Dynamic analysis of mononuclear transcription profiles of fat in different parts of mice during aging

Adipose tissue shows significant changes during aging. Here, we used single-nucleus RNA-seq to map the single-nucleus transcription profiles of mouse subcutaneous adipose tissue ( SAT ) and visceral adipose tissue ( VAT ) at a single-nucleus resolution, showing the differences in visceral and subcutaneous adipose tissue changes with aging. The mononuclear sequencing method enabled us to restore all major cell types in mouse white adipose tissue, and we characterized adipocytes, immune cells, and preadipocytes. We demonstrated the existence of different adipocyte subsets and showed that aging leads to a decrease in adipogenic subsets. In addition, with aging, both subcutaneous adipose tissue and visceral adipose tissue showed a decrease in immune mechanisms. Subcutaneous mouse adipose tissue depots were dissected from 2 months and 26 months female C57BL/6J mice into ice-cold PBS. diluted in diethyl pyrocarbonate (DEPC) water White adipose tissue (SAT and VAT) was surgically removed and placed in 1x PBS on ice. Cells were then stained with desired antibodies, and subjected to FACS or snRNA-seq.脂肪组织在衰老过程中会发生显著变化。本研究采用单细胞核RNA测序（single-nucleus RNA-seq），以单细胞核分辨率绘制了小鼠皮下脂肪组织（subcutaneous adipose tissue, SAT）和内脏脂肪组织（visceral adipose tissue, VAT）的单细胞核转录组图谱，揭示了衰老过程中内脏与皮下脂肪组织的变化差异。该单细胞核测序技术得以完整还原小鼠白色脂肪组织中的所有主要细胞类群，并对脂肪细胞、免疫细胞以及前体脂肪细胞进行了分型鉴定。本研究证实了不同脂肪细胞亚群的存在，并发现衰老会导致成脂性亚群的占比下降。此外，随着衰老进程，小鼠皮下及内脏脂肪组织的免疫调控功能均出现显著衰退。我们从2月龄及26月龄的雌性C57BL/6J小鼠体内分离皮下脂肪组织块，将其置于预冷的磷酸盐缓冲液（PBS）中，并用焦碳酸二乙酯（DEPC）水进行稀释。随后手术取出白色脂肪组织（SAT与VAT），将其放置于冰上的1×PBS溶液内。之后使用目标抗体对细胞进行染色，进而通过流式细胞术分选（FACS）或单细胞核RNA测序开展后续实验。