Department of Physiology and Pathophysiology, National Key Discipline of Cell Biology, Fourth Military Medical University, Xi'an, Shaanxi Province, 710032, China.
Department of Occupational & Environmental Health and the Ministry of Education Key Lab of Hazard Assessment and Control in Special Operational Environment, School of Public Health, Fourth Military Medical University, Xi'an, Shaanxi Province, 710032, China.
Biomed Pharmacother. 2020 May;125:109931. doi: 10.1016/j.biopha.2020.109931. Epub 2020 Feb 14.
κ-opioid receptor (κ-OR) plays a key role in preventing hypoxic pulmonary hypertension (HPH) development after activated by exogenous agonist U50,488H. Calcium sensing receptor (CaSR) activation induces HPH by promoting vasoconstriction and vascular remodeling. The activated κ-OR is reported to inhibit the expression of CaSR in pulmonary artery smooth muscle cells (PASMCs). Thus, in this study, we aimed to explore the effect of activated κ-OR on the role of CaSR in preventing HPH development. An HPH rat model was constructed using Sprague-Dawley rats. Changes in mean pulmonary arterial pressure (mPAP) and right ventricular pressure (RVP) mediated by κ-OR agonist U50,488H and CaSR inhibitor NPS2143 were observed. The effects of CaSR agonist spermine and inhibitor NPS2143 on pulmonary artery tension were tested. The expression and localization of κ-OR and CaSR were measured in isolated PASMCs. A cell-counting kit-8 assay was performed to evaluate the effect of spermine in PASMC proliferation. Expression of proliferating cell nuclear antigen (PCNA), Erk, and p-Erk was evaluated by western blot analysis. Results showed that κ-OR and CaSR were co-expressed and colocalized in PASMCs under normoxic and hypoxic conditions. Interactions between κ-OR and CaSR were also observed. Spermine improved vasoconstriction in the pulmonary artery in HPH rats, which was abolished by U50,488H. RVP and mPAP were significantly increased in HPH rats under CaSR stimulation, but were significantly reduced when the rats were pretreated with U50,488H and NPS2143 (P < 0.01). Spermine treatment significantly promoted PASMC proliferation, which was significantly inhibited by U50,488H, p38 inhibitor SB203580, JNK inhibitor SP600125, Erk inhibitor SCH772984, and MEK inhibitor U0126, especially Erk inhibitor (P < 0.01). Spermine significantly increased PCNA and P-Erk expression in hypoxic conditions, which was inhibited by U50,488H and NPS2143. κ-OR stimulation prevented HPH development via the CaSR/MAPK signaling pathway.
κ-阿片受体（κ-OR）在预防外源性激动剂 U50,488H 激活后缺氧性肺动脉高压（HPH）的发展中起着关键作用。钙敏感受体（CaSR）的激活通过促进血管收缩和血管重塑来诱导 HPH。据报道，激活的 κ-OR 可抑制肺动脉平滑肌细胞（PASMC）中 CaSR 的表达。因此，在这项研究中，我们旨在探讨激活的 κ-OR 对 CaSR 在预防 HPH 发展中的作用的影响。使用 Sprague-Dawley 大鼠构建 HPH 大鼠模型。观察κ-OR 激动剂 U50,488H 和 CaSR 抑制剂 NPS2143 介导的平均肺动脉压（mPAP）和右心室压（RVP）的变化。测试 CaSR 激动剂 spermine 和抑制剂 NPS2143 对肺动脉张力的影响。测量分离的 PASMC 中 κ-OR 和 CaSR 的表达和定位。通过细胞计数试剂盒-8 测定法评估 spermine 对 PASMC 增殖的影响。通过 Western blot 分析评估增殖细胞核抗原（PCNA）、Erk 和 p-Erk 的表达。结果表明，在常氧和缺氧条件下，κ-OR 和 CaSR 在 PASMC 中共同表达和共定位。还观察到 κ-OR 和 CaSR 之间的相互作用。spermine 改善了 HPH 大鼠肺动脉的血管收缩，该作用被 U50,488H 消除。在 CaSR 刺激下，HPH 大鼠的 RVP 和 mPAP 显着增加，但在用 U50,488H 和 NPS2143 预处理后显着降低（P <0.01）。spermine 处理显着促进 PASMC 增殖，而 U50,488H、p38 抑制剂 SB203580、JNK 抑制剂 SP600125、Erk 抑制剂 SCH772984 和 MEK 抑制剂 U0126 特别是 Erk 抑制剂（P <0.01）可显著抑制该作用。spermine 在缺氧条件下显着增加 PCNA 和 P-Erk 的表达，而 U50,488H 和 NPS2143 可抑制其表达。κ-OR 刺激通过 CaSR/MAPK 信号通路预防 HPH 发展。
