目的 探讨慢性束缚应激（CRS）对小鼠海马星形胶质细胞表型转换及抑郁样行为的影响。  方法 48只雄性C57BL/6小鼠随机分为对照组（control）、模型组（CRS）、氟西汀（FLX）药物干预组（CRS+FLX），每组各16只。慢性束缚应激3周建立抑郁小鼠模型，应激的第8天至第21天，CRS+FLX组于应激前30min腹腔注射FLX（10mg/kg），control组及CRS组注射等体积生理盐水。采用旷场实验以及糖水偏好实验检测各组小鼠行为变化；采用免疫组织化学法和Western blotting检测星形胶质细胞标记物胶质纤维酸性蛋白（GFAP）的表达；Real-time PCR检测海马A1和A2型星形胶质细胞标记物的表达。  结果 与control组相比，CRS组小鼠表现出明显的抑郁样行为，包括糖水偏好百分比显著降低（P＜0.0001），体重明显较低（P＜0.05），旷场实验在中央区域活动的距离明显降低（P＜0.0001），FLX干预可逆转CRS所诱导的抑郁样行为表现（P＜0.05）；与control组相比，CRS组小鼠海马星形胶质细胞标记物胶质纤维酸性蛋白（GFAP）表达明显上调（P＜0.05），而FLX可下调小鼠海马GFAP的表达（P＜0.05）； 与control组相比，CRS组小鼠海马区A1表型标记物［（H2D1、鸟苷酸结合蛋白2（GBP2）、Fk-506结合蛋白（FKBP5）、Amigo2）］mRNA表达水平上调(P＜0.05)，A2表型标志物mRNA水平无明显改变（P＞0.05）；FLX干预后可显著降低A1表型标志物mRNA表达水平（P＜0.05），对A2表型标志物mRNA表达水平无显著影响（P＞0.05）； 与control组相比，CRS组小鼠海马A1型标记物（C3、Fkbp5、GBP2）蛋白表达水平上调(P＜0.05)，A2型标记物CD14蛋白表达无明显改变（P=0.8361），FLX干预后可显著下调A1型标记物的蛋白水平（P＜0.05），而对CD14的蛋白表达无明显影响(P=0.5881）。

  结论 慢性束缚应激模型中小鼠的抑郁样行为可能与星形胶质细胞的表型改变相关，且主要是A1型标记物在星形胶质细胞的高表达。

Objective  To explore the effect of chronic restraint stress(CRS) on the phenotypic transition of hippocampal astrocytes and depression-like behavior in mice.   Methods  Forty eight male C57BL/6 mice were randomly divided into control groups (control), model groups (CRS) and fluoxetine(FLX) drug intervention groups (CRS+FLX), 16 for each group. The mice of the CRS group were subjected to 3 weeks chronic restraint stress. The mice of CRS+FLX group were treated with fluoxetine by intraperitoneal injection 30 minutes before restraint stress from the day 8 to day 21. The mice in the control group and CRS group were treated with the same amount of normal saline (NS). Depression-like behavior was determined by sucrose preference test and open filed test. The expression of astrocytes marker glial fibrillary acidic protein(GFAP) was detected by immunohistochemistry and Western blotting. The expression of A1 and A2 astrocytes markers were detected by Real-time PCR.   Results  Compared with the control group, mice in the CRS group showed obvious depression-like behavior, including a significantly decrease in the percent of sucrose preference (P＜0.0001), a redcued significantly body weight (P＜0.05), and reduced significantly distance travelling in the central area (P＜0.005) in the open field test, which could be reversed by the FLX intervention (P＜0.05). Compared with the control group, the expression of hippocampal astrocytes marker GFAP in the CRS group increased significantly (P＜0.05), which could be reversed by the FLX intervention (P＜0.05). Compared with the control group, the mRNA expression level of the A1 astrocytes markers ［(H2D1, guanylate binding protein 2(GBP2), Fkbp5, Amigo2)］ in the hippocampus of the CRS group were significanlty up-regulated (P＜0.05), which could be reversed by the FLX intervention (P＜0.05). No difference was found in the A2 astrocytes markers mRNA level among the three groups (P＞0.05), except Sphk1 and PTX3. Compared with the control group  , the protein level of hippocampal A1 markers (C3, Fkbp5, GBP2) in CRS group was significanlty up-regulated (P＜0.05), while no difference in the protein level of hippocampal A2 marker CD14 between the two groups (P=0.8361), FLX intervention could significantly reduce the protein level of A1 markers (P＜0.05), but had no obvious effect on the protein expression of CD14 (P=0.5881).   Conclusion The depression-like behavior of mice in the chronic restraint stress model may be related to the phenotypic changes of astrocytes, and it is mainly due to the high expression of type A1 markers in astrocytes.