Singh Purnima, Song Chi Young, Dutta Shubha Ranjan, Gonzalez Frank J, Malik Kafait U
From the Department of Pharmacology, Addiction Science, and Toxicology, College of Medicine, University of Tennessee Health Science Center, Memphis (P.S., C.Y.S., S.R.D., K.U.M.).
Laboratory of Metabolism, National Cancer Institute, Bethesda, MD (F.J.G.).
Hypertension. 2020 Apr;75(4):1054-1062. doi: 10.1161/HYPERTENSIONAHA.119.14548. Epub 2020 Mar 9.
Previously, we showed that peripheral administration of 2-ME (2-methoxyestradiol), a CYP1B1 (cytochrome P450 1B1)-catechol--methyltransferase (COMT) generated metabolite of E2 (17β-Estradiol), protects against angiotensin II-induced hypertension in female mice. The demonstration that central E2 inhibits angiotensin II-induced hypertension, together with the expression of CYP1B1 in the brain, led us to hypothesize that E2-CYP1B1 generated metabolite 2-ME in the brain mediates its protective action against angiotensin II-induced hypertension in female mice. To test this hypothesis, we examined the effect of intracerebroventricularly (ICV) administered E2 in ovariectomized (OVX)-wild-type () and OVX- mice on the action of systemic angiotensin II. ICV-E2 attenuated the angiotensin II-induced increase in mean arterial blood pressure, impairment of baroreflex sensitivity, and sympathetic activity in OVX- but not in ICV-injected short interfering (si)RNA-COMT or OVX- mice. ICV-2-ME attenuated the angiotensin II-induced increase in blood pressure in OVX- mice; this effect was inhibited by ICV-siRNA estrogen receptor-α (ERα) and G protein-coupled estrogen receptor 1 (GPER1). ICV-E2 in OVX- but not in OVX- mice and 2-ME in the OVX- inhibited angiotensin II-induced increase in reactive oxygen species production in the subfornical organ and paraventricular nucleus, activation of microglia and astrocyte, and neuroinflammation in paraventricular nucleus. Furthermore, central CYP1B1 gene disruption in mice by ICV-adenovirus-GFP (green fluorescence protein)-CYP1B1-short hairpin (sh)RNA elevated, while reconstitution by adenovirus-GFP-CYP1B1-DNA in the paraventricular nucleus but not in subfornical organ in mice attenuated the angiotensin II-induced increase in systolic blood pressure. These data suggest that E2-CYP1B1-COMT generated metabolite 2-ME, most likely in the paraventricular nucleus via estrogen receptor-α and GPER1, protects against angiotensin II-induced hypertension and neuroinflammation in female mice.
此前，我们发现，外周给予2-ME（2-甲氧基雌二醇）（一种由CYP1B1（细胞色素P450 1B1）-儿茶酚-O-甲基转移酶（COMT）生成的E2（17β-雌二醇）代谢产物）可保护雌性小鼠免受血管紧张素II诱导的高血压影响。中枢E2可抑制血管紧张素II诱导的高血压，且CYP1B1在脑中表达，这使我们推测，E2-CYP1B1在脑中生成的代谢产物2-ME介导了其对雌性小鼠血管紧张素II诱导的高血压的保护作用。为验证这一假设，我们研究了脑室注射（ICV）E2对去卵巢（OVX）-野生型（WT）和OVX-CYP1B1基因敲除小鼠全身血管紧张素II作用的影响。ICV-E2可减轻血管紧张素II诱导的OVX-WT小鼠平均动脉血压升高、压力感受性反射敏感性受损及交感神经活动增强，但对ICV注射短发夹RNA（sh）-COMT或OVX-CYP1B1基因敲除小鼠无此作用。ICV-2-ME可减轻血管紧张素II诱导的OVX-WT小鼠血压升高；该作用被ICV-siRNA雌激素受体-α（ERα）和G蛋白偶联雌激素受体1（GPER1）抑制。OVX-WT而非OVX-CYP1B1基因敲除小鼠的ICV-E2以及OVX-WT小鼠的2-ME可抑制血管紧张素II诱导的穹窿下器和室旁核活性氧生成增加、小胶质细胞和星形胶质细胞激活以及室旁核神经炎症。此外，通过ICV-腺病毒-绿色荧光蛋白（GFP）-CYP1B1-短发夹RNA破坏小鼠中枢CYP1B1基因可使血管紧张素II诱导的收缩压升高，而通过腺病毒-GFP-CYP1B1-DNA在小鼠室旁核而非穹窿下器进行重建可减轻血管紧张素II诱导的收缩压升高。这些数据表明，E2-CYP1B1-COMT生成的代谢产物2-ME最有可能通过雌激素受体-α和GPER1在室旁核发挥作用，保护雌性小鼠免受血管紧张素II诱导的高血压和神经炎症影响。
