Statistics

The primary endpoint of the study is the aneurysmal progression rate. In previous experiments, we observed a mean relative maximal aortic diameter increase of 127.3% ± 36.8 SD for the PPE-model (unpublished data). An aortic diameter difference of 30–33% is considered clinically significant. For a t-test with 5% significance and 80% power, each group needs 13 animals, when the ratio between intervened and control mice is 1:1. Therefore, we used 13–14 mice per group for the two experiments.

Statistical analyses and graphical representation of data were performed using GraphPad Prism version 6.0 (GraphPad Software, San Diego, CA, United States). All normally distributed data passing the D’Agostino and omnibus tests were analyzed by Student’s t-test for two-group comparisons, and significance of change between more than two groups was calculated using one-way analysis of variance (ANOVA) followed by Bonferroni’s post-hoc test for comparing means between groups or using two-way ANOVA with repeated measurements followed by Bonferroni’s post hoc testing. Data are represented as mean ± standard error of mean (SEM). Differences between non-Gaussian data not passing the normality test were analyzed by Mann-Whitney U-test and presented as median with interquartile range.

For normally distributed data, Grubb’s outlier test was used to identify outliers. Here, one sample in the XPro1595-treated-group in the ANGII model was identified as an outlier after analysis of both aortic diameters and surface area of AAAs and was excluded from the statistical analysis and all further downstream analyses. The sample is shown as a red square () in the corresponding figures. A Fisher exact probability test with Freeman-Halton extension was used for a test of statistical significance for contingency table data of elastin degradation grade distributions. Explorative proteomic data were analyzed by unpaired t-test for each protein followed by fdr correction for multiple testing.

Comparisons with P < 0.05 were considered statistically significant and were denoted by asterisk(s).