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Preadipocytes
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 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] |
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] |
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] |
White Adipose Tissue
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 Adipocyte, adipocytes. In humans, the healthy body fat percentage, 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 Lipid droplet, 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 ... [...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] |
Adiponectin
Adiponectin (also referred to as GBP-28, apM1, AdipoQ and Acrp30) is a protein hormone and adipokine, which is involved in regulating glucose levels and fatty acid breakdown. In humans, it is encoded by the ''ADIPOQ'' gene and is produced primarily in adipose tissue, but also in muscle and even in the brain. Structure Adiponectin is a 244-amino-acid-long polypeptide (protein). It has four distinct regions: The first is a short signal sequence that targets the hormone for secretion outside the cell; next is a short region that varies between species; the third is a 65-amino acid region with similarity to collagenous proteins; the last is a globular domain. Overall, this protein shows similarity to the complement 1Q factors ( C1Q), but when the three-dimensional structure of the globular region was determined, a striking similarity to TNFα was observed, despite unrelated protein sequences. Function Adiponectin is a protein hormone that modulates a number of metabolic pro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Apelin
Apelin (also known as APLN) is a peptide that in humans is encoded by the ''APLN'' gene. Apelin is one of two endogenous ligands for the G-protein-coupled APJ receptor that is expressed at the surface of some cell types. It is widely expressed in various organs such as the heart, lung, kidney, liver, adipose tissue, gastrointestinal tract, brain, adrenal glands, endothelium, and human plasma. Discovery Apelin is a peptide hormone that was identified in 1998 by Masahiko Fujino and his colleagues at Gunma University and Takeda Pharmaceutical Company. In 2013, a second peptide hormone named Elabela was found by Bruno Reversade to also act as an endogenous ligand to the APLNR. Biosynthesis The apelin gene encodes a pre-proprotein of 77 amino acids, with a signal peptide in the N-terminal region. After translocation into the endoplasmic reticulum and cleavage of the signal peptide, the proprotein of 55 amino acids may generate several active fragments: a 36 amino acid pepti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Polyhedron
In geometry, a polyhedron (: polyhedra or polyhedrons; ) is a three-dimensional figure with flat polygonal Face (geometry), faces, straight Edge (geometry), edges and sharp corners or Vertex (geometry), vertices. The term "polyhedron" may refer either to a solid figure or to its boundary surface (mathematics), surface. The terms solid polyhedron and polyhedral surface are commonly used to distinguish the two concepts. Also, the term ''polyhedron'' is often used to refer implicitly to the whole structure (mathematics), structure formed by a solid polyhedron, its polyhedral surface, its faces, its edges, and its vertices. There are many definitions of polyhedron. Nevertheless, the polyhedron is typically understood as a generalization of a two-dimensional polygon and a three-dimensional specialization of a polytope, a more general concept in any number of dimensions. Polyhedra have several general characteristics that include the number of faces, topological classification by Eule ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cell (biology)
The cell is the basic structural and functional unit of all life, forms of life. Every cell consists of cytoplasm enclosed within a Cell membrane, membrane; many cells contain organelles, each with a specific function. The term comes from the Latin word meaning 'small room'. Most cells are only visible under a light microscope, microscope. Cells Abiogenesis, emerged on Earth about 4 billion years ago. All cells are capable of Self-replication, replication, protein synthesis, and cell motility, motility. Cells are broadly categorized into two types: eukaryotic cells, which possess a Cell nucleus, nucleus, and prokaryotic, prokaryotic cells, which lack a nucleus but have a nucleoid region. Prokaryotes are single-celled organisms such as bacteria, whereas eukaryotes can be either single-celled, such as amoebae, or multicellular organism, multicellular, such as some algae, plants, animals, and fungi. Eukaryotic cells contain organelles including Mitochondrion, mitochondria, which ... [...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] |
