assessment-sarcoplasmic-reticulum-calcium-reserve-intracellular

Assessment of Sarcoplasmic Reticulum Calcium Reserve and Intracellular Diastolic Calcium Removal in Isolated Ventricular Cardiomyocytes

Intracellular calcium recycling plays a critical role in regulation of systolic and diastolic function in cardiomyocytes. Cardiac sarcoplasmic reticulum ...

Zhejiang University School of Medicine

Mechanical stretch and oxidative stress have been shown to prolong action potential duration (APD) and produce early afterdepolarizations (EADs). Here, we developed a simulation model to study the role of stretch-activated channel (SAC) currents in triggering EADs in ventricular myocytes under oxidative stress. We adapted our coupling clamp circuit so that a model ionic current representing the actual SAC current was injected into ventricular myocytes and added as a real-time current. This current was calculated as I(SAC) = G(SAC) * (V(m) - E(SAC)), where G(SAC) is the stretch-activated conductance, V(m) is the membrane potential, and E(SAC) is the reversal potential. In rat ventricular myocytes, application of G(SAC) did not produce sustained automaticity or EADs, although turn-on of G(SAC) did produce some transient automaticity at high levels of G(SAC). Exposure of myocytes to 100 microM H(2)O(2) induced significant APD prolongation and increase in intracellular Ca(2+) load and transient, but no EAD or sustained automaticity was generated in the absence of G(SAC). However, the combination of G(SAC) and H(2)O(2) consistently produced EADs at lower levels of G(SAC) (2.6 +/- 0.4 nS, n = 14, P < 0.05). Pacing myocytes at a faster rate further prolonged APD and promoted the development of EADs. SAC activation plays an important role in facilitating the development of EADs in ventricular myocytes under acute oxidative stress. This mechanism may contribute to the increased propensity to lethal ventricular arrhythmias seen in cardiomyopathies, where the myocardium stretch and oxidative stress generally coexist.

Stretch-activated channel activation promotes early afterdepolarizations in rat ventricular myocytes under oxidative stress.

Recent studies have highlighted important roles of CaMKII in regulating Ca(2+) handling and excitation-contraction coupling. However, the cardiac effect of chronic CaMKII inhibition has not been well understood.

Alterations of L-type calcium current and cardiac function in CaMKII{delta} knockout mice.

Reduction of transient outward current (I(to)) and excessive activation of Ca(2+)/Calmodulin-dependent kinase II (CaMKII) are general features of ventricular myocytes in heart failure. We hypothesize that alterations of I(to) directly regulate CaMKII activation in cardiomyocytes.

Dynamic Kv4.3-CaMKII unit in heart: an intrinsic negative regulator for CaMKII activation.

Calmodulin-dependent protein kinase II (CaMKII) has been proposed to be a therapeutic target for heart failure (HF). However, the cardiac effect of chronic CaMKII inhibition in HF has not been well understood. We have tested alterations of Ca(2+) handling, excitation-contraction coupling, and in vivo β-adrenergic regulation in pressure-overload HF mice with CaMKIIδ knockout (KO). HF was produced in wild-type (WT) and KO mice 1 wk after severe thoracic aortic banding (sTAB) with a continuous left ventricle (LV) dilation and reduction of ejection fraction for up to 3 wk postbanding. Cardiac hypertrophy was similar between WT HF and KO HF mice. However, KO HF mice manifested exacerbation of diastolic function and reduction in cardiac reserve to β-adrenergic stimulation. Compared with WT HF, L-type calcium channel current (I(Ca)) density in KO HF LV was decreased without changes in I(Ca) activation and inactivation kinetics, whereas I(Ca) recovery from inactivation was accelerated and Ca(2+)-dependent I(Ca) facilitation, a positive staircase blunted in WT HF, was recovered. However, I(Ca) response to isoproterenol was reduced. KO HF myocytes manifested dramatic decrease in sarcoplasmic reticulum (SR) Ca(2+) leak and slowed cytostolic Ca(2+) concentration decline. Sarcomere shortening was increased, but relaxation was slowed. In addition, an increase in myofilament sensitivity to Ca(2+) and the slow skeletal muscle troponin I-to-cardiac troponin I ratio and interstitial fibrosis and a decrease in Na/Ca exchange function and myocyte apoptosis were observed in KO HF LV. CaMKIIδ KO cannot suppress severe pressure-overload-induced HF. Although cellular contractility is improved, it reduces in vivo cardiac reserve to β-adrenergic regulation and deteriorates diastolic function. Our findings challenge the strategy of CaMKII inhibition in HF.

CaMKII inhibition in heart failure, beneficial, harmful, or both.

