Journal: Cell Death Discovery
Article Title: The chaperone GRP94 interacts with the proprotein convertase furin and regulates TGF-beta maturation in human primary M2 macrophages
doi: 10.1038/s41420-025-02866-2
Figure Lengend Snippet: A Furin enzymatic activity analysis in cell lysates of MDA-MB-231 treated or not 24 h with GRP94 inhibitors, PU-WS13 12.5 or 25 µM or GRP94 inhibitor-1 (GRP94inh1) 2.5 or 5 µM ( n = 6). Fluorescence signal (expressed in relative fluorescence units, RFU) due to cleavage of the furin fluorogenic substrate, pERTKR-AMC, in cell lysates was recorded during 30 min. (**** p < 0.0001). Western- blot analysis of ( B ) active TGFβ secretion in supernatants (representative images, n = 7) and ( C ) pro-TGFβ expression in cell lysates (representative images, n = 5) from MDA-MB-231 treated or not 24 h with GRP94 inhibitors, PU-WS13 12.5 or 25 µM or GRP94 inhibitor-1 (GRP94inh1) 2.5 or 5 µM. (* p < 0.05; ** p < 0.01). D GRP94-furin co-immunoprecipitation in MDA-MB-231 cells. GRP94 was immunoprecipitated in MDA-MB-231 cell lysates using an anti-GRP94 antibody (IP:GRP94) or a non-relevant antibody (IgCT). Samples were analyzed by western-blot (representative images, n = 4). E Staining and quantification of proximity ligation assays (Duolink™ PLA) of GRP94 and furin or the negative control Hsp110 in MDA-MB-231 cells treated or not 24 h with GRP94 inhibitor-1 5 µM ( n = 3 experiments). Scale bars = 20 µm. The bar plot represents the mean number of spots for each cell analyzed +/− SEM. (**** p < 0.0001).
Article Snippet: Macrophages were then activated with 20 ng/mL interleukine-4 (IL-4, 130-093-922, Miltenyi) in serum free Opti-MEM medium for 24 h. The GRP94 inhibitor PU-WS13 (HY-18680, MedChemExpress, Monmouth Junction, New Jersey, USA) was added 24 h before activation and during the whole activation period.
Techniques: Activity Assay, Fluorescence, Western Blot, Expressing, Immunoprecipitation, Staining, Ligation, Negative Control