IL-6R Protective Variant rs7529229 Reduces Interleukin-6 Signaling and Contributes To A Decreased Ischemic Stroke Risk

Abstract Background Interleukin-6 (IL-6) signaling is associated with an increased risk of coronary artery disease (CAD) and ischemic stroke (IS). Growing evidence shows that the minor alleles of IL-6 receptor gene (IL-6R) variants rs2228145, rs7529229, and rs4129267 significantly increase soluble IL-6R levels and reduce CAD risk. However, the role of IL-6R variants in IS is largely unknown, prompting us to perform a comprehensive analysis. Methods In stage 1 of this study, we performed a meta-analysis of three genome-wide association study datasets from MEGASTROKE, UK Biobank, and the Million Veteran Program to evaluate the association of rs7529229 with IS. In stage 2, we conducted an expression quantitative trait loci analysis to examine the effects of rs7529229 on IL-6R expression in neuropathologically healthy individuals from the UK Brain Expression Consortium, GTEx project, and the eQTLGen Consortium. In stage 3, we used a tissue-specific gene expression analysis to evaluate differences in IL-6R expression across human tissues using gene expression data from GTEx. In stage 4, we conducted a case–control gene expression analysis to explore the differential expression of IL-6R in the whole blood of IS patients and healthy controls. Results We found that: (1) the rs7529229 minor allele significantly reduced the risk of developing IS (odds ratio=0.97, 95% confidence interval 0.95–0.99, P=2.30E-03); (2) the rs7529229 minor allele significantly reduced IL-6R expression in relevant tissues especially in blood vessels and whole blood; (3) IL-6R was mainly expressed in skeletal muscle and whole blood; and (4) IL-6R expression was significantly reduced in the whole blood of healthy controls compared with IS patients. Importantly, the biological senses in stages 1–4 were all convergent. Conclusions Taken together, our findings indicate that the rs7529229 minor allele decreases IL-6R expression in relevant tissues, diminishes IL-6 signaling, and eventually reduces the IS risk. Hence, IL-6R may be a potential therapeutic target for IS. Tocilizumab, a monoclonal antibody that blocks both membrane-bound and circulating IL-6R, might be effective in treating IS or lowering its risk of development, so warrants further testing in suitably powered randomized controlled trials.

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IL-6R protective variant rs7529229 reduces interleukin-6 signaling and contributes to decreased ischemic stroke risk

10.21203/rs.3.rs-37472/v1 ◽

2020 ◽

Author(s):

Haihua Zhang ◽

Wenbo Zhao ◽

Bian Liu ◽

Tao Wang ◽

Zhifa Han ◽

...

Keyword(s):

Gene Expression ◽

Ischemic Stroke ◽

Expression Analysis ◽

Interleukin 6 ◽

Whole Blood ◽

Gene Expression Analysis ◽

Minor Allele ◽

Healthy Controls ◽

Increased Risk ◽

Stage 1

Abstract BackgroundInterleukin-6 (IL-6) signaling is associated with the increased risk of coronary artery disease (CAD) and ischemic stroke (IS). Growing evidence shows that the minor allele of IL-6R rs7529229 variant could significantly increase the soluble IL-6 receptor levels and reduce CAD risk. However, it is largely unknown about the role of rs7529229 in IS, which promotes us to perform a comprehensive analysis. MethodsIn stage 1, we performed a meta-analysis of three GWAS datasets from MEGASTROKE, UK Biobank, and Million Veteran Program to evaluate the association of rs7529229 with IS. In stage 2, we conducted an expression quantitative trait loci analysis to examine the effects of rs7529229 on IL-6R expression in neuropathologically normal individuals from UK Brain Expression Consortium, GTEx project and eQTLGen Consortium. In stage 3, a tissue-specific gene expression analysis is used to evaluate the potential difference of IL-6R expression across the human tissues using gene expression data from GTEx. In stage 4, a case-control gene expression analysis is used to explore the potentially differential expression of IL-6R in IS and healthy controls in whole blood. ResultsOur results show that (1) rs7529229 minor allele could significantly reduce the risk of IS (OR=0.97, 95% CI 0.95-0.99, P=2.30E-03); (2) rs7529229 minor allele could significantly reduce IL-6R expression in relevant tissues especially in blood vessels and whole blood; (3) IL-6R is mainly expressed in skeletal muscle and whole blood; (4) expression of IL-6R is significantly reduced in healthy controls compared with IS cases in whole blood. Importantly, the biological senses in stage 1-4 are all convergent. ConclusionsCollectively, these findings indicate that rs7529229 minor allele may first reduce IL-6R expression in relevant tissues, further reduce IL-6 signaling, and eventually reduce the IS risk. Hence, IL-6R may be a potential therapeutic target, and blocking IL-6 signaling might be effective in treatment of IS.

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Comparison of phenol-based and alternative RNA isolation methods for gene expression analyses

Journal of the Serbian Chemical Society ◽

10.2298/jsc091223084j ◽

2010 ◽

Vol 75 (8) ◽

pp. 1053-1061 ◽

Cited By ~ 2

Author(s):

Ksenija Jakovljevic ◽

Milena Spasic ◽

Emina Malisic ◽

Jelena Dobricic ◽

Ana Krivokuca ◽

...

Keyword(s):

Gene Expression ◽

Expression Analysis ◽

Whole Blood ◽

Gene Expression Analysis ◽

Expression Patterns ◽

Rna Extraction ◽

Rna Isolation ◽

Specific Gene ◽

Isolation Methods ◽

Gene Expression Analyses

The widespread use of gene expression analyses has been limited by the lack of a critical evaluation of the methods used to extract nucleic acids from human tissues. For evaluating gene expression patterns in whole blood or leukocytes, the method of RNA isolation needs to be considered as a critical variable in the design of the experiment. Quantitative real-time PCR (qPCR) is widely used for the quantification of gene expression in today?s clinical practice. Blood samples as a preferred RNA source for qPCR should be carefully handled and prepared to not inhibit gene expression analyses. The present study was designed to compare the frequently used guanidine thiocyanate-phenol-chloroformbased method (TRI Reagent?) with two alternative RNA isolation methods (6100 PrepStation and QIAamp?) from whole blood or leukocytes for the purpose of gene expression analysis in chronic myeloid leukemia (CML) patients. Based on the results of this study, for the best combination of yield and RNA extraction purity, taking into account the necessary amount of the clinical sample and performance time, the protocol using phenol-based TRI Reagent? for RNA extraction from leukocytes is suggested as the most suitable protocol for this specific gene expression analysis.

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