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Haptoglobin
Haptoglobin (abbreviated as Hp) is the protein that in humans is encoded by the ''HP'' gene. In blood plasma, haptoglobin binds with high affinity to ''free'' hemoglobin released from erythrocytes, and thereby inhibits its deleterious oxidative activity. Compared to Hp, hemopexin binds to ''free'' heme. The haptoglobin-hemoglobin complex will then be removed by the reticuloendothelial system (mostly the spleen). In clinical settings, the haptoglobin assay is used to screen for and monitor intravascular hemolytic anemia. In intravascular hemolysis, free hemoglobin will be released into circulation and hence haptoglobin will bind the hemoglobin. This causes a decline in haptoglobin levels. The protein was discovered as a "plasma substance" in 1938 by French biochemists Max-Fernand Jayle and Michel Polonovski. Function Hemoglobin that has been released into the blood plasma by damaged red blood cells has harmful effects. The ''HP'' gene encodes a preproprotein that is proc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hemopexin
Hemopexin (or haemopexin; Hpx; Hx), also known as beta-1B-glycoprotein, is a glycoprotein that in humans is encoded by the ''HPX'' gene and belongs to the hemopexin family of proteins. Hemopexin is the plasma protein with the highest binding affinity for heme. Hemoglobin ''itself'' circulating ''alone'' in the blood plasma (called ''free hemoglobin'', as opposed to the hemoglobin situated in and circulating with the red blood cell.) will soon be oxidized into met-hemoglobin which then further disassociates into ''free'' heme along with globin chain. The free heme will then be oxidized into free met-heme and sooner or later the hemopexin will come to bind free met-heme together, forming a complex of met-heme and hemopexin, continuing their journey in the circulation until reaching a receptor, such as LRP1, on hepatocytes or macrophages within the spleen, liver and bone marrow. Hemopexin's arrival and subsequent binding to the free heme not only prevent heme's pro-oxidant and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
CD163
CD163 (Cluster of Differentiation 163) is a protein that in humans is encoded by the CD163 gene. CD163 is the high affinity scavenger receptor for the hemoglobin- haptoglobin complex and in the absence of haptoglobin - with lower affinity - for hemoglobin alone. It also is a marker of cells from the monocyte/macrophage lineage. CD163 functions as innate immune sensor for gram-positive and gram-negative bacteria. The receptor was discovered in 1987. Structure The molecular size is 130 kDa. The receptor belongs to the scavenger receptor cysteine rich family type B and consists of a 1048 amino acid residues extracellular domain, a single transmembrane segment and a cytoplasmic tail with several splice variants. Clinical significance A soluble form of the receptor exists in plasma, and cerebrospinal fluid., commonly denoted sCD163. It is generated by ectodomain shedding of the membrane bound receptor, which may represent a form of modulation of CD163 function. sCD163 sheddin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Free Hemoglobin
Intravascular hemolysis describes hemolysis that happens mainly inside the vasculature. As a result, the contents of the red blood cell are released into the general circulation, leading to hemoglobinemia and increasing the risk of ensuing hyperbilirubinemia. __TOC__ Mechanism Intravascular hemolysis is the state when the red blood cell ruptures as a result of the complex of complement autoantibodies attached (fixed) on the surfaces of RBCs attack and rupture RBCs' membranes, or a parasite such as Babesia exits the cell that ruptures the RBC's membrane as it goes. Upon RBC's rupture, components of which are released and circulating in the blood plasma. These components comprise hemoglobin and others. At this stage, the hemoglobin is called free hemoglobin. Free hemoglobin (also called naked hemoglobin) is the un-bound hemoglobin that is not enclosed in the red blood cell. The naked hemoglobin is devoid of its anti-oxidant sentries that are normally available within the RBC. Free h ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cytokine
Cytokines () are a broad and loose category of small proteins (~5–25 kDa) important in cell signaling. Cytokines are produced by a broad range of cells, including immune cells like macrophages, B cell, B lymphocytes, T cell, T lymphocytes and mast cells, as well as Endothelium, endothelial cells, fibroblasts, and various stromal cells; a given cytokine may be produced by more than one type of cell. Due to their size, cytokines cannot cross the lipid bilayer of cells to enter the cytoplasm and therefore typically exert their functions by interacting with specific cytokine receptor, cytokine receptors on the target cell surface. Cytokines are especially important in the immune system; cytokines modulate the balance between humoral immunity, humoral and cell-mediated immunity, cell-based immune responses, and they regulate the maturation, growth, and responsiveness of particular cell populations. Some cytokines enhance or inhibit the action of other cytokines in complex way ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Toll-like Receptor 4
