The identification of circulating KCNH2 current-inhibitory factor in anti-SSA antibody-positive patients with pregnancies

• Project/Area Number: 26860561
• Research Category: Grant-in-Aid for Young Scientists (B)
• Allocation Type: Multi-year Fund
• Research Field: Cardiovascular medicine
• Research Institution: Okayama University
• Principal Investigator: SUGIYAMA Hiroki 岡山大学, 医学部, 客員研究員 (20726137)
• Project Period (FY): 2014-04-01 – 2016-03-31
• Project Status: Completed (Fiscal Year 2015)
• Budget Amount: ¥3,900,000 (Direct Cost: ¥3,000,000、Indirect Cost: ¥900,000); Fiscal Year 2015: ¥1,950,000 (Direct Cost: ¥1,500,000、Indirect Cost: ¥450,000); Fiscal Year 2014: ¥1,950,000 (Direct Cost: ¥1,500,000、Indirect Cost: ¥450,000)
• Keywords: 抗SSA抗体 / KCNH2電流 / パッチクランプ法 / 免疫沈降 / HERG結合蛋白 / KCNH2 / 自己免疫性QT延長症候群

Outline of Final Research Achievements

The subjects in this study were anti-SSA antibody-positive patients (n=6) with pregnancies referred to department of gynecology, National Cerebral and Cardiovascular Center, Osaka, japan. Serum samples were obtained from these patients and their fetus after obtaining informed consent, and sent to our laboratory in Okayama university. HEK293 cells stably expressing KCNH2 were cultured for 1 day in a medium to which serum obtained from the study subjects had been added.
The KCNH2 current activation in these cells was studied by analysis of deactivating tail currents recorded by using the whole-cell patch-clamp technique. There were no significant differences in KCNH2 tail currents　in these patients and normal controls. HERG-binding protein was needed to be identified and abstracted by immunoprecipitation experiments using HERG-tagged fusion protein from sera obtained from subjects.