identify temporal changes in DNA methylation patterns associated with structural and transcriptomic changes in cartilage during osteoarthritis (OA) progression. Methods: RNA sequencing (RNAseq) and Reduced Representation Oxidative Bisulfite Sequencing (RRoxBS) analyses were done in total RNA and DNA obtained from micro-dissected cartilage at 4 and 12 weeks after DMM surgery. Murine and human primary chondrocytes were used to evaluate the cytokine- and methylation-dependent changes in the expression of Lrrc15, and its contribution to IL-1beta-induced changes in chondrocytes. Results: We identified time-dependent alterations in epigenomic patterns in cartilage after DMM, with significant changes in 5mC and 5hmC methylation comparing samples retrieved at 4 and 12 weeks after surgery. Integration of RNAseq and RRoxBS datasets identified Lrrc15 as a hypomethylated gene with increased expression at 4 weeks after surgery. We confirmed LRRC15 immunostaining in OA cartilage, and experiments in human and murine primary chondrocytes showed that the expression of Lrrc15 is DNA methylation-dependent and induced by IL1beta and TNFalfa in vitro. Knockdown experiments showed that Lrrc15 contributes to the IL1beta-driven expression of catabolic genes relevant to OA, including Mmp13. Significance: Our integrative analyses showed that the structural progression of OA is accompanied by transcriptomic and dynamic epigenomic changes in articular cartilage. We found that Lrrc15 is differentially methylated and expressed in OA cartilage, and that it may contribute to the cytokine-driven responses of OA chondrocytes. A better understanding of the role of Lrrc15 in cartilage homeostasis and osteoarthritis may help us uncover targets with therapeutic potential.
Project description:We elucidated the molecular cross-talk between knee articular cartilage and paired synovium in n=3 individuals with knee osteoarthritis using the powerful tool of single-cell RNA-sequencing. Multiple cell types were identified based on profiling of 10,640 synoviocytes and 26,192 chondrocytes (11,579 chondrocytes from the diseased medial vs 14,613 chondrocytes from the relatively non-diseased lateral tibial plateau): 12 distinct synovial cell types and 7 distinct articular chondrocyte phenotypes from matched tissues. Intact cartilage was enriched for homeostatic and hypertrophic chondrocytes, while damaged cartilage was enriched for prefibro- and fibro-, regulatory, reparative and prehypertrophic chondrocytes. A total of 61 cytokines and growth factors were predicted to regulate the 7 chondrocyte cell phenotypes. Based on production by >1% of cells, 55% of the cytokines were produced by synovial cells (39% exclusive to synoviocytes and not expressed by chondrocytes) and their presence in osteoarthritic synovial fluid confirmed. The synoviocytes producing IL-1beta (a classic pathogenic cytokine in osteoarthritis), mainly inflammatory macrophages and dendritic cells, were characterized by co-expression of surface proteins corresponding to HLA-DQA1, HLA-DQA2, OLR1 or TLR2. Strategies to deplete these pathogenic intra-articular cell subpopulations could be a therapeutic option for human osteoarthritis.
Project description:Objective Animal models of post-traumatic osteoarthritis (PTOA) recapitulate the pathological changes observed in human PTOA. Here we aimed to compare the cartilage transcriptome responses of a non-surgical, mechanically induced rupture of the anterior cruciate ligament (ACL) model and the surgical destabilisation of the medial meniscus (DMM) model. Methods Skeletally mature male C57Bl6 mice were subjected to either the non-surgical, mechanical ACL rupture or surgical DMM models and transcriptome profiling performed on micro-dissected cartilage at day 7 and 42 post-procedure, respectively; in general, naïve animals served as controls. MicroRNA profiling was also performed on the ACL rupture model. Expression levels of a miRNA of interest, miR-199-5p, were inhibited in primary human articular chondrocytes (HAC) with RNA-seq and 3’UTR assays used to identify and valid potential target genes. Results The number of differentially expressed genes between the two models were comparable and highly correlative (Spearman R =0.8, P<2.2E-16). Gene ontology enrichment analysis identified similarly enriched pathways, containing anabolic terms including ‘extracellular matrix organisation’ enriched for the upregulated genes. Within the ACL rupture miRNA transcriptome, miR-199-5p family members were amongst the most abundantly, and differentially expressed, which was replicated in the DMM cartilage by qRT-PCR. Inhibition of miR-199-5p in HAC led to a comparable transcriptome response to that observed in both human OA damaged vs intact cartilage and murine DMM cartilage datasets. Several genes, including GIT1, NCEH1, SOS2 and ECE1 were all experimentally verified as targets. Conclusion For the first time, we have characterised both the mRNA and miRNA articular cartilage signature in the ACL rupture model and demonstrated highly correlative responses with the DMM PTOA model. These data support the use of the ACL rupture model as a non-invasive alternative to DMM.
