INPP5D modulates TREM2 loss-of-function phenotypes in a β-amyloidosis mouse model

We crossed Tyrobp-deficient and Inpp5d-deficient mice with App(NL-G-F/NL-G-F) Alzheimer model mice (hereafter, NLGF) and generate Tyrobp-/-;Inpp5d+/-;NLGF mice to assess the role of Inpp5d in Tyrobp-/- mice. We isolated microglia from NLGF, Tyrobp-/-;NLGF, and Tyrobp-/-;Inpp5d+/-;NLGF mice and analyzed microglial transcriptome using RNA-sequencing. Tyrobp-/- microglia showed substantially different transcriptome compared with NLGF microglia. Previously described "disease asscociated microglia" genes were enriched in the differentially expressed genes in Tyrobp-/- microglia. On the other hand, Tyrobp-/-;Inpp5d+/-;NLGF microglia showed similar transcriptome to Tyrobp-/- microglia except several genes (e.g., Wdfy1, Mamdc2, Klrb1f). These data suggest Inpp5d modulates microglial functions without affecting disease associated microglial gene expression in Tyrobp-/-;NLGF micrglia. Microglial transcriptome of 9-month-old NLGF (N=3), Inpp5d+/-;NLGF (N=3), Tyrobp-/-;NLGF (N=2), Tyrobp-/-;Inpp5d+/-;NLGF (N=3) mice. CD11b+/CD45+ live cells were collected as microglia.

我们将Tyrobp缺陷型小鼠与Inpp5d缺陷型小鼠，与App(NL-G-F/NL-G-F)阿尔茨海默病模型小鼠（下称NLGF）进行杂交，构建得到Tyrobp-/-;Inpp5d+/-;NLGF小鼠，以评估Inpp5d在Tyrobp缺陷型小鼠中的作用。我们从NLGF、Tyrobp-/-;NLGF以及Tyrobp-/-;Inpp5d+/-;NLGF小鼠体内分离小胶质细胞（microglia），并通过RNA测序（RNA-sequencing）分析其转录组特征。结果显示，Tyrobp缺陷型小鼠的小胶质细胞转录组与NLGF小鼠小胶质细胞的转录组存在显著差异；此前已报道的疾病相关小胶质细胞（disease associated microglia）相关基因，在Tyrobp缺陷型小鼠小胶质细胞的差异表达基因中显著富集。与之相对，Tyrobp-/-;Inpp5d+/-;NLGF小鼠的小胶质细胞转录组与Tyrobp-/-;NLGF小鼠的小胶质细胞转录组整体相似，仅少数基因（如Wdfy1、Mamdc2、Klrbf1）存在表达差异。上述数据表明，在Tyrobp-/-;NLGF小鼠的小胶质细胞中，Inpp5d可调控小胶质细胞功能，但不会影响疾病相关小胶质细胞的基因表达。本数据集包含9月龄NLGF（样本量N=3）、Inpp5d+/-;NLGF（N=3）、Tyrobp-/-;NLGF（N=2）以及Tyrobp-/-;Inpp5d+/-;NLGF（N=3）小鼠的小胶质细胞转录组数据；实验中通过分选CD11b+/CD45+活细胞作为小胶质细胞样本。