inhibitor ml141  (Merck & Co)

Journal: Frontiers in Immunology

Article Title: The Rho GTPase signaling pathway modulates Moraxella catarrhalis invasion into human respiratory epithelial cells by regulating actin polymerization

doi: 10.3389/fimmu.2026.1730864

Figure Lengend Snippet: CDC42 -/- A549, Rac1 -/- A549, ArpC2 -/- A549 and ArpC4 -/- A549 cell lines.

Article Snippet: Actin-related protein 2/3 complex (Arp2/3) inhibitor CK-636 (CK-0944636, Cat. No. IC3650, Beijing Solarbio Science &Technology Co., Ltd), CDC42 GTPase inhibitor ML 141 (ab145603, Cat. No. 10155-1-AP, Proteintech Group, Inc. Chicago, USA), actin polymerization inhibitor: Latrunculin A (Cat. No. HY-16929, MedChem Express LLC), Rho GTPase inhibitor: Simvastatin (Cat. No. IS0170, Beijing Solarbio Science &Technology Co., Ltd.), Rac1/CDC42 activator: CN02-B (Cat. No. CN02-B, Cytoskeleton, Inc.).

Techniques:

Journal: Frontiers in Immunology

Article Title: The Rho GTPase signaling pathway modulates Moraxella catarrhalis invasion into human respiratory epithelial cells by regulating actin polymerization

doi: 10.3389/fimmu.2026.1730864

Figure Lengend Snippet: Critical role of CDC42 in the Rho GTPase signaling pathway during M. catarrhalis invasion into A549 cells. (A) Comparison of invasion counts of M. catarrhalis strains 73-OR and ATCC 25238 into WT A549 cells vs. CDC42 -/- A549 cells. Data are presented as mean ± standard error (SE) from three independent biological replicates (n=3). Statistical significance was determined using an unpaired Student’s t-test. To accurately assess the magnitude of the impact given the limited sample size, effect sizes (Cohen’s d) and mean differences are reported alongside P-values. (B) Transmission electron micrographs (TEM) of 73-OR and ATCC 25238 invading WT A549 cells and CDC42 -/- A549 cells. (C) TEM quantification of M. catarrhalis invasion into wild-type and CDC42 -/- A549 cells. Invasion counts for M. catarrhalis strains 73-OR and ATCC 25238 were quantified by counting the number of bacteria internalized within wild-type (WT) and CDC42 -/- A549 cells via Transmission Electron Microscopy (TEM). Data represent the mean ± standard error(SE) from three independent biological replicates (n =3). Within each biological replicate, three random microscopic fields at the same magnification were selected and counted. Statistical significance between groups was determined using the non-parametric Mann-Whitney U test. Both 73-OR and ATCC 25238 strains showed a significant reduction in invasion into CDC42 -/- A549 cells compared to WT cells. (D) Quantitative comparison of F-actin/G-actin ratios in WT A549 cells and CDC42 -/- A549 cells post-infection with M. catarrhalis strains 73-OR and ATCC 25238. Data are presented as the mean ± standard error(SE) from three independent biological replicates (n=3). Statistical comparison between groups was performed using an unpaired Student’s t-test. (E) Immunofluorescence analysis of F-actin polymerization in A549 cells post-infection. Wild-type (WT) and CDC42 -/- A549 cells were challenged with M. catarrhalis strains 73-OR and ATCC 25238, fixed, and stained. Blue: nuclei; Green: F-actin. (F) Analysis of microfilament expression levels in WT A549 cells vs. CDC42 -/- A549 cells following infection with 73-OR and ATCC 25238. Data are presented as the mean ± standard error(SE) from three independent biological replicates (n=3). Statistical comparison between groups was performed using an unpaired Student’s t-test.

Article Snippet: Actin-related protein 2/3 complex (Arp2/3) inhibitor CK-636 (CK-0944636, Cat. No. IC3650, Beijing Solarbio Science &Technology Co., Ltd), CDC42 GTPase inhibitor ML 141 (ab145603, Cat. No. 10155-1-AP, Proteintech Group, Inc. Chicago, USA), actin polymerization inhibitor: Latrunculin A (Cat. No. HY-16929, MedChem Express LLC), Rho GTPase inhibitor: Simvastatin (Cat. No. IS0170, Beijing Solarbio Science &Technology Co., Ltd.), Rac1/CDC42 activator: CN02-B (Cat. No. CN02-B, Cytoskeleton, Inc.).

