Sphingosine-1-phosphate

Last updated
Sphingosine-1-phosphate
Sphingosine-1-phosphate.svg
Sphingosine-1-phosphate-anion-3D-spacefill.png
Names
Preferred IUPAC name
(2S,3R,4E)-2-Amino-3-hydroxyoctadec-4-en-1-yl dihydrogen phosphate
Identifiers
3D model (JSmol)
ChEBI
ChEMBL
ChemSpider
ECHA InfoCard 100.164.436 OOjs UI icon edit-ltr-progressive.svg
KEGG
MeSH sphingosine+1-phosphate
PubChem CID
UNII
  • InChI=1S/C18H38NO5P/c1-2-3-4-5-6-7-8-9-10-11-12-13-14-15-18(20)17(19)16-24-25(21,22)23/h14-15,17-18,20H,2-13,16,19H2,1H3,(H2,21,22,23)/b15-14+/t17-,18+/m0/s1 Yes check.svgY
    Key: DUYSYHSSBDVJSM-KRWOKUGFSA-N Yes check.svgY
  • InChI=1/C18H38NO5P/c1-2-3-4-5-6-7-8-9-10-11-12-13-14-15-18(20)17(19)16-24-25(21,22)23/h14-15,17-18,20H,2-13,16,19H2,1H3,(H2,21,22,23)/b15-14+/t17-,18+/m0/s1
    Key: DUYSYHSSBDVJSM-KRWOKUGFBM
  • O=P(O)(OC[C@H](N)[C@H](O)/C=C/CCCCCCCCCCCCC)O
Properties
C18H38NO5P
Molar mass 379.472
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
X mark.svgN  verify  (what is  Yes check.svgYX mark.svgN ?)

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.

Contents

Production

S1P is formed from ceramide, [1] which is composed of a sphingosine and a fatty acid. Ceramidase, an enzyme primarily present in plasma membrane, will convert ceramide to sphingosine. [1] Sphingosine is then phosphorylated by sphingosine kinase (SK) isoenzymes. [2] There are two identified mammalian isoenzymes, SK1 and SK2. [3] [4] [5] [6] These two enzymes have different tissue distribution. SK1 is highly expressed in spleen, lung and leukocytes, [3] while SK2 is highly expressed in liver and kidney. [3] SK2 is located mainly in the mitochondria, nucleus and the endoplasmic reticulum whereas SK1 is mainly located in cytoplasm and the cell membrane. [7] [8] [9]

Metabolism and degradation

S1P can be dephosphorylated to sphingosine by sphingosine phosphatases and can be irreversibly degraded by an enzyme, sphingosine phosphate lyase.

Function

S1P is a blood borne lipid mediator, in particular in association with lipoproteins such as high density lipoprotein (HDL). [10] It is less abundant in tissue fluids. This is referred to as the S1P gradient, which seems to have biological significance in immune cell trafficking.

Originally thought as an intracellular second messenger, it was discovered to be an extracellular ligand for G protein-coupled receptor S1PR1 in 1998. It is now known that sphingosine-1-phosphate receptors (S1P receptors) are members of the lysophospholipid receptor family. There are five described to date. Most of the biological effects of S1P are mediated by signaling through the cell surface receptors.

Although S1P is of importance in the entire human body, it is a major regulator of vascular and immune systems. In addition, it might be relevant in the skin. In the vascular system, S1P regulates angiogenesis, vascular stability, and permeability. In the immune system, it is now recognized as a major regulator of trafficking of T- and B-cells. S1P interaction with its receptor S1PR1 is needed for the egress of immune cells from the lymphoid organs (such as thymus and lymph nodes) into the lymphatic vessels. Inhibition of S1P receptors was shown to be critical for immunomodulation. S1P has also been shown to directly suppress TLR mediated immune response from T cells. [11]

A research team, led by a scientist at Weill Cornell Medical College, has discovered that red blood cells perform a second vital function: angiogenesis. Given its role in creating new blood vessels, scientists recognize S1P as vital to human health — and a player in some diseases, such as cancer. And although S1P is known to be blood borne, no one realized until this study that S1P is supplied by red blood cells to control blood vessel growth.

