Novel avenues for cell therapy in acute myocardial infarction

Genus Ziziphus for the treatment of chronic inflammatory diseases

Natural products and traditional medicine are rich sources for developing therapeutics for chronic inflammatory diseases. However, the way from natural products/traditional medicines to Western pharmaceutical practices is not always straightforward. According to the World Health Organization (WHO), chronic diseases are the greatest threat to human health. 3 of 5 people die due to chronic inflammatory disorders worldwide like chronic respiratory diseases, stroke, cardiovascular diseases, cancer, diabetes, and obesity. Various nonsteroidal anti-inflammatory drugs (NSAIDs) are used to reduce inflammation and pain, but there are many side effects of these drugs' administration. Medicinal plants have therapeutic anti-inflammatory effects with low or no side effects. Ziziphus plant species are generally safe and not toxic to humans. Many studies on the Ziziphus species have shown that their therapeutic properties are attributed to the roots, leaves and fruits. Unfortunately, Ziziphus species from different regions worldwide with anti-inflammatory properties have not been documented in a single review paper. Therefore, it is crucial to establish ethnobotanical knowledge and applications of Ziziphus species against chronic inflammatory diseases. The current article exhaustively reviews phytochemical profile, pharmacological studies, toxicological effects, and ethnobotanical uses of Genus Ziziphus in chronic anti-inflammatory diseases. The present review article also highlights the most promising experimental data on Ziziphus extracts and pure compounds active in clinical trials and animal models of chronic inflammatory diseases. This review would be a valuable resource for contemporary researchers in the field to understand the promising role of the Ziziphus genus in chronic inflammatory disorders.

Effect of Training with or without Ziziphus Jujuba Extract on Cardiokines in Heart Tissue of Myocardial Infarcted Rats

BACKGROUND

Today, the importance of physical activity as a preventative way for cardiovascular disease has attracted much attention.The aim of this study is to investigate the effect of 6 weeks of interval training with or without extract of Ziziphus jujuba on lipocalcin-2 (LCN2) and adiponectin levels in heart tissue in male Wistar rats with myocardial infarction.

METHODS

Thirty male Wistar rats (mean weight, 180-220 g and age, 2-3 months) were divided into five groups, including (1) Healthy control; (2) Isoprenaline-treated group (ISO); (3) ISO + jujube extracts (JE); (4) Trained ISO rats; and (5) Trained ISO rats + JE. Exercise was performed (5 days/week, for 6 week including 54-min cycles with speed of 23 m/min and 54-min cycles with speed of 15 m/min). After 48 h of the last training session, the rats were sacrificed, and their heart tissue was excised. The significant level of statistical data was analyzed by one-way ANOVA test.

RESULTS

LCN2 levels significantly decreased in trained ISO rats + JE group after 6 weeks of interval training with JE consumption, compared to ISO group. However, the consumption of jujuba extracts with and without interval training did not show any significant changes in adiponectin levels of rat's heart tissue, compared to ISO (P < 0.05).

CONCLUSIONS

Because the LCN2 inflammatory factor decreased after 6 weeks of exercise and consumption of the extract, it seems that performing interval training with JE consumption can be an effective method in the cardiac rehabilitation phase after a heart attack.

Melatonin prevents adverse myocardial infarction remodeling via Notch1/Mfn2 pathway

Mitochondrial dysfunction is linked with myocardial infarction (MI), a disorder in which Notch1 has attracted increasing attention. However, the involvement of Notch1 in mitochondrial impairment after an MI is poorly understood, as is the role of mitochondrial fusion-associated protein 2 (Mfn2). Moreover, whether melatonin potentiates the Notch1/Mfn2 pathway in post-MI cardiac damage remains unclear. In our study, small interfering RNAs against Notch1 or Mfn2 and Jagged1 peptide were delivered via intramyocardial injection. At 3 days after these treatments, MI was induced by ligation of the anterior descending branch. We found that this ablation of Notch1 or Mfn2 aggravated post-MI injury, including worsened mitochondrial damage and increased generation of reactive oxygen species (ROS). In contrast, Jagged1 improved mitochondrial structure and function, decreased ROS production and attenuated post-MI injury. Interestingly, though Mfn2 expression was mildly regulated by Notch1 signaling in myocardium, Mfn2 deficiency nearly eliminated the cardioprotection by Jagged1, as evidenced by suppressed cardiac function, aggravated myocardial fibrosis, increased cell apoptosis, worsened mitochondrial impairment and enhanced oxidative stress. These observations revealed that Mfn2 plays an indispensable role in protection against MI-induced injury by Notch1. The mechanism might involve disrupting a damaging cycle of mitochondrial damage and ROS generation. Furthermore, melatonin activated Notch1 signaling and increased Mfn2 expression were reversed by luzindole, a nonselective antagonist of the melatonin receptor. Notably, melatonin attenuated post-MI injury in normal mice, but not in mice deficient in Notch1 or Mfn2. These results demonstrate that melatonin attenuates post-MI injury via the Notch1/Mfn2 pathway in a receptor-dependent manner.

