Novel charged sodium and calcium channel inhibitor active against neurogenic inflammation
- Boston Children's Hospital, United States
- Harvard Medical School, United States
- Université de Montréal, Canada
- Renaissance School of Medicine at Stony Brook University, United States
- Sage Partner International, United States
Figures
Figure 1
State dependent inhibition of Cav2.2 channels by the neutral compound NNCB-2.
(A) Time course of inhibition of Cav2.2 current by external NNCB-2 applied at concentrations from 3 to 100 µM. Current carried by 5 mM Ba2+ was evoked by 50-millisecond steps from −70 to +10 mV delivered every 3 s. Data points show mean SEM (n = 4). Inset: Structure of NNCB-2 (3-Cyclopentylmethylsulfanyl-2-(3,3-dimethyl-butylamino)-N-(4-methoxy-benzyl)-propionamide). (B) Inhibition by 10 µM NNCB-2 of Cav2.2 current with current evoked from a holding potential of −70 mV (top) or −100 mV (bottom). (C) Test for reversibility of NNCB-2 following exposure for 1 min, using 50 ms test pulses to +10 mV from a holding potential of either −70 mV (n = 3) or −100 mV (n = 7). Source data 1.
Figure 2
State dependent inhibition of Cav2.2 channels by the charged compound CNCB-2.
(A) Time course of inhibition of Cav2.2 current by external CNCB-2 applied at concentrations from 10 to 300 µM. Current carried by 5 mM Ba2+ current was evoked by 50-millisecond steps from −70 to +10 mV delivered every 3 s. Data points show mean ± SEM (n = 4). Inset: Structure of CNCB-2 ([2-Cyclopentylmethylsulfanyl-1-(4-methoxy-benzylcarbamoyl)-ethyl]−(3,3-dimethyl-butyl)-dimethyl-ammonium, chloride salt). (B) Inhibition by 30 µM CNCB-2 of Cav2.2 current with current evoked from a holding potential of −70 mV (top) or −100 mV (bottom). (C) Minimal reversal of CNCB-2 inhibition by washing following exposure for 1 min, using 50 ms test pulses to +10 mV from a holding potential of either −70 mV (n = 9) or −100 mV (n = 7). Source data can be found in Source data 1.
Figure 3
Test of whether Cav2.2 inhibition by NNCB-2 and CNCB-2 requires channel opening and comparison of internal and external application of CNCB-2 .
(A) Calcium channel inhibition by NNCB-2 or CNCB-2 does not require channel opening. Ba2+ current was elicited in a whole-cell recording by 50-millisecond steps from −70 to + 10 mV delivered every 10 s. Five pulses were applied in control solution, then NNCB-2 (n = 4) or CNCB-2 (n = 4 to 5) was applied for 3 min with no activation of channels and then depolarizing pulses were resumed for 50 s (in the continuing presence of drug). Then, the cell was perfused with drug-free solution for 3 min without stimulation and then depolarizing pulses were resumed for 50 s to assay recovery. (B) Slow inhibition of N-type Ca2+ channels by intracellularly applied CNCB-2. 300 µM CNCB-2 applied in the pipette solution (green triangles) produced inhibition that developed relatively slowly over several minutes (green triangles, mean ± SEM, n = 3). The time course of inhibition was similar to that of 100 µM CNCB-2 applied externally (black circles, mean ± SEM, n = 4) and slower than 300 µM CNCB-2 applied externally (red circles, mean ± SEM, n = 4); data points for external application from Figure 2. Source data can be found in Source data 1.
Figure 4
Dose-dependent inhibition of native N-type Ca2+ channels in mouse sympathetic neurons by CNCB-2 applied extracellularly.
(A) Time course of inhibition by 10 µM CNCB-2. Current carried by 5 mM Ba2+ was evoked by 50 ms steps from −70 to +10 mV delivered every 3 s. The external solution contained 5 μM nimodipine to block L-type calcium channels and 1 μM TTX to block sodium channels. Inset: Current before and after application of CNCB-2. Tail currents in control trace are truncated. (B) Current remaining in CNCB-2 applied at 3, 10, or 30 µM (mean ± SEM, n = 5 for 3 and 10 μM CNCB-2, n = 6 for 30 µM CNCB-2). Experiments performed at 37°C. Source data can be found in Source data 1.
Figure 5
CNCB-2 applied extracellularly inhibits Nav1.7 sodium channels.
(A) Time course of inhibition by 3 µM CNCB-2. Current was evoked by 10 ms steps from −70 to 0 mV delivered every 5 s. Mean ± SEM, n = 5. (B) Inhibition by 3 µM CNCB-2 at different holding potentials. Each holding potential was established for 2 s before a test pulse to 0 mV. (C) Collected results showing inhibition by 3 µM CNCB-2 as a function of holding potential, with current normalized to largest current in control (from a holding potential of −120 mV). Filled symbols show mean ± SEM, n = 5. Solid lines are drawn according to the Boltzmann equation 1/(1 + exp((V - Vh)/k)), where V is holding voltage, Vh is voltage of half-maximal availability, and k is the slope factor. Control: Vh = −63 mV, k = 6.5 mV; 3 µM CNCB-2: Vh = −71 mV, k = 7.2 mV. Dashed red line: fit for CNCB-2 data scaled to 1. Experiments performed at 37°C. Source data can be found in Source data 1.