Clinical significance

The levels of S1P (in a range of 5–40 μmol/L) are 5 to 10 times up-regulated in ovarian cancer patients' ascites. S1P at this physiological concentration stimulates migration and invasion of epithelial ovarian cancer cells but inhibits migration of normal ovarian surface epithelial cells. [12] Most (more than 90%) ovarian cancers arise from the epithelium of the ovary. Therefore, extracellular S1P could have an important role in cancer progression by promoting migration of epithelial ovarian cancer cells.

Ozonization of human blood is associated with increased concentrations of S1P in the plasma. [13]

In addition, S1P modulates the proliferation of skin cells. This in particular applies to keratinocytes [14] while fibroblasts are not addressed in this way, apart from cell growth and differentiation. While S1P suppresses epidermal proliferation as the glucocorticoids do, it differs from them in so far, as proliferation of dermal fibroblasts is not reduced. In fact, S1P even activates fibroblast-derived extracellular matrix protein production.

As a drug

Administration of S1P has been shown to protect oocytes from chemotherapeutic agents in vitro, [15] [16] [17] as well as in vivo from chemotherapeutic and radiation therapies. [15] [18] [19] [20] which otherwise induce apoptosis of the cells. S1P has protected ovarian tissue xenografts in SCID mouse models from radiation induced atresia. [20] In animal models these protected oocytes have been used to produce healthy live young. [18] [21] Radiotherapies and chemotherapies can cause apoptosis of ovarian follicles, causing premature ovarian failure, [22] and so S1P is of great interest in fertility preservation. [23] However, its mechanism of inhibiting the sphingomyelin apoptotic pathway may also interfere with the apoptosis action of chemotherapy drugs. [24]

Due to the hyperproliferative action against epidermal cells, S1P has been considered as an active pharmaceutical ingredient for hyperproliferative skin diseases, in particular, psoriasis vulgaris and acne vulgaris.[ citation needed ]

Although S1P is active at very low concentrations, bioavailability of the compound in human skin is a concern. Therefore, a topical formulation based on specific drug carriers has been considered inevitable.[ citation needed ]

As a drug target

Lpath Inc has produced and optimized a monoclonal anti-S1P antibody (Sphingomab). Sphingomab can absorb S1P from the extracellular fluid, thereby lowering the effective concentration of S1P.[ citation needed ]

Sonepcizumab is an experimental anti-S1P monoclonal antibody that has had a phase II clinical trial for renal cell carcinoma. [25] Sonepcizumab (LT1009) as ASONEP (for intravenous injection) has been studied for solid tumours. [26] As iSONEP, a formulation for intravitreal injection, it has been studied for age-related macular degeneration. [27]

S1P receptor(s) as a drug target

There are 5 types of Sphingosine-1-phosphate receptor.

S1P receptor modulators

The drug fingolimod (FTY720), which agonizes the S1P receptor, [28] prevents autoimmune lymphocytes from moving from the lymphoid organs into the central nervous system. It has been shown in phase III clinical trials to reduce relapses and improve other outcomes in multiple sclerosis. [29] [30] S1P, as well as FTY720, has been shown to have anti-inflammatory properties at low concentrations and prevent monocyte:endothelial interactions in aorta, possibly through the S1P1 receptor. [31] [32] The S1P receptor agonist etrasimod has been shown to induce remission in patient with ulcerative colitis. [33]

ONO-4641 (a drug of Ono Pharmaceutical Co., Ltd.) is a sphingosine-1-phosphate (S1P) receptor agonist which keeps lymphocytes in lymph nodes and thereby inhibits the infiltration of lymphocytes into lesions. The compound is therefore expected to be a drug for the treatment of auto-immune diseases such as multiple sclerosis, which is regarded as an intractable disease.[ citation needed ]