&#x665A;&#x671F;&#x7684;&#x7CD6;&#x5316;&#x7EC8;&#x4EA7;&#x7269; &#xFF08;&#x5E74;&#x9F84;&#xFF09; &#xFF08;&#x536B;&#x751F;&#x5385;) &#x8840;&#x7BA1;&#x5E73;&#x6ED1;&#x808C;&#x7EC6;&#x80DE;&#x589E;&#x6B96;&#x4E2D;&#x53D1;&#x6325;&#x91CD;&#x8981;&#x4F5C;&#x7528;&#xFF0C;&#x5E76;&#x52A0;&#x901F;&#x7CD6;&#x5C3F;&#x75C5;&#x60A3;&#x8005;&#x52A8;&#x8109;&#x7CA5;&#x6837;&#x786C;&#x5316;&#x3002;&#x81EA;&#x566C;&#xFF0C;&#x7EF4;&#x6301;&#x751F;&#x547D;&#x7684;&#x8FC7;&#x7A0B;&#x4E2D;&#xFF0C;&#x662F;&#x52A8;&#x8109;&#x7CA5;&#x6837;&#x786C;&#x5316;&#x6591;&#x5757;&#x4E2D;&#x7684;&#x6C27;&#x5316;&#x7684;&#x8102;&#x8D28;&#x3001; &#x708E;&#x75C7;&#x548C;&#x4EE3;&#x8C22;&#x5E94;&#x529B;&#x6761;&#x4EF6;&#x523A;&#x6FC0;&#x4E86;&#x3002;&#x5728;&#x6211;&#x4EEC;&#x7684;&#x7814;&#x7A76;&#xFF0C;&#x6211;&#x4EEC;&#x5229;&#x7528; MTT &#x68C0;&#x6D4B;&#x65B9;&#x6CD5;&#x6765;&#x663E;&#x793A;&#x8BE5;&#x81EA;&#x566C;&#x53C2;&#x4E0E;&#x5E74;&#x9F84;&#x8BF1;&#x5BFC;&#x7684;&#x8840;&#x7BA1;&#x5E73;&#x6ED1;&#x808C;&#x7EC6;&#x80DE;&#x589E;&#x6B96;&#x589E;&#x6B96;&#x3002;&#x6B64;&#x5916;&#xFF0C;&#x6CBB;&#x7597;&#x4E0E;&#x5E74;&#x9F84; &#xFF08;100 &#x5FAE;&#x514B;/&#x6BEB;&#x5347;&#xFF09; &#x80FD;&#x8BF1;&#x53D1;&#x5927;&#x9F20;&#x7684;&#x65F6;&#x95F4;&#x548C;&#x5242;&#x91CF;&#x4F9D;&#x8D56;&#x6027;&#x65B9;&#x5F0F;&#x81EA;&#x566C;&#x4E3B;&#x52A8;&#x8109;&#x8840;&#x7BA1;&#x5E73;&#x6ED1;&#x808C;&#x7EC6;&#x80DE;&#x589E;&#x6B96;&#x3002;&#x8FD9;&#x4E9B;&#x7ED3;&#x679C;&#x88AB;&#x8FDB;&#x4E00;&#x6B65;&#x8BC1;&#x5B9E;&#x7535;&#x955C;&#x53CA;&#x514D;&#x75AB;&#x8367;&#x5149;&#x6210;&#x50CF;&#x3002;&#x6CBB;&#x7597;&#x4E0E;&#x5E74;&#x9F84;&#x6FC0;&#x6D3B; ERK&#x3001; JNK &#x548C; p38/MAPK&#xFF0C;&#x4F46;&#x6291;&#x5236; Akt&#x3002;&#x9884;&#x5904;&#x7406;&#x4E0E; ERK &#x7684;&#x6291;&#x5236;&#x5242;&#x548C; Akt &#x6D3B;&#x5316;&#x5242;&#x6291;&#x5236;&#x5E74;&#x9F84;&#x8BF1;&#x5BFC;&#x7684;&#x81EA;&#x566C;&#xFF0C;&#x8868;&#x660E;&#x5E74;&#x9F84;&#x8BF1;&#x4F7F;&#x536B;&#x751F;&#x5385;&#x901A;&#x8FC7; ERK &#x548C; Akt &#x4FE1;&#x53F7;&#x901A;&#x8DEF;&#x4E2D;&#x7684;&#x81EA;&#x566C;&#x3002;&#x6B64;&#x5916;&#xFF0C;&#x6124;&#x6012;&#x7684; RNA &#x5E72;&#x6270;&#x51CF;&#x5C11;&#x81EA;&#x566C;&#xFF0C;&#x6307;&#x793A;&#x5230;&#x6124;&#x6012;&#x5E74;&#x9F84;&#x8BF1;&#x5BFC;&#x7684;&#x81EA;&#x566C;&#x8FC7;&#x7A0B;&#x4E2D;&#x7684;&#x5173;&#x952E;&#x3002;&#x56E0;&#x6B64;&#xFF0C;&#x5E74;&#x9F84;&#x8BF1;&#x5BFC;&#x7684;&#x81EA;&#x566C;&#x6709;&#x52A9;&#x4E8E;&#x5E74;&#x9F84;&#x5F15;&#x8D77;&#x7684;&#x589E;&#x6B96;&#xFF0C;&#x8840;&#x7BA1;&#x5E73;&#x6ED1;&#x808C;&#x7EC6;&#x80DE;&#x589E;&#x6B96;&#xFF0C;&#x4E0E;&#x76F8;&#x5173;&#x7684;&#x7CD6;&#x5C3F;&#x75C5;&#x60A3;&#x8005;&#x52A8;&#x8109;&#x7CA5;&#x6837;&#x786C;&#x5316;&#x7684;&#x8FC7;&#x7A0B;&#x3002;

