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Adipocytes
Adipocytes, also known as lipocytes and fat cells, are the cells that primarily compose adipose tissue, specialized in storing energy as fat. Adipocytes are derived from mesenchymal stem cells which give rise to adipocytes through adipogenesis. In cell culture, adipocyte progenitors can also form osteoblasts, myocytes and other cell types. There are two types of adipose tissue, white adipose tissue (WAT) and brown adipose tissue (BAT), which are also known as white and brown fat, respectively, and comprise two types of fat cells. Structure White fat cells White fat cells contain a single large lipid droplet surrounded by a layer of cytoplasm, and are known as unilocular. The nucleus is flattened and pushed to the periphery. A typical fat cell is 0.1 mm in diameter with some being twice that size, and others half that size. However, these numerical estimates of fat cell size depend largely on the measurement method and the location of the adipose tissue. The fat stored ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Marrow Adipose Tissue
Bone marrow adipose tissue (BMAT), sometimes referred to as marrow adipose tissue (MAT), is a type of fat deposit in bone marrow. It increases in states of low bone density, such as osteoporosis, anorexia nervosa/ caloric restriction, skeletal unweighting such as that which occurs in space travel, and anti-diabetes therapies. BMAT decreases in anaemia, leukaemia, and hypertensive heart failure; in response to hormones such as oestrogen, leptin, and growth hormone; with exercise-induced weight loss or bariatric surgery; in response to chronic cold exposure; and in response to pharmacological agents such as bisphosphonates, teriparatide, and metformin. Anatomy Bone marrow adipocytes (BMAds) originate from mesenchymal stem cell (MSC) progenitors that also give rise to osteoblasts, among other cell types. Thus, it is thought that BMAT results from preferential MSC differentiation into the adipocyte, rather than osteoblast, lineage in the setting of osteoporosis. Since BMAT is ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Adipogenesis
Adipogenesis is the formation of adipocytes (fat cells) from stem cells. It involves 2 phases, determination, and terminal differentiation. Determination is mesenchymal stem cells committing to the adipocyte precursor cells, also known as lipoblasts or preadipocytes which lose the potential to differentiate to other types of cells such as chondrocytes, myocytes, and osteoblasts. Terminal differentiation is that preadipocytes differentiate into mature adipocytes. Adipocytes can arise either from preadipocytes resident in adipose tissue, or from bone-marrow derived progenitor cells that migrate to adipose tissue. Introduction Adipocytes play a vital role in energy homeostasis and process the largest energy reserve as triglycerol in the body of animals. Adipocytes stay in a dynamic state, they start expanding when the energy intake is higher than the expenditure and undergo mobilization when the energy expenditure exceeds the intake. This process is highly regulated by counter reg ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Adipose Tissue
Adipose tissue (also known as body fat or simply fat) is a loose connective tissue composed mostly of adipocytes. It also contains the stromal vascular fraction (SVF) of cells including preadipocytes, fibroblasts, Blood vessel, vascular endothelial cells and a variety of White blood cell, immune cells such as adipose tissue macrophages. Its main role is to store energy in the form of lipids, although it also cushions and Thermal insulation, insulates the body. Previously treated as being hormonally inert, in recent years adipose tissue has been recognized as a major endocrine organ, as it produces hormones such as leptin, estrogen, resistin, and cytokines (especially TNF-alpha, TNFα). In obesity, adipose tissue is implicated in the chronic release of pro-inflammatory markers known as adipokines, which are responsible for the development of metabolic syndromea constellation of diseases including type 2 diabetes, cardiovascular disease and atherosclerosis. Adipose tissue is d ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Leptin
Leptin (from Ancient Greek, Greek λεπτός ''leptos'', "thin" or "light" or "small"), also known as obese protein, is a protein hormone predominantly made by adipocytes (cells of adipose tissue). Its primary role is likely to regulate long-term Energy homeostasis, energy balance. As one of the major signals of energy status, leptin levels influence appetite, Hunger (physiology), satiety, and motivated behaviors oriented toward the maintenance of energy reserves (e.g., feeding, foraging behaviors). The amount of circulating leptin correlates with the amount of energy reserves, mainly Triglyceride, triglycerides stored in adipose tissue. High leptin levels are interpreted by the brain that energy reserves are high, whereas low leptin levels indicate that energy reserves are low, in the process adapting the organism to Starvation response, starvation through a variety of metabolic, endocrine, neurobiochemical, and behavioral changes. Leptin is coded for by the ''LEP'' gene ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Brown Adipose Tissue
Brown adipose tissue (BAT) or brown fat makes up the adipose organ together with white adipose tissue (or white fat). Brown adipose tissue is found in almost all mammals. Classification of brown fat refers to two distinct cell populations with similar functions. The first shares a common embryological origin with muscle cells, found in larger "classic" deposits. The second develops from white adipocytes that are stimulated by the sympathetic nervous system. These adipocytes are found interspersed in white adipose tissue and are also named 'beige' or 'brite' (for "brown in white"). Brown adipose tissue is especially abundant in newborns and in hibernation, hibernating mammals. It is also present and metabolically active in adult humans, but its prevalence decreases as humans age. Its primary function is thermoregulation. In addition to heat produced by shivering muscle, brown adipose tissue produces heat by non-shivering thermogenesis. The therapeutic targeting of brown fat for the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Resistin
