Lu Zhimin, Ding Ling, Zhang Sen, Jiang Xing, Ma Wen, Liu Youhan, Tian Xuewen, Wang Qinglu
College of Sport and Health, Shandong Sport University, Jinan, 250102, Shandong, China.
College of Management, Qilu Medical University, Zibo, 250300, Shandong, China.
Eur J Med Res. 2025 Aug 5;30(1):708. doi: 10.1186/s40001-025-02978-6.
Obesity alters the adipose tissue (AT) immune microenvironment (TIME) and induces inflammation. Nevertheless, the specific time when TIME dysfunction emerges in AT remains elusive. Obesity mouse models were constructed and categorized into Lean (Ctrl), moderately obese (Mid_Ob, with body weight exceeding Ctrl by > 10%), and Obese (Ob, with body weight exceeding Ctrl by > 20%) groups. Single-nucleus RNA sequencing (snRNA-seq) and immunofluorescence localization were employed to analyze changes in cell populations, cluster marker genes, and signaling pathways in mouse epididymal white adipose tissue (eWAT). A total of 23,068 cells obtained from three mouse eWAT samples (Ctrl, Mid_Ob, and Ob) underwent snRNA-seq. Eighteen distinct clusters were identified, and seven cell types were annotated with representative markers. In-depth analysis unveiled the functions of the adipose AT-associated Krt23+fibroblast (ATAKF) cell subtype and refined the crosstalk hypothesis concerning ATAKFs, macrophages, and neutrophils. We further demonstrated that ATAKFs were present in the Mid_Ob group. Additionally, from the Mid_Ob to Ob stage, AT inflammatory factors, macrophages, and neutrophils significantly increased while neurons markedly decreased; however, these factors did not change significantly from the Ctrl to Mid_Ob stage. Cell-cell communication analysis revealed the central role of ATAKFs and their regulation of macrophages and neutrophils. Only when obesity reaches the Mid_Ob stage AT fibroblasts specifically express Krt23+, recruit neutrophils, and secrete CCL2, CCL6, and CCL9 to attract macrophages, thereby altering the eWAT TIME. ATAKFs contribute to immune microenvironment disorders during the development of mouse AT obesity. This study offers valuable resources and a foundation for understanding the timing of TIME dysfunction.
肥胖会改变脂肪组织（AT）的免疫微环境（TIME）并引发炎症。然而，AT中TIME功能障碍出现的具体时间仍不清楚。构建肥胖小鼠模型并将其分为瘦型（对照）、中度肥胖（Mid_Ob，体重超过对照>10%）和肥胖（Ob，体重超过对照>20%）组。采用单核RNA测序（snRNA-seq）和免疫荧光定位分析小鼠附睾白色脂肪组织（eWAT）中细胞群体、簇标记基因和信号通路的变化。从三只小鼠的eWAT样本（对照、Mid_Ob和Ob）中获得的总共23,068个细胞进行了snRNA-seq分析。鉴定出18个不同的簇，并使用代表性标记注释了7种细胞类型。深入分析揭示了脂肪AT相关的Krt23+成纤维细胞（ATAKF）细胞亚型的功能，并完善了关于ATAKFs、巨噬细胞和中性粒细胞的串扰假说。我们进一步证明ATAKFs存在于Mid_Ob组中。此外，从中度肥胖到肥胖阶段，AT炎症因子、巨噬细胞和中性粒细胞显著增加，而神经元明显减少；然而，从对照到中度肥胖阶段，这些因子没有显著变化。细胞间通讯分析揭示了ATAKFs的核心作用及其对巨噬细胞和中性粒细胞的调节。只有当肥胖达到中度肥胖阶段时，AT成纤维细胞才特异性表达Krt23+，募集中性粒细胞，并分泌CCL2、CCL6和CCL9以吸引巨噬细胞，从而改变eWAT的TIME。ATAKFs在小鼠AT肥胖发展过程中导致免疫微环境紊乱。本研究为理解TIME功能障碍的发生时间提供了有价值的资源和基础。
