TY - JOUR
T1 - Calpain Inhibition Promotes the Rescue of F508del-CFTR in PBMC from Cystic Fibrosis Patients
AU - Averna, Monica
AU - Pedrazzi, Marco
AU - Minicucci, Laura
AU - De Tullio, Roberta
AU - Cresta, Federico
AU - Salamino, Franca
AU - Pontremoli, Sandro
AU - Melloni, Edon
PY - 2013/6/13
Y1 - 2013/6/13
N2 - A basal calpain activity promotes the limited proteolysis of wild type (WT) cystic fibrosis conductance regulator (CFTR), inducing the internalization of the split channel. This process contributes to the regulation in the level of the active CFTR at the plasma membranes. In peripheral blood mononuclear cells (PBMC) from 16 healthy donors, the inhibition of calpain activity induces a 3-fold increase in the amount of active WT CFTR at the plasma membranes. Instead, in PBMC from cystic fibrosis (CF) patients, calpain activity is expressed at aberrant levels causing the massive removal of F508del-CFTR from the cell surface. In these patients, the inhibition of such abnormal proteolysis rescues physiological amounts of active mutated CFTR in 90% of the patients (25 over 28). The recovery of functional F508del-CFTR at the physiological location, in cells treated with a synthetic calpain inhibitor, indicates that F508del-CFTR folding, maturation, and trafficking operate in CF-PBMC at significant rate. Thus, an increase in the basal calpain activity seems primarily involved in the CFTR defect observed in various CF cells. Furthermore, in CF-PBMC the recovery of the scaffolding protein Na+/H+ exchanger regulatory factor 1 (NHERF-1), occurring following inhibition of the aberrant calpain activity, can contribute to rescue CFTR-functional clusters.
AB - A basal calpain activity promotes the limited proteolysis of wild type (WT) cystic fibrosis conductance regulator (CFTR), inducing the internalization of the split channel. This process contributes to the regulation in the level of the active CFTR at the plasma membranes. In peripheral blood mononuclear cells (PBMC) from 16 healthy donors, the inhibition of calpain activity induces a 3-fold increase in the amount of active WT CFTR at the plasma membranes. Instead, in PBMC from cystic fibrosis (CF) patients, calpain activity is expressed at aberrant levels causing the massive removal of F508del-CFTR from the cell surface. In these patients, the inhibition of such abnormal proteolysis rescues physiological amounts of active mutated CFTR in 90% of the patients (25 over 28). The recovery of functional F508del-CFTR at the physiological location, in cells treated with a synthetic calpain inhibitor, indicates that F508del-CFTR folding, maturation, and trafficking operate in CF-PBMC at significant rate. Thus, an increase in the basal calpain activity seems primarily involved in the CFTR defect observed in various CF cells. Furthermore, in CF-PBMC the recovery of the scaffolding protein Na+/H+ exchanger regulatory factor 1 (NHERF-1), occurring following inhibition of the aberrant calpain activity, can contribute to rescue CFTR-functional clusters.
UR - http://www.scopus.com/inward/record.url?scp=84878998729&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84878998729&partnerID=8YFLogxK
U2 - 10.1371/journal.pone.0066089
DO - 10.1371/journal.pone.0066089
M3 - Article
C2 - 23785472
AN - SCOPUS:84878998729
VL - 8
JO - PLoS One
JF - PLoS One
SN - 1932-6203
IS - 6
M1 - e66089
ER -