From the First Department of Medicine, Faculty of Medicine (I.E.-B., Z.Z., H.L., X.L., G.Y., S.L., K.S., J.-D.S., M.B., X.-B.Z., I.A.) and Department of Dermatology, Venereology and Allergology (J.U.), University Medical Centre Mannheim, University of Heidelberg, Germany; DZHK (German Center for Cardiovascular Research), Partner Sites, Heidelberg-Mannheim and Göttingen (I.E.-B., Z.Z., H.L., G.Y., S.L., W.-H.Z., L.C., J.U., T.W., R.B., A.R., D.T., P.M., H.A.K., C.S., M.B., X.-B.Z., O.J.M., I.A.); Institute of Pharmacology and Toxicology, University of Göttingen, Germany (W.-H.Z.); Stem Cell Unit, Clinic for Cardiology and Pneumology, University Medical Center Göttingen, Germany (L.C.); Skin Cancer Unit, German Cancer Research Center (DKFZ), Heidelberg (J.U.); Institute of Experimental and Clinical Pharmacology and Toxicology (T.W.) and Department of Hematology and Oncology (D.N., J.W.), Medical Faculty Mannheim, University of Heidelberg, Germany; Institute for Transfusion Medicine and Immunology, Mannheim, Germany (K.B.); Internal Medicine III, University Hospital Heidelberg, Germany (R.B., A.R., R.P.-W., K.R., D.T., P.M., H.A.K., C.S., O.J.M.); Institute of Experimental Cardiovascular Medicine, University Heart Centre Freiburg, Germany (U.R.); Medical Faculty, University of Freiburg, Germany (U.R.); and Key Laboratory of Medical Electrophysiology of Ministry of Education, Institute of Cardiovascular Research, Southwest Medical University, Luzhou, China (H.L., X.-B.Z.).
Circ Genom Precis Med. 2018 Mar;11(3):e001893. doi: 10.1161/CIRCGEN.117.001893.
Limb-Girdle muscular dystrophies (LGMD) are a heritable group of genetically determined disorders with a primary involvement of the pelvic or shoulder girdle musculature with partially cardiac manifestation, such as dilated cardiomyopathy (DCM) and life-threatening tachyarrhythmia. We report here that human induced pluripotent stem cell (hiPSC)-derived cardiomyocytes from a patient with LGMD2I and DCM associated with recurrent ventricular tachycardia displayed ion channel dysfunction and abnormality of calcium homeostasis.
Dermal fibroblasts obtained from a patient with LGMD2I harboring a fukutin-related protein gene mutation (826C>A; Leu276Ile) and 3 healthy donors were reprogrammed to hiPSCs. The hiPSCs were differentiated into cardiomyocytes and used for biological and electrophysiological studies.
Compared with hiPSC cardiomyocytes from the healthy donors, the hiPSC cardiomyocytes from the patient exhibited abnormal action potentials characterized by reduced amplitude and upstroke velocity. The peak and late Na channel currents (I) as well as the peak L-type calcium channel currents were significantly reduced. The expression of SCN5A and CACNA1C was reduced in DCM cardiomyocytes, consistent with reduction of I and L-type calcium channel currents. In addition, the rapidly activating delayed rectifier potassium current (I) was reduced, whereas the transient outward current (I) and slowly activating delayed rectifier potassium current (I) were similar in DCM and control cardiomyocytes. Finally, a significant reduction of systolic and diastolic intracellular Ca concentrations was detected in DCM cardiomyocytes.
This study demonstrates that patient-specific hiPSC cardiomyocytes can recapitulate some phenotypic properties of LGMD2I with DCM and provide a platform for studies on the cardiac events in LGMD.
肢带型肌营养不良症（LGMD）是一组遗传性疾病，主要累及骨盆或肩部带肌，部分伴有心脏表现，如扩张型心肌病（DCM）和危及生命的室性心动过速。我们在此报告，一位 LGMD2I 患者和伴有复发性室性心动过速的 DCM 的人诱导多能干细胞（hiPSC）衍生的心肌细胞显示离子通道功能障碍和钙稳态异常。
从一位携带有福ukin 相关蛋白基因突变（826C>A；Leu276Ile）的 LGMD2I 患者和 3 位健康供体的皮肤成纤维细胞中获得的人诱导多能干细胞（hiPSC）。将 hiPSC 分化为心肌细胞，并用于生物学和电生理学研究。
与健康供体的 hiPSC 心肌细胞相比，来自患者的 hiPSC 心肌细胞表现出异常的动作电位，其特征为幅度和上升速度降低。峰值和晚期 Na 通道电流（I）以及峰值 L 型钙通道电流明显降低。DCM 心肌细胞中 SCN5A 和 CACNA1C 的表达减少，与 I 和 L 型钙通道电流减少一致。此外，快速激活延迟整流钾电流（I）降低，而瞬时外向电流（I）和缓慢激活延迟整流钾电流（I）在 DCM 和对照心肌细胞中相似。最后，在 DCM 心肌细胞中检测到收缩期和舒张期细胞内 Ca 浓度的显著降低。
本研究表明，患者特异性 hiPSC 心肌细胞可再现具有 DCM 的 LGMD2I 的一些表型特征，并为 LGMD 中的心脏事件研究提供了一个平台。
