Electrophysiological engineering of heart-derived cells with calcium-dependent potassium channels improves cell therapy efficacy for cardioprotection

We have shown that calcium-activated potassium (KCa)-channels regulate fundamental progenitor-cell functions, including proliferation, but their contribution to cell-therapy effectiveness is unknown. Here, we test the participation of KCa-channels in human heart explant-derived cell (EDC) physiology and therapeutic potential. TRAM34-sensitive KCa3.1-channels, encoded by the KCNN4 gene, are exclusively expressed in therapeutically bioactive EDC subfractions and maintain a strongly polarized resting potential; whereas therapeutically inert EDCs lack KCa3.1 channels and exhibit depolarized resting potentials. Somatic gene transfer of KCNN4 results in membrane hyperpolarization and increases intracellular [Ca2+], which boosts cell-proliferation and the production of pro-healing cytokines/nanoparticles. Intramyocardial injection of EDCs after KCNN4-gene overexpression markedly increases the salutary effects of EDCs on cardiac function, viable myocardium and peri-infarct neovascularization in a well-established murine model of ischemic cardiomyopathy. Thus, electrophysiological engineering provides a potentially valuable strategy to improve the therapeutic value of progenitor cells for cardioprotection and possibly other indications.


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We require information from authors about some types of materials, experimental systems and methods used in many studies. Here, indicate whether each material, system or method listed is relevant to your study. If you are not sure if a list item applies to your research, read the appropriate section before selecting a response. This study is powered to a primary endpoint of change in echocardiographic left ventricular ejection fraction (LVEF). The sample size will be powered to include a meaningful improvement in echocardiographic LVEF between 21 days post EDC injection. A magnitude of 6% absolute difference in LVEF is considered to be a clinically-relevant improvement in cardiac function after cell therapy. A standard deviation of 5% in the measurement of LVEF is assumed. Allowing for an alpha error of 0.05%, a sample size of 11 animals for each experimental arm will achieve a power of 80% (beta error<20%) to detect a clinically-relevant improvement in LVEF.
Data was excluded if the day 7 echocardiogram demonstrated an ejection fraction greater than 40% or less than 20%. Data was also exclude if the animal died prior to the experimental endpoint.
The echocardiogram was performed until satisfactory views were obtained.
A series of sealed envelopes were prepared that contained allocation to each treatment. Envelopes were evenly distributed throughout the surgery days. Four to eight surgeries were performed each day. Lab staff prepared 1-2 treatments of each type (e.g., KCNN4-EDCs, EV-EDCs, NT-EDCs or vehicle) per lab day. The animal surgeon opened the envelope and administered the treatment.
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8-9 week old male NOD/SCID IL2R! mice
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Atrial appendages were donated by patients undergoing clinically indicated heart surgery. Clinical characteristics are outlined in Supplementary Table 1.
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