Dr Andrew Owens
Reader in Cardiothoracic Surgery

  • Email: a.owens@ncl.ac.uk
  • Telephone: 0191 241 8662
  • Fax: 0191 241 8666
  • Address: Institute of Genetic Medicine
    Newcastle upon Tyne
    Centre for Life
    Central Parkway
    Newcastle upon Tyne
    NE1 3BZ

Roles and Responsibilities

Reader in Cardiac Surgery, Institute of Genetic Medicine, Newcastle University. 

Honorary Consultant Cardiothoracic Surgeon, South Tees Hospitals NHS Foundation Trust.

Director of Research and Development,  South Tees Hospitals NHS Foundation Trust.

Chairman, Research Approval Board, South Tees Hospitals NHS Foundation Trust.


The identification of native cardiac stem cells and their role in development and disease.

Until recently the adult mammalian heart was considered to be a post-mitotic organ, lacking native stem cells and incapable of self-repair.  This view is being increasingly challenged, and a number of groups have isolated populations of putative cardiac stem cells, identified by the expression of antigenic surface markers associated with other known stem cells (notably Sca-1 and c-kit), variably characterising them by clonogenicity, mulitpotency and/or expression of cardiac-specific markers.  Despite increasing acceptance of the existence of such a population the differing descriptions, particularly the variable patterns of surface markers used, has led to dispute.

Telomerase is an enzyme that maintains the ends of telomeres in dividing cells, protecting them from long-term senescence and is only expressed in stem cells, adult male germline cells or tumours.  Telomerase reverse transcriptase (tert) regulates its function in stem cells.  In collaboration with Dr David Breault at Harvard University and Dr Nick Hole in Durham University, we developed a transgenic model that uses tert to drive the expression of green fluorescent protein (GFP).  We are using this model to test the hypothesis that native cardiac stem cells can be identified by telomerase expression, thereby identifying them using a functional, rather than antigenic, marker.

Characterisation studies demonstrated GFP expression identifying three recognised stem cell populations - male germ cells, haematopoietic stem cells and intestinal stem cells – and that the telomerase activity co-localised with the GFP-expressing cells.  Evaluation of the heart revealed a GFP-expressing population of cells that did not express haematopoietic markers and represented 0.02% of the cells derived.  The majority (80%) of the cells did not express either the Sca-1 or c-kit antigens, the remainder expressed one or both, thereby including most of the populations otherwise described.

The numbers of tert expressing cells present in the heart appears to decrease with age and very few are found in the adult mammalian heart, but we have observed the appearance of increased numbers in the heart muscle surrounding areas of damage or at times of increased growth.  We are now exploring their role in myocardial disease and regeneration.