transposon-mediated-integration-plasmid-dna-into-subventricular-zone

Transposon Mediated Integration of Plasmid DNA into the Subventricular Zone of Neonatal Mice to Generate Novel Models of Glioblastoma

An urgent need exists to test the contribution of new genes to the pathogenesis and progression of human glioblastomas (GBM), the most common primary ...

University of Michigan School of Medicine

Diverse physiological actions of growth hormone (GH) are mediated by changes in gene transcription. Transcription can be regulated at several levels, including post-translational modification of transcription factors, and formation of multiprotein complexes involving transcription factors, co-regulators and additional nuclear proteins; these serve as targets for regulation by hormones and signaling pathways. Evidence that GH regulates transcription at multiple levels is exemplified by analysis of the proto-oncogene c-fos. Among the GH-regulated transcription factors on c-fos, C/EBPbeta appears to be key, since depletion of C/EBPbeta by RNA interference blocks the stimulation of c-fos by GH. The phosphorylation state of C/EBPbeta and its ability to activate transcription are regulated by GH through MAPK and PI3K/Akt-mediated signaling cascades. The acetylation of C/EBPbeta also contributes to its ability to activate c-fos transcription. These and other post-translational modifications of C/EBPbeta appear to be integrated for regulation of transcription by GH. The formation of nuclear proteins into complexes associated with DNA-bound transcription factors is also regulated by GH. Both C/EBPbeta and the co-activator p300 are recruited to c-fos in response to GH, altering c-fos promoter activation. In addition, GH rapidly induces spatio-temporal re-localization of C/EBPbeta within the nucleus. Thus, GH-regulated gene transcription mediated by C/EBPbeta reflects the integration of diverse mechanisms including post-translational modifications, modulation of protein complexes associated with DNA and re-localization of gene regulatory proteins. Similar integration involving other transcription factors, including Stats, appears to be a feature of regulation by GH of other gene targets.

Multiple mechanisms of growth hormone-regulated gene transcription.

&#x5728;&#x6210;&#x4EBA;&#x786C;&#x9AA8;&#x9C7C;&#x7C7B;&#x3001; &#x89C6;&#x7F51;&#x819C;&#x5E72;&#x7EC6;&#x80DE;&#x6301;&#x7EED;&#x5728;&#x4E24;&#x4E2A;&#x4E13;&#x95E8;&#x9886;&#x57DF;&#xFF1A; &#x776B;&#x72B6;&#x8FB9;&#x7F18;&#x533A; (CMZ) &#x548C;&#x5468;&#x56F4;&#x6210;&#x4EBA; M&uuml;ller &#x80F6;&#x8D28;&#x7EC6;&#x80DE;&#x7684;&#x5FAE;&#x73AF;&#x5883;&#x3002;&#x6700;&#x8FD1;&#xFF0C;M&uuml;ller &#x80F6;&#x8D28;&#x7EC6;&#x80DE;&#x88AB;&#x786E;&#x5B9A;&#x4E3A;&#x786C;&#x9AA8;&#x89C6;&#x7F51;&#x819C;&#x518D;&#x751F;&#x7684;&#x5E72;&#x7EC6;&#x80DE;&#x3002;&#x5F88;&#x5927;&#x7A0B;&#x5EA6;&#x4E0A;&#x672A;&#x77E5;&#x5206;&#x6CCC;&#x7684;&#x4FE1;&#x53F7;&#x5206;&#x5B50;&#x53EF;&#x4EE5;&#x901A;&#x8FC7;&#x8C03;&#x8282;&#x89C6;&#x7F51;&#x819C;&#x795E;&#x7ECF;&#x7EC6;&#x80DE;&#x518D;&#x751F;&#x3002;&#x5728;&#x82AF;&#x7247;&#x5C4F;&#x5E55;&#x4E2D;&#x53D1;&#x73B0;&#x8FD9;&#x79CD;&#x56E0;&#x7D20;&#xFF0C;&#x6211;&#x4EEC;&#x786E;&#x5B9A;&#x4E86;&#x4E2D;&#x671F;&#x56E0;&#x5B50;-b (mdkb)&#x3002;&#x4E2D;&#x671F;&#x56E0;&#x5B50;&#x662F;&#x9AD8;&#x5EA6;&#x4FDD;&#x5B88;&#x7684;&#x809D;&#x7D20;&#x7ED3;&#x5408;&#x751F;&#x957F;&#x56E0;&#x5B50;&#x4E0E;&#x4F17;&#x591A;&#x7684;&#x751F;&#x7269;&#x529F;&#x80FD;&#x3002;&#x6591;&#x9A6C;&#x9C7C;&#x57FA;&#x56E0;&#x7EC4;&#x5C06;&#x4E24;&#x4E2A;&#x4E0D;&#x540C;&#x7684;&#x4E2D;&#x671F;&#x56E0;&#x5B50;&#x57FA;&#x56E0;&#x7F16;&#x7801;&#xFF1A; mdka &#x548C; mdkb&#x3002;&#x6211;&#x4EEC;&#x5728;&#x8FD9;&#x91CC;&#x4ECB;&#x7ECD;&#x7684; mdka &#x548C; mdkb &#x89C6;&#x7F51;&#x819C;&#x53D1;&#x80B2;&#x8FC7;&#x7A0B;&#x7684;&#x7EC6;&#x80DE;&#x8868;&#x8FBE;&#x548C;&#x611F;&#x5149;&#x5668;&#x518D;&#x751F;&#x7684;&#x521D;&#x59CB;&#x3001; &#x589E;&#x6B96;&#x9636;&#x6BB5;&#x3002;&#x8C03;&#x67E5;&#x7ED3;&#x679C;&#x663E;&#x793A;&#x5728;&#x80DA;&#x80CE;&#x53CA;&#x5E7C;&#x4F53;&#x89C6;&#x7F51;&#x819C;&#x4E2D; mdka &#x548C; mdkb &#x90FD;&#x8868;&#x793A;&#x5728;&#x5E72;&#x7EC6;&#x80DE;&#x3001; &#x89C6;&#x7F51;&#x819C;&#x7956;&#x7EC6;&#x80DE;&#x548C;&#x795E;&#x7ECF;&#x5143;&#x4E2D;&#x5EFA;&#x8BAE;&#x7684;&#x4E24;&#x4E2A;&#x5206;&#x5B50;&#x7684;&#x4E0D;&#x540C;&#x804C;&#x80FD;&#x7684;&#x4E0D;&#x540C;&#x6A21;&#x5F0F;&#x3002;&#x5728;&#x6210;&#x4EBA;&#x3001; mdka &#x548C; mdkb &#x7684;&#x611F;&#x5149;&#x7EC6;&#x80DE;&#x9009;&#x62E9;&#x6027;&#x6B7B;&#x4EA1;&#x4E4B;&#x540E;&#x88AB; coexpressed &#x6C34;&#x5E73;&#x7EC6;&#x80DE;&#x548C;&#x589E;&#x6B96; M&uuml;ller &#x80F6;&#x8D28;&#x548C;&#x795E;&#x7ECF;&#x6E90;&#x6027;&#x540E;&#x4EE3;&#x3002;&#x8FD9;&#x4E9B;&#x6570;&#x636E;&#x8868;&#x660E;&#xFF0C;Mdka &#x548C; Mdkb &#x4FE1;&#x53F7;&#x56E0;&#x7D20;&#x76EE;&#x524D;&#x5728;&#x80DA;&#x80CE;&#x548C;&#x6210;&#x719F;&#x89C6;&#x7F51;&#x819C;&#x7684;&#x89C6;&#x7F51;&#x819C;&#x5E72;&#x7EC6;&#x80DE;&#x58C1;&#x9F9B;&#x548C;&#x5176;&#x7EC6;&#x80DE;&#x8868;&#x8FBE;&#x79EF;&#x6781;&#x8C03;&#x5236;&#x5728;&#x89C6;&#x7F51;&#x819C;&#x53D1;&#x80B2;&#x548C;&#x518D;&#x751F;&#x8FC7;&#x7A0B;&#x3002;

