ex-vivo-culture-mouse-embryonic-skin-live-imaging-melanoblast

<em>Ex vivo</em> Culture of Mouse Embryonic Skin and Live-imaging of Melanoblast Migration

Melanoblasts are the neural crest derived precursors of melanocytes; the cells responsible for producing the pigment in skin and hair. Melanoblasts ...

University of Edinburgh

The mouse corneal epithelium is a continuously renewing 5-6 cell thick protective layer covering the corneal surface, which regenerates rapidly when injured. It is maintained by peripherally located limbal stem cells (LSCs) that produce transient amplifying cells (TACs) which proliferate, migrate centripetally, differentiate and are eventually shed from the epithelial surface. LSC activity is required both for normal tissue maintenance and wound healing. Mosaic analysis can provide insights into LSC function, cell movement and cell mixing during tissue maintenance and repair. The present study investigates cell streaming during corneal maintenance and repair and changes in LSC function with age.

Mosaic analysis of stem cell function and wound healing in the mouse corneal epithelium.

Quantitative analysis of mosaic tissues is a powerful method for following developmental lineages; however, analytical techniques are often subjective and repetitious. Here a flexible, semi-automated image analysis method for mosaic patterns is described. ClonalTools is a free customizable tool-set designed for the open-source image analysis package ImageJ. Circular, polygonal or linear one-dimensional mosaic arrays can be interrogated to provide measurements of the total number and width of positive and negative patches in a region of interest. These results are adjusted for the effects of random clumping using a previously described method to correct for differences in the contribution of the positive and negative cell type. The applicability of ClonalTools to different systems is discussed with reference to the analysis of mosaic patterns in the mouse corneal epithelium and adrenal cortex and in the outgrowth of neurites from explant cultures of mouse retina as example systems. To validate ClonalTools quantitatively, a recently published manual clonal analysis of the corneal epithelium of X-inactivation beta-Gal-mosaic mice was re-analysed. The semi-automated results did not differ significantly from the published data. Rapid quantification of such patterns to produce biologically relevant results represents a welcome improvement in terms of ease and speed of use over previous methods.

Quantitative analysis of patch patterns in mosaic tissues with ClonalTools software.

Ex vivo live imaging of melanoblast migration in embryonic mouse skin.

&#x5728;&#x80DA;&#x80CE;&#x53D1;&#x751F;&#xFF0C;melanoblasts &#x6269;&#x6563;&#x548C;&#x901A;&#x8FC7;&#x53D1;&#x5C55;&#x4E2D;&#x56FD;&#x5BB6;&#x7684;&#x771F;&#x76AE;&#x5C42;&#x548C;&#x8868;&#x76AE;&#x8179;&#x4FA7;&#x8FC1;&#x79FB;&#xFF0C;&#x4E3A;&#x5355;&#x4E2A;&#x5355;&#x5143;&#x683C;&#x3002;&#x80DA;&#x80CE;&#x53D1;&#x751F;&#x8FC7;&#x7A0B;&#x4E2D; melanoblasts Rac1 &#x7684;&#x76EE;&#x6807;&#x7684;&#x5220;&#x9664;&#x5BFC;&#x81F4;&#x8FC1;&#x79FB;&#x3001; &#x7EC6;&#x80DE;&#x5468;&#x671F;&#x8FDB;&#x7A0B;&#x548C;&#x80DE;&#x8D28;&#x5206;&#x88C2;&#x4E2D;&#x7684;&#x7F3A;&#x9677;&#x3002;Rac1 &#x7A7A;&#x7EC6;&#x80DE;&#x8FC1;&#x79FB;&#x663E;&#x8457;&#x8F83;&#x6709;&#x6548;&#xFF0C;&#x4F46;&#x5947;&#x602A;&#x7684;&#x662F;&#xFF0C;&#x5168;&#x7403;&#x8F6C;&#x5411;&#x3001; &#x7A7F;&#x8D8A;/&#x771F;&#x76AE;&#x8868;&#x76AE;&#x4EA4;&#x754C;&#x5904;&#xFF0C;&#x548C;&#x5F52;&#x5DE2;&#x6BDB;&#x56CA;&#x53D1;&#x751F;&#x4E00;&#x822C;&#x3002;Melanoblasts &#x5728;&#x4F7F;&#x7528;&#x4E24;&#x4E2A;&#x7C7B;&#x8170;&#x690E;&#x95F4;&#x76D8;&#x7A81;&#x51FA;&#x7684;&#x8868;&#x76AE;&#x4E2D;&#x5BFC;&#x822A;&#xFF1A; &#x77ED;&#x5B58;&#x6839; (stub) &#x53CA;&#x957F;&#x4F2A;&#x8DB3;&#x3002;&#x77ED;&#x7684;&#x5B58;&#x6839; (stub) &#x6709;&#x522B;&#x4E8E;&#x6CE1;&#x548C;&#x808C;&#x52A8;&#x86CB;&#x767D;&#x5927;&#x4F1A;&#x7531;&#x9A71;&#x52A8;&#x4F46;&#x72EC;&#x7ACB;&#x7684; Rac1&#x3001; Arp2/3 &#x590D;&#x6742;&#x3001; &#x808C;&#x7403;&#x86CB;&#x767D;&#x6216;&#x5FAE;&#x7BA1;&#x3002;Rac1 &#x79EF;&#x6781;&#x8C03;&#x8282;&#x542F;&#x52A8;&#x957F;&#x4F2A;&#x8DB3;&#xFF0C;&#x4FC3;&#x8FDB;&#x8FC1;&#x79FB;&#x901F;&#x5EA6;&#x548C;&#x5B9A;&#x5411;&#x53EF;&#x5851;&#x6027;&#x7684;&#x9891;&#x7387;&#x3002;&#x75A4;&#x75D5;/&#x6CE2;&#x548C; Arp2/3 &#x590D;&#x6742;&#x9A71;&#x52A8;&#x5668;&#x808C;&#x52A8;&#x86CB;&#x767D;&#x5927;&#x4F1A;&#x5EF6;&#x957F;&#x957F; pseudopod&#xFF0C;&#x8FD9;&#x4E5F;&#x53D6;&#x51B3;&#x4E8E;&#x5FAE;&#x7BA1;&#x52A8;&#x529B;&#x5B66;&#x3002;&#x808C;&#x7403;&#x86CB;&#x767D;&#x6536;&#x7F29;&#x5F71;&#x54CD;&#x9000;&#x7F29;&#xFF0C;&#x5E76;&#x5141;&#x8BB8;&#x901A;&#x8FC7;&#x590D;&#x6742;&#x7684; 3D &#x8868;&#x76AE;&#x73AF;&#x5883;&#x8FD0;&#x52A8;&#x7684;&#x90E8;&#x961F;&#x7EC4;&#x5EFA;&#x4F59;&#x989D;&#x957F;&#x4F2A;&#x8DB3;&#x7684;&#x6269;&#x5C55;&#x3002;

Rac1 &#x9A71;&#x52A8;&#x5668; melanoblast &#x7EC4;&#x7EC7;&#x5C0F;&#x9F20;&#x53D1;&#x80B2;&#x8FC7;&#x7A0B;&#x7684;&#x7B56;&#x5212; pseudopod-&#x9A71;&#x52A8;&#x52A8;&#x529B;&#x53CA;&#x7EC6;&#x80DE;&#x5468;&#x671F;&#x8FDB;&#x7A0B;&#x3002;

During embryogenesis, melanoblasts proliferate and migrate ventrally through the developing dermis andÂ epidermis as single cells. Targeted deletion of Rac1 in melanoblasts during embryogenesis causes defects in migration, cell-cycle progression, and cytokinesis. Rac1 null cells migrate markedly less efficiently, but surprisingly, global steering, crossing the dermal/epidermal junction, and homing to hair follicles occur normally. Melanoblasts navigate in the epidermis using two classes of protrusion: short stubs and long pseudopods. Short stubs are distinct from blebs and are driven by actin assembly but areÂ independent of Rac1, Arp2/3 complex, myosin, or microtubules. Rac1 positively regulates the frequency of initiation of long pseudopods, which promote migration speed and directional plasticity. Scar/WAVE and Arp2/3 complex drive actin assembly for long pseudopod extension, which also depends on microtubule dynamics. Myosin contractility balances the extension of long pseudopods by effecting retraction and allowing force generation for movement through the complex 3D epidermal environment.

