Troiano Jéssica A, Potje Simone R, Graton Murilo E, Gonçalves Emily T, Tostes Rita C, Antoniali Cristina
Programa de Pós-graduação Multicêntrico em Ciências Fisiológicas, SBFis, São Paulo State University (UNESP), Araçatuba, Brazil.
Department of Basic Sciences, School of Dentistry, São Paulo State University (UNESP), Araçatuba, Brazil.
Front Physiol. 2021 Nov 9;12:760237. doi: 10.3389/fphys.2021.760237. eCollection 2021.
We have investigated the role caveolae/caveolin-1 (Cav-1) plays in endothelial nitric oxide synthase (eNOS) activation and how it impacts pregnancy-induced decreased vascular reactivity in normotensive (Wistar rats) and spontaneously hypertensive rats (SHR). Wistar rats and SHR were divided into non-pregnant (NP) and pregnant (P). Nitrite levels were assessed by the Griess method in the aorta and mesenteric vascular bed. In functional studies, arteries were incubated with methyl-β-cyclodextrin (dextrin, 10mmol/L), which disrupts caveolae by depleting cholesterol, and concentration-response curves to phenylephrine (PE) and acetylcholine (ACh) were constructed. Electronic microscopy was used to determine endothelial caveolae density in the aorta and resistance mesenteric artery in the presence of vehicle or dextrin (10mmol/L). Western blot was performed to evaluate Cav-1, p-Cav-1, calmodulin (CaM), and heat shock protein 90 (Hsp90) expression. Cav-1/eNOS interaction in the aorta and mesenteric vascular bed was assessed by co-immunoprecipitation. Nitric oxide (NO) generation was greater in arteries from P groups compared to NP groups. Dextrin did not change vascular responses in the aorta from P groups or the number of caveolae in P groups compared to NP groups. Compared to NP Wistar rats, NP SHR showed smaller number of caveolae and reduced Cav-1 expression. Pregnancy did not alter Cav-1, CaM, or Hsp90 expression in the aorta or mesenteric vascular bed from Wistar rats or SHR. These results suggest that pregnancy does not alter expression of the main eNOS regulatory proteins, but it decreases Cav-1/eNOS interaction. Reduced Cav-1/eNOS interaction in the aorta and mesenteric vascular bed seems to be an important mechanism to increase eNOS activity and nitric oxide production in pregnant normotensive and hypertensive rats.
我们研究了小窝/小窝蛋白-1（Cav-1）在内皮型一氧化氮合酶（eNOS）激活中所起的作用，以及它如何影响正常血压（Wistar大鼠）和自发性高血压大鼠（SHR）妊娠诱导的血管反应性降低。将Wistar大鼠和SHR分为非妊娠（NP）组和妊娠（P）组。采用Griess法评估主动脉和肠系膜血管床中的亚硝酸盐水平。在功能研究中，将动脉与甲基-β-环糊精（糊精，10mmol/L）一起孵育，后者通过消耗胆固醇破坏小窝，并构建对去氧肾上腺素（PE）和乙酰胆碱（ACh）的浓度-反应曲线。使用电子显微镜确定在存在载体或糊精（10mmol/L）的情况下主动脉和肠系膜阻力动脉中的内皮小窝密度。进行蛋白质免疫印迹法以评估Cav-1、磷酸化Cav-1、钙调蛋白（CaM）和热休克蛋白90（Hsp90）的表达。通过免疫共沉淀评估主动脉和肠系膜血管床中Cav-1/eNOS的相互作用。与NP组相比，P组动脉中的一氧化氮（NO）生成更多。与NP组相比，糊精并未改变P组主动脉中的血管反应或P组中的小窝数量。与NP Wistar大鼠相比，NP SHR的小窝数量更少且Cav-1表达降低。妊娠并未改变Wistar大鼠或SHR的主动脉或肠系膜血管床中Cav-1、CaM或Hsp90的表达。这些结果表明，妊娠不会改变主要eNOS调节蛋白的表达，但会减少Cav-1/eNOS的相互作用。主动脉和肠系膜血管床中Cav-1/eNOS相互作用的减少似乎是增加正常血压和高血压妊娠大鼠中eNOS活性和一氧化氮生成的重要机制。
