Lab-based experiments show that six specific recombinant proteins are capable of converting healthy skin cells, or any other type of human cell, into heart cells1,2.
These proteins can even facilitate the generation of new heart cells for patients who need heart surgery, say researchers at the Indian Institute of Technology Guwahati.
Human hearts cannot repair damaged tissues after a heart attack. To overcome this, scientists led by Rajkumar P. Thummer artificially synthesised gene sequences that encode six proteins - GATA4, MEF2C, TBX5, ETS2, MESP1 and HAND2. These proteins aid the growth of cardiac precursor cells and cardiac muscle cells. They transferred the gene sequences into the cells of Escherichia coli.
The gene sequences overexpressed the recombinant proteins in the bacterial cells. The researchers then isolated and purified the proteins, and studied their efficiency in permeating specific human cells.
The team, which included Krishna Kumar Haridhasapavalan and Pradeep Kumar Sundaravadivelu, found that the proteins entered the cells’ cytoplasm and eventually reached the nuclei. The HAND2 protein induced the migration of endothelial cells, which line all blood vessels and help to form new ones. This is essential for cell growth.
HAND2 and MEF2C were found to synergistically activate a marker specific to heart cells. These proteins help cardiomyocytes, the cells responsible for heart contractions, to mature.
These results show that the recombinant proteins are biologically active. The techniques to produce the proteins are simple, cost-effective and highly reproducible, the researchers note.