A benefit-finding intervention for family caregivers of persons with Alzheimer disease: study protocol of a randomized controlled trial

Background

Patients with ST-elevation myocardial infarction (STEMI) not treated with primary or rescue percutaneous coronary intervention (PCI) are at risk for recurrent ischemia, especially when viability in the infarct-area is present. Therefore, an invasive strategy with PCI of the infarct-related coronary artery in patients with viability would reduce the occurrence of a composite end point of death, reinfarction, or unstable angina (UA).

Methods

Patients admitted with an (sub)acute myocardial infarction, who were not treated by primary or rescue PCI, and who were stable during the first 48 hours after the acute event, were screened for the study. Eventually, we randomly assigned 216 patients with viability (demonstrated with low-dose dobutamine echocardiography) to an invasive or a conservative strategy. In the invasive strategy stenting of the infarct-related coronary artery was intended with abciximab as adjunct treatment. Seventy-five (75) patients without viability served as registry group. The primary endpoint was the composite of death from any cause, recurrent myocardial infarction (MI) and unstable angina at one year. As secondary endpoint the need for (repeat) revascularization procedures and anginal status were recorded.

Results

The primary combined endpoint of death, recurrent MI and unstable angina was 7.5% (8/106) in the invasive group and 17.3% (19/110) in the conservative group (Hazard ratio 0.42; 95% confidence interval [CI] 0.18-0.96; p = 0.032). During follow up revascularization-procedures were performed in 6.6% (7/106) in the invasive group and 31.8% (35/110) in the conservative group (Hazard ratio 0.18; 95% CI 0.13-0.43; p < 0.0001). A low rate of recurrent ischemia was found in the non-viable group (5.4%) in comparison to the viable-conservative group (14.5%). (Hazard-ratio 0.35; 95% CI 0.17-1.00; p = 0.051).

Conclusion

We demonstrated that after acute MI (treated with thrombolysis or without reperfusion therapy) patients with viability in the infarct-area benefit from a strategy of early in-hospital stenting of the infarct-related coronary artery. This treatment results in a long-term uneventful clinical course. The study confirmed the low risk of recurrent ischemia in patients without viability.

Trial registration

ClinicalTrials.gov: NCT00149591.     

Troponin elevation in acute ischemic stroke (TRELAS) - protocol of a prospective observational trial

Background  

Levels of the cardiac muscle regulatory protein troponin T (cTnT) are frequently elevated in patients with acute ischemic stroke and elevated cTnT predicts poor outcome and mortality. The pathomechanism of troponin release may relate to co-morbid coronary artery disease and myocardial ischemia or, alternatively, to neurogenic cardiac damage due to autonomic activation after acute ischemic stroke. Therefore, there is uncertainty about how acute ischemic stroke patients with increased cTnT levels should be managed regarding diagnostic and therapeutic workup.     

Hyperuricemia and untreated gout are poor prognostic markers among those with a recent acute myocardial infarction

Introduction  

Patients with a history of myocardial infarction (MI) are often at risk for complications, including subsequent MI and death. Use of prognostic markers may aid in preventing these poor outcomes. Hyperuricemia is associated with increased risk for coronary heart disease (CHD) and/or mortality; however, it is unknown if serum urate (sUA) levels predict outcomes in patients with previous MI. The purpose of this study was to assess hyperuricemia as a biomarker of CHD outcomes in such patients.     

α-Lipoic Acid Reduces Infarct Size and Preserves Cardiac Function in Rat Myocardial Ischemia/Reperfusion Injury through Activation of PI3K/Akt/Nrf2 Pathway

Background

The present study investigates the effects and mechanisms of α-Lipoic acid (LA) on myocardial infarct size, cardiac function and cardiomyocyte apoptosis in rat hearts subjected to in vivo myocardial ischemia/reperfusion (MI/R) injury.

