Heart Research UK Research HighlightS
Dr David Bell and Prof Barbara McDermott, Queen’s University Belfast, £15,275
Protective effects of ‘adrenomedullin’ on the heart
Patients with high blood pressure or an injury to the heart caused a by lack of blood supply often develop an enlargement of the heart muscle which progresses to heart failure. The body has, however, means to counteract harmful processes and there is much interest in how such ‘cardioprotective’ systems work. One of these concerns adrenomedullin (AM), is a small protein made by the heart and blood vessels which is found at high levels in the blood of patients with cardiovascular disease.
As AM is a protein, it would have to be administered by frequent injections rather than by tablet form. One way to overcome this problem is to deliver a source of the gene which codes for AM, encapsulated in a virus. Following a single intravenous injection, the gene could be switched on, resulting in large amounts of AM being produced over a prolonged period.
This interesting gene therapy project showed in laboratory studies that the human AM gene could be effectively delivered to the heart using viral technology. Also, the researchers found that AM produced had direct beneficial effects on the heart muscle. In the future, these findings may provide the basis for small pilot clinical studies to assess the feasibility of delivering the AM gene to patients and whether this can reduce the overall cardiovascular risk in patients with high blood pressure.
Dr Kathy Triantafilou, University of Sussex, £54,255
Is infection linked with atherosclerosis?
Atherosclerosis, the build-up of fatty deposits on the inside walls of the arteries, underlies the majority of cardiovascular diseases. Atherosclerosis is a complex condition which is not completely understood but recent evidence shows that ongoing inflammatory processes play a part. The factors which initiate these processes have not been clearly identified but potential triggers may be high blood levels of cholesterol or bacterial pathogens such as Chlamydia pneumonia or Porphyromonas gingivalis.
This project focused on possible triggers of the inflammation involved in atherosclerosis and the role of particular receptors which help the immune system to recognise pathogens. The results showed that exposure of cells which line the blood vessels to high levels of low density lipoprotein (LDL cholesterol) followed by bacterial products, amplified the inflammatory response. This is the first reported evidence that high cholesterol levels and bacterial infection may act in synergy to trigger processes responsible for the formation of atherosclerotic plaques.
These interesting findings help to further our understanding of the chronic inflammation involved in atherosclerosis which in the future may lead to new ways of treating the condition. The next step is to study whether this interaction is observed in experiments which more closely mimic the real-life physiological situation.
Dr Douglas McGown, RCGP grant, £9,996
Blood pressure monitoring using mobile phone technology
High blood pressure, or ‘hypertension’, usually causes no symptoms, so often goes undiagnosed. However, hypertension is one of several risk factors that can increase the chance of developing heart disease, a stroke, and other serious conditions. Therefore, it is vital that high blood pressure is reduced to minimise the risk of developing cardiovascular disease in the future.
This HRUK grant to the Royal College of General Practitioners has enabled researchers to look at the attitudes of GPs, practice nurses and patients to a new technology for monitoring blood pressure at home. The innovative device stores and transmits data to the clinician via a Bluetooth-enabled mobile phone via the internet.
Using questionnaires and focus groups, the research showed that there was a clear positive attitude in the majority of patients and professionals towards using this technology. The researchers now recommend carrying out a clinical trial to assess the cost versus benefit of this form of blood pressure monitoring.
Dr Neeraj Chauhan, University of Bedfordshire, £79,322
Effects of statins on heart muscle cells
Statins lower the blood levels of cholesterol thereby helping to prevent coronary heart disease, but recently it has become clear that this is not the only way that they work. This project focused on the effects of statins on heart muscle cells which has been overlooked so far. The aim was to study the effects of the most commonly-prescribed statin, simvastatin, on the function of isolated heart muscle cells paying special attention to the caveolae. These are cholesterol-enriched pockets in the cell membrane which play a part in the control of function of the cardiac cells.
This work showed that simvastatin treatment depleted the caveolae of their two essential components and also reduced the numbers of caveloae in the cell membranes. The team also looked at the consequences of this on the heart muscle cells, revealing that statins may improve cardiac function through this pathway.
This is the first reported evidence that statins have beneficial effects on heart muscle cells and raises the possibility that these drugs may have a clinical use in the treatment of heart failure. The next step is to study whether this interaction is observed in experiments which more closely mimic the real-life physiological situation.
Dr Harpal Randeva, University of Warwick, £45,670
Protective effects of ‘orexins’ on the heart
Diabetes and obesity have increased disproportionately over the last decade, leading to a higher incidence of cardiovascular disease. Two hormones called orexin A and orexin B are known to be involved in the eating response and may have pivotal roles in the relationship between obesity and heart disease.
This research team investigated the effects of orexins on the heart in a laboratory model. Important and novel findings from this study show that pre-treatment with orexin B or a compound which mimics its effects (an agonist), protected the heart muscle from damage due to a lack of blood supply. These exciting findings suggest that orexins may have clinical potential in benefiting patients with angina or if used immediately following a heart attack. However, more research needs to be done to explore this ‘cardioprotective’ action further.
