title: PI3K p110γ overexpression in idiopathic pulmonary fibrosis lung tissue and fibroblast cells: in vitro effects of its inhibition.
abstract: Idiopathic pulmonary fibrosis (IPF) is a progressive fibroproliferative disease whose molecular pathogenesis remains unclear. In a recent paper, we demonstrated a key role for the PI3K pathway in both proliferation and differentiation into myofibroblasts of normal human lung fibroblasts treated with TGF-β. In this research, we assessed the expression of class I PI3K p110 isoforms in IPF lung tissue as well as in tissue-derived fibroblast cell lines. Moreover, we investigated the in vitro effects of the selective inhibition of p110 isoforms on IPF fibroblast proliferation and fibrogenic activity. IHC was performed on normal and IPF lung tissue. Expression levels of PI3K p110 isoforms were evaluated by western blot and flow cytometry analysis. Fibroblast cell lines were established from both normal and IPF tissue and the effects of selective pharmacological inhibition as well as specific gene silencing by small interfering RNAs were studied in vitro. No significant differences between normal and IPF tissue/tissue-derived fibroblasts were observed for the expression of PI3K p110 α, β and δ isoforms whereas p110γ was more greatly expressed in both IPF lung homogenates and ex vivo fibroblast cell lines. Myofibroblasts and bronchiolar basal cells in IPF lungs exhibited strong immunoreactivity for p110γ. Positive staining for the markers of proliferation proliferating cell nuclear antigen and cyclin D1 was also shown in cells of fibrolastic foci. Furthermore, both p110γ pharmacological inhibition and gene silencing were able to significantly inhibit proliferation rate as well as α-SMA expression in IPF fibroblasts. Our data suggest that PI3K p110γ isoform may have an important role in the etio-pathology of IPF and can be a specific pharmacological target.
authors: Department of Clinical and Molecular Biomedicine, University of Catania, Catania 95123, Italy. econte@unict.it
authors: Enrico
authors: E
authors: Conte
authors: Elisa
authors: E
authors: Gili
authors: Mary
authors: M
authors: Fruciano
authors: Martina
authors: M
authors: Korfei
authors: Evelina
authors: E
authors: Fagone
authors: Maria
authors: M
authors: Iemmolo
authors: Debora
authors: D
authors: Lo Furno
authors: Rosario
authors: R
authors: Giuffrida
authors: Nunzio
authors: N
authors: Crimi
authors: Andreas
authors: A
authors: Guenther
authors: Carlo
authors: C
authors: Vancheri
mesh_terms: D000328:Adult; D048708:Cell Growth Processes / Q000502:physiology; D002478:Cells, Cultured; D058534:Class I Phosphatidylinositol 3-Kinases / Q000037:antagonists & inhibitors* / Q000096:biosynthesis* / Q000235:genetics / Q000378:metabolism; D003094:Collagen / Q000737:chemistry; D019938:Cyclin D1 / Q000378:metabolism; D005260:Female; D005347:Fibroblasts / Q000166:cytology / Q000201:enzymology*; D020868:Gene Silencing; D006801:Humans; D054990:Idiopathic Pulmonary Fibrosis / Q000201:enzymology* / Q000378:metabolism / Q000473:pathology; D007150:Immunohistochemistry; D008168:Lung / Q000737:chemistry / Q000166:cytology; D008297:Male; D008875:Middle Aged; D058628:Myofibroblasts / Q000166:cytology / Q000201:enzymology; D018809:Proliferating Cell Nuclear Antigen / Q000378:metabolism; D020033:Protein Isoforms; D047428:Protein Kinase Inhibitors / Q000494:pharmacology; D034741:RNA, Small Interfering / Q000008:administration & dosage / Q000235:genetics; D015854:Up-Regulation
chemical_list: C530104:CCND1 protein, human; D018809:Proliferating Cell Nuclear Antigen; D020033:Protein Isoforms; D047428:Protein Kinase Inhibitors; D034741:RNA, Small Interfering; D019938:Cyclin D1; D003094:Collagen; D058534:Class I Phosphatidylinositol 3-Kinases