&#x4E2D;&#x671F;&#x56E0;&#x5B50; a &#x548C;&#x56E0;&#x5B50; b &#x7684;&#x6591;&#x9A6C;&#x9C7C;&#x89C6;&#x7F51;&#x819C;&#x611F;&#x5149;&#x5668;&#x548C;&#x53D1;&#x5C55;&#x518D;&#x751F;&#x8FC7;&#x7A0B;&#x4E2D;&#x7EC6;&#x80DE;&#x8868;&#x8FBE;&#x3002;

In the retina of adult teleosts, stem cells are sustained in two specialized niches: the ciliary marginal zone (CMZ) and the microenvironment surrounding adult MÃ¼ller glia. Recently, MÃ¼ller glia were identified as the regenerative stem cells in the teleost retina. Secreted signaling molecules that regulate neuronal regeneration in the retina are largely unknown. In a microarray screen to discover such factors, we identified midkine-b (mdkb). Midkine is a highly conserved heparin-binding growth factor with numerous biological functions. The zebrafish genome encodes two distinct midkine genes: mdka and mdkb. Here we describe the cellular expression of mdka and mdkb during retinal development and the initial, proliferative phase of photoreceptor regeneration. The results show that in the embryonic and larval retina mdka and mdkb are expressed in stem cells, retinal progenitors, and neurons in distinct patterns that suggest different functions for the two molecules. Following the selective death of photoreceptors in the adult, mdka and mdkb are coexpressed in horizontal cells and proliferating MÃ¼ller glia and their neurogenic progeny. These data reveal that Mdka and Mdkb are signaling factors present in the retinal stem cell niches in both embryonic and mature retinas, and that their cellular expression is actively modulated during retinal development and regeneration.

Cellular expression of midkine-a and midkine-b during retinal development and photoreceptor regeneration in zebrafish.

