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Sphingosine-1-phosphate
Sphingosine-1-phosphate (S1P) is a signaling sphingolipid, also known as lysosphingolipid. It is also referred to as a bioactive lipid mediator. Sphingolipids at large form a class of lipids characterized by a particular aliphatic aminoalcohol, which is sphingosine. Production S1P is formed from ceramide, which is composed of a sphingosine and a fatty acid. Ceramidase, an enzyme primarily present in plasma membrane, will convert ceramide to sphingosine. sphingosine is then phosphorylated by sphingosine kinase (SK) isoenzymes. There are two identified isoenzymes, SK1 and SK2. These two enzymes have different tissue distribution. SK1 is highly expressed in spleen, lung and leukocytes, while SK2 is highly expressed in liver and kidney. SK2 is located mainly in the mitochondria, nucleus and the endoplasmic reticulum whereas SK1 is mainly located in cytoplasm and the cell membrane. Metabolism and degradation S1P can be dephosphorylated to sphingosine by sphingosine phosphatases and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sphingosine-1-phosphate Receptor
The sphingosine-1-phosphate receptors are a class of G protein-coupled receptors that are targets of the lipid signalling molecule Sphingosine-1-phosphate (S1P). They are divided into five subtypes: S1PR1, S1PR2, S1PR3, S1PR4 and S1PR5. Discovery In 1990, S1PR1 was the first member of the S1P receptor family to be cloned from endothelial cells. Later, S1PR2 and S1PR3 were cloned from rat brain and a human genomic library respectively. Finally, S1P4 and S1PR5 were cloned from in vitro differentiated human dendritic cells and rat cDNA library. Function The sphingosine-1-phosphate receptors regulate fundamental biological processes such as cell proliferation, angiogenesis, migration, cytoskeleton organization, endothelial cell chemotaxis, immune cell trafficking and mitogenesis. Sphingosine-1-phosphate receptors are also involved in immune-modulation and directly involved in suppression of innate immune responses from T cells. Subtypes Sphingosine-1-phosphate (S1P) receptors ar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sphingosine-1-phosphate Receptor
The sphingosine-1-phosphate receptors are a class of G protein-coupled receptors that are targets of the lipid signalling molecule Sphingosine-1-phosphate (S1P). They are divided into five subtypes: S1PR1, S1PR2, S1PR3, S1PR4 and S1PR5. Discovery In 1990, S1PR1 was the first member of the S1P receptor family to be cloned from endothelial cells. Later, S1PR2 and S1PR3 were cloned from rat brain and a human genomic library respectively. Finally, S1P4 and S1PR5 were cloned from in vitro differentiated human dendritic cells and rat cDNA library. Function The sphingosine-1-phosphate receptors regulate fundamental biological processes such as cell proliferation, angiogenesis, migration, cytoskeleton organization, endothelial cell chemotaxis, immune cell trafficking and mitogenesis. Sphingosine-1-phosphate receptors are also involved in immune-modulation and directly involved in suppression of innate immune responses from T cells. Subtypes Sphingosine-1-phosphate (S1P) receptors ar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lysophospholipid Receptor
The lysophospholipid receptor (LPL-R) group are members of the G protein-coupled receptor family of integral membrane proteins that are important for lipid signaling. In humans, there are eight LPL receptors Receptor may refer to: *Sensory receptor, in physiology, any structure which, on receiving environmental stimuli, produces an informative nerve impulse *Receptor (biochemistry), in biochemistry, a protein molecule that receives and responds to a n ..., each encoded by a separate gene. These LPL receptor genes are also sometimes referred to as "Edg" (an acronym for endothelial differentiation gene). Ligands The ligands for LPL-R group are the lysophospholipid extracellular lipid signaling, signaling molecules, lysophosphatidic acid (LPA) and sphingosine 1-phosphate (S1P). Origin of name The term ''lysophospholipid'' (LPL) refers to any phospholipid that is missing one of its two O-fatty acid, acyl chains. Thus, LPLs have a free alcohol in either the sn-1 or the sn-2 pos ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fingolimod
