Chen Shaojie, Lin Yongping, Zhu Yue, Geng Le, Cui Chang, Li Zhaomin, Liu Hailei, Chen Hongwu, Ju Weizhu, Chen Minglong
Division of Cardiology, The First Affiliated Hospital of Nanjing Medical University, Nanjing, China.
Department of Cardio-Thoracic Surgery, The First Affiliated Hospital of Nanjing Medical University, Nanjing, China.
Front Cardiovasc Med. 2022 Mar 10;9:840337. doi: 10.3389/fcvm.2022.840337. eCollection 2022.
PRKAG2 cardiomyopathy is a rare progressive disease characterized by increased ventricular wall thickness and preexcitation. Dysfunction of the protein 5'-AMP-activated protein kinase (AMPK) plays a decisive role in the progression of ventricular lesions. Although patients with the -R302Q mutation have a high incidence of atrial fibrillation (AF), the molecular mechanism contributing to the disease remains unclear. We carried out whole-genome sequencing with linkage analysis in three affected members of a family. Atrial samples were obtained from the proband surgical intervention. Control atrium biopsies were obtained from patients with persistent AF. Pathological changes were analyzed using the hematoxylin and eosin (H&E), Masson, and periodic acid-Schiff (PAS) staining. The AMPK signaling pathway was investigated by western blot. A murine atrial cardiomyocyte cell line (HL-1) and human induced pluripotent stem derived atrial cardiomyocytes (hiPSC-ACMs) were transfected with an adenovirus carrying the same mutation. We used enzyme linked immunosorbent assay (ELISA) to determine the AMPK activity in HL-1 cells and hiPSC-ACMs overexpressing -R302Q. Pathological results showed a large quantity of glycogen accumulation and vacuolization in cardiomyocytes from the proband atrial tissue. Western blot analysis revealed that the AMPK activity was significantly downregulated compared with that of the controls. Furthermore, remarkable glycogen deposition and impairment of AMPK activity were reproduced in HL-1 cells overexpressing -R302Q. Taken together, -R302Q mutation directly impair atrial cardiomyocytes. -R302Q mutation lead to glycogen deposition and promote the growth of atrial lesions by disrupting the AMPK pathway.
PRKAG2心肌病是一种罕见的进行性疾病，其特征为心室壁厚度增加和预激。5'-AMP激活蛋白激酶（AMPK）功能障碍在心室病变进展中起决定性作用。尽管携带-R302Q突变的患者房颤（AF）发生率很高，但导致该疾病的分子机制仍不清楚。我们对一个家族的三名患病成员进行了全基因组测序和连锁分析。从先证者手术干预中获取心房样本。对照心房活检样本取自持续性AF患者。使用苏木精和伊红（H&E）、Masson和过碘酸希夫（PAS）染色分析病理变化。通过蛋白质印迹法研究AMPK信号通路。用携带相同突变的腺病毒转染小鼠心房心肌细胞系（HL-1）和人诱导多能干细胞衍生的心房心肌细胞（hiPSC-ACMs）。我们使用酶联免疫吸附测定（ELISA）来测定过表达-R302Q的HL-1细胞和hiPSC-ACMs中的AMPK活性。病理结果显示先证者心房组织心肌细胞中有大量糖原积聚和空泡化。蛋白质印迹分析显示，与对照组相比，AMPK活性显著下调。此外，在过表达-R302Q的HL-1细胞中再现了明显的糖原沉积和AMPK活性受损。综上所述，-R302Q突变直接损害心房心肌细胞。-R302Q突变导致糖原沉积并通过破坏AMPK途径促进心房病变发展。
