1. Academic Validation
  2. TGF-β/Alk5 signaling prevents osteoarthritis initiation via regulating the senescence of articular cartilage stem cells

TGF-β/Alk5 signaling prevents osteoarthritis initiation via regulating the senescence of articular cartilage stem cells

  • J Cell Physiol. 2021 Jul;236(7):5278-5292. doi: 10.1002/jcp.30231.
Qiaoyan Tan 1 Quan Wang 1 2 Liang Kuang 1 Jinfan Zhang 1 Xiuqin Peng 1 Sen Liang 1 Mi Liu 1 Hangang Chen 1 Shuai Chen 1 Xiaoqing Luo 1 Huabing Qi 1 Can Li 1 Fengtao Luo 1 Shuo Huang 1 Zhenhong Ni 1 Min Jin 1 Nan Su 1 Jing Yang 1 Peng Yang 1 Bo Chen 1 Liang Chen 1 Xiaolan Du 1 Yangli Xie 1 Lin Chen 1
Affiliations

Affiliations

  • 1 Department of Wound Repair and Rehabilitation Medicine, State Key Laboratory of Trauma, Burns and Combined Injury, Trauma Center, Research Institute of Surgery, Daping Hospital, Army Medical University, Chongqing, China.
  • 2 Radiation Oncology Center, Fifth Medical Center of Chinese PLA General Hospital, Beijing, China.
Abstract

Osteoarthritis (OA) is the most common joint disease. The surface of joint cartilage is a defensive and first affected structure of articular cartilage (AC) during the pathogenesis of OA. ALK5 signaling is critical for maintaining AC homeostasis, however, the role and underlying mechanism for the involvement of ALK5 signaling in the phenotypes of articular cartilage stem cells (ACSCs) at the surface of AC is still unclear. The role of ALK5 in OA development was explored using an ACSCs-specific Alk5-deficient (cKO) mouse model. Alterations in cartilage structure were evaluated histologically. Senescence was detected by SA-β-gal, while Reactive Oxygen Species (ROS), MitoTracker, and LysoTracker staining were used to detect changes related to senescence. In addition, mice were injected intra-articularly with ganciclovir to limit the detrimental roles of senescent cells (SnCs). ALK5 cKO mice showed a decreased number of the slow-cell cycle cells and less lubricant secretion at the surface accompanied with drastically accelerated cartilage degeneration under ageing and surgically induced OA conditions. Further studies showed that ALK5 deficient ACSCs exhibited senescence-like manifestations including decreased proliferation and differentiation, more SA-β-gal-positive cells and ROS production, as well as significantly swollen mitochondria and lysosome breakdown. We further found that local limitation of the detrimental roles of SnCs can attenuate the development of posttraumatic OA. Taken together, our findings suggest that ALK5 signaling acts as an important regulator of the SnCs in the superficial layer during AC maintenance and OA initiation.

Keywords

Alk5; articular cartilage stem cells; osteoarthritis; senescence.

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