Expression Profiles of Phosphatidylinositol Phosphate Kinase Genes During Normal Human in Vitro Erythropoiesis.

Phosphatidylinositol phosphate kinases (PIPKs) are enzymes that participate in diverse intracellular signaling pathways. They are classified into 3 functionally distinct subfamilies - PIPKI (alpha, beta, gamma), PIPKII (alpha, beta, gamma), and PIPKIII - located in various subcellular compartments. Recently, the PIPKII alpha and beta-globin genes were found to be overexpressed in reticulocytes from 2 siblings with hemoglobin H disease, suggesting a possible relationship between PIPKII alpha and the production of globins. The main aim of this study was to determine the expression profiles of PIPK genes in healthy individuals during in vitro erythropoiesis using quantitative real-time polymerase chain reaction and to compare these profiles with profiles of globin genes. Our results showed that expression of all PIPKs increases as the cells differentiate, coinciding with the expression profiles of globins. Analysis of the effects of globins on PIPK genes revealed that they varied significantly between the globins, the most noticeable being the effect of alpha-globin on PIPKII alpha (P < 0.0001) and gamma-globin on PIPKII gamma (P < 0.0001). The relationship between the expression of PIPKs and globin genes was statistically significant, particularly between PIPKII alpha and alpha-globin (P = 0.0002) and PIPKII gamma and beta-globin (P < 0.0001). Linear correlation analysis revealed a strong relationship between PIPKII alpha and alpha-globin genes. This study is the first to establish the expression profiles of PIPK genes during in vitro erythropoiesis in healthy individuals and suggests a parallel between the expression of PIPK and globin genes, reinforcing the hypothesis that they may be related.