Rac1 drives melanoblast organization during mouse development by orchestrating pseudopod- driven motility and cell-cycle progression.

Au cours de l&#39;embryogen&egrave;se, m&eacute;lanoblastes prolif&egrave;rent et migrent sur le ventre &agrave; travers le derme et l&#39;&eacute;piderme en d&eacute;veloppement comme des cellules individuelles. Suppression cibl&eacute;e de Rac1 en m&eacute;lanoblastes durant l&#39;embryogen&egrave;se provoque des d&eacute;fauts dans la migration, la progression du cycle cellulaire et la cytocin&egrave;se. RAC1 null cellules migrent nettement moins efficace, mais &eacute;tonnamment, directeur mondial, traversant la jonction dermo/&eacute;pidermique et autoguidage de follicules pileux se produisent normalement. M&eacute;lanoblastes naviguer dans l&#39;&eacute;piderme &agrave; l&#39;aide de deux classes de saillie : courts talons et longs pseudopodes. Talons courts sont distincts des bulles et sont conduits par l&#39;assemblage de l&#39;actine mais sont ind&eacute;pendantes de Rac1, complexe Arp2/3, la myosine ou microtubules. RAC1 r&eacute;gule positivement la fr&eacute;quence d&#39;ouverture de longs pseudopodes, qui encouragent la vitesse de migration et de plasticit&eacute; directionnelle. SCAR/WAVE et Arp2/3 complexe actine Laufwerk pour extension de longs pseudopodes, qui repose &eacute;galement sur la dynamique des microtubules. La contractilit&eacute; de la myosine &eacute;quilibre l&#39;extension des pseudopodes longs en effectuant la r&eacute;traction et autorisant la mise sur pied pour le mouvement &agrave; travers l&#39;environnement &eacute;pidermique 3D complexe.

RAC1 lecteurs organisation m&eacute;lanoblaste au cours du d&eacute;veloppement chez la souris par l&#39;orchestration des pseudopodes-ax&eacute; sur la motilit&eacute; et la progression du cycle cellulaire.

Durante l&#39;embriogenesi, melanoblasts proliferano e migrano ventralmente attraverso il derma e dell&#39;epidermide in via di sviluppo come le singole cellule. Eliminazione mirata di Rac1 in melanoblasts durante l&#39;embriogenesi causa difetti Citocinesi in migrazione e progressione del ciclo cellulare. Rac1 null cellule migrano nettamente meno efficiente, ma sorprendentemente, globale dello sterzo, attraversano la giunzione cutanea/epidermica e Radiobussola ai follicoli piliferi verificarsi normalmente. Melanoblasts spostarsi nell&#39;epidermide utilizzando due classi di protrusione: breve stub e lunghi pseudopodi. Categoria: breve sono distinti da squamosi e sono guidati dall&#39;Assemblea di actina ma indipendente di Rac1, Arp2/3 complessi, miosina e microtubuli. Rac1 regola positivamente la frequenza di apertura di lunghi pseudopodi, che promuovono la velocit&agrave; di migrazione e plasticit&agrave; direzionale. Scar/onda e Arp2/3 complessi actina complessivo di azionamento per estensione lungo pseudopodo, che dipende anche dalla dinamica dei microtubuli. Contrattile miosina equilibra l&#39;estensione dei lunghi pseudopodi effettuando retrazione e consentendo la generazione di forza per il movimento attraverso il complesso ambiente 3D epidermico.

Rac1 unit&agrave; organizzazione melanoblast durante lo sviluppo del mouse da orchestrare pseudopodo-driven motilit&agrave; e la progressione del ciclo cellulare.

