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Damage-associated Molecular Pattern
Damage-associated molecular patterns (DAMPs) are molecules within cells that are a component of the innate immune response released from damaged or dying cells due to trauma or an infection by a pathogen. They are also known as danger signals, and alarmins because they serve as warning signs to alert the organism to any damage or infection to its cells. DAMPs are endogenous danger signals that are discharged to the extracellular space in response to damage to the cell from mechanical trauma or a pathogen. Once a DAMP is released from the cell, it promotes a noninfectious inflammatory response by binding to a pattern recognition receptor (PRR). Inflammation is a key aspect of the innate immune response; it is used to help mitigate future damage to the organism by removing harmful invaders from the affected area and start the healing process. As an example, the cytokine Cytokines () are a broad and loose category of small proteins (~5–25 kDa) important in cell signaling. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Innate Immune System
The innate immune system or nonspecific immune system is one of the two main immunity strategies in vertebrates (the other being the adaptive immune system). The innate immune system is an alternate defense strategy and is the dominant immune system response found in plants, fungi, prokaryotes, and invertebrates (see #Beyond vertebrates, Beyond vertebrates).. The major functions of the innate immune system are to: * recruit immune cells to infection sites by producing chemical factors, including chemical mediators called cytokines * activate the complement cascade to identify bacteria, activate cells, and promote clearance of immune complex, antibody complexes or dead cells * identify and remove foreign substances present in organs, tissues, blood and lymph, by specialized white blood cells * activate the adaptive immune system through antigen presentation * act as a physical and chemical barrier to infectious agents; via physical measures such as skin and mucus, and chemical me ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Granule (cell Biology)
In cell biology, a granule is a small particle barely visible by light microscopy. The term is most often used to describe a secretory vesicle containing important components of cell physiology. Examples of granules include granulocytes, platelet granules, insulin granules, germane granules, starch granules, and stress granules. It is considered as a cell organelle. Types There are mainly 2 types of granules based on presence or absence of membrane: # Membrane bound granules. # Non Membrane bound granules. Eosinophilic Granules, Basophilic Granules, Secretory Granules are examples of Membrane bound granules. P-granules, Stress granules are examples for Non Membrane bound granules. In leukocytes A group of leukocytes, called granulocytes, are white blood cells containing enzyme granules that play a significant role in the immune system. Granulocytes include neutrophils, eosinophils, and basophils which attack bacteria or parasites, and respond to allergens. Each type of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hyaluronan
Hyaluronic acid (; abbreviated HA; conjugate acid, conjugate base hyaluronate), also called hyaluronan, is an anion#Anions and cations, anionic, Sulfation, nonsulfated glycosaminoglycan distributed widely throughout connective tissue, connective, epithelial tissue, epithelial, and neural tissues. It is unique among glycosaminoglycans as it is non-sulfated, forms in the plasma membrane instead of the Golgi apparatus, and can be very large: human Synovial fluid, synovial HA averages about per molecule, or about 20,000 disaccharide monomers, while other sources mention . Medically, hyaluronic acid is used to treat osteoarthritis of the knee and dry eye, for wound repair, and as a cosmetic filler. The average 70 kg (150 lb) person has roughly 15 grams of hyaluronan in the body, one third of which is turned over (i.e., degraded and synthesized) per day. As one of the chief components of the extracellular matrix, it contributes significantly to cell proliferation and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
CD14
