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Patient-Specific Induced Pluripotent Stem-Cell Models
; `! X! K" w# f* ffor Long-QT Syndrome
! t4 m, W) _* ?0 ]: }" H: tBACKGROUND
' ?: l* N) y" YLong-QT syndromes are heritable diseases associated with prolongation of the QT1 H4 l5 k( L1 ]# P
interval on an electrocardiogram and a high risk of sudden cardiac death due to
% u+ s5 _+ @5 X; S6 Mventricular tachyarrhythmia. In long-QT syndrome type 1, mutations occur in the8 ?, u4 q' {" Y
KCNQ1 gene, which encodes the repolarizing potassium channel mediating the delayed6 {# x% o3 p, E. ^1 t3 l
rectifier IKs current.
5 v4 R9 p3 C/ E' V& x& tMETHODS4 f L* z1 O% I7 Y# E9 p1 H
We screened a family affected by long-QT syndrome type 1 and identified an autosomal- l7 J9 p5 y6 d5 G1 N
dominant missense mutation (R190Q) in the KCNQ1 gene. We obtained4 V% h3 c: F/ O$ `! L
dermal fibroblasts from two family members and two healthy controls and infected" V( w7 h: M" m0 Q* u
them with retroviral vectors encoding the human transcription factors OCT3/4,
' d0 A+ f4 |/ ?+ ySOX2, KLF4, and c-MYC to generate pluripotent stem cells. With the use of a specific
^2 R0 x% d/ i9 k6 vprotocol, these cells were then directed to differentiate into cardiac myocytes.
" g' ?+ ~: j0 E ?! }0 qRESULTS/ |0 @. N: y* P w' A
Induced pluripotent stem cells maintained the disease genotype of long-QT syndrome* s: ], T9 K* x, E
type 1 and generated functional myocytes. Individual cells showed a “ventricular,”2 V% ~/ m* ~7 v
“atrial,” or “nodal” phenotype, as evidenced by the expression of celltype– d# O! `4 j7 Z6 A/ R
specific markers and as seen in recordings of the action potentials in single
( g3 P' L% G4 e; U) A- |cells. The duration of the action potential was markedly prolonged in “ventricular”
- m# H0 f, x. c' J5 r) @/ j Band “atrial” cells derived from patients with long-QT syndrome type 1, as compared7 w; E9 u$ h! h! l8 o6 m
with cells from control subjects. Further characterization of the role of the R190Q–3 ?' F) D# e- j
KCNQ1 mutation in the pathogenesis of long-QT syndrome type 1 revealed a dominant0 \5 ?) U. i3 H7 i8 Z7 H; Y& ~' R
negative trafficking defect associated with a 70 to 80% reduction in IKs current6 O1 n3 G) K9 ]1 E, B
and altered channel activation and deactivation properties. Moreover, we/ y0 x+ {. D: @3 D. ^
showed that myocytes derived from patients with long-QT syndrome type 1 had an
! p0 P' R- G9 Nincreased susceptibility to catecholamine-induced tachyarrhythmia and that betablockade& V4 p, n$ h1 v) P
attenuated this phenotype.& }/ N- d+ w# [$ f5 [& j, F
CONCLUSIONS. y; W% u8 E/ E- j2 S0 [# G( N. \
We generated patient-specific pluripotent stem cells from members of a family affected: ~ F# X, T- S* u4 e1 h# o% R
by long-QT syndrome type 1 and induced them to differentiate into functional Q$ g; L$ _/ J5 m
cardiac myocytes. The patient-derived cells recapitulated the electrophysiological
+ L l% W5 f8 @- K+ Kfeatures of the disorder. (Funded by the European Research Council and others.)% Z# C! Z( ]( j" x
n engl j med 363;15 nejm.org october 7, 2010! d7 W7 a, e+ c" s9 j8 e
" ]3 i" ~) l) ^ T
( N' ^' P0 ~1 jhttp://www.nejm.org/doi/pdf/10.1056/NEJMoa0908679 |
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发表于 2010-10-7 09:09