ERK &#x548C; Akt &#x4FE1;&#x53F7;&#x901A;&#x8DEF;&#x53C2;&#x4E0E;&#x5927;&#x9F20;&#x8840;&#x7BA1;&#x5E73;&#x6ED1;&#x808C;&#x7EC6;&#x80DE;&#x665A;&#x671F;&#x7CD6;&#x57FA;&#x5316;&#x7EC8;&#x4EA7;&#x7269;&#x8BF1;&#x5BFC;&#x81EA;&#x566C;&#x3002;

Advanced glycation end products (AGEs) play an important role in the proliferation of vascular smooth muscle cells (VSMCs) and accelerate atherosclerosis in diabetic patients. Autophagy, a life-sustaining process, is stimulated in atherosclerotic plaques by oxidized lipids, inflammation and metabolic stress conditions. In our studies, we utilized MTT assays to show that autophagy is involved in AGE-induced proliferation of VSMCs. Furthermore, treatment with AGEs (100Â Âµg/ml) could induce autophagy in a time- and dose-dependent manner in rat aortic VSMCs. These results were further substantiated by electron microscopy and immunofluorescence imaging. Treatment with AGEs activated ERK, JNK and p38/MAPK, but inhibited Akt. Pretreatment with an ERK inhibitor and an Akt activator inhibited AGE-induced autophagy, demonstrating that AGEs induce autophagy in VSMCs through the ERK and Akt signaling pathways. In addition, RNA interference of RAGE decreased autophagy, indicating that RAGE is pivotal in the process of AGE-induced autophagy. Therefore, AGE-induced autophagy contributes to the process of AGE-induced proliferation of VSMCs, which is related to atherosclerosis in diabetes.

ERK and Akt signaling pathways are involved in advanced glycation end product-induced autophagy in rat vascular smooth muscle cells.

Produits de glycation avanc&eacute;e (Age) jouent un r&ocirc;le important dans la prolif&eacute;ration des cellules de muscle lisse vasculaire (CMLV) et acc&eacute;l&eacute;rer l&#39;ath&eacute;roscl&eacute;rose chez les patients diab&eacute;tiques. Autophagie, un processus de maintien de la vie, est stimul&eacute;e dans les plaques d&#39;ath&eacute;roscl&eacute;rose par lipides oxyd&eacute;s, l&#39;inflammation et des conditions de stress m&eacute;tabolique. Dans nos &eacute;tudes, nous avons utilis&eacute; des dosages MTT pour montrer que l&#39;autophagie est impliqu&eacute; dans la prolif&eacute;ration induite par l&#39;&acirc;ge des CMLV. En outre, le traitement par &acirc;ges (100 &micro;g/ml) pouvait induire l&#39;autophagie de mani&egrave;re et dose-d&eacute;pendante du temps chez le rat CMLV aortiques. Ces r&eacute;sultats ont &eacute;t&eacute; &eacute;tay&eacute;es par microscopie et imagerie de l&#39;immunofluorescence. Traitement avec des &acirc;ges activ&eacute; ERK, JNK et p38/MAPK, mais inhibe l&#39;Akt. Un pr&eacute;traitement avec un inhibiteur ERK et un activateur de Akt inhib&eacute;e autophagie induite par l&#39;&acirc;ge, ce qui d&eacute;montre que les &acirc;ges induisent autophagie dans les CMLV ERK et Akt voies de signalisation. En outre, l&#39;interf&eacute;rence ARN de RAGE diminu&eacute; autophagie, indiquant que la RAGE est essentielle dans le processus d&#39;autophagie induite par l&#39;&acirc;ge. Par cons&eacute;quent, autophagie induite par l&#39;&acirc;ge contribue au processus de prolif&eacute;ration induite par l&#39;&acirc;ge des CMLV, qui est li&eacute;e &agrave; l&#39;ath&eacute;roscl&eacute;rose chez les diab&eacute;tiques.

ERK et voies de signalisation Akt sont impliqu&eacute;s dans l&#39;autophagie induite par le produit final de glycation avanc&eacute;e dans les cellules musculaires lisses vasculaires de rats.

