Universal Theory of Atherosclerosis Pathogenesis

Abstract

The paper shows that atherosclerosis results from disturbed cholesterol homeostasis in the body, the development of systemic stromal-vascular lipid-protein dystrophy (or lipidosis, or cholesterolosis) complicated by extracellular focal lipid deposits with a predominant cholesterol in the interstitial tissue of the inner arterial and aortic layer. These deposits are foreign to this body tissue. They induce the development of chronic productive granulomatous inflammation in it – granulomatosis around endogenous foreign bodies. Cholesterol deposition is promoted by a positive cholesterol balance in the body; increased permeability of the endothelium in hemodynamically vulnerable parts of the arteries, where blood components, including LP, infiltrate their wall; a lack of hydrolytic enzymes in the cell lysosomes that could destroy the steroid nucleus of the cholesterol molecule. Being essential for each specific organism (for building membranes, the formation of bile acids, the synthesis of steroid hormones, vitamin D3), cholesterol, if exceeded, can increase the probability of developing atherosclerosis. Genetic mechanisms are implicated in the disturbed lipid protein metabolism in the human body. Hyperlipoproteinemias (HLPs) are known to be the most common metabolic disorders. The dystrophy under consideration results from primary HLP types IIa, IIb, III, IV, V, as well as secondary HLPs in patients with various medical conditions associated with an increase in blood LDL and / or VLDL and/or a decrease in HDL. A reduced cholesterol efflux from peripheral tissues due to a decreased HDL content and the development of lipidosis are seen in diabetes, obesity, physical inactivity, stress, puberty, menopause, hypertriglyceridemia, cigarette smoking, uremia, treatment with anabolic steroids, beta-adrenergic blocking agents, gestagens, and the use of contraceptives. The most pronounced manifestations of dystrophy are characteristic of HLP types IIA, IIb, III, but its moderate development complicated by atherosclerosis also occurs in types IV and V, which are accompanied by increased blood VLDL. Mutations of LDL receptor genes, apoprotein genes lead to the development of stromal vascular dystrophy and atherosclerosis. A number of rare genetic disorders of sterol metabolism accompany impaired metabolism of cholesterol and its esters: hepatic lipase deficiency (with accumulation of VLDL and IDLs); a deficiency in lysosomal hydrolase of cholesterol esters with impaired LDL metabolism (Wolman disease); cholesterol ester accumulation disease; cerebrotendinous xanthomatosis; cerebral cholesterolosis; Toichlander and Hand Schüler Christian syndromes. The main factor contributing to the development of inflammation in the inner vascular wall of arteries and aorta in atherosclerosis is the cyclic hydrocarbonic structure of cholesterol, which cannot be cleaved in the lysosomes of MPs. The leading role of the cyclic hydrocarbonic structure of cholesterol, which is insoluble and indestructible by MPs, in the induction of atherosclerosis-related inflammation is confirmed by the fact of the atherogenic action of cholesterol derivatives having its structure. An important factor in inflammatory morphogenesis is the lipoprotein dyscolloidosis occurring in the arterial intima and the physical and chemical metamorphosis of cholesterol. A colloidal solution, solid crystals of free cholesterol and liquid crystals of cholesterol esters have a pronounced phlogogenic and sclerogenic effect on the interstitial tissue of the arterial intima.