Journal: bioRxiv
Article Title: Investigation of CD36 interactome provides insights into multimolecular complexes necessary for anti-angiogenic signalling
doi: 10.1101/2025.07.15.664851
Figure Lengend Snippet: ( A ) Representative three-color TIRFm images of CD36 (yellow), active ITGB1 (Cyan) and CD9 (Magenta). The coordinates of molecules present in each channel are determined using a point source detection algorithm based on u-track (see details in material and methods). After object detection, analysis was performed with a colocalization radius of 2 pixels (180 nm). Triple colocalization events, where CD36, active ITGB1 and CD9 objects were all found within a 2 pixels radius of one another are denoted in white. Two-color colocalization events between CD36-active ITGB1, CD36-CD9, and active ITGB1-CD9 are denoted by red, green and yellow circles respectively. Further statistical analysis from the conditional analysis package extracts the colocalization extent between 2 molecules and the effect of a third one on their association. ( B ) Two-molecular colocalization measures between CD36 and active ITGB1, CD9 and TfR (as a negative control). Extent of the colocalization of HT-CD36 (labeled with HT-JFX-549) with CD36 (using mouse anti-CD36), or with active ITGB1, CD9 and TfR are shown as boxplots with the experimental data in blue and the nullTR (where (T) positions are replaced with point in a grid) in black. Statistical analysis between experimental data and nullTR was calculated using non-parametric Kruskal-Wallis test with significant difference indicated by p < 0.05. Comparison between groups was measured using non-parametric Kruskal-Wallis test followed by a Dunn’s post-hoc test to determine pairwise significance values, indicated for the relevant comparisons. Results are from 3 replicates and a minimum of 35 cells imaged. ( C ) Conditional colocalization analysis measuring the effect of CD9 on the colocalization of CD36 with ITGB1. The analysis provides a set of conditional colocalization extent measures to establish in a robust statistical fashion the relationship between 3 molecules. Here, the effect of CD36 colocalization with CD9 on CD36’s colocalization with ITGB1 and the effect of ITGB1’s colocalization with CD9 on CD36’s colocalization with ITGB1 are presented. Triple colocalization values were compared to the coincidental colocalization measures (nullTR in black and RandC in green) and overall colocalization measure p(CD36wITGB1) to determine CD9’s colocalization effect on CD36-active ITGB1 colocalization. ( D ) Summary of conditional colocalization measurements from panel C indicating the effect of CD9 on the colocalization between CD36 and ITGB1. Median colocalization extent for each measurement is indicated within each circle. P-values determination for overall colocalizations was done using non-parametric Kruskal-Wallis test between experimental data and nullTR with -log 10 (p-value) above 1.3 indicative of p<0.05. For three-molecular conditional colocalization measurements, the least significant p-value among three comparisons (overall colocalization, nullTR and RandC) was expressed as a -log 10 (p-value). Thresholds for three molecular colocalization significance were calculated with Dunn-Sidak correction reducing the significance threshold to 1.7. ( E ) Similar summary of conditional colocalization determining the effect of active ITGB1 on the colocalization of CD36 with CD9. ( F ) Negative control conditional colocalization values measuring the effect of active ITGB1 on the colocalization of CD36 with TfR. Results are from at least 3 experiments and > 40 cells imaged per condition.
Article Snippet: Plasmids expressing scrambled, ITGB1, or CD9 shRNA were obtained from VectorBuilder (VectorBuilder Inc., IL, USA) and consisted of a pLV vector, containing an hygromycin resistance cassette, and the shRNA under the control of a constitutively active U6 promoter.
Techniques: Negative Control, Labeling, Comparison