Assessing chaperone for Zn, Cu-superoxide dismutase as an indicator of copper deficiency in malnourished children

Abstract

It is not clear how frequent is copper deficiency in humans. Current copper markers are not sensitive enough to detect early copper deficiency and new markers are needed. CCS is a candidate to become a copper biomarker. Objective: Measuring CCS mRNA relative expression in malnourished children and compare results (a) with those of the same children after nutritional recovery and (b) with well-nourished children. Method: On admission to the protocol and after 15 day nutritional treatment, severely (G1 = 18) and moderately (G2 = 10) malnourished children were compared with well-nourished healthy controls (G3 = 15), measuring anthropometric indicators, blood biochemistry, Cu, Fe and Zn serum concentrations, ceruloplasmin, C Reactive protein and mRNA abundance of CCS, SOD and MT2 in peripheral mononuclear cells. Result: In malnourished groups, mean serum copper concentration was below the cut-off on admission to hospital and increased after 15 days (t-test, p < 0.01). On admission to protocol, CCS mRNA abundance in G1 and G2 was higher than in G3 (one way ANOVA, p < 0.001). After 15 days, CCS expression decreased as expected (t-test, p < 0.001). Initial SOD mRNA relative abundance was higher in study groups than controls and also between G1 and G2 (One way ANOVA, both p < 0.01); after 15 days, G1 and G2 were not different (t-test, NS). MT2A abundance of transcripts did not follow a clear change pattern. Conclusion: CCS mRNA abundance responded as expected, being higher in malnourished children than in controls; nutritional recovery in these latter resulted in decreasing expression of the chaperone, supporting the hypothesis that CCS may be a copper biomarker.