Synovium and Infrapatellar fat pad are one functional tissue unit sharing common mesenchymal progenitors and undergoing coordinated changes in osteoarthritis

The Infrapatellar fat pads (IFP) are two wedge shaped fatty structures situated below the kneecap (patella), lying either side of the patellar tendon, first described by Hoffa in 1904. Recent studies reveal that knee OA causes pathological fibrosis, stiffening, and inflammation of the synovium and IFP (4, 5) (6). Multiple groups, including our co-investigator Dr. Changhai Ding, reported that MRI signal intensity alteration in IFP is strongly associated with OA knee structural abnormalities and may serve as an imaging biomarker to predict OA progression in patients (7-10). However, we have limited knowledge regarding the regulation of synovium and IFP functions for joint homeostasis and OA development. cell atlas of mouse synovium cells during DMM induced OA process髌下脂肪垫（Infrapatellar fat pads, IFP）是位于髌骨（patella）下方的一对楔形脂肪结构，分别排布于髌腱（patellar tendon）的两侧，于1904年由Hoffa首次描述。近期研究表明，膝关节骨关节炎（Osteoarthritis, OA）可诱导滑膜与髌下脂肪垫发生病理性纤维化、僵硬及炎症反应（4,5,6）。包括本研究共同研究者丁长海博士在内的多个研究团队已证实，髌下脂肪垫的磁共振成像（Magnetic Resonance Imaging, MRI）信号强度改变与膝关节骨关节炎的结构异常显著相关，可作为预测患者骨关节炎进展的成像生物标志物（7-10）。然而，目前学界对于滑膜与髌下脂肪垫在关节稳态及骨关节炎发生发展中的调控机制仍所知有限。本数据集对应内侧半月板失稳术（destabilization of the medial meniscus, DMM）诱导的骨关节炎进程中小鼠滑膜细胞的细胞图谱。