Friday 8 August 2014

Gene Therapy Experiment Creates Biological Pacemakers

Researchers at a heart institute in California have synthesised biological pacemakers that could potentially replace mechanical pacemaker implants for patients suffering from irregular heartbeats.



                                                                                                        

After nearly 12 years of research, a team of cardiologists at the Cedars-Sinai Heart Institute, LA, have managed to create "pacemaker" tissue from heart muscle cells in living pigs with heart arrhythmias. The success of the research contributes to a reinforcement in the larger field of somatic therapy - non-inherent genetic manipulation of vegetative cells (non-sex cells) in an organism. The Director of the Cardiogenetics-Familial Arrhythmia Clinic, Dr Eugenio Cingolani, believes the implications of this breakthrough are wide and could be very beneficial: 
      "It is possible that one day, we might be able to save lives by replacing hardware with an injection of genes."

The minimally-invasive experiment involved the insertion of a specific gene into the cardiac tissue of certain pigs with conditions that caused them to have very slow or irregular heart rates. The gene in question is the T Box 18 (TBX18), which is involved in the embryonic development of the heart. A catheter was used to access the heart tissue inside the test-subject pigs, and the gene was transfered through an artificial adenovirus - a basic, medium-sized, non-enveloped virus. The adenovirus would have been injected into the tissue and would have incorporated the TBX18 gene into the cardiac cells' DNA. A transformation would have taken place, changing the virus-infected cardiac tissue into a "pacemaker" for the heart, the Sino-atrial (SA) node. This new SA tissue would have begun to send out regular electrical signals, causing the hearts of the pigs to contract at a normal, healthy rate.

The 14 day study looked at the adenovirus-infected pigs alongside non-infected pigs with the same heart conditions. After the first day the transformed pigs were already observed to have stronger, faster heartbeats compared to the other pigs. The research is already being branded a huge success amongst scientific communities, and because the procedure is so minimally invasive scientists are looking at more complex applications. For example babies with congenital heartblock could be treated before they are even born, reducing the complications after birth.

The full scientific paper was published by Science Translational Medicine, and can be found on their website (Link below).








Sources:
  • LINK TO SCIENTIFIC PAPER http://stm.sciencemag.org/content/6/245/245ra94.abstract?sid=7b6dce60-bb1e-4dd3-99a0-c8716aa8854b
  • http://www.medicalnewstoday.com/articles/279760.php
  • http://www.bbc.co.uk/news/health-28325370
  • http://www.ncbi.nlm.nih.gov/gene/9096
  • Image of heart retrieved from  http://www.citruscardiology.org/arrhythmias.html