title: K(+) efflux through two-pore domain K(+) channels is required for mouse embryonic development.
abstract: Numerous studies have suggested that K(+) channels regulate a wide range of physiological processes in mammalian cells. However, little is known about the specific function of K(+) channels in germ cells. In this study, mouse zygotes were cultured in a medium containing K(+) channel blockers to identify the functional role of K(+) channels in mouse embryonic development. Voltage-dependent K(+) channel blockers, such as tetraethylammonium and BaCl(2), had no effect on embryonic development to the blastocyst stage, whereas K(2P) channel blockers, such as quinine, selective serotonin reuptake inhibitors (fluoxetine, paroxetine, and citalopram), gadolinium trichloride, anandamide, ruthenium red, and zinc chloride, significantly decreased blastocyst formation (P<0.05). RT-PCR data showed that members of the K(2P) channel family, specifically KCNK2, KCNK10, KCNK4, KCNK3, and KCNK9, were expressed in mouse oocytes and embryos. In addition, their mRNA expression levels, except Kcnk3, were up-regulated by above ninefold in morula-stage embryos compared with 2-cell stage embryos (2-cells). Immunocytochemical data showed that KCNK2, KCNK10, KCNK4, KCNK3, and KCNK9 channel proteins were expressed in the membrane of oocytes, 2-cells, and blastocysts. Each siRNA injection targeted at Kcnk2, Kcnk10, Kcnk4, Kcnk3, and Kcnk9 significantly decreased blastocyst formation by ~38% compared with scrambled siRNA injection (P<0.05). The blockade of K(2P) channels acidified the intracellular pH and depolarized the membrane potential. These results suggest that K(2P) channels could improve mouse embryonic development through the modulation of gating by activators.
authors.affiliation: Department of Physiology, Institute of Health Sciences, Gyeongsang National University School of Medicine, 90 Chilam, Jinju 660-751, South Korea.
authors.forename: Chang-Gi
authors.initials: CG
authors.lastname: Hur
authors.forename: Eun-Jin
authors.initials: EJ
authors.lastname: Kim
authors.forename: Seong-Keun
authors.initials: SK
authors.lastname: Cho
authors.forename: Young-Woo
authors.initials: YW
authors.lastname: Cho
authors.forename: Sook-Young
authors.initials: SY
authors.lastname: Yoon
authors.forename: Hyun-Min
authors.initials: HM
authors.lastname: Tak
authors.forename: Chang-Woon
authors.initials: CW
authors.lastname: Kim
authors.forename: Changyong
authors.initials: C
authors.lastname: Choe
authors.forename: Jaehee
authors.initials: J
authors.lastname: Han
authors.forename: Dawon
authors.initials: D
authors.lastname: Kang
mesh_terms: D000818:Animals; D001755:Blastocyst / Q000187:drug effects / Q000378:metabolism*; D046149:Embryo Culture Techniques; D047108:Embryonic Development; D018507:Gene Expression Regulation, Developmental; D006863:Hydrogen-Ion Concentration; D007150:Immunohistochemistry; D015640:Ion Channel Gating; D008564:Membrane Potentials; D051379:Mice; D008813:Mice, Inbred ICR; D011188:Potassium / Q000378:metabolism*; D026902:Potassium Channel Blockers / Q000494:pharmacology; D024683:Potassium Channels, Tandem Pore Domain / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D034622:RNA Interference; D012333:RNA, Messenger / Q000378:metabolism; D060888:Real-Time Polymerase Chain Reaction; D015053:Zygote / Q000187:drug effects / Q000378:metabolism*
chemical_list: D026902:Potassium Channel Blockers; D024683:Potassium Channels, Tandem Pore Domain; D012333:RNA, Messenger; D011188:Potassium