Dans la r&#xE9;tine des t&#xE9;l&#xE9;ost&#xE9;ens adultes, les cellules souches sont maintenues dans deux cr&#xE9;neaux sp&#xE9;cialis&#xE9;s: la zone ciliaire marginal (CMZ) et le microenvironnement autour cellules gliales de M&#xFC;ller adulte. R&#xE9;cemment, cellules gliales de M&#xFC;ller ont &#xE9;t&#xE9; identifi&#xE9;s comme les cellules souches r&#xE9;g&#xE9;n&#xE9;ratives dans la r&#xE9;tine des t&#xE9;l&#xE9;ost&#xE9;ens. S&#xE9;cr&#xE9;t&#xE9;es mol&#xE9;cules de signalisation qui r&#xE9;gulent la r&#xE9;g&#xE9;n&#xE9;ration neuronale dans la r&#xE9;tine sont en grande partie inconnue. Dans un &#xE9;cran de puces &#xE0; ADN pour d&#xE9;couvrir ces facteurs, nous avons identifi&#xE9; midkine-b (mdkb). Midkine est un facteur de croissance hautement conserv&#xE9;e liaison &#xE0; l&#x26;#39;h&#xE9;parine avec de nombreuses fonctions biologiques. Le g&#xE9;nome du poisson z&#xE8;bre code deux g&#xE8;nes distincts: Midkine mdka et mdkb. Nous d&#xE9;crivons ici l&#x26;#39;expression cellulaire de mdka et mdkb au cours du d&#xE9;veloppement de la r&#xE9;tine et l&#x26;#39;initiale, phase prolif&#xE9;rative de la r&#xE9;g&#xE9;n&#xE9;ration photor&#xE9;cepteur. Les r&#xE9;sultats montrent que dans la r&#xE9;tine embryonnaire et larvaire mdka et mdkb sont exprim&#xE9;s dans les cellules souches, les prog&#xE9;niteurs de la r&#xE9;tine, et les neurones dans des mod&#xE8;les distincts qui sugg&#xE8;rent des fonctions diff&#xE9;rentes pour les deux mol&#xE9;cules. Apr&#xE8;s la mort s&#xE9;lective des photor&#xE9;cepteurs chez l&#x26;#39;adulte, et mdka mdkb sont co-exprim&#xE9;s dans les cellules gliales M&#xFC;ller horizontales et la prolif&#xE9;ration et de leur prog&#xE9;niture neurog&#xE8;ne. Ces donn&#xE9;es r&#xE9;v&#xE8;lent que Mdka et Mdkb sont de signalisation des facteurs pr&#xE9;sents dans les niches de cellules souches r&#xE9;tiniennes dans la r&#xE9;tine &#xE0; la fois embryonnaires et mature, et que leur expression cellulaire est activement modul&#xE9;e au cours du d&#xE9;veloppement de la r&#xE9;tine et la r&#xE9;g&#xE9;n&#xE9;ration.

Expression cellulaire de Midkine-a et-b Midkine au cours du d&#xE9;veloppement de la r&#xE9;tine et la r&#xE9;g&#xE9;n&#xE9;ration photor&#xE9;cepteur chez le poisson z&#xE8;bre

In der Netzhaut des Erwachsenen Teleosts, sind Stammzellen in zwei spezielle Nischen nachhaltig: die Zilien Marginalzonen (CMZ) und der umgebenden Erwachsenen M&uuml;ller Glia Mikromilieu. Vor kurzem wurden M&uuml;ller Glia als die regenerative Stammzellen in teleost Netzhaut identifiziert. Sezernierte signalisierende Molek&uuml;le, die neuronalen Regeneration in der Netzhaut zu regulieren, sind weitgehend unbekannt. In einem Microarray-Bildschirm, solche Faktoren zu entdecken haben wir Midkine-b (Mdkb) identifiziert. Midkine ist ein stark konservierten Heparin-Bindung-Wachstumsfaktor mit zahlreichen biologischen Funktionen. Das Zebrafish Genom kodiert f&uuml;r zwei unterschiedliche midkine Gene: Mdka und Mdkb. Hier beschreiben wir zellul&auml;re Ausdruck der Mdka und Mdkb w&auml;hrend der retinalen Entwicklung und die anf&auml;ngliche proliferative Phase der Photorezeptoren Regeneration. Die Ergebnisse zeigen, dass in der embryonalen und larval Retina Mdka und Mdkb ausgedr&uuml;ckt werden, in Stammzellen, retinale Vorl&auml;uferzellen und Neuronen in verschiedenen Mustern, die verschiedene Funktionen f&uuml;r die zwei Molek&uuml;le nahe legen. Nach dem selektiven Tod von Photorezeptoren im Erwachsenen, Mdka und Mdkb sind coexpressed, horizontale Zellen und wuchernden M&uuml;ller Glia neurogenen nachkommen. Diese Daten zeigen, dass Mdka und Mdkb Signalisierung sind Faktoren in den retinalen Stammzell-Nischen in sowohl embryonalen und Reifen Netzhaut zu pr&auml;sentieren, und dass ihre zellul&auml;re Ausdruck aktiv w&auml;hrend retinalen Entwicklung und Regeneration moduliert wird.

Zellul&auml;re Ausdruck des Midkine-a und Midkine-b w&auml;hrend retinalen Entwicklung und Photorezeptoren Regeneration im Zebrafisch.

Nella retina di teleostei adulti, le cellule staminali sono sostenute in due nicchie specializzate: la zona marginale ciliare (CMZ) e il microambiente circostante adulti glia di M&uuml;ller. Recentemente, glia di M&uuml;ller sono stati identificati come le cellule staminali rigenerative nella retina teleostei. Secrete molecole di segnalazione che regolano la rigenerazione neuronale nella retina sono in gran parte sconosciuti. In una schermata di microarray per scoprire tali fattori, abbiamo identificato midkine-b (mdkb). Midkine &egrave; un fattore di crescita altamente conservato eparina-associazione con numerose funzioni biologiche. Il genoma di zebrafish codifica due geni distinti midkine: mdka e mdkb. Qui descriviamo l&#39;espressione cellulare di mdka e mdkb durante lo sviluppo della retina e la fase iniziale, proliferativa della rigenerazione del fotorecettore. I risultati mostrano che nella retina embrionale e larvale mdka e mdkb sono espressi in cellule staminali, progenitori della retina e neuroni in modelli distinti che suggeriscono di funzioni diverse per le due molecole. Dopo la morte selettiva dei fotorecettori nell&#39;adulto, mdka e mdkb sono coespressi nelle cellule orizzontali e proliferazione glia di M&uuml;ller e loro progenie neurogena. Questi dati rivelano che Mdka e Mdkb sono segnalazione fattori presentano nelle nicchie della retina cellule staminali nella retina embrionale e maturo, e che la loro espressione cellulare attivamente &egrave; modulato durante la rigenerazione e lo sviluppo della retina.

