钙敏感受体对持续肺动脉高压新生小鼠Ⅱ型11β-羟基类固醇脱氢酶及皮质醇的影响

Effects of calcium-sensitive receptors on 11β-hydroxysteroid dehydrogenase type 2 and cortisol in neonatal mice with persistent pulmonary hypertension

摘要:

目的 研究钙敏感受体（CaSR）在持续肺动脉高压（PPH）新生小鼠模型中对Ⅱ型11β-羟基类固醇脱氢酶（11β-HSD2）表达及皮质醇浓度的影响。方法 56只新生C57BL/6小鼠随机分为对照组、PPH组、激动剂组及抑制剂组（n=14）。PPH组、激动剂组和抑制剂组小鼠暴露在12%的氧浓度环境中，激动剂组和抑制剂组小鼠每天分别给予CaSR激动剂GdCl3（16 mg/kg）及其抑制剂NPS2390（1 mg/kg）腹腔注射1次；对照组小鼠暴露在空气中，并和PPH组每日以等量生理盐水替代注射；共持续14 d。采用苏木精-伊红染色行心脏和肺组织形态学检测；实时荧光定量PCR和Western bolt法分别检测各组小鼠肺组织中11β-HSD2 mRNA及其蛋白的表达水平；ELISA法检测各组小鼠肺组织中脑利钠肽（BNP）和皮质醇水平。结果 与对照组相比，PPH组肺小动脉血管壁厚度（WT%）、右心室与左心室壁厚度比（RV/LV）、肺泡平均内衬间隔及BNP浓度明显增加，径向肺泡计数减少（P < 0.05）；WT%和BNP浓度在激动剂组较PPH组有所加重，而上述指标在抑制剂组均较PPH组有所减轻（P < 0.05）。与对照组相比，PPH组的11β-HSD2 mRNA及其蛋白表达水平降低，皮质醇浓度增加（P < 0.05）；上述指标在激动剂组均较PPH组进一步加重，而在抑制剂组有一定程度的逆转（P < 0.05）。结论 CaSR可能通过调节11β-HSD2的表达及皮质醇浓度来控制新生小鼠PPH的发生发展。

Abstract:

Objective To investigate the effects of calcium-sensitive receptors (CaSR) on the expression of 11β-hydroxysteroid dehydrogenase type 2 (11β-HSD2) and cortisol concentration in a neonatal mouse model of persistent pulmonary hypertension (PPH). Methods Fifty-six newborn C57BL/6 mice were randomly divided into a control group (n=14), a PPH group (n=14), an agonist group (n=14), and an inhibitor group (n=14). The mice in the PPH, agonist, and inhibitor groups were exposed to a 12% oxygen concentration, and the agonist group and inhibitor group were given CaSR agonist (GdCl3, 16 mg/kg) and CaSR antagonist (NPS2390, 1 mg/kg) intraperitoneally once a day, respectively. The mice in control group were exposed to air, and then injected with an equal volume of normal saline as those in the PPH group every day. All mice were treated for 14 days. Morphological examination of heart and lung tissues was performed using hematoxylin-eosin staining. The expression levels of 11β-HSD2 mRNA and 11β-HSD2 protein in lung tissues were measured by qRT-PCR and Western blot respectively. Brain natriuretic peptide (BNP) and cortisol levels in lung tissues were determined using ELISA. Results Compared with the control group, the PPH group had significantly increased pulmonary artery wall thickness (WT%), ratio of right to left ventricular thickness (RV/LV), alveolar mean linear intercept, and BNP concentration and a significantly reduced radial alveolar count (P < 0.05); compared with the PPH group, the agonist group showed significant increases in WT% and BNP concentration, while the inhibitor group showed significant reductions in the two indicators (P < 0.05). Compared with the control group, the PPH group showed significant reductions in the expression levels of 11β-HSD2 mRNA and 11β-HSD2 protein, but a significant increase in cortisol concentration (P < 0.05); compared with the PPH group, the agonist group had significantly lower expression levels of 11β-HSD2 mRNA and 11β-HSD2 protein, but a significant higher cortisol concentration, while the inhibitor group showed opposite changes in these indicators (P < 0.05). Conclusions CaSR may control the development and progression of PPH in newborn mice by regulating the expression of 11β-HSD2 and cortisol concentration.