Integration of transcriptomic and epigenomic analyses uncovered Lrrc15 as a potential contributing factor to cartilage damage in osteoarthritis
Ontology highlight
ABSTRACT: 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.
ORGANISM(S): Mus musculus
PROVIDER: GSE175486 | GEO | 2021/09/01
REPOSITORIES: GEO
ACCESS DATA