ObjectiveTo investigate the changes and mechanism of the cytoskeleton and polarity in cardiomyocyte-like cells derived from patients with left ventricular noncompaction (LVNC).  MethodsAfter induced pluripotent stem cells (iPSCs) were isolated from LVNC patients and normal individuals

respectively

the obtained cells were induced to differentiate into cardiomyocyte-like cells. Then transcriptome sequencing was performed. Transmission electron microscopy (TEM) was employed to observe the changes of the myocardial cytoskeleton. Immunofluorescence assay was used to detect the location and expression of cytoskeleton-associated proteins

fibrous actin (F-actin)

tubulin dimer (ɑ/β-tublin)

and polar protein Par6 and vinculin. Western blotting was used to detect the expression of Rho/Rock pathway key protein

Ras homolog gene family member A (RhoA).  ResultsBoth the obtained iPSCs derived from LVNC patients and normal persons positively expressed the surface molecular markers of embryonic stem cells

Oct4

Sox2

SSEA4

and TRA1-81

and could be induced into cardiomyocyte-like clusters with autonomous pulsating rhythm. Immunofluorescence assay indicated that the cardiomyocyte-like cells expressed the surface markers of cardiomyocytes

cTnT and ɑ-actinin. The results of transcriptome sequencing showed that there were multiple differential genes related closely to microtubules between the 2 kinds of cardiomyocyte-like cells. Compared with the cells derived from the normal individuals

there was a disordered arrangement of the cytoskeleton with TEM

significantly decreased expression levels of ɑ/β-tublin  (n=62

226.4±65.1

P<0.01

Z=－3.451)

F-actin (n=62，(236.4±33.2），P<0.001)

and vinculin (n=57

137.2±35.9)

P<0.001

Z=－3.852). and it was unevenly distributed and obviously concentrated in the cell membrane

and obviously up-regulation of Par6 (n=64

-132.7±43.5

P<0.01

Z=－3.148) with the aid of immunofluorescence assay. Western blotting demonstrated that the expression of RhoA was significantly increased in the cells derived from the patient group (P<0.01). ConclusionThe cytoskeleton and polarity of cardiomyocyte-like cells derived from LVNC patients are indeed abnormal.