Department of Neurology, Washington University School of Medicine, St Louis, Missouri.
Department of Psychiatry, Washington University School of Medicine, St Louis, Missouri.
JAMA Neurol. 2014 Apr;71(4):449-53. doi: 10.1001/jamaneurol.2013.6237.
Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease in which microglia play a significant and active role. Recently, a rare missense variant (p.R47H) in the microglial activating gene TREM2 was found to increase the risk of several neurodegenerative diseases, including Alzheimer disease. Whether the p.R47H variant is a risk factor for ALS is not known.
To determine whether p.R47H (rs75932628) in TREM2 is a risk factor for ALS and assess whether TREM2 expression is dysregulated in disease.
DESIGN, SETTING, AND PARTICIPANTS: Samples of DNA from 923 individuals with sporadic ALS and 1854 healthy control individuals self-reported as non-Hispanic white were collected from ALS clinics in the United States and genotyped for the p.R47H variant in TREM2. Clinical data were obtained on ALS participants for genotype/phenotype correlations. Expression of TREM2 was measured by quantitative polymerase chain reaction and compared in spinal cord samples from 18 autopsied patients with ALS and 12 neurologically healthy controls, as well as from wild-type and transgenic SOD1G93A mice.
Minor allele frequency of rs75932628 and relative expression of TREM2.
The TREM2 variant p.R47H was more common in patients with ALS than in the controls and is therefore a significant risk factor for ALS (odds ratio, 2.40; 95% CI, 1.29-4.15; P = 4.1×10-3). Furthermore, TREM2 expression was increased in spinal cord samples from ALS patients and SOD1G93A mice (P = 2.8×10-4 and P = 2.8×10-9, respectively), confirming dysregulated TREM2 in disease. Expression of TREM2 in the human spinal cord was negatively correlated with survival (P = .04) but not with other phenotypic aspects of disease.
This study demonstrates that the TREM2 p.R47H variant is a potent risk factor for sporadic ALS. To our knowledge, these findings identify the first genetic influence on neuroinflammation in ALS and highlight the TREM2 signaling pathway as a therapeutic target in ALS and other neurodegenerative diseases.
肌萎缩侧索硬化症(ALS)是一种致命的神经退行性疾病,其中小胶质细胞发挥着重要且活跃的作用。最近,在小胶质细胞激活基因 TREM2 中发现了一种罕见的错义变体(p.R47H),它会增加包括阿尔茨海默病在内的几种神经退行性疾病的风险。但是,p.R47H 变体是否是 ALS 的风险因素尚不清楚。
确定 TREM2 中的 p.R47H(rs75932628)是否是 ALS 的危险因素,并评估疾病中是否存在 TREM2 表达失调。
设计、地点和参与者:从美国的 ALS 诊所收集了 923 名散发型 ALS 患者和 1854 名健康对照个体的 DNA 样本,这些个体自我报告为非西班牙裔白人,并对 TREM2 中的 p.R47H 变体进行了基因分型。对 ALS 参与者的临床数据进行了基因型/表型相关性的分析。通过定量聚合酶链反应测量 TREM2 的表达,并在 18 名尸检 ALS 患者和 12 名神经健康对照的脊髓样本以及野生型和转基因 SOD1G93A 小鼠中进行比较。
rs75932628 的次要等位基因频率和 TREM2 的相对表达。
与对照组相比,ALS 患者中 TREM2 变体 p.R47H 更为常见,因此是 ALS 的重要危险因素(优势比,2.40;95%CI,1.29-4.15;P=4.1×10-3)。此外,ALS 患者和 SOD1G93A 小鼠的脊髓样本中 TREM2 的表达增加(P=2.8×10-4 和 P=2.8×10-9),证实了疾病中 TREM2 的失调表达。人类脊髓中 TREM2 的表达与生存呈负相关(P=0.04),但与疾病的其他表型方面无关。
这项研究表明,TREM2 p.R47H 变体是散发型 ALS 的一个强有力的危险因素。据我们所知,这些发现首次确定了对 ALS 神经炎症的遗传影响,并强调了 TREM2 信号通路作为 ALS 和其他神经退行性疾病的治疗靶点。