Gomez-Pinedo U, Matías-Guiu J A, Torre-Fuentes L, Montero-Escribano P, Hernández-Lorenzo L, Pytel V, Maietta P, Alvarez S, Sanclemente-Alamán I, Moreno-Jimenez L, Ojeda-Hernandez D, Villar-Gómez N, Benito-Martin M S, Selma-Calvo B, Vidorreta-Ballesteros L, Madrid R, Matías-Guiu J
Laboratory of Neurobiology, Institute of Neurosciences, IdISSC, Hospital Clínico San Carlos, Universidad Complutense de Madrid, Madrid, Spain.
Department of Neurology, Institute of Neurosciences, IdISSC, Hospital Clínico San Carlos, Universidad Complutense de Madrid, Madrid, Spain.
Neurologia (Engl Ed). 2025 Jan-Feb;40(1):10-21. doi: 10.1016/j.nrleng.2022.07.002. Epub 2022 Aug 10.
Genomic studies have identified numerous genetic variants associated with susceptibility to multiple sclerosis (MS); however, each one explains only a small percentage of the risk of developing the disease. These variants are located in genes involved in specific pathways, which supports the hypothesis that the risk of developing MS may be linked to alterations in these pathways, rather than in specific genes. We analyzed the role of the TNFRSF1A gene, which encodes one of the TNF-α receptors involved in a signaling pathway previously linked to autoimmune disease.
We included 138 individuals from 23 families including at least 2 members with MS, and analyzed the presence of exonic variants of TNFRSF1A through whole-exome sequencing. We also conducted a functional study to analyze the pathogenic mechanism of variant rs4149584 (-g.6442643C > G, NM_001065.4:c.362 G > A, R92Q) by plasmid transfection into human oligodendroglioma (HOG) cells, which behave like oligodendrocyte lineage cells; protein labeling was used to locate the protein within cells. We also analyzed the ability of transfected HOG cells to proliferate and differentiate into oligodendrocytes.
Variant rs4149584 was found in 2 patients with MS (3.85%), one patient with another autoimmune disease (7.6%), and in 5 unaffected individuals (7.46%). The 2 patients with MS and variant rs4149584 were homozygous carriers and belonged to the same family, whereas the remaining individuals presented the variant in heterozygosis. The study of HOG cells transfected with the mutation showed that the protein does not reach the cell membrane, but rather accumulates in the cytoplasm, particularly in the endoplasmic reticulum and near the nucleus; this suggests that, in the cells presenting the mutation, TNFRSF1 does not act as a transmembrane protein, which may alter its signaling pathway. The study of cell proliferation and differentiation found that transfected cells continue to be able to differentiate into oligodendrocytes and are probably still capable of producing myelin, although they present a lower rate of proliferation than wild-type cells.
Variant rs4149584 is associated with risk of developing MS. We analyzed its functional role in oligodendrocyte lineage cells and found an association with MS in homozygous carriers. However, the associated molecular alterations do not influence the differentiation into oligodendrocytes; we were therefore unable to confirm whether this variant alone is pathogenic in MS, at least in heterozygosis.
基因组研究已鉴定出众多与多发性硬化症（MS）易感性相关的基因变异；然而，每一种变异仅能解释该疾病发病风险的一小部分。这些变异位于参与特定信号通路的基因中，这支持了MS发病风险可能与这些信号通路的改变相关，而非特定基因改变相关的假说。我们分析了肿瘤坏死因子受体超家族1A（TNFRSF1A）基因的作用，该基因编码一种参与先前与自身免疫性疾病相关的信号通路的肿瘤坏死因子-α（TNF-α）受体。
我们纳入了来自23个家庭的138名个体，其中至少有2名家庭成员患有MS，并通过全外显子测序分析了TNFRSF1A外显子变异的存在情况。我们还进行了一项功能研究，通过将质粒转染到人少突胶质细胞瘤（HOG）细胞（其行为类似于少突胶质细胞系细胞）来分析变异rs4149584（-g.6442643C>G，NM_001065.4:c.362G>A，R92Q）的致病机制；使用蛋白质标记来定位细胞内的蛋白质。我们还分析了转染后的HOG细胞增殖和分化为少突胶质细胞的能力。
在2例MS患者（3.85%）、1例患有另一种自身免疫性疾病的患者（7.6%）和5名未受影响的个体（7.46%）中发现了变异rs4149584。2例携带变异rs4149584的MS患者为纯合子携带者，且属于同一家族，而其余个体为杂合子携带该变异。对转染了该突变的HOG细胞的研究表明，该蛋白质未到达细胞膜，而是积聚在细胞质中，特别是在内质网和细胞核附近；这表明，在存在该突变的细胞中，TNFRSF1不作为跨膜蛋白发挥作用，这可能会改变其信号通路。细胞增殖和分化研究发现，转染后的细胞仍能够分化为少突胶质细胞，并且可能仍有能力产生髓磷脂，尽管它们的增殖速率低于野生型细胞。
变异rs4149584与MS发病风险相关。我们分析了其在少突胶质细胞系细胞中的功能作用，并发现纯合子携带者与MS有关联。然而，相关的分子改变并不影响向少突胶质细胞的分化；因此，我们无法确定该变异单独是否在MS中具有致病性，至少在杂合子状态下如此。
