Annulus fibrosus cell phenotypes in homeostasis and injury: implications for regenerative strategies. Issue 1 (14th September 2018)

• Record Type: Journal Article
• Authors: Torre, Olivia M.; Mroz, Victoria; Bartelstein, Meredith K.; Huang, Alice H.; Iatridis, James C.
• Editors: Sun, Hui B.
• Is Part Of: Annals of the New York Academy of Sciences. Volume 1442:Issue 1(2019)
• Page Start: 61
• Page End: 78
• Publication Date: 2018-09-14
• Subjects: annulus fibrosus -- intervertebral disk -- cell phenotype -- intervertebral disk injury models -- healing -- regeneration; Medical sciences -- Periodicals; Medicine -- Periodicals; Science -- Periodicals; 610
• DOI: 10.1111/nyas.13964
• Languages: English
• ISSNs: 0077-8923

Abstract

Abstract: Despite considerable efforts to develop cellular, molecular, and structural repair strategies and restore intervertebral disk function after injury, the basic biology underlying intervertebral disk healing remains poorly understood. Remarkably, little is known about the origins of cell populations residing within the annulus fibrosus, or their phenotypes, heterogeneity, and roles during healing. This review focuses on recent literature highlighting the intrinsic and extrinsic cell types of the annulus fibrosus in the context of the injury and healing environment. Spatial, morphological, functional, and transcriptional signatures of annulus fibrosus cells are reviewed, including inner and outer annulus fibrosus cells, which we propose to be referred to as annulocytes. The annulus also contains peripheral cells, interlamellar cells, and potential resident stem/progenitor cells, as well as macrophages, T lymphocytes, and mast cells following injury. Phases of annulus fibrosus healing include inflammation and recruitment of immune cells, cell proliferation, granulation tissue formation, and matrix remodeling. However, annulus fibrosus healing commonly involves limited remodeling, with granulation tissues remaining, and the development of chronic inflammatory states. Identifying annulus fibrosus cell phenotypes during health, injury, and degeneration will inform reparative regeneration strategies aimed at improving annulus fibrosus healing. Abstract : Despite considerable efforts to develop cellular, molecular, and structural repair strategies and restore intervertebral disc function after injury, the basic biology underlying intervertebral disc healing remains poorly understood. This review focuses on recent literature highlighting the intrinsic and extrinsic cell types of the annulus fibrosus in the context of the injury and healing environment, and describes the.spatial, morphological, functional, and transcriptional signatures of annulus fibrosus cells.