Fingolimod, sold under the brand name Gilenya, is an immunomodulating medication, mostly used for treating multiple sclerosis (MS). Fingolimod is a sphingosine-1-phosphate receptor modulator, which sequesters lymphocytes in lymph nodes, preventing them from contributing to an autoimmune reaction. It has been reported to reduce the rate of relapses in relapsing-remitting multiple sclerosis by approximately one-half over a two-year period. Medical uses Fingolimod is used in the treatment of the relapsing form of multiple sclerosis. Its effect in those with primary progressive MS is not clear. It may also be used in chronic inflammatory demyelinating polyneuropathy. Adverse effects The most common side effects of fingolimod have been head colds, headache, increased gamma-glutamyl transfer (≤15%), diarrhea (13%), nausea (13%), abdominal pain (11%) and fatigue. A few cases of skin cancer have been reported, which has also been reported in patients taking natalizumab (Tysabri), ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
S1PR1
Sphingosine-1-phosphate receptor 1 (S1P receptor 1 or S1PR1), also known as endothelial differentiation gene 1 (EDG1) is a protein that in humans is encoded by the S1PR1 gene. S1PR1 is a G-protein-coupled receptor which binds the bioactive signaling molecule sphingosine 1-phosphate (S1P). S1PR1 belongs to a sphingosine-1-phosphate receptor subfamily comprising five members (S1PR1-5). S1PR1 was originally identified as an abundant transcript in endothelial cells and it has an important role in regulating endothelial cell cytoskeletal structure, migration, capillary-like network formation and vascular maturation. In addition, S1PR1 signaling is important in the regulation of lymphocyte maturation, migration and trafficking. Structure S1PR1 like the other members of the GPCR family is composed of seven-transmembrane helices arranged in a structurally conserved bundle. As well as the other GPCRs, in the extracellular region S1PR1 is composed of three loops: ECL1 between helices I ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sphingolipid
Sphingolipids are a class of lipids containing a backbone of sphingoid bases, a set of aliphatic amino alcohols that includes sphingosine. They were discovered in brain extracts in the 1870s and were named after the mythological sphinx because of their enigmatic nature. These compounds play important roles in signal transduction and cell recognition. Sphingolipidoses, or disorders of sphingolipid metabolism, have particular impact on neural tissue. A sphingolipid with an R group consisting of a hydrogen atom only is a ceramide. Other common R groups include phosphocholine, yielding a sphingomyelin, and various sugar monomers or dimers, yielding cerebrosides and globosides, respectively. Cerebrosides and globosides are collectively known as glycosphingolipids. Structure The long-chain bases, sometimes simply known as sphingoid bases, are the first non-transient products of '' de novo'' sphingolipid synthesis in both yeast and mammals. These compounds, specifically known as phy ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sphingosine
Sphingosine (2-amino-4-trans-octadecene-1,3-diol) is an 18-carbon amino alcohol with an unsaturated hydrocarbon chain, which forms a primary part of sphingolipids, a class of cell membrane lipids that include sphingomyelin, an important phospholipid. Functions Sphingosine can be phosphorylated in vivo via two kinases, sphingosine kinase type 1 and sphingosine kinase type 2. This leads to the formation of sphingosine-1-phosphate, a potent signaling lipid. Sphingolipid metabolites, such as ceramides, sphingosine and sphingosine-1-phosphate, are lipid signaling molecules involved in diverse cellular processes. Biosynthesis Sphingosine is synthesized from palmitoyl CoA and serine in a condensation required to yield dihydrosphingosine. Dehydrosphingosine is then reduced by NADPH to dihydrosphingosine (sphinganine), acylated to dihydroceramide finally oxidized by FAD to ceramide. Sphingosine is then solely formed via degradation of sphingolipid in the lysosome. See also * ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cell Signaling
In biology, cell signaling (cell signalling in British English) or cell communication is the ability of a cell to receive, process, and transmit signals with its environment and with itself. Cell signaling is a fundamental property of all cellular life in prokaryotes and eukaryotes. Signals that originate from outside a cell (or extracellular signals) can be physical agents like mechanical pressure, voltage, temperature, light, or chemical signals (e.g., small molecules, peptides, or gas). Cell signaling can occur over short or long distances, and as a result can be classified as autocrine, juxtacrine, intracrine, paracrine, or endocrine. Signaling molecules can be synthesized from various biosynthetic pathways and released through passive or active transports, or even from cell damage. Receptors play a key role in cell signaling as they are able to detect chemical signals or physical stimuli. Receptors are generally proteins located on the cell surface or within the interio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sphingomyelin
