The PI3K/AKT/mTOR signaling pathway in osteoarthritis: a narrative review

Osteoarthritis Cartilage. 2020 Apr;28(4):400-409. doi: 10.1016/j.joca.2020.02.027. Epub 2020 Feb 18.

Abstract

Osteoarthritis (OA) is a complicated degenerative disease that affects whole joint tissue. Currently, apart from surgical approaches to treat late stage OA, effective treatments to reverse OA are not available. Thus, the mechanisms leading to OA, and more effective approaches to treat OA should be investigated. According to available evidence, the PI3K/AKT/mTOR signaling pathway is essential for normal metabolism of joint tissues, but is also involved in development of OA. To provide a wide viewpoint to roles of PI3K/AKT/mTOR signaling pathway in osteoarthritis, a comprehensive literature search was performed using PubMed terms 'PI3K OR AKT OR mTOR' and 'osteoarthritis'. This review highlights the role of PI3K/AKT/mTOR signaling in cartilage degradation, subchondral bone dysfunction, and synovial inflammation, and discusses how this signaling pathway affects development of the disease. We also summarize recent evidences of therapeutic approaches to treat OA by targeting the PI3K/AKT/mTOR pathway, and discuss potential challenges in developing these strategies for clinical treatment of OA.

Keywords: AKT; Cartilage; Osteoarthritis; PI3K; mTOR.

Publication types

  • Research Support, Non-U.S. Gov't
  • Review

MeSH terms

  • Animals
  • Apoptosis
  • Autophagy
  • Bone and Bones / metabolism
  • Cartilage, Articular / metabolism
  • Cell Proliferation
  • Chondrocytes / metabolism
  • Humans
  • Mechanistic Target of Rapamycin Complex 1 / metabolism
  • Mechanistic Target of Rapamycin Complex 2 / metabolism
  • Mesenchymal Stem Cells
  • Osteoarthritis / metabolism*
  • Osteoblasts
  • Phosphatidylinositol 3-Kinases / metabolism*
  • Proto-Oncogene Proteins c-akt / metabolism*
  • Signal Transduction
  • Synovitis / metabolism
  • TOR Serine-Threonine Kinases / metabolism*

Substances

  • Mechanistic Target of Rapamycin Complex 1
  • Mechanistic Target of Rapamycin Complex 2
  • Proto-Oncogene Proteins c-akt
  • TOR Serine-Threonine Kinases