Department of Hepatobiliary Surgery, Affiliated Hospital of Guizhou Medical University, Yunyan District, Guiyang, P.R. China.
Eur Rev Med Pharmacol Sci. 2019 Aug;23(15):6645-6656. doi: 10.26355/eurrev_201908_18555.
Hepatopulmonary syndrome (HPS) is a kind of pulmonary microvascular disease and occurs in 15%-30% cirrhosis. This study aimed to investigate the effects of pulmonary CX3CR1 on angiogenesis and associated mechanisms in HPS animal models.
CX3CR1GFP/GFP mice were constructed by replacing CX3CR1 with GFP. Common bile duct ligation (CBDL) mouse model was established with surgery. Release of nitric oxide (NO) was evaluated. Hematoxylin-eosin (HE) staining was employed to examine the inflammation of lung tissues. CD31 expression was detected with immunohistochemistry assay. Western blotting was used to evaluate the expression of CX3CL1, CX3CR1, phosphorylated-AKT (p-AKT), phosphorylated-ERK (p-ERK). Quantitative Real Time-PCR (qRT-PCR) assay was used to examine VEGF, PDGF, iNOS, eNOS, and HO-1 expression.
CX3CR1-deficiency (CX3CR1GFP/GFP-sham or CX3CR1GFP/GFP-CBDL mice) significantly reduced NO release compared to wide type (WT)-mice or WT-CBDL mice (p<0.05). CX3CR1-deficiency significantly alleviated inflammation compared to wide type (WT)-mice or WT-CBDL mice (p<0.05). CX3CR1-deficiency significantly reduced CD31 expression compared to WT-sham and WT-CBDL mice, respectively (p<0.05). CX3CR1 also participated in anti-angiogenesis efficacy of Bevacizumab. CX3CR1-deficiency significantly down-regulated the ratio of p-AKT/AKT and p-ERK/ERK and inhibited the secretion of VEGF and PDGF compared to WT-mice (p<0.05). CX3CR1-deficiency significantly reduced iNOS, eNOS, and HO-1 expression compared to WT-mice (p<0.05).
CX3CR1 deficiency reduced VEGF and PDGF production, inhibited p-AKT, and p-ERK activation and down-regulated iNOS, eNOS, and HO-1 expression. Therefore, CX3CR1 participates in pulmonary angiogenesis in the experimental HPS mice via inhibiting AKT/ERK signaling pathway and regulating NO/NOS release. These findings would provide a potential insight for clarifying the pathological mechanisms of HPS.
肝肺综合征（HPS）是一种肺微血管疾病，发生于 15%-30%的肝硬化患者中。本研究旨在探讨 CX3CR1 在 HPS 动物模型中的肺血管生成作用及其相关机制。
构建了 CX3CR1-GFP/GFP 小鼠，通过取代 CX3CR1 来构建 GFP。通过手术建立胆总管结扎（CBDL）小鼠模型。评估一氧化氮（NO）的释放。采用苏木精-伊红（HE）染色观察肺组织的炎症。免疫组织化学检测 CD31 表达。Western blot 检测 CX3CL1、CX3CR1、磷酸化-AKT（p-AKT）、磷酸化-ERK（p-ERK）的表达。实时定量 PCR（qRT-PCR）检测 VEGF、PDGF、iNOS、eNOS 和 HO-1 的表达。
与野生型（WT）-小鼠或 WT-CBDL 小鼠相比，CX3CR1 缺陷（CX3CR1GFP/GFP-假手术或 CX3CR1GFP/GFP-CBDL 小鼠）显著降低了 NO 的释放（p<0.05）。与野生型（WT）-小鼠或 WT-CBDL 小鼠相比，CX3CR1 缺陷显著减轻了炎症（p<0.05）。与 WT-假手术和 WT-CBDL 小鼠相比，CX3CR1 缺陷显著降低了 CD31 的表达（p<0.05）。CX3CR1 还参与了贝伐单抗的抗血管生成作用。与 WT 小鼠相比，CX3CR1 缺陷显著下调了 p-AKT/AKT 和 p-ERK/ERK 的比值，并抑制了 VEGF 和 PDGF 的分泌（p<0.05）。与 WT 小鼠相比，CX3CR1 缺陷显著降低了 iNOS、eNOS 和 HO-1 的表达（p<0.05）。
CX3CR1 缺失减少了 VEGF 和 PDGF 的产生，抑制了 p-AKT 和 p-ERK 的激活，并下调了 iNOS、eNOS 和 HO-1 的表达。因此，CX3CR1 通过抑制 AKT/ERK 信号通路和调节 NO/NOS 释放参与实验性 HPS 小鼠的肺血管生成。这些发现为阐明 HPS 的病理机制提供了潜在的见解。