Methodology/Principal Findings

Male adult rats underwent 30 minutes of ischemia followed by 3, 24, or 72 h of reperfusion. Animals were pretreated with LA or vehicle before coronary artery ligation. The level of MI/R- induced LDH and CK release, infarct size, cardiomyocyte apoptosis and cardiac functional impairment were examined and compared. Western blot analysis was performed to elucidate the mechanism of LA pretreatment. The level of inflammatory cytokine TNF-α released to serum and accumulated in injured myocardium as well as neutrophil accumulation in injured myocardium were also examined after MI/R injury. Our results reveal that LA administration significantly reduced LDH and CK release, attenuated myocardial infarct size, decreased cardiomyocytes apoptosis, and partially preserved heart function. Western blot analysis showed that LA pretreatment up-regulated Akt phosphorylation and Nrf2 nuclear translocation while producing no impact on p38MAPK activation or nitric oxide (NO) production. LA pretreatment also increased expression of HO-1, a major target of Nrf2. LA treatment inhibited neutrophil accumulation and release of TNF-α. Moreover, PI3K inhibition abolished the beneficial effects of LA.

Conclusions/Significance

This study indicates that LA attenuates cardiac dysfunction by reducing cardiomyoctyes necrosis, apoptosis and inflammation after MI/R. LA exerts its action by activating the PI3K/Akt pathway as well as subsequent Nrf2 nuclear translocation and induction of cytoprotective genes such as HO-1.     

Prognosis of STEMI Patients with Multi-Vessel Disease Undergoing Culprit-Only PCI without Significant Residual Ischemia on Non-Invasive Stress Testing

Aims

In about 50–80% of ST-segment elevation myocardial infarction (STEMI) patients there is significant atherosclerotic disease in other coronary arteries in addition to the culprit vessel. There is substantial controversy as to the optimal revascularization approach in these patients. We sought to compare the outcomes of STEMI patients with multi-vessel disease (MVD) treated with culprit-only primary percutaneous coronary intervention (PPCI) without significant ischemia on subsequent non-invasive testing, to those of STEMI patients with single-vessel disease (SVD).

Methods and Results

Between 2001–2010, 1,540 consecutive patients treated with primary PCI for STEMI were prospectively observed and entered into a comprehensive clinical database. The primary end point was a composite of major adverse cardiac events (MACE), consisting of mortality, re-infarction and revascularization within 1 and 3 years following PPCI (excluding events occurring during the first 30 days). Patients with cardiogenic shock were excluded. The study included 720 patients with SVD and 185 patients with MVD who underwent culprit-only PPCI and had no residual ischemia on subsequent non-invasive stress testing. Patients with MVD were older, more likely to have hypertension or previous MI and less likely to be smokers and present with anterior MI than patients with SVD. One and 3-year MACE rates were similar between the groups. On cox proportional-hazards regression MVD without residual ischemia was not independently associated with MACE and its components.

Conclusions

STEMI patients with MVD treated with culprit only-PCI without significant residual ischemia on non-invasive stress testing appear to have similar prognosis to STEMI patients with SVD.     

Toll-like receptor 3 plays a role in myocardial infarction and ischemia/reperfusion injury

Innate immune and inflammatory responses mediated by Toll like receptors (TLRs) have been implicated in myocardial ischemia/reperfusion (I/R) injury. This study examined the role of TLR3 in myocardial injury induced by two models, namely, myocardial infarction (MI) and I/R. First, we examined the role of TLR3 in MI. TLR3 deficient (TLR3^−/−) and wild type (WT) mice were subjected to MI induced by permanent ligation of the left anterior descending (LAD) coronary artery for 21 days. Cardiac function was measured by echocardiography. Next, we examined whether TLR3 contributes to myocardial I/R injury. TLR3^−/− and WT mice were subjected to myocardial ischemia (45 min) followed by reperfusion for up to 3 days. Cardiac function and myocardial infarct size were examined. We also examined the effect of TLR3 deficiency on I/R-induced myocardial apoptosis and inflammatory cytokine production. TLR3^−/− mice showed significant attenuation of cardiac dysfunction after MI or I/R. Myocardial infarct size and myocardial apoptosis induced by I/R injury were significantly attenuated in TLR3^−/− mice. TLR3 deficiency increases B-cell lymphoma 2 (BCL2) levels and attenuates I/R-increased Fas, Fas ligand or CD95L (FasL), Fas-Associated protein with Death Domain (FADD), Bax and Bak levels in the myocardium. TLR3 deficiency also attenuates I/R-induced myocardial nuclear factor KappaB (NF-κB) binding activity, Tumor necrosis factor alpha (TNF-α) and Interleukin-1 beta (IL-1β) production as well as I/R-induced infiltration of neutrophils and macrophages into the myocardium. TLR3 plays an important role in myocardial injury induced by MI or I/R. The mechanisms involve activation of apoptotic signaling and NF-κB binding activity. Modulation of TLR3 may be an effective approach for ameliorating heart injury in heart attack patients.     

