RESUMEN

Ischemic pre-conditioning has been shown to protect hearts against ischemia/reperfusion (I/R)-induced cardiac injury. However, it is not feasible in clinic. Many researchers have tried to introduce brief I/R in skeletal muscle to mimic cardiac ischemic pre-conditioning, called remote ischemia pre-conditioning (RIPC). Studies from our group and other groups have shown that RIPC induces the release of cytokines from skeletal muscle (myokines) for tissue protection. Myokines play a central role in repair, inflammatory, and immune responses after injury. Thus, the detailed protocol for RIPC might be useful for researchers to study mechanisms underlying RIPC-mediated tissue protection and crosstalk. Here, we describe a detailed RIPC protocol and show MG53 secretion after RIPC into the blood.

Asunto(s)

Precondicionamiento Isquémico , Daño por Reperfusión , Humanos , Precondicionamiento Isquémico/métodos , Daño por Reperfusión/prevención & control , Citocinas , Músculo Esquelético , Isquemia

RESUMEN

BACKGROUND: Ischemia preconditioning (IPC) ameliorates coronary no-reflow induced by ischemia/reperfusion (I/R) injury, and pericytes play an important role in microvascular function. However, it is unclear whether IPC exerts a protective effect on coronary microcirculation and regulates the pericytes. OBJECTIVE: The purpose of this study was to assess whether IPC improves coronary microvascular perfusion and reduces pericyte constriction after myocardial I/R injury. METHODS: Rats were randomly divided into three groups: the sham group, the I/R group, and the IPC + I/R group. The left anterior descending artery (LAD) of rats in the I/R group were ligated for 45 min, and the rats in the IPC + I/R group received 4 episodes of 6min occlusion followed by 6min reperfusion before the LAD was ligated. After 24 h of reperfusion, the area of no-reflow, and area at risk were evaluated with thioflavin-S and Evens blue staining, and infarct size with triphenyl tetrazolium chloride staining, respectively. Besides, fluorescent microspheres were perfused to enable visualization of the non-obstructed coronary vessels. Cardiac pericytes and microvascular were observed by immunofluorescence, and the diameter of microvascular at the site of the pericyte somata was analyzed. RESULTS: The infarct size, and area of no-reflow in the IPC + I/R group were significantly reduced compared with the I/R group (infarct size, 33.5% ± 11.9% vs. 49.2% ± 9.4%, p = 0.021；no-reflow, 12.7% ± 5.2% vs. 26.6% ± 5.0%, p < 0.001). IPC improved microvascular perfusion and reduced the percentage of the blocked coronary capillary. Moreover, we found that cardiac pericytes were widely distributed around the microvascular in various regions of the heart, and expressed the contractile protein α-smooth muscle actin. The microvascular lumen diameter at pericyte somata was reduced after I/R (4.3 ± 1.0 µm vs. 6.5 ± 1.2 µm, p < 0.001), which was relieved in IPC + I/R group compared with the I/R group (5.2 ± 1.0 µm vs. 4.3 ± 1.0 µm, p < 0.001). Besides, IPC could reduce the proportion of apoptotic pericytes compared to the I/R group (22.1% ± 8.4% vs. 38.5% ± 7.5%, p < 0.001). CONCLUSION: IPC reduced no-reflow and inhibited the contraction of microvascular pericytes induced by cardiac I/R injury, suggesting that IPC might play a protective role by regulating the pericyte function.

Asunto(s)

Infarto del Miocardio , Daño por Reperfusión Miocárdica , Animales , Vasos Coronarios , Isquemia , Daño por Reperfusión Miocárdica/metabolismo , Pericitos/metabolismo , Ratas

RESUMEN

Preconditioning is often used in medicine to protect organs from ischemic damage and in athletes to enhance the performances. We tested whether low-dose ammonium preconditioning (AMP) could have a beneficial effect on physical exercises (PE). We used Cardiopulmonary Exercise Testing (CPET) on a treadmill to investigate the effects of low-dose AMP on the physical exercise capacity of professional track and field athletes and tested twenty-five athletes. Because of the individual differences between athletes, we performed a preliminary treadmill test (Pre-test) and, according to the results, the athletes were randomly allocated into the AMP and control (placebo, PL) group based on the similarity of the total distance covered on a treadmill. In the AMP group, the covered distance increased (11.3 ± 3.6%, p < 0.02) compared to Pre-test. Similarly, AMP significantly increased O2 uptake volume-VO2 (4.6 ± 2.3%, p < 0.03) and pulmonary CO2 output-VCO2 (8.7 ± 2.8%, p < 0.01). Further, the basic blood parameters (pH, pO2, and lactate) shift was lower despite the greater physical exercise progress in the AMP group compared to Pre-test, whereas in the placebo group there were no differences between Pre-test and Load-test. Importantly, the AMP significantly increased red blood cell count (6.8 ± 2.0%, p < 0.01) and hemoglobin concentration (5.3 ± 1.9%, p < 0.01), which might explain the beneficial effects in physical exercise progress. For the first time, we showed that low-dose AMP had clear beneficial effects on submaximal PE.

