目的 探讨丝裂原激活蛋白激酶激酶激酶激酶 4（Map4k4）在血管紧张素Ⅱ（AngⅡ）诱导的动脉粥样硬化（AS）易损斑块形成中的调节作用。方法 ApoE-/-小鼠随机分为 4 组（每组 8 只）： Control组、AngⅡ组、AngⅡ+shMap4k4组和AngⅡ+Map4k4组。采用油红O染色（脂质）、Masson染色（胶原）、 α⁃肌动蛋白免疫荧光染色（平滑肌细胞）和 F4/80 染色（巨噬细胞）检测主动脉窦斑块稳定性。通过免疫荧 光和 Western blot 分析 Map4k4 表达。体外构建 Map4k4 敲低或过表达巨噬细胞，用于确认 Map4k4 在 AngⅡ 诱导的细胞凋亡中的作用。结果 Ang Ⅱ促进了ApoE⁃/⁃小鼠AS斑块易损性和巨噬细胞凋亡（P < 0.05），伴 随着 Map4k4 表达的上调（P < 0.05）。与 Ang Ⅱ组小鼠相比，Ang Ⅱ+shMap4k4 组小鼠的 AS 斑块易损性 ［（1.22 ± 0.06）vs.（0.49 ± 0.04）］和巨噬细胞凋亡［（8.42 ± 0.40）vs.（3.49 ± 0.31）］明显减弱（P < 0.05），而 AngⅡ+Map4k4 组小鼠上述指标明显增强［（1.22 ± 0.06）vs.（1.45 ± 0.05），（8.42 ± 0.40）vs.（14.11 ± 0.78）， P < 0.05］。体外实验显示，Map4k4敲低有效减弱了Ang Ⅱ诱导的c⁃Caspase3、Bax蛋白表达增加（P < 0.05）， 并增加了 Bcl⁃2 蛋白表达（P < 0.05）。而 Map4k4 过表达进一步增强了 Ang Ⅱ的诱导作用（P < 0.05）。结论 Ang Ⅱ通过上调Map4k4表达促进巨噬细胞凋亡，并进一步参与AS中易损斑块的形成。

Objective To explore the regulatory role of mitogen ⁃activated protein kinase kinase kinase kinase 4（Map4k4）in the formation of vulnerable plaques in atherosclerosis（AS）induced by angiotensin Ⅱ（AngⅡ）. Methods Thirty⁃two ApoE-/- mice were randomly divided into four groups（8 in each group）：control，AngⅡ， AngⅡ+shMap4k4 and AngⅡ+Map4k4. Oil red O staining（lipid），Masson staining（collagen），α⁃actin immuno⁃ fluorescence staining（smooth muscle cells）and F4/80 staining（macrophages）were used to detect the stability of aortic sinus plaque. The expression of Map4k4 was analyzed by immunofluorescence and Western blot. Map4k4 knockdown or overexpression macrophages were constructed in vitro to confirm the role of Map4k4 in AngⅡ⁃in⁃ duced apoptosis. Results The atherosclerotic plaque vulnerability and macrophage apoptosis were promoted in ApoE-/- mice by Ang Ⅱ（P < 0.05），accompanied by the upregulation of Map4k4 expression. Compared with the AngⅡ group（P < 0.05），the AS plaque vulnerability［（1.22 ± 0.06）vs.（0.49 ± 0.04）］and macrophage apoptosis ［（8.42 ± 0.40）vs.（3.49 ± 0.31）］of the Ang Ⅱ+shMap4k4 group were significantly reduced（P < 0.05），while the above indicators of the Ang Ⅱ+Map4k4 group were significantly enhanced［（1.22 ± 0.06）vs.（1.45 ± 0.05）； （8.42 ± 0.40）vs（. 14.11 ± 0.78），P < 0.05］. In vitro experiments showed that Map4k4 knockdown effectively atten⁃ uated the increased expression of c⁃Caspase3 and Bax protein induced by AngⅡ（P < 0.05），and enhanced the expression of Bcl ⁃2 protein（P < 0.05）. The overexpression of Map4k4 further enhanced the induction of Ang Ⅱ （P < 0.05）. Conclusion Ang Ⅱ via upregulating Map4k4 expression promotes macrophage apoptosis so as to promote vulnerable plaque formation in AS.