spatial-temporal-analysis-of-fieldwise-flow-in-microvasculature

Spatial Temporal Analysis of Fieldwise Flow in Microvasculature

Changes in blood flow velocity and distribution are vital in maintaining tissue and organ perfusion in response to varying cellular needs. Further, ...

Indiana University

&#x80BE;&#x5FAE;&#x8840;&#x7BA1;&#x5185;&#x76AE;&#x7EC6;&#x80DE;&#x635F;&#x4F24;&#x7684;&#x75C5;&#x7406;&#x751F;&#x7406;&#x7F3A;&#x8840;&#x6027;&#x6025;&#x6027;&#x80BE;&#x529F;&#x80FD;&#x8870;&#x7AED; (ARF) &#x7684;&#x4F5C;&#x7528;&#x4ECD;&#x7136;&#x5F88;&#x5927;&#x7A0B;&#x5EA6;&#x4E0A;&#x672A;&#x77E5;&#x3002;&#x6CA1;&#x6709;&#x4E00;&#x81F4;&#x7684;&#x5F62;&#x6001;&#x5B66;&#x53D8;&#x5316;&#x6709;&#x88AB;&#x5F52;&#x56E0;&#x4E8E;&#x56E0;&#x7F3A;&#x8840;&#x518D;&#x704C;&#x6CE8;&#x635F;&#x4F24;&#x80BE;&#x5FAE;&#x8840;&#x7BA1;&#x7684;&#x5185;&#x76AE;&#x7EC6;&#x80DE;&#x3002;&#x56E0;&#x6B64;&#xFF0C;&#x8FD9;&#x9879;&#x7814;&#x7A76;&#x7684;&#x76EE;&#x7684;&#x662F;&#x68C0;&#x67E5;&#x751F;&#x5316;&#x6807;&#x5FD7;&#x7269;&#x8840;&#x7BA1;&#x5185;&#x76AE;&#x635F;&#x4F24;&#x548C;&#x556E;&#x9F7F;&#x52A8;&#x7269;&#x6A21;&#x578B;&#x7F3A;&#x8840;&#x6027;&#x6025;&#x6027;&#x80BE;&#x529F;&#x80FD;&#x8870;&#x7AED;&#x4E2D;&#x80BE;&#x5FAE;&#x8840;&#x7BA1;&#x5185;&#x76AE;&#x7EC6;&#x80DE;&#x7684;&#x5F62;&#x6001;&#x53D8;&#x5316;&#x3002;&#x5FAA;&#x73AF;&#x8840;&#x53CB;&#x75C5;&#x56E0;&#x5B50; (vWF) &#x88AB;&#x8861;&#x91CF;&#x4F5C;&#x4E3A;&#x8840;&#x7BA1;&#x5185;&#x76AE;&#x635F;&#x4F24;&#x7684;&#x6807;&#x8BB0;&#x3002;&#x4E8C;&#x5341;&#x56DB;&#x4E2A;&#x5C0F;&#x65F6;&#x540E;&#x7F3A;&#x8840;&#xFF0C;&#x5FAA;&#x73AF;&#x8840;&#x53CB;&#x75C5;&#x8FBE;&#x5230; 124%&#x8D85;&#x8FC7;&#x6BD4;&#x8F83;&#x57FA;&#x51C6;&#x503C; (P = 0.001)&#x3002;FVB-TIE2/GFP &#x9F20;&#x6807;&#x88AB;&#x7528;&#x6765;&#x672C;&#x5730;&#x5316;&#x80BE;&#x5FAE;&#x8840;&#x7BA1;&#x5185;&#x76AE;&#x7EC6;&#x80DE;&#x7684;&#x5F62;&#x6001;&#x53D8;&#x5316;&#x3002;&#x7F3A;&#x8840;&#x4E4B;&#x540E;&#x7ACB;&#x5373;, &#x6709; F-&#x808C;&#x52A8;&#x86CB;&#x767D;&#x805A;&#x5408;&#x4E2D;&#x80BE;&#x5FAE;&#x8840;&#x7BA1;&#x5185;&#x76AE;&#x9AD3;&#x8D28;&#x4EA4;&#x754C;&#x5904;&#x8840;&#x7BA1;&#x5185;&#x76AE;&#x7EC6;&#x80DE;&#x7684;&#x57FA;&#x5E95;&#x548C;&#x57FA;&#x5E95;&#x5916;&#x4FA7;&#x65B9;&#x9762;&#x663E;&#x8457;&#x7684;&#x589E;&#x52A0;&#x3002;&#x540E;&#x518D;&#x704C;&#x6CE8; 24 h&#xFF0C;F-&#x808C;&#x52A8;&#x86CB;&#x767D;&#x67D3;&#x8272;&#x7684;&#x6A21;&#x5F0F;&#x662F;&#x5728;&#x751F;&#x7406;&#x6761;&#x4EF6;&#x4E0B;&#x89C2;&#x5BDF;&#x5230;&#x7684;&#x66F4;&#x76F8;&#x4F3C;&#x3002;&#x6B64;&#x5916;&#xFF0C;&#x5B8C;&#x6574;&#x7684;&#x80BE;&#x5FAE;&#x8840;&#x7BA1;&#xFF0C;&#x591A;&#x5F62;&#x6838;&#x767D;&#x7EC6;&#x80DE;&#x5BFC;&#x81F4;&#x4EA4;&#x754C;&#x5904;&#x7684;&#x53D8;&#x5316;&#x4E2D;&#x8840;&#x7BA1;&#x5185;&#x76AE;&#x7EC6;&#x80DE;&#x9499;&#x7C98;&#x86CB;&#x767D;&#x7EC4;&#x5316;&#x67D3;&#x8272;&#xFF0C;&#x672C;&#x5730;&#x5316;&#x7684;&#x635F;&#x5931;&#x6240;&#x793A;&#x53D1;&#x73B0;&#x540E;&#x518D;&#x704C;&#x6CE8; 24 h&#x3002;&#x8FD9;&#x4E00;&#x89C2;&#x5BDF;&#x6682;&#x65F6;&#x76F8;&#x5173;&#x6700;&#x5927;&#x7A0B;&#x5EA6;&#x7684;&#x80BE;&#x5FAE;&#x8840;&#x7BA1;&#x901A;&#x900F;&#x6027;&#x7F3A;&#x635F;&#x6240;&#x786E;&#x5B9A;&#x4F7F;&#x7528;&#x8367;&#x5149; dextrans &#x548C;&#x53CC;&#x5149;&#x5B50;&#x6D3B;&#x4F53;&#x6210;&#x50CF;&#x3002;&#x603B;&#x4E4B;&#xFF0C;&#x8FD9;&#x4E9B;&#x7ED3;&#x679C;&#x8868;&#x660E;&#x80BE;&#x8840;&#x7BA1;&#x5185;&#x76AE;&#x635F;&#x4F24;&#x53D1;&#x751F;&#x5728;&#x7F3A;&#x8840;&#x6027;&#x6025;&#x6027;&#x80BE;&#x529F;&#x80FD;&#x8870;&#x7AED;&#x548C;&#x53EF;&#x80FD;&#x5728;&#x7F3A;&#x8840;&#x6027;&#x6025;&#x6027;&#x80BE;&#x529F;&#x80FD;&#x8870;&#x7AED;&#x7684;&#x75C5;&#x7406;&#x751F;&#x7406;&#x5B66;&#x4E2D;&#x53D1;&#x6325;&#x91CD;&#x8981;&#x4F5C;&#x7528;&#x3002;

&#x80BE;&#x5FAE;&#x8840;&#x7BA1;&#x5185;&#x76AE;&#x7EC6;&#x80DE;&#x635F;&#x4F24;&#x540E;&#x7F3A;&#x8840;&#x6539;&#x53D8;&#x5C4F;&#x969C;&#x529F;&#x80FD;&#x3002;

The role of renal microvascular endothelial cell injury in the pathophysiology of ischemic acute renal failure (ARF) remains largely unknown. No consistent morphological alterations have been ascribed to the endothelium of the renal microvasculature as a result of ischemia-reperfusion injury. Therefore, the purpose of this study was to examine biochemical markers of endothelial injury and morphological changes in the renal microvascular endothelium in a rodent model of ischemic ARF. Circulating von Willebrand factor (vWF) was measured as a marker of endothelial injury. Twenty-four hours after ischemia, circulating vWF peaked at 124% over baseline values (P = 0.001). The FVB-TIE2/GFP mouse was utilized to localize morphological changes in the renal microvascular endothelium. Immediately after ischemia, there was a marked increase in F-actin aggregates in the basal and basolateral aspect of renal microvascular endothelial cells in the corticomedullary junction. After 24 h of reperfusion, the pattern of F-actin staining was more similar to that observed under physiological conditions. In addition, alterations in the integrity of the adherens junctions of the renal microvasculature, as demonstrated by loss of localization in vascular endothelial cadherin immunostaining, were observed after 24 h of reperfusion. This observation temporally correlated with the greatest extent of permeability defect in the renal microvasculature as identified using fluorescent dextrans and two-photon intravital imaging. Taken together, these findings indicate that renal vascular endothelial injury occurs in ischemic ARF and may play an important role in the pathophysiology of ischemic ARF.