Ozanimod is an agonist of the S1P1 and S1P5 receptors. [34] and has been studied for various forms of multiple sclerosis. [35]

See also

Notes

  1. 1 2 Mendelson K, Evans T, Hla T (1 January 2014). "Sphingosine 1-phosphate signalling". Development. 141 (1): 5–9. doi:10.1242/dev.094805. ISSN   0950-1991. PMC   3865745 . PMID   24346695.
  2. Spiegel S, Milstien S (26 January 2007). "Functions of the multifaceted family of sphingosine kinases and some close relatives". The Journal of Biological Chemistry. 282 (4): 2125–2129. doi: 10.1074/jbc.R600028200 . ISSN   0021-9258. PMID   17135245.
  3. 1 2 3 Liu H, Sugiura M, Nava VE, Edsall LC, Kono K, Poulton S, Milstien S, Kohama T, Spiegel S (30 June 2000). "Molecular cloning and functional characterization of a novel mammalian sphingosine kinase type 2 isoform". The Journal of Biological Chemistry. 275 (26): 19513–19520. doi: 10.1074/jbc.M002759200 . ISSN   0021-9258. PMID   10751414.
  4. Maceyka M, Sankala H, Hait NC, Le Stunff H, Liu H, Toman R, Collier C, Zhang M, Satin LS, Merrill AH, Milstien S (4 November 2005). "SphK1 and SphK2, sphingosine kinase isoenzymes with opposing functions in sphingolipid metabolism". The Journal of Biological Chemistry. 280 (44): 37118–37129. doi: 10.1074/jbc.M502207200 . ISSN   0021-9258. PMID   16118219.
  5. Liu H, Chakravarty D, Maceyka M, Milstien S, Spiegel S (2002). "Sphingosine kinases: a novel family of lipid kinases". Progress in Nucleic Acid Research and Molecular Biology. 71: 493–511. doi:10.1016/s0079-6603(02)71049-0. ISBN   9780125400718. ISSN   0079-6603. PMID   12102559.
  6. Escarcega RD, McCullough LD, Tsvetkov AS (2021). "The Functional Role of Sphingosine Kinase 2". Frontiers in Molecular Biosciences. 8. doi: 10.3389/fmolb.2021.683767 . PMC   8160245 . PMID   34055895.
  7. Strub GM, Paillard M, Liang J, Gomez L, Allegood JC, Hait NC, Maceyka M, Price MM, Chen Q, Simpson DC, Kordula T (February 2011). "Sphingosine-1-phosphate produced by sphingosine kinase 2 in mitochondria interacts with prohibitin 2 to regulate complex IV assembly and respiration". FASEB Journal. 25 (2): 600–612. doi: 10.1096/fj.10-167502 . ISSN   1530-6860. PMC   3023391 . PMID   20959514.
  8. Adams DR, Pyne S, Pyne NJ (May 2016). "Sphingosine Kinases: Emerging Structure-Function Insights" (PDF). Trends in Biochemical Sciences. 41 (5): 395–409. doi:10.1016/j.tibs.2016.02.007. ISSN   0968-0004. PMID   27021309.
  9. Fukuda Y, Kihara A, Igarashi Y (12 September 2003). "Distribution of sphingosine kinase activity in mouse tissues: contribution of SPHK1". Biochemical and Biophysical Research Communications. 309 (1): 155–160. doi:10.1016/s0006-291x(03)01551-1. ISSN   0006-291X. PMID   12943676.
  10. Sattler K, Levkau B (May 2009). "Sphingosine-1-phosphate as a mediator of high-density lipoprotein effects in cardiovascular protection". Cardiovascular Research. 82 (2): 201–11. doi: 10.1093/cvr/cvp070 . PMID   19233866.
  11. Sharma, N, et al. (2013). "Sphingosine-1-phosphate suppresses TLR-induced CXCL8 secretion from human T cells". J Leukoc Biol. 93 (4): 521–528. doi: 10.1189/jlb.0712328 . PMID   23345392.
