Single-cell RNA sequencing identifies Atf3+ senescent chondrocytes in the aged rat meniscus

we conducted single-cell RNA sequencing (scRNA-seq) analysis using the 10x Chromium platform to uncover the cellular composition and molecular profiles of meniscal cells from different age groups.The meniscus, a fibrocartilaginous structure essential for joint load distribution, is highly susceptible to age-related degeneration. With aging, the meniscus experiences structural and functional deterioration, contributing to the progression of osteoarthritis(OA). This study aims to bridge this gap by profiling the cellular landscape and analyzing age-related changes in the aging meniscus using scRNA-seq. Overall design: we conducted single-cell RNA sequencing (scRNA-seq) analysis using the 10x Chromium platform to uncover the cellular composition and molecular profiles of meniscal cells from different age groups Briefly, tissues were minced into ~1 mm³ pieces, digested with 4 mg/mL protease for 1 hour, followed by 0.25 mg/mL collagenase P for 4-6 hours. After washing with 0.04% bovine serum albumin (BSA) in phosphate-buffered saline (PBS), the cells were resuspended in 0.04% BSA and filtered through a 35 µm cell strainer. Viable cells were visually inspected, sorted via flow cytometry, and collected. Flow cytometry sorting ensured a viability threshold of >85% for single-cell RNA-seq