Detectability of secretagogin in human erythrocytes

Secretagogin is a six EF-hand calcium-binding protein that can identify granule cells in the dentate gyrus of hippocampus. The aim of this study was to determine if secretagogin can be detected in human blood cells. Eight adult males were recruited for blood analysis. Whole blood was separated into plasma, peripheral mononuclear cells and erythrocytes with Ficoll-Paque and probed for secretagogin using reverse-transcription polymerase chain reaction and Western blot. While secretagogin mRNA was detected in both peripheral mononuclear cells and erythrocytes using reverse-transcription polymerase chain reaction, SCGN protein was only detected in erythrocytes. Interestingly, peripheral mononuclear cells secretagogin mRNA expression levels showed significant negative correlation with age. This begets the question on the function of secretagogin in blood cells and if it is correlated to neurodegeneration associated with ageing. This remains our impetus for further research.