Cellulare espressione di midkine-a e midkine-b durante la rigenerazione di sviluppo e fotorecettori retinica in zebrafish.

&#x6BDB;&#x69D8;&#x4F53;&#x8FBA;&#x7E01;&#x5E2F;&#xFF08;CMZ&#xFF09;&#x3068;&#x5927;&#x4EBA;&#x306E;&#x30DF;&#x30E5;&#x30E9;&#x30FC;&#x30B0;&#x30EA;&#x30A2;&#x7D30;&#x80DE;&#x3092;&#x53D6;&#x308A;&#x5DFB;&#x304F;&#x5FAE;&#x5C0F;&#x74B0;&#x5883;&#xFF1A;&#x5927;&#x4EBA;&#x306E;&#x786C;&#x9AA8;&#x985E;&#x306E;&#x7DB2;&#x819C;&#x3067;&#x306F;&#x3001;&#x5E79;&#x7D30;&#x80DE;&#x306F;&#x4E8C;&#x3064;&#x306E;&#x5C02;&#x9580;&#x306E;&#x30CB;&#x30C3;&#x30C1;&#x306B;&#x7DAD;&#x6301;&#x3055;&#x308C;&#x3066;&#x3044;&#x307E;&#x3059;&#x3002;&#x6700;&#x8FD1;&#x3067;&#x306F;&#x3001;&#x30DF;&#x30E5;&#x30E9;&#x30FC;&#x30B0;&#x30EA;&#x30A2;&#x7D30;&#x80DE;&#x306F;&#x3001;&#x786C;&#x9AA8;&#x9B5A;&#x7DB2;&#x819C;&#x306E;&#x518D;&#x751F;&#x5E79;&#x7D30;&#x80DE;&#x3068;&#x3057;&#x3066;&#x540C;&#x5B9A;&#x3055;&#x308C;&#x305F;&#x3002;&#x7DB2;&#x819C;&#x3067;&#x306E;&#x795E;&#x7D4C;&#x518D;&#x751F;&#x3092;&#x8ABF;&#x7BC0;&#x3059;&#x308B;&#x5206;&#x6CCC;&#x30B7;&#x30B0;&#x30CA;&#x30EB;&#x5206;&#x5B50;&#x306E;&#x5927;&#x90E8;&#x5206;&#x306F;&#x672A;&#x77E5;&#x3067;&#x3042;&#x308B;&#x3002;&#x3053;&#x306E;&#x3088;&#x3046;&#x306A;&#x8981;&#x56E0;&#x3092;&#x767A;&#x898B;&#x3059;&#x308B;&#x305F;&#x3081;&#x306E;&#x30DE;&#x30A4;&#x30AF;&#x30ED;&#x30A2;&#x30EC;&#x30A4;&#x306E;&#x753B;&#x9762;&#x3067;&#x306F;&#x3001;&#x6211;&#x3005;&#x306F;&#x30DF;&#x30C3;&#x30C9;&#x30AB;&#x30A4;&#x30F3;-B&#xFF08;mdkb&#xFF09;&#x3092;&#x540C;&#x5B9A;&#x3057;&#x305F;&#x3002;&#x30DF;&#x30C3;&#x30C9;&#x30AB;&#x30A4;&#x30F3;&#x306F;&#x591A;&#x6570;&#x306E;&#x751F;&#x7269;&#x5B66;&#x7684;&#x6A5F;&#x80FD;&#x3092;&#x6301;&#x3064;&#x9AD8;&#x5EA6;&#x306B;&#x4FDD;&#x5B58;&#x3055;&#x308C;&#x305F;&#x30D8;&#x30D1;&#x30EA;&#x30F3;&#x7D50;&#x5408;&#x6027;&#x6210;&#x9577;&#x56E0;&#x5B50;&#x3067;&#x3042;&#x308B;&#x3002; mdka&#x3068;mdkb&#xFF1A;&#x30BC;&#x30D6;&#x30E9;&#x30D5;&#x30A3;&#x30C3;&#x30B7;&#x30E5;&#x306E;&#x30B2;&#x30CE;&#x30E0;&#x306F;&#x3001;2&#x3064;&#x306E;&#x7570;&#x306A;&#x308B;&#x30DF;&#x30C3;&#x30C9;&#x30AB;&#x30A4;&#x30F3;&#x907A;&#x4F1D;&#x5B50;&#x3092;&#x30B3;&#x30FC;&#x30C9;&#x3057;&#x3066;&