Fig. 4: Plasma levels of GDNF and CCL25 correlate with blood glucose in unvaccinated animals (n = 9).

a A correlation matrix depicting the r values between SARS-CoV-2-modulated analytes at week 1, and serum glucose concentrations at various timepoints. Blue-colored correlations = positive correlations and red-colored correlations = negative correlations, dot size denotes size of absolute r value (raw p value correlation matrix in Fig. S4). Spearman’s rank correlation was used for statistical analysis. b Two-sided Spearman’s correlations between plasma CCL19 or GDNF with glucose across baseline, week 1, 4, and 12 in the unvaccinated group, n = 9 animals. c GDNF levels at BL and week 1, 4, 12 in unvaccinated animals (n = 9) p.i. Statistical significance was determined using the two-sided Wilcoxon matched-pairs signed-rank test. d Two-sided Spearman’s correlations between plasma CCL19 and GDNF across baseline, week 1, 4, and 12 in the unvaccinated group. e Comparative analysis showing plasma GDNF levels in unvaccinated (n = 10) and vaccinated (n = 5) animals at baseline (BL) and weeks 1–3. Error bars represent mean with SD. Statistical comparison performed using two-sided Wilcoxon matched pairs signed-rank test. f Two-sided Spearman correlation between blood glucose and insulin across baseline, week 1, 4, 8, 12, and 16 p.i. in the unvaccinated group. ELISA for insulin was conducted in triplicates for each animal. g Unbiased STRING analysis, using custom setting with GDNF as the sole input. h BioGRID protein-protein analysis tool using customs settings and Homo sapiens database used to validate GDNF interactions (proteins of interest highlighted by arrows). n denotes number of independent samples/animals at each timepoint. Source data are provided as a Source Data file.