Marked changes in red cell membrane proteins in hereditary spherocytosis: a proteomics approach

Hereditary spherocytosis (HS) is the most common red cell membrane defect resulting from protein abnormalities. However, changes in red cell membrane proteins in HS remain under-investigated. We therefore evaluated red cell membrane proteome in non-splenectomized, mild-degree HS patients (n = 9) compared to healthy individuals (n = 5). Proteins derived from the red cell membranes of each subject were resolved in each two-dimensional gel and visualized by Deep Purple fluorescence staining. Spot matching and quantitative intensity analysis revealed 56 differentially expressed protein spots (41 increased and 15 decreased), which were then successfully identified by quadrupole time-of-flight mass spectrometry. Among these, seven isoforms/subunits of spectrin were markedly increased (up to 10.51 folds), whereas two isoforms/subunits of band-3 protein were decreased approximately 50% as compared to normal red cells. However, two isoforms/subunits of protein 4.1 were increased, while another isoform/subunit was decreased. All these significantly altered proteins were subjected to global protein network analysis using Ingenuity Pathways Analysis tool, which revealed three important networks related to HS, including Network I: Cell death, genetic and hematological disorders; Network II: Cell cycle, carbohydrate metabolism and molecular transport; and Network III: Genetic and hematological disorders, cell-to-cell signaling and interactions. These data offer many opportunities and new roadmaps for further functional studies to better understand the biology and pathogenic mechanisms of HS.