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Osteochondroprogenitor Cell
Osteochondroprogenitor cells are progenitor cells that arise from mesenchymal stem cells (MSC) in the bone marrow. They have the ability to differentiate into osteoblasts or chondrocytes depending on the signalling molecules they are exposed to, giving rise to either bone or cartilage respectively. Osteochondroprogenitor cells are important for bone formation and maintenance. Discovery Alexander Friedenstein and his colleagues first identified osteoprogenitor cells in multiple mammalian tissues, before any genetic or morphological criteria were put in place for bone marrow or connective tissues. Osteoprogenitor cells can be identified by their associations with existing bone or cartilage structures, or their placement in the embryo, as the sites for osteogenesis and chondrogenesis are now known. Cell signalling and differentiation Osteochondroprogenitor can be found between MSCs and the terminally differentiated osteoblasts and chondrocytes. Via different signalling molecules an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
MSC High Magnification
MSC may refer to: Computers * Message Sequence Chart * Microelectronics Support Centre of UK Rutherford Appleton Laboratory * MIDI Show Control * MSC Malaysia (formerly known as Multimedia Super Corridor) * USB mass storage device class (USB MSC) * Mobile Switching Center, of a phone network * Management saved console Corporations * Managed Service Company, a UK company structure * MSC Industrial Direct, formerly Manhattan Supply Company * MSC Software, simulation software company, formerly MacNeal-Schwendler Corporation * Metric Systems Corporation * Mediterranean Shipping Company Education * Master of Science, usually MSc or M.Sc. * Mastère en sciences, French degree * Memorial Student Center, Texas A&M University, US * Mesa State College * Mount Saint Charles Academy * Munsang College, Hong Kong * Marinduque State College, Philippines, now Marinduque State University Military * Medical Service Corps, of the US military forces * Military Sealift Command, US Navy * ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Endochondral Ossification
Endochondral ossification is one of the two essential processes during fetal development of the mammalian skeletal system by which bone tissue is produced. Unlike intramembranous ossification, the other process by which bone tissue is produced, cartilage is present during endochondral ossification. Endochondral ossification is also an essential process during the rudimentary formation of long bones, the growth of the length of long bones, and the natural healing of bone fractures. Growth of the cartilage model The cartilage model will grow in length by continuous cell division of chondrocytes, which is accompanied by further secretion of extracellular matrix. This is called interstitial growth. The process of appositional growth occurs when the cartilage model also grows in thickness due to the addition of more extracellular matrix on the peripheral cartilage surface, which is accompanied by new chondroblasts that develop from the perichondrium. Primary center of ossificatio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phosphoinositide 3-kinase
Phosphoinositide 3-kinases (PI3Ks), also called phosphatidylinositol 3-kinases, are a family of enzymes involved in cellular functions such as cell growth, proliferation, differentiation, motility, survival and intracellular trafficking, which in turn are involved in cancer. PI3Ks are a family of related intracellular signal transducer enzymes capable of phosphorylating the 3 position hydroxyl group of the inositol ring of phosphatidylinositol (PtdIns). The pathway, with oncogene PIK3CA and tumor suppressor gene PTEN, is implicated in the sensitivity of cancer tumors to insulin and IGF1, and in calorie restriction. Discovery The discovery of PI3Ks by Lewis Cantley and colleagues began with their identification of a previously unknown phosphoinositide kinase associated with the polyoma middle T protein. They observed unique substrate specificity and chromatographic properties of the products of the lipid kinase, leading to the discovery that this phosphoinositide kinase ha ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
PTEN (gene)
Phosphatase and tensin homolog (PTEN) is a phosphatase in humans and is encoded by the ''PTEN'' gene. Mutations of this gene are a step in the development of many cancers, specifically glioblastoma, lung cancer, breast cancer, and prostate cancer. Genes corresponding to PTEN ( orthologs) have been identified in most mammals for which complete genome data are available. ''PTEN'' acts as a tumor suppressor gene through the action of its phosphatase protein product. This phosphatase is involved in the regulation of the cell cycle, preventing cells from growing and dividing too rapidly. It is a target of many anticancer drugs. The protein encoded by this gene is a phosphatidylinositol-3,4,5-trisphosphate 3-phosphatase. It contains a tensin-like domain as well as a catalytic domain similar to that of the dual specificity protein tyrosine phosphatases. Unlike most of the protein tyrosine phosphatases, this protein preferentially dephosphorylates phosphoinositide substrates. It ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Selenoprotein