Erweiterte Glycation Endprodukte (Alter) eine wichtige Rolle in der Verbreitung von vaskul&auml;ren glatten Muskelzellen (VSMCs) und beschleunigen Arteriosklerose bei diabetischen Patienten. Autophagy, eine lebenserhaltende Prozess wird in atherosklerotischen Plaques durch oxidierte Lipide, Entz&uuml;ndung und metabolische Belastung stimuliert. In unseren Studien genutzt wir MTT-Assays, um anzuzeigen, dass diese Autophagy in alt-induzierte Proliferation von VSMCs beteiligt ist. Dar&uuml;ber hinaus Behandlung mit Alter (100 &micro;g/ml) konnte Autophagy in Zeit und dosisabh&auml;ngige Weise Ratte induzieren aortalen VSMCs. Diese Ergebnisse wurden durch Elektronenmikroskopie und Immunfluoreszenz-Bildgebung weiter untermauert. Behandlung mit Alter aktiviert ERK, JNK und p38/MAPK, aber gehemmt Akt. Vorbehandlung mit einem ERK-Hemmer und ein Akt-Aktivator gehemmt Alter induziert Autophagy, demonstrieren, dass AGEs Autophagy in VSMCs durch die ERK und Akt Signalisierung Bahnen bewegen. Dar&uuml;ber hinaus verringert RNA-Interferenz des ZORNS Autophagy, zentrale dabei induziert durch Alter Autophagy RAGE hinweist. Alter-induzierte Autophagy tr&auml;gt, zum Prozess der Alter-induzierte Proliferation von VSMCs, die zur Atherosklerose bei Diabetes zusammenh&auml;ngt.

ERK und Akt-Signalwege sind erweiterte Glycation Endprodukt-induzierte Autophagy in Ratte vaskul&auml;ren glatten Muskelzellen beteiligt.

Prodotti finali di glicazione avanzata (AGEs) gioca un ruolo importante nella proliferazione delle cellule muscolari lisce vascolari (VSMCs) e accelerare l&#39;aterosclerosi in pazienti diabetici. Autophagy, un processo di sostegno vitale, &egrave; stimolato a placche aterosclerotiche di lipidi ossidati, infiammazione e condizioni di stress metabolico. Nei nostri studi, abbiamo utilizzato i dosaggi MTT per mostrare che autophagy &egrave; coinvolto nella proliferazione indotta da et&agrave; di VSMCs. Inoltre, il trattamento con Evo (100 &micro; g/ml) potrebbe indurre autophagy in maniera tempo - e dose-dipendente nel ratto VSMCs aortica. Questi risultati sono stati ulteriormente suffragati da imaging di immunofluorescenza e microscopia elettronica. Trattamento con Evo attivata ERK, JNK e p38/MAPK, ma inibito Akt. Pretrattamento con un inibitore ERK e un attivatore di Akt inibito autophagy et&agrave;-indotta, dimostrando che l&#39;et&agrave; indurre autophagy in VSMCs attraverso la ERK e Akt signaling pathways. Inoltre, interferenza del RNA di rabbia &egrave; diminuita autophagy, indicando che la rabbia &egrave; cruciale nel processo di et&agrave;-indotta autophagy. Pertanto, autophagy indotta da et&agrave; contribuisce al processo di proliferazione indotta da et&agrave; di VSMCs, che &egrave; legata all&#39;aterosclerosi nel diabete.

ERK e Akt signaling pathways sono coinvolti in glicazione avanzata autophagy prodotto finale-indotta in cellule muscolari lisce vascolari del ratto.

