scRNA-seq reveals cellular heterogeneity from deep fascia in patients with aute compartment syndrome

Abstract:Introduction:High stress in the compartment surrounded by the deep fascia may cause acute compartment syndrome (ACS) that may result in extremity necrosis. The aim of this study is to investigate the the cellular heterogeneity of the deep fascia under high stress in the compartment by single-cell RNA sequencing (scRNA-seq).Methods: Finally, deep fascia samples were collected from patients with blisters after tibiofibular fracture as the high-stress group (HG, n=3) and from patients with osteosarcoma who underwent thigh amputation as the normal-stress group (NG, n=3)We utilized ultrasound and scanning electron microscopy to observe the morphologic change of deep fascia under high stress, used multiplex staining and multispectral imaging to explore immune cell infiltration, and applied scRNA-seq to investigate the cellular heterogeneity of the deep fascia and identify differential expressed genes.Results: Notably, we identified GZMK+interferon-act CD4 central memory T cells as a specific high-stress compartment subcluster expressing interferon-related genes. Additionally, the changes in the proportions of inflammation-related subclusters, such as increased proportions of M2 macrophages and decreased proportions of M1 macrophages, may indicate a crucial role of the balance of proinflammatory and anti-inflammatory in the development of ACS. Furthermore, we found that heat shock protein genes were upregulated and metal ion-related genes (S100 family and metallothionein family genes) were downregulated in numerous subpopulations under high stress.Conclusions: We identified a high stress-specific subcluster and variations in immune cells and fibroblast subclusters, as well as their differential expressed genes under high stress in the compartment. Our findings reveal the functions of the deep fascia and elucidate the pathophysiology of ACS, providing new approaches for its treatment and prevention.