&#x80DA;&#x3067;&#x306F;&#x3001;melanoblasts &#x306F;&#x5897;&#x6B96;&#x3057;&#x3001;&#x8179;&#x5074;&#x958B;&#x767A;&#x306E;&#x771F;&#x76AE;&#x3068;&#x8868;&#x76AE;&#x3092; 1 &#x3064;&#x306E;&#x30BB;&#x30EB;&#x3068;&#x3057;&#x3066;&#x79FB;&#x884C;&#x3057;&#x307E;&#x3059;&#x3002;&#x6B20;&#x9665;&#x79FB;&#x884C;&#x3001;&#x7D30;&#x80DE;&#x5468;&#x671F;&#x306E;&#x9032;&#x884C;&#x3001;&#x7D30;&#x80DE;&#x8CEA;&#x5206;&#x88C2;&#x304C; Rac1 melanoblasts &#x306E;&#x80DA;&#x767A;&#x751F;&#x306B;&#x4F34;&#x3046;&#x5BFE;&#x8C61;&#x524A;&#x9664;&#x3055;&#x308C;&#x307E;&#x3059;&#x3002;Rac1 null &#x7D30;&#x80DE;&#x79FB;&#x884C;&#x8457;&#x3057;&#x304F;&#x3088;&#x308A;&#x52B9;&#x7387;&#x7684;&#x306B;&#x3001;&#x3057;&#x304B;&#x3057;&#x9A5A;&#x3044;&#x305F;&#x3053;&#x3068;&#x306B;&#x3001;&#x4E16;&#x754C;&#x7684;&#x306A;&#x30B9;&#x30C6;&#x30A2;&#x30EA;&#x30F3;&#x30B0;&#x3001;&#x771F;&#x76AE;&#x8868;&#x76AE;&#x63A5;&#x5408;&#x90E8;&#x3092;&#x6A2A;&#x65AD;&#x3001;&#x6BDB;&#x5305;&#x3078;&#x306E;&#x30DB;&#x30FC;&#x30DF;&#x30F3;&#x30B0;&#x901A;&#x5E38;&#x767A;&#x751F;&#x3057;&#x307E;&#x3059;&#x3002;Melanoblasts &#x79FB;&#x52D5;&#x7A81;&#x8D77;&#x306E; 2 &#x3064;&#x306E;&#x30AF;&#x30E9;&#x30B9;&#x3092;&#x4F7F;&#x7528;&#x3057;&#x3066;&#x8868;&#x76AE;&#x306B;: &#x30B7;&#x30E7;&#x30FC;&#x30C8; &#x30B9;&#x30BF;&#x30D6;&#x3068;&#x9577;&#x3044;&#x4EEE;&#x8DB3;&#x3002;&#x30B7;&#x30E7;&#x30FC;&#x30C8; &#x30B9;&#x30BF;&#x30D6;&#x6C34;&#x75B1;&#x304B;&#x3089;&#x7570;&#x306A;&#x308B;&#x30A2;&#x30AF;&#x30C1;&#x30F3; &#x30A2;&#x30BB;&#x30F3;&#x30D6;&#x30EA;&#x306B;&#x3088;&#x3063;&#x3066;&#x99C6;&#x52D5;&#x3055;&#x308C;&#x308B;&#x304C;&#x3001;Rac1&#x3001;Arp2/3 &#x8907;&#x96D1;&#x306A;&#x30DF;&#x30AA;&#x30B7;&#x30F3;&#x3001;&#x307E;&#x305F;&#x306F;&#x5FAE;&#x5C0F;&#x7BA1;&#x306E;&#x72EC;&#x7ACB;&#x3057;&#x3066;&#x3044;&#x307E;&#x3059;&#x3002;Rac1 &#x306F;&#x7A4D;&#x6975;&#x7684;&#x306B;&#x79FB;&#x52D5;&#x901F;&#x5EA6;&#x3068;&#x65B9;&#x5411;&#x5851;&#x6027;&#x3092;&#x4FC3;&#x9032;&#x3059;&#x308B;&#x9577;&#x3044;&#x4EEE;&#x306E;&#x958B;&#x59CB;&#x983B;&#x5EA6;&#x3092;&#x8ABF;&#x6574;&#x3057;&#x307E;&#x3059;&#x3002;&#x50B7;&#x8DE1;/&#x6CE2;&#x3068; Arp2/3 &#x8907;&#x96D1;&#x306A;&#x30C9;&#x30E9;&#x30A4;&#x30D6;&#x306E;&#x30A2;&#x30AF;&#x30C1;&#x30F3;&#x96C6;&#x5408;&#x5FAE;&#x5C0F;&#x7BA1;&#x30C0;&#x30A4;&#x30CA;&#x30DF;&#x30AF;&#x30B9;&#x306F;&#x307E;&#x305F;&#x4F9D;&#x5B58;&#x9577;&#x3044;&#x4EEE;&#x8DB3;&#x306E;&#x62E1;&#x5F35;&#x5B50;&#x3002;&#x30DF;&#x30AA;&#x30B7;&#x30F3;&#x53CE;&#x7E2E;&#x62E1;&#x5F35;&#x306E;&#x9577;&#x3044;&#x4EEE;&#x8DB3;&#x306E;&#x64A4;&#x56DE;&#x306B;&#x5F71;&#x97FF;&#x3092;&#x4E0E;&#x3048;&#x3001;&#x8907;&#x96D1;&#x306A; 3 D &#x8868;&#x76AE;&#x74B0;&#x5883;&#x904B;&#x52D5;&#x306E;&#x529B;&#x767A;&#x751F;&#x3053;&#x3068;&#x304C;&#x3067;&#x304D;&#x307E;&#x3059;&#x30D0;&#x30E9;&#x30F3;&#x30B9;&#x3092;&#x3068;&#x308A;&#x307E;&#x3059;&#x3002;

Rac1 &#x507D;&#x8DB3; - &#x904B;&#x52D5;&#x3068;&#x7D30;&#x80DE;&#x5468;&#x671F;&#x306E;&#x9032;&#x884C;&#x3092;&#x99C6;&#x52D5;&#x306E;&#x8ABF;&#x6574;&#x306B;&#x3088;&#x3063;&#x3066;&#x30DE;&#x30A6;&#x30B9;&#x958B;&#x767A;&#x4E2D;&#x306B;&#x7D44;&#x7E54;&#x306B; melanoblast &#x3092;&#x99C6;&#x52D5;&#x3057;&#x307E;&#x3059;&#x3002;

Embryogenesis, &#xD558;&#xB294; &#xB3D9;&#xC548; melanoblasts &#xACA9; &#xC99D; &#xD55C; &#xB2E8;&#xC77C; &#xC140;&#xC73C;&#xB85C; &#xAC1C;&#xBC1C; &#xC9C4; &#xD53C;&#xC640; &#xD45C; &#xD53C;&#xB97C; &#xD1B5;&#xD574; ventrally &#xB9C8;&#xC774;&#xADF8;&#xB808;&#xC774;&#xC158;&#xD569;&#xB2C8;&#xB2E4;. Embryogenesis &#xC911; melanoblasts&#xC5D0;&#xC11C; Rac1 &#xB300;&#xC0C1;&#xB41C; &#xC0AD;&#xC81C; &#xD558;&#xBA74; &#xB9C8;&#xC774;&#xADF8;&#xB808;&#xC774;&#xC158;, &#xC138;&#xD3EC; &#xC8FC;&#xAE30; &#xC9C4;&#xD589; &#xBC0F; cytokinesis&#xC758; &#xACB0;&#xD568;. Rac1 null &#xC140; &#xB9C8;&#xC774;&#xADF8;&#xB808;&#xC774;&#xC158;&#xD560; &#xD604;&#xC800; &#xD558; &#xAC8C; &#xAE00;&#xB85C;&#xBC8C; &#xC2A4;&#xD2F0;&#xC5B4;&#xB9C1;, &#xD53C;&#xBD80; &#xD45C; &#xD53C; &#xC811;&#xD569;&#xC744; &#xAC74;&#xB108;&#xC640; &#xBAA8; &#xB0AD;&#xC5D0; &#xC790;&#xB3D9; &#xC704;&#xCE58; &#xBC1C;&#xC0DD; &#xC77C;&#xBC18;&#xC801;&#xC73C;&#xB85C; &#xB35C; &#xD6A8;&#xC728;&#xC801;&#xC73C;&#xB85C;, &#xD558;&#xC9C0;&#xB9CC; &#xB180;&#xB78D;&#xAC8C;&#xB3C4;. &#xB3CC;&#xCD9C;&#xC758; &#xB450; &#xD074;&#xB798;&#xC2A4;&#xB97C; &#xC0AC;&#xC6A9; &#xD558; &#xC5EC; &#xD45C; &#xD53C;&#xC5D0; melanoblasts &#xC774;&#xB3D9;: &#xC9E7;&#xC740; &#xBA85;&#xC138;&#xC11C;&#xC640; &#xAE34; pseudopods. &#xC9E7;&#xC740; &#xC2A4;&#xD141; blebs &#xAD6C;&#xBD84; &#xB418; &#xACE0; &#xB9D0;&#xB77C; &#xC5B4;&#xC148;&#xBE14;&#xB9AC;&#xC5D0; &#xC758;&#xD574; &#xAD6C;&#xB3D9; &#xB429;&#xB2C8;&#xB2E4; &#xD558;&#xC9C0;&#xB9CC; Rac1, Arp2/3 &#xBCF5;&#xC7A1; &#xD55C;, myosin, &#xB610;&#xB294; microtubules &#xB3C5;&#xB9BD;&#xC801;. Rac1 &#xAE0D;&#xC815;&#xC801;&#xC73C;&#xB85C; &#xB9C8;&#xC774;&#xADF8;&#xB808;&#xC774;&#xC158; &#xC18D;&#xB3C4; &#xBC0F; &#xBC29;&#xD5A5; &#xC18C;&#xC131; &#xAE34; pseudopods&#xC758; &#xAC1C;&#xC2DC;&#xC758; &#xC8FC;&#xD30C;&#xC218;&#xB97C; &#xC870;&#xC815; &#xD569;&#xB2C8;&#xB2E4;. &#xB610;&#xD55C; microtubule &#xC5ED;&#xD559;&#xC5D0; &#xB530;&#xB77C; &#xAE34; pseudopod &#xD655;&#xC7A5;&#xC5D0; &#xB300; &#xD55C; &#xD749;&#xD130;/&#xC6E8;&#xC774;&#xBE0C; &#xBC0F; Arp2/3 &#xBCF5;&#xC7A1; &#xD55C; &#xB4DC;&#xB77C;&#xC774;&#xBE0C; &#xB9D0;&#xB77C; &#xC5B4;&#xC148;&#xBE14;&#xB9AC;. Myosin &#xC218;&#xCD95; &#xCCA0;&#xD68C;&#xB97C; &#xCD08;&#xB798; &#xD558; &#xACE0; &#xBCF5;&#xC7A1; &#xD55C; 3D &#xD45C; &#xD53C; &#xD658;&#xACBD;&#xC744; &#xD1B5;&#xD574; &#xC6B4;&#xB3D9;&#xC5D0; &#xB300; &#xD55C; &#xAC15;&#xC81C; &#xC0DD;&#xC131; &#xD558; &#xC5EC; &#xAE34; pseudopods &#xD655;&#xC7A5;&#xC744; &#xADE0;&#xD615;.

