by Professor Anthony Mathur and Dr Sam Mohiddin, Barts and the London Hospital Trust
Most people will have read or heard about stem cells and the excitement they have generated in the medical research world.
But what are stem cells and why are they different from other cell types such as blood cells, brain cells and muscle cells?
Stem cells are unique because they have three special properties:
♥ They are unspecialised cells; this means that they have not developed into a mature cell type (specialised cell)
♥ Are capable of dividing and renewing themselves for long periods
♥ Under certain conditions, they can turn into specialised cell types. This process is called differentiation (see diagram)
Because of these abilities, stem cells represent a potential opportunity to treat chronic diseases such as heart failure. Stem cells may be able to divide into new specialised heart muscle cells that will help to repair damaged hearts. However, research is still required to understand the mechanism by which stem cells exert their benefit.
Adult bone marrow has been shown to be a source of progenitor/stem cells that can contribute to the repair of a variety of organs
Stem cell types and function
There are two types of stem cells: embryonic stem cells are obtained from an embryo; adult stem cells can be found in adult tissue. Adult stem cells are found in most organs.
Adult stem cells have been identified in many organs and tissues, including brain, bone marrow, blood vessels and heart muscle. Stem cells may remain quiescent (non-dividing) for long periods of time until they are activated by a normal need for more cells to maintain health, or to replace cells damaged by disease or injury.
In adult organisms, the main role of adult stem cells is to maintain and repair the tissue in which they are found. Typically, there are a very small number of stem cells in each tissue.
Scientists in many laboratories are trying to find better ways to grow large quantities of adult stem cells in cell culture and to manipulate them into the desired cell type so they can be used to treat injury or disease.
We hope that it may be possible to take stem cells from the bone marrow and implant them into the heart to promote significant repair and restoration of normal heart function.
Stem cells in heart disease
Animal and human trials involving stem cells in heart disease have not only demonstrated their safety, but have also shown promise. A new therapeutic option for the treatment of heart failure may be on the horizon.
More than 1,500 patients have been enrolled in stem cell trials worldwide. However most of the studies have involved patients with heart failure due to coronary artery disease (blood supply of the heart) and heart attacks.
Very few trials have involved patients with heart failure due to dilated cardiomyopathy (DCM).
UK trialBut a multi-centre trial of the effect of stem cell therapy in DCM, is now under way in the UK. We are already conducting two trials of adult bone marrow derived stem cell therapy in patients with heart disease. Our third study (for patients with dilated cardiomyopathy – Regenerate-DCM) is ready to start and is a collaboration between Barts and the London NHS Trust (the London Chest Hospital), The Heart Hospital (UCLH Foundation Trust) and the Royal Brompton Hospital.
The aim of the trial is to determine if stem cells from the patients’ own bone marrow can be used to improve the function of the heart and give symptom relief in idiopathic DCM.
We aim to include patients who are symptomatic (breathless), attending a heart failure clinic and on optimal heart failure treatment under supervision from their physician or heart failure nurse specialist. The use of the patient’s own adult stem cells would mean that the cells would not be rejected by the immune system. This represents a significant advantage.
For further information about the trial, contact: Laura Roberts, Department of Cardiology, London Chest Hospital, Bonner Road, London E2 9JX, e-mail:regenerate@bartsandthelondon.nhs.uk
Stem cell therapy is a new and exciting field in medicine. Research trials worldwide will provide us with a better understanding of this novel therapy.
We wish to acknowledge Dr Mills and Dr Arnous for their help in writing this article
We wish to acknowledge Dr Mills and Dr Arnous for their help in writing this article
Dedicated to Damian McLoughlin, who died age 20 of cardiomyopathy. This site is supported by Damian's family and friends.
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