#x3044;&#x308B;&#x3002;&#x3053;&#x3053;&#x3067;&#x306F;&#x3001;&#x7DB2;&#x819C;&#x306E;&#x958B;&#x767A;&#x3068;&#x611F;&#x5149;&#x4F53;&#x518D;&#x751F;&#x306E;&#x521D;&#x671F;&#x3001;&#x5897;&#x6B96;&#x671F;&#x306E;&#x9593;&#x306B;mdka&#x3068;mdkb&#x306E;&#x7D30;&#x80DE;&#x767A;&#x73FE;&#x3092;&#x8AAC;&#x660E;&#x3057;&#x307E;&#x3059;&#x3002;&#x7D50;&#x679C;&#x306F;&#x3001;&#x80DA;&#x304A;&#x3088;&#x3073;&#x5E7C;&#x866B;&#x306E;&#x7DB2;&#x819C;&#x306B;mdka&#x3068;mdkb&#x3001;&#x5E79;&#x7D30;&#x80DE;&#x3001;&#x7DB2;&#x819C;&#x524D;&#x99C6;&#x7D30;&#x80DE;&#x3001;&#x4E8C;&#x5206;&#x5B50;&#x306E;&#x3055;&#x307E;&#x3056;&#x307E;&#x306A;&#x6A5F;&#x80FD;&#x3092;&#x793A;&#x5506;&#x3057;&#x3066;&#x3044;&#x308B;&#x660E;&#x78BA;&#x306A;&#x30D1;&#x30BF;&#x30FC;&#x30F3;&#x306E;&#x30CB;&#x30E5;&#x30FC;&#x30ED;&#x30F3;&#x306B;&#x767A;&#x73FE;&#x3055;&#x308C;&#x308B;&#x3053;&#x3068;&#x3092;&#x793A;&#x3057;&#x3066;&#x3044;&#x308B;&#x3002;&#x6210;&#x4EBA;&#x306B;&#x304A;&#x3051;&#x308B;&#x5149;&#x53D7;&#x5BB9;&#x4F53;&#x306E;&#x9078;&#x629E;&#x7684;&#x306A;&#x6B7B;&#x306B;&#x7D9A;&#x3044;&#x3066;&#x3001;mdka&#x3068;mdkb&#x306F;&#x6C34;&#x5E73;&#x7D30;&#x80DE;&#x3068;&#x5897;&#x6B96;&#x30DF;&#x30E5;&#x30E9;&#x30FC;&#x30B0;&#x30EA;&#x30A2;&#x7D30;&#x80DE;&#x3068;&#x305D;&#x306E;&#x795E;&#x7D4C;&#x6027;&#x306E;&#x5B50;&#x5B6B;&#x3067;&#x5171;&#x767A;&#x73FE;&#x3055;&#x308C;&#x3066;&#x3044;&#x307E;&#x3059;&#x3002;&#x3053;&#x308C;&#x3089;&#x306E;&#x30C7;&#x30FC;&#x30BF;&#x306F;Mdka&#x3068;Mdkb&#x306F;&#x3001;&#x80DA;&#x3068;&#x6210;&#x719F;&#x3057;&#x305F;&#x4E21;&#x65B9;&#x306E;&#x7DB2;&#x819C;&#x306B;&#x304A;&#x3051;&#x308B;&#x7DB2;&#x819C;&#x5E79;&#x7D30;&#x80DE;&#x306E;&#x30CB;&#x30C3;&#x30C1;&#x306B;&#x5B58;&#x5728;&#x3059;&#x308B;&#x56E0;&#x5B50;&#x3092;&#x30B7;&#x30B0;&#x30CA;&#x30EB;&#x4F1D;&#x9054;&#x3057;&#x3066;&#x3044;&#x308B;&#x3053;&#x3068;&#x3092;&#x660E;&#x3089;&#x304B;&#x306B;&#x3057;&#x3001;&#x305D;&#x308C;&#x3089;&#x306E;&#x7D30;&#x80DE;&#x306E;&#x767A;&#x73FE;&#x306F;&#x3001;&#x7DB2;&#x819C;&#x306E;&#x958B;&#x767A;&#x3084;&#x518D;&#x751F;&#x4E2D;&#x306B;&#x7A4D;&#x6975;&#x7684;&#x306B;&#x5909;&#x8ABF;&#x3055;&#x308C;&#x3066;&#x3044;&#x308B;&#x3053;&#x3068;&#x3002;