Toll-like receptor 4 deficiency: Smaller infarcts,but nogain in function

Backgound  

It has been reported that Toll-like receptor 4 (TLR4) deficiency reduces infarct size after myocardial ischemia/reperfusion (MI/R). However, measurement of MI/R injury was limited and did not include cardiac function. In a chronic closed-chest model we assessed whether cardiac function is preserved in TLR4-deficient mice (C3H/HeJ) following MI/R, and whether myocardial and systemic cytokine expression differed compared to wild type (WT).     

Depressive Symptoms Are Associated with Mental Stress-Induced Myocardial Ischemia after Acute Myocardial Infarction

Objectives

Depression is an adverse prognostic factor after an acute myocardial infarction (MI), and an increased propensity toward emotionally-driven myocardial ischemia may play a role. We aimed to examine the association between depressive symptoms and mental stress-induced myocardial ischemia in young survivors of an MI.

Methods

We studied 98 patients (49 women and 49 men) age 38–60 years who were hospitalized for acute MI in the previous 6 months. Patients underwent myocardial perfusion imaging at rest, after mental stress (speech task), and after exercise or pharmacological stress. A summed difference score (SDS), obtained with observer-independent software, was used to quantify myocardial ischemia under both stress conditions. The Beck Depression Inventory-II (BDI-II) was used to measure depressive symptoms, which were analyzed as overall score, and as separate somatic and cognitive depressive symptom scores.

Results

There was a significant positive association between depressive symptoms and SDS with mental stress, denoting more ischemia. After adjustment for demographic and lifestyle factors, disease severity and medications, each incremental depressive symptom was associated with 0.14 points higher SDS. When somatic and cognitive depressive symptoms were examined separately, both somatic [β = 0.17, 95% CI: (0.04, 0.30), p = 0.01] and cognitive symptoms [β = 0.31, 95% CI: (0.07, 0.56), p = 0.01] were significantly associated with mental stress-induced ischemia. Depressive symptoms were not associated with ischemia induced by exercise or pharmacological stress.

Conclusion

Among young post-MI patients, higher levels of both cognitive and somatic depressive symptoms are associated with a higher propensity to develop myocardial ischemia with mental stress, but not with physical (exercise or pharmacological) stress.     

Systematic adjudication of myocardial infarction end-points in an international clinical trial

Background

Clinical events committees (CEC) are used routinely to adjudicate suspected end-points in cardiovascular trials, but little information has been published about the various processes used. We reviewed results of the CEC process used to identify and adjudicate suspected end-point (post-enrolment) myocardial infarction (MI) in the large Platelet Glycoprotein IIb/IIIa in Unstable Angina: Receptor Suppression Using Integrilin (Eptifibatide) Therapy (PURSUIT) trial.

Methods

The PURSUIT trial randomised 10,948 patients with acute coronary syndromes to receive eptifibatide or placebo. A central adjudication process was established prospectively to identify all suspected MIs and adjudicate events based on protocol definitions of MI. Suspected MIs were identified by systematic review of data collection forms, cardiac enzyme results, and electrocardiograms. Two physicians independently reviewed all suspected events. If they disagreed whether a MI had occurred, a committee of cardiologists adjudicated the case.

Results

The CEC identified 5005 patients with suspected infarction (46%), of which 1415 (28%) were adjudicated as end-point infarctions. As expected, the process identified more end-point events than did the site investigators. Absolute and relative treatment effects of eptifibatide were smaller when using CEC-determined MI rates rather than site investigator-determined rates. The site-investigator reporting of MI and the CEC assessment of MI disagreed in 20% of the cases reviewed by the CEC.

Conclusions

End-point adjudication by a CEC is important, to provide standardised, systematic, independent, and unbiased assessment of end-points, particularly in trials that span geographic regions and clinical practice settings. Understanding the CEC process used is important in the interpretation of trial results and event rates.     

