Specific MicroRNAs comparisons in hypoxia and morphine preconditioning against hypoxia-reoxgenation injury with and without heart failure

Nicotinamide riboside attenuates myocardial ischemia-reperfusion injury via regulating SIRT3/SOD2 signaling pathway

Ischemic heart disease invariably leads to devastating damage to human health. Nicotinamide ribose (NR), as one of the precursors of NAD+ synthesis, has been discovered to exert a protective role in various neurological and cardiovascular disorders. Our findings demonstrated that pretreatment with 200 mg/kg NR for 3 h significantly reduced myocardial infarct area, decreased levels of CK-MB and LDH in serum, and improved cardiac function in the rats during myocardial ischemia-reperfusion (I/R) injury. Meanwhile, 0.5 mM NR also effectively increased the viability and decreased the LDH release of H9c2 cells during OGD/R. We had provided evidence that NR pretreatment could decrease mitochondrial reactive oxygen species (mtROS) production and MDA content, and enhance SOD activity, thereby mitigating mitochondrial damage and inhibiting apoptosis during myocardial I/R injury. Further investigations revealed that NR increased NAD+ content and upregulated SIRT3 protein expression in myocardium. Through using of SIRT3 small interfering RNA and the SIRT3 deacetylase activity inhibitor 3-TYP, we had confirmed that the cardioprotective effect of NR on cardiomyocytes was largely dependent on the inhibition of mitochondrial oxidative stress via SIRT3-SOD2 axis. Overall, our study suggested that exogenous supplementation with NR mitigated mitochondrial damage and inhibited apoptosis during myocardial I/R injury by reducing mitochondrial oxidative stress via SIRT3-SOD2-mtROS pathway.

Morphine Preconditioning Alleviates Ischemia/Reperfusion-induced Caspase-8-dependent Neuronal Apoptosis through cPKCγ-NF-κB-cFLIPL Pathway

BACKGROUND

Perioperative cerebral ischemia/reperfusion injury is a major contributor to postoperative death and cognitive dysfunction in patients. It was reported that morphine preconditioning (MP) can mimic ischemia/hypoxia preconditioning to protect against ischemia/reperfusion injury. However, the mechanism of MP on the ischemia/reperfusion-induced neuronal apoptosis has not been fully clarified.

METHODS

The middle cerebral artery occlusion/reperfusion (MCAO/R) model of mice and the oxygen-glucose deprivation/reoxygenation (OGD/R) model in primary cortical neurons were used to mimic ischemic stroke. In vivo, the infarct size was measured by using TTC staining; NDSS, Longa score system, and beam balance test were performed to evaluate the neurological deficits of mice; the expression of the protein was detected by using a western blot. In vitro, the viability of neurons was determined by using CCK-8 assay; the expression of protein and mRNA were assessed by using western blot, RT-qPCR, and immunofluorescent staining; the level of apoptosis was detected by using TUNEL staining.

RESULTS

MP can improve the neurological functions of mice following MCAO/R (P<0.001, n=10 per group). MP can decrease the infarct size (P<0.001, n=10 per group) and the level of cleaved-caspase-3 of mice following MCAO/R (P<0.01 or 0.001, n=6 per group). MP can increase the levels of cPKCγ membrane translocation, p-p65, and cFLIPL, and decrease the levels of cleaved-caspase-8, 3 in neurons after OGD/R or MCAO/R 1 d (P<0.05, 0.01 or 0.001, n=6 per group). In addition, MP could alleviate OGD/R-induced cell apoptosis (P<0.001, n=6 per group).

CONCLUSION

MP alleviates ischemia/reperfusion-induced Caspase 8-dependent neuronal apoptosis through the cPKCγ-NF-κB-cFLIPL pathway.

Integrated analysis of long non-coding RNAs and mRNAs associated with glaucoma in vitro

INTRODUCTION

In recent years, the biological functions and important roles of long non-coding RNAs (lncRNAs) have been widely reported in many diseases. Although glaucoma is the leading cause of blindness worldwide, the specific mechanisms of lncRNAs in the pathogenesis and progression of glaucoma remain unclear. Our research aims to elucidate the differentially expressed lncRNAs and mRNAs in glaucoma and to provide a basis for further exploration of the specific mechanism of action of lncRNAs in the progression of glaucoma.