RESUMEN

It has been shown that ischemia preconditioning (IPC) can attenuate the myocardial injury induced by ischemic and reperfusion. But it was rarely used in clinic due to its inoperability. Previous studies indicate that electroacupuncture (EA) pretreatment can mimic myocardial ischemia preconditioning (MIPC) to produce cardioprotective effect. The activated adenosine A 2 b receptor has been proven to be involved in mediating the cardioprotection of IPC. In the studies on acupuncture analgesia, it was reported that adenosine receptor was activated by acupuncture stimulation, and acupuncture pretreatment can affect the acti-vities of intracellular A 2 b receptor. Based on those mentioned above, it is highly likely that the A 2 b receptor may also participate in the cardioprotection produced by acupuncture pretreatment. In this paper, we comprehensively reviewed relevant studies regarding 1) the cardioprotective effect of IPC and its limitations, 2) the similar cardioprotection produced by both acupuncture pre-treatment and IPC, 3) the mechanism underlying myocardial ischemic injury and intracellular calcium regulation, 4) the acti-vation of adenosine receptors and effects of acupuncture, 5) the relationship between adenosine receptors and intracellular calcium ion, and 6) the effect of acupuncture on adenosine receptors, so as to provide a novel assumption that A 2 b receptor may be a key factor in mediating the cardioprotection of acupuncture pretreatment. Our future research will systematically explore the me-chanism of acupuncture pretreatment in protecting ischemic myocardium from myocardial cell adenosine A 2 b receptor and intracellular calcium signal transduction related factors.

Asunto(s)

Precondicionamiento Isquémico Miocárdico , Acupuntura , Adenosina , Calcio , Humanos , Infarto del Miocardio , Receptor de Adenosina A2B , Receptores Purinérgicos P1

RESUMEN

BACKGROUND: Ischemia preconditioning (IPC) remains the most powerful intervention of protection against myocardial ischemia/reperfusion injury (IRI), but diabetes can weaken or eliminate its cardioprotective effect and detailed mechanisms remain unclear. In this study, we aimed to explore whether changes of autophagy in the diabetic condition are attributable to the decreased cardioprotective effect of IPC. METHODS: Sixty diabetic male Sprague-Dawley rats were randomly divided into the control (C), IRI, rapamycin (R), wortmannin (W), rapamycin + IPC (R + IPC), and wortmannin + IPC (W + IPC) groups. The in vivo rat model of myocardial IRI was established by ligaturing and opening the left anterior descending coronary artery via the left thoracotomy. Durations of ischemia and reperfusion are 30 min and 120 min, respectively. Blood samples were taken at 120 min of reperfusion for measuring serum concentrations of troponin I (TnI) and creatine kinase isoenzyme MB (CK-MB) using the enzyme-linked immunosorbent assay. The infarct size was assessed by Evans blue and triphenyltetrazolium chloride staining. The expressions of LC3-II, beclin-1, phosphoinositide 3-kinase (PI3K), mammalian target of rapamycin (mTOR), and P-Akt/Akt ratio in the ischemic myocardium were assessed by Western blotting. RESULTS: Compared to the IRI group, infarct size (56.1% ± 6.1% vs. 75.4 ± 7.1%, P < 0.05), serum cTnI (0.61 ± 0.21 vs. 0.95 ± 0.26 ng/ml, P < 0.05), and CK-MB levels (6.70 ± 1.25 vs. 11.51 ± 2.35 ng/ml, P < 0.05) obviously decreased in the W + IPC group. Compared with the C group, myocardial expressions of LC3-II (0.46 ± 0.04 and 0.56 ± 0.04 vs. 0.36 ± 0.04, P < 0.05) and beclin-1 (0.34 ± 0.08 and 0.38 ± 0.07 vs. 0.24 ± 0.03, P < 0.05) evidently increased, and myocardial expressions of mTOR (0.26 ± 0.08 and 0.25 ± 0.07 vs. 0.38 ± 0.06, P < 0.05), PI3K (0.29 ± 0.04 and 0.30 ± 0.03 vs. 0.38 ± 0.02, P < 0.05), and P-Akt/Akt ratio (0.49 ± 0.10 and 0.48 ± 0.06 vs. 0.72 ± 0.07, P < 0.05) markedly decreased in the IRI and R groups, indicating an increased autophagy. Compared with the IRI group, myocardial expression of beclin-1 (0.26 ± 0.03 vs. 0.34 ± 0.08, P < 0.05) significantly decreased, and myocardial expressions of mTOR (0.36 ± 0.04 vs. 0.26 ± 0.08, P < 0.05), PI3K (0.37 ± 0.03 vs. 0.29 ± 0.04, P < 0.05), and P-Akt/Akt ratio (0.68 ± 0.05 vs. 0.49 ± 0.10, P < 0.05) increased obviously in the W + IPC group, indicating a decreased autophagy. CONCLUSIONS: Increased autophagy in the diabetic myocardium is attributable to decreased cardioprotection of IPC, and autophagy inhibited by activating the PI3K-Akt-mTOR signaling pathway can result in an improved protection of IPC against diabetic myocardial IRI.

