SAR Analysis for the identification of selective inhibitors of the transient receptor potential cation channel C4 (TRPC4) in TRPC6 expressing cells: MPD Assay CRC
Assay Implementation: Melissa Miller, Shunyou Long M.S., David Meyers Ph.D., Meng Wu Ph.D., Owen McManus Ph.D. ..more
BioActive Compounds: 16
Data Source: Johns Hopkins Ion Channel Center (JHICC)
BioAssay Type: Confirmatory, Concentration-Response Relationship Observed
Source (MLPCN Center Name): Johns Hopkins Ion Channel Center (JHICC)
Center Affiliation: Johns Hopkins University, School of Medicine
Screening Center PI: Min Li, Ph.D.
Assay Provider: Mike Zhu Ph.D., Ohio State University
Network: Molecular Libraries Probe Production Centers Network (MLPCN)
Grant Proposal Number: 1 R21 NS056942-01
Grant Proposal PI: Mike Zhu Ph.D.
Assay Implementation: Melissa Miller, Shunyou Long M.S., David Meyers Ph.D., Meng Wu Ph.D., Owen McManus Ph.D.
Name: SAR Analysis for the identification of selective inhibitors of the transient receptor potential cation channel C4 (TRPC4) in TRPC6 expressing cells: MPD Assay CRC
See the related assay (PubChem AID: 2247)
The purpose of this assay is to assess the specificity of compounds identified as inhibitors of the transient receptor potential cation channel C4 (TRPC4). This specificity screen is to eliminate any compounds that interact with the TRPC6 channel, rather than TRPC4 mu-opioid receptor expressing HEK293 cells. The protocol as in AID 2553 is used for this assay except each compound is tested at 10 concentrations. Compound inhibition of TRPC6 was tested in at least duplicate using a membrane potential sensitive dye.
1. Cell culture: Cells are routinely cultured in DMEM/high glucose medium, supplemented with 10% Heat Inactivated Fetal Bovine Serum (HiFBS), 50 IU/ml penicillin, 50 ug/mL streptomycin, and 400 ug/mL G418
2. Cell plating: Add 50 ul/well of 300,000 cells/ml re-suspended in DMEM/high glucose medium with 10% HiFBS, 50 IU/ml penicillin, and 50 ug/mL streptomycin
3. Incubate overnight at 37C and 5% CO2
4. Remove medium and add 20 ul/well of Membrane Potential Dye
5. Incubate 45 minutes at room temperature (RT) in the dark
6. Prepare 7.5X compound plates and control plates on Cybi-Well system: test compounds are prepared using assay buffer; controls are assay buffer (EC0), ECmax of Acetylcholine
7. Load cell plates to Hamamatsu FDSS 6000 kinetic imaging plate reader
8. Measure fluorescence for 5 seconds at 1Hz to establish baseline
9. Add 4ul of 7.5x compound stock into the cell plates.
10. Incubate plates for 110 seconds
11. Add 6ul maximally activating concentration of Acetylcholine (Acetylcholine ECmax) and read for another 110 seconds.
12. Calculate ratio readout as F(max-min)/F0 and integrated ratio readout
13. Calculate the average and standard deviation for negative and positive controls in each plate, as well as Z' factors
14. IC50 and Hill Constant calculation from replicates was generated using Microcol Origin 6.0
15. Outcome assignment: If the test compound causes a maximum inhibition of TRPC6 greater than 30% in any concentration tested and a dose response curve is generated the compound is considered to be active (outcome=2). If the test compound does not cause inhibition of TRPC6 at any concentration tested or a dose response is not generated, the compound is designated as inactive (outcome=1).
16. Score assignment: Compounds with an IC50 less than 1uM are given a score of 100, 1uM-5uM a score of 75, 5uM-10uM a score of 50, 10uM-20uM a score of 25 and any compound with an IC50 greater than 20uM or those that are designated inactive in the outcome are given a score of 0
List of reagents
1. TRPC6-expressing HEK293 Cells (provided by Assay Provider Michael Zhu, Ohio State University)
2. Medium: Dulbecco's Modified Eagle Medium (D-MEM) (1X), liquid (high glucose) w/L-Glut (Sigma, Cat# D5796-500ML)
3. Heat Inactivated Fetal Bovine Serum (Sigma, Cat# F2442)
4. 100x Penicillin-Streptomycin (Mediatech, Cat# 30-001-CI)
5. CellStripper (Mediatech, Cat# 25-056-Cl)
6. G418: (Invitrogen, Cat# 11811-031)
7. HEPES (Sigma, Cat# H4034)
8. 10XHBSS (#Invitrogen Cat# 14065056)
9. Acetylcholine chloride (Sigma, Cat# A6625)
10. 2-APB (Sigma, Cat# D9754)
11. Membrane Potential Assay Kit, Blue (Molecular Devices, Cat# R8034)
12. Triple-layer flask (VWR, Cat# 62407-082)
13. BD Biocoat 384-well plates (BD, Cat# (35)4663 and Lot# 8281903)
Possible artifacts of this assay can include, but are not limited to: non-intended chemicals, dust in or on wells of the microtiter plate, or compounds that quench or emit light or fluorescence within the well. All test compound concentrations reported are nominal; the specific concentration for a particular test compound may vary based upon the actual sample provided by the MLSMR.
* Activity Concentration. ** Test Concentration.
Data Table (Concise)