K+ efflux through two-pore domain K+ channels is required for mouse embryonic development

Abstract

Numerous studies have suggested that K C channels regulate a wide range of physiological processes in mammalian cells. However, little is known about the specific function of K C channels in germ cells. In this study, mouse zygotes were cultured in a medium containing K C channel blockers to identify the functional role of K C channels in mouse embryonic development. Voltage-dependent K C 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 w38% 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.

A role for two‐pore potassium (K2P) channels in endometrial epithelial function

“…This finding is consistent with molecular expression of K2P channels in epithelia of taste buds [17], airways [18][19][20], gastrointestinal mucosa [21] and human nephron [22]. In relation to reproductive physiology, various K2P channels have been reported in sperm [23] and blastocysts [24] where culturing mouse zygotes in media supplemented with K2P blockers or using siRNA to knockdown KCNK expression significantly inhibited mouse blastocyst formation [24]. Virtually undetectable levels of TRAAK expression in the cell line mirror low expression in peripheral organs compared with the brain where TRA-AK is highly expressed [14,25].…”

Acid stress mediated adaptive divergence in ion channel function during embryogenesis in Rana arvalis

“…However, relatively little is known on the function of specific channels and pumps during embryogenesis. Studies in model systems, such as mouse, chicken and Xenopus , indicate dynamic expression of ion channels and pumps during embryogenesis 4 5 6 —whereas studies on natural populations facing variable ecological conditions are essentially missing.…”

A microgripper sensor device capable of detecting ion efflux from whole cells

“…However, given that the sensor device mechanically stresses the cell, the signalling response is likely to be dominated by mechanically gated ion channels. There are very few investigations into the role of ion-channel activity in embryonic development but potassium channels are known to exist [18,19,20]. Our results indicated that signal responses from mechanically stressing cells directly correlate to the movement of ions, specifically K+ ions in this case.…”