Rac1 &#xAFB8;&#xBBF8;&#xACE0; pseudopod-&#xC6B4;&#xB3D9; &#xC131; &#xBC0F; &#xC138;&#xD3EC; &#xC8FC;&#xAE30; &#xC9C4;&#xD589;&#xC744; &#xAD6C;&#xB3D9; &#xD558; &#xC5EC; &#xB9C8;&#xC6B0;&#xC2A4; &#xAC1C;&#xBC1C; &#xD558;&#xB294; &#xB3D9;&#xC548; &#xC870;&#xC9C1; melanoblast &#xB4DC;&#xB77C;&#xC774;&#xBE0C;.

Durante la embriog&eacute;nesis, melanoblastos proliferan y migran ventralmente a trav&eacute;s de la dermis y epidermis en desarrollo como las c&eacute;lulas. Eliminaci&oacute;n dirigida de Rac1 en melanoblastos durante la embriog&eacute;nesis causa defectos en la migraci&oacute;n, la progresi&oacute;n del ciclo celular y la citocinesis. RAC1 nulas c&eacute;lulas migran notablemente menos eficientemente, pero sorprendentemente, manejo global, cruzando la uni&oacute;n dermo/epid&eacute;rmica y autoguiado hacia el blanco a los fol&iacute;culos pilosos se producen normalmente. Melanoblastos navegan en la epidermis mediante dos clases de la protuberancia: talones y largos seud&oacute;podos. Talones cortos son distintas de las ampollas y son conducidos por Asamblea de actina pero son independientes de Rac1, complejo Arp2/3, miosina o microt&uacute;bulos. RAC1 positivamente regula la frecuencia de apertura de largos seud&oacute;podos, favorecedoras de la velocidad de migraci&oacute;n y plasticidad direccional. Cicatriz/onda y Arp2/3 complejo actina conjunto impulsor para extensi&oacute;n larga seud&oacute;podo, que tambi&eacute;n depende de la din&aacute;mica de los microt&uacute;bulos. Contractilidad miosina equilibra la extensi&oacute;n de pseud&oacute;podos largos por efectuar retracci&oacute;n y permitiendo la generaci&oacute;n de fuerza para el movimiento a trav&eacute;s del complejo ambiente epid&eacute;rmico 3D.

RAC1 impulsa la organizaci&oacute;n de melanoblast durante el desarrollo del rat&oacute;n orquestando seud&oacute;podo-impulsada por la movilidad y la progresi&oacute;n del ciclo celular.

&#x8F6C;&#x79FB;&#x662F;&#x6B7B;&#x4E8E;&#x9ED1;&#x8272;&#x7D20;&#x7624;&#x3001; &#x76AE;&#x80A4;&#x764C;&#x5728;&#x897F;&#x65B9;&#x4E16;&#x754C;&#x4E2D;&#x5305;&#x542B;&#x7684;&#x4EFB;&#x4F55;&#x6076;&#x6027;&#x80BF;&#x7624;&#x53D1;&#x75C5;&#x7387;&#x4E0A;&#x5347;&#x6700;&#x5FEB;&#x7684;&#x4E3B;&#x8981;&#x539F;&#x56E0;&#x3002;&#x9A71;&#x52A8;&#x5668; melanoblast &#x8FC1;&#x79FB;&#x5728;&#x53D1;&#x5C55;&#x4E2D;&#x7684;&#x5206;&#x5B50;&#x9014;&#x5F84;&#x88AB;&#x8BA4;&#x4E3A;&#x8FD0;&#x52A8;&#x548C;&#x6700;&#x7EC8;&#x9ED1;&#x8272;&#x7D20;&#x7624;&#x8F6C;&#x79FB;&#x7684;&#x57FA;&#x7840;&#x3002;&#x5728;&#x8FD9;&#x91CC;&#x6211;&#x4EEC;&#x8868;&#x660E;&#x7F3A;&#x4E4F; P-Rex1&#xFF0C;Rac &#x7279;&#x5B9A; Rho &#x86CB;&#x767D;&#x9E1F;&#x560C;&#x5464;&#x6838;&#x82F7;&#x9178;&#x4EA4;&#x6362;&#x56E0;&#x5B50;&#x7684;&#x5C0F;&#x9F20; melanoblast &#x8FC1;&#x79FB;&#x5728;&#x8BC1;&#x660E;&#x767D;&#x809A;&#x7684;&#x5F00;&#x53D1;&#x8FC7;&#x7A0B;&#x4E2D;&#x7684;&#x7F3A;&#x9677;&#x3002;&#x6B64;&#x5916;&#xFF0C;&#x8FD9;&#x4E9B; P-Rex1(-/-) &#x5C0F;&#x9F20;&#x6709;&#x6297;&#x836F;&#x6027;&#x8F6C;&#x79FB;&#x6E21;&#x5230;&#x9ED1;&#x8272;&#x7D20;&#x7624;&#x5C0F;&#x9F20;&#x6A21;&#x578B;&#x3002;&#x673A;&#x68B0;&#x5316;&#xFF0C;&#x8FD9;&#x662F;&#x4E0E; P Rex1 &#x9A7E;&#x9A76;&#x5165;&#x4FB5; Rac &#x4F9D;&#x8D56;&#x7684;&#x65B9;&#x5F0F;&#x76F8;&#x5173;&#x8054;&#x3002;P Rex1 &#x88AB;&#x63D0;&#x5347;&#x4E2D;&#x7684;&#x5927;&#x591A;&#x6570;&#x4EBA;&#x9ED1;&#x8272;&#x7D20;&#x7624;&#x7EC6;&#x80DE;&#x682A;&#x548C;&#x80BF;&#x7624;&#x7EC4;&#x7EC7;&#x3002;&#x6211;&#x4EEC;&#x5F97;&#x51FA;&#x7684;&#x7ED3;&#x8BBA; P Rex1 melanoblast &#x8FC1;&#x79FB;&#x548C;&#x764C;&#x75C7;&#x8FDB;&#x5C55;&#x5728;&#x8001;&#x9F20;&#x548C;&#x4EBA;&#x7C7B;&#x8EAB;&#x4E0A;&#x8F6C;&#x79FB;&#x5230;&#x4E86;&#x91CD;&#x8981;&#x7684;&#x4F5C;&#x7528;&#x3002;