Project description:Objective Animal models of post-traumatic osteoarthritis (PTOA) recapitulate the pathological changes observed in human PTOA. Here we aimed to compare the cartilage transcriptome responses of a non-surgical, mechanically induced rupture of the anterior cruciate ligament (ACL) model and the surgical destabilisation of the medial meniscus (DMM) model. Methods Skeletally mature male C57Bl6 mice were subjected to either the non-surgical, mechanical ACL rupture or surgical DMM models and transcriptome profiling performed on micro-dissected cartilage at day 7 and 42 post-procedure, respectively; in general, naïve animals served as controls. MicroRNA profiling was also performed on the ACL rupture model. Expression levels of a miRNA of interest, miR-199-5p, were inhibited in primary human articular chondrocytes (HAC) with RNA-seq and 3’UTR assays used to identify and valid potential target genes. Results The number of differentially expressed genes between the two models were comparable and highly correlative (Spearman R =0.8, P<2.2E-16). Gene ontology enrichment analysis identified similarly enriched pathways, containing anabolic terms including ‘extracellular matrix organisation’ enriched for the upregulated genes. Within the ACL rupture miRNA transcriptome, miR-199-5p family members were amongst the most abundantly, and differentially expressed, which was replicated in the DMM cartilage by qRT-PCR. Inhibition of miR-199-5p in HAC led to a comparable transcriptome response to that observed in both human OA damaged vs intact cartilage and murine DMM cartilage datasets. Several genes, including GIT1, NCEH1, SOS2 and ECE1 were all experimentally verified as targets. Conclusion For the first time, we have characterised both the mRNA and miRNA articular cartilage signature in the ACL rupture model and demonstrated highly correlative responses with the DMM PTOA model. These data support the use of the ACL rupture model as a non-invasive alternative to DMM.
Project description:Objective Animal models of post-traumatic osteoarthritis (PTOA) recapitulate the pathological changes observed in human PTOA. Here we aimed to compare the cartilage transcriptome responses of a non-surgical, mechanically induced rupture of the anterior cruciate ligament (ACL) model and the surgical destabilisation of the medial meniscus (DMM) model. Methods Skeletally mature male C57Bl6 mice were subjected to either the non-surgical, mechanical ACL rupture or surgical DMM models and transcriptome profiling performed on micro-dissected cartilage at day 7 and 42 post-procedure, respectively; in general, naïve animals served as controls. MicroRNA profiling was also performed on the ACL rupture model. Expression levels of a miRNA of interest, miR-199-5p, were inhibited in primary human articular chondrocytes (HAC) with RNA-seq and 3’UTR assays used to identify and valid potential target genes. Results The number of differentially expressed genes between the two models were comparable and highly correlative (Spearman R =0.8, P<2.2E-16). Gene ontology enrichment analysis identified similarly enriched pathways, containing anabolic terms including ‘extracellular matrix organisation’ enriched for the upregulated genes. Within the ACL rupture miRNA transcriptome, miR-199-5p family members were amongst the most abundantly, and differentially expressed, which was replicated in the DMM cartilage by qRT-PCR. Inhibition of miR-199-5p in HAC led to a comparable transcriptome response to that observed in both human OA damaged vs intact cartilage and murine DMM cartilage datasets. Several genes, including GIT1, NCEH1, SOS2 and ECE1 were all experimentally verified as targets. Conclusion For the first time, we have characterised both the mRNA and miRNA articular cartilage signature in the ACL rupture model and demonstrated highly correlative responses with the DMM PTOA model. These data support the use of the ACL rupture model as a non-invasive alternative to DMM.
Project description:Objective Animal models of post-traumatic osteoarthritis (PTOA) recapitulate the pathological changes observed in human PTOA. Here we aimed to compare the cartilage transcriptome responses of a non-surgical, mechanically induced rupture of the anterior cruciate ligament (ACL) model and the surgical destabilisation of the medial meniscus (DMM) model. Methods Skeletally mature male C57Bl6 mice were subjected to either the non-surgical, mechanical ACL rupture or surgical DMM models and transcriptome profiling performed on micro-dissected cartilage at day 7 and 42 post-procedure, respectively; in general, naïve animals served as controls. MicroRNA profiling was also performed on the ACL rupture model. Expression levels of a miRNA of interest, miR-199-5p, were inhibited in primary human articular chondrocytes (HAC) with RNA-seq and 3’UTR assays used to identify and valid potential target genes. Results The number of differentially expressed genes between the two models were comparable and highly correlative (Spearman R =0.8, P<2.2E-16). Gene ontology enrichment analysis identified similarly enriched pathways, containing anabolic terms including ‘extracellular matrix organisation’ enriched for the upregulated genes. Within the ACL rupture miRNA transcriptome, miR-199-5p family members were amongst the most abundantly, and differentially expressed, which was replicated in the DMM cartilage by qRT-PCR. Inhibition of miR-199-5p in HAC led to a comparable transcriptome response to that observed in both human OA damaged vs intact cartilage and murine DMM cartilage datasets. Several genes, including GIT1, NCEH1, SOS2 and ECE1 were all experimentally verified as targets. Conclusion For the first time, we have characterised both the mRNA and miRNA articular cartilage signature in the ACL rupture model and demonstrated highly correlative responses with the DMM PTOA model. These data support the use of the ACL rupture model as a non-invasive alternative to DMM.