NADPH oxidase 2-derived superoxide downregulates endothelial K Ca3.1 in preeclampsia

Shinkyu Choi, Ji Aee Kim, Hye Young Na, Ji Eun Kim, Seonghee Park, Ki Hwan Han, Young Ju Kim, Suk Hyo Suh

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30 Scopus citations


Endothelial dysfunction is associated with KCa3.1 dysfunction and contributes to the development of hypertension in preeclampsia. However, evidence of endothelial KCa3.1 dysfunction in the vascular system from women with preeclampsia is still lacking. Therefore, we examined whether endothelial KCa3.1 dysfunction occurs in vessels from women with preeclampsia. We compared KCa3.1 and NADPH oxidase (NOX) expression in umbilical vessels and primary cultured human umbilical vein endothelial cells (HUVECs) from normal (NP; n=17) and preeclamptic pregnancy (PE; n=19) and examined the effects of plasma from NP or PE on KCa3.1 and NOX2 expression in primary cultured HUVECs from NP or human uterine microvascular endothelial cells. The endothelial KCa3.1 was downregulated, and NOX2 was upregulated, in umbilical vessels and HUVECs from PE, compared with those from NP. In addition, HUVECs from PE showed a significant decrease in K Ca3.1 current. Plasma from PE induced KCa3.1 down regulation, NOX2 upregulation, phosphorylated-p38 mitogen-activated protein kinase downregulation, and superoxide generation, and these effects were prevented by antioxidants (tempol or tiron), NOX2 inhibition, or anti-lectin-like oxidized low-density lipoprotein (LDL) receptor 1 (LOX1) antibody. Oxidized LDL and the superoxide donor xanthine/xanthine oxidase mixture induced KCa3.1 downregulation. In contrast, plasma from PE did not generate hydrogen peroxide, and the hydrogen peroxide donor tert-butylhydroperoxide induced KCa3.1 upregulation. These results provide the first evidence that plasma from PE generates superoxide via a LOX1-NOX2-mediated pathway and downregulates endothelial KCa3.1, which may contribute to endothelial dysfunction and vasculopathy in preeclampsia. This suggests KCa3.1as a novel target for patients with preeclampsia.

Original languageEnglish
Pages (from-to)10-21
Number of pages12
JournalFree Radical Biology and Medicine
StatePublished - Apr 2013

Bibliographical note

Funding Information:
This research was supported by the Basic Science Research Program through the National Research Foundation of Korea funded by the Ministry of Education, Science, and Technology ( R01-2010-000-10466-0 ) and by a grant from the Korean Health Technology Research and Development Project , Ministry for Health, Welfare, and Family Affairs, Republic of Korea ( A100955 ).


  • Anti-lectin-like oxidized low-density lipoprotein receptor 1
  • Ca-activated K channel
  • Free radicals
  • Hypertension
  • NADPH oxidase
  • Oxygen radicals


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