Platelet-derived growth factor (PDGF) is one among numerous growth factors that regulate cell growth and division. In particular, PDGF plays a significant role in blood vessel formation, the growth of blood vessels from already-existing blood vessel tissue, mitogenesis, i.e. proliferation, of mesenchymal cells such as fibroblasts, osteoblasts, tenocytes, vascular smooth muscle cells and mesenchymal stem cells as well as chemotaxis, the directed migration, of mesenchymal cells. Platelet-derived growth factor is a dimericglycoprotein that can be composed of two A subunits (PDGF-AA), two B subunits (PDGF-BB), or one of each (PDGF-AB).
PDGF[1][2] is a potent mitogen for cells of mesenchymal origin, including fibroblasts, smooth muscle cells and glial cells. In both mouse and human, the PDGF signalling network consists of five ligands, PDGF-AA through -DD (including -AB), and two receptors, PDGFRalpha and PDGFRbeta. All PDGFs function as secreted, disulphide-linked homodimers, but only PDGFA and B can form functional heterodimers.
Though PDGF is synthesized,[3] stored (in the alpha granules of platelets),[4] and released by platelets upon activation, it is also produced by other cells including smooth muscle cells, activated macrophages, and endothelial cells[5]
Recombinant PDGF is used in medicine to help heal chronic ulcers, to heal ocular surface diseases and in orthopedic surgery and periodontics as an alternative to bone autograft to stimulate bone regeneration and repair.
The receptor for PDGF, PDGFR is classified as a receptor tyrosine kinase (RTK), a type of cell surface receptor. Two types of PDGFRs have been identified: alpha-type and beta-type PDGFRs.[8] The alpha type binds to PDGF-AA, PDGF-BB and PDGF-AB, whereas the beta type PDGFR binds with high affinity to PDGF-BB and PDGF-AB.[9]
PDGF binds to the PDGFR ligand binding pocket located within the second and third immunoglobulin domains.[10] Upon activation by PDGF, these receptors dimerise, and are "switched on" by auto-phosphorylation of several sites on their cytosolic domains, which serve to mediate binding of cofactors and subsequently activate signal transduction, for example, through the PI3K pathway or through reactive oxygen species (ROS)-mediated activation of the STAT3 pathway.[11] Downstream effects of this include regulation of gene expression and the cell cycle.
The role of PI3K has been investigated by several laboratories. Accumulating data suggests that, while this molecule is, in general, part of growth signaling complex, it plays a more profound role in controlling cell migration.[12]
The different ligand isoforms have variable affinities for the receptor isoforms, and the receptor isoforms may variably form hetero- or homo- dimers. This leads to specificity of downstream signaling. It has been shown that the sis oncogene is derived from the PDGF B-chain gene. PDGF-BB is the highest-affinity ligand for the PDGFR-beta; PDGFR-beta is a key marker of hepatic stellate cell activation in the process of fibrogenesis.[citation needed]
Function
PDGFs are mitogenic during early developmental stages, driving the proliferation of undifferentiated mesenchyme and some progenitor populations. During later maturation stages, PDGF signalling has been implicated in tissue remodelling and cellular differentiation, and in inductive events involved in patterning and morphogenesis. In addition to driving mesenchymal proliferation, PDGFs have been shown to direct the migration, differentiation and function of a variety of specialised mesenchymal and migratory cell types, both during development and in the adult animal.[13][14][15] Other growth factors in this family include vascular endothelial growth factors B and C (VEGF-B, VEGF-C)[16][17] which are active in angiogenesis and endothelial cell growth, and placenta growth factor (PlGF) which is also active in angiogenesis.[18]
PDGF plays a role in embryonic development, cell proliferation, cell migration, and angiogenesis.[19] Over-expression of PDGF has been linked to several diseases such as atherosclerosis, fibrotic disorders and malignancies. Synthesis occurs due to external stimuli such as thrombin, low oxygen tension, or other cytokines and growth factors.[20]
PDGF is a required element in cellular division for fibroblasts, a type of connective tissue cell that is especially prevalent in wound healing.[20] In essence, the PDGFs allow a cell to skip the G1 checkpoints in order to divide.[21] It has been shown that in monocytes-macrophages and fibroblasts, exogenously administered PDGF stimulates chemotaxis, proliferation, and gene expression and significantly augmented the influx of inflammatory cells and fibroblasts, accelerating extracellular matrix and collagen formation and thus reducing the time for the healing process to occur.[22]