&#x30B0;&#x30EA;&#x30B1;&#x30FC;&#x30C8;&#x6700;&#x7D42;&#x7523;&#x7269; &#xFF08;&#x4E2D;&#x4E16;&#xFF09; &#x8840;&#x7BA1;&#x5E73;&#x6ED1;&#x7B4B;&#x7D30;&#x80DE; (VSMCs) &#x306E;&#x5897;&#x6B96;&#x306B;&#x91CD;&#x8981;&#x306A;&#x5F79;&#x5272;&#x3092;&#x679C;&#x305F;&#x3059;&#x3057;&#x3001;&#x7CD6;&#x5C3F;&#x75C5;&#x60A3;&#x8005;&#x306B;&#x304A;&#x3051;&#x308B;&#x52D5;&#x8108;&#x786C;&#x5316;&#x75C7;&#x3092;&#x52A0;&#x901F;&#x3057;&#x307E;&#x3059;&#x3002;&#x30AA;&#x30FC;&#x30C8;&#x30D5;&#x30A1;&#x30B8;&#x30FC;&#x3001;&#x751F;&#x547D;&#x7DAD;&#x6301;&#x306E;&#x30D7;&#x30ED;&#x30BB;&#x30B9;&#x3067;&#x306F;&#x3001;&#x52D5;&#x8108;&#x786C;&#x5316;&#x6027;&#x30D7;&#x30E9;&#x30FC;&#x30AF;&#x306E;&#x9178;&#x5316;&#x6CB9;&#x8102;&#x3001;&#x708E;&#x75C7;&#x304A;&#x3088;&#x3073;&#x4EE3;&#x8B1D;&#x30B9;&#x30C8;&#x30EC;&#x30B9;&#x6761;&#x4EF6;&#x306B;&#x3088;&#x3063;&#x3066;&#x523A;&#x6FC0;&#x3055;&#x308C;&#x307E;&#x3059;&#x3002;&#x79C1;&#x305F;&#x3061;&#x306E;&#x7814;&#x7A76;&#x3067;&#x306F;&#x3001;&#x30AA;&#x30FC;&#x30C8;&#x30D5;&#x30A1;&#x30B8;&#x30FC;&#x5E74;&#x9F62;&#x306B;&#x3088;&#x308B; VSMCs &#x306E;&#x5897;&#x6B96;&#x306B;&#x95A2;&#x4E0E;&#x3057;&#x3066;&#x3044;&#x308B;&#x3092;&#x8868;&#x793A;&#x3059;&#x308B;&#x306B;&#x306F;&#x3001;MTT &#x306E;&#x8A66;&#x91D1;&#x3092;&#x6D3B;&#x7528;&#x3057;&#x307E;&#x3059;&#x3002;&#x3055;&#x3089;&#x306B;, &#x5E74;&#x9F62;&#x306B;&#x3088;&#x308B;&#x6CBB;&#x7642; &#xFF08;100 &mu; g/&#x30DF;&#x30EA;&#x30EA;&#x30C3;&#x30C8;&#x30EB;&#xFF09; &#x6642;&#x9593;&#x3068;&#x7528;&#x91CF;&#x4F9D;&#x5B58;&#x7684;&#x306B;&#x30E9;&#x30C3;&#x30C8;&#x306B;&#x304A;&#x3051;&#x308B;&#x30AA;&#x30FC;&#x30C8;&#x30D5;&#x30A1;&#x30B8;&#x30FC;&#x3092;&#x8A98;&#x5C0E;&#x3059;&#x308B;&#x5927;&#x52D5;&#x8108;&#x306E; VSMCs&#x3002;&#x3053;&#x308C;&#x3089;&#x306E;&#x7D50;&#x679C;&#x306F;&#x3001;&#x3055;&#x3089;&#x306B;&#x96FB;&#x5B50;&#x9855;&#x5FAE;&#x93E1;&#x3068;&#x86CD;&#x5149;&#x30A4;&#x30E1;&#x30FC;&#x30B8;&#x30F3;&#x30B0;&#x306B;&#x3088;&#x308B;&#x7ACB;&#x8A3C;&#x3055;&#x308C;&#x307E;&#x3057;&#x305F;&#x3002;&#x5E74;&#x9F62;&#x306B;&#x3088;&#x308B;&#x6CBB;&#x7642; ERK&#x3001;JNK &#x3068; p38/MAPK &#x6D3B;&#x6027;&#x5316;&#x304C; Akt &#x3092;&#x6291;&#x5236;&#x3057;&#x307E;&#x3057;&#x305F;&#x3002;ERK &#x963B;&#x5BB3;&#x5264;&#x3068; Akt &#x6D3B;&#x6027;&#x5316;&#x524D;&#x51E6;&#x7406;&#x5E74;&#x9F62;&#x306B;&#x3088;&#x308B;&#x30AA;&#x30FC;&#x30C8;&#x30D5;&#x30A1;&#x30B8;&#x30FC;&#x306E;&#x5E74;&#x9F62; ERK &#x3068; Akt &#x30B7;&#x30B0;&#x30CA;&#x30EA;&#x30F3;&#x30B0;&#x7D4C;&#x8DEF;&#x3092;&#x901A;&#x3058;&#x3066; VSMCs &#x306B;&#x30AA;&#x30FC;&#x30C8;&#x30D5;&#x30A1;&#x30B8;&#x30FC;&#x3092;&#x8A98;&#x5C0E;&#x3059;&#x308B;&#x30C7;&#x30E2;&#x30F3;&#x30B9;&#x30C8;&#x30EC;&#x30FC;&#x30B7;&#x30E7;&#x30F3;&#x3092;&#x6291;&#x5236;&#x3057;&#x307E;&#x3057;&#x305F;&#x3002;&#x307E;&#x305F;&#x3001;RNA &#x5E72;&#x6E09;&#x306E;&#x6012;&#x308A;&#x306E;&#x6012;&#x308A;&#x304C;&#x5E74;&#x9F62;&#x306B;&#x3088;&#x308B;&#x30AA;&#x30FC;&#x30C8;&#x30D5;&#x30A1;&#x30B8;&#x30FC;&#x904E;&#x7A0B;&#x306B;&#x304A;&#x3044;&#x3066;&#x6975;&#x3081;&#x3066;&#x91CD;&#x8981;&#x3067;&#x3042;&#x308B;&#x3053;&#x3068;&#x3092;&#x793A;&#x3059;&#x30AA;&#x30FC;&#x30C8;&#x30D5;&#x30A1;&#x30B8;&#x30FC;&#x3092;&#x6E1B;&#x5C11;&#x3057;&#x307E;&#x3057;&#x305F;&#x3002;&#x3057;&#x305F;&#x304C;&#x3063;&#x3066;&#x3001;&#x5E74;&#x9F62;&#x306B;&#x3088;&#x308B;&#x30AA;&#x30FC;&#x30C8;&#x30D5;&#x30A1;&#x30B8;&#x30FC;&#x7CD6;&#x5C3F;&#x75C5;&#x306B;&#x304A;&#x3051;&#x308B;&#x52D5;&#x8108;&#x786C;&#x5316;&#x306B;&#x95A2;&#x9023;&#x3057;&#x3066;&#x3044;&#x308B; VSMCs &#x306E;&#x5E74;&#x9F62;&#x306B;&#x3088;&#x308B;&#x5897;&#x6B96;&#x306E;&#x904E;&#x7A0B;&#x306B;&#x8CA2;&#x732E;&#x3057;&#x307E;&#x3059;&#x3002;