Exogenous Administration of a Recombinant Variant of TWEAK Impairs Healing after Myocardial Infarction by Aggravation of Inflammation

Background

Tumor necrosis factor-like weak inducer of apoptosis (TWEAK) and its receptor fibroblast growth factor-inducible 14 (Fn14) are upregulated after myocardial infarction (MI) in both humans and mice. They modulate inflammation and the extracellular matrix, and could therefore be important for healing and remodeling after MI. However, the function of TWEAK after MI remains poorly defined.

Methods and results

Following ligation of the left coronary artery, mice were injected twice per week with a recombinant human serum albumin conjugated variant of TWEAK (HSA-Flag-TWEAK), mimicking the activity of soluble TWEAK. Treatment with HSA-Flag-TWEAK resulted in significantly increased mortality in comparison to the placebo group due to myocardial rupture. Infarct size, extracellular matrix remodeling, and apoptosis rates were not different after MI. However, HSA-Flag-TWEAK treatment increased infiltration of proinflammatory cells into the myocardium. Accordingly, depletion of neutrophils prevented cardiac ruptures without modulating all-cause mortality.

Conclusion

Treatment of mice with HSA-Flag-TWEAK induces myocardial healing defects after experimental MI. This is mediated by an exaggerated neutrophil infiltration into the myocardium.     

Comparison of contrast enhanced three dimensional echocardiography with MIBI gated SPECT for the evaluation of left ventricular function

Background

Real-time perfusion (RTP) contrast echocardiography can be used during adenosine stress echocardiography (ASE) to evaluate myocardial ischemia. We compared two different types of RTP power modulation techniques, angiomode (AM) and high-resolution grayscale (HR), with^99mTc-tetrofosmin single-photon emission computed tomography (SPECT) for the detection of myocardial ischemia.

Methods

Patients with known or suspected coronary artery disease (CAD), admitted to SPECT, were prospectively invited to participate. Patients underwent RTP imaging (SONOS 5500) using AM and HR during Sonovue^® infusion, before and throughout the adenosine stress, also used for SPECT. Analysis of myocardial perfusion and wall motion by RTP-ASE were done for AM and HR at different time points, blinded to one another and to SPECT. Each segment was attributed to one of the three main coronary vessel areas of interest.

Results

In 50 patients, 150 coronary areas were analyzed by SPECT and RTP-ASE AM and HR. SPECT showed evidence of ischemia in 13 out of 50 patients. There was no significant difference between AM and HR in detecting ischemia (p = 0.08). The agreement for AM and HR, compared to SPECT, was 93% and 96%, with Kappa values of 0.67 and 0.75, respectively (p < 0.001).

Conclusion

There was no significant difference between AM and HR in correctly detecting myocardial ischemia as judged by SPECT. This suggests that different types of RTP modalities give comparable data during RTP-ASE in patients with known or suspected CAD.     

Rheumatoid arthritis patients receive less frequent acute reperfusion and secondary prevention therapy after myocardial infarction compared with the general population

Introduction  

The 30-day case-fatality rate after acute myocardial infarction (MI) for rheumatoid arthritis (RA) patients is twice that of the general population. This study compared the frequency and timeliness of early reperfusion therapy and treatment with secondary prevention medications after acute MI in RA patients and controls.     

Cardioprotective mechanism of SGLT2 inhibitor against myocardial infarction is through reduction of autosis

Sodium-glucose cotransporter 2 (SGLT2) inhibitors reduce cardiovascular mortality in patients with diabetes mellitus but the protective mechanism remains elusive. Here we demonstrated that the SGLT2 inhibitor, Empagliflozin (EMPA), suppresses cardiomyocytes autosis (autophagic cell death) to confer cardioprotective effects. Using myocardial infarction (MI) mouse models with and without diabetes mellitus, EMPA treatment significantly reduced infarct size, and myocardial fibrosis, thereby leading to improved cardiac function and survival. In the context of ischemia and nutritional glucose deprivation where autosis is already highly stimulated, EMPA directly inhibits the activity of the Na⁺/H⁺ exchanger 1 (NHE1) in the cardiomyocytes to regulate excessive autophagy. Knockdown of NHE1 significantly rescued glucose deprivation-induced autosis. In contrast, overexpression of NHE1 aggravated the cardiomyocytes death in response to starvation, which was effectively rescued by EMPA treatment. Furthermore, in vitro and in vivo analysis of NHE1 and Beclin 1 knockout mice validated that EMPA’s cardioprotective effects are at least in part through downregulation of autophagic flux. These findings provide new insights for drug development, specifically targeting NHE1 and autosis for ventricular remodeling and heart failure after MI in both diabetic and non-diabetic patients.Electronic supplementary materialThe online version of this article (10.1007/s13238-020-00809-4) contains supplementary material, which is available to authorized users     

