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

天然免疫和巨噬细胞（MFs）参与了高血压的发生和病理生理过程。 在微纤维化导致高血压的细胞和分子机制方面存在知识空白。我们 确定了一个单一的基因，Alox 15，这是至关重要的3种高血压模型。Alox 15编码12/15-脂氧合酶 (12/15-LO），其将花生四烯酸代谢为羟基二十碳四烯酸（HETE）。的一个重要作用 通过以下方法区分排除12/15-LO的MF和非MF来源，确定高血压中的MF 12/15-LO： (1)野生型（WT）小鼠中MF（以及因此MF 12/15-L0）的消耗预防高血压。(2)全局删除 Alox 15基因（Alox 15-/-）可以预防高血压。(3)将含12/15-LO的WT MF转移至这些 Alox 15-/-小鼠恢复高血压。(4)骨髓细胞特异性Alox 15缺失可预防高血压还有， MF在动脉中积累并转化为M1（促炎）表型，但不转化为M2（抗炎）表型。 表型，在WT小鼠中具有高血压，但在Alox 15-/-小鼠中没有。因此，12/15-LO调节MF M1偏振 在高血压中。这些结果表明，需要了解MF 12/15-LO对高血压的贡献。 本提案的目的是确定12/15-LO及其代谢产物作为一种常见途径的作用， 通过调节先天性免疫的促炎和抗炎途径来治疗高血压。中央卫生- 假设MF 12/15-LO及其HETE代谢产物调节MF蓄积、表型和细胞因子释放 其激活脉管系统和肾脏中的促高血压机制，导致高血压。(1)我们将 使用MF靶向的Alox 15缺失来确定MF 12/15-LO在调节免疫、血管、 和肾促高血压机制。工作假设是MF 12/15-LO刺激MF神经元， 动脉、肾脏和大脑中的极化、极化和细胞因子释放，通过激活 血管和肾脏机制，以增强收缩，抑制扩张，促进肾损伤和减少 钠排泄！(2)HETE对高血压机制的体内影响尚不清楚。封锁 通过施用外源性HETE以恢复高血压，将绕过Alox 15-/-小鼠中的HETE合成。 工作假设是12-和15-HETE刺激免疫、血管和肾脏机制， Alox 15-/-小鼠的高血压。(3)本文讨论了MF偏振的重要性以及12/15-LO对MF偏振的调节作用。 张力将被定义。为了确定Alox 15缺失是否通过重定向MF极化来预防高血压， 将使用体内和体外方法将M0 MF转化为M1或M2表型，并将3种表型转化为M1或M2表型。 评估MF耗尽小鼠中高血压的恢复。工作假设是12/15-LO指导 MF极化为M1表型，M1，而不是M2，MF促进高血压。预期成果将 通过确定一种涉及12/15-LO-HETE途径的新分子机制， 通过指定M1 MF表型来调节MF和先天免疫在高血压中的参与， 导致高血压，并通过介导MF的血管和肾脏促高血压活性。

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.