METHODS

We performed RNA sequencing on samples from a pressurized model of R28 cells and performed bioinformatics analyses on the sequencing results. The expression consistency of lncRNAs in clinical samples from patients with glaucoma or cataracts was detected using real-time quantitative polymerase chain reaction (RT-qPCR).

RESULTS

RNA sequencing results showed that lncRNAs in cluster 5 were upregulated with increasing stress after typing all significantly altered lncRNAs using k-means in a cellular stress model. KEGG analysis indicated that they were associated with neurodegenerative diseases. Differentially expressed lncRNAs were verified by RT-qPCR, and the lncRNA expression levels of AC120246.2 and XLOC_006247 were significantly higher in the aqueous humor (AH) of patients with glaucoma than in those with cataracts. For LOC102551819, there was almost no expression in the AH and trabecular meshwork in patients with glaucoma but high expression was observed in the iris.

CONCLUSION

Our research proposes potential diagnostic or intervention targets for clinical applications as well as a theoretical basis for more in-depth research on the function of lncRNAs in glaucoma.

Prenatal opioid-exposed infant extracellular miRNA signature obtained at birth predicts severity of neonatal opioid withdrawal syndrome

Prenatal opioid exposure (POE) is commonly associated with neonatal opioid withdrawal syndrome (NOWS), which is characterized by a broad variability in symptoms and severity. Currently there are no diagnostic tools to reliably predict which infants will develop severe NOWS, while risk stratification would allow for proactive decisions about appropriate clinical monitoring and interventions. The aim of this prospective cohort study was to assess if extracellular microRNAs (miRNAs) in umbilical cord plasma of infants with POE could predict NOWS severity. Participants (n = 58) consisted of pregnant women receiving medications for opioid use disorder and their infants. NOWS severity was operationalized as the need for pharmacologic treatment and prolonged hospitalization (≥ 14 days). Cord blood miRNAs were assessed using semi-quantitative qRT-PCR arrays. Receiver operating characteristic curves and area under the curve (AUC) were estimated. The expression of three miRNAs (miR-128-3p, miR-30c-5p, miR-421) predicted need for pharmacologic treatment (AUC: 0.85) and prolonged hospitalization (AUC: 0.90). Predictive validity improved after two miRNAs (let-7d-5p, miR-584-5p) were added to the need for pharmacologic treatment model (AUC: 0.94) and another two miRNAs (let-7b-5p, miR-10-5p) to the prolonged hospitalization model (AUC: 0.99). Infant cord blood extracellular miRNAs can proactively identify opioid-exposed neonates at high-risk for developing severe NOWS.

Identification and Functional Analysis of lncRNAs Responsive to Hypoxia in Eospalax fontanierii

Subterranean rodents could maintain their normal activities in hypoxic environments underground. Eospalax fontanierii, as one kind of subterranean rodent found in China can survive very low oxygen concentration in labs. It has been demonstrated that long non-coding RNAs (lncRNAs) have important roles in gene expression regulations at different levels and some lncRNAs were found as hypoxia-regulated lncRNAs in cancers. We predicted thousands of lncRNAs in the liver and heart tissues by analyzing RNA-Seq data in Eospalax fontanierii. Those lncRNAs often have shorter lengths, lower expression levels, and lower GC contents than mRNAs. Majors of lncRNAs have expression peaks in hypoxia conditions. We found 1128 DE-lncRNAs (differential expressed lncRNAs) responding to hypoxia. To search the miRNA regulation network for lncRNAs, we predicted 471 and 92 DE-lncRNAs acting as potential miRNA target and target mimics, respectively. We also predicted the functions of DE-lncRNAs based on the co-expression networks of lncRNA-mRNA. The DE-lncRNAs participated in the functions of biological regulation, signaling, development, oxoacid metabolic process, lipid metabolic/biosynthetic process, and catalytic activity. As the first study of lncRNAs in Eospalax fontanierii, our results show that lncRNAs are popular in transcriptome widely and can participate in multiple biological processes in hypoxia responses.

