Bai Yang, Li Zhong-Xia, Wang Huai-Liang, Lian Guo-Chao, Wang Yun
Department of Clinical Pharmacology, College of Pharmacy, China Medical University, Shenyang, Liaoning 110122, P.R. China.
Department of Orthopaedic Surgery, Central Hospital Affiliated to Shenyang Medical College, Shenyang, Liaoning 110000, P.R. China.
Int J Mol Med. 2017 Jul;40(1):155-163. doi: 10.3892/ijmm.2017.3001. Epub 2017 May 26.
Inflammation and remodeling play a role in the pathogenesis of pulmonary arterial hypertension (PAH). Nuclear factor-κB (NF-κB) and nuclear factor of activated T cells-1 (NFAT-1) participate in inflammation and remodeling in a number of diseases. As a tryptophan hydroxylase inhibitor, 4-chloro-DL-phenylalanine (PCPA) had been reported to exert anti-inflammatory and remodeling effects. Therefore, we hypothesized that PCPA may attenuate monocrotaline (MCT)-induced PAH through the NFAT-1 and NF-κB signaling pathways. In order to confirm our hypothesis, we divided 68 Sprague-Dawley male rats into 4 groups as follows: the control, MCT, MCT + P1 and MCT + P2 groups. MCT was administered at a dose of 60 mg/kg once via intraperitoneal injection. PCPA was administered via intraperitoneal injection at a dose of 50 or 100 mg/kg once daily for 21 consecutive days. We then measured the hemodynamic index and morphological analysis was carried out on the lung tissues. Western blot analysis and immunohistochemistry were used to examine the levels of NFAT-1 and NF-κB p-65. The expression levels of phosphorylated inhibitor of NF-κB kinase (p-IKK), IKK, phosphorylated extracellular signal‑regulated kinase (p-ERK), ERK, intercellular adhesion molecule-1 (ICAM-1) and inter-leukin-6 (IL-6) were examined by western blot analysis. MCT was found to significantly induce PAH, with inflammation and remodeling of the lung tissues. This was associatd with an increased expression of NFAT-1, p-IKK, p-ERK and nuclear p65. PCPA significantly attenuated MCT-induced inflammation and arterial remodeling, and decreased the expression of NFAT-1, as well as that of relevant proteins of the NF-κB signaling pathway. The above-mentioned findings suggest that the inhibitory effects of PCPA on MCT-induced inflammation and arterial remodeling are related to the downregulation of the NFAT-1 and NF-κB signaling pathways in rats with PAH.
炎症和重塑在肺动脉高压（PAH）的发病机制中起作用。核因子κB（NF-κB）和活化T细胞核因子-1（NFAT-1）参与多种疾病的炎症和重塑过程。作为一种色氨酸羟化酶抑制剂，4-氯-DL-苯丙氨酸（PCPA）已被报道具有抗炎和抗重塑作用。因此，我们推测PCPA可能通过NFAT-1和NF-κB信号通路减轻野百合碱（MCT）诱导的PAH。为了证实我们的假设，我们将68只Sprague-Dawley雄性大鼠分为4组，如下：对照组、MCT组、MCT + P1组和MCT + P2组。MCT以60 mg/kg的剂量通过腹腔注射给药一次。PCPA以50或100 mg/kg的剂量通过腹腔注射给药，每天一次，连续21天。然后我们测量血流动力学指标，并对肺组织进行形态学分析。采用蛋白质免疫印迹分析和免疫组织化学法检测NFAT-1和NF-κB p-65的水平。通过蛋白质免疫印迹分析检测磷酸化核因子κB抑制激酶（p-IKK）、IKK、磷酸化细胞外信号调节激酶（p-ERK）、ERK、细胞间黏附分子-1（ICAM-1）和白细胞介素-6（IL-6）的表达水平。发现MCT显著诱导PAH，并伴有肺组织的炎症和重塑。这与NFAT-1、p-IKK、p-ERK和核p65的表达增加有关。PCPA显著减轻MCT诱导的炎症和动脉重塑，并降低NFAT-1以及NF-κB信号通路相关蛋白的表达。上述结果表明，PCPA对MCT诱导的炎症和动脉重塑的抑制作用与PAH大鼠中NFAT-1和NF-κB信号通路的下调有关。