Injury of the renal microvascular endothelium alters barrier function after ischemia.

Le r&#xF4;le de la fonction r&#xE9;nale des l&#xE9;sions des cellules endoth&#xE9;liales microvasculaires dans la physiopathologie de l&#x26;#39;insuffisance r&#xE9;nale isch&#xE9;mique aigu&#xEB; (IRA) reste largement inconnu. Aucune modification coh&#xE9;rentes morphologiques ont &#xE9;t&#xE9; attribu&#xE9;s &#xE0; l&#x26;#39;endoth&#xE9;lium des microvaisseaux r&#xE9;nale &#xE0; la suite de l&#x26;#39;isch&#xE9;mie-reperfusion. Par cons&#xE9;quent, le but de cette &#xE9;tude &#xE9;tait d&#x26;#39;examiner les marqueurs biochimiques de l&#xE9;sion endoth&#xE9;liale et les changements morphologiques dans l&#x26;#39;endoth&#xE9;lium microvasculaire r&#xE9;nale dans un mod&#xE8;le rongeur de la isch&#xE9;mique ARF. De circulation du facteur von Willebrand (vWF) a &#xE9;t&#xE9; mesur&#xE9;e comme un marqueur de l&#xE9;sion endoth&#xE9;liale. Vingt-quatre heures apr&#xE8;s une isch&#xE9;mie, circulant vWF a culmin&#xE9; &#xE0; 124% par rapport aux valeurs de base (p = 0,001). La souris a &#xE9;t&#xE9; utilis&#xE9; FVB-TIE2/GFP de localiser les changements morphologiques de l&#x26;#39;endoth&#xE9;lium microvasculaire r&#xE9;nale. Imm&#xE9;diatement apr&#xE8;s l&#x26;#39;isch&#xE9;mie, il y avait une augmentation marqu&#xE9;e de la F-actine agr&#xE9;gats dans l&#x26;#39;aspect de base et basolat&#xE9;rale des cellules endoth&#xE9;liales microvasculaires r&#xE9;nales &#xE0; la jonction cortico-m&#xE9;dullaire. Apr&#xE8;s 24 h de reperfusion, le mod&#xE8;le de F-actine coloration &#xE9;tait plus semblable &#xE0; celle observ&#xE9;e dans des conditions physiologiques. En outre, les alt&#xE9;rations de l&#x26;#39;int&#xE9;grit&#xE9; des jonctions adherens de la microvascularisation r&#xE9;nale, comme l&#x26;#39;a d&#xE9;montr&#xE9; par la perte de la localisation en immunomarquage cadh&#xE9;rine de l&#x26;#39;endoth&#xE9;lium vasculaire, ont &#xE9;t&#xE9; observ&#xE9;s apr&#xE8;s 24 h de reperfusion. Cette observation temporellement corr&#xE9;l&#xE9;e avec la plus grande mesure de d&#xE9;faut de perm&#xE9;abilit&#xE9; dans le syst&#xE8;me microvasculaire r&#xE9;nale identifi&#xE9;s &#xE0; l&#x26;#39;aide dextranes fluorescents et &#xE0; deux photons d&#x26;#39;imagerie intravitale. Pris ensemble, ces r&#xE9;sultats indiquent que les blessures de l&#x26;#39;endoth&#xE9;lium vasculaire r&#xE9;nale survient dans isch&#xE9;mique ARF et peut jouer un r&#xF4;le important dans la physiopathologie de l&#x26;#39;isch&#xE9;mie ARF.

Blessure de la fonction microvasculaire endoth&#xE9;lium barri&#xE8;re r&#xE9;nale Alters apr&#xE8;s une isch&#xE9;mie

Verletzungen der Nieren mikrovaskul&#xE4;re Endothel ver&#xE4;ndert Barrierefunktion nach Isch&#xE4;mie.

Il ruolo della lesione renale delle cellule endoteliali Microvascolari nella fisiopatologia dell&#39;insufficienza renale acuta ischemica (ARF) rimane in gran parte sconosciuto. Non coerente alterazioni morfologiche sono state attribuite per l&#39;endotelio del microvasculature renale a seguito di danno da ischemia-riperfusione. Pertanto, lo scopo di questo studio era di esaminare i marcatori biochimici di danno endoteliale e cambiamenti morfologici nell&#39;endotelio microvascolare renale in un modello di roditore di ARF ischemico. Circolanti von Willebrand factor (vWF) &egrave; stata misurata come marker di danno endoteliale. Ventiquattro ore dopo ischemia, circolanti vWF raggiunse 124% sopra i valori di base (P = 0,001). Il mouse FVB-TIE2/GFP &egrave; stato utilizzato per localizzare i cambiamenti morfologici nell&#39;endotelio microvascolare renale. Immediatamente dopo ischemia, c&#39;&egrave; stato un marcato aumento in aggregati di F-actina all&#39;aspetto delle cellule endoteliali Microvascolari renali nella giunzione cortico basale e basolaterale. Dopo 24 h di riperfusione, il pattern di colorazione di F-actina &egrave; stato pi&ugrave; simile a quello osservato in condizioni fisiologiche. Inoltre, alterazioni dell&#39;integrit&agrave; delle giunzioni adherens del microvasculature renale, come dimostrato dalla perdita della localizzazione in vascular endothelial caderina immunostaining, sono stati osservati dopo 24 h di riperfusione. Questa osservazione temporalmente correlata con la massima estensione del difetto di permeabilit&agrave; nel microvasculature renale identificato usando due-fotone intravital imaging e destrani fluorescente. Presi insieme, questi risultati indicano che danno endoteliale vascolare renale si verifica in ARF ischemica e pu&ograve; svolgere un ruolo importante nella fisiopatologia dell&#39;ARF ischemico.

Lesioni dell&#39;endotelio microvascolare renale altera la funzione barriera dopo ischemia.