In molecular biology a selenoprotein is any protein that includes a selenocysteine (Sec, U, Se-Cys) amino acid residue. Among functionally characterized selenoproteins are five glutathione peroxidases (GPX) and three thioredoxin reductases, (TrxR/TXNRD) which both contain only one Sec. Selenoprotein P is the most common selenoprotein found in the plasma. It is unusual because in humans it contains 10 Sec residues, which are split into two domains, a longer N-terminal domain that contains 1 Sec, and a shorter C-terminal domain that contains 9 Sec. The longer N-terminal domain is likely an enzymatic domain, and the shorter C-terminal domain is likely a means of safely transporting the very reactive selenium atom throughout the body. Species distribution Selenoproteins exist in all major domains of life, eukaryotes, bacteria and archaea. Among eukaryotes, selenoproteins appear to be common in animals, but rare or absent in other phyla -one has been identified in the green alga '' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Selenium Deficiency
Selenium deficiency occurs when an organism lacks the required levels of selenium, a critical nutrient in many species. Deficiency, although relatively rare in healthy well-nourished individuals, can have significant negative results, affecting the health of the heart and the nervous system; contributing to depression, anxiety, and dementia; and interfering with reproduction and gestation. Signs and symptoms Selenium deficiency in combination with Coxsackievirus infection can lead to Keshan disease, which is potentially fatal. Selenium deficiency also contributes (along with iodine deficiency) to Kashin-Beck disease. The primary symptom of Keshan disease is myocardial necrosis, leading to weakening of the heart. Kashin-Beck disease results in atrophy, degeneration and necrosis of cartilage tissue. Keshan disease also makes the body more susceptible to illness caused by other nutritional, biochemical, or infectious diseases. Selenium is also necessary for the conversion of the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
SMAD (protein)
Smads (or SMADs) comprise a family of structurally similar proteins that are the main signal transducers for receptors of the transforming growth factor beta (TGF-B) superfamily, which are critically important for regulating cell development and growth. The abbreviation refers to the homologies to the ''Caenorhabditis elegans'' SMA ("small" worm phenotype) and MAD family ("Mothers Against Decapentaplegic") of genes in Drosophila. There are three distinct sub-types of Smads: receptor-regulated Smads ( R-Smads), common partner Smads (Co-Smads), and inhibitory Smads ( I-Smads). The eight members of the Smad family are divided among these three groups. Trimers of two receptor-regulated SMADs and one co-SMAD act as transcription factors that regulate the expression of certain genes. Sub-types The R-Smads consist of Smad1, Smad2, Smad3, Smad5 and Smad8/9, and are involved in direct signaling from the TGF-B receptor. Smad4 is the only known human Co-Smad, and has the role of partn ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cranial Neural Crest
The cranial neural crest is one of the four regions of the neural crest. The cranial neural crest arises in the anterior and populates the face and the pharyngeal arches giving rise to bones, cartilage, nerves and connective tissue. The endocranium and facial bones of the skull are ultimately derived from crest cells. :''Other Migration Locations:'' :*Into the pharyngeal arches and play an inductive role in thymus development. :*Into the pharyngeal arches and form the parafollicular cell or ultimobranchial bodies of the thyroid gland. :*Into the pharyngeal arches and play an inductive role in parathyroid gland development. :*Facial ectomesenchyme of the pharyngeal arches forming skeletal muscle, bone, and cartilage in the face. :*Odontoblasts (dentin-producing cells) of the teeth. :*Around the optic vesicle and the developing eye and contributes to many eye elements such the choroid, sclera, iris, and ciliary body. It also contributes to the attaching skeletal muscles of the eye. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cre-Lox Recombination
Cre-Lox recombination is a site-specific recombinase technology, used to carry out deletions, insertions, translocations and inversions at specific sites in the DNA of cells. It allows the DNA modification to be targeted to a specific cell type or be triggered by a specific external stimulus. It is implemented both in eukaryotic and prokaryotic systems. The Cre-lox recombination system has been particularly useful to help neuroscientists to study the brain in which complex cell types and neural circuits come together to generate cognition and behaviors. NIH Blueprint for Neuroscience Research has created several hundreds of Cre driver mouse lines which are currently used by the worldwide neuroscience community. The system consists of a single enzyme, Cre recombinase, that recombines a pair of short target sequences called the ''Lox'' sequences. This system can be implemented without inserting any extra supporting proteins or sequences. The Cre enzyme and the original ''Lox'' sit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gene Knockout
A gene knockout (abbreviation: KO) is a genetic technique in which one of an organism's genes is made inoperative ("knocked out" of the organism). However, KO can also refer to the gene that is knocked out or the organism that carries the gene knockout. Knockout organisms or simply knockouts are used to study gene function, usually by investigating the effect of gene loss. Researchers draw inferences from the difference between the knockout organism and normal individuals. The KO technique is essentially the opposite of a gene knock-in. Knocking out two genes simultaneously in an organism is known as a double knockout (DKO). Similarly the terms triple knockout (TKO) and quadruple knockouts (QKO) are used to describe three or four knocked out genes, respectively. However, one needs to distinguish between heterozygous and homozygous KOs. In the former, only one of two gene copies ( alleles) is knocked out, in the latter both are knocked out. Methods Knockouts are accomplished thr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