Figure 6
Use-dependent inhibition of Nav1.7 sodium channels by externally-applied CNCB-2 compared to lidocaine and bupivacaine.
(A) Inhibition of Nav1.7 current by 3 µM CNCB-2 applied with stimulation at 0.1 Hz (20-msec depolarizations from −100 mV to 0 mV) for two minutes followed by two minutes of stimulation at 10 Hz, a return to 0.1 Hz stimulation and wash-out of compound. Black symbols: same pulse protocol in the absence of drug, recorded before application of drug. (B) Same protocol with 30 µM lidocaine. (C) Same protocol with 10 µM bupivacaine. (D) Collected results showing current at the end of 2 min of 10 Hz stimulation relative to that before application of drug. Mean ± SEM, n = 12 for no drug, n = 5 for 3 µM CNCB-2, n = 6 for 30 µM lidocaine, n = 5 for 10 µM bupivacaine. Experiments performed at 37°C. Source data can be found in Source data 1.
Figure 7
Inhibition of action potential generation in mouse DRG neurons by CNCB-2.
(A) Action potential firing evoked by injections of 40 pA, 150 pA, and 200 pA in a small-diameter mouse DRG neuron before and after 5 min exposure to 3 µM CNCB-2. Resting potential in CNCB-2 was adjusted to match the resting potential in control (near −67 mV) by injection of −20 pA. (B) Collected results showing the number of action potentials evoked by 1 s current injections of increasing sizes before and after 5 min exposure to 3 µM CNCB-2. Resting potentials in CNCB-2 were adjusted to match the resting potential in control by injection of steady holding current. Mean ± SEM, n = 4. Experiments at 37°C. Source data can be found in Source data 1.
Figure 8
Inhibition of TTX-resistant sodium current in mouse DRG neurons by CNCB-2.
(A) Time-course of inhibition of TTX-resistant sodium current in a small mouse DRG neuron by 3 µM CNCB-2. TTX-resistant sodium current was isolated by solutions containing 300 nM TTX. Current was evoked by a 10-msec step depolarization from −80 mV to −10 mV delivered once every 5 s. Inset: currents before and after CNCB-2. (B) Collected results showing current after application of 3 µM CNCB-2 (n = 6) or 10 µM CNCB-2 (n = 4) for long enough to reach steady-state (10–15 min for 3 µM CNCB-2 and 5–10 min for 10 µM CNCB-2). Experiments at 37°C. Source data can be found in Source data 1.
Figure 9
Effect of CNCB-2 in mouse pain models.
(A) Inhibition of paw withdrawal in paw incision model of post-operative pain. Threshold for response to von Frey filaments tested 1, 4 and 8 hr after injection of CNCB-2 into an injured paw 24 hr after the incisional injury (5 mm incision). Mean ± SEM for 50% withdrawal threshold (n = 8 for each group). (B) Inhibition by CNCB-2 of paw withdrawal in the zymosan model of inflammatory pain. Either 10 μL of CNCB-2 (30 mM) or vehicle (5% DMSO in normal saline) was injected in hind paw. One hour later the same paw was injected subcutaneously with 20 μL of zymosan (5 mg/ml in saline) and tested 4 hr after the zymosan injection by the von Frey test (Mean ± SEM for 50% withdrawal threshold, n = 5 for each group). (C) Direct analgesic effect of CNCB-2: inhibition of paw withdrawal by 10 μL of CNCB-2 (30 mM) injected into uninjured paws (n = 8 for each group). Source data can be found in Source data 1.
Figure 10
Inhibition of CGRP release and neurogenic lung inflammation by NNCB-2 and CNCB-2.
(A) Effect of 30 µM NNCB-2 or 30 µM CNCB-2 on release of CGRP induced by application of 50 mM KCl to DRG cultures (p=0.15 for 30 µM NNCB-2 (n = 4) compared to 50 mM KCl with no drug (n = 4), p=0.028 for 30 µM CNCB-2 (n = 8) compared to 50 mM KCl with no drug (n = 4); one-tailed t-test for non-homoscedastic data). (B) Effect of 100 µM NNCB-2 or 30 µM CNCB-2 on inflammation-associated immune cells in broncheoalveolar lavage fluid in lungs from mice with ovalbumin-induced lung inflammation. p=0.019 for CD45+ cells from ovalbumin-exposed mice application of 100 µM NNCB-2 (n = 8) compared to vehicle (n = 8); p=0.014 for CD45+ cells from ovalbumin-exposed mice with application of 30 µM CNCB-2 (n = 7) compared to vehicle (n = 8). p=0.031 for CD3+ cells from ovalbumin-exposed mice with application of 100 µM NNCB-2 (n = 8) compared to vehicle (n = 8); p=0.028 for CD3+ cells from ovalbumin-exposed mice with application of 30 µM CNCB-2 (n = 7) compared to vehicle (n = 8). p=0.10 for macrophages from ovalbumin-exposed mice with application of 100 µM NNCB-2 (n = 8) compared to vehicle (n = 8); p=0.11 for macrophages from ovalbumin-exposed mice with application of 30 µM CNCB-2 (n = 7) compared to vehicle (n = 8). p=0.008 for eosinophils from ovalbumin-exposed mice with application of 100 µM NNCB-2 (n = 8) compared to vehicle (n = 8); p=0.005 for eosinophils from ovalbumin-exposed mice with application of 30 µM CNCB-2 (n = 7) compared to vehicle (n = 8); one-tailed t-test for non-homoscedastic data. Source data can be found in Source data 1.