Techniques: Comparison, Transmission Assay, Bacteria, Electron Microscopy, MANN-WHITNEY, Infection, Immunofluorescence, Staining, Expressing

Journal: NPJ Parkinson's Disease

Article Title: Microglial low-affinity FcγR mediates the phagocytic elimination of dopaminergic neurons in Parkinson’s disease degeneration

doi: 10.1038/s41531-025-01249-9

Figure Lengend Snippet: A CD16/32 accumulates at the leading front of motile microglia. Top panel shows maximum intensity projection of a BV2 cell marked with CD16/32 and DAPI. Leading lamellas (left pole) and the uropod (opposite pole) indicate its direction. Bottom panel shows a 0.5 μm optical plane represented in a scale of 16 colors. Scale on the bottom (white represents the highest value and black the lowest). Leading front lamellas (1) and uropod (2) are indicated (Scale bar: 10 μm). B Illustration of a characteristic motile microglial cell showing essential cytoskeletal elements (Modified from Roig-Martinez et al.) . C Plot of relative fluorescence of motile microglia measured (white broken line) from the image on the left. Note the higher fluorescence at the leading front (1) and a smaller peak at the uropod (2). D BV2 microglia in kinetic shape showing accumulation of Cdc42 at the leading edge (asterisk). E Relative fluorescence of BV2 microglia from panel D indicates the Cdc42 increase at the cell frontal lamella (asterisk) (Scale bar: 10 μm). F Representative image of a BV2 microglial cell expressing a high density of Cdc42 (red) in an F-actin-rich protrusion. The nucleus was counterstained with DAPI (blue). (Scale bar: 3 μm). G Plot profile of relative fluorescence displays high expression of Cdc42 corresponding with high fluorescence of F-actin at the protruding edge (2) compared with the nucleus (1). H Clusters of Cdc42 can be seen at the microglial lamelipodia. Detailed of clusters are shown in higher magnification (yellow arrowheads) from white inset (Scale bar: 10 μm). I Cdc42 is spread as filaments towards to F-actin-rich microglial cell border. Higer magnification from white inset shows detail of the filaments (white arrowheads) (Scale bar: 10 μm). J Higher resolution images from orange inset show that Cdc42 accumulates at the inner part of the F-actin cellular processes (Z confocal steps +3 μm and +4 μm from the culture plate bottom are shown) (Scale bar: 5 μm). K Confocal image of microglial cell establishing a phagocytic cup around a dopaminergic cell (1). The PC12 DA cell is marked with dopaminergic neuronal marker, TH (green), and the microglial cell is stained by F-actin (magenta). (2) Diagram of the engulfing process depicted in 1. (3) Image of F-actin fluorescence intensity of the engulfing microglia seen in 1. Note the higher intensity is displayed at the borders of the phagocytic cup. (4) higher magnification of the phagocytic cup to visualize the characteristic accumulations of F-actin (Scale bar: 10 μm). (5) 3D reconstruction of the phagocytic event displaying the microglia arranging the F-actin-rich phagocytic cup around a dopaminergic cell (yellow arrowhead). L Increasing concentrations of ML141 were safe for BV2 cell viability. MTT cell viability assay for BV2 microglial cells submitted to increasing concentrations of ML141 was performed to test their safety: 500 μg of H 2 O 2 resulted in approximately 50% decrease of the cell viability. But no significant decrease was appreciated after the administration of ML141 or vehicle (*** p ˂0.001 H 2 O 2 significant against every other treatment). M Quantification of the number of PC12 DA cells at 60 min. of interaction with BV2 microglia. BV2 were treated either before or after activation with Cdc42 inhibitor ML141. The proinflammatory-mediated elimination of DA cells was prevented when BV2 cells were incubated with ML141. (Pre-activation inhibition ** p ˂0.01 IFN-γ + LPS vs. ML141/IFN-γ + LPS and ML141. Post-activation inhibition $$$ p ˂0.001 IFN-γ + LPS vs. every condition and **** p ˂0.0001 control vs. IFN-γ + LPS).

Article Snippet: To analyze how the inhibition of the protein Cdc42 affects the preservation of dopaminergic cells, the inhibitor ML141 (Cdc42/Rac1 GTPase Inhibitor, MERCK, Calbiochem, San Diego, CA, USA) was used in BV2/PC12 co-cultures.