&#x865A;&#x8840;&#x6027;&#x6025;&#x6027;&#x814E;&#x4E0D;&#x5168;&#xFF08;ARF&#xFF09;&#x306E;&#x75C5;&#x614B;&#x751F;&#x7406;&#x306B;&#x304A;&#x3051;&#x308B;&#x814E;&#x5FAE;&#x5C0F;&#x8840;&#x7BA1;&#x5185;&#x76AE;&#x7D30;&#x80DE;&#x50B7;&#x5BB3;&#x306E;&#x5F79;&#x5272;&#x306F;&#x307B;&#x3068;&#x3093;&#x3069;&#x4E0D;&#x660E;&#x306E;&#x307E;&#x307E;&#x3067;&#x3059;&#x3002;&#x4E00;&#x8CAB;&#x3057;&#x305F;&#x5F62;&#x614B;&#x5B66;&#x7684;&#x5909;&#x5316;&#x306F;&#x865A;&#x8840;&#x518D;&#x704C;&#x6D41;&#x969C;&#x5BB3;&#x306E;&#x7D50;&#x679C;&#x3068;&#x3057;&#x3066;&#x814E;&#x5FAE;&#x5C0F;&#x8840;&#x7BA1;&#x306E;&#x5185;&#x76AE;&#x7D30;&#x80DE;&#x306B;&#x5E30;&#x3055;&#x308C;&#x3066;&#x3044;&#x307E;&#x305B;&#x3093;&#x3002;&#x3057;&#x305F;&#x304C;&#x3063;&#x3066;&#x3001;&#x672C;&#x7814;&#x7A76;&#x306E;&#x76EE;&#x7684;&#x306F;&#x3001;&#x5185;&#x76AE;&#x50B7;&#x5BB3;&#x3001;&#x865A;&#x8840;&#x6027;ARF&#x306E;&#x9F67;&#x6B6F;&#x985E;&#x30E2;&#x30C7;&#x30EB;&#x306B;&#x304A;&#x3051;&#x308B;&#x814E;&#x5FAE;&#x5C0F;&#x8840;&#x7BA1;&#x5185;&#x76AE;&#x7D30;&#x80DE;&#x306E;&#x5F62;&#x614B;&#x5B66;&#x7684;&#x5909;&#x5316;&#x306E;&#x751F;&#x5316;&#x5B66;&#x7684;&#x30DE;&#x30FC;&#x30AB;&#x30FC;&#x3092;&#x691C;&#x8A0E;&#x3057;&#x305F;&#x3002;&#x5FAA;&#x74B0;&#x30D5;&#x30A9;&#x30F3;&#x30F4;&#x30A3;&#x30EC;&#x30D6;&#x30E9;&#x30F3;&#x30C9;&#x56E0;&#x5B50;&#xFF08;vWF&#xFF09;&#x306F;&#x8840;&#x7BA1;&#x5185;&#x76AE;&#x50B7;&#x5BB3;&#x306E;&#x30DE;&#x30FC;&#x30AB;&#x30FC;&#x3068;&#x3057;&#x3066;&#x6E2C;&#x5B9A;&#x3057;&#x305F;&#x3002;&#x865A;&#x8840;24&#x6642;&#x9593;&#x5F8C;&#x3001;&#x5FAA;&#x74B0;vWF&#x306F;&#x57FA;&#x6E96;&#x5024;&#x4EE5;&#x4E0A;&#x306E;124&#x30D1;&#x30FC;&#x30BB;&#x30F3;&#x30C8;&#xFF08;P = 0.001&#xFF09;&#x3067;&#x30D4;&#x30FC;&#x30AF;&#x306B;&#x9054;&#x3057;&#x305F;&#x3002; FVB-TIE2/GFP&#x30DE;&#x30A6;&#x30B9;&#x306F;&#x814E;&#x5FAE;&#x5C0F;&#x8840;&#x7BA1;&#x5185;&#x76AE;&#x7D30;&#x80DE;&#x306E;&#x5F62;&#x614B;&#x5B66;&#x7684;&#x5909;&#x5316;&#x3092;&#x30ED;&#x30FC;&#x30AB;&#x30E9;&#x30A4;&#x30BA;&#x3059;&#x308B;&#x305F;&#x3081;&#x306B;&#x5229;&#x7528;&#x3055;&#x308C;&#x305F;&#x3002;&#x3059;&#x3050;&#x306B;&#x865A;&#x8840;&#x5F8C;&#x3001;&#x76AE;&#x9AC4;&#x63A5;&#x5408;&#x306B;&#x304A;&#x3051;&#x308B;&#x814E;&#x5FAE;&#x5C0F;&#x8840;&#x7BA1;&#x5185;&#x76AE;&#x7D30;&#x80DE;&#x306E;&#x57FA;&#x5E95;&#x3068;&#x57FA;&#x5E95;&#x9762;&#x3067;F-&#x30A2;&#x30AF;&#x30C1;&#x30F3;&#x51DD;&#x96C6;&#x4F53;&#x306E;&#x9855;&#x8457;&#x306A;&#x5897;&#x52A0;&#x304C;&#x3042;&#x3063;&#x305F;&#x3002;&#x518D;&#x704C;&#x6D41;24&#x6642;&#x9593;&#x5F8C;&#x3001;F-&#x30A2;&#x30AF;&#x30C1;&#x30F3;&#x67D3;&#x8272;&#x306E;&#x30D1;&#x30BF;&#x30FC;&#x30F3;&#x306F;&#x3001;&#x751F;&#x7406;&#x7684;&#x6761;&#x4EF6;&#x4E0B;&#x3067;&#x89B3;&#x5BDF;&#x3055;&#x308C;&#x305F;&#x3082;&#x306E;&#x306B;&#x985E;&#x4F3C;&#x3057;&#x3066;&#x3044;&#x305F;&#x3002;&#x3055;&#x3089;&#x306B;&#x3001;&#x3068;&#x3057;&#x3066;&#x8840;&#x7BA1;&#x5185;&#x76AE;&#x30AB;&#x30C9;&#x30D8;&#x30EA;&#x30F3;&#x514D;&#x75AB;&#x67D3;&#x8272;&#x306E;&#x5C40;&#x5728;&#x306E;&#x6D88;&#x5931;&#x306B;&#x3088;&#x3063;&#x3066;&#x793A;&#x3055;&#x814E;&#x5FAE;&#x5C0F;&#x8840;&#x7BA1;&#x7CFB;&#x306E;&#x63A5;&#x7740;&#x63A5;&#x5408;&#x306E;&#x5B8C;&#x5168;&#x6027;&#x306E;&#x5909;&#x5316;&#x306F;&#x3001;&#x518D;&#x704C;&#x6D41;24&#x6642;&#x9593;&#x5F8C;&#x306B;&#x89B3;&#x5BDF;&#x3055;&#x308C;&#x305F;&#x3002;&#x86CD;&#x5149;&#x30C7;&#x30AD;&#x30B9;&#x30C8;&#x30E9;&#x30F3;&#x304A;&#x3088;&#x3073;&#x4E8C;&#x5149;&#x5B50;&#x751F;&#x4F53;&#x30A4;&#x30E1;&#x30FC;&#x30B8;&#x30F3;&#x30B0;&#x3092;&#x7528;&#x3044;&#x3066;&#x540C;&#x5B9A;&#x3057;&#x3001;&#x3053;&#x306E;&#x89B3;&#x6E2C;&#x306F;&#x3001;&#x4E00;&#x6642;&#x7684;&#x306B;&#x814E;&#x5FAE;&#x5C0F;&#x8840;&#x7BA1;&#x306E;&#x900F;&#x904E;&#x6027;&#x306E;&#x6B20;&#x9665;&#x306E;&#x6700;&#x5927;&#x7BC4;&#x56F2;&#x3068;&#x76F8;&#x95A2;&#x3057;&#x3066;&#x3044;&#x305F;&#x3002;&#x307E;&#x3068;&#x3081;&#x308B;&#x3068;&#x3001;&#x3053;&#x308C;&#x3089;&#x306E;&#x6240;&#x898B;&#x306F;&#x3001;&#x814E;&#x8840;&#x7BA1;&#x5185;&#x76AE;&#x50B7;&#x5BB3;&#x3001;&#x865A;&#x8840;&#x6027;ARF&#x3067;&#x767A;&#x751F;&#x3057;&#x3001;&#x865A;&#x8840;&#x6027;ARF&#x306E;&#x75C5;&#x614B;&#x306B;&#x91CD;&#x8981;&#x306A;&#x5F79;&#x5272;&#x3092;&#x679C;&#x305F;&#x3059;&#x53EF;&#x80FD;&#x6027;&#x304C;&#x3042;&#x308B;&#x3053;&#x3068;&#x3092;&#x793A;&#x3057;&#x3066;&#x3044;&#x307E;&#x3059;&#x3002;

&#x865A;&#x8840;&#x5F8C;&#x306E;&#x814E;&#x5FAE;&#x5C0F;&#x8840;&#x7BA1;&#x5185;&#x76AE;&#x7D30;&#x80DE;&#x3092;&#x5909;&#x5316;&#x3055;&#x305B;&#x308B;&#x30D0;&#x30EA;&#x30A2;&#x6A5F;&#x80FD;&#x306E;&#x640D;&#x50B7;

