A voltage dependent non-inactivating Na+ channel activated during apoptosis in Xenopus oocytes.
Ion channels in the plasma membrane are important for the apoptotic process. Different types of voltage-gated ion channels are up-regulated early in the apoptotic process and block of these channels prevents or delays apoptosis. In the present investigation we examined whether ion channels are up-re...
| Main Authors: | , , , |
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| Format: | Article |
| Language: | English |
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Public Library of Science (PLoS)
2014-01-01
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| Series: | PLoS ONE |
| Online Access: | https://journals.plos.org/plosone/article/file?id=10.1371/journal.pone.0088381&type=printable |
| _version_ | 1826799031556243456 |
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| author | Ulrika H Englund Jens Gertow Katarina Kågedal Fredrik Elinder |
| author_facet | Ulrika H Englund Jens Gertow Katarina Kågedal Fredrik Elinder |
| author_sort | Ulrika H Englund |
| collection | DOAJ |
| description | Ion channels in the plasma membrane are important for the apoptotic process. Different types of voltage-gated ion channels are up-regulated early in the apoptotic process and block of these channels prevents or delays apoptosis. In the present investigation we examined whether ion channels are up-regulated in oocytes from the frog Xenopus laevis during apoptosis. The two-electrode voltage-clamp technique was used to record endogenous ion currents in the oocytes. During staurosporine-induced apoptosis a voltage-dependent Na(+) current increased three-fold. This current was activated at voltages more positive than 0 mV (midpoint of the open-probability curve was +55 mV) and showed almost no sign of inactivation during a 1-s pulse. The current was resistant to the Na(+)-channel blockers tetrodotoxin (1 µM) and amiloride (10 µM), while the Ca(2+)-channel blocker verapamil (50 µM) in the bath solution completely blocked the current. The intracellular Na(+) concentration increased in staurosporine-treated oocytes, but could be prevented by replacing extracellular Na(+) with either K(+) or Choline(+). Prevention of this influx of Na(+) also prevented the STS-induced up-regulation of the caspase-3 activity, suggesting that the intracellular Na(+) increase is required to induce apoptosis. Taken together, we have found that a voltage dependent Na(+) channel is up-regulated during apoptosis and that influx of Na(+) is a crucial step in the apoptotic process in Xenopus oocytes. |
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| language | English |
| last_indexed | 2025-03-17T00:28:37Z |
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| spelling | doaj.art-9edd2761cbde4363ac31b7cd96203a632025-02-21T05:37:17ZengPublic Library of Science (PLoS)PLoS ONE1932-62032014-01-0192e8838110.1371/journal.pone.0088381A voltage dependent non-inactivating Na+ channel activated during apoptosis in Xenopus oocytes.Ulrika H EnglundJens GertowKatarina KågedalFredrik ElinderIon channels in the plasma membrane are important for the apoptotic process. Different types of voltage-gated ion channels are up-regulated early in the apoptotic process and block of these channels prevents or delays apoptosis. In the present investigation we examined whether ion channels are up-regulated in oocytes from the frog Xenopus laevis during apoptosis. The two-electrode voltage-clamp technique was used to record endogenous ion currents in the oocytes. During staurosporine-induced apoptosis a voltage-dependent Na(+) current increased three-fold. This current was activated at voltages more positive than 0 mV (midpoint of the open-probability curve was +55 mV) and showed almost no sign of inactivation during a 1-s pulse. The current was resistant to the Na(+)-channel blockers tetrodotoxin (1 µM) and amiloride (10 µM), while the Ca(2+)-channel blocker verapamil (50 µM) in the bath solution completely blocked the current. The intracellular Na(+) concentration increased in staurosporine-treated oocytes, but could be prevented by replacing extracellular Na(+) with either K(+) or Choline(+). Prevention of this influx of Na(+) also prevented the STS-induced up-regulation of the caspase-3 activity, suggesting that the intracellular Na(+) increase is required to induce apoptosis. Taken together, we have found that a voltage dependent Na(+) channel is up-regulated during apoptosis and that influx of Na(+) is a crucial step in the apoptotic process in Xenopus oocytes.https://journals.plos.org/plosone/article/file?id=10.1371/journal.pone.0088381&type=printable |
| spellingShingle | Ulrika H Englund Jens Gertow Katarina Kågedal Fredrik Elinder A voltage dependent non-inactivating Na+ channel activated during apoptosis in Xenopus oocytes. PLoS ONE |
| title | A voltage dependent non-inactivating Na+ channel activated during apoptosis in Xenopus oocytes. |
| title_full | A voltage dependent non-inactivating Na+ channel activated during apoptosis in Xenopus oocytes. |
| title_fullStr | A voltage dependent non-inactivating Na+ channel activated during apoptosis in Xenopus oocytes. |
| title_full_unstemmed | A voltage dependent non-inactivating Na+ channel activated during apoptosis in Xenopus oocytes. |
| title_short | A voltage dependent non-inactivating Na+ channel activated during apoptosis in Xenopus oocytes. |
| title_sort | voltage dependent non inactivating na channel activated during apoptosis in xenopus oocytes |
| url | https://journals.plos.org/plosone/article/file?id=10.1371/journal.pone.0088381&type=printable |
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