Tag: apoliproteins

Categories : AgeingTags :

Two Key Proteins with a Major Role in Ageing

On By ModernMedia
Image by Mar Lezhava on Unsplash

In the largest genetic study of ageing to date, two key proteins have been identified that play a significant role in the ageing process. Developing drugs that target these proteins could be one way of slowing down ageing.

Genetics, lifestyle, environment and chance influence ageing. The study sheds light on the part proteins play in this process. Some people have higher or lower levels of certain proteins according to their individual DNA, which in turn affect a person’s health.

In a study published in Nature Aging, researchers from the University of Edinburgh combined the results of six large genetic studies into human ageing – each containing genetic information on hundreds of thousands of people.

Among 857 proteins studied, researchers identified two that had significant negative effects across various ageing measures.

People who inherited DNA that causes raised levels of these proteins were frailer, had poorer self-rated health and were less likely to live an exceptionally long life than those who did not.

The first protein, apolipoprotein(a) (LPA), is made in the liver and thought to play a role in clotting. High levels of LPA can increase the risk of atherosclerosis – a condition in which arteries become clogged with fatty substances. Heart disease and stroke is a possible outcome.

The second protein, vascular cell adhesion molecule 1 (VCAM1), is primarily found on the surfaces of endothelial cells lining blood vessels. The protein controls the vessels’ expansion and retraction – and have a function in blood clotting and the immune response.

Levels of VCAM1 increase in response to signals indicating an infection, and the protein then allows immune cells to cross the endothelial layer.

The researchers say that drugs used to treat diseases by reducing levels of LPA and VCAM1 could have the added benefit of improving quality and length of life.  

One such example is a clinical trial that is testing a drug to lower LPA as a way of reducing the risk of heart disease. No clinical trials with VCAM1 are underway, but studies in mice have shown how antibodies lowering this protein’s level improved cognition during old age.

The identification of these two key proteins could help extend the healthy years of life. Drugs that reduce these protein levels in the blood could allow the average person to live as healthy and as long as individuals who have won the genetic lottery and are born with genetically low LPA and VCAM1 levels.

Source: University of Edinburgh

Categories : Cardiovascular DiseaseTags :

New Easy Biomarker for Cardiovascular Risk

On By ModernMedia
Image by Landon Arnold on Unsplash

A large study has shown that apolipoproteins apoB and apoA-1 together provide early and reliable cardiovascular risk information as well as levels of low-density lipoprotein (LDL) cholesterol. The researchers advocate introducing new guidelines for detecting cardiac risk and say the results, published in PLOS Medicine, may pave the way for early treatment, which could help lower morbidity and mortality rates.

Cardiovascular disease is the most common cause of death globally and includes a wide range of conditions, such as stroke and myocardial infarction with atherosclerosis in different organs of the body. In many cases the disease can be prevented and arrested with lifestyle changes and lipid-lowering treatments using statins and other methods.

The cardiac risk assessment usually uses reference values for the LDL cholesterol. Other types of fat particles can also be measured along with apolipoproteins, which transport cholesterol in the blood. International guidelines for cardiovascular disease recommend using apolipoprotein apoB, which transports LDL cholesterol, as an alternative risk marker for people with type 2 diabetes, overweight and very high levels of blood lipids.

Recent research has, however, indicated the importance of also factoring in the apolipoprotein apoA-1, which transports the protective and anti-inflammatory HDL cholesterol. Calculating the apoB/apoA-1 ratio gives a risk quotient reflecting the balance between the fat particles that expedite atherosclerosis and the “good” protective apoA-1 particles that arrest the process.

In this present study, the researchers have analysed the link between cardiovascular disease and apoB/apoA-1 values in more than 137 000 Swedish adults between the ages of 25 and 84. The individuals were followed for 30 years, during which time 22 000 suffered some form of cardiovascular event. The analysis methods are simple, inexpensive and safe, and do not require pre-test fasting, as is the case with LDL and non-HDL tests. Basing their study on a large database, the researchers linked the laboratory analyses to several clinical diagnosis registers.

“The results show that the higher the apoB/apoA-1 value, the greater the risk of myocardial infarction, stroke and need for coronary surgery,” says Göran Walldius, senior author and professor emeritus at the Institute of Environmental Medicine, Unit of Epidemiology, Karolinska Institutet. “The study also showed that the risk was amplified in the presence of low protective levels of apoA-1.”

Individuals with the highest apoB/apoA-1 values had a 70% higher risk of severe cardiovascular disease and almost triple the risk of non-fatal myocardial infarction compared with those with the lowest apoB/apoA-1 values. Individuals with the highest risk quotient were also more affected by severe cardiovascular diseases many years earlier than individuals with the lowest apoB/apoA-1 values.

The relationship was observed in both men and women and the elevated levels could be detected as early as 20 years before the onset of cardiovascular disease.

“Early preventive treatment and information about cardiovascular risk is, of course, important in enabling individuals to manage their risk situation,” Walldius says. “Early treatment can also reduce the cost burden on the public health services.”

Taken together, the results suggest that the apoB/apoA-1 ratio is a better marker for identifying at-risk individuals for cardiovascular disease compared to the apoB method alone.

“It should be possible to introduce cut-values for apoB, apoA-1 and the apoB/apoA-1 ratio into new guidelines as a complement to current guidance on the detection and treatment of dyslipidaemia,” said Walldius.

Source: Karolinska Institutet