Fig. 3

Zinc status determines primary human PBMC CREM \(\alpha\) expression. Both basal CREM \(\alpha\) protein (A-D) and RNA (E-H) expression in peripheral blood mononuclear cells (PBMC) depending on zinc status is presented. A shows increasing CREM \(\alpha\) protein expression between young controls (n = 22), ZA elderly patients (n = 9) and ZD elderly patients (n = 21), as well as a representative Western blot using CREM \(\alpha\) and β-actin antibodies. Considering these groups pooled, the adjusted zinc diet score (B), serum zinc (both 54 XY pairs) (C), and intracellular labile zinc (53 XY pairs) (D) correlated negatively with CREM \(\alpha\) protein expression. (E) Increased basal CREM \(\alpha\) RNA expression in elderly ZD patients (n = 16) compared to young controls (n = 22) and elderly ZA patients (n = 8) were detected. CREM \(\alpha\) RNA was normalized to the housekeeping gene PBGD. The trend was also confirmed when pooling all groups and plotting the corresponding zinc status indicators against CREM \(\alpha\) RNA expression. CREM \(\alpha\) RNA expression correlates negatively with adjusted zinc diet score (F), serum zinc (both 46 XY pairs) (G) and intracellular labile zinc (45 XY pairs) (H). Data are shown as means + SD. Differences between the three groups in A and E were determined by Kruskal–Wallis and Dunn´s post test. Means not sharing any letter (a or b) are significantly different (p < 0.05). Correlations were determined by the Spearman rank correlation coefficient (r, p < 0.05)