&#xD5C8; &#xD608; &#xC131; &#xAE09;&#xC131; &#xC2E0;&#xBD80;&#xC804; (ARF)&#xC758; &#xC774;&#xC0C1;&#xC5D0;&#xC11C; &#xC2E0;&#xC7A5; microvascular &#xB0B4; &#xD53C; &#xC138;&#xD3EC; &#xC190;&#xC0C1;&#xC758; &#xC5ED;&#xD560;&#xC774; &#xD06C;&#xAC8C; &#xC54C;&#xB824;&#xC9C0;&#xC9C0; &#xC54A;&#xC740; &#xB0A8;&#xC544; &#xC788;&#xC2B5;&#xB2C8;&#xB2E4;. &#xC544;&#xB2C8; &#xC77C;&#xAD00;&#xC131; &#xD615;&#xD0DC;&#xD559; &#xBCC0;&#xACBD; &#xD5C8; &#xD608; reperfusion &#xBD80;&#xC0C1;&#xC73C;&#xB85C; &#xC778;&#xD574; &#xC2E0;&#xC7A5; microvasculature endothelium &#xAD00;&#xCC30; &#xC791;&#xC6A9; &#xB418;&#xC5B4; &#xC788;&#xB2E4;. &#xB530;&#xB77C;&#xC11C;&#xC774; &#xC5F0;&#xAD6C;&#xC758; &#xBAA9;&#xC801;&#xC740; &#xB0B4; &#xD53C; &#xBD80;&#xC0C1; &#xBC0F; &#xD5C8; &#xD608; &#xC131; ARF&#xC758; &#xC950; &#xBAA8;&#xB378;&#xC5D0;&#xC11C; &#xC2E0;&#xC7A5; microvascular endothelium &#xD615;&#xD0DC;&#xD559; &#xBCC0;&#xD654;&#xC758; &#xC0DD; &#xD654; &#xD559;&#xC801; &#xD45C;&#xC2DD; &#xC870;&#xC0AC; &#xB410;&#xB2E4;. &#xC21C;&#xD658; von Willebrand &#xC778;&#xC790; (vWF) &#xB0B4; &#xD53C; &#xC0C1;&#xD574;&#xC758; &#xD45C;&#xC2DD;&#xC73C;&#xB85C; &#xCE21;&#xC815; &#xD588;&#xB2E4;. 24 &#xC2DC;&#xAC04; &#xD6C4;&#xC5D0; &#xAD6D; &#xC18C; &#xBE48; &#xD608;, &#xCD08;&#xAE30; &#xACC4;&#xD68D; &#xAC12;&#xC744; &#xD1B5;&#xD574; 124%&#xB97C; &#xC815;&#xC810;&#xC73C;&#xB85C; vWF &#xC21C;&#xD658; (P = 0.001). FVB-TIE2/GFP &#xB9C8;&#xC6B0;&#xC2A4; &#xC9C0;&#xC5ED;&#xD654; &#xD615;&#xD0DC;&#xD559; &#xBCC0;&#xD654; &#xC2E0;&#xC7A5; microvascular endothelium&#xC5D0; &#xC774;&#xC6A9; &#xB418;&#xC5C8;&#xB2E4;. &#xAD6D; &#xC18C; &#xBE48; &#xD608;, &#xC9C1;&#xD6C4; corticomedullary &#xC811;&#xD569;&#xC5D0;&#xC11C; &#xC2E0;&#xC7A5; microvascular &#xB0B4; &#xD53C; &#xC138;&#xD3EC;&#xC758; &#xAE30;&#xC800; &#xBC0F; basolateral &#xCE21;&#xBA74;&#xC5D0;&#xC11C; F &#xB9D0;&#xB77C; &#xC9D1;&#xACC4;&#xC5D0; &#xD45C;&#xC2DC; &#xB41C; &#xC99D;&#xAC00; &#xD588;&#xB2E4;. Reperfusion&#xC758; 24 &#xC2DC;&#xAC04; &#xD6C4; F &#xB9D0;&#xB77C; &#xC5BC;&#xB8E9;&#xC758; &#xD328;&#xD134; &#xC0DD;&#xB9AC; &#xC801; &#xC870;&#xAC74; &#xD558;&#xC5D0;&#xC11C; &#xAD00;&#xCC30; &#xD558;&#xB294; &#xAC8C; &#xB354; &#xBE44;&#xC2B7; &#xD588;&#xB2E4;. &#xB610;&#xD55C;, &#xC2E0;&#xC7A5; microvasculature&#xC758; adherens &#xC811;&#xD569;&#xBD80;&#xC758; &#xBB34;&#xACB0;&#xC131;&#xC5D0; &#xBCC0;&#xACBD; &#xAC19;&#xC774; &#xD608;&#xAD00; &#xB0B4; &#xD53C; cadherin immunostaining&#xC5D0; &#xC9C0;&#xC5ED;&#xD654;&#xC758; &#xC190;&#xC2E4;&#xC5D0; &#xC758;&#xD574; &#xAD00;&#xCC30; &#xB418;&#xC5C8;&#xB2E4; reperfusion&#xC758; 24 &#xC2DC;&#xAC04; &#xD6C4;. &#xC774; &#xAD00;&#xCC30; &#xD615;&#xAD11; dextrans &#xBC0F; 2 &#xAD11;&#xC790; intravital &#xC774;&#xBBF8;&#xC9D5; &#xC0AC;&#xC6A9; &#xD558; &#xC5EC; &#xC2DD;&#xBCC4; &#xB41C; &#xC2E0;&#xC7A5; microvasculature&#xC5D0; &#xCE68;&#xD22C;&#xC131; &#xACB0;&#xD568;&#xC758; &#xAC00;&#xC7A5; &#xD070; &#xBC94;&#xC704;&#xC640; &#xC77C;&#xC2DC;&#xC801; &#xC0C1;&#xAD00;. &#xD568;&#xAED8; &#xCC0D;&#xC740;, &#xC774;&#xB7EC;&#xD55C; &#xC5F0;&#xAD6C; &#xACB0;&#xACFC; &#xC2E0;&#xC7A5; &#xD608;&#xAD00; &#xB0B4; &#xD53C; &#xBD80;&#xC0C1; &#xD5C8; &#xD608; &#xC131; ARF&#xC5D0;&#xC11C; &#xBC1C;&#xC0DD; &#xD558; &#xACE0; &#xD5C8; &#xD608; &#xC131; ARF&#xC758; &#xC774;&#xC0C1;&#xC5D0; &#xC911;&#xC694; &#xD55C; &#xC5ED;&#xD560;&#xC744; &#xC7AC;&#xC0DD;&#xD560; &#xC218; &#xC788;&#xC2B5;&#xB2C8;&#xB2E4; &#xB098;&#xD0C0;&#xB0C5;&#xB2C8;&#xB2E4;.

&#xC2E0;&#xC7A5; microvascular endothelium &#xBD80;&#xC0C1; &#xD5C8; &#xD608; &#xD6C4; &#xC7A5;&#xBCBD; &#xAE30;&#xB2A5;&#xC744; &#xBCC0;&#xACBD;&#xD569;&#xB2C8;&#xB2E4;.

El papel de la lesi&#xF3;n renal microvascular de las c&#xE9;lulas endoteliales en la fisiopatolog&#xED;a de la isquemia insuficiencia renal aguda (IRA) sigue siendo en gran parte desconocido. No se observaron alteraciones morfol&#xF3;gicas consistentes se han atribuido en el endotelio de la microvasculatura renal como consecuencia de la lesi&#xF3;n por isquemia-reperfusi&#xF3;n. Por lo tanto, el prop&#xF3;sito de este estudio fue examinar los marcadores bioqu&#xED;micos de lesi&#xF3;n endotelial y los cambios morfol&#xF3;gicos en el endotelio microvascular renal en un modelo murino de isquemia IRA. Circulaci&#xF3;n de factor von Willebrand (FVW) se midi&#xF3; como un marcador de lesi&#xF3;n endotelial. Veinticuatro horas despu&#xE9;s de la isquemia, que circula vWF alcanz&#xF3; un m&#xE1;ximo de 124% sobre los valores basales (p = 0,001). El rat&#xF3;n FVB-TIE2/GFP se utiliz&#xF3; para localizar los cambios morfol&#xF3;gicos en el endotelio microvascular renal. Inmediatamente despu&#xE9;s de la isquemia, se produjo un marcado incremento en los agregados F-actina en el aspecto basal y basolateral de las c&#xE9;lulas renales endoteliales microvasculares en la uni&#xF3;n corticomedular. Despu&#xE9;s de 24 h de reperfusi&#xF3;n, el patr&#xF3;n de tinci&#xF3;n F-actina era m&#xE1;s similar a la observada en condiciones fisiol&#xF3;gicas. Adem&#xE1;s, las alteraciones en la integridad de las uniones adherentes de la microvasculatura renal, como se demuestra por la p&#xE9;rdida de la localizaci&#xF3;n en inmunotinci&#xF3;n vascular cadherina endotelial, se observaron despu&#xE9;s de 24 h de reperfusi&#xF3;n. Esta observaci&#xF3;n temporal relacionada con el mayor grado de defecto de la permeabilidad en la microvasculatura renal, identificados con dextranos fluorescentes y de dos fotones de imagen intravital. En conjunto, estos hallazgos indican que la lesi&#xF3;n renal endotelial vascular isqu&#xE9;mico se produce en la insuficiencia renal aguda y puede desempe&#xF1;ar un papel importante en la fisiopatolog&#xED;a de la isquemia IRA.

Lesi&#xF3;n de la funci&#xF3;n microvascular endotelio renal altera la barrera despu&#xE9;s de la isquemia

Tetracyclines exhibit significant anti-inflammatory properties, inhibit matrix metalloproteinases (MMPs), and are protective in models of ischemia-reperfusion injury (IRI). Both inflammatory cascades and MMP activation have been demonstrated to modulate microvascular permeability. Because increased microvascular permeability occurs during IRI in a variety of organ systems including the kidney, we hypothesized that minocycline, a semisynthetic tetracycline, would diminish microvascular leakage during renal IRI. To test this hypothesis, we used intravital 2-photon microscopy to examine leakage of fluorescent dextrans from the vasculature in a rodent model of IRI. Minocycline significantly reduced the extent of dextran (500 kDa) leakage from the renal microvasculature 24 h after ischemia. Although minocycline diminished leukocyte accumulation in the kidney following ischemia, areas of leukocyte accumulation did not correlate with areas of microvascular permeability in either the saline- or minocycline-pretreated animals. Minocycline diminished the perivascular increase in MMP-2 and MMP-9, as well as the increase in MMP-2 activity 24 h after ischemia. ABT-518, a specific inhibitor of MMP-2 and MMP-9, also significantly reduced the extent of dextran (500 kDa) leakage from the renal microvasculature 24 h after ischemia. Our results indicate that minocycline mitigates the renal microvascular permeability defect following IRI. This effect is spatially distinct from the effect of minocycline on leukocyte accumulation and may be related to diminished activity of MMPs on the integrity of the perivascular matrix.

Minocycline reduces renal microvascular leakage in a rat model of ischemic renal injury.

