| First Author | Xu B | Year | 2017 |
| Journal | Biol Reprod | Volume | 96 |
| Issue | 3 | Pages | 542-550 |
| PubMed ID | 28339658 | Mgi Jnum | J:243960 |
| Mgi Id | MGI:5912739 | Doi | 10.1095/biolreprod.116.143974 |
| Citation | Xu B, et al. (2017) Acute cell volume regulation by Janus kinase 2-mediated sodium/hydrogen exchange activation develops at the late one-cell stage in mouse preimplantation embryos. Biol Reprod 96(3):542-550 |
| abstractText | Early preimplantation embryos are extremely sensitive to dysregulation of cell volume, which can lead to developmental arrest. It was previously shown that mouse embryos at the two-cell stage respond to a cell volume decrease by quickly activating Na+/H+ exchange via a signaling mechanism that involves the tyrosine kinase Janus kinase 2 (JAK2). However, it was not known whether this mechanism is active at the one-cell stage, when embryos are most sensitive to perturbed cell volume. Na+/H+ exchanger activity elicited by an induced cell volume decrease was significantly lower at the mid one-cell stage than at the late one-cell stage or during the two-cell stage. This activity could be completely blocked by the broad specificity tyrosine kinase inhibitor genistein at either stage, but only at the two-cell stage was there a substantial component of activity that was sensitive to low concentrations of the JAK2-selective inhibitors TG101348 or ruxolitinib. Western blots to detect active JAK2 phosphorylated on tyrosine Y1007/8 revealed that JAK2 became substantially phosphorylated in response to a cell volume decrease at the mid two-cell, but not mid one-cell stage. Such cell volume decrease-induced JAK2 phosphorylation appeared by the late one-cell stage. At least in part this appears to be due to an increase in total JAK2 protein at the late one-cell stage. Furthermore, TG101348 impaired maintenance of cell volume at the two-cell, but not mid one-cell, stages. Thus, cell volume homeostasis requiring Na+/H+ exchange signaled by JAK2 first becomes prominent during mouse embryonic development at the late one-cell stage. |
