Table_1_Cholesterol Crystals and NLRP3 Mediated Inflammation in the Uterine Wall Decidua in Normal and Preeclamptic Pregnancies.docx

Preeclampsia is a hypertensive and inflammatory pregnancy disorder associated with cholesterol accumulation and inflammation at the maternal-fetal interface. Preeclampsia can be complicated with fetal growth restriction (FGR) and shares risk factors and pathophysiological mechanisms with cardiovascular disease. Cholesterol crystal mediated NLRP3 inflammasome activation is central to cardiovascular disease and the pathway has been implicated in placental inflammation in preeclampsia. Direct maternal-fetal interaction occurs both in the uterine wall decidua and at the placental surface and these aligned sites constitute the maternal-fetal interface. This study aimed to investigate cholesterol crystal accumulation and NLRP3 inflammasome expression by maternal and fetal cells in the uterine wall decidua of normal and preeclamptic pregnancies. Pregnant women with normal (n = 43) and preeclamptic pregnancies with (n = 28) and without (n = 19) FGR were included at delivery. Cholesterol crystals were imaged in decidual tissue by both second harmonic generation microscopy and polarization filter reflected light microscopy. Quantitative expression analysis of NLRP3, IL-1β and cell markers was performed by immunohistochemistry and automated image processing. Functional NLRP3 activation was assessed in cultured decidual explants. Cholesterol crystals were identified in decidual tissue, both in the tissue stroma and near uterine vessels. The cholesterol crystals in decidua varied between pregnancies in distribution and cluster size. Decidual expression of the inflammasome components NLRP3 and IL-1β was located to fetal trophoblasts and maternal leukocytes and was strongest in areas of proximity between these cell types. Pathway functionality was confirmed by cholesterol crystal activation of IL-1β in cultured decidual explants. Preeclampsia without FGR was associated with increased trophoblast dependent NLRP3 and IL-1β expression, particularly in the decidual areas of trophoblast and leukocyte proximity. Our findings suggest that decidual accumulation of cholesterol crystals may activate the NLRP3 inflammasome and contribute to decidual inflammation and that this pathway is strengthened in areas with close maternal-fetal interaction in preeclampsia without FGR.

子痫前期（Preeclampsia）是一类以高血压与炎症为特征的妊娠并发症，其发病与母胎界面的胆固醇蓄积及炎症反应紧密相关。子痫前期可并发胎儿生长受限（Fetal Growth Restriction, FGR），且与心血管疾病共享危险因素与病理生理机制。胆固醇晶体介导的NLRP3炎症小体（NLRP3 inflammasome）活化是心血管疾病的核心病理过程，该通路亦被证实参与子痫前期的胎盘炎症反应。母胎直接交互既发生于子宫壁蜕膜（decidua），也存在于胎盘表面，上述区域共同构成母胎界面。本研究旨在探究正常妊娠与子痫前期妊娠患者的子宫壁蜕膜中，母胎细胞的胆固醇晶体蓄积情况及NLRP3炎症小体的表达水平。本研究纳入分娩时的正常妊娠孕妇（n=43）、伴FGR的子痫前期孕妇（n=28）及不伴FGR的子痫前期孕妇（n=19）。研究人员通过二次谐波生成显微镜与偏振滤光反射光显微镜，对蜕膜组织中的胆固醇晶体进行成像。采用免疫组织化学结合自动化图像处理技术，对NLRP3、白细胞介素1β（Interleukin 1β, IL-1β）及细胞标志物的表达进行定量分析。对体外培养的蜕膜外植体开展功能学NLRP3活化检测。研究结果显示：蜕膜组织的基质区域及子宫血管附近均可检测到胆固醇晶体；不同妊娠个体的蜕膜胆固醇晶体在分布模式与簇集大小上存在差异。蜕膜中炎症小体组分NLRP3与IL-1β的表达定位于胎儿滋养层细胞与母体白细胞，且在两类细胞紧密毗邻的区域表达水平最高。通过胆固醇晶体刺激培养的蜕膜外植体分泌IL-1β，证实了该通路的功能性。不伴FGR的子痫前期患者，其滋养层依赖性的NLRP3与IL-1β表达水平显著升高，尤以滋养层与白细胞紧密毗邻的蜕膜区域最为明显。本研究结果提示，蜕膜内胆固醇晶体蓄积可活化NLRP3炎症小体，进而介导蜕膜炎症反应；且在不伴FGR的子痫前期患者中，母胎紧密交互的区域该通路的激活程度显著增强。