World Journal of Case Reports and Clinical Images
Scientists in Japan have developed a credible heart cell model for
arrhythmogenic cardiomyopathy and observed a positive response in the condition
using PKP2 gene therapy.
Arrhythmogenic
cardiomyopathy (ACM) is an inherited heart muscle disorder that is thought to
affect one in 5,000 and can cause sudden cardiac arrest, particularly in
children and athletes. Previous studies have established that defects in the
PKP2 gene, which encodes the protein plakophilin-2, play a pathological role in
the condition but, until now, such research has only been carried out on cells
derived from healthy patients.
In this new study, researchers from Osaka University successfully
developed heart cells from patients with the condition and observed that they
fail to contract correctly when grown in the laboratory. They observed that in
replacing the mutated PKP2 gene responsible for this effect, with an intact
copy, this defect is fixed.
The cells with
two mutated copies of PKP2 clearly exhibited reduced contractility and impaired
desmosome assembly due to plakophilin-2 deficiency, explains Shuichiro Higo, senior author. These effects were also observed
in cells with only one mutated copy of PKP2, although they were less severe.
Replacing the
mutated PKP2 with an intact copy of the gene repaired the defects in both cell
contraction and desmosome assembly, which the researchers were able to observe
using a time-lapse approach and fluorescently labelled desmosomes.
These findings
suggest that our cardiomyocyte cell lines recapitulate the pathology of
arrhythmogenic cardiomyopathy and provide a rapid and convenient platform for
developing gene-based therapies for this disease, says Higo.
This study was
published in Stem Cell Reports.