PLCB3 Loss of Function Reduces Pseudomonas aeruginosa–Dependent IL-8 Release in Cystic Fibrosis

• DOI: 10.1165/rcmb.2017-0267oc
• Publication Date: 2018-04-18T20:49:54Z
• Authors: Alessandro Rimessi; Valentino Bezzerri; Francesca Salvatori; Anna Tamanini; Federica Nigro; Maria Cristina De...; Alessandra Santan...; Paola Prandini; Silvia Munari; Lisa Provezza; Nicolas Garreau d...; Jean Muller; Carla M. P. Ribeiro; Giuseppe Lippi; Roberto Gambari; Paolo Pinton; Giulio Cabrini
• Keywords: 0301 basic medicine; 0303 health sciences; Airway inflammation; Calcium signaling; Cystic fibrosis; IL-8; Phospholipase C-β3; IL-8; Cystic Fibrosis; Interleukin-8; Phospholipase C beta; Bronchi; airway inflammation; calcium signaling; Cell Line; 3. Good health; cystic fibrosis; Mucus; Structure-Activity Relationship; 03 medical and health sciences; phospholipase C-β3; Mutation; Pseudomonas aeruginosa; [SDV.BBM] Life Sciences [q-bio]/Biochemistry, Molecular Biology; Serine; Humans; Computer Simulation; Calcium Signaling

The lungs of patients with cystic fibrosis (CF) are characterized by an exaggerated inflammation driven by secretion of IL-8 from bronchial epithelial cells and worsened by Pseudomonas aeruginosa infection. To identify novel antiinflammatory molecular targets, we previously performed a genetic study of 135 genes of the immune response, which identified the c.2534C>T (p.S845L) variant of phospholipase C-β3 (PLCB3) as being significantly associated with mild progression of pulmonary disease. Silencing PLCB3 revealed that it potentiates the Toll-like receptor's inflammatory signaling cascade originating from CF bronchial epithelial cells. In the present study, we investigated the role of the PLCB3-S845L variant together with two synthetic mutants paradigmatic of impaired catalytic activity or lacking functional activation in CF bronchial epithelial cells. In experiments in which cells were exposed to P. aeruginosa, the supernatant of mucopurulent material from the airways of patients with CF or different agonists revealed that PLCB3-S845L has defects of 1) agonist-induced Ca2+ release from endoplasmic reticulum and rise of Ca2+ concentration, 2) activation of conventional protein kinase C isoform β, and 3) induction of IL-8 release. These results, besides identifying S845L as a loss-of-function variant, strengthen the importance of targeting PLCB3 to mitigate the CF inflammatory response in bronchial epithelial cells without blunting the immune response.