Department of Radiation Oncology, Zhongshan Hospital , Fudan University , Shanghai 200032 , China.
Department of Radiation Oncology, Nanfang Hospital , Southern Medical University , Guangzhou 510515 , China.
J Proteome Res. 2019 Jan 4;18(1):508-521. doi: 10.1021/acs.jproteome.8b00814. Epub 2018 Dec 10.
Hepatic stellate cells (HSCs) are the main target of radiation damage and primarily contribute to the development of radiation-induced liver fibrosis. However, the molecular events underlying the radiation-induced activation of HSCs are not fully elucidated. In the present study, human HSC line LX2 was treated with X-ray irradiation and/or TGF-β1, and profibrogenic molecules were evaluated. The iTRAQ LC-MS/MS technology was performed to identify global protein expression profiles in LX2 following exposure to different stimuli. Irradiation or TGF-β1 alone increased expression of α-SMA, collagen 1, CTGF, PAI-1, and fibronectin. Irradiation and TGF-β1 cooperatively induced expression of these profibrotic markers. In total, 102, 137, 155 dysregulated proteins were identified in LX2 cell samples affected by irradiation, TGF-β1, or cotreatment, respectively. Bioinformatic analyses showed that the three differentially expressed protein sets were commonly associated with cell cycle and protein processing in endoplasmic reticulum. The expression of a set of proteins was properly validated: CDC20, PRC1, KIF20A, CCNB1, SHCBP, TACC3 were upregulated upon irradiation or irradiation and TGF-β1 costimulation, whereas SPARC and THBS1 were elevated by TGF-β1 or TGF-β1 plus irradiation treatment. Furthermore, CDC20 inhibition suppressed expression of profibrotic markers in irradiated and TGF-β1-stimulated LX2 cells. Detailed data on potential molecular mechanisms causing the radiation-induced HSC activation presented here would be instrumental in developing radiotherapy strategies that minimize radiation-induced liver fibrosis.
肝星状细胞（HSCs）是辐射损伤的主要靶标，主要导致辐射诱导的肝纤维化的发展。然而，辐射诱导的 HSCs 激活的分子事件尚未完全阐明。在本研究中，用人 HSC 系 LX2 用 X 射线照射和/或 TGF-β1 处理，并评估了致纤维化分子。采用 iTRAQ LC-MS/MS 技术鉴定了 LX2 在暴露于不同刺激后的全局蛋白表达谱。单独照射或 TGF-β1 均可增加 α-SMA、胶原 1、CTGF、PAI-1 和纤维连接蛋白的表达。照射和 TGF-β1 协同诱导这些致纤维化标志物的表达。共鉴定出 102、137、155 个差异表达蛋白在受照射、TGF-β1 或联合处理影响的 LX2 细胞样本中。生物信息学分析表明，这三组差异表达蛋白集均与细胞周期和内质网中的蛋白质加工有关。一组蛋白质的表达得到了适当的验证：CDC20、PRC1、KIF20A、CCNB1、SHCBP、TACC3 在照射或照射和 TGF-β1 共刺激下上调，而 SPARC 和 THBS1 则在 TGF-β1 或 TGF-β1 加照射处理下升高。此外，CDC20 抑制抑制了辐照和 TGF-β1 刺激的 LX2 细胞中致纤维化标志物的表达。这里提供的关于导致辐射诱导的 HSC 激活的潜在分子机制的详细数据，将有助于开发最大限度减少辐射诱导的肝纤维化的放射治疗策略。
