arl67156  (Tocris)

Journal: Nature Communications

Article Title: Microglia regulate motor neuron plasticity via reciprocal fractalkine and adenosine signaling

doi: 10.1038/s41467-024-54619-x

Figure Lengend Snippet: A Schematic of experimental setup with intrathecal drug delivery and placement of adenosine (ADO) and inosine (INO) micro-biosensors. B Intrathecal fractalkine (Fkn; 100 ng; 12 μL) delivery evoked a slow increase in extracellular adenosine concentration over 30 min ( n = 3 independent recordings from 3 rats; Linear Regression ANOVA: * p < 0.001; r = 0.993, r 2 = 0.986, Adjusted r 2 = 0.986). Concurrently, phrenic nerve activity was recorded in urethane anesthetized rats maintained at baseline conditions during and after intrathecal Fkn injection (90 min post-delivery). Ventilator volumes were set for each rat based on body mass (0.007 ml * body mass, g; 72–74 breaths per minute). Inspired CO 2 or ventilator frequency was adjusted to maintain end-tidal PCO 2 between 38 and 41 mmHg. Blood gas measurements were taken 2–3 times during the initial baseline, and at 30, 60, and 90-min post-drug (Supplementary Table ). C Schematic of inter-cellular signaling highlighting where receptors/enzymes were blocked/inhibited in D – H . Representative compressed neurograms of integrated phrenic nerve activity are shown for rats that received ( D ) vehicle (VEH; time controls; n = 7 rats, each rat with 1 independent recording), E VEH + Fkn ( n = 6 rats, each rat with 1 independent recording), ( F ) CX3CR1 inhibitor, AZD8797 + Fkn ( n = 7 rats, each with 1 independent recording), G ATPase inhibitor, ARL67156 + Fkn ( n = 7 rats, each with 1 independent recording), and H A2A Receptor inhibitor, MSX-3 + Fkn ( n = 7 rats, each with 1 independent recording). I Phrenic burst amplitude (percent change from baseline; % baseline) was significantly increased 90 min post-Fkn administration (VEH + Fkn); however, CX3CR1, ATPase and A2A receptor inhibition (schematized in C ) attenuated or prevented phrenic motor facilitation (F(4,29) = 21.378, p < 0.001; one-way ANOVA). * p < 0.001, significant differences vs all groups; Tukey post-hoc Test. Bars show mean ± SEM. Source data are provided as a Source Data file. Figures created in BioRender. Marciante, A. (2024) https://BioRender.com/e55f542 .

Article Snippet: Drugs used include MSX-3 (A2A receptor antagonist; #M3568; Millipore Sigma), Recombinant Rat CX3CL1 protein (#537-FT-025; FisherSci), AZD8797 (CX3CR1 antagonist; #2255; Axon Medchem), JMS-17-2 (selective CX3CR1 antagonist; #HY-123918; MedChemExpress) and ARL67156 (selective ecto-ATPase inhibitor; #128310; FisherSci).

Techniques: Concentration Assay, Activity Assay, Injection, Inhibition

Journal: bioRxiv

Article Title: Microglia regulate motor neuron plasticity via reciprocal fractalkine/adenosine signaling

doi: 10.1101/2024.05.07.592939

Figure Lengend Snippet: ( A ): Schematic of experimental setup with intrathecal drug delivery and placement of adenosine (ADO) and inosine (INO) micro-biosensors. ( B ) Intrathecal fractalkine (Fkn; 100 ng; 12 μL) delivery evoked a slow increase in extracellular adenosine concentration over 30 min (n = 3 independent recordings; Linear Regression, p < 0.001; r = 0.993, r 2 = 0.985, Adjusted r 2 = 0.985). Concurrently, phrenic nerve activity was recorded in urethane anesthetized rats maintained at baseline conditions during and after intrathecal Fkn injection (90 min post-delivery). Ventilator volumes were set for each rat based on body mass (0.007 ml * body weight, g; 72-74 breaths per minute). Inspired CO2 or ventilator frequency were adjusted to maintain end-tidal PCO 2 between 38 and 41 mmHg. Blood gas measurements were taken 2-3 times during the initial baseline, and at 30, 60, and 90-min post-drug ( Supplementary Table 1 ). ( C ) Schematic of inter-cellular signaling highlighting where receptors/enzymes were blocked/inhibited in D - H. Representative compressed neurograms of integrated phrenic nerve activity are shown for rats that received ( D ) vehicle (VEH; time controls), ( E ) VEH + Fkn, ( F ) CX3CR1 inhibitor, AZD8797 + Fkn, ( G ) ATPase inhibitor, ARL67156 + Fkn, and ( H ) A2A Receptor inhibitor, MSX-3 + Fkn. ( I ) Phrenic burst amplitude (percent change from baseline; % baseline) was significantly increased 90 min post-Fkn administration (VEH + Fkn); however, CX3CR1, ATPase and A2A receptor inhibition (schematized in C ) attenuated or prevented phrenic motor facilitation (n=6-7 recordings per group; F(4,29) = 21.378, p < 0.001; one-way ANOVA). ****p < 0.001, significant differences vs all groups; Tukey post-hoc Test. Bars show mean ± SEM.

Article Snippet: Drugs used include MSX-3 (A 2A receptor antagonist; #M3568; Millipore Sigma), Recombinant Rat CX3CL1 protein (#537-FT-025; FisherSci), AZD8797 (CX3CR1 antagonist; #2255; Axon Medchem), and ARL67156 (selective ecto-ATPase inhibitor; #128310; FisherSci).

Techniques: Concentration Assay, Activity Assay, Injection, Inhibition