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Noriega-Navarro R, Lopez-Charcas O, Hernández-Enríquez B, Reyes-Gutiérrez PE, Martínez R, Landa A, Morán J, Gomora JC, Garcia-Valdes J. Novel TASK channels inhibitors derived from dihydropyrrolo[2,1-a]isoquinoline. Neuropharmacology 2013; 79:28-36. [PMID: 24212057 DOI: 10.1016/j.neuropharm.2013.10.028] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2012] [Revised: 10/22/2013] [Accepted: 10/27/2013] [Indexed: 01/12/2023]
Abstract
TASK channels belong to the family of K(+) channels with 4 transmembrane segments and 2 pore domains (4TM/2P) per subunit. These channels have been related to apoptosis in cerebellar granule neurons (CGN), as well as cancer in other tissues. TASK current is regulated by hormones, neurotransmitters, anesthetics and divalent cations, which are not selective. Recently, there has been found some organic compounds that inhibit TASK current selectively. In order to find other modulators, we report here a group of five dihydropyrrolo[2,1-a]isoquinolines (DPIs), four of them with putative anticancer activity, that were evaluated on TASK-1 and TASK-3 channels. The compounds 1, 2 and 3 showed IC50 < 320 μM on TASK-1 and TASK-3, intermediate activity on TASK-1/TASK-3 heterodimer, moderate effect over hslo and TREK-1 (500 μM), and practically not inhibition on Shaker-IR, herg and IRK2.1 potassium channels, when they were expressed heterologously in Xenopus laevis oocytes. In rat CGN, 500 μM of these three compounds induced a decrement by >39% of the TASK-carried leak current. Finally, only compound 1 showed significant protection (∼36%) against apoptotic death of CGN induced by K(+) deprivation. These results suggest that DPI compounds could be potential candidates for designing new selective inhibitors of TASK channels.
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Affiliation(s)
- R Noriega-Navarro
- Departamento de Química Analítica, Facultad de Química, Universidad Nacional Autónoma de México (UNAM), Ciudad Universitaria, México City 04510, Mexico
| | - O Lopez-Charcas
- Departamento de Neuropatología Molecular, División de Neurociencias, Instituto de Fisiología Celular, Universidad Nacional Autónoma de México (UNAM), Ciudad Universitaria, México City 04510, Mexico
| | - B Hernández-Enríquez
- Departamento de Neurodesarrollo y Fisiología, División de Neurociencias, Instituto de Fisiología Celular, Universidad Nacional Autónoma de México (UNAM), Ciudad Universitaria, México City 04510, Mexico
| | - P E Reyes-Gutiérrez
- Departamento de Química Orgánica, Instituto de Química, Universidad Nacional Autónoma de México (UNAM), Ciudad Universitaria, México City 04510, Mexico
| | - R Martínez
- Departamento de Química Orgánica, Instituto de Química, Universidad Nacional Autónoma de México (UNAM), Ciudad Universitaria, México City 04510, Mexico
| | - A Landa
- Departamento de Microbiología y Parasitología, Facultad de Medicina, Universidad Nacional Autónoma de México (UNAM), Ciudad Universitaria, México City 04510, Mexico
| | - J Morán
- Departamento de Neurodesarrollo y Fisiología, División de Neurociencias, Instituto de Fisiología Celular, Universidad Nacional Autónoma de México (UNAM), Ciudad Universitaria, México City 04510, Mexico
| | - J C Gomora
- Departamento de Neuropatología Molecular, División de Neurociencias, Instituto de Fisiología Celular, Universidad Nacional Autónoma de México (UNAM), Ciudad Universitaria, México City 04510, Mexico
| | - J Garcia-Valdes
- Departamento de Química Analítica, Facultad de Química, Universidad Nacional Autónoma de México (UNAM), Ciudad Universitaria, México City 04510, Mexico.
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Garcia-Valdes J, Zamudio FZ, Toro L, Possani LD, Possan LD. Slotoxin, alphaKTx1.11, a new scorpion peptide blocker of MaxiK channels that differentiates between alpha and alpha+beta (beta1 or beta4) complexes. FEBS Lett 2001; 505:369-73. [PMID: 11576530 DOI: 10.1016/s0014-5793(01)02791-0] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
A novel peptide from Centruroides noxius Hoffmann scorpion venom was isolated and sequenced. The 37 amino acid peptide belongs to the charybdotoxin sub-family (alphaKTx1) and was numbered member 11. alphaKTx1.11 has 75% sequence identity with iberiotoxin and 54% with charybdotoxin. alphaKTx1.11 revealed specificity for mammalian MaxiK channels (hSlo), thus, was named slotoxin. Slotoxin blocks the MaxiK pore-forming alpha subunit reversibly (K(d)=1.5 nM). Slotoxin association with alpha+beta (beta1 or beta4) channels was approximately 10 times slower than iberiotoxin and charybdotoxin, leading to a lack of effect on alpha+beta4 when tested at 100 nM for 5 min. Thus, slotoxin is a better tool to distinguish MaxiK alpha+beta complexes.
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Affiliation(s)
- J Garcia-Valdes
- Department of Molecular Recognition and Structural Biology, Institute of Biotechnology, National Autonomous University of Mexico, Cuernavaca, Mexico
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