Mertens Tinne C J, Hanmandlu Ankit, Tu Ly, Phan Carole, Collum Scott D, Chen Ning-Yuan, Weng Tingting, Davies Jonathan, Liu Chen, Eltzschig Holger K, Jyothula Soma S K, Rajagopal Keshava, Xia Yang, Guha Ashrith, Bruckner Brian A, Blackburn Michael R, Guignabert Christophe, Karmouty-Quintana Harry
Department of Biochemistry and Molecular Biology, McGovern Medical School, The University of Texas Health Science Center at Houston, Houston, TX, United States.
Institut National de la Santé et de la Recherche Médicale UMR_S 999, Le Plessis-Robinson, France.
Front Physiol. 2018 Jun 1;9:555. doi: 10.3389/fphys.2018.00555. eCollection 2018.
Pulmonary hypertension (PH) is a devastating and progressive disease characterized by excessive proliferation of pulmonary artery smooth muscle cells (PASMCs) and remodeling of the lung vasculature. Adenosine signaling through the ADORA2B receptor has previously been implicated in disease progression and tissue remodeling in chronic lung disease. In experimental models of PH associated with chronic lung injury, pharmacological or genetic inhibition of ADORA2B improved markers of chronic lung injury and hallmarks of PH. However, the contribution of ADORA2B expression in the PASMC was not fully evaluated. We hypothesized that adenosine signaling through the ADORA2B receptor in PASMC mediates the development of PH. PASMCs from controls and patients with idiopathic pulmonary arterial hypertension (iPAH) were characterized for expression levels of all adenosine receptors. Next, we evaluated the development of PH in ADORA2B-Transgelin (Tagln) mice. These mice or adequate controls were exposed to a combination of SUGEN (SU5416, 20 mg/kg/b.w. IP) and hypoxia (10% O) for 28 days (HX-SU) or to chronic low doses of bleomycin (BLM, 0.035U/kg/b.w. IP). Cardiovascular readouts including right ventricle systolic pressures (RVSPs), Fulton indices and vascular remodeling were determined. Using PASMCs we identified ADORA2B-dependent mediators involved in vascular remodeling. These mediators: IL-6, hyaluronan synthase 2 (HAS2) and tissue transglutaminase (Tgm2) were determined by RT-PCR and validated in our HX-SU and BLM models. Increased levels of ADORA2B were observed in PASMC from iPAH patients. ADORA2B-Tagln mice were protected from the development of PH following HX-SU or BLM exposure. In the BLM model of PH, ADORA2B- Tagln mice were not protected from the development of fibrosis. Increased expression of IL-6, HAS2 and Tgm2 was observed in PASMC in an ADORA2B-dependent manner. These mediators were also reduced in ADORA2B- Tagln mice exposed to HX-SU or BLM. Our studies revealed ADORA2B-dependent increased levels of IL-6, hyaluronan and Tgm2 in PASMC, consistent with reduced levels in ADORA2B- Tagln mice exposed to HX-SU or BLM. Taken together, our data indicates that ADORA2B on PASMC mediates the development of PH through the induction of IL-6, hyaluronan and Tgm2. These studies point at ADORA2B as a therapeutic target to treat PH.
肺动脉高压（PH）是一种具有破坏性的进行性疾病，其特征是肺动脉平滑肌细胞（PASMCs）过度增殖和肺血管重塑。通过ADORA2B受体的腺苷信号传导先前已被认为与慢性肺病的疾病进展和组织重塑有关。在与慢性肺损伤相关的PH实验模型中，ADORA2B的药理学或基因抑制改善了慢性肺损伤的标志物和PH的特征。然而，PASMC中ADORA2B表达的作用尚未得到充分评估。我们假设PASMC中通过ADORA2B受体的腺苷信号传导介导了PH的发展。对来自对照组和特发性肺动脉高压（iPAH）患者的PASMC进行了所有腺苷受体表达水平的表征。接下来，我们评估了ADORA2B-转胶蛋白（Tagln）小鼠中PH的发展。将这些小鼠或适当的对照组暴露于SUGEN（SU5416，20mg/kg体重，腹腔注射）和低氧（10%氧气）的组合中28天（HX-SU），或暴露于慢性低剂量博来霉素（BLM，0.035U/kg体重，腹腔注射）。测定了包括右心室收缩压（RVSPs）、富尔顿指数和血管重塑在内的心血管指标。我们使用PASMC确定了参与血管重塑的ADORA2B依赖性介质。通过逆转录-聚合酶链反应（RT-PCR）测定了这些介质：白细胞介素-6（IL-6）、透明质酸合酶2（HAS2）和组织转谷氨酰胺酶（Tgm2），并在我们的HX-SU和BLM模型中进行了验证。在iPAH患者的PASMC中观察到ADORA2B水平升高。HX-SU或BLM暴露后，ADORA2B-Tagln小鼠免受PH的发展。在PH的BLM模型中，ADORA2B-Tagln小鼠未免受纤维化的发展。以ADORA2B依赖性方式在PASMC中观察到IL-6、HAS2和Tgm2的表达增加。在暴露于HX-SU或BLM的ADORA2B-Tagln小鼠中，这些介质也减少。我们的研究揭示了PASMC中ADORA2B依赖性的IL-6、透明质酸和Tgm2水平升高，这与暴露于HX-SU或BLM的ADORA2B-Tagln小鼠中水平降低一致。综上所述，我们的数据表明PASMC上的ADORA2B通过诱导IL-6、透明质酸和Tgm2介导了PH的发展。这些研究指出ADORA2B是治疗PH的一个治疗靶点。
