New concept
RUDN biochemists have changed the concept of the body's defense system against atherosclerosis
Biochemists of the RUDN (and five other Moscow institutes, see the list of authors of the article – VM) have reviewed the role of high-density lipoproteins, which transport cholesterol, in the development of cardiovascular diseases. According to scientists, these compounds can not only have a medical effect, but also serve for drug delivery.
The results are published in the International Journal of Molecular Sciences (Kudinov et al., High-Density Lipoproteins as Homeostatic Nanoparticles of Blood Plasma).
Lipoproteins are high–molecular complexes based on protein molecules in combination with fatty acids. They participate in lipid, or fat, metabolism: for example, high-density lipoproteins in blood plasma transport cholesterol from body tissues to the liver. In the late 1970s and early 1980s, scientists noticed that these compounds promote the absorption of cholesterol from cell membranes. Thus, they prevent the appearance of atherosclerotic plaques and can protect against cardiovascular diseases. In animals – from fish to monkeys – in which high-density lipoproteins predominate in the blood plasma, atherosclerosis is rare. This led to the consolidation of the idea that HDL reduces cholesterol and therefore protects against diseases. But further study of these compounds showed that their functions are more multifaceted. They can regulate inflammatory processes, vasoconstriction and dilation of blood vessels and thrombosis, exhibit antioxidant properties, participate in immune reactions and communication of different types of cells. Russian biochemists have summarized the latest scientific data to reconsider the role of high-density lipoproteins in the human body.
"Historically, it was believed that high HDL levels are associated with low cholesterol in the blood, which protects against heart and vascular diseases. However, therapy based on raising the level of HDL was ineffective. New data have shown that it is the composition and structure of high-density lipoproteins that plays an important role, since dysfunctional molecules cannot do their job. It's time to abandon outdated traditional views and adopt a new concept of HDL," Olga Alekseeva, an employee of the Institute of Biochemical Technology and Nanotechnology of the RUDN.
Modern scientific data suggest that HDL have diverse functions. They can regulate inflammatory processes, vasoconstriction and dilation of blood vessels and thrombosis, exhibit antioxidant properties, participate in immune reactions and communication of different types of cells. In addition, they change their structure after interacting with various enzymes and tissues.
The biochemists of the RUDN became interested in how HDL could appear in the process of evolution. Apparently, these compounds play an important evolutionary role and they should be considered an ancient and dynamic platform designed to maintain homeostasis – the constancy of the internal environment of the body.
Recent studies have also shown that high–density lipoproteins affect the transport of microRNAs - small non-coding molecules that inhibit the synthesis of proteins from certain genes. All these features make HDL promising medical molecules that can deliver medicinal compounds to the exact place in the body, which is critically important, for example, in gene therapy. In addition, some of them themselves may have medicinal properties, the researchers from the RUDN together with their Russian colleagues concluded.
"High–density lipoproteins are complex natural nanoparticles that can be rearranged during interaction with cells and compounds. Even the presence of some proteins in their composition may not be permanent, but necessary for a certain process in the body. The data accumulated on this topic opens up opportunities for a deeper understanding of the pathogenesis of various diseases, intercellular interactions and immune response. Based on these natural nanoparticles, it is possible to create a new class of biomimetic drugs that will protect against these pathologies or fight them," says Alekseeva, an employee of the Institute of Biochemical Technology and Nanotechnology of the RUDN.
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