When 'Good' Cholesterol Goes Bad - Science Daily Article

http://www.sciencedaily.com/releases...0822110600.htm
Commentary and isolated quotes
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WE don't actually know much about the details of "cholesterol" - or more
technically correct, we don't actually know much about the details of
lipoproteins - composition and structure.

Article Quote:

"HDL, which removes cholesterol from artery walls, is also suspected of
having anti-inflammatory and antioxidant properties. Its evil twin, low
density lipoprotein cholesterol (LDL) deposits cholesterol in arteries.
To further explore HDL's role in the body, Heinecke and colleagues
conducted a detailed analysis of the protein composition of HDL and
found 48 proteins, including 22 proteins that play a role in cholesterol
metabolism and 13 proteins not previously known to exist in HDL."

WOW. 48 proteins involved in the structure of HDL, 13 of which were not
previously known to exist in HDL......

Article Quote:

"Scientists long have suspected that there may be dysfunctional forms of
so-called 'good' cholesterol, also called high density lipoprotein (HDL)
cholesterol, that can loose their heart-protective effect. But the exact
chemical composition of HDL, both good forms and bad, has remained
largely unknown, researchers say."



It will be wonderful, some future day, when the medical community
actually knows what lipoproteins are, and what can go wrong with them.

Someday, we may actually know what we are talking about with these big
words like LIPOPROTEINS. But, it may be a while.



"Targeting HDL could represent a new horizon in heart disease diagnosis
and treatment," says study leader Jay Heinecke, M.D., of the University
of Washington School of Medicine in Seattle. "But simply boosting HDL
levels may not be enough to prevent heart disease. You might have to
target the right proteins in HDL."

"....Indeed, a major pharmaceutical company recently withdrew an
experimental HDL-boosting drug when it was found that the drug caused an
increase in deaths and heart problems, Heinecke notes."




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Source: American Chemical Society
Date: August 22, 2007

Why Bad Things Can Happen To The Heart When 'Good' Cholesterol Goes Bad

Science Daily — It's yet another example of how a good thing can go bad:
Researchers have found evidence in laboratory studies that 'good'
cholesterol, renowned for its ability to protect against heart disease,
can undergo detrimental changes in protein composition that make it
'bad' for the heart.

Scientists long have suspected that there may be dysfunctional forms of
so-called 'good' cholesterol, also called high density lipoprotein (HDL)
cholesterol, that can loose their heart-protective effect. But the exact
chemical composition of HDL, both good forms and bad, has remained
largely unknown, researchers say.

In a study recently presented at the 234th national meeting of the
American Chemical Society, researchers reported what is believed to be
the most detailed analysis to date of the protein composition of HDL.
They uncovered surprising new information about HDL, including
previously unrecognized proteins that appear to play an important role
in maintaining heart health. Their findings could one day lead to new,
more accurate lab tests for heart disease as well as new, potentially
life-saving treatments for the disease, which is the number one killer
in the United States and other developed countries.

"Targeting HDL could represent a new horizon in heart disease diagnosis
and treatment," says study leader Jay Heinecke, M.D., of the University
of Washington School of Medicine in Seattle. "But simply boosting HDL
levels may not be enough to prevent heart disease. You might have to
target the right proteins in HDL."

HDL, which removes cholesterol from artery walls, is also suspected of
having anti-inflammatory and antioxidant properties. Its evil twin, low
density lipoprotein cholesterol (LDL) deposits cholesterol in arteries.
To further explore HDL's role in the body, Heinecke and colleagues
conducted a detailed analysis of the protein composition of HDL and
found 48 proteins, including 22 proteins that play a role in cholesterol
metabolism and 13 proteins not previously known to exist in HDL.

Of the proteins identified in HDL, some might play a previously
unsuspected role in preventing atherosclerotic plaques from rupturing.
The rupture of these plaques, followed by formation of an
artery-plugging blood clot, causes most heart attacks, the researcher
says. Other important protective proteins identified in HDL may protect
heart cells from injury during a heart attack, Heinecke says.

But other components found in HDL have potentially destructive effects
in the body by promoting cholesterol accumulation and inhibiting some of
the heart-protective effects of other proteins, Heinecke says. Thus,
boosting HDL cholesterol levels alone might not protect the heart, he
says. Indeed, a major pharmaceutical company recently withdrew an
experimental HDL-boosting drug when it was found that the drug caused an
increase in deaths and heart problems, Heinecke notes.

A better understanding of the protein components of HDL could therefore
lead to new, more accurate tests for predicting or evaluating heart
disease, says Heinecke, whose study is funded by the National Institutes
of Health. He notes that heart attacks can occur in people whose
cholesterol levels appear normal and that conventional diagnostic tests
for cholesterol levels do not always give a clear picture of the
disease. More effective, targeted HDL-based interventions could
potentially save lives, especially when used in combination with statin
drugs that target low density lipoproteins (LDL), or bad cholesterol,
says Heinecke, who notes that more studies are needed.

"There's still a lot we don't know about heart disease," Heinecke says.
"HDL is still a big mystery, but we're closing in on it and we're pretty
excited." Important interventions for fighting heart disease include
exercise, a well-balanced diet, and taking heart medications as
prescribed, experts say.