# Effects of Oxidative Stress Gene Protein, Expression, and DNA Methylation on Multiple Sclerosis: A Multi‐Omics Mendelian Randomized Study

## TL;DR

This study uses genetic analysis to find a link between oxidative stress genes and multiple sclerosis, identifying STAT3 and CR1 as key players.

## Contribution

The study introduces a multi-omics Mendelian randomization approach to uncover causal oxidative stress genes in multiple sclerosis.

## Key findings

- STAT3 gene is associated with MS, supported by Level 1 evidence.
- CR1 gene shows an association with MS risk, evidenced by Level 3 support.
- Methylation at specific sites in STAT3 correlates with reduced expression and lower MS risk.

## Abstract

Oxidative stress (OS) is linked to the development of multiple sclerosis (MS), but the causal relationship in terms of genetic pathophysiology remains ambiguous. We employed Mendelian randomization (MR) and colocalization analysis to explore the relationship between OS genes and MS, utilizing an integrative multi‐omics approach.

We obtained data from a genome‐wide association study (GWAS) of MS from the International Multiple Sclerosis Genetics Consortium (Discovery phase) and the FinnGen study (Replication phase). Mendelian randomization analyses were conducted using summary data to evaluate the association between molecular features of OS‐related genes and MS. Additional colocalization analyses were undertaken to ascertain whether the identified signal pairs shared causal genetic variants.

Integration of multi‐omics data, including mQTL‐eQTL and eQTL‐pQTL, revealed that the STAT3 gene is associated with MS, supported by Level 1 evidence. The CR1 gene shows an association with MS risk, evidenced by Level 3 support. Methylation at cg24718015 and cg17833746 in the STAT3 gene correlates with reduced expression of STAT3. At the protein level, high circulating levels of STAT3 are inversely associated with MS risk (OR: 0.43, 95% CI, 0.33–0.54). Elevated levels of TNFRSF1A are also linked with a decreased risk of MS (OR: 0.21; 95% CI, 0.12–0.37), while higher levels of CR1 are positively associated with an increased risk of MS (OR: 1.17; 95% CI, 1.08–1.27).

This study identifies specific OS genes that are associated with MS and enhances our understanding of its pathogenesis.

Mendelian randomization (MR) and colocalization analysis were used to study the relationship between oxidative stress genes and multiple sclerosis by integrating multiple omics, and finally, two significant genes related to STAT3 and CR1 were obtained.