  12. Wang, D, et al. (2008). "S1P differentially regulates migration of human ovarian cancer and human ovarian surface epithelial cells". Mol Cancer Ther. 7 (7): 1993–2002. doi:10.1158/1535-7163.MCT-08-0088. PMC   2649755 . PMID   18645009.
  13. Boczkowska-Radziwon B, Chabowska AM, Blachnio-Zabielska A, Lukaszuk B, Lipska A, Chabowski A, Radziwon P (April 2015). "Ozonation of human blood increases sphingosine-1-phosphate in plasma". Journal of Physiology and Pharmacology. 66 (2): 267–72. PMID   25903957.
  14. Manggau M, Kim DS, Ruwisch L, et al. (November 2001). "1Alpha,25-dihydroxyvitamin D3 protects human keratinocytes from apoptosis by the formation of sphingosine-1-phosphate". The Journal of Investigative Dermatology. 117 (5): 1241–9. doi: 10.1046/j.0022-202x.2001.01496.x . PMID   11710939.
  15. 1 2 Morita Y, Perez GI, Paris F, et al. (October 2000). "Oocyte apoptosis is suppressed by disruption of the acid sphingomyelinase gene or by sphingosine-1-phosphate therapy". Nature Medicine. 6 (10): 1109–14. doi:10.1038/80442. PMID   11017141. S2CID   33216920.
  16. Jurisicova A, Lee HJ, D'Estaing SG, Tilly J, Perez GI (September 2006). "Molecular requirements for doxorubicin-mediated death in murine oocytes". Cell Death and Differentiation. 13 (9): 1466–74. doi: 10.1038/sj.cdd.4401819 . PMID   16439991.
  17. Perez GI, Knudson, C. Michael, Leykin, Lucy, Korsmeyer, Stanley J., Tilly, Jonathan L. (1 November 1997). "Apoptosis-associated signaling pathways are required for chemotherapy-mediated female germ cell destruction". Nature Medicine. 3 (11): 1228–1232. doi:10.1038/nm1197-1228. PMID   9359697. S2CID   32735595.
  18. 1 2 Paris F, Perez GI, Fuks Z, et al. (September 2002). "Sphingosine 1-phosphate preserves fertility in irradiated female mice without propagating genomic damage in offspring". Nature Medicine. 8 (9): 901–2. doi:10.1038/nm0902-901. PMID   12205432. S2CID   2647395.
  19. Kaya H, Desdicioglu R, Sezik M, et al. (March 2008). "Does sphingosine-1-phosphate have a protective effect on cyclophosphamide- and irradiation-induced ovarian damage in the rat model?". Fertility and Sterility. 89 (3): 732–5. doi:10.1016/j.fertnstert.2007.03.065. PMID   17517398.
  20. 1 2 Zelinski MB, Murphy MK, Lawson MS, et al. (March 2011). "In vivo delivery of FTY720 prevents radiation-induced ovarian failure and infertility in adult female nonhuman primates". Fertility and Sterility. 95 (4): 1440–5.e1–7. doi:10.1016/j.fertnstert.2011.01.012. PMC   3063448 . PMID   21316047.
  21. Hancke K, Strauch O, Kissel C, Göbel H, Schäfer W, Denschlag D (January 2007). "Sphingosine 1-phosphate protects ovaries from chemotherapy-induced damage in vivo". Fertility and Sterility. 87 (1): 172–7. doi: 10.1016/j.fertnstert.2006.06.020 . PMID   17081530.
  22. Byrne J, Fears TR, Gail MH, et al. (March 1992). "Early menopause in long-term survivors of cancer during adolescence". American Journal of Obstetrics and Gynecology. 166 (3): 788–93. doi:10.1016/0002-9378(92)91335-8. PMID   1550144.