P Rex1 &#x662F;&#x5FC5;&#x9700;&#x7684;&#x9AD8;&#x6548; melanoblast &#x8FC1;&#x79FB;&#x548C;&#x9ED1;&#x8272;&#x7D20;&#x7624;&#x8F6C;&#x79FB;&#x3002;

Metastases are the major cause of death from melanoma, a skin cancer that has the fastest rising incidence of any malignancy in the Western world. Molecular pathways that drive melanoblast migration in development are believed to underpin the movement and ultimately the metastasis of melanoma. Here we show that mice lacking P-Rex1, a Rac-specific Rho GTPase guanine nucleotide exchange factor, have a melanoblast migration defect during development evidenced by a white belly. Moreover, these P-Rex1(-/-) mice are resistant to metastasis when crossed to a murine model of melanoma. Mechanistically, this is associated with P-Rex1 driving invasion in a Rac-dependent manner. P-Rex1 is elevated in the majority of human melanoma cell lines and tumour tissue. We conclude that P-Rex1 has an important role in melanoblast migration and cancer progression to metastasis in mice and humans.

P-Rex1 is required for efficient melanoblast migration and melanoma metastasis.

Les m&eacute;tastases sont la principale cause de d&eacute;c&egrave;s par m&eacute;lanome, un cancer de la peau qui a la plus forte augmentation de l&#39;incidence de toute tumeur maligne dans le monde occidental. Les voies mol&eacute;culaires qui animent la migration m&eacute;lanoblaste en d&eacute;veloppement sont cens&eacute;s soutenir le mouvement et finalement la m&eacute;tastase de m&eacute;lanome. Ici, nous montrons que les souris d&eacute;pourvues de P-Rex1, un facteur d&#39;&eacute;change nucl&eacute;otide guanine Rac sp&eacute;cifiques Rho GTPase, ont une migration m&eacute;lanoblaste d&eacute;fectuosit&eacute; durant le d&eacute;veloppement t&eacute;moigne d&#39;un ventre blanc. De plus, ces souris P-Rex1(-/-) r&eacute;sistent &agrave; m&eacute;tastases lorsque la travers&eacute;e d&#39;un mod&egrave;le murin de m&eacute;lanome. M&eacute;caniquement, cela est associ&eacute; &agrave; P-Rex1 invasion conduite en fonction de la Rac. P-Rex1 est &eacute;lev&eacute;e dans la majorit&eacute; des lign&eacute;es de cellules de m&eacute;lanome humain et de tissu tumoral. Nous concluons que le P-Rex1 a un r&ocirc;le important dans la progression du cancer et de la migration m&eacute;lanoblaste &agrave; m&eacute;tastases chez la souris et les humains.

P-Rex1 est requis pour la m&eacute;tastase de m&eacute;lanome et de migration m&eacute;lanoblaste efficace.

Knochenmetastasen sind die h&auml;ufigste Ursache f&uuml;r Tod von Melanom, ein Hautkrebs, der in der westlichen Welt die am schnellsten steigende Inzidenz einer Hyperkalz&auml;mie hat. Molekulare Bahnen, die fahren Melanocyt Migration in Entwicklung werden geglaubt, um die Bewegung und letztlich die Metastasierung von Melanom zu untermauern. Hier zeigen wir, dass M&auml;usen fehlt P-Rex1, ein Rac-spezifische Rho GTPase Guaninnukleotid-Austauschfaktor, eine Melanocyt Migration w&auml;hrend der Entwicklung durch einen wei&szlig;en Bauch belegt austragen. Dar&uuml;ber hinaus sind diese P-Rex1(-/-)-M&auml;use resistent gegen Metastasen in einem murinen Modell des Melanoms &uuml;berquerten. Mechanistisch, ist dies verbunden mit P-Rex1 treibende Invasion in Rac-abh&auml;ngigen Weise. P-Rex1 ist in den meisten menschlichen Melanom-Zelllinien und Tumorgewebe erh&ouml;ht. Wir schlie&szlig;en, dass P-Rex1 in Melanocyt Migration und Krebs Fortschreiten zu Metastasen bei M&auml;usen und Menschen eine wichtige Rolle spielt.

P-Rex1 ist erforderlich f&uuml;r effiziente Melanocyt Migration und Melanom-Metastase.

Metastasi sono la principale causa di morte da melanoma, un tumore della pelle che ha l&#39;incidenza crescente pi&ugrave; veloce di qualsiasi tumore maligno nel mondo occidentale. Pathways molecolari che guidano la migrazione melanoblast nello sviluppo sono creduto per sostenere il movimento e, in definitiva, le metastasi di melanoma. Qui vi mostriamo che topi privi di P-Rex1, un GTPasi Rho Rac-specifico fattore di scambio di nucleotide di guanina, hanno una migrazione melanoblast difetto durante lo sviluppo, evidenziato da un ventre bianco. Inoltre, questi topi P-Rex1(-/-) sono resistenti alle metastasi quando incrociate in un modello murino di melanoma. Meccanicistico, questo &egrave; associato con P-Rex1 guida invasione in modo Rac-dipendente. P-Rex1 &egrave; elevata nella maggior parte delle linee cellulari umane di melanoma e tumore del tessuto. Possiamo concludere che P-Rex1 ha un ruolo importante nella progressione di migrazione e cancro melanoblast a metastasi in topi ed esseri umani.

P-Rex1 &egrave; richiesto per metastasi migrazione e melanoma melanoblast efficiente.

