Infrapatellar Fat Pad and Knee Osteoarthritis Zeng Ni

Infrapatellar Fat Pad and Knee Osteoarthritis Zeng Ni, Yan Zhi-Peng, Chen Xin-Yuan, Ni Guo-Xin 1 School of Sport Medicine and Rehabilitation, Beijing Sport University, Beijing, China 2 Department of Rehabilitation Medicine, The First Affiliated Hospital of Fujian Medical University, Fuzhou, China Figure 1. A mechanistic model depicting how IFP is involved in OA pathogenesis. It is supposed that the IFP may be involved in the local inflammation state and/or that it might interact with other periarticular tissues, thus contributing to the development of KOA. (A). IFP may interact with cartilage, synovial membrane and subchondral bone. IFP may interact with the synovial tissue through affecting the inflammatory response and promoting the Aging and Disease, 2020, 11(5), 1317 -1328. DOI: 10. 14336/AD. 2019. 1116 fibrosis of the synovial cells. In parallel, IFP plays either a deleterious or a protective role on cartilage by altering the expression of IL-6 or leptin or MMPs. While the influence of IFP on subchondral bone has not yet been investigated clear, IFP may interact with subchondral bone through Wnt signaling pathway. Reciprocally, these joint tissues could also modulate the IFP. (B). Many factors such as obesity, bone fracture, and aging are related to abnormal loading or abnormal cartilage, and eventually lead to cartilage injury. Then, the immune response of IFP may be activated by the cartilage specific autoantigens. The immunophenotype of immune cells of IFP is related to inflammatory phenotype of IFP, which is the potential mechanisms of the involvement of IFP in the