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 isle ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
NF-κB
Nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) is a family of transcription factor protein complexes that controls transcription (genetics), transcription of DNA, cytokine production and cell survival. NF-κB is found in almost all animal cell types and is involved in cellular responses to stimuli such as stress, cytokines, free radicals, heavy metals, ultraviolet irradiation, oxidized LDL, and bacterial or viral antigens. NF-κB plays a key role in regulating the immune response to infection. Incorrect regulation of NF-κB has been linked to cancer, inflammatory and autoimmune diseases, septic shock, viral infection, and improper immune development. NF-κB has also been implicated in processes of synaptic plasticity and memory. Discovery NF-κB was discovered by Ranjan Sen in the lab of Nobel laureate David Baltimore via its interaction with an 11-base pair sequence in the immunoglobulin light-chain Enhancer (genetics), enhancer in B cells. Later work ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hepatic Cells
Hepatic stellate cells (HSC), also known as perisinusoidal cells or Ito cells (earlier ''lipocytes'' or ''fat-storing cells''), are pericytes found in the perisinusoidal space of the liver, also known as the space of Disse (a small area between the Liver sinusoid, sinusoids and hepatocytes). The stellate cell is the major cell type involved in liver fibrosis, which is the formation of scar, scar tissue in response to liver damage; in addition these cells store and concentrate vitamin A. Structure Hepatic stellate cells can be selectively stained with Sodium gold chloride, gold chloride, but their distinguishing feature in routine histological preparations is the presence of multiple lipid droplets in their cytoplasm. Cytoglobin expression has been shown to be a specific marker with which hepatic stellate cells can be distinguished from portal myofibroblasts in the damaged human liver. In murine (rats, mice) liver, reelin expressed by Ito cells has been shown to be a reliable marke ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Skin
Skin is the layer of usually soft, flexible outer tissue covering the body of a vertebrate animal, with three main functions: protection, regulation, and sensation. Other animal coverings, such as the arthropod exoskeleton, have different developmental origin, structure and chemical composition. The adjective cutaneous means "of the skin" (from Latin ''cutis'' 'skin'). In mammals, the skin is an organ of the integumentary system made up of multiple layers of ectodermal tissue and guards the underlying muscles, bones, ligaments, and internal organs. Skin of a different nature exists in amphibians, reptiles, and birds. Skin (including cutaneous and subcutaneous tissues) plays crucial roles in formation, structure, and function of extraskeletal apparatus such as horns of bovids (e.g., cattle) and rhinos, cervids' antlers, giraffids' ossicones, armadillos' osteoderm, and os penis/ os clitoris. All mammals have some hair on their skin, even marine mammals like whales, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lung
The lungs are the primary Organ (biology), organs of the respiratory system in many animals, including humans. In mammals and most other tetrapods, two lungs are located near the Vertebral column, backbone on either side of the heart. Their function in the respiratory system is to extract oxygen from the atmosphere and transfer it into the bloodstream, and to release carbon dioxide from the bloodstream into the atmosphere, in a process of gas exchange. Respiration is driven by different muscular systems in different species. Mammals, reptiles and birds use their musculoskeletal systems to support and foster breathing. In early tetrapods, air was driven into the lungs by the pharyngeal muscles via buccal pumping, a mechanism still seen in amphibians. In humans, the primary muscle that drives breathing is the Thoracic diaphragm, diaphragm. The lungs also provide airflow that makes Animal communication#Auditory, vocalisation including speech possible. Humans have two lungs, a ri ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