&#x8EE2;&#x79FB;&#x60AA;&#x6027;&#x9ED2;&#x8272;&#x816B;&#x3001;&#x816B;&#x760D;&#x7D30;&#x80DE;&#x306E;&#x901F;&#x3044;&#x4E0A;&#x6607;&#x306E;&#x767A;&#x751F;&#x7387;&#x304C;&#x897F;&#x90E8;&#x306E;&#x4E16;&#x754C;&#x3067;&#x306F;&#x76AE;&#x819A;&#x764C;&#x306B;&#x3088;&#x308B;&#x6B7B;&#x4EA1;&#x306E;&#x4E3B;&#x8981;&#x306A;&#x539F;&#x56E0;&#x3067;&#x3059;&#x3002;Melanoblast &#x79FB;&#x884C;&#x99C6;&#x52D5;&#x958B;&#x767A;&#x306B;&#x304A;&#x3051;&#x308B;&#x5206;&#x5B50;&#x7D30;&#x9053;&#x52D5;&#x304D;&#x3068;&#x6700;&#x7D42;&#x7684;&#x306B;&#x60AA;&#x6027;&#x9ED2;&#x8272;&#x816B;&#x306E;&#x8EE2;&#x79FB;&#x3092;&#x4E0B;&#x652F;&#x3048;&#x3059;&#x308B;&#x3068;&#x8003;&#x3048;&#x3089;&#x308C;&#x3066;&#x3044;&#x307E;&#x3059;&#x3002;&#x3053;&#x3053;&#x3067;&#x6211;&#x3005; &#x306F; Rac &#x7279;&#x5B9A; Rho GTPase &#x30B0;&#x30A2;&#x30CB;&#x30F3;&#x30CC;&#x30AF;&#x30EC;&#x30AA;&#x30C1;&#x30C9;&#x4EA4;&#x63DB;&#x56E0;&#x5B50;, P Rex1 &#x306B;&#x6B20;&#x3051;&#x3066;&#x3044;&#x308B;&#x30DE;&#x30A6;&#x30B9;&#x306F;&#x767D;&#x3044;&#x8179;&#x306B;&#x3088;&#x3063;&#x3066;&#x8A3C;&#x660E;&#x3055;&#x308C;&#x308B;&#x958B;&#x767A;&#x4E2D;&#x306B;&#x6B20;&#x9665; melanoblast &#x79FB;&#x884C;&#x304C;&#x8868;&#x793A;&#x3055;&#x308C;&#x307E;&#x3059;&#x3002;&#x307E;&#x305F;&#x3001;&#x3053;&#x308C;&#x3089;&#x306E; P-Rex1(-/-) &#x306E;&#x30DE;&#x30A6;&#x30B9;&#x9ED2;&#x8272;&#x306E;&#x30DE;&#x30A6;&#x30B9;&#x30E2;&#x30C7;&#x30EB;&#x3078;&#x6E21;&#x3063;&#x305F;&#x3068;&#x304D;&#x8EE2;&#x79FB;&#x306B;&#x8010;&#x6027;&#x304C;&#x3042;&#x308A;&#x307E;&#x3059;&#x3002;&#x6A5F;&#x68B0;&#x8AD6;&#x7684;&#x306B;&#x3001;&#x3053;&#x308C;&#x306F; P Rex1 &#x904B;&#x8EE2;&#x4FB5;&#x7565; Rac &#x4F9D;&#x5B58;&#x7684;&#x306B;&#x95A2;&#x9023;&#x4ED8;&#x3051;&#x3089;&#x308C;&#x307E;&#x3059;&#x3002;P Rex1 &#x306F;&#x3072;&#x3068;&#x60AA;&#x6027;&#x9ED2;&#x8272;&#x816B;&#x7D30;&#x80DE;&#x682A;&#x3068;&#x816B;&#x760D;&#x7D44;&#x7E54;&#x306E;&#x5927;&#x90E8;&#x5206;&#x306E;&#x9AD8;&#x67B6;&#x3067;&#x3059;&#x3002;P Rex1 melanoblast &#x79FB;&#x884C;&#x3068;&#x764C;&#x306E;&#x9032;&#x884C;&#x306E;&#x30DE;&#x30A6;&#x30B9;&#x3068;&#x30D2;&#x30C8;&#x306B;&#x304A;&#x3051;&#x308B;&#x8EE2;&#x79FB;&#x3078;&#x306E;&#x91CD;&#x8981;&#x306A;&#x5F79;&#x5272;&#x3092;&#x6301;&#x3063;&#x3066;&#x3044;&#x308B;&#x3053;&#x3068;&#x3092;&#x7DE0;&#x7D50;&#x3057;&#x307E;&#x3059;&#x3002;

P Rex1 &#x306E;&#x305F;&#x3081;&#x306E;&#x52B9;&#x7387;&#x7684;&#x306A; melanoblast &#x79FB;&#x884C;&#x3068;&#x9ED2;&#x8272;&#x816B;&#x8EE2;&#x79FB;&#x304C;&#x5FC5;&#x8981;&#x3067;&#x3059;&#x3002;

&#xC804;&#xC774; &#xC11C;&#xBC29; &#xC138;&#xACC4;&#xC5D0;&#xC11C; &#xBAA8;&#xB4E0; &#xC545;&#xC131; &#xC885;&#xC591;&#xC758; &#xAC00;&#xC7A5; &#xBE60;&#xB978; &#xC0C1;&#xC2B9; &#xBC1C;&#xC0DD;&#xB960;&#xC740; &#xD53C;&#xBD80; &#xC554; &#xD751;&#xC0C9; &#xC885;&#xC5D0;&#xC11C; &#xC8FD;&#xC74C;&#xC758; &#xC8FC;&#xC694; &#xC6D0;&#xC778;&#xC785;&#xB2C8;&#xB2E4;. Melanoblast &#xB9C8;&#xC774;&#xADF8;&#xB808;&#xC774;&#xC158; &#xAC1C;&#xBC1C;&#xC5D0; &#xB4DC;&#xB77C;&#xC774;&#xBE0C; &#xD558;&#xB294; &#xBD84;&#xC790; &#xACBD;&#xB85C; &#xC6C0;&#xC9C1;&#xC784;&#xACFC; &#xAD81;&#xADF9;&#xC801;&#xC73C;&#xB85C; &#xD751;&#xC0C9; &#xC885; &#xC804;&#xC774; &#xADFC;&#xAC04;&#xC73C;&#xB85C; &#xCD94;&#xC815; &#xB41C;&#xB2E4;. &#xC5EC;&#xAE30; &#xC6B0;&#xB9AC;&#xAC00; P-Rex1, Rac &#xD2B9;&#xC815; Rho GTPase guanine &#xC5FC;&#xAE30; &#xAD50;&#xD658; &#xC694;&#xC18C; &#xBD80;&#xC871; &#xD55C; &#xC950;&#xAC00; &#xD558;&#xC580; &#xBC30;&#xB97C; &#xC785;&#xC99D; &#xD558;&#xB294; &#xAC1C;&#xBC1C; &#xD558;&#xB294; &#xB3D9;&#xC548; &#xACB0;&#xD568; melanoblast &#xB9C8;&#xC774;&#xADF8;&#xB808;&#xC774;&#xC158; &#xBCF4;&#xC5EC;&#xC90D;&#xB2C8;&#xB2E4;. &#xB610;&#xD55C;, &#xC774;&#xB7EC;&#xD55C; P-Rex1(-/-) &#xB9C8;&#xC6B0;&#xC2A4; &#xC804;&#xC774; &#xD751;&#xC0C9; &#xC885; murine &#xBAA8;&#xB378;&#xC744; &#xB118;&#xC5B4;&#xC5D0; &#xC800;&#xD56D;&#xB825;&#xC774; &#xC788;&#xB2E4;. Mechanistically,&#xC774; P-Rex1 &#xC6B4;&#xC804; &#xCE68;&#xACF5; Rac&#xC5D0; &#xC885;&#xC18D;&#xC801;&#xC778; &#xBC29;&#xC2DD;&#xC73C;&#xB85C; &#xC5F0;&#xACB0; &#xB429;&#xB2C8;&#xB2E4;. P-rex1&#xB294; &#xC778;&#xAC04;&#xC758; &#xD751;&#xC0C9; &#xC885; &#xC138;&#xD3EC; &#xC120;&#xC640; &#xC885;&#xC591; &#xC870;&#xC9C1;&#xC758; &#xB300;&#xBD80;&#xBD84;&#xC5D0;&#xC11C; &#xC0C1;&#xC2B9; &#xB41C;. &#xC6B0;&#xB9AC;&#xB294; P Rex1 &#xC0DD;&#xC950;&#xC640; &#xC778;&#xAC04; &#xC804;&#xC774;&#xB97C; melanoblast &#xB9C8;&#xC774;&#xADF8;&#xB808;&#xC774;&#xC158; &#xBC0F; &#xC554; &#xC9C4;&#xD589;&#xC5D0; &#xC911;&#xC694; &#xD55C; &#xC5ED;&#xD560;&#xC744;&#xAC00;&#xC9C0;&#xACE0; &#xACB0;&#xB860; &#xC9C0;&#xC5C8;&#xB2E4;.