&#x30BC;&#x30D6;&#x30E9;&#x30D5;&#x30A3;&#x30C3;&#x30B7;&#x30E5;&#x306E;&#x7DB2;&#x819C;&#x306E;&#x958B;&#x767A;&#x3068;&#x611F;&#x5149;&#x4F53;&#x306E;&#x518D;&#x751F;&#x6642;&#x306B;&#x30DF;&#x30C3;&#x30C9;&#x30AB;&#x30A4;&#x30F3;&#x3068;&#x30AB;&#x30A4;&#x30F3;-B&#x306E;&#x7D30;&#x80DE;&#x767A;&#x73FE;

&#xC131;&#xC778; teleosts &#xB9DD;&#xB9C9; &#xC904;&#xAE30; &#xC138;&#xD3EC; &#xB450; &#xC804;&#xBB38;&#xB41C; &#xD2C8;&#xC0C8;&#xC5D0;&#xC11C; &#xC9C0;&#xC18D; &#xB429;&#xB2C8;&#xB2E4;: &#xC18D;&#xB208;&#xC379; &#xD55C;&#xACC4; &#xC601;&#xC5ED; (CMZ)&#xC640; &#xC131;&#xC778; &#xBB90;&#xB7EC; &#xBA85;&#xACFC; &#xC8FC;&#xBCC0; microenvironment. &#xCD5C;&#xADFC;, &#xBB90;&#xB7EC; &#xBA85;&#xACFC; teleost &#xB9DD;&#xB9C9;&#xC5D0; &#xC7AC;&#xC0DD; &#xC904;&#xAE30; &#xC138;&#xD3EC;&#xB85C; &#xD655;&#xC778; &#xB410;&#xB2E4;. &#xB9DD;&#xB9C9; &#xC2E0;&#xACBD; &#xC7AC;&#xC0DD;&#xC744; &#xC870;&#xC808; &#xD558;&#xB294; &#xBE44; &#xC2E0;&#xD638; &#xBD84;&#xC790; &#xD06C;&#xAC8C; &#xC54C;&#xB824;&#xC9C0;&#xC9C0; &#xC54A;&#xC740;.&#xC785;&#xB2C8;&#xB2E4;. &#xC774;&#xB7EC;&#xD55C; &#xC694;&#xC778;&#xC744; microarray &#xD654;&#xBA74;&#xC5D0;&#xC11C; midkine-b (mdkb) &#xD30C;&#xC545;. Midkine&#xC740; &#xB2E4;&#xC591; &#xD55C; &#xC0DD;&#xBB3C; &#xD559;&#xC801; &#xAE30;&#xB2A5;&#xC744; &#xACE0;&#xB3C4;&#xB85C; &#xBCF4;&#xC874;&#xB41C; &#xD5E4; &#xD30C; &#xB9B0; &#xBC14;&#xC778;&#xB529; &#xC131;&#xC7A5; &#xC694;&#xC18C; &#xC774;&#xB2E4;. Zebrafish &#xAC8C;&#xB188; &#xC778;&#xCF54;&#xB529;&#xD569;&#xB2C8;&#xB2E4; midkine &#xC720;&#xC804;&#xC790; &#xB450; &#xAC00;&#xC9C0;: mdka &#xBC0F; mdkb. &#xC5EC;&#xAE30; &#xC6B0;&#xB9AC; mdka &#xBC0F; &#xB9DD;&#xB9C9; &#xAC1C;&#xBC1C; &#xD558;&#xB294; &#xB3D9;&#xC548; mdkb&#xC758; &#xD734;&#xB300; &#xC2DD; &#xBC0F; &#xD3EC;&#xD1A0; &#xB9AC;&#xC149;&#xD130; &#xC911;&#xC0DD;&#xC758; &#xCD08;&#xAE30;, &#xC99D;&#xC2DD; &#xB2E8;&#xACC4;&#xB97C; &#xC124;&#xBA85;&#xD569;&#xB2C8;&#xB2E4;. &#xACB0;&#xACFC; &#xBC30;&#xC544;&#xC640; &#xC560;&#xBC8C;&#xB808; &#xB9DD;&#xB9C9;&#xC5D0;&#xC11C; mdka &#xBC0F; mdkb&#xC5D0;&#xC11C; &#xD45C;&#xD604; &#xB418;&#xB294; &#xC904;&#xAE30; &#xC138;&#xD3EC;, &#xB9DD;&#xB9C9; progenitors &#xBC0F; &#xC2E0;&#xACBD; &#xB450; &#xBD84;&#xC790;&#xC5D0; &#xB300; &#xD55C; &#xB2E4;&#xC591; &#xD55C; &#xAE30;&#xB2A5;&#xC744; &#xC81C;&#xC548; &#xD558;&#xB294; &#xB3C5;&#xD2B9;&#xD55C; &#xD328;&#xD134;&#xC758; &#xD45C;&#xC2DC;. &#xAC00;&#xB85C; &#xC140;&#xACFC; &#xBC29;&#xC9C0;&#xD560; &#xBB90;&#xB7EC; &#xBA85;&#xACFC; neurogenic &#xADF8;&#xB4E4;&#xC758; &#xC790;&#xC190;&#xC5D0; coexpressed&#xB294; &#xB2E4;&#xC74C;&#xACFC; &#xAC19;&#xC740; &#xC131;&#xC778;, mdka &#xBC0F; mdkb&#xC5D0;&#xC11C; &#xB300;&#xB1CC;&#xC758; &#xC120;&#xD0DD;&#xC801; &#xC8FD;&#xC74C;. &#xC774;&#xB7EC;&#xD55C; &#xB370;&#xC774;&#xD130;&#xB294; Mdka &#xBC0F; Mdkb &#xBC30;&#xC544;&#xC640; &#xC131;&#xC219;&#xD55C; &#xB9DD;&#xB9C9;, &#xB9DD;&#xB9C9; &#xC904;&#xAE30; &#xC138;&#xD3EC; &#xD2C8;&#xC0C8;&#xC5D0; &#xC874;&#xC7AC; &#xD558;&#xB294; &#xC694;&#xC778; &#xBC0F; &#xC138;&#xD3EC; &#xD45C;&#xD604; &#xC801;&#xADF9;&#xC801;&#xC73C;&#xB85C; &#xB9DD;&#xB9C9; &#xAC1C;&#xBC1C; &#xBC0F; &#xC7AC;&#xC0DD;&#xC131; &#xD558;&#xB294; &#xB3D9;&#xC548; &#xBCC0;&#xC870; &#xB41C; &#xC2E0;&#xD638;&#xB294; &#xACF5;&#xAC1C;.

Zebrafish&#xC758; &#xB9DD;&#xB9C9; &#xAC1C;&#xBC1C; &#xBC0F; &#xD3EC;&#xD1A0; &#xB9AC;&#xC149;&#xD130; &#xC7AC;&#xC0DD;&#xC131; &#xD558;&#xB294; &#xB3D9;&#xC548; midkine a&#xC640; midkine b &#xC138;&#xD3EC; &#xC2DD;.