T&eacute;tracyclines pr&eacute;sentent d&#39;importantes propri&eacute;t&eacute;s anti-inflammatoires, inhibent les m&eacute;talloprot&eacute;inases matricielles (MMP) et sont protecteurs dans les mod&egrave;les d&#39;isch&eacute;mie-reperfusion (IRI). Les cascades inflammatoires et activation de la MMP ont &eacute;t&eacute; d&eacute;montr&eacute;s pour moduler la perm&eacute;abilit&eacute; microvasculaire. Parce que l&#39;augmentation de la perm&eacute;abilit&eacute; microvasculaire se produit au cours de l&#39;IRI, dans une vari&eacute;t&eacute; de syst&egrave;mes d&#39;organes y compris les reins, nous l&#39;hypoth&egrave;se que la minocycline, une tetracycline semi-synth&eacute;tique, diminuerait microvasculaire fuite au cours de l&#39;IRI r&eacute;nale. Pour tester cette hypoth&egrave;se, nous avons utilis&eacute; la microscopie intravitale biphotonique &agrave; examiner la fuite des dextrans fluorescents de la vascularisation dans un mod&egrave;le de rongeur d&#39;IRI. Minocycline a consid&eacute;rablement r&eacute;duit l&#39;&eacute;tendue de la fuite de dextran (500 kDa) de la microcirculation r&eacute;nale 24h apr&egrave;s isch&eacute;mie. Bien que minocycline diminu&eacute; l&#39;accumulation de leucocytes dans le rein apr&egrave;s isch&eacute;mie, zones d&#39;accumulation de leucocytes ne sont pas corr&eacute;l&eacute; avec les domaines de la perm&eacute;abilit&eacute; microvasculaire soit dans les animaux d&#39;une solution saline ou minocycline-pr&eacute;trait&eacute;s. La minocycline a diminu&eacute; l&#39;augmentation p&eacute;rivasculaires de MMP-9 et de MMP-2, ainsi que l&#39;augmentation de l&#39;activit&eacute; des MMP-2 h 24 apr&egrave;s isch&eacute;mie. ABT-518, un inhibiteur sp&eacute;cifique de la MMP-2 et MMP-9, &eacute;galement sensiblement r&eacute;duit l&#39;ampleur de la fuite de dextran (500 kDa) de la microcirculation r&eacute;nale 24h apr&egrave;s isch&eacute;mie. Nos r&eacute;sultats indiquent que la minocycline att&eacute;nue le d&eacute;faut de la perm&eacute;abilit&eacute; microvasculaire r&eacute;nale suite IRI. Cet effet est spatialement distinct de l&#39;effet de la minocycline sur l&#39;accumulation de leucocyte et peut &ecirc;tre li&eacute; &agrave; l&#39;activit&eacute; r&eacute;duite des MPM sur l&#39;int&eacute;grit&eacute; de la matrice p&eacute;rivasculaires.

Minocycline r&eacute;duit de fuite r&eacute;nale microvasculaire dans un mod&egrave;le de rat de l&eacute;sion r&eacute;nale isch&eacute;mique.

Tetracicline presentano notevoli propriet&agrave; anti-infiammatorie, inibiscono metalloproteinasi della matrice (MMP) e sono protettive in modelli di danno da ischemia-riperfusione (IRI). Sia cascata infiammatoria e attivazione di MMP sono state dimostrate per modulare la permeabilit&agrave; microvascolare. Perch&eacute; l&#39;aumento della permeabilit&agrave; microvascolare si verifica durante l&#39;IRI in una variet&agrave; di sistemi di organi tra cui il rene, abbiamo ipotizzato che minociclina, un semisintetico tetraciclina, diminuirebbe microvascolare perdite durante renale IRI. Per verificare questa ipotesi, abbiamo usato intravital 2-fotone microscopia per esaminare la fuoriuscita di destrani fluorescente dal sistema vascolare in un modello di roditore dell&#39;IRI. Minociclina ha ridotto significativamente l&#39;entit&agrave; della perdita di destrano (500 kDa) dal microvasculature renale 24h dopo ischemia. Sebbene minociclina diminuito accumulo dei leucociti nel rene dopo ischemia, zone di accumulo dei leucociti non correlare con zone di permeabilit&agrave; microvascolare in entrambi gli animali pretrattati fisiologica o minociclina. Minociclina ha diminuito l&#39;aumento perivascolare MMP-2 e MMP-9, cos&igrave; come l&#39;aumento dell&#39;attivit&agrave; di MMP-2 24 h dopo ischemia. ABT-518, un inibitore specifico di MMP-2 e MMP-9, anche significativamente ridotto l&#39;entit&agrave; della perdita di destrano (500 kDa) dal microvasculature renale 24h dopo ischemia. I nostri risultati indicano che Minociclina attenua il difetto renale permeabilit&agrave; microvascolare seguendo l&#39;IRI. Questo effetto &egrave; spazialmente distinto dall&#39;effetto della minociclina sull&#39;accumulo dei leucociti e possa essere correlato all&#39;attivit&agrave; diminuita di MMP sull&#39;integrit&agrave; della matrice perivascolare.

Minociclina riduce perdite renali Microvascolari in un modello del ratto di lesione ischemica renale.

Tetraciclinas exhiben importantes propiedades antiinflamatorias, inhiben metaloproteinasas de matriz (MMPs) y tienen un efecto protectoras en modelos de isquemia reperfusi&oacute;n (IRI). Cascadas inflamatorias y activaci&oacute;n de MMP se han demostrado para modular la permeabilidad microvascular. Porque el aumento de la permeabilidad microvascular ocurre durante el IRI en una variedad de sistemas de &oacute;rganos como el ri&ntilde;&oacute;n, presume la minociclina, una tetraciclina semisint&eacute;tica, disminuir&iacute;a la fuga microvascular durante IRI renal. Para probar esta hip&oacute;tesis, utilizamos microscopia intravital de 2 fotones para examinar la salida de dextranos fluorescentes de la vasculatura en un modelo de roedor de IRI. Minociclina redujo significativamente el alcance de la fuga de dextrano (500 kDa) de la microvasculatura renal 24 h despu&eacute;s de la isquemia. Aunque minociclina disminuye la acumulaci&oacute;n de leucocitos en el ri&ntilde;&oacute;n tras isquemia, &aacute;reas de acumulaci&oacute;n de leucocitos no se correlacion&oacute; con las &aacute;reas de la permeabilidad microvascular en cualquiera de los animales pretratados de soluci&oacute;n salina o minociclina. Minociclina disminuy&oacute; el aumento perivascular MMP-2 y MMP-9, as&iacute; como el aumento en la actividad de la MMP-2 24 h despu&eacute;s de isquemia. ABT-518, un inhibidor espec&iacute;fico de MMP-2 y MMP-9, tambi&eacute;n significativamente reducido la magnitud de la fuga de dextrano (500 kDa) de la microvasculatura renal 24 h tras la isquemia. Nuestros resultados indican que la minociclina mitiga el defecto de la permeabilidad microvascular renal despu&eacute;s de IRI. Este efecto es espacial distinta del efecto de la minociclina en la acumulaci&oacute;n de leucocitos y puede estar relacionada con la actividad disminuida de MMP en la integridad de la matriz perivascular.

Minociclina reduce la fuga microvascular renal en un modelo de rata de lesi&oacute;n renal isqu&eacute;mica.

Functional and structural abnormalities in the renal microvasculature are important processes contributing to the pathophysiology of ischemic acute kidney injury (AKI). In this study, we examine the contribution of endothelial cell loss via apoptosis on microvascular permeability and rarefaction in a mouse model of ischemic AKI. Three-dimensional reconstructions of microvascular networks obtained 24 h following acute ischemic injury demonstrate an intact endothelial monolayer in areas of increased microvascular permeability. A 45% decrease in microvascular density was observed 4 wk after acute ischemic injury. Examination of microvascular endothelial cells following acute ischemic injury did not reveal evidence of positive terminal deoxynucleotidyl transferase dUTP-mediated nick-end labeling staining at 1, 2, 8, and 16 days following ischemia; however, activation of caspase-3 was evident in endothelial cells following acute ischemic injury. Examination of angiopoietin (Ang) protein expression in the kidney 24 h after ischemic injury revealed an eightfold increase in Ang-1 but no significant change in Ang-2. No significant difference in the expression of vascular endothelial growth factor or Ang-2 was observed 4 wk after ischemic injury, although an almost twofold elevation in Ang-1 was observed. An increase in angiostatic breakdown products of collagen IV was observed at both 24 h and 4 wk after ischemic injury. Taken together, these findings indicate that the loss of endothelial cells following ischemic injury is not a major contributor to altered microvascular permeability, although renal microvascular endothelial cells are vulnerable to the initiation of apoptotic mechanisms following ischemic injury that can ultimately impact microvascular density.

Acute and chronic microvascular alterations in a mouse model of ischemic acute kidney injury.

