12/15-lipoxygenase: Immune cell mediator linking innate immunity to hypertension

先天免疫和巨噬细胞(MFS)参与高血压的发生和病理生理过程。 MFS中导致高血压的细胞和分子机制存在知识空白。我们 确定了在3种高血压模型中起关键作用的单个基因，Alox15。Alox15编码12/15-脂氧合酶 (12/15-LO)将花生四烯酸代谢成羟基二十碳四烯酸(HETE)。一个重要的角色 通过区分排除12/15-LO的MF和非MF来源的12/15-LO来确定高血压中的MF 12/15-LO： (1)去除野生型(WT)小鼠的MFS(因而MF12/15-LO)可预防高血压。(2)全局删除 Alox15基因(Alox15-/-)可以预防高血压。(3)将含有12/15-LO的WT MF转移到这些 ALOX15-/-小鼠可以恢复高血压。(4)骨髓细胞特异性Alox15缺失可预防高血压。另外， MFS聚集在动脉中，并极化为M1(促炎)表型，但不是M2(抗炎)表型 表型，在WT小鼠中有高血压，但在Alox15-/-小鼠中没有。因此，12/15-LO调节MF M1极化 在高血压方面。这些结果提示有必要了解MF12/15-LO在高血压中的作用。 这项建议的目的是确定12/15-LO及其代谢物作为一种共同途径的作用 高血压通过调节先天免疫的促炎和抗炎途径。中央高铁- MF12/15-LO及其HETE代谢物调节MF12/15-LO的积累、表型和细胞因子的释放 激活血管系统和肾脏中的促高血压机制，导致高血压。(1)我们会 利用Mf靶向缺失Alox15来确定MF12/15-Lo在调节免疫、血管 和肾脏促进高血压的机制。工作假说是MF12/15-LO刺激Mf蓄积。 动脉、肾脏和脑的收缩、极化和细胞因子释放通过激活-β-内酰胺酶参与高血压的发生 增强收缩、抑制扩张、促进肾损伤和减少肾损伤的血管和肾脏机制 钠排泄。(2)HETES对高血压机制的体内作用尚不清楚。封锁 给予外源性HETE以恢复高血压，将绕过ALOX15-/-小鼠的HETE合成。 工作假说是12-和15-HETE刺激免疫、血管和肾脏机制，使 ALOX15-/-小鼠的高血压。(3)中频极化的重要性及12/15-LO对其的调节作用。 张力将被定义。为了确定Alox15缺失是否通过重定向MF极化来预防高血压，在 将使用体内和体外方法将M0 MFS极化为M1或M2表型，以及3种表型 评价膳食纤维耗竭小鼠的高血压恢复情况。工作假设是12/15-LO指导 MF极化到M1表型，而M1，而不是M2，MFS促进高血压。预期的结果将是 通过识别涉及12/15-LO-HETE途径的新的分子机制来推动这一领域的发展 通过指定M1-MF表型来调节MFS和先天性免疫在高血压中的参与 通过调节MFS的血管和肾脏促高血压活性，促进高血压的发生。

Innate immunity and macrophages (MFs) contribute to the development and pathophysiology of hypertension. Knowledge gaps exist for the cellular and molecular mechanisms in MFs that contribute to hypertension. We identified a single gene, Alox15, that is crucial in 3 models of hypertension. Alox15 encodes 12/15-lipoxygenase (12/15-LO) that metabolizes arachidonic acid to hydroxyeicosatetraenoic acids (HETEs). An important role for MF 12/15-LO in hypertension was identified by differentially excluding MF and non-MF sources of 12/15-LO by: (1) Depletion of MFs (and thus MF 12/15-LO) in wild type (WT) mice prevents hypertension. (2) Global deletion of the Alox15 gene (Alox15-/-) prevents hypertension. (3) Transfer of 12/15-LO-containing WT MFs to these Alox15-/- mice restores hypertension. (4) Bone marrow cell-specific Alox15 deletion prevents hypertension. Also, MFs accumulate in arteries and polarize to the M1 (pro-inflammatory) phenotype, but not M2 (anti-inflammatory) phenotype, with hypertension in WT mice but not in Alox15-/- mice. Thus, 12/15-LO regulates MF M1 polarization in hypertension. These results indicate the need to understand the contributions of MF 12/15-LO to hypertension. The objective of this proposal is to define the role of 12/15-LO and its metabolites as a common pathway to hypertension through regulation of the pro- and anti-inflammatory pathways of innate immunity. The central hy- pothesis is MF 12/15-LO and its HETE metabolites regulate MF accumulation, phenotype and cytokine release that activate pro-hypertensive mechanisms in the vasculature and kidneys resulting in hypertension. (1) We will use MF-targeted deletion of Alox15 to establish the crucial role of MF 12/15-LO in regulating immune, vascular and renal pro-hypertensive mechanisms. The working hypothesis is that MF 12/15-LO stimulates MF accumu- lation, polarization and cytokine release in arteries, kidneys and brain that contribute to hypertension by activat- ing vascular and renal mechanisms to enhance constriction, inhibit dilation, promote renal injury and decrease sodium excretion.!(2) The in vivo effects of HETEs on hypertensive mechanisms are unknown. Blockade of HETE synthesis in Alox15-/- mice will be bypassed by administering exogenous HETEs to restore hypertension. The working hypothesis is that 12- and 15-HETE stimulate immune, vascular and renal mechanisms that restore hypertension in Alox15-/- mice. (3) The importance of MF polarization and its regulation by 12/15-LO in hyper- tension will be defined. To determine if Alox15 deletion prevents hypertension by redirecting MF polarization, in vivo and in vitro methods will be used to polarize M0 MFs to the M1 or M2 phenotype, and the 3 phenotypes evaluated for restoration of hypertension in MF-depleted mice. The working hypothesis is that 12/15-LO directs MF polarization to M1 phenotype, and M1, but not M2, MFs promote hypertension. The expected outcomes will advance the field by identifying a new molecular mechanism involving the 12/15-LO-HETE pathway that broadly regulates the participation of MFs and innate immunity in hypertension by specifying the M1 MF phenotype that contributes to hypertension and by mediating vascular and renal pro-hypertensive activities of MFs.