Single-cell RNA-seq analysis identifies meniscus progenitors and reveals the progression of meniscus degeneration

Abstract

ObjectivesThe heterogeneity of meniscus cells and the mechanism of meniscus degeneration is not well understood. Here, single-cell RNA sequencing (scRNA-seq) was used to identify various meniscus cell subsets and investigate the mechanism of meniscus degeneration.MethodsscRNA-seq was used to identify cell subsets and their gene signatures in healthy human and degenerated meniscus cells to determine their differentiation relationships and characterise the diversity within specific cell types. Colony-forming, multi-differentiation assays and a mice meniscus injury model were used to identify meniscus progenitor cells. We investigated the role of degenerated meniscus progenitor (DegP) cell clusters during meniscus degeneration using computational analysis and experimental verification.ResultsWe identified seven clusters in healthy human meniscus, including five empirically defined populations and two novel populations. Pseudotime analysis showed endothelial cells and fibrochondrocyte progenitors (FCP) existed at the pseudospace trajectory start. Melanoma cell adhesion molecule ((MCAM)/CD146) was highly expressed in two clusters. CD146+ meniscus cells differentiated into osteoblasts and adipocytes and formed colonies. We identified changes in the proportions of degenerated meniscus cell clusters and found a cluster specific to degenerative meniscus with progenitor cell characteristics. The reconstruction of four progenitor cell clusters indicated that FCP differentiation into DegP was an aberrant process. Interleukin 1β stimulation in healthy human meniscus cells increased CD318+ cells, while TGFβ1 attenuated the increase in CD318+ cells in degenerated meniscus cells.ConclusionsThe identification of meniscus progenitor cells provided new insights into cell-based meniscus tissue engineering, demonstrating a novel mechanism of meniscus degeneration, which contributes to the development of a novel therapeutic strategy.

Human engineered meniscus transcriptome after short-term combined hypoxia and dynamic compression

“…Different injuries could affect the progenitor cell proportion within the harvested meniscus specimen with downstream effects on the matrix-forming capacity of isolated cells. [23][24][25][26][27] Although MFCs may be the most attractive cell type for meniscus tissue engineering applications, 28 it is a challenge that their matrix-forming outcomes may depend upon uncontrollable factors such as the nature of the injury and the recruitment of local stem cell progenitors. [29][30][31][32] Candidate gene biomarkers of the human inner avascular meniscus have been characterized relative to expanded and re-differentiated MFCs.…”

Transcriptome Sequencing Reveals Sex Differences in Human Meniscal Cell Response to Estrogen Based on Dosing Kinetics

“…A number of microarray and sequencing studies have provided important insight on transcriptome differences in the meniscus including avascular meniscus that heals poorly, 39 in meniscus from patients with and without osteoarthritis, 40 the progenitor cell phenotype that may reduce osteoarthritis, 41 and single-cell sequencing to define unique meniscal progenitor populations that are critical to maintain tissue health and reduce degeneration. 42 Building off this body of work, this study focuses on transcriptome differences between male and female tissue that will inform sex differences in natural aging and inform the role of sex hormones in repair and homeostasis.…”

Single cell transcriptome analysis of decidua macrophages in normal and recurrent spontaneous abortion patients

“…The SCENIC analysis was run on the cells that passed the filtering, using the 20 thousand motifs database for RcisTarget and GRNboost, as previously described (Sun et al, 2020).…”