Sphingomyelin (SPH, ˌsfɪŋɡoˈmaɪəlɪn) is a type of sphingolipid found in animal cell membranes, especially in the membranous myelin sheath that surrounds some nerve cell axons. It usually consists of phosphocholine and ceramide, or a ethanolamine, phosphoethanolamine head group; therefore, sphingomyelins can also be classified as sphingophospholipids. In humans, SPH represents ~85% of all sphingolipids, and typically make up 10–20 mol % of plasma membrane lipids. Sphingomyelin was first isolated by Germans, German chemist Johann Ludwig Wilhelm Thudichum, Johann L.W. Thudicum in the 1880s. The structure of sphingomyelin was first reported in 1927 as N-acyl-sphingosine-1-phosphorylcholine. Sphingomyelin content in mammals ranges from 2 to 15% in most tissues, with higher concentrations found in nerve tissues, red blood cells, and the ocular lenses. Sphingomyelin has significant structural and functional roles in the cell. It is a plasma membrane component and parti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ovarian Follicles
An ovarian follicle is a roughly spheroid cellular aggregation set found in the ovaries. It secretes hormones that influence stages of the menstrual cycle. At the time of puberty, women have approximately 200,000 to 300,000 follicles, each with the potential to release an egg cell (ovum) at ovulation for fertilization. These eggs are developed once every menstrual cycle with around 450–500 being ovulated during a woman's reproductive lifetime. Structure Ovarian follicles are the basic units of female reproductive biology. Each of them contains a single oocyte (immature ovum or egg cell). These structures are periodically initiated to grow and develop, culminating in ovulation of usually a single competent oocyte in humans. They also consist of granulosa cells and theca of follicle. Oocyte Once a month, one of the ovaries releases a mature egg (ovum), known as an oocyte. The nucleus of such an oocyte is called a '' germinal vesicle (see picture).'' Cumulus oophorus Cumulus ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Premature Ovarian Failure
Primary ovarian insufficiency (POI) (also called premature ovarian insufficiency, premature menopause, and premature ovarian failure) is the partial or total loss of reproductive and hormonal function of the ovaries before age 40 because of folliclular (egg producing area) dysfunction or early loss of eggs. POI can be seen as part of a continuum of changes leading to menopause that differ from age-appropriate menopause in the age of onset, degree of symptoms, and sporadic return to normal ovarian function. POI affects approximately 1 in 10,000 women under age 20, 1 in 1,000 women under age 30, and 1 in 100 of those under age 40. A medical triad for the diagnosis is amenorrhea, hypergonadotropism, and hypoestrogenism. Physical and emotional symptoms include hot flashes, night sweats, dry skin, vaginal dryness, irregular or absent menstruation, anxiety, depression, mental fog, irritability, nervousness, decreased libido, and increased autoimmune disruption. The sense of shoc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Renal Cell Carcinoma
Renal cell carcinoma (RCC) is a kidney cancer that originates in the lining of the proximal convoluted tubule, a part of the very small tubes in the kidney that transport primary urine. RCC is the most common type of kidney cancer in adults, responsible for approximately 90–95% of cases. RCC occurrence shows a male predominance over women with a ratio of 1.5:1. RCC most commonly occurs between 6th and 7th decade of life. Initial treatment is most commonly either partial or complete removal of the affected kidney(s). Where the cancer has not metastasised (spread to other organs) or burrowed deeper into the tissues of the kidney, the five-year survival rate is 65–90%, but this is lowered considerably when the cancer has spread. The body is remarkably good at hiding the symptoms and as a result people with RCC often have advanced disease by the time it is discovered. The initial symptoms of RCC often include blood in the urine (occurring in 40% of affected persons at the time th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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