  23. Blumenfeld Z (1 September 2012). "Preservation of ovarian function and fertility despite gonadotoxic chemotherapy". Expert Review of Endocrinology & Metabolism. 7 (5): 567–576. doi:10.1586/eem.12.40. PMID   30780892. S2CID   59105653.
  24. Roness H, Kalich-Philosoph L, Meirow D (2014). "Prevention of chemotherapy-induced ovarian damage: possible roles for hormonal and non-hormonal attenuating agents". Human Reproduction Update. 20 (5): 759–774. doi: 10.1093/humupd/dmu019 . ISSN   1355-4786. PMID   24833728.
  25. "Sonepcizumab Failed PFS Endpoint, but Had Promising OS, in Metastatic RCC". Archived from the original on 6 January 2019. Retrieved 22 November 2016.
  26. Safety Study of ASONEP (Sonepcizumab/LT1009) to Treat Advanced Solid Tumors (ASONEP)
  27. Safety Study of iSONEP (Sonepcizumab/LT1009) to Treat Neovascular Age-related Macular Degeneration
  28. Baumrucker, T, et al. (2007). "FTY720, an immunomodulatory sphingolipid mimetic: translation of a novel mechanism into clinical benefit in multiple sclerosis". Expert Opin Investig Drugs. 16 (3): 283–289. doi:10.1517/13543784.16.3.283. PMID   17302523. S2CID   23289454.
  29. Kappos L, Radue EW, O'Connor P, et al. (February 2010). "A placebo-controlled trial of oral fingolimod in relapsing multiple sclerosis". The New England Journal of Medicine. 362 (5): 387–401. doi:10.1056/NEJMoa0909494. hdl: 11858/00-001M-0000-0012-1FF5-A . PMID   20089952.
  30. Cohen JA, Barkhof F, Comi G, et al. (February 2010). "Oral fingolimod or intramuscular interferon for relapsing multiple sclerosis". The New England Journal of Medicine. 362 (5): 402–15. doi: 10.1056/NEJMoa0907839 . hdl:2078.1/124998. PMID   20089954.
  31. Bolick DT, Srinivasan S, Kim KW, et al. (May 2005). "Sphingosine-1-Phosphate Prevents Tumor Necrosis Factor-α–Mediated Monocyte Adhesion to Aortic Endothelium in Mice". Arteriosclerosis, Thrombosis, and Vascular Biology. 25 (5): 976–81. doi: 10.1161/01.ATV.0000162171.30089.f6 . PMID   15761190.
  32. Whetzel AM, Bolick DT, Srinivasan S, et al. (September 2006). "Sphingosine-1 phosphate prevents monocyte/endothelial interactions in type 1 diabetic NOD mice through activation of the S1P1 receptor". Circulation Research. 99 (7): 731–9. doi: 10.1161/01.RES.0000244088.33375.52 . PMID   16960101.
  33. Sandborn WJ, Vermeire S, Peyrin-Biroulet L, Dubinsky MC, Panes J, Yarur A, Ritter T, Baert F, Schreiber S, Sloan S, Cataldi F, Shan K, Rabbat CJ, Chiorean M, Wolf DC, Sands BE, D'Haens G, Danese S, Goetsch M, Feagan BG (April 2023). "Etrasimod as induction and maintenance therapy for ulcerative colitis (ELEVATE): two randomised, double-blind, placebo-controlled, phase 3 studies". The Lancet. 401 (10383): 1159–1171. doi: 10.1016/S0140-6736(23)00061-2 . PMID   36871574.
  34. Scott FL, Clemons B, Brooks J, Brahmachary E, Powell R, Dedman H, Desale HG, Timony GA, Martinborough E (1 June 2016). "Ozanimod (RPC1063) is a potent sphingosine-1-phosphate receptor-1 (S1P1) and receptor-5 (S1P5) agonist with autoimmune disease-modifying activity". British Journal of Pharmacology. 173 (11): 1778–1792. doi:10.1111/bph.13476. ISSN   1476-5381. PMC   4867749 . PMID   26990079.
  35. New Frontiers in S1P Modulators. March 2017