The Asp298 allele of endothelial nitric oxide synthase is a risk factor for myocardial infarction among patients with type 2 diabetes mellitus

Background

To establish an efficient prophylaxis of coronary artery disease reliable risk stratification is crucial, especially in the high risk population of patients suffering from diabetes mellitus. This prospective study determined the predictive value of coronary calcifications for future cardiovascular events in asymptomatic patients with diabetes mellitus.

Methods

We included 716 patients suffering from diabetes mellitus (430 men, 286 women, age 55.2 ± 15.2 years) in this study. On study entry all patients were asymptomatic and had no history of coronary artery disease. In addition, all patients showed no signs of coronary artery disease in ECG, stress ECG or echocardiography. Coronary calcifications were determined with the Imatron C 150 XP electron beam computed tomograph. For quantification of coronary calcifications we calculated the Agatston score. After a mean observation period of 8.1 ± 1.1 years patients were contacted and the event rate of cardiac death (CD) and myocardial infarction (MI) was determined.

Results

During the observation period 40 patients suffered from MI, 36 patients died from acute CD. The initial Agatston score in patients that suffered from MI or died from CD (475 ± 208) was significantly higher compared to those without cardiac events (236 ± 199, p < 0.01). An Agatston score above 400 was associated with a significantly higher annualised event rate for cardiovascular events (5.6% versus 0.7%, p < 0.01). No cardiac events were observed in patients with exclusion of coronary calcifications. Compared to the Framingham risk score and the UKPDS score the Agatston score showed a significantly higher diagnostic accuracy in the prediction of MI with an area under the ROC curve of 0.77 versus 0.68, and 0.71, respectively, p < 0.01.

Conclusion

By determination of coronary calcifications patients at risk for future MI and CD could be identified within an asymptomatic high risk group of patients suffering from diabetes mellitus. On the other hand future events could be excluded in patients without coronary calcifications.     

Enhanced early after-myocardial infarction concentration of TNF-alpha subsequently increased circulating and myocardial adrenomedullin in spontaneously hypertensive rats

Both inflammatory cytokine tumor necrosis factor-alpha (TNF-alpha) and the cardiac protective peptide adrenomedullin (AM) are increased in cardiac tissues and plasma in patients with myocardial infarction (MI) and chronic heart failure. Recently they have been increasingly recognized as important factors in the pathophysiology of MI and resultant congestive heart failure. Compared with sham-operated spontaneously hypertensive rats (SHR), we investigated myocardial immunoreactivity of TNF-alpha and AM and also their mutual relations in vivo in SHR+MI. Residual myocardial depression after MI was studied also in isolated perfused hearts. In chronic experiments, 24 and 48 h after permanent ligation of the descending anterior branch of the left coronary artery, we examined hemodynamics, plasma and myocardial peptide levels. Left ventricular function was assessed in isolated perfused hearts subjected to "global ischemia and reperfusion" and after induction of "calcium paradox". Circulating and myocardial TNF-alpha concentrations increased early after MI in SHR. Studies with global ischemia and calcium paradox in isolated heart showed early myocardial depression and calcium-dependent gradual increase of left-ventricular end-diastolic pressure. In the SHR+MI myocardial AM concentrations were increased 9- and 49-fold after respective 24 h and culminated 48 h following MI. Circulating and myocardial AM was increased in SHR+MI in association with TNFalpha-induced myocardial depression. The both studied cardiac parameters displayed the beneficial effect of the enhanced myocardial AM concentration.     