Techniques: Modification, Fluorescence, Expressing, Marker, Staining, Viability Assay, Activation Assay, Incubation, Inhibition, Control

Journal: NPJ Parkinson's Disease

Article Title: Microglial low-affinity FcγR mediates the phagocytic elimination of dopaminergic neurons in Parkinson’s disease degeneration

doi: 10.1038/s41531-025-01249-9

Figure Lengend Snippet: A Diagram of the procedure used for the CD16/32 passive immunotherapy. Neuropathological histology was performed in the SNpc (red square). B Representative confocal images showing the SNpc labeled with TH and counterstained with DAPI. Depletion of DA neurons can be appreciated in MPTP-treated animals. However, a protective effect can be seen in mice treated with CD16/32 neutralizing monoclonal antibodies (αCD16/32) (Scale bar: 30 μm). C Quantification of the DA neurons in the SNpc demonstrating a significant decrease in the MPTP group which is prevented by the administration of CD16/32 (*** p ˂0.001 MPTP vs. every treatment except MPTP + Isotype, ### p˂0.001 MPTP + Isotype vs. every treatment except MPTP). D 3D reconstruction of representative microglial cells expressing Iba-1 in different treatments of the experiment (Scale bar: 10 µm). E Quantification of the area of Iba-1 in the SNpc, indicating variation of microglial size when the animals were intoxicated with MPTP. F CD16/32 immunostaining reveals increased immunoreactivity in MPTP-treated animals (Scale bar: 20 μm). G Quantification of CD16/32 cell number shows increased levels in MPTP-treated animals. H Diagram of the procedure used for Cdc42 inhibition. I Representative confocal images of histological analysis. Upper panel: Representative images of TH positive neurons of the SNpc in every treatment (Scale bar: 30 µm). Lower panel: 3D reconstructions illustrating morphology and changes of size in microglial cells expressing Iba-1 (Scale bar: 10 µm). J Quantification of TH positive neurons indicating a significant decrease in the MPTP group and prevention by the previous administration of Cdc42 inhibitor ML141 (** p < 0.01 with respect to saline). K Quantification of the Iba-1 expressing area, which represents changes in microglial size. Microglial activation is present in the MPTP group evidenced by the increased area of Iba-1, which is decreased in the animals intoxicated with MPTP but previously treated with ML141 (*** p < 0.001 with respect to controls, $$ p < 0.01 with respect to ML141). L CD16/32 immunostaining reveals immunoreactivity in the MPTP group, providing a strong inhibition in MPTP-ML141 group (Scale bar: 30 μm). M Quantification of CD16/32+ microglia show a significant increase in the MPTP-treated group (** p < 0.01 compared to ML141 + MPTP).

Article Snippet: To analyze how the inhibition of the protein Cdc42 affects the preservation of dopaminergic cells, the inhibitor ML141 (Cdc42/Rac1 GTPase Inhibitor, MERCK, Calbiochem, San Diego, CA, USA) was used in BV2/PC12 co-cultures.

Techniques: Labeling, Bioprocessing, Expressing, Immunostaining, Inhibition, Saline, Activation Assay

Journal: bioRxiv

Article Title: Vav2 is a master regulator of repair against bacterial pore-forming toxins

doi: 10.1101/2025.07.31.668026

Figure Lengend Snippet: HeLa cells were serum-starved for 30 min, treated with DMSO or 5, 10, or 20 μM (A) Rac inhibitor EHop016, (B) cdc42 inhibitor ML141, (C) Rho inhibitor Y16, (D) ROCK inhibitor Y27632, (E) 20 μM Y16, Y27632, or EHop016 or (F) 20 μM ML141, EHop016, Y16, or all three, and challenged with 31-2000 HU/mL SLO or PFO for 30 min at 37°C. Propidium iodide (PI) uptake was analyzed by flow cytometry. The LC 50 was calculated as described in the methods. Graphs show independent experiments and the mean ±S.E.M, n=5 (A, B, D (SLO), B, C, (PFO)), n=4 (A, D, E, (PFO), D, E, F (SLO)), n=6 (C, SLO), or n=3 (F, PFO). *p<0.05, **p<0.01, ***p<0.001, ****p<0.0001 denote statistical significance using repeated-measures ANOVA between groups with Tukey post-test.

Article Snippet: Rac inhibitor EHop016 (Cat# S7319), cdc42 inhibitor ML141(Cat# S7686), and FAK/Pyk2b inhibitor PF431396 (Cat# S7644) were from Selleckchem (Houston, TX, USA).

Techniques: Flow Cytometry