Journal: PLOS Biology
Article Title: RNA-binding protein IMP1/ZBP1 directs local translation in microglial processes to regulate motility and phagocytosis during inflammation
doi: 10.1371/journal.pbio.3003463
Figure Lengend Snippet: (A) IMP1/ZBP1 downregulation upon microglia transfection with an Imp1 -targeting siRNA. Representative western blot showing IMP1/ZBP1 and total protein levels following transfection with a control (ctrl KD) and an Imp1 -targeting siRNA ( Imp1 KD) (A i ) . The bar graph summarizes the quantification of western blots obtained from 3 independent cultures ( n = 3). Two-tailed t test; n.s, not significant (A ii ) . (B) Imp1 knockdown (KD) alters Actb mRNA localization toward the periphery of microglia. Linescans show the mean distribution ±SEM of the Actb FISH signal from the nucleus to the PeMPs in 38–48 individual cells per condition (B i ) . The bar graph represents the relative Actb intensity (compared to control-transfected cells exposed to PBS) in PeMPs from microglia treated with PBS or LPS and transfected with a control (ctrl KD) or an Imp1 -targeting (Imp1 KD) siRNA in 5 independent experiments ( n = 5). One-way ANOVA followed by Holm–Šídák’s multiple comparison test. * p < 0.05; ** p < 0.01; n.s, not significant (B ii ) . (C) Relative distribution of Actb foci in binarized images. (1) and (2) indicate the PeMPs and the perinuclear regions, respectively, (C i ) represented in insets (C ii ) . Scale bars, 20 µm (C i ) and 10 µm (C ii ). The relative frequency distribution of Actb foci in the periphery and the soma of microglia transfected with a control (ctrl KD) siRNA or an Imp1 siRNA ( Imp1 KD) and exposed to PBS or LPS for 30 min in 5 independent experiments ( n = 5) is plotted in (C iii ) . Two-way ANOVA followed by Holm–Šídák’s multiple comparison test. * p < 0.05; ** p < 0.01; n.s, not significant. (D) Imp1 KD blocks LPS-induced localized translation in microglia. Local β-actin synthesis was assessed with a 2-min puromycin pulse in PBS- and LPS-treated cells and transfected with control (ctrl KD) or Imp1 siRNAs ( Imp1 KD), followed by PLA with antibodies against puromycin and β-actin. As a negative control, cells were preincubated with the protein synthesis inhibitor anisomycin. Representative images of microglial PLA-labeled lamellae and stained with phalloidin are shown. Scale bar, 10 µm (insets, 5µm) (D i ) . The box and whisker graph represents the average of PLA puncta within lamellae in phalloidin-stained microglia cultured in 6 independent experiments ( n = 6) analyzed by two-way ANOVA followed by Holm–Šídák’s multiple comparison test. * p < 0.05; n.s, not significant (D ii ) . The data underlying this Figure can be found in .
Article Snippet: Cells were incubated for 20 min at room temperature with 500 nM SYTO RNA Select green fluorescent dye in PBS (Invitrogen).
Techniques: Transfection, Western Blot, Control, Two Tailed Test, Knockdown, Comparison, Negative Control, Labeling, Staining, Whisker Assay, Cell Culture