Asunto(s)

Autofagia , Precondicionamiento Isquémico Miocárdico , Infarto del Miocardio , Daño por Reperfusión Miocárdica , Animales , Diabetes Mellitus Experimental , Masculino , Fosfatidilinositol 3-Quinasas , Conejos , Distribución Aleatoria , Ratas , Ratas Sprague-Dawley

RESUMEN

Background OBJECTIVE: The cerebral ischemia/reperfusion greatly influences brain metabolism. Remote ischemia preconditioning (RIPC) is reported to confer neuroprotective effects against cerebral ischemia in animal models and human. This study aims to investigate the metabolomic profiles of cerebrospinal fluid (CSF) in patients treated with repetitive lower limb RIPC and provides an insight into possible mechanism underlying RIPC-induced neuroprotection. METHOD: Fifty healthy patients undergoing minor surgery under spinal anesthesia were randomly allocated to 2 groups: control group (Group C, n = 25) and RIPC treatment group (Group T,n = 25). Repetitive limb RIPC were performed 3 sessions, consisting of three 5-min cycles per session from the day before surgery to the morning on the surgery day. The CSF samples were collected from 48 patients before intrathecal injection of local anesthetic. A proton nuclear magnetic resonance (1H NMR)-based metabonomics approach was used to obtain the CSF metabolic profiles of the samples (n = 24 each). The acquired data were processed with MestReNova and followed by statistical analysis with SIMCA-P. RESULTS: The model obtained with the orthogonal partial least-squares discriminant analysis (OPLS-DA) identified difference of metabolite profiles between two groups. The validation of the discriminant analysis showed that the accuracy of the OPLS-DA model was 81.3%. Sixteen metabolites including glucose, amino-acids and organic acids et al. were identified as the most influential CSF biomarkers for the discrimination between two groups, which are involved in pathways of energy metabolism and amino-acids metabolism. CONCLUSION: 1H NMR spectra combined with pattern recognition analysis offers a new and promising platform to investigate metabolic signatures in patients treated with RIPC. Our results suggest repetitive RIPC mainly changes energy metabolism and amino-acid metabolism in brain, which provides a potential mechanistic understanding of RIPC-induced tolerance to cerebral ischemia.

Asunto(s)

Isquemia Encefálica/líquido cefalorraquídeo , Precondicionamiento Isquémico , Extremidad Inferior/fisiopatología , Daño por Reperfusión/prevención & control , Adulto , Anciano , Encéfalo/metabolismo , Encéfalo/fisiopatología , Isquemia Encefálica/complicaciones , Femenino , Humanos , Precondicionamiento Isquémico/métodos , Extremidad Inferior/irrigación sanguínea , Imagen por Resonancia Magnética/métodos , Espectroscopía de Resonancia Magnética/métodos , Masculino , Persona de Mediana Edad , Fármacos Neuroprotectores/farmacología , Daño por Reperfusión/líquido cefalorraquídeo

RESUMEN

It has been shown that ischemia preconditioning (IPC) can attenuate the myocardial injury induced by ischemic and reperfusion. But it was rarely used in clinic due to its inoperability. Previous studies indicate that electroacupuncture (EA) pretreatment can mimic myocardial ischemia preconditioning (MIPC) to produce cardioprotective effect. The activated adenosine A 2 b receptor has been proven to be involved in mediating the cardioprotection of IPC. In the studies on acupuncture analgesia, it was reported that adenosine receptor was activated by acupuncture stimulation, and acupuncture pretreatment can affect the acti-vities of intracellular A 2 b receptor. Based on those mentioned above, it is highly likely that the A 2 b receptor may also participate in the cardioprotection produced by acupuncture pretreatment. In this paper, we comprehensively reviewed relevant studies regarding 1) the cardioprotective effect of IPC and its limitations, 2) the similar cardioprotection produced by both acupuncture pre-treatment and IPC, 3) the mechanism underlying myocardial ischemic injury and intracellular calcium regulation, 4) the acti-vation of adenosine receptors and effects of acupuncture, 5) the relationship between adenosine receptors and intracellular calcium ion, and 6) the effect of acupuncture on adenosine receptors, so as to provide a novel assumption that A 2 b receptor may be a key factor in mediating the cardioprotection of acupuncture pretreatment. Our future research will systematically explore the me-chanism of acupuncture pretreatment in protecting ischemic myocardium from myocardial cell adenosine A 2 b receptor and intracellular calcium signal transduction related factors.