TNF-α inhibitor protects against myocardial ischemia/reperfusion injury via Notch1-mediated suppression of oxidative/nitrative stress

TNF-α inhibitor reportedly protects against myocardial ischemia/reperfusion (MI/R) injury. It can also increase Notch1 expression in inflammatory bowel disease, revealing the regulation of Notch1 signaling by TNF-α inhibitor. However, the interaction between TNF-α inhibitor and Notch1 signaling in MI/R remains unclear. This study aimed to determine the involvement of TNF-α inhibitor with Notch1 in MI/R and delineate the related mechanism. Notch1-specific small interfering RNA (20 μg) or Jagged1 (a Notch ligand, 12 μg) was delivered through intramyocardial injection. Forty-eight hours after injection, mice received 30 min of myocardial ischemia followed by 3 h (for cell apoptosis and oxidative/nitrative stress) or 24 h (for infarct size and cardiac function) of reperfusion. Ten minutes before reperfusion, mice randomly received an intraperitoneal injection of vehicle, etanercept, diphenyleneiodonium, 1400W, or EUK134. Finally, downregulation of Notch1 significantly reversed the alleviation of MI/R injury induced by etanercept, as evidenced by enlarged myocardial infarct size, suppressed cardiac function, and increased myocardial apoptosis. Moreover, Notch1 blockade increased the expression of inducible NO synthase (iNOS) and gp^91phox, enhanced NO and superoxide production, and accelerated their cytotoxic reaction product, peroxynitrite. Furthermore, NADPH inhibition with diphenyleneiodonium or iNOS suppression with 1400W mitigated the aggravation of MI/R injury induced by Notch1 downregulation in mice treated with etanercept. Additionally, either Notch1 activation with Jagged1 or peroxynitrite decomposition with EUK134 reduced nitrotyrosine content and attenuated MI/R injury. These data indicate that MI/R injury can be attenuated by TNF-α inhibitor, partly via Notch1 signaling-mediated suppression of oxidative/nitrative stress.     

Did Clinical Trials in Which Erythropoietin Failed to Reduce Acute Myocardial Infarct Size Miss a Narrow Therapeutic Window?

Background

To test a hypothesis that in negative clinical trials of erythropoietin in patients with acute myocardial infarction (MI) the erythropoietin (rhEPO) could be administered outside narrow therapeutic window. Despite overwhelming evidence of cardioprotective properties of rhEPO in animal studies, the outcomes of recently concluded phase II clinical trials have failed to demonstrate the efficacy of rhEPO in patients with acute MI. However, the time between symptoms onset and rhEPO administration in negative clinical trials was much longer that in successful animal experiments.

Methodology/Principal Findings

MI was induced in rats either by a permanent ligation of a descending coronary artery or by a 2-hr occlusion followed by a reperfusion. rhEPO, 3000 IU/kg, was administered intraperitoneally at the time of reperfusion, 4 hrs after beginning of reperfusion, or 6 hrs after permanent occlusion. MI size was measured histologically 24 hrs after coronary occlusion. The area of myocardium at risk was similar among groups. The MI size in untreated rats averaged ∼42% of area at risk, or ∼24% of left ventricle, and was reduced by more than 50% (p<0.001) in rats treated with rhEPO at the time of reperfusion. The MI size was not affected by treatment administered 4 hrs after reperfusion or 6 hrs after permanent coronary occlusion. Therefore, our study in a rat experimental model of MI demonstrates that rhEPO administered within 2 hrs of a coronary occlusion effectively reduces MI size, but when rhEPO was administered following a delay similar to that encountered in clinical trials, it had no effect on MI size.

Conclusions/Significance

The clinical trials that failed to demonstrate rhEPO efficacy in patients with MI may have missed a narrow therapeutic window defined in animal experiments.     