Related Research Articles

<span class="mw-page-title-main">Kinase</span> Enzyme catalyzing transfer of phosphate groups onto specific substrates

In biochemistry, a kinase is an enzyme that catalyzes the transfer of phosphate groups from high-energy, phosphate-donating molecules to specific substrates. This process is known as phosphorylation, where the high-energy ATP molecule donates a phosphate group to the substrate molecule. This transesterification produces a phosphorylated substrate and ADP. Conversely, it is referred to as dephosphorylation when the phosphorylated substrate donates a phosphate group and ADP gains a phosphate group. These two processes, phosphorylation and dephosphorylation, occur four times during glycolysis.

<span class="mw-page-title-main">Sphingolipid</span> Family of chemical compounds

Sphingolipids are a class of lipids containing a backbone of sphingoid bases, which are 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 a terminal hydroxyl group is a ceramide. Other common groups bonded to the terminal oxygen atom include phosphocholine, yielding a sphingomyelin, and various sugar monomers or dimers, yielding cerebrosides and globosides, respectively. Cerebrosides and globosides are collectively known as glycosphingolipids.

<span class="mw-page-title-main">Fingolimod</span> Chemical compound

Fingolimod, sold under the brand name Gilenya, is an immunomodulating medication, used for the treatment of multiple sclerosis. 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.

<span class="mw-page-title-main">Ceramide</span> Family of waxy lipid molecules

Ceramides are a family of waxy lipid molecules. A ceramide is composed of sphingosine and a fatty acid joined by an amide bond. Ceramides are found in high concentrations within the cell membrane of eukaryotic cells, since they are component lipids that make up sphingomyelin, one of the major lipids in the lipid bilayer. Contrary to previous assumptions that ceramides and other sphingolipids found in cell membrane were purely supporting structural elements, ceramide can participate in a variety of cellular signaling: examples include regulating differentiation, proliferation, and programmed cell death (PCD) of cells.

<span class="mw-page-title-main">Sphingosine kinase</span> Class of enzymes

Sphingosine kinase (SphK) is a conserved lipid kinase that catalyzes formation sphingosine-1-phosphate (S1P) from the precursor sphingolipid sphingosine. Sphingolipid metabolites, such as ceramide, sphingosine and sphingosine-1-phosphate, are lipid second messengers involved in diverse cellular processes. There are two forms of SphK, SphK1 and SphK2. SphK1 is found in the cytosol of eukaryotic cells, and migrates to the plasma membrane upon activation. SphK2 is localized to the nucleus.

<span class="mw-page-title-main">Lipid signaling</span> Biological signaling using lipid molecules

Lipid signaling, broadly defined, refers to any biological cell signaling event involving a lipid messenger that binds a protein target, such as a receptor, kinase or phosphatase, which in turn mediate the effects of these lipids on specific cellular responses. Lipid signaling is thought to be qualitatively different from other classical signaling paradigms because lipids can freely diffuse through membranes. One consequence of this is that lipid messengers cannot be stored in vesicles prior to release and so are often biosynthesized "on demand" at their intended site of action. As such, many lipid signaling molecules cannot circulate freely in solution but, rather, exist bound to special carrier proteins in serum.

<span class="mw-page-title-main">Sphingosine kinase 1</span> Protein-coding gene in the species Homo sapiens

Sphingosine kinase 1 is an enzyme that in humans is encoded by the SPHK1 gene.

<span class="mw-page-title-main">S1PR1</span> Protein and coding gene in humans

Sphingosine-1-phosphate receptor 1, 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.

<span class="mw-page-title-main">CD69</span>

CD69 is a human transmembrane C-Type lectin protein encoded by the CD69 gene. It is an early activation marker that is expressed in hematopoietic stem cells, T cells, and many other cell types in the immune system. It is also implicated in T cell differentiation as well as lymphocyte retention in lymphoid organs.