Pathophysiology of ST-segment elevation myocardial infarction: novel mechanisms and treatments

Despite major advances in mechanical and pharmacological reperfusion strategies to improve acute myocardial infarction (MI) injury, substantial mortality, morbidity, and socioeconomic burden still exists. To further reduce infarct size and thus ameliorate clinical outcome, the focus has also shifted towards early detection of MI with high-sensitive troponin assays, imaging, cardioprotection against pathophysiological targets of myocardial reperfusion injury with mechanical (ischaemic post-conditioning, remote ischaemic pre-conditioning, therapeutic hypothermia, and hypoxemia) and newer pharmacological interventions (atrial natriuretic peptide, cyclosporine A, and exenatide). Evidence from animal models of myocardial ischaemia and reperfusion also demonstrated promising results on more selective anti-inflammatory compounds that require additional validation in humans. Cardiac stem cell treatment also hold promise to reduce infarct size and negative remodelling of the left ventricle that may further improves symptoms and prognosis in these patients. This review focuses on the pathophysiology, detection, and reperfusion strategies of ST-segment elevation MI as well as current and future challenges to reduce ischaemia/reperfusion injury and infarct size that may result in a further improved outcome in these patients.

Difference in mobilization of progenitor cells after myocardial infarction in smoking versus non-smoking patients: insights from the BONAMI trial

Introduction

Although autologous bone marrow cell (BMC) therapy has emerged as a promising treatment for acute myocardial infarction (AMI), trials reported mixed results. In the BONAMI trial, active smoking reduced cardiac function recovery after reperfused AMI. Therefore, we hypothesized that variability in the functionality of BMCs retrieved from patients with cardiovascular risk factors may partly explain these mixed results. We investigated the characteristics of progenitor cells in active smokers and non-smokers with AMI and their potential impact on BMC therapy efficacy.

Methods

Bone marrow and blood samples from 54 smoking and 47 non-smoking patients enrolled in the BONAMI cell therapy trial were analyzed.

Results

The white BMC and CD45dimCD34+ cell numbers were higher in active smokers (P = 0.001, P = 0.03, respectively). In marked contrast, either bone marrow or blood endothelial progenitor CD45dimCD34 + KDR + cells (EPCs) were decreased in active smokers (P = 0.005, P = 0.04, respectively). Importantly, a multivariate analysis including cardiovascular risk factors confirmed the association between active smoking and lower EPC number in bone marrow (P = 0.04) and blood (P = 0.04). Furthermore, baseline circulating EPC count predicted infarct size decrease at three months post-AMI in non-smokers (P = 0.01) but not in active smokers. Interestingly, baseline circulating EPCs were no longer predictive of cardiac function improvement in the BMC therapy group.

Conclusions

These data suggest that circulating EPCs play an important role in cardiac repair post-AMI only in non-smokers and that active smoking-associated EPC alterations may participate in the impairment of cardiac function recovery observed in smokers after AMI, an effect that was overridden by BMC therapy.

The challenges of autologous cell therapy: systemic anti-thrombotic therapies interfering with serum coagulation may disable autologous serum-containing cell products for therapeutical use

Cell therapy of acute myocardial infarction (AMI) with bone marrow-derived mononuclear cells (BMC) resulted in a modest improvement of cardiac function, but clinical trial results were heterogeneous. After isolation, BMC are maintained in medium supplemented with complements such as autologous serum to maintain optimal cell viability until administration. In the REPAIR-AMI trial, serum was prepared using tubes containing coagulation accelerators, but the regulatory agency recommended using additive-free tubes for the pivotal BAMI trial. Here, we show that serum obtained from patients with anti-thrombotic therapy in tubes without coagulation accelerators induces clotting, thereby rendering the cell product unsuitable for intra-coronary application. Specifically, systemic treatment of patients with low doses of heparin prevented efficient coagulation ex vivo, and the resulting partially clotted plasma induced cell aggregation within 1-18 h in the cell product. Utmost care has to be taken to test autologous components of cell products before clinical use. The development of media including the appropriate recombinant growth factors for maintaining cell functionality ex vivo may be warranted.

Aerobic interval training attenuates mitochondrial dysfunction in rats post-myocardial infarction: roles of mitochondrial network dynamics

Aerobic interval training (AIT) can favorably affect cardiovascular diseases. However, the effects of AIT on post-myocardial infarction (MI)—associated mitochondrial dysfunctions remain unclear. In this study, we investigated the protective effects of AIT on myocardial mitochondria in post-MI rats by focusing on mitochondrial dynamics (fusion and fission). Mitochondrial respiratory functions (as measured by the respiratory control ratio (RCR) and the ratio of ADP to oxygen consumption (P/O)); complex activities; dynamic proteins (mitofusin (mfn) 1/2, type 1 optic atrophy (OPA1) and dynamin-related protein1 (DRP1)); nuclear peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC-1α); and the oxidative signaling of extracellular signal-regulated kinase (ERK) 1/2, c-Jun NH₂-terminal protein kinase (JNK) and P53 were observed. Post-MI rats exhibited mitochondrial dysfunction and adverse mitochondrial network dynamics (reduced fusion and increased fission), which was associated with activated ERK1/2-JNK-P53 signaling and decreased nuclear PGC-1α. After AIT, MI-associated mitochondrial dysfunction was improved (elevated RCR and P/O and enhanced complex I, III and IV activities); in addition, increased fusion (mfn2 and OPA1), decreased fission (DRP1), elevated nuclear PGC-1α and inactivation of the ERK1/2-JNK-P53 signaling were observed. These data demonstrate that AIT may restore the post-MI mitochondrial function by inhibiting dynamics pathological remodeling, which may be associated with inactivation of ERK1/2-JNK-P53 signaling and increase in nuclear PGC-1α expression.