CD14 ( cluster of differentiation 14) is a human protein made mostly by macrophages as part of the innate immune system. It helps to detect bacteria in the body by binding lipopolysaccharide (LPS), a pathogen-associated molecular pattern (PAMP). CD14 exists in two forms, one anchored to the membrane by a glycosylphosphatidylinositol (GPI) tail (mCD14), the other a soluble form (sCD14). Soluble CD14 either appears after shedding of mCD14 (48 kDa) or is directly secreted from intracellular vesicles (56 kDa). The x-ray crystal structure of human CD14 reveals a monomeric, bent solenoid structure containing a hydrophobic amino-terminal pocket. CD14 was the first described pattern recognition receptor. Function CD14 acts as a co-receptor (along with the Toll-like receptor TLR 4 and MD-2) for the detection of bacterial lipopolysaccharide (LPS). CD14 can bind LPS only in the presence of lipopolysaccharide-binding protein (LBP). Although LPS is considered its main ligand, CD14 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
TLR6
Toll-like receptor 6 is a protein that in humans is encoded by the ''TLR6'' gene. TLR6 is a transmembrane protein, member of toll-like receptor family, which belongs to the pattern recognition receptor (PRR) family. TLR6 acts in a heterodimer form with toll-like receptor 2 (TLR2). Its ligands include multiple diacyl lipopeptides derived from gram-positive bacteria and mycoplasma and several fungal cell wall saccharides. After dimerizing with TLR2, the NF-κB intracellular signalling pathway is activated, leading to a pro-inflammatory cytokine production and activation of innate immune response. TLR6 has also been designated as CD286 (cluster of differentiation 286). Function The protein encoded by this gene is a member of the toll-like receptor (TLR) family which plays a fundamental role in pathogen recognition and activation of innate immunity. TLRs are highly conserved from Drosophila to humans and share structural and functional similarities. They recognize pathogen-associ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Versican
Versican is a large extracellular matrix proteoglycan that is present in a variety of human tissues. It is encoded by the ''VCAN'' gene. Versican is a large chondroitin sulfate proteoglycan with an apparent molecular mass of more than 1000kDa. In 1989, Zimmermann and Ruoslahti cloned and sequenced the core protein of fibroblast chondroitin sulfate proteoglycan. They designated it versican in recognition of its versatile modular structure. Versican belongs to the lectican protein family, with aggrecan (abundant in cartilage), brevican and neurocan (nervous system proteoglycans) as other members. Versican is also known as chondroitin sulfate proteoglycan core protein 2 or chondroitin sulfate proteoglycan 2 (CSPG2), and PG-M. Structure These proteoglycans share a homology (biology), homologous globular N-terminal, C-terminal, and glycosaminoglycan (GAG) binding regions. The N-terminal (G1) globular domain consists of Antibody, Ig-like loop and two link modules, and has Hyalur ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Decorin
Decorin is a protein that in humans is encoded by the ''DCN'' gene. Decorin is a proteoglycan that is on average 90 - 140 kilodaltons (kDa) in molecular weight. It belongs to the small leucine-rich proteoglycan (SLRP) family and consists of a protein core containing leucine repeats with a glycosaminoglycan (GAG) chain consisting of either chondroitin sulfate (CS) or dermatan sulfate (DS). Decorin is a small cellular or pericellular matrix proteoglycan and is closely related in structure to biglycan protein. Decorin and biglycan are thought to be the result of a gene duplication. This protein is a component of connective tissue, binds to type I collagen fibrils, and plays a role in matrix assembly. Naming Decorin's name is a derivative of both the fact that it "decorates" collagen type I, and that it interacts with the "d" and "e" bands of fibrils of this collagen. Function Decorin appears to influence fibrillogenesis, and also interacts with fibronectin, thrombospo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
NLRP3
NLR family pyrin domain containing 3 (NLRP3) (previously known as NACHT, LRR, and PYD domains-containing protein 3 [NALP3] and cryopyrin), is a protein that in humans is encoded by the ''NLRP3'' gene located on the long arm of chromosome 1. NLRP3 is expressed predominantly in macrophages and as a component of the inflammasome, detects products of damaged cells such as extracellular adenosine triphosphate, ATP and crystalline uric acid. Activated NLRP3 in turn triggers an immune response. Mutations in the NLRP3 gene are associated with a number of organ specific autoimmune diseases. Nomenclature NACHT, LRR, and PYD are respectively acronyms for: * NACHT domain, NACHT – NAIP (neuronal apoptosis inhibitor protein), C2TA [class 2 transcription activator, of the Major histocompatibility complex, MHC, HET-E (Podospora anserina#Heterokaryon incompatibility, heterokaryon incompatibility) and TP1 (telomerase-associated protein 1) * Leucine-rich repeat, LRR – "leucine-rich repeat" a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
