A cholesterol crystal is a solid, crystalline form of cholesterol found in gallstones and atherosclerosis. Gallstones occurring in industrialized societies typically contain more than 70-90% cholesterol by weight, much of which is crystalline. [1] Cholesterol crystals are a hallmark of atherosclerosis, which is believed to be an early cause of atherosclerotic inflammation. [2] Cholesterol phase transition from liquid to crystalline form is linked to inflammation. [3] Cholesterol crystals are believed to induce inflammation by activation of the NLRP3 inflammasome. [4] [5]
In addition to being a source of inflammation, cholesterol crystals are believed to cause mechanical injury by tearing tissue, causing plaque rupture. [6] Impaired removal of cholesterol crystals from demyelinated nerves by macrophages is believed to be associated with multiple sclerosis, and this remyelination failure is particularly impaired in the elderly. [7] [8]
Coronary artery disease (CAD), also called coronary heart disease (CHD), ischemic heart disease (IHD), myocardial ischemia, or simply heart disease, involves the reduction of blood flow to the cardiac muscle due to build-up of atherosclerotic plaque in the arteries of the heart. It is the most common of the cardiovascular diseases. Types include stable angina, unstable angina, and myocardial infarction.
Atherosclerosis is a pattern of the disease arteriosclerosis, characterized by development of abnormalities called lesions in walls of arteries. These lesions may lead to narrowing of the arterial walls due to buildup of atheromatous plaques. At onset there are usually no symptoms, but if they develop, symptoms generally begin around middle age. In severe cases, it can result in coronary artery disease, stroke, peripheral artery disease, or kidney disorders, depending on which body part(s) the affected arteries are located in the body.
Coronary thrombosis is defined as the formation of a blood clot inside a blood vessel of the heart. This blood clot may then restrict blood flow within the heart, leading to heart tissue damage, or a myocardial infarction, also known as a heart attack.
A vulnerable plaque is a kind of atheromatous plaque – a collection of white blood cells and lipids in the wall of an artery – that is particularly unstable and prone to produce sudden major problems such as a heart attack or stroke.
Paul M. Ridker is a cardiovascular epidemiologist and biomedical researcher. He is currently the Eugene Braunwald Professor of Medicine at Harvard University and Brigham and Women's Hospital, where he directs the Center for Cardiovascular Disease Prevention. Ridker also holds an appointment as Professor in the Department of Epidemiology at the Harvard T.H. Chan School of Public Health.
Interleukin-1 beta (IL-1β) also known as leukocytic pyrogen, leukocytic endogenous mediator, mononuclear cell factor, lymphocyte activating factor and other names, is a cytokine protein that in humans is encoded by the IL1B gene. There are two genes for interleukin-1 (IL-1): IL-1 alpha and IL-1 beta. IL-1β precursor is cleaved by cytosolic caspase 1 to form mature IL-1β.
Caspase-1/Interleukin-1 converting enzyme (ICE) is an evolutionarily conserved enzyme that proteolytically cleaves other proteins, such as the precursors of the inflammatory cytokines interleukin 1β and interleukin 18 as well as the pyroptosis inducer Gasdermin D, into active mature peptides. It plays a central role in cell immunity as an inflammatory response initiator. Once activated through formation of an inflammasome complex, it initiates a proinflammatory response through the cleavage and thus activation of the two inflammatory cytokines, interleukin 1β (IL-1β) and interleukin 18 (IL-18) as well as pyroptosis, a programmed lytic cell death pathway, through cleavage of Gasdermin D. The two inflammatory cytokines activated by Caspase-1 are excreted from the cell to further induce the inflammatory response in neighboring cells.
Muckle–Wells syndrome (MWS) is a rare autosomal dominant disease which causes sensorineural deafness and recurrent hives, and can lead to amyloidosis. Individuals with MWS often have episodic fever, chills, and joint pain. As a result, MWS is considered a type of periodic fever syndrome. MWS is caused by a defect in the CIAS1 gene which creates the protein cryopyrin. MWS is closely related to two other syndromes, familial cold urticaria and neonatal onset multisystem inflammatory disease—in fact, all three are related to mutations in the same gene and subsumed under the term cryopyrin-associated periodic syndromes (CAPS).
NLR family pyrin domain containing 3 (NLRP3), is a protein that in humans is encoded by the NLRP3 gene located on the long arm of chromosome 1.
