2-Methoxyestradiol protects from angiotensin II-induced renal CD3+/FOXP3+ T cell-dysregulation via 12/15 lipoxygenase inhibition
Authors: Singh Purnima , Dutta Shubha Ranjan , Malik Kafait U. 
Published: May 2024

We previously showed that 2-methoxyestradiol (2-ME), an active metabolite of 17β-estradiol (E2) and lox (12/15-lipoxygenase) gene disruption, protects against angiotensin (Ang) II-induced hypertension. Moreover, 2-ME reduces Ang II-induced increases in plasma levels of 12(S)-hydroxyeicosatetraenoic acid (HETE), a major arachidonic acid-LOX-generated metabolite in ovariectomized (OVX, endogenous E2 depleted) wild-type (WT) mice. 2-ME also exerts anti-inflammatory effects, and regulatory T cells (Tregs) have been reported to impact Ang II-induced hypertension in rodent models, with premenopausal females being protected relative to males. This study tested the hypothesis that 2-ME protects against the inflammatory effects of Ang II by upregulating Tregs in the kidney via LOX inhibition in female mice. Intact (ovaries present) or OVX WT and OVX-LOX knock-out (KO) mice (8-10 weeks, n=3-4/group) were infused with Ang II (700 ng/kg/min) or saline (vehicle) via osmotic minipumps (S.C.) with or without 2-ME (15 μg/g, I.P., every third day) treatment for 2 weeks. Renal protein expressions of CD3+ T cells and FOXP3+ Tregs were evaluated by immunofluorescence staining and mRNA expressions of tnf-α and il-10 by RT-PCR using TaqMan assay (relative to saline-infused intact WT) in the whole kidney. Results represented as mean ± SEM were analyzed using one-way ANOVA followed by Tukey's multiple comparisons test. The CD3+, tnf-α and il-10 expressions were comparable between saline-infused intact WT, OVX-WT, and OVX-KO (CD3+: 8.3±0.3, 7.0±0.5, 6.3±0.3; tnf-α: 1.0±0.0, 0.9±0.0, 0.8±0.2; il-10: 1.1±0.1, 0.9±0.1, 1.0±0.0). However, saline-infused intact WT and OVX-KO expressed higher Tregs (p<0.05) as compared to OVX-WT (7.6±0.3, 7.3±0.3 vs 4.0±0.5). Ang II increased CD3+, Tregs, and il-10 (p<0.05) but not tnf-α expressions as compared to its vehicle in intact WT (12.6±0.3, 15.3±0.3, 3.7±0.3,0.8±0.1). Ang II also increased CD3+ (11.0±0.6) and Tregs (11.0±0.6) in OVX-KO (p<0.05), without altering mRNA expressions of tnf-α (0.9±0.3) and il-10 (1.5±0.1) . In contrast, Ang II resulted in a greater increase in CD3+ (25.0±1.1) in OVX-WT than OVX-KO and intact WT, besides increasing tnf-α expression (2.5±0.4) (p<0.05). 2-ME reduced CD3+ (16.7±0.9) and tnf-α (1.4±0.4) expressions, and increased Tregs (10.0±1.0) and il-10 (2.0±0.0) expressions in Ang II-infused OVX-WT mice (p<0.05). 2-ME also reduced CD3+ (6.7±0.3, p<0.05) and showed a trend to increase Tregs (14.0±1.1, P=0.056), and il-10 (2.3±0.2, P=0.058) expressions without altering tnf-α (0.7±0.1) expression in Ang II-infused OVX-KO mice. In conclusion, Ang II produces a specific effect on the renal T cell profile, greater increases in proinflammatory T cells in OVX mice, and anti-inflammatory Tregs in intact female mice, most likely mediated by E2 through metabolite 2-ME via inhibition of LOX. R01HL19134-47, AHA Award#940538. This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.