Causal associations between circulating inflammatory cytokines and blinding eye diseases: a bidirectional Mendelian randomization analysis

Menghao Teng; Jiachen Wang; Xiaochen Su; Ye Tian; Xiaomin Ye; Yingang Zhang

doi:10.3389/fnagi.2024.1324651

Causal associations between circulating inflammatory cytokines and blinding eye diseases: a bidirectional Mendelian randomization analysis

Front Aging Neurosci. 2024 Jan 23:16:1324651. doi: 10.3389/fnagi.2024.1324651. eCollection 2024.

Authors

Menghao Teng^#¹, Jiachen Wang^#², Xiaochen Su¹, Ye Tian³, Xiaomin Ye⁴, Yingang Zhang¹

Affiliations

¹ Department of Orthopedics, The First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, China.
² Department of Joint Surgery, HongHui Hospital, Xi'an Jiaotong University, Xi'an, China.
³ Healthy Food Evaluation Research Center, West China School of Public Health and West China Fourth Hospital, Sichuan University, Chengdu, China.
⁴ School of Electronic Information and Artiffcial Intelligence, Shaanxi University of Science and Technology, Xi'an, China.

^# Contributed equally.

Abstract

Background: Previous studies have explored the associations between circulating inflammatory cytokines and blinding eye diseases, including glaucoma, cataract and macular degeneration. However, the causality of these associations remains controversial. This study employs a bidirectional Mendelian randomization (MR) study to investigate the causal relationships between 41 circulating inflammatory cytokines and these blinding eye diseases.

Methods: Summary data for glaucoma, cataract, macular degeneration and 41 circulating inflammatory cytokines were publicly available. The inverse variance weighted (IVW) method was employed as the main analysis method. Additionally, various sensitivity tests, including MR-Egger regression, weighted median, weight mode, Cochran's Q test, MR pleiotropy Residual Sum and Outlier test, and leave-one-out test, were conducted to evaluate sensitivity and stability of results.

Results: The IVW analysis identified six circulating inflammatory cytokines causally associated with the risk of blinding eye diseases: Monokine induced by interferon-gamma (MIG) for glaucoma, interleukin-1 receptor antagonist (IL-1ra), IL-6, IL-10, and platelet derived growth factor BB (PDGFbb) for cataract, and MIG and hepatocyte growth factor (HGF) for macular degeneration. However, it is noteworthy that none of these associations remained significant after Bonferroni correction (p < 0.0004). Reverse MR analyses indicated that cataract may lead to a decrease in vascular endothelial growth factor (VEGF) levels (OR: 3.326 × 10^-04, 95% CI: 5.198 × 10^-07 - 2.129 × 10^-01, p = 0.0151).

Conclusion: This study highlights the potential roles of specific inflammatory cytokines in the development of glaucoma, cataract and macular degeneration. Moreover, it suggests that VEGF is likely to be involved in cataract development downstream. These findings offer insights for early prevention and novel therapeutic strategies for these blinding eye diseases.

Keywords: cataract; circulating inflammatory cytokines; genome-wide association study; glaucoma; macular degeneration; mendelian randomization.

Grants and funding

The author(s) declare financial support was received for the research, authorship, and/or publication of this article. This work was supported by the Shaanxi Provincial Administration of Traditional Chinese Medicine (No. 2021-04-ZZ-003). Financial support had no impact on the outcomes of this study.