Effects of TMEM43 on conduction velocity and sodium channel expression.

A. Electrograms recorded from adjacent MEA electrodes in HL-1 cell cultures. All cells beat spontaneously. Control and TMEM43-WT cells beat with a regular, synchronous rhythm. TMEM43-S358L cells beat with an irregular, comparatively slowed rhythm. B. Average velocity illustrating a decrease in conduction velocity of the TMEM43-S358L cells (1.2 cm/s) compared to control cells (2.5 cm/s) and TMEM43-WT cells (2.1 cm/s) (n = 7 control, n = 6 TMEM43-WT and n = 6 TMEM43-S358L, * p<0.01). All results are representative of six independent culture experiments. C. Western blot demonstrating expression of NaV1.5 in control, TMEM43-WT and TMEM43-S358L cells. GAPDH was used as a loading control. Rabbit polyclonal NaV1.5 antibody specifically detected sodium ion channel (NaV1.5) expression in all three cell types. Neither wild-type nor mutant TMEM43 altered the NaV1.5 expression. All results are representative of three independent Western blot experiments.

A. 从HL-1细胞培养物中相邻微电极阵列（MEA）电极记录的细胞电图。所有细胞均可自发搏动。对照组与TMEM43野生型（TMEM43-WT）细胞的搏动节律规整且同步；TMEM43-S358L突变型（TMEM43-S358L）细胞则表现为搏动节律紊乱，且搏动速度相对减慢。
B. 平均传导速度分析结果显示，与对照组（2.5 cm/s）及TMEM43-WT组（2.1 cm/s）相比，TMEM43-S358L组细胞的传导速度显著降低（1.2 cm/s）（对照组n=7，TMEM43-WT组n=6，TMEM43-S358L组n=6，*p<0.01）。所有结果均来自6次独立细胞培养实验。
C. 蛋白质免疫印迹（Western blot）实验结果显示，对照组、TMEM43-WT组与TMEM43-S358L组细胞中均检测到NaV1.5的表达。以甘油醛-3-磷酸脱氢酶（GAPDH）作为上样对照。兔源多克隆NaV1.5抗体可特异性识别三种细胞类型中的钠离子通道（NaV1.5）蛋白。野生型与突变型TMEM43均未改变NaV1.5的蛋白表达水平。所有结果均来自3次独立的蛋白质免疫印迹实验。