IntroductionTendinopathy, the most common form of chronic tendon disorder, leads to persistent tendon pain and loss of function. Profiling the heterogeneous cellular composition in the tendon microenvironment helps to elucidate rational molecular mechanisms of tendinopathy.Methods and resultsIn this study, through a multi-modal analysis, a single-cell RNA- and ATAC-seq integrated tendinopathy landscape was generated for the first time. We found that a specific cell subpopulation with lowPRDX2expression exhibited a higher level of inflammation, lower proliferation and migration ability, which not only promoted tendon injury but also led to microenvironment deterioration. Mechanistically, a motif enrichment analysis of chromatin accessibility showed thatFOXO1was an upstream regulator of PRDX2 transcription, and we confirmed that functional blockade ofFOXO1activity inducedPRDX2silencing. The TNF signaling pathway was significantly activated in thePRDX2-low group, and TNF inhibition effectively restored diseased cell degradation.DiscussionWe revealed an essential role of diseased cells in tendinopathy and proposed the FOXO1-PRDX2-TNF axis is a potential regulatory mechanism for the treatment of tendinopathy.