RESUMEN

<p><b>Background</b>Ischemia preconditioning (IPC) remains the most powerful intervention of protection against myocardial ischemia/reperfusion injury (IRI), but diabetes can weaken or eliminate its cardioprotective effect and detailed mechanisms remain unclear. In this study, we aimed to explore whether changes of autophagy in the diabetic condition are attributable to the decreased cardioprotective effect of IPC.</p><p><b>Methods</b>Sixty diabetic male Sprague-Dawley rats were randomly divided into the control (C), IRI, rapamycin (R), wortmannin (W), rapamycin + IPC (R + IPC), and wortmannin + IPC (W + IPC) groups. The in vivo rat model of myocardial IRI was established by ligaturing and opening the left anterior descending coronary artery via the left thoracotomy. Durations of ischemia and reperfusion are 30 min and 120 min, respectively. Blood samples were taken at 120 min of reperfusion for measuring serum concentrations of troponin I (TnI) and creatine kinase isoenzyme MB (CK-MB) using the enzyme-linked immunosorbent assay. The infarct size was assessed by Evans blue and triphenyltetrazolium chloride staining. The expressions of LC3-II, beclin-1, phosphoinositide 3-kinase (PI3K), mammalian target of rapamycin (mTOR), and P-Akt/Akt ratio in the ischemic myocardium were assessed by Western blotting.</p><p><b>Results</b>Compared to the IRI group, infarct size (56.1% ± 6.1% vs. 75.4 ± 7.1%, P < 0.05), serum cTnI (0.61 ± 0.21 vs. 0.95 ± 0.26 ng/ml, P < 0.05), and CK-MB levels (6.70 ± 1.25 vs. 11.51 ± 2.35 ng/ml, P < 0.05) obviously decreased in the W + IPC group. Compared with the C group, myocardial expressions of LC3-II (0.46 ± 0.04 and 0.56 ± 0.04 vs. 0.36 ± 0.04, P < 0.05) and beclin-1 (0.34 ± 0.08 and 0.38 ± 0.07 vs. 0.24 ± 0.03, P < 0.05) evidently increased, and myocardial expressions of mTOR (0.26 ± 0.08 and 0.25 ± 0.07 vs. 0.38 ± 0.06, P < 0.05), PI3K (0.29 ± 0.04 and 0.30 ± 0.03 vs. 0.38 ± 0.02, P < 0.05), and P-Akt/Akt ratio (0.49 ± 0.10 and 0.48 ± 0.06 vs. 0.72 ± 0.07, P < 0.05) markedly decreased in the IRI and R groups, indicating an increased autophagy. Compared with the IRI group, myocardial expression of beclin-1 (0.26 ± 0.03 vs. 0.34 ± 0.08, P < 0.05) significantly decreased, and myocardial expressions of mTOR (0.36 ± 0.04 vs. 0.26 ± 0.08, P < 0.05), PI3K (0.37 ± 0.03 vs. 0.29 ± 0.04, P < 0.05), and P-Akt/Akt ratio (0.68 ± 0.05 vs. 0.49 ± 0.10, P < 0.05) increased obviously in the W + IPC group, indicating a decreased autophagy.</p><p><b>Conclusions</b>Increased autophagy in the diabetic myocardium is attributable to decreased cardioprotection of IPC, and autophagy inhibited by activating the PI3K-Akt-mTOR signaling pathway can result in an improved protection of IPC against diabetic myocardial IRI.</p>

RESUMEN

Objective To evaluate the effect of electroacupuncture ( EA) preconditioning on hipp-ocampal I-kappa B-α ( IκB-α)∕nuclear factor κB ( NF-κB)∕intercellular adhesion molecule-1 ( ICAM-1) signaling pathway during cerebral ischemia-reperfusion ( I∕R) in mice. Methods A total of 120 healthy male C57BL∕6 mice, aged 10-12 weeks, weighing 20-25 g, were divided into 4 groups ( n=30 each) u-sing a random number table method: control group ( group C) , cerebral I∕R group ( group I∕R) , precondi-tioning with EA at non-acupoint+cerebral I∕R group ( group S+I∕R) and preconditioning with EA at Baihui acupoint + cerebral I∕R group ( group E+I∕R) . The cerebral I∕R injury model was established by occlusion of bilateral common carotid arteries followed by reperfusion for 72 h in mice anesthetized with halothane or chloral hydrate in group I∕R. Group S+I∕R received EA at the points 2 mm lateral to the acupoints of Baihui for 5 consecutive days, and then the cerebral I∕R injury model was established. Group E+I∕R received EA at Baihui acupoints with a sparse-dense wave at an intensity of 1 mA and a frequency of 2 Hz∕15 Hz for 30 min once a day for 5 consecutive days, and then the cerebral I∕R injury model was established. Neurobe-havioral score was assessed at 24 and 48 h of reperfusion. Then 5 mice in each group were sacrificed, and the hippocampal tissues were obtained and stained with haematoxylin and eosin for examination of the patho-logical changes in hippocampal CA1 region and for determination of the expression of IκB-α, NF-κB, ICAM-1, interleukin-6 ( IL-6) , IL-1β protein and mRNA by Western blot and real-time polymerase chain reaction, respectively. Results Compared with group C, neurobehavioral score was significantly in-creased, and the expression of hippocampal IκB-α, NF-κB, ICAM-1, IL-6 and IL-1βprotein and mRNA was up-regulated in I∕R, S+I∕R and E+I∕R groups ( P<0. 05) . Compared with group I∕R, neurobehavioral score was significantly decreased, and the expression of hippocampal IκB-α, NF-κB, ICAM-1, IL-6 and IL-1β protein and mRNA was down-regulated in group E+I∕R (P<0. 05), and no significant change was found in the parameters mentioned above in group S+I∕R (P>0. 05). Compared with group S+I∕R, neu-robehavioral score was significantly decreased, and the expression of hippocampal IκB-α, NF-κB, ICAM-1, IL-6 and IL-1β protein and mRNA was down-regulated in group E+I∕R ( P<0. 05) . Conclusion The mechanism by which EA preconditioning attenuates cerebral I∕R injury may be related to inhibiting activation of hippocampal IκB-α∕NF-κB∕ICAM-1 signaling pathway in mice.