In terms of osteogenic differentiation of mesenchymal stem cells, comparing PDGF to epidermal growth factor (EGF), which is also implicated in stimulating cell growth, proliferation, and differentiation,[23] MSCs were shown to have stronger osteogenic differentiation into bone-forming cells when stimulated by epidermal growth factor (EGF) versus PDGF. However, comparing the signaling pathways between them reveals that the PI3K pathway is exclusively activated by PDGF, with EGF having no effect. Chemically inhibiting the PI3K pathway in PDGF-stimulated cells negates the differential effect between the two growth factors, and actually gives PDGF an edge in osteogenic differentiation.[23]Wortmannin is a PI3K-specific inhibitor, and treatment of cells with Wortmannin in combination with PDGF resulted in enhanced osteoblast differentiation compared to just PDGF alone, as well as compared to EGF.[23] These results indicate that the addition of Wortmannin can significantly increase the response of cells into an osteogenic lineage in the presence of PDGF, and thus might reduce the need for higher concentrations of PDGF or other growth factors, making PDGF a more viable growth factor for osteogenic differentiation than other, more expensive growth factors currently used in the field such as BMP2.[24]
PDGF is also known to maintain proliferation of oligodendrocyte progenitor cells (OPCs).[25][26] It has also been shown that fibroblast growth factor (FGF) activates a signaling pathway that positively regulates the PDGF receptors in OPCs.[27]
History
PDGF was one of the first growth factors characterized,[28] and has led to an understanding of the mechanism of many growth factor signaling pathways.[citation needed]The first engineered dominant negative protein was designed to inhibit PDGF [29]
Medicine
Recombinant PDGF is used to help heal chronic ulcers and in orthopedic surgery and periodontics to stimulate bone regeneration and repair.[30] PDGF may be beneficial when used by itself or especially in combination with other growth factors to stimulate soft and hard tissue healing (Lynch et al. 1987, 1989, 1991, 1995).
Research
Like many other growth factors that have been linked to disease, PDGF and its receptors have provided a market for receptor antagonists to treat disease. Such antagonists include (but are not limited to) specific antibodies that target the molecule of interest, which act only in a neutralizing manner.[31]
Age related downregulation of the PDGF receptor on islet beta cells has been demonstrated to prevent islet beta cell proliferation in both animal and human cells and its re-expression triggered beta cell proliferation and corrected glucose regulation via insulin secretion.[33][34]
A non-viral PDGF "bio patch" can regenerate missing or damaged bone by delivering DNA in a nano-sized particle directly into cells via genes. Repairing bone fractures, fixing craniofacial defects and improving dental implants are among potential uses. The patch employs a collagen platform seeded with particles containing the genes needed for producing bone. In experiments, new bone fully covered skull wounds in test animals and stimulated growth in human bone marrow stromal cells.[35][36]
The addition of PDGF at specific time‐points has been shown to stabilise vasculature in collagen‐glycosaminoglycan scaffolds.[37]
Family members
Human genes encoding proteins that belong to the platelet-derived growth factor family include:
^Hannink M, Donoghue DJ (1989). "Structure and function of platelet-derived growth factor (PDGF) and related proteins". Biochim. Biophys. Acta. 989 (1): 1–10. doi:10.1016/0304-419x(89)90031-0. PMID2546599.
^Maglione D, Guerriero V, Viglietto G, Ferraro MG, Aprelikova O, Alitalo K, Del Vecchio S, Lei KJ, Chou JY, Persico MG (1993). "Two alternative mRNAs coding for the angiogenic factor, placenta growth factor (PlGF), are transcribed from a single gene of chromosome 14". Oncogene. 8 (4): 925–931. PMID7681160.
^ abAlvarez RH, Kantarjian HM, Cortes JE (September 2006). "Biology of platelet-derived growth factor and its involvement in disease". Mayo Clin. Proc. 81 (9): 1241–1257. doi:10.4065/81.9.1241. PMID16970222.
^Friedlaender GE, Lin S, Solchaga LA, Snel LB, Lynch SE (2013). "The role of recombinant human platelet-derived growth factor-BB (rhPDGF-BB) in orthopaedic bone repair and regeneration". Current Pharmaceutical Design. 19 (19): 3384–3390. doi:10.2174/1381612811319190005. PMID23432673. Demonstration of the safety and efficacy of rhPDGF-BB in the healing of chronic foot ulcers in diabetic patients and regeneration of alveolar (jaw) bone lost due to chronic infection from periodontal disease has resulted in two FDA-approved products based on this molecule
^McClintock JT, Chan IJ, Thaker SR, Katial A, Taub FE, Aotaki-Keen AE, Hjelmeland LM (1992). "Detection of c-sis proto-oncogene transcripts by direct enzyme-labeled cDNA probes and in situ hybridization". In Vitro Cell Dev Biol. 28A (2): 102–108. doi:10.1007/BF02631013. PMID1537750. S2CID9958016.
آموس يوغا معلومات شخصية الميلاد 8 ديسمبر 1992 (31 سنة)[1] فيلوربان الطول 186 سنتيمتر مركز اللعب مُدَافِع الجنسية جمهورية أفريقيا الوسطى فرنسا (3 نوفمبر 1998–)[2] المسيرة الاحترافية سنواتفريقمبارياتأهداف2010–2011 نادي سانت بريست 1 (0)2012–2012 أولمبيك ليو...