En la retina de los tele&#xF3;steos adultos, las c&#xE9;lulas madre se mantienen en dos nichos especializados: la zona marginal ciliar (CMZ) y el microambiente que rodea a las c&#xE9;lulas de M&#xFC;ller para adultos. Recientemente, las c&#xE9;lulas de M&#xFC;ller fueron identificados como las c&#xE9;lulas madre regenerativas en la retina tele&#xF3;steos. Secretados mol&#xE9;culas de se&#xF1;alizaci&#xF3;n que regulan la regeneraci&#xF3;n neuronal en la retina son en gran parte desconocido. En una pantalla de microarrays para descubrir estos factores, hemos identificado midkine-b (mdkb). Midkine es una muy conservadas heparina de uni&#xF3;n del factor de crecimiento con numerosas funciones biol&#xF3;gicas. El genoma del pez cebra codifica dos genes distintos: midkine mdka y mdkb. Aqu&#xED; se describe la expresi&#xF3;n celular de mdka mdkb y durante el desarrollo de la retina y la fase inicial, de proliferaci&#xF3;n de la regeneraci&#xF3;n de los fotorreceptores. Los resultados muestran que en la retina embrionario y larval mdka mdkb y se expresan en c&#xE9;lulas madre, progenitoras de la retina, y las neuronas en distintos patrones que sugieren que las diferentes funciones de las dos mol&#xE9;culas. Despu&#xE9;s de la muerte selectiva de los fotorreceptores en el adulto, y mdka mdkb se coexpresan en las c&#xE9;lulas horizontales y c&#xE9;lulas gliales proliferan M&#xFC;ller y su progenie neurog&#xE9;nica. Estos datos revelan que Mdka y Mdkb est&#xE1;n se&#xF1;alando los factores presentes en los nichos de c&#xE9;lulas madre de la retina en las retinas, tanto embrionario y adulto, y que su expresi&#xF3;n celular modula de forma activa durante el desarrollo de la retina y la regeneraci&#xF3;n.

Expresi&#xF3;n celular de Midkine-a y b-Midkine En desarrollo de la retina y regeneraci&#xF3;n de los fotorreceptores en el pez cebra

The retina displays numerous processes that follow a circadian rhythm. These processes are coordinated through the direct action of light on photoreceptive molecules and, in the absence of light, through autocrine/paracrine actions of extracellular neuromodulators. We previously described the expression of the genes encoding the secreted heparin-binding growth factors, midkine-a (mdka) and midkine-b (mdkb), in the retina of the zebrafish. Here, we provide evidence that the expression of mdka and mdkb follows a daily rhythm, which is independent of the presence or absence of light, and we propose that the expression of mdka is regulated by the circadian clock. Both qualitative and quantitative measures show that for mdka, the levels of mRNA and protein decrease during the night and increase during the subjective day. Qualitative measures show that the expression of mdkb increases during the second half of the subjective night and decreases during the second half of the subjective day. Within horizontal cells, the two midkine paralogs show asynchronous circadian regulation. Though intensely studied in the contexts of physiology and disease, this is the first study to provide evidence for the circadian regulation of midkines in the vertebrate nervous system.

Midkine expression is regulated by the circadian clock in the retina of the zebrafish.

Investigating neuronal and photoreceptor regeneration in the retina of zebra fish has begun to yield insights into both the cellular and molecular means by which this lower vertebrate is able to repair its central nervous system. However, knowledge about the signaling molecules in the local microenvironment of a retinal injury and the transcriptional events they activate during neuronal death and regeneration is still lacking. To identify genes involved in photoreceptor regeneration, we combined light-induced photoreceptor lesions, laser-capture microdissection of the outer nuclear layer (ONL) and analysis of gene expression to characterize transcriptional changes for cells in the ONL as photoreceptors die and are regenerated. Using this approach, we were able to characterize aspects of the molecular signature of injured and dying photoreceptors, cone photoreceptor progenitors, and microglia within the ONL. We validated changes in gene expression and characterized the cellular expression for three novel, extracellular signaling molecules that we hypothesize are involved in regulating regenerative events in the retina.

Identification of the molecular signatures integral to regenerating photoreceptors in the retina of the zebra fish.

Regulation of c-Fos transcription by GH is mediated by CCAAT/enhancer binding protein β (C/EBPβ). This study examines the role of C/EBPβ in mediating GH activation of other early response genes, including Cyr61, Btg2, Socs3, Zfp36, and Socs1. C/EBPβ depletion using short hairpin RNA impaired responsiveness of these genes to GH, as seen for c-Fos. Rescue with wild-type C/EBPβ led to GH-dependent recruitment of the coactivator p300 to the c-Fos promoter. In contrast, rescue with C/EBPβ mutated at the ERK phosphorylation site at T188 failed to induce GH-dependent recruitment of p300, indicating that ERK-mediated phosphorylation of C/EBPβ at T188 is required for GH-induced recruitment of p300 to c-Fos. GH also induced the occupancy of phosphorylated C/EBPβ and p300 on Cyr61, Btg2, and Socs3 at predicted C/EBP-cAMP response element-binding protein motifs in their promoters. Consistent with a role for ERKs in GH-induced expression of these genes, treatment with U0126 to block ERK phosphorylation inhibited their GH-induced expression. In contrast, GH-dependent expression of Zfp36 and Socs1 was not inhibited by U0126. Thus, induction of multiple early response genes by GH in 3T3-F442A cells is mediated by C/EBPβ. A subset of these genes is regulated similarly to c-Fos, through a mechanism involving GH-stimulated ERK 1/2 activation, phosphorylation of C/EBPβ, and recruitment of p300. Overall, these studies suggest that C/EBPβ, like the signal transducer and activator of transcription proteins, regulates multiple genes in response to GH.

C/EBPβ mediates growth hormone-regulated expression of multiple target genes.

The pineal gland is a neuroendocrine organ of the brain. Its main task is to synthesize and secrete melatonin, a nocturnal hormone with diverse physiological functions. This review will focus on the central and pineal mechanisms in generation of mammalian pineal rhythmicity including melatonin production. In particular, this review covers the following topics: (1) local control of serotonin and melatonin rhythms; (2) neurotransmitters involved in central control of melatonin; (3) plasticity of the neural circuit controlling melatonin production; (4) role of clock genes in melatonin formation; (5) phase control of pineal rhythmicity; (6) impact of light at night on pineal rhythms; and (7) physiological function of the pineal rhythmicity.