<span class="mw-page-title-main">S1PR3</span> Protein and coding gene in humans

Sphingosine-1-phosphate receptor 3 also known as S1PR3 is a human gene which encodes a G protein-coupled receptor which binds the lipid signaling molecule sphingosine 1-phosphate (S1P). Hence this receptor is also known as S1P3.

<span class="mw-page-title-main">S1PR4</span> Protein-coding gene in the species Homo sapiens

Sphingosine-1-phosphate receptor 4 also known as S1PR4 is a human gene which encodes a G protein-coupled receptor which binds the lipid signaling molecule sphingosine 1-phosphate (S1P). Hence this receptor is also known as S1P4.

<span class="mw-page-title-main">S1PR2</span> Protein and coding gene in humans

Sphingosine-1-phosphate receptor 2, also known as S1PR2 or S1P2, is a human gene which encodes a G protein-coupled receptor which binds the lipid signaling molecule sphingosine 1-phosphate (S1P).

Safingol is a lyso-sphingolipid protein kinase inhibitor. It has the molecular formula C18H39NO2 and is a colorless solid. Medicinally, safingol has demonstrated promising anticancer potential as a modulator of multi-drug resistance and as an inducer of necrosis. The administration of safingol alone has not been shown to exert a significant effect on tumor cell growth. However, preclinical and clinical studies have shown that combining safingol with conventional chemotherapy agents such as fenretinide, vinblastine, irinotecan and mitomycin C can dramatically potentiate their antitumor effects. Currently in Phase I clinical trials, it is believed to be safe to co-administer with cisplatin.

<span class="mw-page-title-main">SPHK2</span> Protein-coding gene in the species Homo sapiens

Sphingosine kinase 2 is a protein that in humans is encoded by the SPHK2 gene.

<span class="mw-page-title-main">Sphingosine-1-phosphate receptor</span>

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.

Sarah Spiegel is professor and chair of the Department of Biochemistry and Molecular Biology at Virginia Commonwealth University (VCU). In the mid-1990s she discovered the sphingosine-1-phosphate (S1P) molecule, a lipid which has been identified as a signaler for the spread of cancer, inflammation, and cardiovascular disease. Her research continues to focus on S1P.

<span class="mw-page-title-main">Ozanimod</span> Medication

Ozanimod, sold under the brand name Zeposia, is an immunomodulatory medication for the treatment of relapsing multiple sclerosis and ulcerative colitis. It acts as a sphingosine-1-phosphate receptor (S1PR) agonist, sequestering lymphocytes to peripheral lymphoid organs and away from their sites of chronic inflammation.

<span class="mw-page-title-main">Sphingosine-1-phosphate receptor modulator</span> Drug class

Sphingosine-1-phosphate receptor modulators are a class of drugs used as immunomodulators, most notably in cases of multiple sclerosis.

Cells destined for apoptosis release molecules referred to as find-me signals. These signal molecules are used to attract phagocytes which engulf and eliminate damaged cells. Find-me signals are typically released by the apoptotic cells while the cell membrane remains intact. This ensures that the phagocytic cells are able to remove the dying cells before their membranes are compromised. A leaky membrane leads to secondary necrosis which may cause additional inflammation, therefore, it is best to remove dying cells before this occurs. One cell is capable of releasing multiple find-me signals. Should a cell lack the ability to release its find-me signal, other cells may release additional find-me signals to overcome the discrepancy.

<span class="mw-page-title-main">Cell extrusion</span> Process in cell biology

Cell extrusion, discovered in 2001, is a process conserved in epithelial from humans to sea sponge to seamlessly remove unwanted or dying cells while maintaining the integrity of the epithelial barrier. If cells were to die without extrusion, gaps would be created, compromising the epithelia's function. While cell targeted to die by apoptotic stimuli extrude to prevent gaps from forming, most cells die as a result of extruding live cells. To maintain epithelial cell number homeostasis, live cells extrude when they become too crowded.

References

Further reading