Este artigo carece de caixa informativa ou a usada não é a mais adequada. Esta página cita fontes, mas que não cobrem todo o conteúdo. Ajude a inserir referências. Conteúdo não verificável pode ser removido.—Encontre fontes: ABW • CAPES • Google (N • L • A) Depósito (nó 0) com rotas e clientes (nós de 1 a 18). O problema de roteamento de veículos capacitados (PRVC) é a variante mais estudada do problema de roteame...
Том Форсайт Особисті дані Народження 23 січня 1949(1949-01-23) Глазго, Велика Британія Смерть 14 серпня 2020(2020-08-14) (71 рік) Strathavend Громадянство Шотландія Позиція захисник Професіональні клуби* Роки Клуб І (г) 1967–1972 «Мотервелл» 150 (17) 1972–1982 «Рейнджерс» 218 (2) Національна зб...
The 2015 Iglesia ni Cristo leadership controversy is a dispute between senior members of the Iglesia ni Cristo (INC) in the Philippines. In July 2015, it was reported that the INC had expelled some of its ministers, along with high-profile members Felix Nathaniel Angel Manalo and Cristina Tenny Villanueva Manalo, the brother and mother of current INC Executive Minister Eduardo Manalo, respectively.[1] Angel and Tenny were expelled from the INC for rebellion and causing division in the...
Single contest to determine a champion of the Triple-A classification of Minor League Baseball Triple-A National Championship GameFrequencyAnnualLocation(s)Varies (see prose)InauguratedSeptember 19, 2006(AT&T Bricktown Ballpark, Oklahoma City, Oklahoma, United States)Most recentSeptember 30, 2023(Las Vegas Ballpark, Summerlin, Nevada, United States)Next eventTBAParticipantsLeague champions of the two Triple-A baseball leaguesOrganized byMinor League Baseball The Triple-A National Champion...
For other people named William or Bill Goodwin, see William Goodwin (disambiguation). The ReverendW. A. R. GoodwinGoodwin in 1926BornJune 18, 1869Richmond, VirginiaDiedSeptember 7, 1939(1939-09-07) (aged 70)EducationRichmond CollegeAlma materRoanoke CollegeVirginia Theological SeminarySpouses Evelyn Tannor (died 1915) Ethel Howard (m. 1918) Children6Parent(s)John Francis GoodwinLetitia RutherfoordSignature...
Remy LaCroixNama dalam bahasa asli(en) Remy LaCroix BiografiKelahiran(en) Ashley Brianna Cronan 26 Juni 1988 (35 tahun)San Francisco Data pribadiTinggi157 cm [convert: unit tak dikenal]Berat48 kg [convert: unit tak dikenal]Warna rambutRambut cokelat KegiatanPekerjaanPemeran pornografi Periode aktif2011 – 2017 Situs web<span%20class= penicon%20data-bridge-edit-flow=single-best-value> Laman resmi Remy LaCroix (kelahiran Juni 1988) adalah seorang aktris pornografi Amerika. ...
لقد نتج عن تطور النباتات مجموعة كبيرة من الأشكال المعقدة، بدءًا من الحصائر الطحلبية البدائية، ومرورًا بالطحالب الخضراء البحرية وغير البحرية متعددة الخلايا والنباتات اللا وعائية البرية والسراخس والنباتات الذئبية، حتى الأشكال المعقدة من كاسيات البذور وعاريات البذور الم...
نقيشة ليبيقية في متحف بَارِدُو الوطني التونسي يُقصَدُ بالكِتَابَةِ اللِيبِيقِيَّةِ مجموعَ الأبجدياتِ التي وُجِدت في ليبيا القديمة (بلاد ليبيا، وتونس، والجزائر، والمغرب الحالية). يوجد أكثرُ من ألف نقيشة ليبيقية،[1] أغلبها جنائزية، ووجيزة، وتحوي أساسا أسماءَ أعلام.[...
Chemins de fer de l'Hérault modifier - modifier le code - voir Wikidata Titre privilégié de la Compagnie Anonyme des Chemins de Fer d’Intérêt Local de l’Hérault, en date du 26 mars 1890. Créée en 1868, la Compagnie des chemins de fer d’intérêt local du département de l’Hérault construit et exploite dans ce département des lignes ferroviaires complétant les dessertes mises en place par la Compagnie du Midi[1] et le PLM[2]. Elle obtient la concession d’une premièr...
