Dataset Information

Transcriptomic analyses of joint tissues during osteoarthritis development in a rat model reveal dysregulated mechanotransduction and extracellular matrix pathways

ABSTRACT: Transcriptomic changes in joint tissues during the development of osteoarthritis (OA) are of interest for the discovery of biomarkers and mechanisms of disease. The objective of this study was to use the rat medial meniscus transection (MMT) model to discover stage and tissue-specific transcriptomic changes. Sham or MMT surgeries were performed in mature rats. Cartilage, menisci and synovium were scored for histopathological changes at 2, 4 and 6 weeks post-surgery and processed for RNA-sequencing. Differentially expressed genes (DEG) were used to identify pathways and mechanisms. Published transcriptomic datasets from animal models and human OA were used to confirm and extend present findings. The total number of DEGs was already high at 2 weeks (723 in meniscus), followed by cartilage (259) and synovium (42) and declined to varying degrees in meniscus and synovium but increased in cartilage at 6 weeks. The most upregulated genes included tenascins. The 'response to mechanical stimulus' and extracellular matrix-related pathways were enriched in both cartilage and meniscus. Pathways that were enriched in synovium at 4 weeks indicate processes related to synovial hyperplasia and fibrosis. Synovium also showed upregulation of IL-11 and several MMPs. The mechanical stimulus pathway included upregulation of the mechanoreceptors PIEZO1, PIEZO2 and TRPV4 and nerve growth factor. Analysis of data from prior RNA-sequencing studies of animal models and human OA support these findings. These results indicate several shared pathways that are affected during OA in cartilage and meniscus and support the role of mechanotransduction and other pathways in OA pathogenesis.

ORGANISM(S): Rattus norvegicus

PROVIDER: GSE241794 | GEO | 2023/08/29

REPOSITORIES: GEO

ACCESS DATA

Similar Datasets

Project description:Background: Meniscus tears are the most common injury in the knee and are associated with an increased risk of osteoarthritis (OA). The molecular profile of knees with meniscus tears is not well-studied. Therefore, to advance our understanding of the early response of the knee to injury, we compared the gene expression profile of meniscus and articular cartilage within the same knees following meniscus injury. Hypothesis/Purpose: To identify differences between the molecular signatures of meniscus and articular cartilage from knees with intact articular cartilage undergoing arthroscopic partial meniscectomy. Study Design: Descriptive laboratory study Methods: Patients (n=12) with a known isolated medial meniscus tear without any knee chondrosis or radiographic OA were consented prior to surgery. During arthroscopic partial meniscectomy, a sample of their injured meniscus and a sample of their articular cartilage off the medial femoral condyle were procured. The transcriptome signatures, as measured through Affymetrix microarray, were compared between the two tissues and underlying biological processes were explored computationally. Results: 3566 gene transcripts were differentially expressed between meniscus and articular cartilage. Gene transcripts down-regulated in articular cartilage were associated with extracellular matrix organization, wound healing, cell adhesion, and chemotaxis. Gene transcripts up-regulated in articular cartilage were associated with blood vessels morphogenesis and angiogenesis. Examples of individual genes with significant differences in expression between the two tissues include IBSP (23.76 fold; P < 0.001), upregulated in meniscus, and TREM1 (3.23 fold; P = 0.006), upregulated in meniscus. Conclusion: The meniscus and articular cartilage have distinct gene expression profiles in knees with meniscus tears and intact articular cartilage. Total RNA obtained from injured meniscus and normal articular cartilage from patients undergoing partial meniscectomy.

Project description:Mechanical Stimuli are arguably the most important aetiolgical factors in osteoarthritis (OA) development. Not only do we see disease arising from joints where the cartilage has sustained direct (e.g. intraarticular fracture) or indirect (e.g. meniscal injury) trauma, but mechanical factors are considered, at least partly, to explain the disease associations with aging and obesity. It is now well established that OA is not simply due to repeated wear and tear, leading to attrition of the articular surfaces, but that it requires activation of a number of inflammatory genes, which drive catabolic protease activity in the joint. These enzymes lead to breakdown of the major extracellular matrix components of cartilage, namely type II collagen, and the proteoglycan, aggrecan. Although it is unclear precisely which enzymes are responsible for matrix breakdown in human OA, Glasson et al showed that deletion of the aggrecan degrading enzyme, ADAMTS5 substantially protected the joint from surgically induced murine OA suggesting that it is a major aggrecanase in the mouse. This study was part of a wider study using the surgical model of murine OA, induced by destabilising the medial meniscus (DMM), to confirm the dependence of joint loading on disease progression and to reveal mechanosensitive genes within the joint which may be involved in the development of OA. Using this model we, and others, have shown that there is a robust degradation of articular cartilage over 4-12wks in male C57B/6 mice. We identified the gene response in joints early following induction of OA, prior to cartilage degradation, by extracting RNA from whole joints (after skin and muscle had been removed) 6hrs, 3 days and 7 days following sham and DMM surgery. An Affymetrix ST1 gene array was performed. Significantly regulated genes (>1.4 fold above naive and sham samples at any timepoint), or those considered to have a putative role in OA pathogenesis were selected for quantitative validation using Taqman low density microfluidic card arrays (TLDA). Gene expression in whole knee joints at 3 early time points post DMM surgery (before cartilage loss), 6hrs, 3days and 7days was examined. Two controls were identified, the first control consisted of age matched naïve mice that had undergone 15 minutes of anaesthesia but were not operated on (0hrs post surgery). The second control included mice which had undergone sham surgery (capsulotomy alone). For this RNA was taken at the same time points post surgery as DMM samples (6hrs, 3days and 7days). There were three biological replicates per condition (total of 21 samples). The right (ipsilateral) knee joint was taken and RNA extracted and processed for microarray analysis using the Affymetrix Mouse Gene 1.0 st v1 platform.

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.

Dataset Information

Transcriptomic analyses of joint tissues during osteoarthritis development in a rat model reveal dysregulated mechanotransduction and extracellular matrix pathways

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure