Culture of Embryonic Mouse Cochlear Explants and Gene Transfer by Electroporation

Auditory hair cells located within the mouse organ of Corti detect and transmit sound information to the central nervous system. The mechanosensory hair ...

Medical University of South Carolina, College of Medicine

The DNA damage/replication checkpoints act by sensing the presence of damaged DNA or stalled replication forks and initiate signaling pathways that arrest cell cycle progression. Here we report the cloning and characterization of Xenopus orthologues of the RFCand PCNA-related checkpoint proteins. XRad17 shares regions of homology with the five subunits of Replication factor C. XRad9, XRad1, and XHus1 (components of the 9-1-1 complex) all show homology to the DNA polymerase processivity factor PCNA. We demonstrate that these proteins associate with chromatin and are phosphorylated when replication is inhibited by aphidicolin. Phosphorylation of X9-1-1 is caffeine sensitive, but the chromatin association of XRad17 and the X9-1-1 complex after replication block is unaffected by caffeine. This suggests that the X9-1-1 complex can associate with chromatin independently of XAtm/XAtr activity. We further demonstrate that XRad17 is essential for the chromatin binding and checkpoint-dependent phosphorylation of X9-1-1 and for the activation of XChk1 when the replication checkpoint is induced by aphidicolin. XRad17 is not, however, required for the activation of XCds1 in response to dsDNA ends.

XRad17 is required for the activation of XChk1 but not XCds1 during checkpoint signaling in Xenopus.

&#x78B1;&#x6027;&#x6210;&#x7EA4;&#x7EF4;&#x7EC6;&#x80DE;&#x751F;&#x957F;&#x56E0;&#x5B50;&#x53D7;&#x4F53; 3 (Fgfr3) &#x5220;&#x9664;&#x4F1A;&#x5BFC;&#x81F4;&#x7531;&#x4E8E;&#x53D1;&#x5C55; Corti&#xFF0C;&#x8033;&#x8717;&#x611F;&#x89C9;&#x4E0A;&#x76AE;&#x7684;&#x7F3A;&#x9677;&#x5C0F;&#x9F20;&#x7684;&#x542C;&#x529B;&#x635F;&#x4F24;&#x3002;&#x82E5;&#x8981;&#x68C0;&#x67E5;&#x7684; FGFR3 &#x542C;&#x89C9;&#x53D1;&#x5C55;&#x4E2D;&#x7684;&#x4F5C;&#x7528;&#xFF0C;&#x4ECE; Fgfr3(-/-) &#x5C0F;&#x9F20;&#x8033;&#x8717;&#x5BA1;&#x67E5;&#x4E86;&#x4F7F;&#x7528;&#x89E3;&#x5256;&#x548C;&#x751F;&#x7406;&#x7684;&#x65B9;&#x6CD5;&#x3002;&#x5220;&#x9664; Fgfr3 &#x5BFC;&#x81F4;&#x7F3A;&#x4E4F;&#x5185;&#x652F;&#x67F1;&#x7EC6;&#x80DE;&#x548C;&#x5176;&#x4ED6;&#x7EC6;&#x80DE;&#x7C7B;&#x578B;&#xFF0C;&#x8FD9;&#x8868;&#x660E; FGFR3 &#x8C03;&#x8282;&#x7EC6;&#x80DE;&#x547D;&#x8FD0;&#x6709;&#x6240;&#x589E;&#x52A0;&#x3002;&#x5916;&#x6BDB;&#x7EC6;&#x80DE;&#x5206;&#x5316;&#x8FC7;&#x7A0B;&#x4E2D;&#x7684;&#x7F3A;&#x9677;&#x4E5F;&#x6709;&#x4EBA;&#x89C2;&#x5BDF;&#x5230;&#xFF0C;&#x5F88;&#x53EF;&#x80FD;&#x4EE3;&#x8868;&#x542C;&#x529B;&#x635F;&#x5931;&#x7684;&#x4E3B;&#x8981;&#x57FA;&#x7840;&#x3002;&#x6B64;&#x5916;&#xFF0C;&#x795E;&#x7ECF;&#x652F;&#x914D;&#x7F3A;&#x9677;&#x68C0;&#x6D4B;&#x5230;&#x7B26;&#x5408;&#x7684;&#x652F;&#x67F1;&#x7EC6;&#x80DE;&#x7EA4;&#x7EF4;&#x6307;&#x5BFC;&#x5C5E;&#x6027;&#x4E2D;&#x7684;&#x66F4;&#x6539;&#x3002;&#x8981;&#x6F84;&#x6E05;&#x7684; FGFR3 &#x4F5C;&#x7528;&#x673A;&#x5236;&#xFF0C;&#x6211;&#x4EEC;&#x5BA1;&#x67E5;&#x4E86; Bmp4&#xFF0C;&#x5DF2;&#x77E5;&#x76EE;&#x6807;&#x7684;&#x8868;&#x8FBE;&#x3002;Fgfr3(-/-) &#x8033;&#x8717;&#x4E2D;&#x589E;&#x52A0; Bmp4 &#x548C;&#x5916;&#x6E90;&#x5E94;&#x7528;&#x9AA8;&#x5F62;&#x6001;&#x53D1;&#x751F;&#x86CB;&#x767D; 4 (BMP4) &#x5230;&#x4EBA;&#x5DE5;&#x8033;&#x8717;&#x5916;&#x690D;&#x4F53;&#x8BF1;&#x5BFC;&#x5916;&#x6BDB;&#x7EC6;&#x80DE;&#xFF0C;&#x5EFA;&#x8BAE;&#x5728;&#x6F14;&#x5531;&#x4F1A;&#x8981;&#x9635;&#x5217;&#x8033;&#x8717; Fgf &#x548C; Bmp &#x4FE1;&#x53F7;&#x6CD5;&#x7684;&#x663E;&#x8457;&#x589E;&#x52A0;&#x3002;

&#x4E2D;&#x65AD;&#x7684;&#x6210;&#x7EA4;&#x7EF4;&#x7EC6;&#x80DE;&#x751F;&#x957F;&#x56E0;&#x5B50;&#x53D7;&#x4F53; 3 &#x4FE1;&#x53F7;&#x7ED3;&#x679C;&#x5728;&#x7EC6;&#x80DE;&#x5206;&#x5316;&#x3001; &#x795E;&#x7ECF;&#x5143;&#x7684;&#x9635;&#x5217;&#x548C;&#x542C;&#x529B;&#x635F;&#x4F24;&#x7684;&#x7F3A;&#x9677;&#x3002;

Deletion of fibroblast growth factor receptor 3 (Fgfr3) leads to hearing impairment in mice due to defects in the development of the organ of Corti, the sensory epithelium of the Cochlea. To examine the role of FGFR3 in auditory development, cochleae from Fgfr3(-/-) mice were examined using anatomical and physiological methods. Deletion of Fgfr3 leads to the absence of inner pillar cells and an increase in other cell types, suggesting that FGFR3 regulates cell fate. Defects in outer hair cell differentiation were also observed and probably represent the primary basis for hearing loss. Furthermore, innervation defects were detected consistent with changes in the fiber guidance properties of pillar cells. To elucidate the mechanisms underlying the effects of FGFR3, we examined the expression of Bmp4, a known target. Bmp4 was increased in Fgfr3(-/-) cochleae, and exogenous application of bone morphogenetic protein 4 (BMP4) onto cochlear explants induced a significant increase in the outer hair cells, suggesting the Fgf and Bmp signaling act in concert to pattern the cochlea.

Disruption of fibroblast growth factor receptor 3 signaling results in defects in cellular differentiation, neuronal patterning, and hearing impairment.

Suppression de r&#xE9;cepteur du facteur de croissance des fibroblastes 3 (FGFR3) conduit &#xE0; la d&#xE9;ficience auditive chez les souris en raison de d&#xE9;fauts dans le d&#xE9;veloppement de l&#x26;#39;organe de Corti, l&#x26;#39;&#xE9;pith&#xE9;lium sensoriel de la cochl&#xE9;e. Pour examiner le r&#xF4;le de FGFR3 dans le d&#xE9;veloppement auditif, cochl&#xE9;e de FGFR3 (- / -) chez la souris ont &#xE9;t&#xE9; examin&#xE9;s en utilisant des m&#xE9;thodes anatomiques et physiologiques. Suppression de FGFR3 conduit &#xE0; l&#x26;#39;absence de cellules pilier interne et une augmentation d&#x26;#39;autres types cellulaires, sugg&#xE9;rant que FGFR3 r&#xE9;glemente le destin des cellules. Des d&#xE9;fauts dans la diff&#xE9;renciation des cellules cili&#xE9;es externes ont &#xE9;galement &#xE9;t&#xE9; observ&#xE9;es et repr&#xE9;sentent probablement la raison principale de la perte d&#x26;#39;audition. En outre, les d&#xE9;fauts ont &#xE9;t&#xE9; d&#xE9;tect&#xE9;s innervation compatible avec les changements dans les propri&#xE9;t&#xE9;s d&#x26;#39;orientation des fibres de cellules pilier. Pour &#xE9;lucider les m&#xE9;canismes qui sous-tendent les effets de FGFR3, nous avons examin&#xE9; l&#x26;#39;expression de BMP4, une cible connue. Bmp4 a &#xE9;t&#xE9; augment&#xE9; dans FGFR3 (- / -) cochl&#xE9;e, et l&#x26;#39;application exog&#xE8;ne de prot&#xE9;ines morphog&#xE9;n&#xE9;tiques osseuses 4 (BMP4) sur des explants cochl&#xE9;aires induit une augmentation significative dans les cellules cili&#xE9;es externes, ce qui sugg&#xE8;re le FGF et Bmp signalisation agissent de concert pour motif de la cochl&#xE9;e.

Perturbation des Fibroblast Growth Factor Receptor 3 R&#xE9;sultats de signalisation des d&#xE9;fauts dans la diff&#xE9;renciation cellulaire, mod&#xE9;lisation neuronale, et la d&#xE9;ficience auditive

Streichung des Fibroblasten-Wachstumsfaktor-Rezeptor 3 (Fgfr3) f&uuml;hrt zu H&ouml;rsch&auml;den bei M&auml;usen aufgrund von M&auml;ngeln bei der Entwicklung von Organ von Corti, das sensorische Epithel der Cochlea. Um die Rolle des FGFR3 in auditive Entwicklung zu untersuchen, wurden Cochleae Fgfr3(-/-) M&auml;use mit anatomische und physiologische Methoden untersucht. Streichung des Fgfr3 f&uuml;hrt zu ohne innere S&auml;ule Zellen und eine Zunahme der andere Zelltypen, was darauf hindeutet, dass FGFR3 Zelle Schicksal regelt. M&auml;ngel im &auml;u&szlig;eren Haarzelle Differenzierung wurden auch beobachtet und wahrscheinlich die wichtigste Grundlage f&uuml;r H&ouml;rverlust darstellen. Dar&uuml;ber hinaus wurden die Innervation M&auml;ngel mit &Auml;nderungen in der Anleitung Fasereigenschaften S&auml;ule Zellen erkannt. Um die Mechanismen, die die Auswirkungen des FGFR3 aufzukl&auml;ren, haben wir den Ausdruck des Bmp4, einem bekannten Ziel gepr&uuml;ft. Bmp4 wurde in Fgfr3(-/-) Cochleae erh&ouml;ht und exogene Knochen morphogenetische Protein 4 (BMP4) auf Cochlea Explantaten verursachte eine signifikante Zunahme der &auml;u&szlig;eren Haarzellen, schl&auml;gt den Fgf und Bmp Signalling Akt in die Cochlea Muster-Konzert.

Unterbrechung der Fibroblast Growth Factor Rezeptor 3 Signalisierung Ergebnisse in M&auml;ngel in zellul&auml;re Differenzierung, neuronale Musterbildung und H&ouml;rst&ouml;rungen.

Eliminazione del ricevitore di fattore di crescita dei fibroblasti 3 (Fgfr3) conduce all&#39;indebolimento dell&#39;udito nei topi a causa di difetti di sviluppo dell&#39;organo del Corti, l&#39;epitelio sensoriale della coclea. Per esaminare il ruolo di FGFR3 nello sviluppo uditivo, cochleae da Fgfr3(-/-) topi sono stati esaminati usando metodi anatomici e fisiologici. Eliminazione di Fgfr3 conduce all&#39;assenza di pilastro interno cellule e un aumento di altri tipi di cellule, suggerendo che FGFR3 regola il destino delle cellule. Difetti nella differenziazione esterna delle cellule dei capelli sono stati anche osservati e probabilmente rappresentano la base primaria per la perdita dell&#39;udito. Inoltre, difetti di innervazione sono stati rilevati coerente con i cambiamenti nelle propriet&agrave; orientamento fibre di cellule pilastro. Per delucidare i meccanismi alla base gli effetti di FGFR3, abbiamo esaminato l&#39;espressione di Bmp4, una destinazione conosciuta. Bmp4 era aumentato a Fgfr3(-/-) cochleae e applicazione esogena della proteina morfogenetica ossea 4 (BMP4) su espianti cocleare indotta da un aumento significativo delle cellule ciliate esterne, suggerendo l&#39;atto di segnalazione Fgf e Bmp in concerto a motivo della coclea.

Interruzione del fibroblasto growth factor receptor 3 segnalazione risultati in difetto di differenziazione cellulare, neuronale patterning e udito.

&#x7DDA;&#x7DAD;&#x82BD;&#x7D30;&#x80DE;&#x5897;&#x6B96;&#x56E0;&#x5B50;&#x53D7;&#x5BB9;&#x4F53;3&#xFF08;FGFR3&#xFF09;&#x306E;&#x6B20;&#x5931;&#x306F;&#x3001;&#x30B3;&#x30EB;&#x30C1;&#x3001;&#x8778;&#x725B;&#x306E;&#x611F;&#x899A;&#x4E0A;&#x76AE;&#x5668;&#x5B98;&#x306E;&#x767A;&#x9054;&#x306E;&#x6B20;&#x9665;&#x306B;&#x8D77;&#x56E0;&#x3059;&#x308B;&#x30DE;&#x30A6;&#x30B9;&#x306E;&#x8074;&#x899A;&#x969C;&#x5BB3;&#x306B;&#x3064;&#x306A;&#x304C;&#x308A;&#x307E;&#x3059;&#x3002;&#x8074;&#x899A;&#x958B;&#x767A;&#x306B;&#x304A;&#x3051;&#x308B;FGFR3&#x306E;&#x5F79;&#x5272;&#x3092;&#x8ABF;&#x3079;&#x308B;&#x305F;&#x3081;&#x3001;FGFR3&#x304B;&#x3089;&#x8778;&#x725B;&#xFF08; -  /  - &#xFF09;&#x30DE;&#x30A6;&#x30B9;&#x306F;&#x89E3;&#x5256;&#x5B66;&#x7684;&#x304A;&#x3088;&#x3073;&#x751F;&#x7406;&#x5B66;&#x7684;&#x65B9;&#x6CD5;&#x3092;&#x7528;&#x3044;&#x3066;&#x691C;&#x8A0E;&#x3057;&#x305F;&#x3002; FGFR3&#x306E;&#x5185;&#x5074;&#x306E;&#x67F1;&#x7D30;&#x80DE;&#x306E;&#x975E;&#x5B58;&#x5728;&#x4E0B;&#x306B;&#x3001;&#x30EA;&#x30FC;&#x30C9;&#x3068;&#x4ED6;&#x306E;&#x30BF;&#x30A4;&#x30D7;&#x306E;&#x7D30;&#x80DE;&#x306E;&#x5897;&#x52A0;&#x306E;&#x524A;&#x9664;&#x306F;&#x3001;FGFR3&#x306F;&#x7D30;&#x80DE;&#x306E;&#x904B;&#x547D;&#x3092;&#x5236;&#x5FA1;&#x3059;&#x308B;&#x3053;&#x3068;&#x3092;&#x793A;&#x5506;&#x3057;&#x3066;&#x3044;&#x308B;&#x3002;&#x5916;&#x6709;&#x6BDB;&#x7D30;&#x80DE;&#x306E;&#x5206;&#x5316;&#x306E;&#x6B20;&#x9665;&#x3082;&#x89B3;&#x5BDF;&#x3057;&#x3001;&#x304A;&#x305D;&#x3089;&#x304F;&#x8074;&#x529B;&#x640D;&#x5931;&#x306E;&#x4E3B;&#x306A;&#x57FA;&#x790E;&#x3092;&#x8868;&#x3057;&#x3066;&#x3044;&#x305F;&#x3002;&#x3055;&#x3089;&#x306B;&#x3001;&#x795E;&#x7D4C;&#x652F;&#x914D;&#x306E;&#x6B20;&#x9665;&#x304C;&#x67F1;&#x7D30;&#x80DE;&#x306E;&#x7E4A;&#x7DAD;&#x6307;&#x5C0E;&#x7279;&#x6027;&#x306E;&#x5909;&#x5316;&#x3068;&#x4E00;&#x81F4;&#x3057;&#x3066;&#x691C;&#x51FA;&#x3055;&#x308C;&#x305F;&#x3002; FGFR3&#x306E;&#x5F71;&#x97FF;&#x306E;&#x30E1;&#x30AB;&#x30CB;&#x30BA;&#x30E0;&#x3092;&#x89E3;&#x660E;&#x3059;&#x308B;&#x305F;&#x3081;&#x306B;&#x3001;&#x6211;&#x3005;&#x306F;BMP4&#x3001;&#x77E5;&#x3089;&#x308C;&#x3066;&#x3044;&#x308B;&#x30BF;&#x30FC;&#x30B2;&#x30C3;&#x30C8;&#x306E;&#x767A;&#x73FE;&#x3092;&#x8ABF;&#x3079;&#x305F;&#x3002; &#xFF08; -  /  - &#xFF09;BMP4&#x306F;&#x3001;FGFR3&#x306B;&#x5897;&#x52A0;&#x3057;&#x305F;&#x8778;&#x725B;&#x3068;&#x8778;&#x725B;&#x5916;&#x690D;&#x7247;&#x306E;&#x4E0A;&#x306B;&#x9AA8;&#x5F62;&#x6210;&#x30BF;&#x30F3;&#x30D1;&#x30AF;&#x8CEA;4&#xFF08;BMP4&#xFF09;&#x306E;&#x5916;&#x56E0;&#x6027;&#x306E;&#x30A2;&#x30D7;&#x30EA;&#x30B1;&#x30FC;&#x30B7;&#x30E7;&#x30F3;&#x3067;&#x306F;&#x3001;&#x30D1;&#x30BF;&#x30FC;&#x30F3;&#x8778;&#x725B;&#x306B;&#x30B3;&#x30F3;&#x30B5;&#x30FC;&#x30C8;&#x3067;FGF&#x3068;BMP&#x30B7;&#x30B0;&#x30CA;&#x30EB;&#x4F1D;&#x9054;&#x884C;&#x70BA;&#x3092;&#x793A;&#x5506;&#x3057;&#x3001;&#x5916;&#x6709;&#x6BDB;&#x7D30;&#x80DE;&#x306E;&#x6709;&#x610F;&#x306A;&#x5897;&#x52A0;&#x3092;&#x8A98;&#x767A;&#x3057;&#x305F;&#x3002;

&#x7DDA;&#x7DAD;&#x82BD;&#x7D30;&#x80DE;&#x6210;&#x9577;&#x56E0;&#x5B50;&#x53D7;&#x5BB9;&#x4F53;&#x306E;&#x5206;&#x88C2;&#x7D30;&#x80DE;&#x306E;&#x5206;&#x5316;&#x3001;&#x795E;&#x7D4C;&#x30D1;&#x30BF;&#x30FC;&#x30CB;&#x30F3;&#x30B0;&#x3057;&#x3001;&#x8074;&#x899A;&#x969C;&#x5BB3;&#x306E;&#x6B20;&#x9665;&#x306E;3&#x30B7;&#x30B0;&#x30CA;&#x30EA;&#x30F3;&#x30B0;&#x7D50;&#x679C;

&#xC12C;&#xC720; &#xC544; &#xC138;&#xD3EC; &#xC131;&#xC7A5; &#xC778;&#xC790; &#xC218;&#xC6A9; &#xCCB4; 3 (Fgfr3) &#xC0AD;&#xC81C; &#xB9C8;&#xC6B0;&#xC2A4; &#xAC1C;&#xBC1C; &#xC7A5;&#xAE30;&#xC758; &#xCF54;&#xD2B8;, &#xB2EC;&#xD33D;&#xC774; &#xAD00;&#xC758; &#xAC10;&#xAC01; &#xC0C1;&#xD53C;&#xC758; &#xACB0;&#xD568; &#xB54C;&#xBB38;&#xC5D0; &#xCCAD;&#xAC01; &#xC7A5;&#xC560;&#xB97C; &#xB9AC;&#xB4DC;. &#xCCAD;&#xAC01; &#xAC1C;&#xBC1C; FGFR3 &#xC5ED;&#xD560;&#xC744; &#xAC80;&#xC0AC; &#xD558;&#xB824;&#xBA74; Fgfr3(-/-) &#xB9C8;&#xC6B0;&#xC2A4;&#xC5D0;&#xC11C; cochleae &#xD574; &#xBD80;&#xC640; &#xC0DD;&#xB9AC; &#xC801;&#xC778; &#xBC29;&#xBC95;&#xC744; &#xC0AC;&#xC6A9; &#xD558; &#xC5EC; &#xC870;&#xC0AC; &#xD588;&#xB2E4;. Fgfr3 &#xC0AD;&#xC81C; &#xB0B4;&#xBD80; &#xAE30;&#xB465; &#xC138;&#xD3EC;&#xC640; &#xB2E4;&#xB978; &#xC138;&#xD3EC; &#xC720;&#xD615;, FGFR3 &#xC138;&#xD3EC; &#xC6B4;&#xBA85; &#xC870;&#xC808; &#xC81C;&#xC548; &#xC99D;&#xAC00;&#xC758; &#xBD80;&#xC7AC;&#xAC00; &#xB048;&#xB2E4;. &#xC678;&#xBD80; &#xBA38;&#xB9AC; &#xC138;&#xD3EC; &#xBD84;&#xD654;&#xC5D0; &#xAD00;&#xCC30; &#xD588;&#xB2E4; &#xACE0; &#xC544;&#xB9C8; &#xCCAD;&#xB825; &#xC190;&#xC2E4;&#xC5D0; &#xB300; &#xD55C; &#xAE30;&#xBCF8; &#xBC14;&#xD0D5;&#xC744; &#xB098;&#xD0C0;&#xB0C5;&#xB2C8;&#xB2E4;. &#xB610;&#xD55C;, &#xACB0;&#xD568;&#xC774; innervation &#xAE30;&#xB465; &#xC140; &#xC12C;&#xC720; &#xC9C0;&#xB3C4; &#xC18D;&#xC131;&#xC758; &#xBCC0;&#xD654;&#xC5D0; &#xB530;&#xB77C; &#xC77C;&#xAD00; &#xB41C; &#xBC1C;&#xACAC; &#xB418;&#xC5C8;&#xC2B5;&#xB2C8;&#xB2E4;. FGFR3 &#xD6A8;&#xACFC; &#xAE30;&#xBCF8; &#xBA54;&#xCEE4;&#xB2C8;&#xC998;&#xC744; &#xBA85;&#xB8CC; &#xD558; &#xC6B0;&#xB9AC; Bmp4, &#xC54C;&#xB824;&#xC9C4;&#xB41C; &#xB300;&#xC0C1;&#xC758; &#xC2DD;&#xC744; &#xC870;&#xC0AC; &#xD588;&#xB2E4;. Bmp4 Fgfr3(-/-) cochleae&#xC5D0; &#xC788;&#xB294; &#xC99D;&#xAC00; &#xBC0F; exogenous &#xBF08; &#xC804;&#xCCB4;&#xC801; &#xB2E8;&#xBC31;&#xC9C8; 4 (BMP4) &#xC778;&#xACF5; &#xC640;&#xC6B0; explants&#xC5D0; &#xC801;&#xC6A9; &#xC678;&#xBD80; &#xC138;&#xD3EC;, &#xB2EC;&#xD33D;&#xC774; &#xAD00;&#xC744; &#xD328;&#xD134;&#xD654; &#xD558;&#xB824;&#xBA74; &#xCF58;&#xC11C;&#xD2B8;&#xC5D0; Fgf&#xC640; Bmp &#xC2E0;&#xD638; &#xBC95; &#xC81C;&#xC548;&#xC5D0; &#xC0C1;&#xB2F9;&#xD55C; &#xC99D;&#xAC00; &#xC720;&#xBC1C;.

&#xC12C;&#xC720; &#xC544; &#xC138;&#xD3EC; &#xC131;&#xC7A5; &#xC778;&#xC790; &#xC218;&#xC6A9; &#xCCB4; 3 &#xC2E0;&#xD638; &#xACB0;&#xACFC; &#xC138;&#xD3EC; &#xBD84;&#xD654;, &#xC2E0;&#xACBD; &#xD328;&#xD134;&#xD654; &#xBC0F; &#xCCAD;&#xAC01; &#xC7A5;&#xC560;&#xC5D0; &#xACB0;&#xD568;&#xC758; &#xC911;&#xB2E8;.

Supresi&#xF3;n del receptor del factor de crecimiento de fibroblastos 3 (FGFR3) conduce a la discapacidad auditiva en los ratones debido a defectos en el desarrollo del &#xF3;rgano de Corti, el epitelio sensorial de la c&#xF3;clea. Para examinar el papel de FGFR3 en el desarrollo auditivo, c&#xF3;cleas de FGFR3 (- / -) ratones fueron examinados mediante m&#xE9;todos anat&#xF3;micos y fisiol&#xF3;gicos. La eliminaci&#xF3;n de FGFR3 conduce a la ausencia de c&#xE9;lulas pilar interior y un aumento de otros tipos de c&#xE9;lulas, lo que sugiere que el FGFR3 regula el destino celular. Los defectos en la diferenciaci&#xF3;n de las c&#xE9;lulas pilosas externas, tambi&#xE9;n se observaron y, probablemente, representan la base principal para la p&#xE9;rdida de audici&#xF3;n. Por otra parte, los defectos de la inervaci&#xF3;n se detectaron en consonancia con los cambios en las propiedades de orientaci&#xF3;n de fibra de c&#xE9;lulas pilar. Para dilucidar los mecanismos subyacentes a los efectos de FGFR3, hemos examinado la expresi&#xF3;n de Bmp4, un objetivo conocido. Bmp4 se increment&#xF3; en FGFR3 (- / -) c&#xF3;cleas, y la aplicaci&#xF3;n ex&#xF3;gena de la prote&#xED;na morfogen&#xE9;tica &#xF3;sea 4 (BMP4) en explantes cocleares indujo un aumento significativo en las c&#xE9;lulas ciliadas externas, lo que sugiere la FGF y la se&#xF1;alizaci&#xF3;n de BMP act&#xFA;an en concierto con el patr&#xF3;n de la c&#xF3;clea.

La interrupci&#xF3;n del receptor del factor de crecimiento fibrobl&#xE1;stico 3 Resultados de se&#xF1;alizaci&#xF3;n de defectos en la diferenciaci&#xF3;n celular, los patrones neuronales, y la Discapacidad Auditiva

Sox2 &#x662F;&#x53D1;&#x5C55;&#x5185;&#x8033; prosensory &#x57DF;&#x7684;&#x6700;&#x65E9;&#x6807;&#x5FD7;&#x4E4B;&#x4E00;&#x7684;&#x9AD8;&#x673A;&#x52A8;&#x6027;&#x8F6C;&#x5F55;&#x56E0;&#x5B50;&#x3002;&#x5728;&#x4EBA;&#x7C7B;&#x4E2D;&#xFF0C;SOX2 &#x57FA;&#x56E0;&#x7A81;&#x53D8;&#x5BFC;&#x81F4;&#x7684;&#x795E;&#x7ECF;&#x6027;&#x542C;&#x529B;&#x635F;&#x5931;&#xFF0C;&#x635F;&#x5931;&#x7684;&#x5C0F;&#x9F20;&#x529F;&#x80FD;&#x7684;&#x7814;&#x7A76;&#x8868;&#x660E; Sox2 &#x662F;&#x9700;&#x5728;&#x8033;&#x8717;&#x4E2D;&#x7684; prosensory &#x5F62;&#x6210;&#x7684;&#x3002;&#x4E0D;&#x8FC7;&#xFF0C;&#x5C1A;&#x672A;&#x786E;&#x5B9A; Sox2 &#x7684;&#x5177;&#x4F53;&#x4F5C;&#x7528;&#x3002;&#x5728;&#x8FD9;&#x91CC;&#x6211;&#x4EEC;&#x8BF4;&#x660E; Sox2 &#x8DDF; Atoh1&#xFF0C;&#x6BDB;&#x7EC6;&#x80DE;&#x53D1;&#x5C55;&#x6240;&#x9700;&#x7684; bHLH &#x86CB;&#x767D;&#x4E0E;&#x5BF9;&#x7ACB;&#x5173;&#x7CFB;&#x7684; prosensory &#x57DF;&#x5F62;&#x6210;&#x7684;&#x4E00;&#x4E2A;&#x65E9;&#x671F;&#x8BB8;&#x53EF;&#x56E0;&#x7D20;&#x4F5C;&#x4E3A;&#x52A8;&#x6001;&#x4F5C;&#x7528;&#x3002;&#x6211;&#x4EEC;&#x8BC1;&#x660E;&#xFF0C;&#x51CF;&#x5C11; Sox2 &#x7ED3;&#x679C;&#x65E9;&#x719F;&#x7684;&#x6BDB;&#x7EC6;&#x80DE;&#x5206;&#x5316;&#x8FC7;&#x7A0B;&#x4E2D;&#x7684;&#x6C34;&#x5E73;&#x53CA;&#x4EE5;&#x4E0A;&#x901A;&#x8FC7; Sox2 &#x548C; bHLH &#x5206;&#x5B50; Atoh1 &#x62EE;&#x6297;&#x76F8;&#x4E92;&#x4F5C;&#x7528;&#x4ECB;&#x5BFC;&#x7684;&#x5185;&#x6BDB;&#x7EC6;&#x80DE;&#x751F;&#x4EA7;&#x548C;&#x8FD9;&#x4E9B;&#x5F71;&#x54CD;&#x5F88;&#x6709;&#x53EF;&#x80FD;&#x3002;&#x6211;&#x4EEC;&#x4F7F;&#x7528;&#x589E;&#x76CA;&#x548C;&#x635F;&#x5931;-&#x7684;-&#x529F;&#x80FD;&#x5B9E;&#x9A8C;&#x63D0;&#x4F9B;&#x8D1F;&#x8D23;&#x7684;&#x4EBA;&#x5DE5;&#x8033;&#x8717; prosensory &#x57DF;&#x5F62;&#x6210;&#x7684;&#x5206;&#x5B50;&#x901A;&#x8DEF;&#x7684;&#x8BC1;&#x636E;&#x3002;Sox2 &#x8868;&#x8FBE; Notch &#x4FE1;&#x53F7;&#x548C; Prox1&#xFF0C;&#x540C;&#x6E90;&#x76D2;&#x57FA;&#x56E0;&#x8F6C;&#x5F55;&#x56E0;&#x5B50;&#x4FC3;&#x8FDB;&#x3001; Sox2 &#x4E0B;&#x6E38;&#x76EE;&#x6807;&#x3002;&#x8FD9;&#x4E9B;&#x7ED3;&#x679C;&#x4E2D;&#x7684;&#x53D1;&#x5C55;&#x3001; &#x89C4;&#x8303;&#x4E0E;&#x5185;&#x8033;&#x8717;&#x611F;&#x89C9;&#x7EC6;&#x80DE;&#x7EF4;&#x62A4;&#x4E3A; Sox2 &#x5C55;&#x793A;&#x5173;&#x952E;&#x548C;&#x5404;&#x79CD;&#x4E0D;&#x540C;&#x7684;&#x89D2;&#x8272;&#x3002;

Sox2 &#x4FE1;&#x53F7;&#x5728; prosensory &#x57DF;&#x89C4;&#x8303;&#x548C;&#x968F;&#x540E;&#x7684;&#x5934;&#x53D1;&#x7EC6;&#x80DE;&#x5206;&#x5316;&#x7684;&#x53D1;&#x5C55;&#x4E2D;&#x56FD;&#x5BB6;&#x7684;&#x8033;&#x8717;&#x3002;

Sox2 is a high-mobility transcription factor that is one of the earliest markers of developing inner ear prosensory domains. In humans, mutations in SOX2 cause sensorineural hearing loss and a loss of function study in mice showed that Sox2 is required for prosensory formation in the cochlea. However, the specific roles of Sox2 have not been determined. Here we illustrate a dynamic role of Sox2 as an early permissive factor in prosensory domain formation followed by a mutually antagonistic relationship with Atoh1, a bHLH protein necessary for hair cell development. We demonstrate that decreased levels of Sox2 result in precocious hair cell differentiation and an over production of inner hair cells and that these effects are likely mediated through an antagonistic interaction between Sox2 and the bHLH molecule Atoh1. Using gain- and loss-of-function experiments we provide evidence for the molecular pathway responsible for the formation of the cochlear prosensory domain. Sox2 expression is promoted by Notch signaling and Prox1, a homeobox transcription factor, is a downstream target of Sox2. These results demonstrate crucial and diverse roles for Sox2 in the development, specification, and maintenance of sensory cells within the cochlea.

Sox2 signaling in prosensory domain specification and subsequent hair cell differentiation in the developing cochlea.

Sox2 est un facteur de transcription &#xE0; haute mobilit&#xE9; qui est l&#x26;#39;un des premiers marqueurs de d&#xE9;veloppement internes domaines prosensory oreille. Chez l&#x26;#39;homme, des mutations dans la cause la perte auditive neurosensorielle SOX2 et une perte de fonction dans l&#x26;#39;&#xE9;tude des souris ont montr&#xE9; que Sox2 est n&#xE9;cessaire &#xE0; la formation prosensory dans la cochl&#xE9;e. Cependant, les r&#xF4;les sp&#xE9;cifiques de Sox2 n&#x26;#39;ont pas &#xE9;t&#xE9; d&#xE9;termin&#xE9;es. Ici, nous illustrons un r&#xF4;le dynamique de Sox2 comme un facteur permissif au d&#xE9;but de la formation de domaine prosensory suivie d&#x26;#39;une relation mutuellement antagoniste avec Atoh1, une prot&#xE9;ine bHLH n&#xE9;cessaire pour le d&#xE9;veloppement des cellules cili&#xE9;es. Nous d&#xE9;montrons que les niveaux ont diminu&#xE9; de r&#xE9;sultat Sox2 dans la diff&#xE9;renciation des cellules cili&#xE9;es pr&#xE9;coce et une surproduction de cellules cili&#xE9;es internes et que ces effets sont probablement m&#xE9;di&#xE9;e par une interaction antagoniste entre Sox2 et la mol&#xE9;cule bHLH Atoh1. Utilisation de gain et la perte de fonction des exp&#xE9;riences que nous apporter la preuve de la voie mol&#xE9;culaire responsable de la formation du domaine cochl&#xE9;aire prosensory. Expression Sox2 est favoris&#xE9;e par la signalisation Notch et Prox1, un facteur de transcription &#xE0; hom&#xE9;obo&#xEE;te, est une cible en aval de Sox2. Ces r&#xE9;sultats d&#xE9;montrent un r&#xF4;le crucial et diversifi&#xE9;e pour Sox2 dans le d&#xE9;veloppement, la sp&#xE9;cification et l&#x26;#39;entretien des cellules sensorielles dans la cochl&#xE9;e.

Sox2 signalisation dans la sp&#xE9;cification de domaine et Prosensory Apr&#xE8;s diff&#xE9;renciation des cellules cili&#xE9;es de la cochl&#xE9;e en d&#xE9;veloppement

Sox2 ist ein hoch-Mobilit&auml;t Transkriptionsfaktor, der die fr&uuml;heste Marker Innenohr Prosensory Dom&auml;nen zu entwickeln ist. Beim Menschen Mutationen im SOX2 verursachen Schallempfindungs-Schwerh&ouml;rigkeit und ein Verlust der Funktion Studie an M&auml;usen zeigten, dass Sox2 f&uuml;r Prosensory-Formation in der Cochlea erforderlich ist. Jedoch wurden die spezifischen Rollen von Sox2 nicht bestimmt. Hier zeigen wir eine dynamische Rolle der Sox2 als fr&uuml;he permissive Faktor in Prosensory Dom&auml;ne-Formation, gefolgt von einem gegenseitig antagonistischen Verh&auml;ltnis mit Atoh1, ein bHLH Protein f&uuml;r Haarzelle Entwicklung notwendig. Wir demonstrieren, die verringerte Niveaus der Sox2 Ergebnis bei fr&uuml;hreifen Haarzelle Differenzierung und ein &uuml;ber Produktion von innerer Haarzellen und, dass diese Effekte d&uuml;rften durch eine antagonistische Interaktion zwischen Sox2 und das bHLH-Molek&uuml;l Atoh1 vermittelt. Mit Gewinn - und Verlust-von-Funktion Experimente bieten wir Beweise f&uuml;r die molekulare Pathway verantwortlich f&uuml;r die Bildung der Cochlea Prosensory Dom&auml;ne. Sox2 Expression von Notch Signal- und Prox1, ein Homeobox &Uuml;bertragungfaktor gef&ouml;rdert wird, ist ein nachgeschalteter Ziel von Sox2. Diese Ergebnisse zeigen wichtige und vielf&auml;ltige Rollen f&uuml;r Sox2 in der Entwicklung, der Spezifikation und der Wartung von Sinneszellen in der Cochlea.

Sox2 signalisieren in Prosensory Dom&auml;ne Spezifikation und nachfolgende Haarzelle Differenzierung der entwickelnden Cochlea.

SOX2 &egrave; un fattore di trascrizione di alto-mobilit&agrave; che &egrave; uno dei primi marcatori di sviluppo dell&#39;orecchio interno prosensory domini. Nell&#39;uomo, mutazioni in SOX2 causano la perdita dell&#39;udito neurosensoriale e una perdita di funzione studio nei topi ha mostrato che Sox2 &egrave; necessaria per la formazione prosensory nella coclea. Tuttavia, non sono stati determinati i ruoli specifici di Sox2. Illustriamo qui un ruolo dinamico di Sox2 come fattore permissivo precoce formazione di dominio prosensory seguita da un rapporto reciprocamente antagonistico con Atoh1, una proteina bHLH necessaria per lo sviluppo delle cellule dei capelli. Dimostriamo che sono diminuiti livelli di risultato Sox2 nel differenziamento delle cellule dei capelli precoce e una produzione di cellule ciliate interne e che questi effetti sono probabilmente mediati attraverso un&#39;interazione antagonistica tra Sox2 e la molecola bHLH Atoh1. Tramite esperimenti di guadagno e perdita-di-funzione ci forniscono la prova per il pathway molecolare responsabile della formazione del dominio prosensory cocleare. Espressione SOX2 &egrave; promosso da segnalazione Notch e Prox1, un fattore di trascrizione homeobox, &egrave; un bersaglio a valle di Sox2. Questi risultati dimostrano cruciali e diversi ruoli per Sox2 nello sviluppo, specifica e nella manutenzione delle cellule sensoriali all&#39;interno della coclea.

SOX2 segnalazione nel prosensory dominio disciplinare e differenziazione delle cellule dei capelli successive nella coclea in via di sviluppo.

Sox2&#x306F;&#x5185;&#x8033;prosensory&#x30C9;&#x30E1;&#x30A4;&#x30F3;&#x3092;&#x958B;&#x767A;&#x306E;&#x521D;&#x671F;&#x306E;&#x30DE;&#x30FC;&#x30AB;&#x30FC;&#x306E;&#x4E00;&#x3064;&#x3067;&#x3042;&#x308B;&#x9AD8;&#x6A5F;&#x52D5;&#x6027;&#x8EE2;&#x5199;&#x56E0;&#x5B50;&#x3067;&#x3042;&#x308B;&#x3002;&#x30D2;&#x30C8;&#x3067;&#x306F;&#x3001;SOX2&#x306E;&#x539F;&#x56E0;&#x611F;&#x97F3;&#x96E3;&#x8074;&#x3068;&#x30DE;&#x30A6;&#x30B9;&#x306E;&#x6A5F;&#x80FD;&#x7814;&#x7A76;&#x306E;&#x640D;&#x5931;&#x5909;&#x7570;&#x306F;&#x3001;&#x30EC;&#x30C8;&#x30ED;&#x30A6;&#x30A4;&#x30EB;&#x30B9;&#x30D9;&#x30AF;&#x30BF;&#x30FC;&#x306F;&#x3001;&#x8778;&#x725B;&#x306E;prosensory&#x5F62;&#x6210;&#x306E;&#x305F;&#x3081;&#x306B;&#x5FC5;&#x8981;&#x3068;&#x3055;&#x308C;&#x308B;&#x3053;&#x3068;&#x304C;&#x660E;&#x3089;&#x304B;&#x306B;&#x306A;&#x3063;&#x305F;&#x3002;&#x3057;&#x304B;&#x3057;&#x3001;Sox2&#x306E;&#x7279;&#x5B9A;&#x306E;&#x5F79;&#x5272;&#x304C;&#x6C7A;&#x5B9A;&#x3055;&#x308C;&#x3066;&#x3044;&#x306A;&#x3044;&#x3002;&#x3053;&#x3053;&#x3067;&#x306F;&#x3001;ATOH1&#x3001;&#x6709;&#x6BDB;&#x7D30;&#x80DE;&#x306E;&#x958B;&#x767A;&#x306B;&#x5FC5;&#x8981;&#x306A;bHLH&#x578B;&#x86CB;&#x767D;&#x8CEA;&#x3068;&#x76F8;&#x4E92;&#x306B;&#x6575;&#x5BFE;&#x95A2;&#x4FC2;&#x304C;&#x7D9A;&#x3044;prosensory&#x30C9;&#x30E1;&#x30A4;&#x30F3;&#x5F62;&#x6210;&#x306E;&#x521D;&#x671F;&#x6BB5;&#x968E;&#x3067;&#x5BDB;&#x5927;&#x306A;&#x56E0;&#x5B50;&#x3068;&#x3057;&#x3066;Sox2&#x306E;&#x52D5;&#x7684;&#x306A;&#x5F79;&#x5272;&#x3092;&#x793A;&#x3057;&#x3066;&#x3044;&#x307E;&#x3059;&#x3002;&#x79C1;&#x305F;&#x3061;&#x306F;&#x65E9;&#x719F;&#x6709;&#x6BDB;&#x7D30;&#x80DE;&#x306E;&#x5206;&#x5316;&#x3068;&#x5185;&#x6709;&#x6BDB;&#x7D30;&#x80DE;&#x306E;&#x4E0A;&#x306B;&#x751F;&#x7523;&#x306B;&#x3001;&#x3053;&#x308C;&#x3089;&#x306E;&#x52B9;&#x679C;&#x306F;&#x9AD8;&#x3044;Sox2&#x3001;&#x53CA;&#x3073;bHLH&#x578B;&#x5206;&#x5B50;ATOH1&#x306E;&#x9593;&#x306B;&#x62EE;&#x6297;&#x4F5C;&#x7528;&#x3092;&#x4ECB;&#x3057;&#x3066;&#x5A92;&#x4ECB;&#x3055;&#x308C;&#x3066;&#x3044;&#x308B;Sox2&#x306E;&#x7D50;&#x679C;&#x306E;&#x30EC;&#x30D9;&#x30EB;&#x3092;&#x6E1B;&#x5C11;&#x3055;&#x305B;&#x305F;&#x3053;&#x3068;&#x3092;&#x793A;&#x3057;&#x3066;&#x3044;&#x308B;&#x3002;&#x30B2;&#x30A4;&#x30F3;&#x304A;&#x3088;&#x3073;&#x6A5F;&#x80FD;&#x55AA;&#x5931;&#x5B9F;&#x9A13;&#x3092;&#x7528;&#x3044;&#x3066;&#x3001;&#x6211;&#x3005;&#x306F;&#x8778;&#x725B;prosensory&#x30C9;&#x30E1;&#x30A4;&#x30F3;&#x306E;&#x5F62;&#x6210;&#x306B;&#x95A2;&#x4E0E;&#x3059;&#x308B;&#x5206;&#x5B50;&#x7D4C;&#x8DEF;&#x306E;&#x8A3C;&#x62E0;&#x3092;&#x63D0;&#x4F9B;&#x3057;&#x3066;&#x3044;&#x307E;&#x3059;&#x3002; Sox2&#x306E;&#x767A;&#x73FE;&#x306F;Notch&#x30B7;&#x30B0;&#x30CA;&#x30EB;&#x3068;Prox1&#x3001;&#x30DB;&#x30E1;&#x30AA;&#x30DC;&#x30C3;&#x30AF;&#x30B9;&#x8EE2;&#x5199;&#x56E0;&#x5B50;&#x306B;&#x3088;&#x3063;&#x3066;&#x4FC3;&#x9032;&#x3055;&#x308C;&#x308B;&#x3001;Sox2&#x306E;&#x4E0B;&#x6D41;&#x6A19;&#x7684;&#x3067;&#x3042;&#x308B;&#x3002;&#x3053;&#x308C;&#x3089;&#x306E;&#x7D50;&#x679C;&#x306F;&#x3001;&#x8778;&#x725B;&#x5185;&#x306E;&#x611F;&#x899A;&#x7D30;&#x80DE;&#x306E;&#x958B;&#x767A;&#x3001;&#x4ED5;&#x69D8;&#x3001;&#x30E1;&#x30F3;&#x30C6;&#x30CA;&#x30F3;&#x30B9;&#x306B;Sox2&#x306E;&#x305F;&#x3081;&#x306B;&#x91CD;&#x8981;&#x304B;&#x3064;&#x591A;&#x69D8;&#x306A;&#x5F79;&#x5272;&#x3092;&#x793A;&#x3057;&#x3066;&#x3044;&#x307E;&#x3059;&#x3002;

&#x958B;&#x767A;&#x8778;&#x725B;&#x5185;Prosensory&#x30C9;&#x30E1;&#x30A4;&#x30F3;&#x4ED5;&#x69D8;&#x3068;&#x305D;&#x306E;&#x5F8C;&#x306E;&#x9AEA;&#x306E;&#x7D30;&#x80DE;&#x306E;&#x5206;&#x5316;&#x306B;Sox2&#x306E;&#x30B7;&#x30B0;&#x30CA;&#x30EA;&#x30F3;&#x30B0;

Sox2 &#xB0B4;&#xAC00; prosensory &#xB3C4;&#xBA54;&#xC778; &#xAC1C;&#xBC1C;&#xC758; &#xCD08;&#xAE30; &#xD45C;&#xC2DD; &#xC911; &#xD558;&#xB098;&#xC785;&#xB2C8;&#xB2E4; &#xB192;&#xC740; &#xC774;&#xB3D9;&#xC131; &#xC804;&#xC0AC; &#xC694;&#xC18C; &#xC774;&#xB2E4;. &#xC778;&#xAC04;, sox2&#xC5D0; &#xB3CC;&#xC5F0;&#xBCC0;&#xC774; &#xB09C;&#xCCAD; &#xC6D0;&#xC778;&#xACFC; &#xC950;&#xC5D0; &#xAE30;&#xB2A5; &#xC5F0;&#xAD6C;&#xC758; &#xC190;&#xC2E4;&#xC744; &#xBCF4;&#xC5EC; Sox2 &#xB2EC;&#xD33D;&#xC774; &#xAD00;&#xC5D0; prosensory &#xD615;&#xC131;&#xC5D0; &#xD544;&#xC694;&#xD55C;. &#xADF8;&#xB7EC;&#xB098;, Sox2 &#xD2B9;&#xC815; &#xC5ED;&#xD560; &#xACB0;&#xC815; &#xB418;&#xC9C0; &#xC54A;&#xC740;. &#xC5EC;&#xAE30; &#xC6B0;&#xB9AC;&#xB294; prosensory &#xB3C4;&#xBA54;&#xC778; &#xD615;&#xC131; &#xB4A4;&#xC5D0; Atoh1, bHLH &#xB2E8;&#xBC31;&#xC9C8; &#xD5E4;&#xC5B4; &#xC140; &#xAC1C;&#xBC1C;&#xC5D0; &#xD544;&#xC694;&#xD55C; &#xC0C1;&#xD638; &#xB300;&#xB9BD; &#xAD00;&#xACC4;&#xC5D0;&#xC5D0;&#xC11C; &#xC774;&#xB978; &#xAD00;&#xB300; &#xD55C; &#xC694;&#xC18C;&#xB85C; sox2&#xC758; &#xB3D9;&#xC801; &#xC5ED;&#xD560;&#xC744; &#xBCF4;&#xC5EC; &#xC90D;&#xB2C8;&#xB2E4;. &#xC6B0;&#xB9AC;&#xB294; &#xC870; &#xC219;&#xD55C; &#xBA38;&#xB9AC; &#xC138;&#xD3EC; &#xBD84;&#xD654;&#xC5D0; Sox2 &#xACB0;&#xACFC;&#xC758; &#xC218;&#xC900; &#xBC0F; &#xC774;&#xC0C1; &#xAC10;&#xC18C; &#xBCF4;&#xC5EC; &#xB0B4;&#xBD80; &#xC138;&#xD3EC;&#xC758; &#xC0DD;&#xC0B0; &#xADF8;&#xB9AC;&#xACE0; &#xC774;&#xB7EC;&#xD55C; &#xD6A8;&#xACFC; &#xAC00;&#xB2A5;&#xC131;&#xC774; sox2&#xC640; Atoh1 bHLH &#xBD84;&#xC790; &#xAC04;&#xC758; &#xB300;&#xB9BD; &#xC0C1;&#xD638; &#xC791;&#xC6A9;&#xC744; &#xD1B5;&#xD574; &#xC911;&#xC7AC;. &#xC774;&#xB4DD; &#xBC0F; &#xC190;&#xC2E4;-&#xC758;-&#xAE30;&#xB2A5; &#xC2E4;&#xD5D8;&#xC744; &#xC0AC;&#xC6A9; &#xD558; &#xC5EC; &#xC778;&#xACF5; &#xC640;&#xC6B0; prosensory &#xB3C4;&#xBA54;&#xC778;&#xC758; &#xD615;&#xC131;&#xC744; &#xB2F4;&#xB2F9; &#xD558;&#xB294; &#xBD84;&#xC790; &#xACBD;&#xB85C; &#xB300; &#xD55C; &#xC99D;&#xAC70;&#xB97C; &#xC81C;&#xACF5; &#xD569;&#xB2C8;&#xB2E4;. Sox2 &#xC2DD; &#xB178;&#xCE58; &#xC2E0;&#xD638; &#xBC0F; Prox1, homeobox &#xC804;&#xC0AC; &#xC778;&#xC790;&#xC5D0; &#xC758;&#xD574; &#xCD94;&#xC9C4;, sox2&#xC758; &#xB2E4;&#xC6B4;&#xC2A4;&#xD2B8;&#xB9BC; &#xB300;&#xC0C1;&#xC785;&#xB2C8;&#xB2E4;. &#xC774;&#xB7EC;&#xD55C; &#xACB0;&#xACFC; sox2&#xC5D0; &#xB300; &#xD55C; &#xAC1C;&#xBC1C; &#xC0AC;&#xC591;&#xACFC; &#xB2EC;&#xD33D;&#xC774; &#xAD00; &#xB0B4;&#xC758; &#xAC10;&#xAC01; &#xC138;&#xD3EC;&#xC758; &#xC720;&#xC9C0;&#xC5D0; &#xB9E4;&#xC6B0; &#xC911;&#xC694; &#xD558; &#xACE0; &#xB2E4;&#xC591; &#xD55C; &#xC5ED;&#xD560;&#xC744; &#xBCF4;&#xC5EC; &#xC90D;&#xB2C8;&#xB2E4;.

Sox2 prosensory &#xB3C4;&#xBA54;&#xC778; &#xC0AC;&#xC591; &#xBC0F; &#xAC1C;&#xBC1C; &#xB2EC;&#xD33D;&#xC774; &#xAD00;&#xC5D0;&#xC11C; &#xD6C4;&#xC18D; &#xBA38;&#xB9AC; &#xC138;&#xD3EC; &#xBD84;&#xD654; &#xC2E0;&#xD638;&#xC785;&#xB2C8;&#xB2E4;.

Sox2 es un factor de transcripci&#xF3;n de alta movilidad, que es uno de los marcadores m&#xE1;s tempranos del desarrollo de los dominios internos prosensoriales o&#xED;do. En los seres humanos, las mutaciones en la p&#xE9;rdida de audici&#xF3;n neurosensorial SOX2 causa y una p&#xE9;rdida de funci&#xF3;n estudio en ratones demostr&#xF3; que Sox2 se requiere para la formaci&#xF3;n de prosensorial en la c&#xF3;clea. Sin embargo, las funciones espec&#xED;ficas de Sox2 no se han determinado. Aqu&#xED; ilustramos un papel din&#xE1;mico de Sox2 como un factor en la formaci&#xF3;n temprana permisiva de dominio prosensorial seguido por una relaci&#xF3;n mutuamente antagonista con Atoh1, una prote&#xED;na necesaria para el desarrollo bHLH de las c&#xE9;lulas ciliadas. Se demuestra que la disminuci&#xF3;n de los niveles de resultado Sox2 en la diferenciaci&#xF3;n precoz de c&#xE9;lulas de pelo y una producci&#xF3;n excesiva de las c&#xE9;lulas ciliadas internas y que estos efectos son probablemente mediado por una interacci&#xF3;n antag&#xF3;nica entre Sox2 y la mol&#xE9;cula bHLH Atoh1. Utilizando experimentos de ganancia y la p&#xE9;rdida de la funci&#xF3;n de aportar pruebas para la ruta molecular responsable de la formaci&#xF3;n del dominio prosensorial coclear. La expresi&#xF3;n de Sox2 es promovido por la se&#xF1;alizaci&#xF3;n de Notch y PROX1, un factor de transcripci&#xF3;n homeobox, ser&#xE1; un objetivo de Sox2. Estos resultados demuestran un papel crucial y diversa de Sox2 en el desarrollo, la especificaci&#xF3;n, y el mantenimiento de las c&#xE9;lulas sensoriales de la c&#xF3;clea.

Sox2 de se&#xF1;alizaci&#xF3;n en la especificaci&#xF3;n de dominio prosensorial y posterior diferenciaci&#xF3;n de las c&#xE9;lulas ciliadas de la c&#xF3;clea en desarrollo

In mammals, auditory perception is initially mediated through sensory cells located in a rigorously patterned mosaic of unique cell types located within the coiled cochlea. Identification of the factors that direct multipotent progenitor cells to develop as each of these specialized cell types has the potential to enhance our understanding of the development of the auditory system and to identify potential targets for regenerative therapies. Recent results have identified specific signaling molecules and pathways, including Notch, Hedgehog, Sox2 and Fgfs, that guide progenitor cells to develop first as a sensory precursor, referred to as a prosensory cell, and subsequently as one of the specialized cell types within the sensory mosaic.

Building the world's best hearing aid; regulation of cell fate in the cochlea.

A significant proportion of hearing loss and deafness is caused by defects in the structure or function of cells within the organ of Corti. Identification of the molecular factors that regulate the development of this structure should provide valuable insights regarding inner ear formation and the signaling pathways that underlie congenital auditory deficits. In addition, targeted modulation of these same factors could be developed as therapies for hair cell regeneration.

Regulation of cell fate and patterning in the developing mammalian cochlea.

In the cochlea, spiral ganglion neurons play a critical role in hearing as they form the relay between mechanosensory hair cells in the inner ear and cochlear nuclei in the brainstem. The proneural basic helix-loop-helix transcription factors Neurogenin1 (Neurog1) and NeuroD1 have been shown to be essential for the development of otocyst-derived inner ear sensory neurons. Here, we show neural competence of nonsensory epithelial cells in the cochlea, as ectopic expression of either Neurog1 or NeuroD1 results in the formation of neuronal cells. Since the high-mobility-group type transcription factor Sox2, which is also known to play a role in neurogenesis, is expressed in otocyst-derived neural precursor cells and later in the spiral ganglion neurons along with Neurog1 and NeuroD1, we used both gain- and loss-of-function experiments to examine the role of Sox2 in spiral ganglion neuron formation. We demonstrate that overexpression of Sox2 results in the production of neurons, suggesting that Sox2 is sufficient for the induction of neuronal fate in nonsensory epithelial cells. Furthermore, spiral ganglion neurons are absent in cochleae from Sox2(Lcc/Lcc) mice, indicating that Sox2 is also required for neuronal formation in the cochlea. Our results indicate that Sox2, along with Neurog1 and NeuroD1, are sufficient to induce a neuronal fate in nonsensory regions of the cochlea. Finally, we demonstrate that nonsensory cells within the cochlea retain neural competence through at least the early postnatal period.

Sox2 induces neuronal formation in the developing mammalian cochlea.

Cluster of differentiation antigens (CD proteins) are classically used as immune cell markers. However, their expression within the inner ear is still largely undefined. In this study, we explored the possibility that specific CD proteins might be useful for defining inner ear cell populations. mRNA expression profiling of microdissected auditory and vestibular sensory epithelia revealed 107 CD genes as expressed in the early postnatal mouse inner ear. The expression of 68 CD genes was validated with real-time RT-PCR using RNA extracted from microdissected sensory epithelia of cochleae, utricles, saccules, and cristae of newborn mice. Specifically, CD44 was identified as preferentially expressed in the auditory sensory epithelium. Immunohistochemistry revealed that within the early postnatal organ of Corti, the expression of CD44 is restricted to outer pillar cells. In order to confirm and expand this finding, we characterized the expression of CD44 in two different strains of mice with loss- and gain-of-function mutations in Fgfr3 which encodes a receptor for FGF8 that is essential for pillar cell development. We found that the expression of CD44 is abolished from the immature pillar cells in homozygous Fgfr3 knockout mice. In contrast, both the outer pillar cells and the aberrant Deiters' cells in the Fgfr3 ( P244R/ ) (+) mice express CD44. The deafness phenotype segregating in DFNB51 families maps to a linkage interval that includes CD44. To study the potential role of CD44 in hearing, we characterized the auditory system of CD44 knockout mice and sequenced the entire open reading frame of CD44 of affected members of DFNB51 families. Our results suggest that CD44 does not underlie the deafness phenotype of the DFNB51 families. Finally, our study reveals multiple potential new cell type-specific markers in the mouse inner ear and identifies a new marker for outer pillar cells.

CD44 is a marker for the outer pillar cells in the early postnatal mouse inner ear.

The canonical Wnt/β-catenin signaling pathway is known to play crucial roles in organogenesis by regulating both proliferation and differentiation. In the inner ear, this pathway has been shown to regulate the size of the otic placode from which the cochlea will arise; however, direct activity of canonical Wnt signaling as well as its function during cochlear mechanosensory hair cell development had yet to be identified. Using TCF/Lef:H2B-GFP reporter mice and transfection of an independent TCF/Lef reporter construct, we describe the pattern of canonical Wnt activity in the developing mouse cochlea. We show that prior to terminal mitosis, canonical Wnt activity is high in early prosensory cells from which hair cells and support cells will differentiate, and activity becomes reduced as development progresses. Using an in vitro model we demonstrate that Wnt/β-catenin signaling regulates both proliferation and hair cell differentiation within the developing cochlear duct. Inhibition of Wnt/β-catenin signaling blocks proliferation during early mitotic phases of development and inhibits hair cell formation in the differentiating organ of Corti. Conversely, activation increases the number of hair cells that differentiate and induces proliferation in prosensory cells, causing an expansion of the Sox2-positive prosensory domain. We further demonstrate that the induced proliferation of Sox2-positive cells may be mediated by the cell cycle regulator cyclin D1. Lastly, we provide evidence that the mitotic Sox2-positive cells are competent to differentiate into hair cells. Combined, our data suggest that Wnt/β-catenin signaling has a dual function in cochlear development, regulating both proliferation and hair cell differentiation.

A dual function for canonical Wnt/β-catenin signaling in the developing mammalian cochlea.

Planar cell polarity (PCP) regulates cell alignment required for collective cell movement during embryonic development. This requires PCP/PCP effector proteins, some of which also play essential roles in ciliogenesis, highlighting the long-standing question of the role of the cilium in PCP. Wdpcp, a PCP effector, was recently shown to regulate both ciliogenesis and collective cell movement, but the underlying mechanism is unknown. Here we show Wdpcp can regulate PCP by direct modulation of the actin cytoskeleton. These studies were made possible by recovery of a Wdpcp mutant mouse model. Wdpcp-deficient mice exhibit phenotypes reminiscent of Bardet-Biedl/Meckel-Gruber ciliopathy syndromes, including cardiac outflow tract and cochlea defects associated with PCP perturbation. We observed Wdpcp is localized to the transition zone, and in Wdpcp-deficient cells, Sept2, Nphp1, and Mks1 were lost from the transition zone, indicating Wdpcp is required for recruitment of proteins essential for ciliogenesis. Wdpcp is also found in the cytoplasm, where it is localized in the actin cytoskeleton and in focal adhesions. Wdpcp interacts with Sept2 and is colocalized with Sept2 in actin filaments, but in Wdpcp-deficient cells, Sept2 was lost from the actin cytoskeleton, suggesting Wdpcp is required for Sept2 recruitment to actin filaments. Significantly, organization of the actin filaments and focal contacts were markedly changed in Wdpcp-deficient cells. This was associated with decreased membrane ruffling, failure to establish cell polarity, and loss of directional cell migration. These results suggest the PCP defects in Wdpcp mutants are not caused by loss of cilia, but by direct disruption of the actin cytoskeleton. Consistent with this, Wdpcp mutant cochlea has normal kinocilia and yet exhibits PCP defects. Together, these findings provide the first evidence, to our knowledge, that a PCP component required for ciliogenesis can directly modulate the actin cytoskeleton to regulate cell polarity and directional cell migration.

Chandrakala Puligilla

Department of Pathology and Laboratory Medicine

Medical University of South Carolina, College of Medicine

Culture of Embryonic Mouse Cochlear Explants and Gene Transfer by Electroporation

Chandrakala Puligilla

.css-o250i3{font-size:18px;font-family:Open Sans,sans-serif;line-height:21.6px;}Department of Pathology and Laboratory Medicine

Medical University of South Carolina, College of Medicine

Culture of Embryonic Mouse Cochlear Explants and Gene Transfer by Electroporation

Department of Pathology and Laboratory Medicine