ERK &#x3068; Akt &#x30B7;&#x30B0;&#x30CA;&#x30EA;&#x30F3;&#x30B0;&#x7D4C;&#x8DEF;&#x9AD8;&#x5EA6;&#x7CD6;&#x5316;&#x6700;&#x7D42;&#x88FD;&#x54C1;&#x8A98;&#x8D77;&#x30AA;&#x30FC;&#x30C8;&#x30D5;&#x30A1;&#x30B8;&#x30FC; &#x30E9;&#x30C3;&#x30C8;&#x8840;&#x7BA1;&#x5E73;&#x6ED1;&#x7B4B;&#x7D30;&#x80DE;&#x306B;&#x95A2;&#x4E0E;&#x3057;&#x3066;&#x3044;&#x307E;&#x3059;&#x3002;

&#xACE0;&#xAE09; glycation &#xC5D4;&#xB4DC; &#xC81C;&#xD488; (&#xB098;) &#xD608;&#xAD00; &#xD3C9;&#xD65C; &#xADFC; &#xC138;&#xD3EC; (VSMCs)&#xC758; &#xD655;&#xC0B0;&#xC5D0; &#xC911;&#xC694; &#xD55C; &#xC5ED;&#xD560;&#xC744; &#xD558; &#xACE0; &#xB2F9;&#xB1E8;&#xBCD1; &#xD658;&#xC790;&#xC5D0;&#xC11C; &#xB3D9;&#xB9E5; &#xACBD;&#xD654;&#xB97C; &#xAC00;&#xC18D;. Autophagy, &#xC0DD;&#xBA85; &#xC720;&#xC9C0; &#xD504;&#xB85C;&#xC138;&#xC2A4;&#xB294; &#xC0B0;&#xD654; &#xC9C0;&#xC9C8;, &#xC5FC;&#xC99D;, &#xB300;&#xC0AC; &#xC2A4;&#xD2B8;&#xB808;&#xC2A4; &#xC870;&#xAC74;&#xC5D0; &#xC758;&#xD574; &#xB3D9;&#xB9E5; &#xACBD; &#xD654;&#xC131; &#xD50C; &#xB77C;&#xD06C;&#xC5D0; &#xC790;&#xADF9; &#xC774;&#xB2E4;. &#xC6B0;&#xB9AC;&#xC758; &#xC5F0;&#xAD6C;&#xC5D0;&#xC11C; &#xC6B0;&#xB9AC;&#xB294; Vsmcs&#xC758; &#xD655;&#xC0B0; &#xC138; &#xC720;&#xB3C4; &#xADF8; autophagy &#xAD00;&#xB828; &#xD45C;&#xC2DC;&#xB97C; MTT &#xBD84;&#xC11D; &#xC2E4;&#xD5D8; &#xD65C;&#xC6A9;. &#xB610;&#xD55C;, &#xC5F0;&#xB839;&#xB300;&#xC640; &#xCE58;&#xB8CC; (100 &micro; g/ml)&#xC744; &#xC950;&#xC5D0; &#xC2DC;&#xAC04; &#xBC0F; &#xBCF5;&#xC6A9;&#xB7C9; &#xC758;&#xC874; &#xBC29;&#xC2DD;&#xC5D0;&#xC11C; autophagy &#xC720;&#xB3C4; &#xC218; &#xB300;&#xB3D9;&#xB9E5; VSMCs. &#xC774; &#xACB0;&#xACFC; &#xC804;&#xC790; &#xD604;&#xBBF8;&#xACBD; &#xBC0F; &#xBA74;&#xC5ED; &#xD615;&#xAD11; &#xC774;&#xBBF8;&#xC9D5;&#xC5D0; &#xC758;&#xD574; &#xC785;&#xC99D; &#xCD94;&#xAC00; &#xD588;&#xB2E4;. &#xCE58;&#xB8CC; &#xC5F0;&#xB839;&#xB300;&#xC640; ERK, JNK&#xC640; p38/MAPK &#xD65C;&#xC131;&#xD654; &#xD558;&#xC9C0;&#xB9CC; Akt&#xB97C; &#xC5B5;&#xC81C; &#xD569;&#xB2C8;&#xB2E4;. ERK &#xC5B5;&#xC81C;&#xC81C;&#xC640; Akt &#xD65C;&#xC131; &#xC81C; &#xC804;&#xCC98;&#xB9AC; &#xB098; ERK &#xBC0F; Akt &#xACBD;&#xB85C; &#xC2E0;&#xD638;&#xB97C; &#xD1B5;&#xD574; Vsmcs&#xC5D0;&#xC11C; autophagy &#xC720;&#xB3C4; &#xC2DC;&#xC5F0; &#xB098;&#xC774; &#xC720;&#xB3C4; autophagy &#xC800;&#xD574;. &#xB610;&#xD55C;, &#xBD84;&#xB178;&#xC758; RNA &#xAC04;&#xC12D; &#xAC10;&#xC18C; autophagy, &#xBD84;&#xB178; &#xB098;&#xC774; &#xC720;&#xB3C4; autophagy &#xACFC;&#xC815;&#xC5D0;&#xC11C; &#xC911;&#xCD94;&#xC801;&#xC778; &#xC784;&#xC744; &#xB098;&#xD0C0;&#xB0C5;&#xB2C8;&#xB2E4;. &#xB530;&#xB77C;&#xC11C; &#xB098;&#xC774; &#xC720;&#xB3C4; autophagy &#xB2F9;&#xB1E8;&#xBCD1;&#xC5D0;&#xC11C; &#xB3D9;&#xB9E5; &#xACBD;&#xD654;&#xC640; &#xAD00;&#xB828;&#xC774; &#xC788;&#xB294; VSMCs, &#xD655;&#xC0B0; &#xC138;&#xB97C; &#xC720;&#xBC1C; &#xD558;&#xB294; &#xACFC;&#xC815;&#xC5D0; &#xAE30;&#xC5EC; &#xD55C;&#xB2E4;.

