Journal: Science signaling
Article Title: Translocation of TRPV4-PI3Kγ complexes to the plasma membrane drives myofibroblast transdifferentiation
doi: 10.1126/scisignal.aau1533
Figure Lengend Snippet: (A) Domain structure of WT and mutant PI3Kγ constructs consisting of only the non-catalytic N-terminal domain (N-term) or lacking both the N-terminal domain and the ATP binding site in the catalytic domain (N-del). (B) Immunoblotting of His-tagged N-del or N-term forms of PI3Kγ coupled to Ni-NTA beads incubated with lysates of human lung fibroblasts (HLFs). Blots were probed with an antibody recognizing TRPV4, then stripped and reprobed for PI3Kγ. N=3 independent experiments. (C) Direct interaction between immobilized purified 6-His-TRPV4 and purified 6-His-N-term-PI3Kγ was measured by surface plasmon resonance. N=3 independent experiments. (D) Representative fluorescence images showing TRPV4 in PI3Kγ KO murine lung fibroblasts (MLFs) transfected with N-del or N-term PI3Kγ lentivirus (LV) and treated with TGF-β and the corresponding plot profiles of TRPV4 immunofluorescence. White arrows indicate TRPV4 at the plasma membrane; orange lines indicate regions where plot profiles were obtained; white boxes indicate higher magnification insets. Scale bar, 50 μm. (E) Quantification of results from (D). N = 3 independent experiments with at least 30 cells per condition. ***P<0.005 compared with PI3Kγ KO MLF + N-del PI3Kγ LV by Student’s t-test. (F) Western blotting of plasma membrane fractions of PI3Kγ KO MLFs transfected with lentivirus encoding WT PI3Kγ, N-term PI3Kγ, or N-del PI3Kγ, then treated with TGF-β as indicated. Blots were probed for TRPV4, PI3Kγ, and flotillin-1 (loading control). N=3 independent experiments. (G) Representative fluorescence images showing α-SMA in PI3Kγ KO MLFs transfected with control LV (empty vector), WT PI3Kγ LV, N-term PI3Kγ LV or N-del PI3Kγ LV, then stimulated with TGF-β. White boxes indicate areas enlarged in insets. Scale bar, 100 μm. (H) Quantification of results from (G). N = 3 independent experiments with at least 30 cells per condition. ***P<0.005 untreated vs +TGF-β conditions by ANOVA followed by Student-Newman-Keuls multiple comparisons test. All graphs show means ± SEM from N = 3 independent experiments.
Article Snippet: Cell Culture Adult normal human lung fibroblasts (19Lu, catalog # CCl-210) were purchased from American Type Culture Collection (ATCC).
Techniques: Mutagenesis, Construct, Binding Assay, Western Blot, Incubation, Purification, SPR Assay, Fluorescence, Transfection, Immunofluorescence, Clinical Proteomics, Membrane, Control, Plasmid Preparation