Tables
Key resources table
| Reagent type | Designation | Source or reference | Identifiers | Additional information |
|---|---|---|---|---|
| Strain (Mus musculus) | Swiss Webster CFW | Charles River | Cat#024 | |
| Strain (Mus musculus) | C57BL6/J | Jackson Lab | 000664 | |
| Strain (Mus musculus) | BALB/c | Jackson Lab | 001026 | |
| Cell line | rat Cav2.2 tsA201 cell line | PMID: 15201306 | Line #201719 | Dr. Diane Lipscombe, Brown University |
| Cell line | human Nav1.7 HEK cell line | PMID: 22442564 | Dr. Sooyeon Jo, Harvard Medical School | |
| Antibody | FITC anti-mouse CD45 | BD Biosciences | Cat 553079 RRID:AB_394609 | |
| Antibody | PR anti-mouse Siglec-F | BD Biosciences | Cat 552126 RRID:AB_394341 | |
| Antibody | APC anti-mouse GR-1 | Thermo Fisher | Cat 17-5931-81 RRID:AB_469475 | |
| Antibody | PE-Cy7 anti-mouse CD3e | Thermo Fisher | Cat 25-0031-81 RRID:AB_469571 | |
| Antibody | PerCP anti-mouse F4/80 | Biolegend | Cat 123125 RRID:AB_893495 | |
| Commercial assay or kit | MycoAlert PLUS Mycoplasma Detection Kit | Lonza | LT07-703 | |
| Commercial assay or kit | Rat CGRP Enzyme Immunoassay Kit | Bertin Pharma/Cayman Chemical | #589001 | |
| Chemical compound | NNCB-2 (3-Cyclopentylmethylsulfanyl-2-(3,3-dimethyl-butylamino)-N-(4-methoxy-benzyl)-propionamide) | This paper | Synthesized by Sundia MediTech, structure verified by NMR and mass spectrometry. | |
| Chemical compound | CNCB-2 ([2-Cyclopentylmethylsulfanyl-1-(4-methoxy-benzylcarbamoyl)-ethyl]−(3,3-dimethyl-butyl)-dimethyl-ammonium; chloride salt) | This paper | Synthesized by Sundia MediTech, structure verified by NMR and mass spectrometry. | |
| Chemical compound | Papain | Worthington Biochemical | LS003126 | |
| Chemical compound | Collagenase Type I | Sigma | 10103578001 | |
| Chemical compound | Dispase Type II | Sigma | 4942078001 | |
| Chemical compound | L-15 | Invitrogen | 11415–064 | |
| Chemical compound | Nerve growth factor | Invitrogen | 13290–010 | |
| Chemical compound | Neurobasal A Medium | Invitrogen | 10888–022 | |
| Chemical compound | B-27 | Invitrogen | 17504–010 | |
| Chemical compound | Penicillin-Streptomycin | Invitrogen | 15140–122 | |
| Chemical compound | Fetal calf serum | Invitrogen | 10082–147 | |
| Chemical compound | Minimal Essential Medium | American Tissue Type Collection | EMEM 30–2003 | |
| Chemical compound | Hank's Balanced Salt Solution | Gibco | 14170–112 | |
| Chemical compound | DMEM/F12 | Gibco | 11330–032 | |
| Chemical compound | Tetrodotoxin w/citrate | Abcam | Ab120055 | |
| Chemical compound | Zymosan | Sigma | Z4250 | |
| Software | Clampex | Molecular Devices | Versions 9.2, 10.3.1.5 RRID:SCR_011323 | https://www.moleculardevices.com |
| Software | Igor Pro | Wavemetrics | Version 6.12A RRID:SCR_000325 | https://www.wavemetrics.com |
| Software | DataAccess | Bruxton Corporation | http://www.bruxton.com/DataAccess/index.html | |
| Software | GraphPad Prism | Graph Pad | RRID:SCR_002798 | Version 5 |
Additional files
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Source data 1
- https://cdn.elifesciences.org/articles/48118/elife-48118-data1-v1.xlsx
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Transparent reporting form
- https://cdn.elifesciences.org/articles/48118/elife-48118-transrepform-v1.docx
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Novel charged sodium and calcium channel inhibitor active against neurogenic inflammation
eLife 8:e48118.
https://doi.org/10.7554/eLife.48118