MicroRNA expression profiling involved in doxorubicin-induced cardiotoxicity using high-throughput deep-sequencing analysis

MicroRNAs (miRNAs/miRs) are sensitive biomarkers and endogenous repressors of gene expression by decreasing mRNA stability and interfering with mRNA translation. Despite a number of investigations revealing the dysregulation of miRNA expression associated with cardiotoxicity induced by doxorubicin (Dox), perturbation of miRNAs directly resulting from Dox at early stage in cardiomyocytes and the target gene interaction remain largely unknown. In the present study, high-throughput deep-sequencing was used to analyze changes in global miRNA expression in H9c2 cardiomyocytes exposed to 5 µg/ml Dox for 0, 12 or 24 h. Compared with the 0-h time point, the expression levels of 386 unique miRNAs were altered. Based on miRNA expression and fold-change, the target genes of 76 selected miRNAs were further analyzed using gene interaction networks and pathway enrichment analysis. These miRNAs were involved in the regulation of different pathways, whose functions included apoptosis, cell proliferation, extracellular matrix remodeling, oxidative stress and lipid metabolism. These differentially expressed miRNAs included let-7 family, miR-29b-3p, miR-378-3/5p, miR-351-3p, miR-664-3p, miR-455-3p, miR-298-3p, miR-702-5p, miR-128-1-5p, miR-671 and miR-421-5p. The present data indicated that global wide miRNA profiling in Dox-induced cardiomyocytes may provide a novel mechanistic insight into understanding Dox-induced heart failure and cardiotoxicity, as well as novel biomarkers and therapeutic targets.

Morphine and myocardial ischaemia-reperfusion

Coronary heart disease (CHD) is a cardiovascular disease with high mortality and disability worldwide. The main pathological manifestation of CHD is myocardial injury due to ischaemia-reperfusion, resulting in the death of cardiomyocytes (apoptosis and necrosis) and the occurrence of cardiac failure. Morphine is a nonselective opioid receptor agonist that has been commonly used for analgesia and to treat ischaemic heart disease. The present review focused on morphine-induced protection in an animal model of myocardial ischaemia-reperfusion and chronic heart failure and the effects of morphine on ST segment elevation myocardial infarction (STEMI) patients who underwent pre-primary percutaneous coronary intervention (pre-PPCI) or PPCI. The signalling pathways involved are also briefly described.

What is considered cardiotoxicity of anthracyclines in animal studies

Anthracyclines are commonly used anticancer drugs with well-known and extensively studied cardiotoxic effects in humans. In the clinical setting guidelines for assessing cardiotoxicity are well-established with important therapeutic implications. Cardiotoxicity in terms of impairment of cardiac function is largely diagnosed by echocardiography and based on objective metrics of cardiac function. Until this day, cardiotoxicity is not an endpoint in the current general toxicology and safety pharmacology preclinical studies, although other classes of drugs apart from anthracyclines, along with everyday chemicals have been shown to manifest cardiotoxic properties. Also, in the relevant literature there are not well-established objective criteria or reference values in order to uniformly characterize cardiotoxic adverse effects in animal models. This in depth review focuses on the evaluation of two important echocardiographic indices, namely ejection fraction and fractional shortening, in the literature concerning anthracycline administration to rats as the reference laboratory animal model. The analysis of the gathered data gives promising results and solid prospects for both, defining anthracycline cardiotoxicity objective values and delineating the guidelines for assessing cardiotoxicity as a separate hazard class in animal preclinical studies for regulatory purposes.

LncRNA 1700020I14Rik/miR-297a/CGRP axis suppresses myocardial cell apoptosis in myocardial ischemia-reperfusion injury

BACKGROUND

Long non-coding RNAs (lncRNAs) are closely related to various human diseases, but their role in myocardial injury has not been fully elucidated. In the current study, we found that the expression of lncRNA 1700020I14Rik was significantly down-regulated in myocardial injury tissues and the underlying mechanism by which lncRNA 1700020I14Rik regulated myocardial cell injury was investigated.

METHODS

The model of myocardial ischemia-reperfusion (I/R) injury and myocardial cells hypoxia/reoxygenation (H/R) injury were established and the expression of 1700020I14Rik, miR-297a or CGRP was analyzed by qRT-PCR or Western blot. Moreover, myocardial cell apoptosis was assessed by TUNEL staining and the concentration of LDH in the mouse plasma sample or myocardial cell culture supernatant was measured by the LDH cytotoxicity test kit. Furthermore, the differences of myocardial cell survival rate after H/R treatment were assessed by MTT assay and the observation of CGRP expression was performed in HL-1 cells overexpressed or silenced with 1700020I14Rik or miR-297a. In addition, the regulating function of miR-297a on 1700020I14Rik and CGRP expression was analyzed by a dual luciferase reporter assay.

