Single Cell RNA-Sequence Analyses Reveal Uniquely Expressed Genes and Heterogeneous Immune Cell Involvement in the Rat Model of Intervertebral Disc Degeneration

作者：Milad Rohanifar, Sade W. Clayton, Garrett W. D. Easson, Sumersing Patil, Frank Lee, Liufang Jing, Marcos N. Barcellona, Julie E. Speer, Jordan J. Stivers, Simon Y. Tang, Lori A. Setton · 发表于：bioRxiv (Cold Spring Harbor Laboratory) · 年份：2022 · DOI：10.1101/2022.07.05.498865 · 被引用次数：5 · 研究领域：Spine and Intervertebral Disc Pathology、Musculoskeletal pain and rehabilitation、Spondyloarthritis Studies and Treatments

ABSTRACT Intervertebral disc (IVD) degeneration is characterized by a loss of cellularity, and changes in cell-mediated activity that drives anatomic changes to IVD structure. In this study, we use single cell RNA-sequencing analysis of cells extracted from the degenerating tissues of the rat IVD following lumbar disc puncture. Two control, uninjured IVDs (L2-3, L3-4) and two degenerated, injured IVDs (L4-5, L5-6) from each animal were examined either at two- and eight-week post-operative time points. The cells from these IVDs were extracted and transcriptionally profiled at a single-cell resolution. Unsupervised cluster analysis revealed the presence of 4 known cell types in both non-degenerative and degenerated IVDs based on previously established gene markers: IVD cells, endothelial cells, myeloid cells, and lymphoid cells. As a majority of cells were associated with the IVD cell cluster, sub-clustering was used to further identify the cell populations of the nucleus pulposus, inner and outer annulus fibrosus. The most notable difference between control and degenerated IVDs was the increase of myeloid and lymphoid cells in degenerated samples at 2- and 8- weeks post-surgery. Differential gene expression analysis revealed multiple distinct cell types from the myeloid and lymphoid lineages, most notably macrophages and B lymphocytes and demonstrated a high degree of immune specificity during degeneration. In addition to the heterogenous infiltrating immune cell populations i...