P-rex1&#xB294; &#xD6A8;&#xC728;&#xC801;&#xC778; melanoblast &#xB9C8;&#xC774;&#xADF8;&#xB808;&#xC774;&#xC158; &#xBC0F; &#xD751;&#xC0C9; &#xC885; &#xC804;&#xC774; &#xD544;&#xC694; &#xD569;&#xB2C8;&#xB2E4;.

Las met&aacute;stasis son la principal causa de muerte de melanoma, un c&aacute;ncer de piel que tiene la mayor creciente incidencia de cualquier malignidad en el mundo occidental. V&iacute;as moleculares que impulsan la migraci&oacute;n melanoblast en desarrollo se creen que apuntalan el movimiento y, en &uacute;ltima instancia, la met&aacute;stasis del melanoma. Aqu&iacute; mostramos que los ratones que carecen de P-Rex1, un factor de cambio Rac espec&iacute;fica Rho GTPasa guanina nucle&oacute;tido, tienen una migraci&oacute;n de melanoblast defecto durante el desarrollo de un vientre blanco. Adem&aacute;s, estos ratones P-Rex1(-/-) son resistentes a met&aacute;stasis cuando cruz&oacute; a un modelo murino de melanoma. Mecan&iacute;sticamente, &eacute;sta se asocia con la invasi&oacute;n de conducci&oacute;n de P-Rex1 en una forma dependiente de Rac. P-Rex1 es elevada en la mayor&iacute;a de las l&iacute;neas celulares de melanoma humano y tejido tumoral. Concluimos que el P-Rex1 tiene un papel importante en la progresi&oacute;n de la migraci&oacute;n y el c&aacute;ncer de melanoblast a met&aacute;stasis en ratones y humanos.

P-Rex1 se requiere para la met&aacute;stasis de migraci&oacute;n y melanoma melanoblast eficiente.

Altered dosage of the transcription factor PAX6 causes multiple human eye pathophysiologies. PAX6⁺/⁻ heterozygotes suffer from aniridia and aniridia-related keratopathy (ARK), a corneal deterioration that probably involves a limbal epithelial stem cell (LESC) deficiency. Heterozygous Pax6(+/Sey-Neu) (Pax6⁺/⁻) mice recapitulate the human disease and are a good model of ARK. Corneal pathologies also occur in other mouse Pax6 mutants and in PAX77(Tg/-) transgenics, which over-express Pax6 and model human PAX6 duplication.

Effects of aberrant Pax6 gene dosage on mouse corneal pathophysiology and corneal epithelial homeostasis.

&#x8C03;&#x67E5;&#x7684;&#x7EC6;&#x80DE;&#x5185;&#x4FE1;&#x53F7;&#x8F6C;&#x5BFC;&#x4F5C;&#x7528;&#x8BF1;&#x53D1; Hedgehog (Hh) &#x914D;&#x4F53;&#x5728;&#x89D2;&#x819C;&#x7EF4;&#x4FEE;&#x548C;&#x4F24;&#x53E3;&#x6108;&#x5408;&#x3002;

&#x523A;&#x732C;&#x4FE1;&#x53F7;&#x548C; PAX6 &#x5242;&#x91CF;&#x4E4B;&#x95F4;&#x7684;&#x76F8;&#x4E92;&#x4F5C;&#x7528;&#x4ECB;&#x5BFC;&#x7EF4;&#x4FEE;&#x548C;&#x89D2;&#x819C;&#x4E0A;&#x76AE;&#x7EC6;&#x80DE;&#x7684;&#x518D;&#x751F;&#x3002;

To investigate the roles of intracellular signaling elicited by Hedgehog (Hh) ligands in corneal maintenance and wound healing.

Interaction between hedgehog signalling and PAX6 dosage mediates maintenance and regeneration of the corneal epithelium.

Pour enqu&#xEA;ter sur les r&#xF4;les de signalisation intracellulaires induites par Hedgehog (Hh) ligands dans l&#x26;#39;entretien de la corn&#xE9;e et la cicatrisation des plaies.

Interaction entre les Hedgehog signalisation et PAX6 Dosage m&#xE9;diateur maintien et la r&#xE9;g&#xE9;n&#xE9;ration de l&#x26;#39;&#xE9;pith&#xE9;lium corn&#xE9;en

Um zu untersuchen, die Rollen des intrazellul&auml;ren Signalisierens l&ouml;ste von Igel (Hh) Liganden bei Hornhaut Pflege und Heilung von Wunden.

Interaktion zwischen Igel Signalisierung und PAX6 Dosierung vermittelt die Wartung und Erneuerung der Hornhaut-Epithel.

Per indagare i ruoli di segnalazione intracellulare provocata dall&#39;Hedgehog (Hh) ligandi in manutenzione corneale e la guarigione della ferita.

Interazione tra riccio segnalazione e dosaggio di PAX6 media manutenzione e rigenerazione dell&#39;epitelio cornea.

&#x7D30;&#x80DE;&#x5185;&#x30B7;&#x30B0;&#x30CA;&#x30EB;&#x4F1D;&#x9054;&#x306E;&#x5F79;&#x5272;&#x3092;&#x691C;&#x8A0E;&#x3059;&#x308B;&#x305F;&#x3081;&#x306B;&#x89D2;&#x819C;&#x306E;&#x30E1;&#x30F3;&#x30C6;&#x30CA;&#x30F3;&#x30B9;&#x3068;&#x5275;&#x50B7;&#x6CBB;&#x7652;&#x306B;&#x304A;&#x3051;&#x308B;&#x30D8;&#x30C3;&#x30B8;&#x30DB;&#x30C3;&#x30B0;&#xFF08;Hh&#xFF09;&#x30EA;&#x30AC;&#x30F3;&#x30C9;&#x306B;&#x3088;&#x3063;&#x3066;&#x8A98;&#x767A;&#x3055;&#x308C;&#x308B;&#x3002;

&#x30D8;&#x30C3;&#x30B8;&#x30DB;&#x30C3;&#x30B0;&#x30B7;&#x30B0;&#x30CA;&#x30EB;&#x3068;&#x89D2;&#x819C;&#x4E0A;&#x76AE;&#x306E;PAX6&#x6295;&#x4E0E;&#x4EF2;&#x4ECB;&#x30E1;&#x30F3;&#x30C6;&#x30CA;&#x30F3;&#x30B9;&#x3068;&#x518D;&#x751F;&#x306E;&#x9593;&#x306E;&#x76F8;&#x4E92;&#x4F5C;&#x7528;

&#xC138;&#xD3EC;&#xB0B4; &#xC2DC;&#xADF8;&#xB110;&#xB9C1;&#xC758; &#xC5ED;&#xD560;&#xC744; &#xC870;&#xC0AC; &#xD558;&#xAE30; &#xC704;&#xD574; &#xAC01; &#xB9C9; &#xC720;&#xC9C0; &#xBCF4;&#xC218; &#xBC0F; &#xC0C1;&#xCC98; &#xCE58;&#xC720;&#xC5D0; ligands &#xACE0;&#xC2B4;&#xB3C4;&#xCE58; (Hh)&#xB85C; elicited.

