Eur Cell Mater. 2022 Aug 2;44:1-20. doi: 10.22203/eCM.v044a01.
Chronic tendinopathy represents a growing healthcare burden in the ageing global population. Curative therapies remain elusive as the mechanisms that underlie chronic inflammation in tendon disease remain unclear. Identifying and isolating key pathogenic and reparative cells is essential in developing precision therapies and implantable materials for improved tendon healing. Multiple discrete human tendon cell populations have been previously described ex vivo. To determine if these populations persist in vitro, healthy human hamstring tenocytes were cultured for 8 d on either tissue culture plastic or aligned electrospun fibres of absorbable polydioxanone. Novel single-cell surface proteomics combined with unbiased single-cell transcriptomics (CITE-Seq) was used to identify discrete tenocyte populations. 6 cell populations were found, 4 of which shared key gene expression determinants with ex vivo human cell clusters: PTX3_PAPPA, POSTN_SCX, DCN_LUM and ITGA7_NES. Surface proteomics found that PTX3_PAPPA cells were CD10+CD26+CD54+. ITGA7_NES cells were CD146+ and POSTN_SCX cells were CD90+CD95+CD10+. Culture on the aligned electrospun fibres favoured 3 cell subtypes (DCN_LUM, POSTN_SCX and PTX3_ PAPPA), promoting high expression of tendon-matrix-associated genes and upregulating gene sets enriched for TNF-a and IL-6/STAT3 signalling. Discrete human tendon cell subpopulations persisted in in vitro culture and could be recognised by specific gene and surface-protein signatures. Aligned polydioxanone fibres promoted the survival of 3 clusters, including pro-inflammatory PTX3-expressing CD10+CD26+CD54+ cells found in chronic tendon disease. These results improved the understanding of preferred culture conditions for different tenocyte subpopulations and informed the development of in vitro models of tendon disease.
慢性肌腱病代表着全球老龄化人口中日益增长的医疗保健负担。由于肌腱疾病中慢性炎症的发生机制仍不清楚，因此仍难以找到有效的治疗方法。鉴定和分离关键的致病和修复细胞对于开发用于改善肌腱愈合的精准治疗方法和可植入材料至关重要。先前已经在体外描述了多种离散的人类肌腱细胞群体。为了确定这些群体是否在体外持续存在，将健康的人类腘绳肌腱细胞在组织培养塑料或可吸收的聚二恶烷酮的对齐电纺纤维上培养 8 天。使用新的单细胞表面蛋白质组学结合无偏单细胞转录组学（CITE-Seq）来鉴定离散的肌腱细胞群体。发现了 6 种细胞群，其中 4 种与体外人类细胞簇具有关键基因表达决定因素：PTX3_PAPPA、POSTN_SCX、DCN_LUM 和 ITGA7_NES。表面蛋白质组学发现，PTX3_PAPPA 细胞为 CD10+CD26+CD54+。ITGA7_NES 细胞为 CD146+，POSTN_SCX 细胞为 CD90+CD95+CD10+。在对齐的电纺纤维上培养有利于 3 种细胞亚型（DCN_LUM、POSTN_SCX 和 PTX3_ PAPPA），促进与肌腱基质相关基因的高表达，并上调富含 TNF-a 和 IL-6/STAT3 信号的基因集。离散的人类肌腱细胞亚群在体外培养中持续存在，并且可以通过特定的基因和表面蛋白特征来识别。对齐的聚二恶烷酮纤维促进了 3 个簇的存活，包括在慢性肌腱病中发现的表达 PTX3 的 CD10+CD26+CD54+促炎细胞。这些结果提高了对不同肌腱细胞亚群的优选培养条件的理解，并为肌腱病的体外模型的开发提供了信息。