TLR4
Toll-like receptor 4 (TLR4), also designated as CD284 (cluster of differentiation 284), is a key activator of the innate immune response and plays a central role in the fight against bacterial infections. TLR4 is a transmembrane protein of approximately 95 kDa that is encoded by the ''TLR4'' gene. TLR4 belongs to the toll-like receptor family which is representative of the pattern recognition receptors (PRR), so named for their ability to recognize evolutionarily conserved components of microorganisms (bacteria, viruses, fungi and parasites) called pathogen-associated molecular patterns (PAMPs). The recognition of a PAMP by a PRR triggers rapid activation of the innate immunity essential to fight infectious diseases. TLR4 is expressed in immune cells mainly of myeloid origin, including monocytes, macrophages and dendritic cells (DC). It is also expressed at a lower level on some non-immune cells, including epithelium, endothelium, placental cells and beta cells in Langerhans i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
TLR2
Toll-like receptor 2 also known as TLR2 is a protein that in humans is encoded by the ''TLR2'' gene. TLR2 has also been designated as CD282 (cluster of differentiation 282). TLR2 is one of the toll-like receptors and plays a role in the immune system. TLR2 is a membrane protein, a receptor, which is expressed on the surface of certain cells and recognizes foreign substances and passes on appropriate signals to the cells of the immune system. Function The protein encoded by this gene is a member of the toll-like receptor (TLR) family, which plays a fundamental role in pathogen recognition and activation of innate immunity. TLRs are highly conserved from ''Drosophila'' to humans and share structural and functional similarities. They recognize pathogen-associated molecular patterns (PAMPs) that are expressed on infectious agents, and mediate the production of cytokines necessary for the development of effective immunity. The various TLRs exhibit different patterns of expression. T ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Biglycan
Biglycan is a small leucine-rich repeat proteoglycan (SLRP) which is found in a variety of extracellular matrix tissues, including bone, cartilage and tendon. In humans, biglycan is encoded by the ''BGN'' gene which is located on the X chromosome. The name "biglycan" was proposed in an article by Fisher, Termine and Young in an article in the Journal of Biological Chemistry in 1989 because the proteoglycan contained two GAG chains; formerly it was known as proteoglycan-I (PG-I). Structure Biglycan consists of a protein core containing leucine-rich repeat regions and two glycosaminoglycan (GAG) chains consisting of either chondroitin sulfate (CS) or dermatan sulfate (DS), with DS being more abundant in most connective tissues. The CS/DS chains are attached at amino acids 5 and 10 in human biglycan. The composition of the GAG chains has been reported as varying according to tissue of origin. Non-glycanated forms of biglycan (no GAG chains) increase with age in human articular c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Extracellular Matrix
In biology, the extracellular matrix (ECM), also called intercellular matrix (ICM), is a network consisting of extracellular macromolecules and minerals, such as collagen, enzymes, glycoproteins and hydroxyapatite that provide structural and biochemical support to surrounding cells. Because multicellularity evolved independently in different multicellular lineages, the composition of ECM varies between multicellular structures; however, cell adhesion, cell-to-cell communication and differentiation are common functions of the ECM. The animal extracellular matrix includes the interstitial matrix and the basement membrane. Interstitial matrix is present between various animal cells (i.e., in the intercellular spaces). Gels of polysaccharides and fibrous proteins fill the interstitial space and act as a compression buffer against the stress placed on the ECM. Basement membranes are sheet-like depositions of ECM on which various epithelial cells rest. Each type of connective tissue ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
