Laboratory of Immunopharmacology, State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, 201203, China.
University of Chinese Academy of Sciences, No.19A Yuquan Road, Beijing, 100049, China.
Arthritis Res Ther. 2019 Jan 29;21(1):40. doi: 10.1186/s13075-019-1820-3.
Glomerulonephritis is one of the major complications and causes of death in systemic lupus erythematosus (SLE) and is characterized by glomerulosclerosis, interstitial fibrosis, and tubular atrophy, along with severe persistent proteinuria. DZ2002 is a reversible S-adenosyl-L-homocysteine hydrolase (SAHH) inhibitor with potent therapeutic activity against lupus nephritis in mice. However, the molecular events underlying the renal protective effects of DZ2002 remained unclear. This study is designed to uncover the molecular mechanisms of DZ2002 on glomerulonephritis of lupus-prone mice.
We conducted a twice-daily treatment of DZ2002 on the lupus-prone NZB/WF1 mice, and the progression of lupus nephritis and alteration of renal function were monitored. The LC-MS-based label-free quantitative (LFQ) proteomic approach was applied to analyze the kidney tissue samples from the normal C57BL/6 mice and the NZB/WF1 mice treated with DZ2002 or vehicle. KEGG pathway enrichment and direct protein-protein interaction (PPI) network analyses were used to map the pathways in which the significantly changed proteins (SCPs) are involved. The selected proteins from proteomic analysis were validated by Western blot analysis and immunohistochemistry in the kidney tissues.
The twice-daily regimen of DZ2002 administration significantly ameliorated the lupus nephritis and improved the renal function in NZB/WF1 mice. A total of 3275 proteins were quantified, of which 253 proteins were significantly changed across normal C57BL/6 mice and the NZB/WF1 mice treated with DZ2002 or vehicle. Pathway analysis revealed that 13 SCPs were involved in tight junction and focal adhesion process. Further protein expression validation demonstrated that DZ2002-treated NZB/WF1 mice exhibited downregulation of α-actinin-4 and integrin-linked kinase (ILK), as well as the restoration of β1-integrin activation in the kidney tissues compared with the vehicle-treated ones.
Our study demonstrated the first evidence for the molecular mechanism of SAHH inhibitor on glomerulonephritis in SLE via the modulation of α-actinin-4 expression and focal adhesion-associated signaling proteins in the kidney.
肾小球肾炎是系统性红斑狼疮（SLE）的主要并发症和死亡原因之一，其特征为肾小球硬化、间质纤维化和管状萎缩，同时伴有严重持续的蛋白尿。DZ2002 是一种可逆的 S-腺苷-L-高半胱氨酸水解酶（SAHH）抑制剂，对狼疮肾炎小鼠具有很强的治疗活性。然而，DZ2002 对肾脏的保护作用的分子事件仍不清楚。本研究旨在揭示 DZ2002 对狼疮易感 NZB/WF1 小鼠肾小球肾炎的分子机制。
我们对狼疮易感 NZB/WF1 小鼠进行了 DZ2002 的每日两次治疗，监测狼疮肾炎的进展和肾功能的改变。应用基于 LC-MS 的无标记定量（LFQ）蛋白质组学方法分析正常 C57BL/6 小鼠和 DZ2002 或载体处理的 NZB/WF1 小鼠的肾脏组织样本。KEGG 途径富集和直接蛋白质-蛋白质相互作用（PPI）网络分析用于映射显著改变的蛋白质（SCPs）所涉及的途径。蛋白质组学分析中选择的蛋白质通过 Western blot 分析和肾脏组织中的免疫组织化学进行验证。
DZ2002 的每日两次给药方案显著改善了 NZB/WF1 小鼠的狼疮肾炎并改善了肾功能。共定量了 3275 种蛋白质，其中 253 种蛋白质在正常 C57BL/6 小鼠和 DZ2002 或载体处理的 NZB/WF1 小鼠中发生显著变化。途径分析表明，13 种 SCPs 参与了紧密连接和粘着斑过程。进一步的蛋白质表达验证表明，与载体处理的 NZB/WF1 小鼠相比，DZ2002 处理的 NZB/WF1 小鼠的肾脏组织中α-辅肌动蛋白-4 和整合素连接激酶（ILK）的表达下调，以及β1-整合素的激活恢复。
我们的研究首次证明了 SAHH 抑制剂通过调节肾脏中α-辅肌动蛋白-4 的表达和粘着斑相关信号蛋白在 SLE 肾小球肾炎中的分子机制。