RESUMEN

It has been reported that ischemic preconditioning (IPC) and adiponectin (APN) are cardioprotective in many cardiovascular disorders. However, whether APN mediates the effect of IPC on myocardial injury has not been elucidated. This study was conducted to investigate whether IPC affects myocardial ischemic injury by increasing APN expression. Male adult rats with cardiac knockdowns of APN and its receptors via intramyocardial small-interfering RNA injection were subjected to IPC and then myocardial infarction (MI) at 24 h after IPC. Globular APN (gAd) was injected at 10 min before MI. APN mRNA and protein levels in myocardium as well as the plasma APN concentration were markedly high at 6 and 12 h after IPC. IPC ameliorated myocardial injury as evidenced by improved cardiac functions and a reduced infarct size. Compared with the control MI group, rats in the IPC + MI group had elevated levels of left ventricular ejection fraction and fractional shortening and a smaller MI size (P < 0.05). However, the aforementioned protective effects were ameliorated in the absence of APN and APN receptors, followed by the inhibition of AMP-activated protein kinase (AMPK) phosphorylation, but reversed by gAd treatment in wild-type rats, and AMPK phosphorylation increased (P < 0.05). Overall, our results suggest that the cardioprotective effects of IPC are partially due to upregulation of APN and provide a further insight into IPC-mediated signaling effects.

Asunto(s)

Adiponectina/genética , Precondicionamiento Isquémico Miocárdico , Infarto del Miocardio/prevención & control , Daño por Reperfusión Miocárdica/prevención & control , Miocardio/metabolismo , Receptores de Adiponectina/genética , Proteínas Quinasas Activadas por AMP/genética , Proteínas Quinasas Activadas por AMP/metabolismo , Adiponectina/antagonistas & inhibidores , Adiponectina/metabolismo , Animales , Regulación de la Expresión Génica , Pruebas de Función Cardíaca , Masculino , Infarto del Miocardio/genética , Infarto del Miocardio/metabolismo , Infarto del Miocardio/patología , Daño por Reperfusión Miocárdica/genética , Daño por Reperfusión Miocárdica/metabolismo , Daño por Reperfusión Miocárdica/patología , Miocardio/patología , ARN Interferente Pequeño/genética , ARN Interferente Pequeño/metabolismo , Ratas , Ratas Sprague-Dawley , Receptores de Adiponectina/antagonistas & inhibidores , Receptores de Adiponectina/metabolismo , Transducción de Señal , Volumen Sistólico/fisiología

RESUMEN

The aim of this study was to investigate the effect of sirtinol, as an inhibitor of sirtuin NAD-dependent histone deacetylases, on myocardial ischemia reperfusion injury following early and late ischemia preconditioning (IPC). Rats underwent sustained ischemia and reperfusion (IR) alone or proceeded by early or late IPC. Sirtinol (S) was administered before IPC. Arrhythmias were evaluated based on the Lambeth model. Infarct size (IS) was measured using triphenyltetrazolium chloride staining. The transcription level of antioxidant-coding genes was assessed by real-time PCR. In early and late IPC groups, IS and the number of arrhythmia were significantly decreased (P < 0.05 and P < 0.01 vs IR, respectively). In S + early IPC, incidences of arrhythmia and IS were not different compared with the early IPC group. However, in S + late IPC the IS was different from the late IPC group (P < 0.05). In late IPC but not early IPC, transcription levels of catalase (P < 0.01) and Mn-SOD (P < 0.05) increased, although this upregulation was not significant in the S + late IPC group. Our results are consistent with the notion that different mechanisms are responsible for early and late IPC. In addition, sirtuin NAD-dependent histone deacetylases may be implicated in late IPC-induced cardioprotection.

Asunto(s)

Arritmias Cardíacas/prevención & control , Benzamidas/farmacología , Inhibidores de Histona Desacetilasas/farmacología , Precondicionamiento Isquémico Miocárdico/métodos , Infarto del Miocardio/prevención & control , Daño por Reperfusión Miocárdica/prevención & control , Miocardio/patología , Naftoles/farmacología , Animales , Arritmias Cardíacas/enzimología , Arritmias Cardíacas/genética , Arritmias Cardíacas/fisiopatología , Catalasa/genética , Catalasa/metabolismo , Modelos Animales de Enfermedad , Regulación Enzimológica de la Expresión Génica , Masculino , Infarto del Miocardio/enzimología , Infarto del Miocardio/genética , Infarto del Miocardio/patología , Daño por Reperfusión Miocárdica/enzimología , Daño por Reperfusión Miocárdica/genética , Daño por Reperfusión Miocárdica/patología , Miocardio/enzimología , Ratas Wistar , Sirtuina 1/antagonistas & inhibidores , Sirtuina 1/metabolismo , Sirtuina 2/antagonistas & inhibidores , Sirtuina 2/metabolismo , Superóxido Dismutasa/genética , Superóxido Dismutasa/metabolismo , Factores de Tiempo