Neusee Der wiederbefüllte Neusee im Oktober 2020 Geographische Lage Bayern, Deutschland Abfluss Auweiher → Rötlbach → Starnberger See → Würm → Amper→ Isar → Donau → Schwarzes Meer Ufernaher Ort Bernried Daten Koordinaten 47° 51′ 26″ N, 11° 16′ 3″ O47.8572911.26754618Koordinaten: 47° 51′ 26″ N, 11° 16′ 3″ O Neusee (Auweiher) (Bayern) Höhe über Meeresspiegel 618 m Länge ca. 600 mdep1[1...
Village in Jaffa, Mandatory PalestineAbu Kishk ابو كشْكVillageOld school of Abu Kishk 1870s map 1940s map modern map 1940s with modern overlay map A series of historical maps of the area around Abu Kishk (click the buttons)Abu KishkLocation within Mandatory PalestineCoordinates: 32°8′11″N 34°51′55″E / 32.13639°N 34.86528°E / 32.13639; 34.86528Palestine grid136/170Geopolitical entityMandatory PalestineSubdistrictJaffaDate of depopulation30 March ...
American journalist (1920–2012) Chris EconomakiEconomaki in 2007BornChristopher Constantine Economaki(1920-10-15)October 15, 1920Brooklyn, New York, U.S.DiedSeptember 28, 2012(2012-09-28) (aged 91)Wyckoff, New Jersey, U.S.Years active1932–2008Known forMotorsports journalism Christopher Constantine Economaki (October 15, 1920 – September 28, 2012) was a pioneering American motorsports journalist, publisher, reporter, and commentator known as The Dean of American Motor...
This article needs additional citations for verification. Please help improve this article by adding citations to reliable sources. Unsourced material may be challenged and removed.Find sources: Washington Street Tunnel Chicago – news · newspapers · books · scholar · JSTOR (December 2009) (Learn how and when to remove this template message) Washington St. TunnelEast entrance(before 1884)OverviewCoordinates41°52′59.5″N 87°38′17.0″W...
1972 filmSmile Before DeathDirected bySilvio AmadioWritten bySilvio AmadioFrancesco VillaProduced bySilvio AmadioStarringJenny TamburiSilvano TranquilliRosalba NeriCinematographySilvano IppolitiEdited byFrancesco BertuccioliMusic byRoberto PregadioBob DeramentRelease date 1972 (1972) Running time88 minutesLanguageItalian Smile Before Death (Italian: Il sorriso della iena/ translation: Smile of the Hyena) is a 1972 Italian giallo film written and directed by Silvio Amadio, and starring Ro...
Cannabivarin Names Preferred IUPAC name 6,6,9-Trimethyl-3-propyl-6H-dibenzo[b,d]pyran-1-ol Other names 6,6,9-Trimethyl-3-propyl-6H-benzo[c]chromen-1-ol Identifiers CAS Number 33745-21-0 Y 3D model (JSmol) Interactive image ChemSpider 540898 Y MeSH cannabivarin PubChem CID 622545 UNII MHH8UW410N Y CompTox Dashboard (EPA) DTXSID00187421 InChI InChI=1S/C19H22O2/c1-5-6-13-10-16(20)18-14-9-12(2)7-8-15(14)19(3,4)21-17(18)11-13/h7-11,20H,5-6H2,1-4H3 YKey: SVTKBAIRFMXQQF-UHFF...
Yakubu Nazionalità Nigeria Altezza 183 cm Peso 90 kg Calcio Ruolo Attaccante Termine carriera 22 novembre 2017 - giocatore Carriera Giovanili 1994-1997 Gateway Utd1997-1998 Julius Berger1998→ Gil Vicente1998-1999 Maccabi Haifa Squadre di club1 1999-2000→ Hapoel Kfar Saba23 (6)2000-2003 Maccabi Haifa49 (24)2003-2005 Portsmouth81 (36)2005-2007 Middlesbrough73 (24)2007-2011 Everton82 (25)2011→ Leicester City20 (11)2011-2012 B...
American TV series or program Weekend LiveTitlecard for Weekend LiveGenreNews/Talk programPresented byTony Snow (2002-2003)Brian Wilson (2003-2008)Country of originUnited StatesOriginal languageEnglishProductionProduction locationWashington, D.C.Camera setupMulti-cameraRunning time120 minutesOriginal releaseNetworkFox NewsRelease2002 (2002) –February 24, 2008 (2008-02-24) Weekend Live is an American news/talk television program on Fox News Channel. The program featured l...
Balances du Laboratoire de Lavoisier utilisées pour comparer les masses des produits et réactifs d'une réaction chimique Portrait d'Antoine Lavoisier. Portrait d'Anaxagore de Clazomènes. Rien ne se perd, rien ne se crée, tout se transforme est une citation apocryphe d'Antoine Lavoisier sur la conservation des masses lors du changement d'état de la matière. Citation originale Dans son Traité élémentaire de chimie, en 1789, Antoine Lavoisier écrit[1] : « On voit que, pour ...