Unbound free fatty acid concentrations are increased in cardiac ischemia

Monitoring increased plasma unbound free fatty acid (FFA_u) concentrations has been proposed as a biomarker for myocardial ischemia. In the current study, 30 acute coronary syndrome (ACS) patients presenting in the emergency department, with chest pain within 12 h of onset, were clinically evaluated along with serial cardiac troponin I (cTnI) and FFA_u measurements. Increased FFA_u were found in 28 of 30 (93%) of ACS patients, ranging from 2.0 to 430 nM. For the nine ACS patients with myocardial infarction (MI), FFA_u levels were increased at presentation for all (100%). In contrast, cTnI was increased in only 9 of 30 (30%) patients, mean 0.7 μg/L, and in only 2 of 9 (22%) MI patients, mean 1.3 μg/L. During the 24 h following admission, cTnI increased in all 9 MI patients. FFA_u concentrations increased in every sample in which cTnI increased. Our findings suggest that FFA_u is increased in ischemia regardless of the presence or absence of myocardial necrosis, as reflected by increased or normal cTnI, respectively.     

Leukocyte and endothelial cell adhesion molecules in a chronic murine model of myocardial reperfusion injury

Expression of endothelial and leukocyte cell adhesion molecules is a principal determinant of polymorphonuclear neutrophil (PMN) recruitment during inflammation. It has been demonstrated that pharmacological inhibition of these molecules can attenuate PMN influx and subsequent tissue injury. We determined the temporal expression of alpha-granule membrane protein-40 (P-selectin), endothelial leukocyte adhesion molecule 1 (E-selectin), and intercellular cell adhesion molecule 1 (ICAM-1) after coronary artery occlusion and up to 3 days of reperfusion. The expression of all of these cell adhesion molecules peaked around 24 h of reperfusion. We determined the extent to which these molecules contribute to PMN infiltration by utilizing mice deficient (-/-) in P-selectin, E-selectin, ICAM-1, and CD18. Each group underwent 30 min of in vivo, regional, left anterior descending (LAD) coronary artery ischemia and 24 h of reperfusion. PMN accumulation in the ischemic-reperfused (I/R) zone was assessed using histological techniques. Deficiencies of P-selectin, E-selectin, ICAM-1, or CD18 resulted in significant (P < 0.05) attenuation of PMN infiltration into the I/R myocardium (MI/R). In addition, P-selectin, E-selectin, ICAM-1, and CD18 -/- mice exhibited significantly (P < 0.05) smaller areas of necrosis after MI/R compared with wild-type mice. These data demonstrate that MI/R induces coronary vascular expression of P-selectin, E-selectin, and ICAM-1 in mice. Furthermore, genetic deficiency of P-selectin, E-selectin, ICAM-1, or CD18 attenuates PMN sequestration and myocardial injury after in vivo MI/R. We conclude that P-selectin, E-selectin, ICAM-1, and CD18 are involved in the pathogenesis of MI/R injury in mice.     

Acupuncture Promotes Angiogenesis after Myocardial Ischemia through H3K9 Acetylation Regulation at VEGF Gene

Background

Acupuncture exerts cardioprotective effects on several types of cardiac injuries, especially myocardial ischemia (MI), but the mechanisms have not yet been well elucidated. Angiogenesis mediated by VEGF gene expression and its modification through histone acetylation has been considered a target in treating myocardial ischemia. This study aims to exam whether modulation of angiogenesis through H3K9 acetylation regulation at VEGF gene is one possible cardioprotective mechanism of acupuncture.

Results

We generated rat MI models by ligating the left anterior descending coronary artery and applied electroacupuncture (EA) treatment at the Neiguan (PC6) acupoint. Our results showed that acupuncture reversed the S-T segment change, reduced Q-wave area, decreased CK, CK-MB, LDH levels, mitigated myocardial remodeling, and promoted microvessel formation in the MI heart. RNA-seq analysis showed that VEGF-induced angiogenesis signaling was involved in the modulation of EA. Western blot results verified that the protein expressions of VEGF, Ras, phospho-p44/42 MAPK, phospho-p38 MAPK, phospho-SAPK/JNK and Akt, were all elevated significantly by EA treatment in the MI heart. Furthermore, increased H3K9 acetylation was also observed according with the VEGF. ChIP assay confirmed that EA treatment could notably stimulate the recruitment of H3K9ace at the VEGF promoter.

Conclusions

Our study demonstrates for the first time that acupuncture can effectively up-regulate VEGF expression through H3K9 acetylation modification directly at the VEGF promoter and hence activate VEGF-induced angiogenesis in rat MI models. We employed high throughput sequencing in this study and, for the first time, generated genome-wide gene expression profiles both in the rat MI model and in acupuncture treatment.