&#xACE0;&#xC2B4;&#xB3C4;&#xCE58; &#xC2E0;&#xD638; &#xBC0F; PAX6 &#xBCF5;&#xC6A9;&#xB7C9; &#xC0AC;&#xC774; &#xC0C1;&#xD638; &#xC791;&#xC6A9;&#xC744; &#xC720;&#xC9C0; &#xBCF4;&#xC218; &#xBC0F; &#xAC01; &#xB9C9; &#xC0C1;&#xD53C;&#xC758; &#xC7AC;&#xC0DD; &#xC911;&#xC7AC;.

Para investigar el papel de la se&#xF1;alizaci&#xF3;n intracelular inducida por Hedgehog (Hh) ligandos en el mantenimiento de la c&#xF3;rnea y la cicatrizaci&#xF3;n de heridas.

Interacci&#xF3;n entre erizo de se&#xF1;alizaci&#xF3;n y Pax6 dosis de mantenimiento media y la regeneraci&#xF3;n del epitelio corneal

Some abnormalities of mouse corneal epithelial maintenance can be identified by the atypical mosaic patterns they produce in X-chromosome inactivation mosaics and chimeras. Human FLNA/+ females, heterozygous for X-linked, filamin A gene (FLNA) mutations, display a range of disorders and X-inactivation mosaicism is sometimes quantitatively unbalanced. FlnaDilp2/+ mice, heterozygous for an X-linked filamin A (Flna) nonsense mutation have variable eye, skeletal and other abnormalities, but X-inactivation mosaicism has not been investigated. The aim of this study was to determine whether X-inactivation mosaicism in the corneal epithelia of FlnaDilp2/+ mice was affected in any way that might predict abnormal corneal epithelial maintenance.

Normal X-inactivation mosaicism in corneas of heterozygous FlnaDilp2/+ female mice--a model of human filamin A (FLNA) diseases.

Around a fifth of melanomas exhibit an activating mutation in the oncogene NRas that confers constitutive signaling to proliferation and promotes tumor initiation. NRas signals downstream of the major melanocyte tyrosine kinase receptor c-kit and activated NRas results in increased signaling via the extracellular signal-regulated kinase (ERK)/MAPK/ERK kinase/mitogen-activated protein kinase (MAPK) pathways to enhance proliferation. The Ras oncogene also activates signaling via the related Rho GTPase Rac1, which can mediate growth, survival, and motility signaling. We tested the effects of activated NRas(Q61K) on the proliferation, motility, and invasiveness of melanoblasts and melanocytes in the developing mouse and ex vivo explant culture as well as in a melanoma transplant model. We find an important role for Rac1 downstream of NRas(Q61K) in mediating dermal melanocyte survival in vivo in mouse, but surprisingly NRas(Q61K) does not appear to affect melanoblast motility or proliferation during mouse embryogenesis. We also show that genetic deletion or pharmacological inhibition of Rac1 in NRas(Q61K) induced melanoma suppresses tumor growth, lymph node spread, and tumor cell invasiveness, suggesting a potential value for Rac1 as a therapeutic target for activated NRas-driven tumor growth and invasiveness.

Activated mutant NRas(Q61K) drives aberrant melanocyte signaling, survival, and invasiveness via a Rac1-dependent mechanism.

Maintenance of the corneal epithelium is essential for vision and is a dynamic process incorporating constant cell production, movement and loss. Although cell-based therapies involving the transplantation of putative stem cells are well advanced for the treatment of human corneal defects, the scientific understanding of these interventions is poor. No definitive marker that discriminates stem cells that maintain the corneal epithelium from the surrounding tissue has been discovered and the identity of these elusive cells is, therefore, hotly debated. The key elements of corneal epithelial maintenance have long been recognised but it is still not known how this dynamic balance is co-ordinated during normal homeostasis to ensure the corneal epithelium is maintained at a uniform thickness. Most indirect experimental evidence supports the limbal epithelial stem cell (LESC) hypothesis, which proposes that the adult corneal epithelium is maintained by stem cells located in the limbus at the corneal periphery. However, this has been challenged recently by the corneal epithelial stem cell (CESC) hypothesis, which proposes that during normal homeostasis the mouse corneal epithelium is maintained by stem cells located throughout the basal corneal epithelium with LESCs only contributing during wound healing. In this chapter we review experimental studies, mostly based on animal work, that provide insights into how stem cells maintain the normal corneal epithelium and consider the merits of the alternative LESC and CESC hypotheses. Finally, we highlight some recent research on other stem cell systems and consider how this could influence future research directions for identifying the stem cells that maintain the corneal epithelium.

Stem cells and corneal epithelial maintenance: insights from the mouse and other animal models.

A mouse mutant identified during a recessive N-ethyl-N-nitrosourea (ENU) mutagenesis screen exhibited ocular hemorrhaging resulting in a blood-filled orbit, and hence was named "redeye." We aimed to identify the causal mutation in redeye, and evaluate it as a model for diabetic retinopathy (DR).

A CNS-specific hypomorphic Pdgfr-beta mutant model of diabetic retinopathy.

We aimed to test previous predictions that limbal epithelial stem cells (LESCs) are quantitatively deficient or qualitatively defective in Pax6(+/-) mice and decline with age in wild-type (WT) mice. Consistent with previous studies, corneal epithelial stripe patterns coarsened with age in WT mosaics. Mosaic patterns were also coarser in Pax6(+/-) mosaics than WT at 15 weeks but not at 3 weeks, which excludes a developmental explanation and strengthens the prediction that Pax6(+/-) mice have a LESC-deficiency. To investigate how Pax6 genotype and age affected corneal homeostasis, we compared corneal epithelial cell turnover and label-retaining cells (LRCs; putative LESCs) in Pax6(+/-) and WT mice at 15 and 30 weeks. Limbal BrdU-LRC numbers were not reduced in the older WT mice, so this analysis failed to support the predicted age-related decline in slow-cycling LESC numbers in WT corneas. Similarly, limbal BrdU-LRC numbers were not reduced in Pax6(+/-) heterozygotes but BrdU-LRCs were also present in Pax6(+/-) corneas. It seems likely that Pax6(+/-) LRCs are not exclusively stem cells and some may be terminally differentiated CD31-positive blood vessel cells, which invade the Pax6(+/-) cornea. It was not, therefore, possible to use this approach to test the prediction that Pax6(+/-) corneas had fewer LESCs than WT. However, short-term BrdU labelling showed that basal to suprabasal movement (leading to cell loss) occurred more rapidly in Pax6(+/-) than WT mice. This implies that epithelial cell loss is higher in Pax6(+/-) mice. If increased corneal epithelial cell loss exceeds the cell production capacity it could cause corneal homeostasis to become unstable, resulting in progressive corneal deterioration. Although it remains unclear whether Pax6(+/-) mice have LESC-deficiency, we suggest that features of corneal deterioration, that are often taken as evidence of LESC-deficiency, might occur in the absence of stem cell deficiency if corneal homeostasis is destabilised by excessive cell loss.

Richard L. Mort

MRC Human Genetics Unit,
MRC IGMM,
Western General Hospital,
MRC Human Genetics Unit, MRC IGMM, Western General Hospital

University of Edinburgh

Ex vivo Culture of Mouse Embryonic Skin and Live-imaging of Melanoblast Migration

Richard L. Mort

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University of Edinburgh

Ex vivo Culture of Mouse Embryonic Skin and Live-imaging of Melanoblast Migration

MRC Human Genetics Unit,
MRC IGMM,
Western General Hospital,
MRC Human Genetics Unit, MRC IGMM, Western General Hospital