The Expression profile of splenic/hepatic macrophages in RNaseT2 deficient mice

RNA stress caused by the loss of RNaseT2, which is localized in lysosomes, leads to macrophage accumulation in the spleen and liver. However, the underlying mechanism remained unclear. Here, we demonstrated that cell proliferation in Rnaset2 -/- mice is dependent on TLR13, an RNA sensor. In both organs, TLR13 was found to induce cell proliferation and survival signals. Notably, in the liver, the most accumulated Ly6Clow macrophages were found to resemble wild-type Kupffer cells. These cells were shown to exert hepatoprotective effects through the LXR-CD5L axis. To examine the characteristics of splenic macrophages that accumulate in Rnaset2–/– mice, we isolated Ly6C low or Ly6C high splenic macrophages from wild-type and Rnaset2–/– mice using FACS sorting. Similarly, to examine the characteristics of hepatic macrophages that accumulate in Rnaset2–/– mice, we isolated Kupffer cells, Ly6C low or Ly6C high splenic macrophages from wild-type and Rnaset2–/– mice using FACS sorting. Subsequently, we performed gene expression profiling analysis by employing RNA-seq data obtained from macrophage samples.

定位于溶酶体（lysosomes）的核糖核酸酶T2（RNaseT2）缺失所引发的RNA应激，会导致巨噬细胞在脾脏与肝脏中聚集。然而其背后的分子机制尚未阐明。本研究证实，RNaseT2敲除（Rnaset2⁻/⁻）小鼠的细胞增殖依赖于RNA感受器（RNA sensor）Toll样受体13（TLR13）。在上述两个器官中，TLR13均可诱导细胞增殖与存活信号通路的激活。值得注意的是，在肝脏中大量聚集的Ly6C低表达巨噬细胞，其表型与野生型库普弗细胞（Kupffer cells）相似。这类细胞可通过肝X受体-CD5L（LXR-CD5L）信号轴发挥肝脏保护作用。为探究RNaseT2敲除小鼠脾脏中聚集的巨噬细胞的特征，我们通过荧光激活细胞分选术（FACS sorting），从野生型与RNaseT2敲除小鼠体内分离得到Ly6C低表达与高表达的脾脏巨噬细胞。同理，为探究RNaseT2敲除小鼠肝脏中聚集的巨噬细胞的特征，我们同样通过荧光激活细胞分选术，从野生型与RNaseT2敲除小鼠体内分离得到库普弗细胞、Ly6C低表达与高表达的脾脏巨噬细胞。随后，我们利用巨噬细胞样本的RNA测序（RNA-seq）数据，开展了基因表达谱分析。