RESUMEN

OBJECTIVE: To study the protective effect of total flavonoid in rabdosia rubescens on BIT model by brain ischemic tolerance (hereinafter BIT) model of mice. METHOD: BIT model is used to block bilateral common carotid arteries and to copy BIT model of mice. After 10 min of transient ischemia for rats in preconditioning group, the mice in the nimodipine group and naoluotong capsule group were given the total flavonoid in rabdosia rubescens (300 mg/kg, 150 mg/kg, 75 mg/kg) for gavage, sham operation group, ischemia/reperfusion injury (hereinafter IRI) group and BIT group were fed with the same volume of 0.5% sodium carboxymethyl cellulose (CMC) once a day for 5 days. After administration for 1 h on day 5 (120 h), the rats in the other groups except for the sham operation group were treated with blood flow block for 30 min and reperfusion for 22 h. The serum NSE level were measured and the brain NO content and NOS activity changes was measured to observe the histopathological changes of brain tissue. RESULTS: BIT models of mice and in rats were both successfully replicated. The total flavonoid in rabdosia rubescens can decrease the mortality of mice, decrease serum NSE level, increase the content of NO and the activity of NOS in the brain tissue of mice, and improve the pathological damage of cortex and hippocampus of mice. CONCLUSION: The total flavonoid in rabdosia rubescens can stimulate an endogenous protective mechanism by inducing the release of low levels of cytokines NO and NOS, which reduces the release of serum NSE, relieves the brain tissue ischemia-reperfusion injury, and further improves the protection effect of ischemic preconditioning on brain injury. The damage of brain tissue ischemia and reperfusion, and further improve the ischemia Protective effect of preconditioning on brain injury.

RESUMEN

Objective To investigate the difference of late-phase of limb ischemia preconditioning (L-LIP) verse early-phase (E-LIP) on patients with percutaneous coronary intervention (PCI).Methods A total of 160 patients with unstable angina pectoris who were planned to undergo PCI were divided equally into two groups at random.The late-phase of limb ischemia preconditioning group (80 patients) were provided with L-LIP (three 5-minute inflations up to 200mmHg by applying the sphygmomanometer cuff around the right upper arm,followed by 5-min intervals of reperfusion,twice a day) 3 days before PCI.The Earlyphase of limb ischemia preconditioning group (80 patients) were provided with E-LIP (method as above)2 hours before PCI.Comparison of procedural parameters during PCI and the levels of cTnT,CK-MB,hs-CRP were made 24 hours after PCI.Estimation of the rate of adverse events at 1 year between the two groups was evaluated by Kaplan-Meier analysis.Results Compared to the E-LIP group,the rates of angina,arrhythmia and TIMI flow ≤ 2 during PCI were significantly lower in the L-LIP group (all P ＜ 0.05).At 24 hours after PCI,the levels of cTnT and CK-MB were declined more significantly in the L-LIP group[(11.52±2.41) pg/ml vs.(27.53±4.78)pg/ml,P =0.021;(14.11±2.87)Iu/L vs.(30.23±5.17)Iu/L,P =0.032].There was no difference in the level of hs-CRP between the 2 groups [(128±0.71)mg/dl vs.(1.33±0.69)mg/dl,P =0.742].The Kaplan-Meier survival curve showed that the incidence rate of adverse events in the L-LIP group at l year was lower than the E-LIP group (3.75％ vs.13.75％,P =0.024).Conclusions L-LIP is more effective to in protecting myocardial cell in patients with unstable angina pectoris undergoing elective PCI and may reduce the rate of future adverse event.

RESUMEN

Cardio-vascular diseases are the leading cause of morbidity and mortality. Ischemia is a state of oxygen deprivation in tissues, whereas reperfusion is restoration of blood flow in ischemic tissues. Myocardial damage of tissue during reperfusion after ischemic insult is known as myocardial ischemia-reperfusion (I/R) injury. It induces damage to cardiac muscle via increasing expression of oxygen, sodium and calcium ions which are responsible in the activation of proteases and cell death. Heart renin angiotensin system (RAS) plays an important role in the myocardial ischemia and reperfusion injury. Angiotensin (1-7) is responsible for vasodilation and angiotensin II for vasoconstriction. Here-in we reviewed how myocardial I/R injury sets in by up-regulation of angiotensin II that leads to increased infarct size, which can be reduced by the use of ACE inhibitors, ACE2 activators and angiotensin II antagonist.

