■肺动脉高压(PAH)是肺部的高血压,起源于小阻力动脉的结构变化。PAH的定义特征是肺动脉(PA)的不适当重塑,导致右心室衰竭和死亡。尽管PAH的治疗有所改善,患者的长期预后仍然很差,需要更有效的目标。
■通过微阵列分析基因表达,RNA测序,定量聚合酶链反应,西方印迹,在多种肺动脉高压(PH)和人类PAH的小鼠和大鼠模型中对肺和分离的PA进行免疫染色。通过数字超声评估PH,血液动力学测量,和形态计量学。
■高血压大鼠PA转录组的微阵列分析确定了一种新的候选物,PBK(PDZ结合激酶),这在包括人类在内的多个模型和物种中被上调。PBK是在细胞增殖中具有重要作用的丝氨酸/苏氨酸激酶,其在正常组织中最低限度地表达,但在高度增殖组织中显著增加。PBK在PA的中间层强烈上调,它与平滑肌细胞的标记重叠。获得功能的方法表明,PBK的活性形式增加PA平滑肌细胞增殖,而沉默PBK,显性负PBK,和PBK的药理学抑制剂均减少增殖。PBK的药物抑制剂在小鼠和大鼠模型的PH逆转策略中是有效的,提供翻译意义。在互补的遗传方法中,使用CRISPR/Cas9编辑在大鼠中敲除PBK,PBK的丢失阻止了PH的发展。我们发现PBK与PA平滑肌细胞中的PRC1(胞质分裂蛋白1)结合,并且在PH和人类PAH的实验模型中,参与胞质分裂的多个基因被上调。活性PBK增加了PRC1磷酸化和支持PA平滑肌细胞的胞质分裂,而沉默或显性阴性PBK减少了细胞周期G2/M期的胞质分裂和细胞数量。
■PBK是新描述的PAH靶标,在增殖的PA平滑肌细胞中上调,它通过改变胞质分裂和细胞周期动力学来促进增殖,以促进内侧增厚,纤维化,PA抗性增加,右心室收缩压升高,右心室重构,和PH。
UNASSIGNED: Pulmonary arterial hypertension (PAH) is high blood pressure in the lungs that originates from structural changes in small resistance arteries. A defining feature of PAH is the inappropriate remodeling of pulmonary arteries (PA) leading to right ventricle failure and death. Although treatment of PAH has improved, the long-term prognosis for patients remains poor, and more effective targets are needed.
UNASSIGNED: Gene expression was analyzed by microarray, RNA sequencing, quantitative polymerase chain reaction, Western blotting, and immunostaining of lung and isolated PA in multiple mouse and rat models of pulmonary hypertension (PH) and human PAH. PH was assessed by digital ultrasound, hemodynamic measurements, and morphometry.
UNASSIGNED: Microarray analysis of the transcriptome of hypertensive rat PA identified a novel candidate, PBK (PDZ-binding kinase), that was upregulated in multiple models and species including humans. PBK is a serine/threonine kinase with important roles in cell proliferation that is minimally expressed in normal tissues but significantly increased in highly proliferative tissues. PBK was robustly upregulated in the medial layer of PA, where it overlaps with markers of smooth muscle cells. Gain-of-function approaches show that active forms of PBK increase PA smooth muscle cell proliferation, whereas silencing PBK, dominant negative PBK, and pharmacological inhibitors of PBK all reduce proliferation. Pharmacological inhibitors of PBK were effective in PH reversal strategies in both mouse and rat models, providing translational significance. In a complementary genetic approach, PBK was knocked out in rats using CRISPR/Cas9 editing, and loss of PBK prevented the development of PH. We found that PBK bound to PRC1 (protein regulator of
cytokinesis 1) in PA smooth muscle cells and that multiple genes involved in
cytokinesis were upregulated in experimental models of PH and human PAH. Active PBK increased PRC1 phosphorylation and supported
cytokinesis in PA smooth muscle cells, whereas silencing or dominant negative PBK reduced
cytokinesis and the number of cells in the G2/M phase of the cell cycle.
UNASSIGNED: PBK is a newly described target for PAH that is upregulated in proliferating PA smooth muscle cells, where it contributes to proliferation through changes in
cytokinesis and cell cycle dynamics to promote medial thickening, fibrosis, increased PA resistance, elevated right ventricular systolic pressure, right ventricular remodeling, and PH.