Resistin, also known as adipose tissue-specific secretory factor (ADSF) or C/EBP-epsilon-regulated myeloid-specific secreted cysteine-rich protein (XCP1), is a cysteine-rich peptide hormone that is derived from adipose tissue and, in humans, is encoded by the ''RETN'' gene. In primates, pigs, and dogs, resistin is secreted primarily by immune and epithelial cells, whereas in rodents, it is mainly secreted by adipose tissue. The human resistin pre-peptide consists of 108 amino acid residues, while in mice and rats it is 114 amino acids in length; the molecular weight is approximately 12.5 kDa. Resistin is classified as an adipose-derived hormone (similar to a cytokine), and its physiological role has been widely debated, particularly regarding its involvement in obesity and type II diabetes mellitus ( T2DM). Discovery Resistin was discovered in 2001 and identified as a hormone produced by adipose tissue, with a role in promoting insulin resistance. Elevated resistin levels ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Brown Adipose Tissue
Brown adipose tissue (BAT) or brown fat makes up the adipose organ together with white adipose tissue (or white fat). Brown adipose tissue is found in almost all mammals. Classification of brown fat refers to two distinct cell populations with similar functions. The first shares a common embryological origin with muscle cells, found in larger "classic" deposits. The second develops from white adipocytes that are stimulated by the sympathetic nervous system. These adipocytes are found interspersed in white adipose tissue and are also named 'beige' or 'brite' (for "brown in white"). Brown adipose tissue is especially abundant in newborns and in hibernation, hibernating mammals. It is also present and metabolically active in adult humans, but its prevalence decreases as humans age. Its primary function is thermoregulation. In addition to heat produced by shivering muscle, brown adipose tissue produces heat by non-shivering thermogenesis. The therapeutic targeting of brown fat for the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
X-ray Microtomography
In radiography, X-ray microtomography uses X-rays to create cross-sections of a physical object that can be used to recreate a virtual model (3D model) without destroying the original object. It is similar to tomography and X-ray computed tomography. The prefix ''micro-'' (symbol: μ) is used to indicate that the pixel sizes of the cross-sections are in the micrometre range. These pixel sizes have also resulted in creation of its synonyms high-resolution X-ray tomography, micro-computed tomography (micro-CT or μCT), and similar terms. Sometimes the terms high-resolution computed tomography (HRCT) and micro-CT are differentiated, but in other cases the term high-resolution micro-CT is used. Virtually all tomography today is computed tomography. Micro-CT has applications both in medical imaging and in industrial computed tomography. In general, there are two types of scanner setups. In one setup, the X-ray source and detector are typically stationary during the scan while the s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Osmium
Osmium () is a chemical element; it has Symbol (chemistry), symbol Os and atomic number 76. It is a hard, brittle, bluish-white transition metal in the platinum group that is found as a Abundance of elements in Earth's crust, trace element in alloys, mostly in platinum ores. Osmium is the densest naturally occurring element. When experimentally measured using X-ray crystallography, it has a density of . Manufacturers use its alloys with platinum, iridium, and other platinum-group metals to make fountain pen Nib (pen)#Nib tipping, nib tipping, electrical contacts, and in other applications that require extreme durability and hardness. Osmium is among the Abundance of elements in Earth's crust, rarest elements in the Earth's crust, making up only 50 parts per trillion (Parts-per notation#Parts-per expressions, ppt). Characteristics Physical properties Osmium is a hard, brittle, blue-gray metal, and the densest stable element—about twice as dense as lead. The density of os ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mitochondria
A mitochondrion () is an organelle found in the cells of most eukaryotes, such as animals, plants and fungi. Mitochondria have a double membrane structure and use aerobic respiration to generate adenosine triphosphate (ATP), which is used throughout the cell as a source of chemical energy. They were discovered by Albert von Kölliker in 1857 in the voluntary muscles of insects. The term ''mitochondrion'', meaning a thread-like granule, was coined by Carl Benda in 1898. The mitochondrion is popularly nicknamed the "powerhouse of the cell", a phrase popularized by Philip Siekevitz in a 1957 ''Scientific American'' article of the same name. Some cells in some multicellular organisms lack mitochondria (for example, mature mammalian red blood cells). The multicellular animal '' Henneguya salminicola'' is known to have retained mitochondrion-related organelles despite a complete loss of their mitochondrial genome. A large number of unicellular organisms, such as microspo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lipid
Lipids are a broad group of organic compounds which include fats, waxes, sterols, fat-soluble vitamins (such as vitamins A, D, E and K), monoglycerides, diglycerides, phospholipids, and others. The functions of lipids include storing energy, signaling, and acting as structural components of cell membranes. Lipids have applications in the cosmetic and food industries, and in nanotechnology. Lipids are broadly defined as hydrophobic or amphiphilic small molecules; the amphiphilic nature of some lipids allows them to form structures such as vesicles, multilamellar/ unilamellar liposomes, or membranes in an aqueous environment. Biological lipids originate entirely or in part from two distinct types of biochemical subunits or "building-blocks": ketoacyl and isoprene groups. Using this approach, lipids may be divided into eight categories: fatty acyls, glycerolipids, glycerophospholipids, sphingolipids, saccharolipids, and polyketides (derived from condensatio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
White Fat
White adipose tissue or white fat is one of the two types of adipose tissue found in mammals. The other kind is brown adipose tissue. White adipose tissue is composed of monolocular adipocytes. In humans, the healthy amount of white adipose tissue varies with age, but composes between 6–25% of body weight in adult men and 14–35% in adult women. Its cells contain a single large fat droplet, which forces the nucleus to be squeezed into a thin rim at the periphery. They have receptors for insulin, sex hormones, norepinephrine, and glucocorticoids. White adipose tissue is used for energy storage. Upon release of insulin from the pancreas, white adipose cells' insulin receptors cause a dephosphorylation cascade that leads to the inactivation of hormone-sensitive lipase. It was previously thought that upon release of glucagon from the pancreas, glucagon receptors cause a phosphorylation cascade that activates hormone-sensitive lipase, causing the breakdown of the stored fat to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