Asunto(s)

Precondicionamiento Isquémico Miocárdico/métodos , Daño por Reperfusión Miocárdica/metabolismo , Miocardio/metabolismo , Sistema Renina-Angiotensina/fisiología , Animales , Humanos

RESUMEN

Remote ischemia preconditioning (rIPC), short cycles of ischemia (I) and reperfusion (R) of a region remote from the heart, protects against myocardial I/R injury. This effect is triggered by endothelial derived nitric oxide (NO) production. Red blood cells (RBC) are also capable of NO production and it is hypothesized that the beneficial effect of rIPC in terms of cardioprotection is strengthened by increased RBC dependent NO production and improved RBC function after rIPC maneuver. For this purpose, twenty male participants were subjected to four cycles of no-flow ischemia with subsequent reactive hyperemia within the forearm. Blood sampling and measurement of blood pressures and heart rate were carried out pre intervention, after each cycle and 15 min post intervention at both the non-treated and treated arm. These are the first results that show improved RBC deformability in the treated arm after rIPC cycles 1- 4 caused by significantly increased RBC-NO synthase activation. This in turn was associated to increased NO production in both arms after rIPC cycles 3 + 4. Also, systolic and diastolic blood pressures were decreased after rIPC. The findings lead to the conclusion that the cardioprotective effects associated with rIPC include improvement of the RBC-NOS/NO signaling in RBC.

Asunto(s)

Deformación Eritrocítica/fisiología , Eritrocitos/metabolismo , Isquemia/sangre , Precondicionamiento Isquémico/métodos , Óxido Nítrico Sintasa/metabolismo , Óxido Nítrico/metabolismo , Adulto , Humanos , Masculino

RESUMEN

INTRODUCTION: The Langendorff perfused isolated mouse heart model is commonly used to assess the efficacy of cardioprotective therapies, although the duration of ischemia and reperfusion vary considerably between different laboratories. We aimed to provide a thorough characterization of the model with different durations of ischemia and reperfusion by means of 2 different end points-infarct size (IS) using triphenyltetrazolium staining and lactate dehydrogenase (LDH) release. METHODS: C57/BL6 mice hearts were retrograde perfused on a Langendorff apparatus and allocated into 9 groups in a 3 × 3 factorial design-3 ischemic durations (25, 35, and 45 minutes) matched by 3 reperfusion durations (60, 120, and 180 minutes). A protocol of ischemic preconditioning (IPC) was applied to investigate IS and LDH kinetics with different ischemic durations. RESULTS: Infarct size progressively increased with the duration of both ischemia and reperfusion and was found to be independently associated with both determinants. In terms of LDH release kinetics, a peak was observed within the first 10 to 15 minutes of reperfusion and steadily declined thereafter, although a second smaller peak was observed in the 25-minute ischemia group. Only LDH peak release was associated with the ischemia length, with area under the curve (AUC) failing to follow ischemic duration. Interestingly, while IPC reduced IS in all ischemic durations investigated, a significant attenuation of LDH AUC was only observed in the 25-minute index ischemia group. Only a moderately positive correlation was observed between IS and LDH peak (R = .547, P = .006) and AUC (R = .664, P < .001). CONCLUSION: Myocardial IS measured by triphenyltetrazolium staining depends on both the duration of ischemia and the length of the reperfusion period. The LDH assessment may not be the most reliable tool to assess IS and/or to examine cardioprotective effectiveness at various times of ischemia.

Asunto(s)

Preparación de Corazón Aislado , L-Lactato Deshidrogenasa/metabolismo , Infarto del Miocardio/enzimología , Infarto del Miocardio/patología , Daño por Reperfusión Miocárdica/enzimología , Daño por Reperfusión Miocárdica/patología , Reperfusión Miocárdica/métodos , Miocardio/enzimología , Miocardio/patología , Animales , Área Bajo la Curva , Biomarcadores/metabolismo , Modelos Animales de Enfermedad , Masculino , Ratones Endogámicos C57BL , Reperfusión Miocárdica/efectos adversos , Valor Predictivo de las Pruebas , Reproducibilidad de los Resultados , Coloración y Etiquetado/métodos , Factores de Tiempo

RESUMEN

BACKGROUND: Ischemia-reperfusion (IR) causes acute kidney injury (AKI), and ischemia pretreatment may exert protection. Mitogen-activated protein kinase kinase 3 (MKK3), which is involved in the signal transduction pathway in IR-induced injury, is a potential target of miR-21. We aimed to verify the targeting regulation of miR-21 on MKK3 and to explore the effects of miR-21-mediated MKK3 expression changes in AKI. METHODS: Vectors containing the MKK3 3'UTR and mutated MKK3-3U-M were constructed and co-transfected with nonsense miR, miR-21-5p mimics or inhibitor in HEK293 cells. Gene expressions were detected by dual luciferase reporter assay. The effects of miR-21 on mRNA and protein of MKK3 were investigated in HK-2 cells. Male C57BL/6J mice were treated with ischemic preconditioning (IPC) and IR. Kidney functions were assessed through monitoring serum creatinine (Scr) and blood urea nitrogen (BUN). Pathological changes were observed and scored with histological samples of kidney. Expression levels of miR-21, MKK3, interleukin (IL)-6, tumor necrosis factor (TNF)-α before and after IPC and IR were examined by real-time polymerase chain reaction and/or immunohistochemistry. RESULTS: miR-21 regulated the expression of MKK3 via 3'UTR. Following IR, MKK3, IL-6 and TNF-α levels were increased. Scr, BUN and pathological injuries were aggravated, and miR-21 expression was increased. IPC increased miR-21 levels ahead of IR and inhibited the increases in MKK3, IL-6 and TNF-α levels and the aggravation of Scr, BUN and pathological injuries. CONCLUSIONS: miR-21 targets MKK3 in vivo and in vitro, inhibiting the downstream factors IL-6 and TNF-α. Therefore, miR-21 might be involved in protection of IPC against IR of the kidney.

