Department of Obstetrics, Gynecology and Reproductive Sciences, Yale University, New Haven, Connecticut.
Department of Obstetrics & Gynecology, David Geffen School of Medicine at UCLA, Los Angeles, California.
Am J Reprod Immunol. 2018 Nov;80(5):e13044. doi: 10.1111/aji.13044. Epub 2018 Sep 2.
Hyperglycemia increases the risk of preeclampsia. Hyperglycemia induces a placental trophoblast inflammatory (IL-1β, IL-6, IL-8), antiangiogenic (sFlt-1, sEndoglin), and anti-migratory profile. The IL-1β response is mediated via inflammasome activation by the damage-associated molecular pattern (DAMP), uric acid. The objective of this study was to determine the role of high-mobility group box-1 (HMGB1), a DAMP that activates Toll-like receptor 4 (TLR4), in human first trimester trophoblast responses to hyperglycemia. The trophoblast response to excess glucose under different oxygen tensions was also investigated.
The human first trimester trophoblast cell line (Sw.71) was exposed to glucose mimicking normoglycemia (5 mmol/L) and hyperglycemia (10 mmol/L), either alone or with the TLR4 antagonist, LPS-RS; or the HMGB1 inhibitor, glycyrrhizin. Cells were also treated with glucose under hyperoxic (21% O ), normoxic (8% O ), and hypoxic (2% O ) conditions. Cell-free supernatants were assayed by ELISA and bioassays for inflammatory: IL-1β, IL-6, and IL-8; inflammasome-associated: uric acid and caspase-1; angiogenic: sEndoglin, sFlt-1, and PlGF; and the DAMP, HMGB1. Cell migration was measured using a two-chamber colormetric assay.
Excess glucose triggered a trophoblast sterile inflammatory IL-8 and antimigratory response through HMGB1 activation of TLR4. The IL-1β and sFlt-1/PlGF response was TLR4-mediated, but HMGB1-independent, suggesting another DAMP may be involved. Hyperoxia rather than normoxia or hypoxia was a major driver of trophoblast dysfunction in response to excess glucose.
The findings from this study indicate a novel mechanism by which hyperglycemia may impact trophoblast function, early placentation, and ultimately, pregnancy outcome.
高血糖会增加子痫前期的风险。高血糖会诱导胎盘滋养层炎症（IL-1β、IL-6、IL-8）、抗血管生成（sFlt-1、sEndoglin）和抗迁移表型。IL-1β反应是通过损伤相关分子模式（DAMP）尿酸激活炎症小体介导的。本研究的目的是确定高迁移率族蛋白 B1（HMGB1）在人早孕滋养层对高血糖反应中的作用，HMGB1 是一种激活 Toll 样受体 4（TLR4）的 DAMP。还研究了不同氧张力下滋养层对过量葡萄糖的反应。
将人早孕滋养层细胞系（Sw.71）暴露于模拟正常血糖（5mmol/L）和高血糖（10mmol/L）的葡萄糖中，单独或与 TLR4 拮抗剂 LPS-RS 或 HMGB1 抑制剂甘草甜素一起处理。还在高氧（21%O ）、常氧（8%O ）和低氧（2%O ）条件下用葡萄糖处理细胞。通过 ELISA 和生物测定法检测细胞培养液中的炎症因子：IL-1β、IL-6 和 IL-8；炎症小体相关因子：尿酸和半胱氨酸天冬氨酸蛋白酶-1；血管生成因子：sEndoglin、sFlt-1 和 PlGF；DAMP，HMGB1。使用双室比色法测定细胞迁移。
过量葡萄糖通过 HMGB1 激活 TLR4 触发滋养层无菌性炎症 IL-8 和抗迁移反应。IL-1β和 sFlt-1/PlGF 反应是 TLR4 介导的，但 HMGB1 不依赖，表明可能涉及另一种 DAMP。与常氧或低氧相比，高氧是滋养层对过量葡萄糖反应失调的主要驱动因素。
本研究结果表明，高血糖可能通过一种新的机制影响滋养层功能、早期胎盘形成，并最终影响妊娠结局。