Ischemia-reperfusion injury (IRI) is a common cause of acute kidney injury (AKI) and is characterized by widespread tubular and microvascular damage. The tumor suppressor p53 is upregulated after IRI and contributes to renal injury in part by promoting apoptosis. Acute, short-term inhibition of p53 with pifithrin-alpha conveys significant protection after IRI. The hypoxia-inducible factor-1 (HIF-1) pathway is also activated after IRI and has opposing effects to those promoted by p53. The balance between the HIF-1 and p53 responses can determine the outcome of IRI. In this manuscript, we investigate whether p53 regulates the HIF-1 pathway in a rodent model of IRI. HIF-1alpha is principally expressed in the collecting tubules (CT) and thick ascending limbs (TAL) under physiological conditions. However, inhibition of p53 with pifithrin-alpha increases the faint expression of HIF-1alpha in proximal tubules (PT) under physiological conditions. Twenty-four hours after IRI, HIF-1alpha expression is decreased in both CT and TAL. HIF-1alpha expression in the PT is not significantly altered after IRI. Acute inhibition of p53 significantly increases HIF-1alpha expression in the PT after IRI. Additionally, pifithrin-alpha prevents the IRI-induced decrease in HIF-1alpha in the CT and TAL. Parallel changes are observed in the HIF-1alpha transcriptive target, carbonic anhydrase-9. Finally, inhibition of p53 prevents the dramatic changes in Von Hippel-Lindau protein morphology and expression after IRI. We conclude that activation of p53 after IRI mitigates the concomitant activation of the protective HIF-1 pathway. Modulating the interactions between the p53 and HIF-1 pathway can provide novel options in the treatment of AKI.

p53 regulates renal expression of HIF-1{alpha} and pVHL under physiological conditions and after ischemia-reperfusion injury.

Acute kidney injury induces the loss of renal microvessels, but the fate of endothelial cells and the mechanism of potential vascular endothelial growth factor (VEGF)-mediated protection is unknown. Cumulative cell proliferation was analyzed in the kidney of Sprague-Dawley rats following ischemia-reperfusion (I/R) injury by repetitive administration of BrdU (twice daily) and colocalization in endothelial cells with CD31 or cablin. Proliferating endothelial cells were undetectable for up to 2 days following I/R and accounted for only âˆ¼1% of BrdU-positive cells after 7 days. VEGF-121 preserved vascular loss following I/R but did not affect proliferation of endothelial, perivascular cells or tubular cells. Endothelial mesenchymal transition states were identified by localizing endothelial markers (CD31, cablin, or infused tomato lectin) with the fibroblast marker S100A4. Such structures were prominent within 6 h and sustained for at least 7 days following I/R. A Tie-2-cre transgenic crossed with a yellow fluorescent protein (YFP) reporter mouse was used to trace the fate of endothelial cells and demonstrated interstititial expansion of YFP-positive cells colocalizing with S100A4 and smooth muscle actin following I/R. The interstitial expansion of YFP cells was attenuated by VEGF-121. Multiphoton imaging of transgenic mice revealed the alteration of YFP-positive vascular cells associated with blood vessels characterized by limited perfusion in vivo. Taken together, these data indicate that vascular dropout post-AKI results from endothelial phenotypic transition combined with an impaired regenerative capacity, which may contribute to progressive chronic kidney disease.

Impaired endothelial proliferation and mesenchymal transition contribute to vascular rarefaction following acute kidney injury.

Insuffisance r&eacute;nale aigu&euml; provoque la perte des microvaisseaux r&eacute;nales, mais le sort des cellules endoth&eacute;liales et le m&eacute;canisme du potentiel facteur de croissance endoth&eacute;lial vasculaire (VEGF)-protection de m&eacute;diation est inconnue. Prolif&eacute;ration cellulaire cumulative a &eacute;t&eacute; analys&eacute;e dans les reins des rats Sprague-Dawley apr&egrave;s isch&eacute;mie-reperfusion (I / R) blessures par l&#39;administration r&eacute;p&eacute;t&eacute;e de BrdU (deux fois par jour) et de colocalisation dans les cellules endoth&eacute;liales avec CD31 ou cablin. Prolif&eacute;ration de cellules endoth&eacute;liales n&#39;&eacute;taient pas d&eacute;tectables jusqu&#39;&agrave; 2 jours apr&egrave;s j&#39;ai / R et repr&eacute;sentaient seulement &sim;1 % de cellules BrdU positives apr&egrave;s 7 jours. VEGF-121 pr&eacute;serv&eacute; vasculaire perte suite &agrave; je / R, mais n&#39;a pas incidence sur la prolif&eacute;ration des cellules endoth&eacute;liales, de p&eacute;rivasculaire ou cellules tubulaires. Les &Eacute;tats de transition m&eacute;senchymateuses endoth&eacute;liales ont &eacute;t&eacute; identifi&eacute;s en localisant les marqueurs endoth&eacute;liales (CD31, cablin ou infus&eacute; lectine tomate) avec le marqueur de fibroblastes S100A4. Ces structures ont &eacute;t&eacute; importants dans les 6 h et soutenue pendant au moins 7 jours apr&egrave;s j&#39;ai / r. Une cravate-2-cre transg&eacute;nique crois&eacute; avec un jaune fluorescent protein (YFP) journaliste souris a &eacute;t&eacute; utilis&eacute;e pour tracer le destin des cellules endoth&eacute;liales et d&eacute;montr&eacute; interstititial expansion des cellules positives YFP colocalizing avec l&#39;actine muscle lisse et de S100A4 apr&egrave;s j&#39;ai / r. L&#39;expansion interstitielle des cellules de la YFP a &eacute;t&eacute; att&eacute;nu&eacute;e par le VEGF-121. Imagerie multiphoton de souris transg&eacute;niques ont r&eacute;v&eacute;l&eacute; l&#39;alt&eacute;ration des cellules vasculaires YFP-positives associ&eacute;es aux vaisseaux sanguins caract&eacute;ris&eacute;es par perfusion limit&eacute;e in vivo. Ensemble, ces donn&eacute;es indiquent que d&#39;abandon vasculaires post-AKI r&eacute;sulte de transition ph&eacute;notypique endoth&eacute;liale, combin&eacute;e avec une capacit&eacute; de r&eacute;g&eacute;n&eacute;ration avec facult&eacute;s affaiblies, qui peut-&ecirc;tre contribuer &agrave; une n&eacute;phropathie chronique progressive.

Prolif&eacute;ration endoth&eacute;liale avec facult&eacute;s affaiblies et transition m&eacute;senchymateuse contribuent &agrave; la rar&eacute;faction vasculaire suite d&#39;insuffisance r&eacute;nale aigu&euml;.

Danno renale acuto induce la perdita di Talengectasia renale, ma il destino delle cellule endoteliali e il meccanismo di potenziale fattore di crescita endoteliale vascolare (VEGF)-protezione mediata &egrave; sconosciuto. Proliferazione cellulare cumulativo &egrave; stata analizzata nei reni di ratti Sprague-Dawley dopo ischemia-riperfusione (I / R) lesioni ripetitive amministrazione di BrdU (due volte al giorno) e presenza nelle cellule endoteliali CD31 o cablin. Proliferazione delle cellule endoteliali erano inosservabile fino a 2 giorni dopo I / R e rappresentavano solo &sim;1% delle cellule di BrdU-positivo dopo 7 giorni. VEGF-121 conservato vascolare perdita seguendo I / R, ma non influenzano la proliferazione delle cellule endoteliali, perivascolari o delle cellule tubulari. Stati di transizione mesenchimale endoteliale sono stati identificati localizzando marcatori endoteliali (CD31, cablin, o infuso lectina pomodoro) con il marcatore del fibroblasto S100A4. Tali strutture erano prominenti entro 6 h e sostenuta per almeno 7 giorni dopo I / r. Tie-2-cre transgenici attraversato con un giallo proteina fluorescente (YFP) reporter mouse &egrave; stato utilizzato per tracciare il destino delle cellule endoteliali e dimostrato interstititial espansione di cellule YFP-positive colocalizing con S100A4 e muscolo liscio actina seguendo I / r. L&#39;espansione interstiziale delle cellule YFP &egrave; stato attenuato da VEGF-121. Multiphoton imaging di topi transgenici hanno rivelato l&#39;alterazione delle cellule vascolari YFP-positivi associati con vasi sanguigni caratterizzati da limitata perfusione in vivo. Presi insieme, questi dati indicano che quello forcellino vascolare post-AKI risultati da endoteliali transizione fenotipica combinato con una ridotta capacit&agrave; rigenerativa, che possono contribuire alla malattia renale cronica progressiva.

Ridotta proliferazione endoteliale e transizione mesenchimale contribuire alla rarefazione vascolare dopo lesioni renali acute.

