Fig 2: Single‐cell atlas of mechanical strain‐related enthesitis in an ankylosing spondylitis (AS) model. (A) Processing pipeline of single‐cell RNA sequencing of Achilles tendon entheses from SKG mice under nontail suspension (NTS)/tail suspension (TS) conditions. (B) The incidence rate in SKG mice under TS conditions was lower than that in SKG mice under NTS conditions before Day 15. The mean arthritis score, as well as that of the fore paws and hind paws, was lower in the TS group (n = 10) than in the NTS group (n = 10). (C) The degree of swelling, number of syndesmophytes detected by micro‐CT and severity of inflammatory infiltration detected by HE staining in the entheses were alleviated in the TS group (Black and white arrows). Scale bar, 200 µm. (D) The scaled expression of marker genes for each cluster is shown as a heatmap. (E) T‐distributed stochastic neighbor embedding (t‐SNE) view of 10,312 cells from the NTS group and 13,316 cells from the TS group, color‐coded by the assigned cell type. (F) Proportion of each cell cluster in the NTS and TS groups. (G) The ratio of Ly6g+ neutrophils was lower and that of Pdgfra+ fibroblasts was greater on the tendon sheath side of the entheses in the TS group (n = 6) than in the NTS group (n = 6). S indicates the sheath side, and T indicates the tendon side. Scale bar, 50 µm. (H) Relative signal flow in the NTS and TS groups. Both the number and strength of signaling pathway interactions decreased in the TS group. (I) Dot plot showing the strengths of the incoming and outgoing signal interactions of each clustered cell type. (J) Heatmap showing the differential interaction strength of each clustered cell type of the TS groups compared to the NTS groups. The values are presented as the means ± SDs. * p < 0.05 and *** p < 0.001. Neu indicates neutrophils, Mono‐macro indicates monocyte–macrophage, Fibro indicates fibroblasts, Proliferative indicates proliferative cells, and Endothelial indicates endothelial cells.