Single cell multiome analysis of mouse achilles tendon

Tendons are fibrous tissues that connect bones to muscles. It is believed that tendons mature after birth through exercise and load-bearing activities. During this process, tendon cells are thought to be essential for tendon maturation by producing collagen and extracellular matrix components through the activation of master transcription factors such as Mkx and Scx. To investigate this, Achilles tendons from 2-week-old and 6-week-old mice were analyzed using single-cell RNA sequencing and single-nuclei ATAC sequencing to compare the transitions in cell populations and changes in gene expression between immature and mature tendons. Furthermore, the study aimed to identify tendon progenitor cells, which are thought to be more abundant in immature tendon tissue, and to search for useful marker genes for detecting these cell populations.

肌腱（tendon）是连接骨骼与肌肉的纤维结缔组织。学界普遍认为，肌腱在出生后通过运动与负重活动完成成熟过程。在此进程中，肌腱细胞被认为是肌腱成熟的关键介导因子：其可通过激活Mkx、Scx等主转录因子，合成胶原蛋白与细胞外基质组分，从而推动肌腱成熟。为探究该机制，研究团队对2周龄与6周龄小鼠的跟腱（Achilles tendon）开展了单细胞RNA测序（single-cell RNA sequencing）与单细胞核ATAC测序（single-nuclei ATAC sequencing），以对比未成熟与成熟肌腱的细胞群体动态变化及基因表达差异。此外，本研究还旨在鉴定在未成熟肌腱组织中富集度更高的肌腱祖细胞（tendon progenitor cell），并筛选可用于识别这类细胞群体的特异性标记基因。