La lesi&oacute;n renal aguda induce la p&eacute;rdida de los microvasos renales, pero el destino de las c&eacute;lulas endoteliales y el mecanismo del factor de crecimiento endotelial vascular potencial (VEGF)-protecci&oacute;n mediada es desconocido. Proliferaci&oacute;n celular acumulativo se analiz&oacute; en el ri&ntilde;&oacute;n de ratas Sprague-Dawley despu&eacute;s de isquemia-reperfusi&oacute;n (I / R) lesiones repetitiva administraci&oacute;n de BrdU (dos veces al d&iacute;a) y colocalizaci&oacute;n en c&eacute;lulas endoteliales con CD31 o cablin. Proliferaci&oacute;n de c&eacute;lulas endoteliales eran imperceptibles hasta 2 d&iacute;as despu&eacute;s me / R y representaron s&oacute;lo &sim;1% de c&eacute;lulas BrdU-positivas despu&eacute;s de 7 d&iacute;as. VEGF-121 conservado vascular p&eacute;rdida despu&eacute;s de la I / R pero no afectan la proliferaci&oacute;n de c&eacute;lulas endoteliales, de perivascular o c&eacute;lulas tubulares. Estados de transici&oacute;n mesenquimales endotelial se identificaron al localizar marcadores endoteliales (CD31, cablin o infundido la lectina de tomate) con el marcador de fibroblastos S100A4. Estas estructuras fueron prominentes dentro de las 6 h y sostenido durante al menos 7 d&iacute;as despu&eacute;s me / r. Un empate-2-cre transg&eacute;nico se cruz&oacute; con un amarillo prote&iacute;na fluorescente (YFP) reportero rat&oacute;n fue utilizado para rastrear el destino de las c&eacute;lulas endoteliales y demostrado interstititial expansi&oacute;n de c&eacute;lulas YFP-positivas colocalizing con actina S100A4 y del m&uacute;sculo liso, despu&eacute;s me / r. La expansi&oacute;n intersticial de c&eacute;lulas YFP fue atenuada por VEGF-121. Proyecci&oacute;n de imagen multifot&oacute;n de ratones transg&eacute;nicos revel&oacute; la alteraci&oacute;n de las c&eacute;lulas vasculares YFP-positivos asociados con los vasos sangu&iacute;neos caracterizados por perfusi&oacute;n limitada in vivo. Tomados en conjunto, estos datos indican que abandono vascular post-AKI resulta de transici&oacute;n fenot&iacute;pica endotelial combinado con una deteriorada capacidad regenerativa, que puede contribuir a la enfermedad renal cr&oacute;nica progresiva.

Proliferaci&oacute;n endotelial deteriorada y mesenquimal transici&oacute;n contribuyen a vacuo vascular despu&eacute;s de la lesi&oacute;n renal aguda.

Microvascular rarefaction following an episode of acute kidney injury (AKI) is associated with renal hypoxia and progression toward chronic kidney disease. The mechanisms contributing to microvascular rarefaction are not well-understood, although disruption in local angioregulatory substances is thought to contribute. Matrix metalloproteinase (MMP)-9 is an endopeptidase important in modifying the extracellular matrix (ECM) and remodeling the vasculature. We examined the role of MMP-9 gene deletion on microvascular rarefaction in a rodent model of ischemic AKI. MMP-9-null mice and background control (FVB/NJ) mice were subjected to bilateral renal artery clamping for 20 min followed by reperfusion for 14, 28, or 56 days. Serum creatinine level in MMP-9-null mice 24 h after injury [1.4 (SD 0.8) mg/dl] was not significantly different from FVB/NJ mice [1.5 (SD 0.6) mg/dl]. Four weeks after ischemic injury, FVB/NJ mice demonstrated a 30-40% loss of microvascular density compared with sham-operated (SO) mice. In contrast, microvascular density was not significantly different in the MMP-9-null mice at this time following injury compared with SO mice. FVB/NJ mice had a 50% decrease in tissue vascular endothelial growth factor (VEGF) 2 wk after ischemic insult compared with SO mice. A significant difference in VEGF was not observed in MMP-9-null mice compared with SO mice. There was no significant difference in the liberation of angioinhibitory fragments from the ECM between MMP-9-null mice and FVB/NJ mice following ischemic injury. In conclusion, MMP-9 deletion stabilizes microvascular density following ischemic AKI in part by preserving tissue VEGF levels.

MMP-9 gene deletion mitigates microvascular loss in a model of ischemic acute kidney injury.

Inhibition of the tumor suppressor p53 diminishes tubular cell apoptosis and protects renal function in animal models of acute kidney injury (AKI). Therefore, targeting p53 has become an attractive therapeutic strategy in the approach to AKI. Although the acute protective effects of p53 inhibition in AKI have been examined, there is still relatively little known regarding the impact of acute p53 inhibition on the chronic sequelae of AKI. Consequently, we utilized the p53 inhibitor pifithrin-α to examine the long-term effects of p53 inhibition in a rodent model of ischemic AKI. Male Sprague-Dawley rats were subjected to bilateral renal artery clamping for 30 min followed by reperfusion for up to 8 wk. Pifithrin-α or vehicle control was administered at the time of surgery and then daily for 2 days [brief acute administration (BA)] or 7 days [prolonged acute administration (PA)]. Despite the acute protective effect of pifithrin-α in models of ischemic AKI, we found no protection in the microvascular rarefaction at 4 wk or development fibrosis at 8 wk with pifithrin-α administered on the BA schedule compared with vehicle control-treated animals. Furthermore, pifithrin-α administered on a PA schedule actually produced worse fibrosis compared with vehicle control animals after ischemic injury [21%/area (SD4.4) vs.16%/area (SD3.6)] as well as under sham conditions [2.6%/area (SD1.8) vs. 4.7%/area (SD1.3)]. The development of fibrosis with PA administration was independent of microvascular rarefaction. We identified enhanced extracellular matrix production, epithelial-to-mesenchymal transition, and amplified inflammatory responses as potential contributors to the augmented fibrosis observed with PA administration of pifithrin-α.

The p53 inhibitor pifithrin-α can stimulate fibrosis in a rat model of ischemic acute kidney injury.

In the rat, p53 promotes tubular apoptosis after ischemic AKI. Acute pharmacologic inhibition of p53 is protective in this setting, but chronic inhibition enhances fibrosis, demonstrating that the role of p53 in ischemic AKI is incompletely understood. Here, we investigated whether genetic absence of p53 is also protective in ischemic AKI. Surprisingly, p53-knockout mice (p53(-/-)) had worse kidney injury, compared with wild-type mice, and exhibited increased and prolonged infiltration of leukocytes after ischemia. Acute inhibition of p53 with pifithrin-α in wild-type mice mimicked the observations in p53(-/-) mice. Chimeric mice that lacked p53 in leukocytes sustained injury similar to p53(-/-) mice, suggesting an important role for leukocyte p53 in ischemic AKI. Compared with wild-type mice, a smaller proportion of macrophages in the kidneys of p53(-/-) and pifithrin-α-treated mice after ischemic injury were the anti-inflammatory M2 phenotype. Ischemic kidneys of p53(-/-) and pifithrin-α-treated mice also showed reduced expression of Kruppel-like factor-4. Finally, models of peritonitis in p53(-/-) and pifithrin-α-treated mice confirmed the anti-inflammatory role of p53 and its effect on the polarization of macrophage phenotype. In summary, in contrast to the rat, inflammation characterizes ischemic AKI in mice; leukocyte p53 is protective by reducing the extent and duration of this inflammation and by promoting the anti-inflammatory M2 macrophage phenotype.

p53 is renoprotective after ischemic kidney injury by reducing inflammation.

Ischemia-reperfusion injury (IRI) due to hypotension is a common cause of human acute kidney injury (AKI). Hypoxia-inducible transcription factors (HIFs) orchestrate a protective response in renal endothelial and epithelial cells in AKI models. As human mucin 1 (MUC1) is induced by hypoxia and enhances HIF-1 activity in cultured epithelial cells, we asked whether mouse mucin 1 (Muc1) regulates HIF-1 activity in kidney tissue during IRI. Whereas Muc1 was localized on the apical surface of the thick ascending limb, distal convoluted tubule, and collecting duct in the kidneys of sham-treated mice, Muc1 appeared in the cytoplasm and nucleus of all tubular epithelia during IRI. Muc1 was induced during IRI, and Muc1 transcripts and protein were also present in recovering proximal tubule cells. Kidney damage was worse and recovery was blocked during IRI in Muc1 knockout mice compared with congenic control mice. Muc1 knockout mice had reduced levels of HIF-1α, reduced or aberrant induction of HIF-1 target genes involved in the shift of glucose metabolism to glycolysis, and prolonged activation of AMP-activated protein kinase, indicating metabolic stress. Muc1 clearly plays a significant role in enhancing the HIF protective pathway during ischemic insult and recovery in kidney epithelia, providing a new target for developing therapies to treat AKI. Moreover, our data support a role specifically for HIF-1 in epithelial protection of the kidney during IRI as Muc1 is present only in tubule epithelial cells.

Muc1 is protective during kidney ischemia-reperfusion injury.

