From the Department of Obstetrics and Gynecology (K.B., C.S.B.), The Ohio State University College of Medicine, Columbus.
Department of Pediatrics (C.S.B., I.A.B.), The Ohio State University College of Medicine, Columbus.
Hypertension. 2019 Jun;73(6):1308-1318. doi: 10.1161/HYPERTENSIONAHA.118.12437.
Excessive accumulation of misfolded proteins was recently demonstrated in preeclampsia. We examined levels and activity of circulatory proteasome and immunoproteasome (inflammatory subtype) in preeclampsia and hemolysis, elevated liver enzymes, and thrombocytopenia (HELLP) syndrome. We analyzed samples from women with hypertensive pregnancy disorders (n=115), including preeclampsia with severe features (sPE) and HELLP syndrome, and normotensive controls (n=45). Plasma proteasome and immunoproteasome immunoreactivity were determined by quantifying the α-subunit of the 20S core and β5i (proteasome subunit beta 8 [PSMB8]), respectively. Plasma proteasome activity was analyzed with fluorogenic substrates. MG132, lactacystin, and ONX0914 were used to inhibit the circulating proteasome and immunoproteasome, respectively. Plasma cytokine profiles were evaluated by multiplex immunoassay. Placental expression of β5 (constitutive proteasome) and β5i (immunoproteasome) was interrogated by immunohistochemistry. Women with sPE had increased plasma 20S levels ( P<0.001) and elevated lytic activities (chymotrypsin-like 7-fold, caspase-like 4.2-fold, trypsin-like 2.2-fold; P <0.001 for all) compared with pregnant controls. Women with features of HELLP displayed the highest plasma proteasome levels and activity, which correlated with decreased IFN-γ (interferon-γ), and increased IL (interleukin)-8 and IL-10. In sPE and HELLP, chymotrypsin-like activity was suppressed by proteasome inhibitors including ONX0914. Compared with gestational age-matched controls, sPE placentas harbored increased β5 and β5i immunostaining in trophoblasts. β5i signal was elevated in HELLP with predominant staining in villous core, extravillous trophoblasts in placental islands, and extracellular vesicles in intervillous spaces. Pregnancy represents a state of increased proteostatic stress. sPE and HELLP were characterized by significant upregulation in circulating levels and lytic activity of the proteasome that was partially explained by placental immunoproteasome upregulation.
最近在子痫前期中证实了错误折叠蛋白的过度积累。我们检查了子痫前期和溶血性肝酶升高和血小板减少症（HELLP）综合征中循环蛋白酶体和免疫蛋白酶体（炎症亚型）的水平和活性。我们分析了来自患有高血压妊娠疾病的女性的样本（n=115），包括有严重特征的子痫前期（sPE）和 HELLP 综合征以及血压正常的对照组（n=45）。通过定量 20S 核心的α亚单位和β5i（蛋白酶体亚单位β 8[PSMB8]）分别测定血浆蛋白酶体和免疫蛋白酶体的免疫反应性。用荧光底物分析血浆蛋白酶体活性。MG132、乳胞菌素和 ONX0914 分别用于抑制循环蛋白酶体和免疫蛋白酶体。通过多重免疫测定评估血浆细胞因子谱。通过免疫组织化学检测胎盘β5（组成型蛋白酶体）和β5i（免疫蛋白酶体）的表达。与妊娠对照组相比，sPE 患者的血浆 20S 水平升高（P<0.001），且裂解活性升高（糜蛋白酶样增加 7 倍，半胱天冬酶样增加 4.2 倍，胰蛋白酶样增加 2.2 倍；所有 P<0.001）。具有 HELLP 特征的患者表现出最高的血浆蛋白酶体水平和活性，这与 IFN-γ（干扰素-γ）减少和 IL（白细胞介素）-8 和 IL-10 增加相关。在 sPE 和 HELLP 中，包括 ONX0914 在内的蛋白酶体抑制剂抑制了糜蛋白酶样活性。与胎龄匹配的对照组相比，sPE 胎盘中的滋养层细胞中存在增加的β5 和β5i 免疫染色。在 HELLP 中，β5i 信号升高，主要在绒毛核心、胎盘岛中的绒毛外滋养层和绒毛间腔中的细胞外小泡中染色。妊娠代表一种增加的蛋白质稳态应激状态。sPE 和 HELLP 的特征是循环蛋白酶体水平和裂解活性显著上调，部分原因是胎盘免疫蛋白酶体上调。
