I'm Giuseppe Poli,
from the Department of Clinical and Biological Sciences at the University of Torino, Italy.
The title of my talk today is Cholesterol Oxidation: between health and disease.
Cholesterol is an important lipid in our body,
and is a dynamic molecule because it has a very complex and important metabolism.
The metabolism of cholesterol is mainly oxidative,
and the products are both of enzymatic and of non-enzymatic origin.
The main oxysterols involved both in physiology
and in pathophysiology are reported in this picture in this slide.
Of the enzymatic origin,
the most important enzymes are 27-, 25-, 24-hydroxycholesterol,
and also 7-alpha-hydroxycholesterol plays some role.
On the other hand,
very importantly, by the way,
are also the oxysterols originated through non-enzymatic pathways,
the very toxic 7-ketocholesterol, and 5,6-epoxycholesterol.
It is interesting to underline the origin of the oxysterols present in plasma and tissues.
Oxysterols could derive from the diet.
They are already present in defined food,
particularly red meat and cheese,
and they are mainly produced through autoxidation of foodstuff-
the way of deterioration, or in any way autoxidation, of food.
The endogenous sources of oxysterols are also important,
both of non-enzymatic and of enzymatic origins, as I told you previously.
The non-enzymatic pathways involve mainly the reactive oxygen species.
These molecules oxidize cholesterol.
One of the most effective, let's say,
ubiquitous systems of non-enzymatic origin of oxysterols is represented by inflammation.
Inflammation, indeed, is always associated with a relatively high production of oxysterols.
As I outlined before,
what is important, especially in physiology,
are the pathways of enzymatic production of oxysterols.
But, for just a second,
let's focus on inflammation and the production of oxysterols.
It doesn't matter whether inflammation is coming first