ERK &#xBC0F; Akt &#xC2E0;&#xD638; &#xACBD;&#xB85C; &#xC950; &#xD608;&#xAD00; &#xD3C9;&#xD65C; &#xADFC; &#xC138;&#xD3EC;&#xC5D0;&#xC11C; &#xACE0;&#xAE09; glycation &#xC5D4;&#xB4DC; &#xC81C;&#xD488; &#xC720;&#xB3C4; autophagy &#xAD00;&#xB828;.

Productos finales de glicosilaci&oacute;n avanzada (edades) juegan un papel importante en la proliferaci&oacute;n de c&eacute;lulas musculares lisas vasculares (VSMCs) y acelera la aterosclerosis en pacientes diab&eacute;ticos. Autofagia, un proceso vital, es estimulada en placas ateroscler&oacute;ticas por l&iacute;pidos oxidados, inflamaci&oacute;n y condiciones de estr&eacute;s metab&oacute;lico. En nuestros estudios utilizamos MTT ensayos para mostrar que esa autofagia est&aacute; implicada en la proliferaci&oacute;n inducida por edad de VSMCs. Adem&aacute;s, el tratamiento con las edades (100 &micro;g/ml) podr&iacute;a inducir la autofagia de manera dependiente del tiempo y dosis en la rata VSMCs a&oacute;rticas. Estos resultados fueron m&aacute;s fundamentados por la proyecci&oacute;n de imagen de inmunofluorescencia y microscopia electr&oacute;nica. Tratamiento con edades hab&iacute;a activado ERK, JNK y p38/MAPK, pero inhibi&oacute; Akt. Tratamiento previo con un inhibidor ERK y un activador de Akt hab&iacute;a inhibida autofagia inducida por edad, demostrando que las edades inducen la autofagia en VSMCs a trav&eacute;s del ERK y v&iacute;as de se&ntilde;alizaci&oacute;n de Akt. Adem&aacute;s, ARN de interferencia de rabia disminuir autofagia, indicando que la rabia es fundamental en el proceso de autofagia inducida por edad. Por lo tanto, autofagia inducida por edad contribuye al proceso de proliferaci&oacute;n inducida por edad de VSMCs, que se relaciona con aterosclerosis en la diabetes.

ERK y v&iacute;as de se&ntilde;alizaci&oacute;n Akt participan glicaci&oacute;n avanzada inducida por producto final autofagia en las c&eacute;lulas de m&uacute;sculo liso vascular de rata.

CaMKII activation is proarrhythmic in heart failure where myocardium is stretched. However, the arrhythmogenic role of CaMKII in stretched ventricle has not been well understood.

Stretch current-induced abnormal impulses in CaMKIIδ knockout mouse ventricular myocytes.

