Dutta Shubha R, Singh Purnima, Song Chi Young, Shin Ji Soo, Malik Kafait U
Department of Pharmacology, Addiction Science, and Toxicology, College of Medicine, University of Tennessee Health Science Center, Memphis, TN.
Hypertension. 2025 Apr;82(4):e34-e46. doi: 10.1161/HYPERTENSIONAHA.124.23905. Epub 2025 Feb 4.
Our previous findings that arachidonic acid-12/15-lipoxygenase (LOX)-generated metabolite 12(S)-HETE contributes to angiotensin II (AngII)-induced hypertension and 17β-estradiol protects from AngII-induced hypertension via its cytochrome P450 (CYP)1B1-generated metabolite 2-methoxyestradiol in the paraventricular nucleus (PVN) in female mice led us to test the hypothesis that 2-methoxyestradiol acts by inhibiting the LOX/12(S)-HETE in the PVN.
AngII was infused subcutaneously by osmotic pumps for 2 weeks in wild-type, LOX-knockout (LOXKO), and CYP1B1KO female mice. The blood pressure was measured by tail-cuff/radiotelemetry. Adenovirus (Ad)-GFP (green fluorescence protein)-LOX-short hairpin RNA, Ad-GFP-LOX-DNA, 12(S)-HETE, and 2-methoxyestradiol were injected selectively in PVN or intracerebroventricularly. Histological, immunohistochemical, and biochemical techniques were used to determine pathophysiological changes caused by various interventions.
AngII-induced hypertension that was exaggerated in CYP1B1KO compared with wild-type mice was minimized by PVN-LOX knockdown with Ad-LOX-short hairpin RNA and restored by PVN-LOX reconstitution with Ad-LOX-DNA in intact-LOXKO mice and exacerbated in ovariectomized-LOXKO mice. Furthermore, intracerebroventricular-12(S)-HETE restored AngII-induced increases in blood pressure, autonomic impairment, neuroinflammation, and renal pathogenesis in intact-LOXKO mice, which were exacerbated in ovariectomized-LOXKO mice. Intracerebroventricular-2-methoxyestradiol that reduced the LOX expression and 12(S)-HETE content in PVN minimized AngII effects mentioned above in ovariectomized-LOXKO mice transduced with intracerebroventricular-Ad-LOX-DNA.
These data suggest that 2-methoxyestradiol protects against AngII-induced hypertension and associated pathogenesis, most likely by inhibiting LOX/12(S)-HETE actions in the PVN of female mice. Therefore, the selective LOX inhibitors or 12(S)-HETE receptor antagonists could be useful in treating hypertension and its pathogenesis in postmenopausal, hypoestrogenic women or females with ovarian failure.
我们之前的研究发现，花生四烯酸 - 12/15 - 脂氧合酶（LOX）生成的代谢产物12(S)-HETE会导致血管紧张素II（AngII）诱导的高血压，而17β-雌二醇通过其在雌性小鼠室旁核（PVN）中由细胞色素P450（CYP）1B1生成的代谢产物2 - 甲氧基雌二醇来预防AngII诱导的高血压。这使我们去验证一个假说，即2 - 甲氧基雌二醇通过抑制PVN中的LOX/12(S)-HETE发挥作用。
通过渗透泵给野生型、LOX基因敲除（LOXKO）和CYP1B1基因敲除（CYP1B1KO）的雌性小鼠皮下输注AngII，持续2周。用尾套法/无线电遥测技术测量血压。将腺病毒（Ad）-绿色荧光蛋白（GFP）-LOX短发夹RNA、Ad - GFP - LOX - DNA、12(S)-HETE和2 - 甲氧基雌二醇选择性地注射到PVN或脑室内。采用组织学、免疫组织化学和生化技术来确定各种干预措施引起的病理生理变化。
与野生型小鼠相比，CYP1B1KO小鼠中AngII诱导的高血压更为严重，在完整的LOXKO小鼠中，通过Ad - LOX短发夹RNA敲低PVN中的LOX可使这种高血压最小化，而通过Ad - LOX - DNA在PVN中重新构建LOX可使其恢复，在去卵巢的LOXKO小鼠中则会加剧。此外，脑室内注射12(S)-HETE可恢复完整的LOXKO小鼠中AngII诱导的血压升高、自主神经功能障碍、神经炎症和肾脏病变，而去卵巢的LOXKO小鼠中这些情况会加剧。脑室内注射2 - 甲氧基雌二醇可降低PVN中的LOX表达和12(S)-HETE含量，从而使上述AngII的影响在经脑室内Ad - LOX - DNA转导的去卵巢的LOXKO小鼠中最小化。
这些数据表明，2 - 甲氧基雌二醇可预防AngII诱导的高血压及相关病变，很可能是通过抑制雌性小鼠PVN中的LOX/12(S)-HETE的作用。因此，选择性LOX抑制剂或12(S)-HETE受体拮抗剂可能对治疗绝经后、雌激素缺乏的女性或卵巢功能衰竭女性的高血压及其病变有用。
