Oxysterols

Oxysterols (from cholesterol , -ol) are bioactive compounds derived from steroids that have undergone oxidation. The basis of the structure of oxysterols is cholesterol .

In mammals, endogenous oxysterols (22 (R) -, 24 (S) -, 27-hydroxycholesterols, 24 (S) -, 25-epoxycholesterols, cholestenoic acid derivatives) are intermediate products in the synthesis of steroids and bile acids . Participate in numerous links in cell metabolism . ^[one]
The regulation of the biochemical functions of oxysterols is mediated by a system of nuclear LXR receptors (Liver X receptor), first detected in the liver . The LXRα chain gene is located on chromosome 11 (11p11.2) and the LXRβ gene is located on 19 (19q13.3).

Content

Role in Atherogenesis

Oxysterols play a key role in the pathogenesis of atherosclerosis . ^[2]
Autooxylation of cholesterol is possible during transport, in LDL , while predominantly 7-ketocholesterol ( lipid peroxidation ) is formed. The main reason for the oxidative resistance of LDL is considered tocopherols . ^[3] The pathochemical transformation of cholesterol into 25-, 27-hydroxycholesterols is possible directly in the atherosclerotic focus. Desialized and glycosylated forms of LDL are more susceptible to oxidation.

Oxysterol intake with food

For humans, the consumption of exogenous (atypical) oxysterols is very dangerous . The most significant compounds formed during the modification of cholesterol in the presence of oxygen: 7-ketocholesterol, 7α-, 7β-hydroxycholesterols, 5α-, 6α-, 5β-, 6β-epoxycholesterols. They are also formed during industrial frying, heat drying, and other types of heat treatment of foods rich in cholesterol in the air (for example, in the production of dried whole milk), in everyday life - when animal fats are used improperly (frying in butter , storage defects of cholesterol-rich foods). Alimentary sources of oxysterols include egg yolks, frozen meat products , fatty dairy products , and some types of frozen fish (cod, herring).

Clinical role

Nonsteroidal agonists of oxysterol receptors (in experiments: hypocholamide, T0901317, GW3965) are promising drugs in the treatment of atherosclerosis and some other related types of pathology.

Notes

↑ Carriers A.P. Sterols and their transport in the development of animals. // Ontogenesis 2008, T. 39, No. 3, p. 165-189. (unopened) (inaccessible link) . Date of treatment May 5, 2014. Archived on May 5, 2014.
↑ Sudakov N.P., Nikiforov S. B., Konstantinov Yu. M., Klimenkov I. V., Novikova M. A., Lepekhova S. A. The role of peroxide-modified lipoproteins in the mechanisms of development of mitochondrial vascular dysfunction during atherogenesis / / Bulletin of the VSNS SB RAMS. - 2008. - No. 4. - p. 85-89 Archived on May 5, 2014.
↑ Voivode M.I., Ragino Yu.I., Semaeva E.V., Kashtanova E.V., Ivanova M.V., Chernyavsky A.M., Nikitin Yu. P. Lipid blood spectrum and resistance to lipoprotein oxidation blood serum in patients with coronary atherosclerosis in Western Siberia. // Bulletin SB RAMS, 2003, No. 3, p. 47-51. (unopened) (inaccessible link) . Date of treatment May 5, 2014. Archived on May 5, 2014.

[1] Carriers A.P. Sterols and their transport in the development of animals. // Ontogenesis 2008, T. 39, No. 3, p. 165-189. (unopened) (inaccessible link) . Date of treatment May 5, 2014. Archived on May 5, 2014.

[2] Sudakov N.P., Nikiforov S. B., Konstantinov Yu. M., Klimenkov I. V., Novikova M. A., Lepekhova S. A. The role of peroxide-modified lipoproteins in the mechanisms of development of mitochondrial vascular dysfunction during atherogenesis / / Bulletin of the VSNS SB RAMS. - 2008. - No. 4. - p. 85-89 Archived on May 5, 2014.

[3] Voivode M.I., Ragino Yu.I., Semaeva E.V., Kashtanova E.V., Ivanova M.V., Chernyavsky A.M., Nikitin Yu. P. Lipid blood spectrum and resistance to lipoprotein oxidation blood serum in patients with coronary atherosclerosis in Western Siberia. // Bulletin SB RAMS, 2003, No. 3, p. 47-51. (unopened) (inaccessible link) . Date of treatment May 5, 2014. Archived on May 5, 2014.