BACKGROUND: Mutations in the lamin A/C gene (LMNA) may cause familial dilated 
cardiomyopathy (dilated cardiomyopathy) characterized by early onset 
atrio-ventricular block (A-V block) before the manifestation of dilated 
cardiomyopathy and high risk of sudden death due to ventricular arrhythmia, 
which is very similar to the phenotype of gap junction related heart disease. 
This study aimed to determine the expression and localization of connexins in 
neonatal myocytes transfected with wild-type (WT) or mutant LMNA to elucidate 
how these mutations cause heart diseases.
METHODS: We studied the connexin 43 (Cx43) and connexin 40 (Cx40) expression in 
cultured neonatal myocytes transfected with wild-type (WT) or mutant LMNA 
(Glu82Lys (E82K) and Arg644Cys (R644C)) using confocal imaging and Western 
blotting analysis.
RESULTS: Cx43 protein expression was reduced by 40% in cells transfected with 
LMNA E82K than that in cells transfected with WT LMNA cDNA. Confocal imaging 
showed that the Cx43 located inside the cells by LMNA E82K. By contrast, LMNA 
E82K mutation had no effect on expression and localization of Cx40. LMNA R644C 
transfection did not show any significant effects on gap junctions at all.
CONCLUSIONS: Our findings suggest that LMNA E82K significantly reduced the Cx43 
expression and altered its localization which may be one of the pathological 
mechanisms underlying LMNA-related heart disease.