Relevance of electrolytic balance in channelopathies.

My PhD project focused on the theme of alterations of electrolytic balance as a consequence of disorders affecting ion channels, which are proteins expressed on the cellular membrane where they physiologically regulate ion concentrations between the intracellular compartment and the extracellular environment. Ion channels disorders are responsible for a group of heterogenic diseases, generally referred as “channelopathies”, that influence the nervous, the cardiovascular, the muscular, the respiratory, the endocrine, the immune or the urinary system. My project dealt with the functional characterization of mutations in genes encoding ion channels identified by collaborating groups in patients affected by different channelopathies. The properties of each mutant channel was compared to the relative wild type form in order to unravel the mechanisms underlying the disease. The mutations studied were a variant in the sodium channel gene SCN4A identified in a patient affected by myotonic dystrophy type 2 (DM2), a mutation in KCNJ2 gene, encoding for the inwardly rectifying potassium channel Kir2.1, identified in a patient affected by a form of autism, GSTM3 CNVs deletion in a cohort of patients affected by Brugada Syndrome and a mutation in KCNT1 gene, encoding for a sodium-dependent potassium channel, identified in a patient affected by Brugada Syndrome. All the single-nucleotide mutations were carried in heterozygosis by the patients. After selecting the most suitable cell line for each subproject, cells were transiently transfected with appropriate vectors to express the WT or the mutant form of the channel. 48 hours after the transfection, patch-clamp in whole cell configuration were performed and specific protocols were applied to characterize ion channels biophysical properties. Data were analyzed through a proper software.

Il mio progetto di dottorato è legato allo studio di mutazioni geniche identificate in pazienti affetti da canalopatie, un gruppo molto eterogeneo di patologie che comprende i disordini a carico dei canali ionici. Poiché i canali ionici sono caratterizzati da un profilo di espressione differente e specifico nelle membrane delle cellule che compongono l’architettura dei vari tessuti, le canalopatie includono malattie del sistema nervoso, cardiovascolare, muscolare, respiratorio, endocrino, urinario e immunitario. La caratterizzazione funzionale dei canali ionici mutati ha lo scopo di comprendere i meccanismi patologici causa delle canalopatie. Durante il dottorato, mi sono occupata di caratterizzare mutazioni in diversi canali ionici associate a patologie differenti, in particolare, ho seguito progetti legati alla caratterizzazione funzionale di una mutazione nel gene SCN4A quale fattore modificante in un fenotipo di distrofia miotonica di tipo 2 (DM2), di una nuova mutazione nel gene KCNJ2 identificata in un paziente affetto da autismo, dello studio del ruolo di GSTM3 come gene modificatore in pazienti affetti da sindrome di Brugada e di una mutazione identificata nel gene KCNT1 in un paziente affetto da sindrome di Brugada.