Statins have beneficial pleiotropic effects beyond lipid lowering on the cardiovascular system. These cardio-protective effects are mediated through inhibition of the intracellular mevalonate pathway, by decreasing isoprenoid intermediate synthesis and the subsequent post-translational modification of small GTPases, such as Ras, Rho, and Rac. Impaired intracellular calcium handling is considered an important pathophysiologic mechanism responsible for cardiac dysfunction. Our study aimed at investigating the influence of mevalonate pathway, including its downstream small GTPases (Ras, RhoA, and Rac1) on anoxia-mediated alterations of calcium handling in H9c2 cardiomyocytes. Cultured H9c2 cardiomyocytes were exposed to acute anoxia after pretreatment with different drugs that specifically antagonize five key components in the mevalonate pathway, including 3-hydroxy-3-methylglutaryl-CoA reductase, farnesyl pyrophosphate synthase, Rho-kinase, Rac1 and Ras farnesyltransferase. Thereafter, we evaluated the effects of the mevalonate pathway on anoxia-induced cell death, expression of the sarcoplasmic reticulum calcium release channel (ryanodine receptor 2) and its regulator FK506-binding protein 12.6, as well as functional calcium release from intracellular calcium stores. Our experiments confirmed the role of prenylated proteins in regulating cardiomyocyte dysfunction, especially via RhoA- and Ras-related signaling pathways. Furthermore, our data demonstrated that inhibition of the mevalonate pathway could ameliorate anoxia-mediated calcium handling dysfunction with the up-regulated expression of FK506-binding protein 12.6 and consequently provided evidence for FK506-binding protein 12.6 as a "stabilizer" of ryanodine receptor 2.

Inhibition of the mevalonate pathway ameliorates anoxia-induced down-regulation of FKBP12.6 and intracellular calcium handling dysfunction in H9c2 cells.

Previous study showed inhibition of RhoA and Rho kinase (ROCK) activity with fasudil could alleviate diabetes-induced cardiac dysfunction partially due to improvement of myocardial fibrosis. However, the effect of fasudil on intracellular calcium cycling and actin remodeling, both of which are important to regulate excitation-contract coupling, is still not fully elucidated. In this study, a diabetic cardiomyopathy model was induced by a single intraperitoneal injection of streptozotocin (STZ) in male Sprague Dawley rats. Diabetic rats were treated with fasudil or placebo for 8 weeks. We found that long-term administration of fasudil, a specific Rho kinase inhibitor, significantly ameliorated diabetes-induced contractile dysfunction both at cellular and whole organ levels. Fasudil-treated rats displayed improved diastolic intracellular calcium ([Ca(2+)]i) removal and rescued expression of protein responsible for [Ca(2+)]i clearance. Furthermore, our study indicated that fasudil treatment normalized the phosphorylation of the PKCβ2/Akt pathway in the diabetic heart, which might be the underlying mechanism accounting for the protective effect of fasudil on [Ca(2+)]i clearance. In addition, compared to the diabetes group, fasudil also normalized the G/F-actin ratio by preventing cofilin phosphorylation and promoted F-actin organization, suggesting a beneficial effect on actin remodeling. These findings indicate the protective effect of fasudil against diabetes-induced cardiac dysfunction via modulation of Ca(2+) handling and actin remodeling. Overactivation of RhoA/ROCK plays a key role in the development of DCM. Inhibition of ROCK activity with fasudil improved [Ca(2+)]i removal in diabetic cardiomyocytes. Fasudil normalized the G/F-actin ratio and promoted F-actin organization. ROCK may be an excellent therapeutic target for the treatment of DCM.

The Rho kinase inhibitor, fasudil, ameliorates diabetes-induced cardiac dysfunction by improving calcium clearance and actin remodeling.

Erratum to: The Rho kinase inhibitor, fasudil, ameliorates diabetes-induced cardiac dysfunction by improving calcium clearance and actin remodeling.

We previously demonstrated that anoxia-mediated Ca(2+) handling dysfunction could be ameliorated through inhibition of mevalonate pathway via RhoA- and Ras-related mechanisms in H9c2 cells. In this study, we further explored whether inhibition of mevalonate pathway is associated with cardiac remodeling and dysfunction in ischemic cardiomyopathy, and discuss the possible role of Ras, Rac and RhoA in cardiac dysfunction.

Dongwu Lai

Department of Cardiology,
Sir Run Run Shaw Hospital,
Department of Cardiology, Sir Run Run Shaw Hospital

Zhejiang University School of Medicine

Assessment of Sarcoplasmic Reticulum Calcium Reserve and Intracellular Diastolic Calcium Removal in Isolated Ventricular Cardiomyocytes

Dongwu Lai

.css-o250i3{font-size:18px;font-family:Open Sans,sans-serif;line-height:21.6px;}Department of Cardiology,Sir Run Run Shaw Hospital,Department of Cardiology, Sir Run Run Shaw Hospital

Zhejiang University School of Medicine

Assessment of Sarcoplasmic Reticulum Calcium Reserve and Intracellular Diastolic Calcium Removal in Isolated Ventricular Cardiomyocytes

Department of Cardiology,
Sir Run Run Shaw Hospital,
Department of Cardiology, Sir Run Run Shaw Hospital