Asunto(s)

Lesión Renal Aguda/prevención & control , Precondicionamiento Isquémico , Riñón/enzimología , MAP Quinasa Quinasa 3/metabolismo , MicroARNs/metabolismo , Daño por Reperfusión/prevención & control , Regiones no Traducidas 3' , Lesión Renal Aguda/enzimología , Lesión Renal Aguda/genética , Lesión Renal Aguda/patología , Lesión Renal Aguda/fisiopatología , Animales , Sitios de Unión , Biomarcadores/sangre , Nitrógeno de la Urea Sanguínea , Creatinina/sangre , Modelos Animales de Enfermedad , Células HEK293 , Humanos , Interleucina-6/sangre , Riñón/patología , Riñón/fisiopatología , MAP Quinasa Quinasa 3/genética , Masculino , Ratones Endogámicos C57BL , MicroARNs/genética , Daño por Reperfusión/enzimología , Daño por Reperfusión/genética , Daño por Reperfusión/patología , Daño por Reperfusión/fisiopatología , Transducción de Señal , Factores de Tiempo , Transfección , Factor de Necrosis Tumoral alfa/sangre , Regulación hacia Arriba

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Ischemic heart diseases are the leading cause of death with increasing numbers of patients worldwide. Despite advances in revascularization techniques, angiogenic therapies remain highly attractive. Physiological ischemia training, which is first proposed in our laboratory, refers to reversible ischemia training of normal skeletal muscles by using a tourniquet or isometric contraction to cause physiologic ischemia for about 4 weeks for the sake of triggering molecular and cellular mechanisms to promote angiogenesis and formation of collateral vessels and protect remote ischemia areas. Physiological ischemia training therapy augments angiogenesis in the ischemic myocardium by inducing differential expression of proteins involved in energy metabolism, cell migration, protein folding, and generation. It upregulates the expressions of vascular endothelial growth factor, and induces angiogenesis, protects the myocardium when infarction occurs by increasing circulating endothelial progenitor cells and enhancing their migration, which is in accordance with physical training in heart disease rehabilitation. These findings may lead to a new approach of therapeutic angiogenesis for patients with ischemic heart diseases. On the basis of the promising results in animal studies, studies were also conducted in patients with coronary artery disease without any adverse effect in vivo, indicating that physiological ischemia training therapy is a safe, effective and non-invasive angiogenic approach for cardiovascular rehabilitation. Preconditioning is considered to be the most protective intervention against myocardial ischemia-reperfusion injury to date. Physiological ischemia training is different from preconditioning. This review summarizes the preclinical and clinical data of physiological ischemia training and its difference from preconditioning.

RESUMEN

Remote ischemia preconditioning (RIPC) and remote preconditioning of trauma (RPCT) are two methods used to induce a cardioprotective function against ischemia/reperfusion injury (IRI). However, the underlying mechanisms of these two methods differ. The aim of the present study was to investigate the cardioprotective function of the two methods, and also observe whether combining RIPC with RPCT enhanced the protective effect. In total, 70 male Sprague Dawley rats were randomly divided into five groups, which included the sham, control, RIPC + RPCT, RPCT and RIPC groups. With the exception of the sham group, all the rats were subjected to myocardial IRI through the application of 30 min occlusion of the left coronary artery and 180 min reperfusion. Serum cardiac troponin I (cTnI) levels, myocardial infarct size (IS) and the cardiomyocyte apoptotic index (AI) were assessed. The levels of serum cTnI were lower in the experimental groups when compared with the control group (control, 58.59±12.50 pg/ml; RIPC + RPCT, 46.05±8.62 pg/ml; RPCT, 45.98±11.24 pg/ml; RIPC, 43.46±5.05 pg/ml; P<0.05, vs. control), and similar results were observed for the myocardial IS (control, 48.34±6.79%; RIPC + RPCT, 29.64±4.51%; RPCT, 29.05±8.51%; RIPC, 27.72±6.27%; P<0.05, vs. control) and the AI (control, 31.75±10.65%; RIPC + RPCT, 18.32±9.30%; RPCT, 18.51±9.26%; RIPC, 20.41±3.86%; P<0.05, vs. control). However, no statistically significant differences were observed among the three experimental groups (P>0.05). Therefore, RIPC and RPCT exhibit cardioprotective effects when used alone or in combination. However, a combination of RIPC and RPCT does not enhance the cardioprotective effect observed with the application of either single method. Therefore, for patients undergoing major abdominal surgery, RIPC was considered to be unnecessary, while for patients undergoing other types of non-cardiac major surgery and minimally invasive interventional surgery, RIPC may be useful. In addition, patients with embolism diseases are also liable to IRI when reperfusion treatment such as thrombolysis is conducted. Thus RIPC may also be beneficial for these patients.