Proteomic analysis reveals aberrant expression of CALR and HSPA5 in thyroid tissues of Graves' disease

To explore the proteomic changes in thyroid tissue from GD patients and find new biomarkers for the prevention, diagnosis as well as the treatment of GD. Group1 included five thyroid specimens of GD cases and 5 normal thyroid tissue samples which were removed surgically and collected. The proteins were extracted from these thyroid tissues and then the differentially expressed protein spots were identified by MALDI-TOF-MS. The interested proteins were further validated in more specimens (group2: 11 pathological thyroid specimens and 7 normal thyroid tissue samples). A total of 34 differentially expressed proteins were observed, and the majority of these proteins were involved in endoplasmic reticulum stress (ER-stress), oxidative stress, energy metabolism, cytoskeleton and movement. The overexpression of calreticulin(CALR) and heat shock 70kDa protein 5(HSPA5) was further validated. Alltogether, abundant new candidate molecules, especially proteins related to ER-stress, were found to be involved in the pathogenesis of GD. •CALR and HSPA5 are overexpressed in GD.•ER-stress may be involved in the pathogenesis of GD.•2-DE combined with MALDI-TOF-MS may be a useful way to find new protein biomarkers.