Peking University First Hospital, Beijing, China.
Oklahoma Medical Research Foundation, Oklahoma City.
Arthritis Rheumatol. 2018 Feb;70(2):287-297. doi: 10.1002/art.40353. Epub 2018 Jan 9.
Recent evidence from genetic, cell biology, and animal model studies has suggested a pivotal role of autophagy in mediating systemic lupus erythematosus (SLE). However, the genetic basis has not yet been thoroughly examined. Therefore, the aim of the present study was to identify additional susceptibility variants in autophagy-related genes along with their functional significance.
First, we performed a gene family-based genetic association analysis in SLE patients with the use of ImmunoChip arrays, and then we selected the most strongly associated polymorphisms for replication in additional cohorts. To identify regulatory clues, we analyzed publicly available blood expression quantitative trait locus data and Encyclopedia of DNA Elements data on transcription factor binding sites and cell type-specific differential expression. Functional effects were tested by luciferase reporter assays, electrophoretic mobility shift assays, and differential gene expression assays.
In 14,474 samples, we observed that the rare Chinese variant rs933717T was associated with susceptibility to SLE (0.11% in cases versus 0.87% in controls; P = 2.36 × 10 , odds ratio 0.13). The rs933717 risk allele C correlated with increased MAP1LC3B expression; increased MAP1LC3B messenger RNA was observed in SLE patients and in lupus-prone mice. In reporter gene constructs, the risk allele increased luciferase activity up to 2.7-3.8-fold in both HEK 293T and Jurkat cell lines, and the binding of HEK 293T and Jurkat cell nuclear extracts to the risk allele was also increased.
We observed a likely genetic association between light chain 3B, a widely used marker for autophagy, and susceptibility to SLE.
遗传、细胞生物学和动物模型研究的最新证据表明，自噬在介导系统性红斑狼疮（SLE）中起着关键作用。然而，其遗传基础尚未得到彻底研究。因此，本研究旨在鉴定自噬相关基因中的其他易感变异及其功能意义。
首先，我们使用免疫芯片阵列对 SLE 患者进行了基因家族遗传关联分析，然后选择与其他队列复制最相关的多态性。为了确定调控线索，我们分析了公共可用的血液表达数量性状基因座数据和 DNA 元件百科全书数据，以分析转录因子结合位点和细胞类型特异性差异表达。通过荧光素酶报告基因检测、电泳迁移率变动分析和差异基因表达检测来测试功能效应。
在 14474 个样本中，我们观察到罕见的中国变体 rs933717T 与 SLE 的易感性相关（病例中为 0.11%，对照中为 0.87%；P=2.36×10 ，优势比 0.13）。rs933717 风险等位基因 C 与 MAP1LC3B 表达增加相关；SLE 患者和狼疮易感小鼠中观察到 MAP1LC3B 信使 RNA 增加。在报告基因构建体中，风险等位基因在 HEK 293T 和 Jurkat 细胞系中的荧光素酶活性增加了 2.7-3.8 倍，HEK 293T 和 Jurkat 细胞核提取物与风险等位基因的结合也增加了。
我们观察到轻链 3B（自噬的常用标志物）与 SLE 易感性之间可能存在遗传关联。
