Renal pericytes express phagocyte/macrophage-like function after kidney injury

我们已经发现，与对照肾脏相比，使用2肾1夹（2K1I）模型的缺血肾脏中表达的ng2阳性细胞（活化周细胞的标志）增加。此外，我们通过流式细胞术和免疫组织化学发现，部分ng2阳性细胞也表达CD11b或巨噬细胞标志物F4/80。此外，我们发现NG2/ cd11b阳性或NG2/ f4 /80阳性细胞的表达在缺血后第3天达到最高水平。接下来，我们从缺血肾脏中分离出ng2阳性细胞，并对荧光结合珠进行吞噬能力检测。我们发现一些ng2阳性的细胞也具有对微球的吞噬能力。研究表明，巨噬细胞的表型可以决定缺血后肾损伤的严重程度。巨噬细胞可分为炎性巨噬细胞M1和抗炎性巨噬细胞M2。因此，我们进一步采用real-time PCR检测ng2阳性细胞是否表达M1或M2巨噬细胞标志物。我们发现，与对照肾脏相比，从缺血肾脏分离的ng2阳性细胞表达了相似水平的TNF α和IL-6，这被称为M1标记物。相比之下，与对照组相比，从缺血肾中分离的ng2阳性细胞含有更高水平的甘露糖受体和IL-10，即M2标记物，这些结果表明，缺血肾中ng2阳性细胞含有M2巨噬细胞的表型。

We have identified that there is an increase in NG2-positive cells, a marker of activated pericyte, expressed in ischemic kidney using 2-kidney 1-clip (2K1I) model as compared to control kidney. Moreover, we discovered that a part of NG2-positive cells is also expressed CD11b or F4/80, a marker of macrophage, in ischemic kidney using flow cytometry and immunohistochemistry. Furthermore, we discovered that expression of NG2/CD11b-positive or NG2/F4/80-positive cells reached the highest level on day3 after ischemia. Next, we isolated NG2-positive cells from ischemic kidney and performed phagocytic ability against fluorescent-conjugated beads. We found that some of NG2-positive cells also contained phagocytic ability against the beads. It is established that phenotype of macrophage can determine severity of renal injury after ischemia. Macrophage can be divided into M1, known as inflammatory macrophage, and M2, known as anti inflammatory macrophage. Therefore, we further checked whether NG2-positive cells are expressed the markers of M1 or M2 macrophage using real-time PCR. We found that NG2-positive cells isolated from ischemic kidney expressed similar level of TNF alpha and IL-6, which is known as M1 markers, as compared to the control kidney. In contrast, NG2-positive cells isolated from ischemic kidney contained a higher level of mannose receptor and IL-10, which is known as M2 markers, as compared to the controls, These results suggest that NG2-positive cells in ischemic kidney contain phenotype of M2 macrophage.