Circadian regulation of pineal gland rhythmicity.

The two major classes of activity-dependent neuroplasticity predict different consequences of activity alteration on circuit response. Hebbian plasticity (positive feedback) posits that alteration of neuronal activity causes a parallel response within a circuit. In contrast, homeostatic plasticity (negative feedback) predicts that altering neuronal activity results in compensatory responses within a circuit. The relative roles of these modes of plasticity in vivo are unclear, since neuronal circuits are difficult to manipulate in the intact organism. In this study, we tested the in vivo effects of activity deprivation in the superior cervical ganglion-pineal circuit of adult rats, which can be noninvasively silenced by exposing animals to constant light. We demonstrated that total deprivation of sympathetic activity markedly decreased the presence of axonal proteins in the pineal and reduced the density and thickness of sympathetic axonal arbors. In addition, we demonstrated that sympathetic inactivity eliminated pineal function and markedly decreased pineal expression of neurotrophins. Administration of β-adrenergic agonist restored the expression of presynaptic and postsynaptic proteins. Furthermore, compensatory axonal growth through collateral sprouting, normally seen following unilateral denervation of the pineal, was profoundly impaired in the absence of neural activity. Thus, these data suggest that sympathetic axonal terminals are maintained by neural activity that induces neurotrophins, which may act through a retrograde mechanism to preserve the integrity of axonal arbors via a positive feedback loop. Conversely, by using Hebbian-like neuroplasticity, silent yet intact circuits enter a hibernation mode marked by reduction of presynaptic axonal structures and dramatically reduced postsynaptic expression of neurotrophins.

Transsynaptic activity-dependent regulation of axon branching and neurotrophin expression in vivo.

Midkine is a small heparin binding growth factor expressed in numerous tissues during development. The unique midkine gene in mammals has two paralogs in zebrafish: midkine-a (mdka) and midkine-b (mdkb). In the zebrafish retina, during both larval development and adult photoreceptor regeneration, mdka is expressed in retinal stem and progenitor cells and functions as a molecular component of the retina's stem cell niche. In this study, loss-of-function and conditional overexpression were used to investigate the function of Mdka in the retina of the embryonic zebrafish.

Midkine-A functions upstream of Id2a to regulate cell cycle kinetics in the developing vertebrate retina.

As glioma cells infiltrate the brain they become associated with various microanatomic brain structures such as blood vessels, white matter tracts, and brain parenchyma. How these distinct invasion patterns coordinate tumor growth and influence clinical outcomes remain poorly understood. We have investigated how perivascular growth affects glioma growth patterning and response to antiangiogenic therapy within the highly vascularized brain. Orthotopically implanted rodent and human glioma cells are shown to commonly invade and proliferate within brain perivascular space. This form of brain tumor growth and invasion is also shown to characterize de novo generated endogenous mouse brain tumors, biopsies of primary human glioblastoma (GBM), and peripheral cancer metastasis to the human brain. Perivascularly invading brain tumors become vascularized by normal brain microvessels as individual glioma cells use perivascular space as a conduit for tumor invasion. Agent-based computational modeling recapitulated biological perivascular glioma growth without the need for neoangiogenesis. We tested the requirement for neoangiogenesis in perivascular glioma by treating animals with angiogenesis inhibitors bevacizumab and DC101. These inhibitors induced the expected vessel normalization, yet failed to reduce tumor growth or improve survival of mice bearing orthotopic or endogenous gliomas while exacerbating brain tumor invasion. Our results provide compelling experimental evidence in support of the recently described failure of clinically used antiangiogenics to extend the overall survival of human GBM patients.

Mechanisms of glioma formation: iterative perivascular glioma growth and invasion leads to tumor progression, VEGF-independent vascularization, and resistance to antiangiogenic therapy.

Article	Year
Multiple mechanisms of growth hormone-regulated gene transcription. Molecular genetics and metabolism\| PubMed ID: 17129742	2007
Cellular expression of midkine-a and midkine-b during retinal development and photoreceptor regeneration in zebrafish. The Journal of comparative neurology\| PubMed ID: 19263476	2009
Midkine expression is regulated by the circadian clock in the retina of the zebrafish. Visual neuroscience\| PubMed ID: 19860997	2009
Identification of the molecular signatures integral to regenerating photoreceptors in the retina of the zebra fish. Journal of ocular biology, diseases, and informatics\| PubMed ID: 20072637	2008
C/EBPβ mediates growth hormone-regulated expression of multiple target genes. Molecular endocrinology (Baltimore, Md.)\| PubMed ID: 21292824	2011
Circadian regulation of pineal gland rhythmicity. Molecular and cellular endocrinology\| PubMed ID: 21782887	2012
Transsynaptic activity-dependent regulation of axon branching and neurotrophin expression in vivo. The Journal of neuroscience : the official journal of the Society for Neuroscience\| PubMed ID: 21900550	2011
Midkine-A functions upstream of Id2a to regulate cell cycle kinetics in the developing vertebrate retina. Neural development\| PubMed ID: 23111152	2012
Mechanisms of glioma formation: iterative perivascular glioma growth and invasion leads to tumor progression, VEGF-independent vascularization, and resistance to antiangiogenic therapy. Neoplasia (New York, N.Y.)\| PubMed ID: 25117977	2014

Anda-Alexandra Calinescu

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