Why Kovid-19 patients with diabetes or heart disease are more likely to die: the virus leaches on cholesterol molecules to gain access to cells, study suggests
- Researchers study the role of cholesterol in coronavirus infection
- The presence of high cholesterol was found to be associated with increased infection of cells.
- Coronovirus is believed to bind cholesterol and lift it to the cell surface
- Once here it can then readily bind to ACE2, the receptor that allows the virus into human cells.
Cholesterol can help infect human cells by revealing coronovirus as a taxi service, new laboratory studies.
The findings may suggest that people with metabolic conditions such as diabetes and heart disease, who often have elevated cholesterol levels, form an proportionally higher proportion of patients who develop severe Kovid-19 symptoms.
Researchers found that SARS-CoV-2, the virus that causes Kovid-19, can stick to cholesterol molecules because they call their regular cell receptor SR-B1.
This helps position the pathogen so that its spike protein binds to the ACE2 receptor, which allows it to infect the cell.
This graphic shows how cholesterol can be abducted by SARS-CoV-2 to aid infection of human cells. The virus binds cholesterol and when the cholesterol then attaches its SR-B1 receptor to the surface of human cells, it carries the virus with it, which lets it latch on to ACE2 allowing it to infect the cells. is
A study published in Nature Metabolism by researchers from the Chinese Academy of Military Medical Sciences looked at the role of ‘good’ cholesterol in coronovirus infection, otherwise known as high-density lipoprotein (HDL).
The study specifically looked at the SR-B1 receptor, which combines with cholesterol molecules and is found on cells throughout the human body, including the lungs, where coronoviruses are targeted.
SARS-CoV-2 cannot directly exploit this receptor, the study found, but it can take advantage of the cholesterol-associated process of SR-B1 to infiltrate cells.
The viral spike on coronovirus – the same as that applied to ACE2 – consists of two segments, subunit one and subunit 2.
In their experiments, Chinese scientists found that the subunit can bind to a cholesterol. This means that when cholesterol naturally goes into its receptor, it also brings the coronavirus to the cell surface.
The researchers said that it ‘enhances viral regeneration’ and facilitates the entry of the cholesterol receptor ‘SARS-CoV-2 into ACE2-expressing cells by increasing virus attachment.’
The coronavirus uses the ACE2 receptor to infect cells, but it can latch on to cholesterol and use it as a cab to help attach it to ACE2 (stock)
What is ‘good’ cholesterol?
‘Good’ cholesterol is otherwise known as high density lipoprotein (HDL).
Cholesterol is a waxy substance found throughout the body and performs many useful functions, including helping to make your body cells.
It is linked to protein through your blood. These proteins are called lipoproteins.
Low-density cholesterol is one that can cause blockages and blockages cause sin to form blood vessels, causing stroke and heart attack.
But high-density can get rid of these and improve health.
In most people, high levels of high-density cholesterol are good for health.
However, in people with metabolic conditions such as diabetes and heart disease, it is regularly seen that they also have elevated levels because the body fails to regulate levels properly.
Researchers then discovered that by blocking SR-B1 and neutralizing it, it prevents infection.
They state that targeting the SR-B1 receptor may be a potential opportunity for future therapies.
The researchers reported in their paper, ‘The results of our study suggest that SR-B1 SARS-CoV-2 facilitates cellular attachment, penetration and infection.
‘Thus … SR-B1 may represent a therapeutic target to limit SARS-CoV-2 infection.’
This will likely benefit people with specific comorbidities compared to others. People with heart disease and diabetes, who increase HDL levels the most, are among those who would benefit the most.
“Heart disease and diabetes are associated with an increased risk of severe COVID-19,” the researchers write.
‘Nearly half of COVID-19 patients have chronic underlying diseases, mainly cardiovascular and brain diseases and diabetes.
‘In addition, increased COVID-19 mortality has been observed in patients with obesity or diabetes.’
NHS data from April show that approximately one-third (29 percent) of coronovirus patients had heart disease and about a fifth (19 percent) were diabetic.
A previous study by the NHS and Imperial College found that patients with type 2 diabetes die twice as many as Kovid-19 and the number of people who die from type 1 diabetes is three and a half times more.