Aging Immune System in Acute Ischemic Stroke: A Transcriptomic Analysis

Abstract

[Figure: see text].

Keywords: aging; immune system; immunosenescence; inflammation; ischemic stroke; leukocytes; stroke outcome.

Figure 1.. Hierarchical cluster plot of genes associated with age in patients with ischemic stroke in (A) Cohort 1 and (B) Cohort 2.

Colour scale below genes on x-axis shows the range in normalized gene expression changes (z-score). Increased gene expression is shown in pink and decreased expression in yellow. Patients are on the y-axis with the lowest age tertile in green (36.4 to 60.8 years) and the highest age tertile in navy blue (73.4 to 90.8 years).

Figure 2.. Gene boxplots (A) and Venn Diagram (B) of age-associated genes found in Cohort 1 and Cohort 2 (P < 0.05, partial correlation coefficient > |0.3|).

(A) Genes differentially expressed with age in both Cohorts 1 and 2. From left to right, top to bottom; BLNK, CCR6, CCR7, CD27, CD79B, CR2, IGHM, NT5E. Cohort 1 (n = 94) is shown in grey and Cohort 2 (n = 79) is shown in orange. Partial correlation coefficients (r) and P values of significance for Cohort 1 range from −0.55 to −0.36 and 2.44 x 10⁻⁸ to 1.62 x 10⁻⁴, respectively, and for Cohort 2 from −0.55 to −0.38 and 2.27 x 10⁻⁷ to 1.33 x 10⁻³, respectively (all P values are adjusted by the Benjamini-Hochberg method). Gene expression on the y-axis is displayed as least square (LS) means with 95% confidence intervals. Gene expression was standardized to a mean of zero and standard deviation of one. (B) Venn diagram of age-associated genes found in Cohort 1 (grey) and Cohort 2 (orange). The total number of genes is indicated and associated gene expression direction (increased or decreased) is indicated with arrows.