The iPSC were then combined with specific heart tissue promoters to generate the desired cells. These cells were also labeled with green fluorescent protein (GFP) and firefly luciferase (a glowing laboratory reagent) to help with tracing cell migration and proliferation into the animal's system.
Researchers injected either the virus-mediated miR29b or a control material into the heart of the animal model and then experimentally induced a heart attack.
"These models allowed us to determine the possible benefits of miR29b and outcomes observed in two different control groups," Wang says.
Three days following the heart attack, researchers placed a cell patch on the damaged region and measured the expression of cardiac-related transcription factor A (a protein that binds to specific DNA sequences, controlling the movement of genetic information from DNA to mRNA), collagen levels in the damaged tissue and scar formation-related signaling pathways.
One month after the cell patch implantation, echocardiograms were performed to evaluate heart function.
"The mobilization of cells into the infarcted region of the heart was then analyzed by counting the number of GFP cells and by bioluminescence imaging (BLI) of cells with firefly luciferase, an imaging technology where the ongoing biological processes are visualized," Wang says.
Researchers found the number of GFP cells, BLI signals and heart function as a whole significantly increased in animals with the viral transfer that overexpressed miR-29b and were treated with the tri-cell patch.
"These findings show that an overexpression of miR-29 results in heart tissue changes that favor enhanced mobilization of desired cell types into infarct regions after heart attack, leading to improved heart function," he says. "Hopefully, one day such treatments will restore
|Contact: Katie Pence|
University of Cincinnati Academic Health Center