Pyroptosis is a highly inflammatory form of lytic programmed cell death that occurs most frequently upon infection with intracellular pathogens and is likely to form part of the antimicrobial response. This process promotes the rapid clearance of various bacterial, viral, fungal and protozoan infections by removing intracellular replication niches and enhancing the host's defensive responses. Pyroptosis can take place in immune cells and is also reported to occur in keratinocytes and some epithelial cells.
Inflammasomes are cytosolic multiprotein complexes of the innate immune system responsible for the activation of inflammatory responses and cell death. They are formed as a result of specific cytosolic pattern recognition receptors (PRRs) sensing microbe-derived pathogen-associated molecular patterns (PAMPs), damage-associated molecular patterns (DAMPs) from the host cell, or homeostatic disruptions. Activation and assembly of the inflammasome promotes the activation of caspase-1, which then proteolytically cleaves pro-inflammatory cytokines, interleukin 1β (IL-1β) and interleukin 18 (IL-18), as well as the pore-forming molecule gasdermin D (GSDMD). The N-terminal GSDMD fragment resulting from this cleavage induces a pro-inflammatory form of programmed cell death distinct from apoptosis, referred to as pyroptosis, which is responsible for the release of mature cytokines. Additionally, inflammasomes can act as integral components of larger cell death-inducing complexes called PANoptosomes, which drive another distinct form of pro-inflammatory cell death called PANoptosis.
A myocardial infarction (MI), commonly known as a heart attack, occurs when blood flow decreases or stops in one of the coronary arteries of the heart, causing infarction to the heart muscle. The most common symptom is retrosternal chest pain or discomfort that classically radiates to the left shoulder, arm, or jaw. The pain may occasionally feel like heartburn.
Cryopyrin-associated periodic syndrome (CAPS) is a group of rare, heterogeneous autoinflammatory disease characterized by interleukin 1β-mediated systemic inflammation and clinical symptoms involving skin, joints, central nervous system, and eyes. It encompasses a spectrum of three clinically overlapping autoinflammatory syndromes including familial cold autoinflammatory syndrome, the Muckle–Wells syndrome (MWS), and neonatal-onset multisystem inflammatory disease that were originally thought to be distinct entities, but in fact share a single genetic mutation and pathogenic pathway, and keratoendotheliitis fugax hereditaria in which the autoinflammatory symptoms affect only the anterior segment of the eye.
Remnant cholesterol, also known as remnant lipoprotein, is a very atherogenic lipoprotein composed primarily of very low-density lipoprotein (VLDL) and intermediate-density lipoprotein (IDL). Stated another way, remnant cholesterol is all plasma cholesterol that is not LDL cholesterol or HDL cholesterol, which are triglyceride-poor lipoproteins. However, remnant cholesterol is primarily chylomicron and VLDL, and each remnant particle contains about 40 times more cholesterol than LDL.
Inflammaging is a chronic, sterile, low-grade inflammation that develops with advanced age, in the absence of overt infection, and may contribute to clinical manifestations of other age-related pathologies. Inflammaging is thought to be caused by a loss of control over systemic inflammation resulting in chronic overstimulation of the innate immune system. Inflammaging is a significant risk factor in mortality and morbidity in aged individuals.
Dr. George S. Abela is a clinician scientist, Professor of Medicine and Chief of the Cardiology Division at Michigan State University.
Nehal N. Mehta, is an American cardiologist at the National Heart, Lung, and Blood Institute (NHLBI) in Bethesda, Maryland where he studies the role of innate immunity and inflammation in the development of cardiovascular and metabolic diseases.
Crystallopathy is a harmful state or disease associated with the formation and aggregation of crystals in tissues or cavities, or in other words, a heterogeneous group of diseases caused by intrinsic or environmental microparticles or crystals, promoting tissue inflammation and scarring.
Dapansutrile (OLT1177) is an inhibitor of the NLRP3 inflammasome.
Kathryn J. Moore is a Canadian-born American cell biologist who is the Jean and David Blechman Professor of Cardiology and the founding director of the Cardiovascular Research Center at the New York University Grossman School of Medicine. Moore's research considers the pathogenesis of atherosclerosis, with a focus on the identification of novel therapeutic targets. She was elected Fellow of the National Academy of Sciences in 2021.