The hypoxia-inducible factor (HIF)-1 and β-catenin protective pathways represent the two most significant cellular responses that are activated in response to acute kidney injury. We previously reported that murine mucin (Muc)1 protects kidney function and morphology in a mouse model of ischemia-reperfusion injury (IRI) by stabilizing HIF-1α, enhancing HIF-1 downstream signaling, and thereby preventing metabolic stress (Pastor-Soler et al. Muc1 is protective during kidney ischemia-reperfusion injury. Am J Physiol Renal Physiol 308: F1452-F1462, 2015). We asked if Muc1 regulates the β-catenin protective pathway during IRI as 1) β-catenin nuclear targeting is MUC1 dependent in cultured human cells, 2) β-catenin is found in coimmunoprecipitates with human MUC1 in extracts of both cultured cells and tissues, and 3) MUC1 prevents β-catenin phosphorylation by glycogen synthase kinase (GSK)3β and thereby β-catenin degradation. Using the same mouse model of IRI, we found that levels of active GSK3β were significantly lower in kidneys of control mice compared with Muc1 knockout (KO) mice. Consequently, β-catenin was significantly upregulated at 24 and 72 h of recovery and appeared in the nuclear fraction at 72 h in control mouse kidneys. Both β-catenin induction and nuclear targeting were absent in Muc1 KO mice. We also found downstream induction of β-catenin prosurvival factors (activated Akt, survivin, transcription factor T cell factor 4 (TCF4), and its downstream target cyclin D1) and repression of proapoptotic factors (p53, active Bax, and cleaved caspase-3) in control mouse kidneys that were absent or aberrant in kidneys of Muc1 KO mice. Altogether, the data clearly indicate that Muc1 protection during acute kidney injury proceeds by enhancing both the HIF-1 and β-catenin protective pathways. 

Muc1 enhances the β-catenin protective pathway during ischemia-reperfusion injury.

The metabolic status of the kidney is a determinant of injury susceptibility and a measure of progression for many disease processes; however, noninvasive modalities to assess kidney metabolism are lacking. In this study, we employed positron emission tomography (PET) and intravital multiphoton microscopy (MPM) to assess cortical and proximal tubule glucose tracer uptake, respectively, following experimental perturbations of kidney metabolism. Applying dynamic image acquisition PET with 2-fluoro-2-deoxyglucose (F-FDG) and tracer kinetic modeling, we found that an intracellular compartment in the cortex of the kidney could be distinguished from the blood and urine compartments in animals. Given emerging literature that the tumor suppressor protein p53 is an important regulator of cellular metabolism, we demonstrated that PET imaging was able to discern a threefold increase in cortical F-FDG uptake following the pharmacological inhibition of p53 in animals. Intravital MPM with the fluorescent glucose analog 2-[-(7-nitrobenz-2-oxa-1,3-diazol-4-yl)amino]-2-deoxyglucose (2-NBDG) provided increased resolution and corroborated these findings at the level of the proximal tubule. Extending our observation of p53 inhibition on proximal tubule glucose tracer uptake, we demonstrated by intravital MPM that pharmacological inhibition of p53 diminishes mitochondrial potential difference. We provide additional evidence that inhibition of p53 alters key metabolic enzymes regulating glycolysis and increases intermediates of glycolysis. In summary, we provide evidence that PET is a valuable tool for examining kidney metabolism in preclinical and clinical studies, intravital MPM is a powerful adjunct to PET in preclinical studies of metabolism, and p53 inhibition alters basal kidney metabolism.

Novel application of complementary imaging techniques to examine in vivo glucose metabolism in the kidney.

The development of chronic kidney disease (CKD) following an episode of acute kidney injury (AKI) is an increasingly recognized clinical problem. Inhibition of toll-like receptor 4 (TLR4) protects renal function in animal models of AKI and has become a viable therapeutic strategy in AKI. However, the impact of TLR4 inhibition on the chronic sequelae of AKI is unknown. Consequently, we examined the chronic effects of TLR4 inhibition in a model of ischemic AKI. Mice with a TLR4-deletion on a C57BL/6 background and wild-type (WT) background control mice (C57BL/6) were subjected to bilateral renal artery clamping for 19 min and reperfusion for up to 6 weeks. Despite the acute protective effect of TLR4 inhibition on renal function (serum creatinine 1.6 ± 0.4 mg/dL TLR4-deletion vs. 2.8 ± 0.3 mg/dL·WT) and rates of tubular apoptosis following ischemic AKI, we found no difference in neutrophil or macrophage infiltration. Furthermore, we observed significant protection from microvascular rarefaction at six weeks following injury with TLR4-deletion, but this did not alter development of fibrosis. In conclusion, we validate the acute protective effect of TLR4 signal inhibition in AKI but demonstrate that this protective effect does not mitigate the sequential fibrogenic response in this model of ischemic AKI. 

Inhibition of Toll-Like Receptor 4 Signaling Mitigates Microvascular Loss but Not Fibrosis in a Model of Ischemic Acute Kidney Injury.

STAT3 is a transcriptional regulator that plays an important role in coordinating inflammation and immunity. In addition, there is a growing appreciation of the role STAT3 signaling plays in response to organ injury following diverse insults. Acute kidney injury (AKI) from ischemia-reperfusion injury is a common clinical entity with devastating consequences, and the recognition that endothelial alterations contribute to kidney dysfunction in this setting is of growing interest. Consequently, we used a mouse with a genetic deletion of  restricted to the endothelium to examine the role of STAT3 signaling in the pathophysiology of ischemic AKI. In a mouse model of ischemic AKI, the loss of endothelial STAT3 signaling significantly exacerbated kidney dysfunction, morphologic injury, and proximal tubular oxidative stress. The increased severity of ischemic AKI was associated with more robust endothelial-leukocyte adhesion and increased tissue accumulation of F4/80 macrophages. Moreover, important proximal tubular adaptive mechanisms to injury were diminished in association with decreased tissue mRNA levels of the epithelial cell survival cytokine IL-22. In aggregate, these findings suggest that the endothelial STAT3 signaling plays an important role in limiting kidney dysfunction in ischemic AKI and that selective pharmacologic activation of endothelial STAT3 signaling could serve as a potential therapeutic target.

Endothelial STAT3 Modulates Protective Mechanisms in a Mouse Ischemia-Reperfusion Model of Acute Kidney Injury.

Microvascular perfusion dynamics are vital to physiological function and are frequently dysregulated in injury and disease. Typically studies measure microvascular flow in a few selected vascular segments over limited time, failing to capture spatial and temporal variability. To quantify microvascular flow in a more complete and unbiased way we developed STAFF (Spatial Temporal Analysis of Fieldwise Flow), a macro for FIJI open-source image analysis software. Using high-speed microvascular flow movies, STAFF generates kymographs for every time interval for every vascular segment, calculates flow velocities from red blood cell shadow angles, and outputs the data as color-coded velocity map movies and spreadsheets. In untreated mice, analyses demonstrated profound variation even between adjacent sinusoids over seconds. In acetaminophen-treated mice we detected flow reduction localized to pericentral regions. STAFF is a powerful new tool capable of providing novel insights by enabling measurement of the complex spatiotemporal dynamics of microvascular flow.

Article	Year
Injury of the renal microvascular endothelium alters barrier function after ischemia. American journal of physiology. Renal physiology\| PubMed ID: 12684225	2003
Minocycline reduces renal microvascular leakage in a rat model of ischemic renal injury. American journal of physiology. Renal physiology\| PubMed ID: 15353401	2005
Acute and chronic microvascular alterations in a mouse model of ischemic acute kidney injury. American journal of physiology. Renal physiology\| PubMed ID: 17626153	2007
p53 regulates renal expression of HIF-1{alpha} and pVHL under physiological conditions and after ischemia-reperfusion injury. American journal of physiology. Renal physiology\| PubMed ID: 18815219	2008
Impaired endothelial proliferation and mesenchymal transition contribute to vascular rarefaction following acute kidney injury. American journal of physiology. Renal physiology\| PubMed ID: 21123492	2011
MMP-9 gene deletion mitigates microvascular loss in a model of ischemic acute kidney injury. American journal of physiology. Renal physiology\| PubMed ID: 21454251	2011
The p53 inhibitor pifithrin-α can stimulate fibrosis in a rat model of ischemic acute kidney injury. American journal of physiology. Renal physiology\| PubMed ID: 22049400	2012
p53 is renoprotective after ischemic kidney injury by reducing inflammation. Journal of the American Society of Nephrology : JASN\| PubMed ID: 23222126	2013
Muc1 is protective during kidney ischemia-reperfusion injury. American journal of physiology. Renal physiology\| PubMed ID: 25925251	2015
Muc1 enhances the β-catenin protective pathway during ischemia-reperfusion injury. American journal of physiology. Renal physiology\| PubMed ID: 26739894	2016
Novel application of complementary imaging techniques to examine in vivo glucose metabolism in the kidney. American journal of physiology. Renal physiology\| PubMed ID: 26764206	2016
Inhibition of Toll-Like Receptor 4 Signaling Mitigates Microvascular Loss but Not Fibrosis in a Model of Ischemic Acute Kidney Injury. International journal of molecular sciences\| PubMed ID: 27136544	2016
Endothelial STAT3 Modulates Protective Mechanisms in a Mouse Ischemia-Reperfusion Model of Acute Kidney Injury. Journal of immunology research\| PubMed ID: 29181415	2017
A simple automated method for continuous fieldwise measurement of microvascular hemodynamics. Microvascular research\| PubMed ID: 30502365	2019

Henry Mang

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