RESULTS

The expressions of 1700020I14Rik and CGRP were abnormally down-regulated in a model of myocardial I/R injury and myocardial cells H/R injury, while miR-297a was up-regulated. By TUNEL staining, the apoptotic rate of myocardial cells in the model of myocardial I/R injury was significantly increased. Furthermore, the concentrations of LDH in the mouse plasma sample or myocardial cell culture supernatant were significantly increased after myocardial cell injury. By MTT assay, the survival rate of cells was decreased after myocardial cells were treated with H/R. In addition, overexpression of 1700020I14Rik or knockdown of miR-297a could up-regulate CGRP protein level, while interference with 1700020I14Rik or overexpression of miR-297a produced the opposite result. Further study confirmed that lncRNA 1700020I14Rik/miR-297a/CGRP axis suppressed myocardial cell apoptosis in myocardial I/R injury.

CONCLUSION

Our results indicated that 1700020I14Rik was abnormally down-regulated in myocardial injury tissues. In-depth studies manifested that 1700020I14Rik/miR-297a/CGRP axis suppressed myocardial cell apoptosis in myocardial I/R injury.

MiRNA-Mediated Mechanisms of Cardiac Protection in Ischemic and Remote Ischemic Preconditioning-A Qualitative Systematic Review

BACKGROUND

Ischemic preconditioning (IPC) and remote ischemic preconditioning (RIPC) protect myocardial tissue against subsequent ischemia and reperfusion injury (IRI) and have a high potential to improve patient outcome. The mediators and mechanisms of protection through IPC and RIPC remain largely unknown, but micro-RNAs (miRNAs) are promising candidates.

METHODS

Systematic review of Medline and Embase databases for biomedical scientific literature.

RESULTS

A total of 26 relevant publications (21 full-text original articles and 5 conference abstracts) were identified, 8 describing cell culture experiments, 14 animal experiments, and 4 randomized clinical trials in humans. Most commonly reported miRNAs with differential expression between preconditioned and control groups include miR-1, miR-21, and miR-144. Experimental designs and procedures differ widely, thereby limiting the potential to compare results between studies. Two of the four RCTs did not find any differentially expressed miRNAs.

CONCLUSIONS

Results from RCTs should feed back into basic research and focused studies confirming or rejecting hypotheses generated by these RCTs are needed.

Endogenous opiates and behavior: 2017

This paper is the fortieth consecutive installment of the annual anthological review of research concerning the endogenous opioid system, summarizing articles published during 2017 that studied the behavioral effects of molecular, pharmacological and genetic manipulation of opioid peptides and receptors as well as effects of opioid/opiate agonists and antagonists. The review is subdivided into the following specific topics: molecular-biochemical effects and neurochemical localization studies of endogenous opioids and their receptors (1), the roles of these opioid peptides and receptors in pain and analgesia in animals (2) and humans (3), opioid-sensitive and opioid-insensitive effects of nonopioid analgesics (4), opioid peptide and receptor involvement in tolerance and dependence (5), stress and social status (6), learning and memory (7), eating and drinking (8), drug abuse and alcohol (9), sexual activity and hormones, pregnancy, development and endocrinology (10), mental illness and mood (11), seizures and neurologic disorders (12), electrical-related activity and neurophysiology (13), general activity and locomotion (14), gastrointestinal, renal and hepatic functions (15), cardiovascular responses (16), respiration and thermoregulation (17), and immunological responses (18).

The inhibition of apoptosis through myocardial postconditioning by affecting Fas/FasIg signaling through miR139-3p and miR181a-1

BACKGROUND AND AIM OF THE STUDY

Ischemic postconditioning (PostC) is considered to be one of the strongest mechanisms limiting the extent of myocardial infarction, and reducing ischemia-reperfusion (I/R) injury. I/R-induced myocardial injury results in apoptosis, autophagy, and necrosis. The aim of the present study was to investigate the roles of the necrotic gene cytochrome b-245 beta chain (Cybb); Cybb-related microRNA miR139-3p; the autophagy gene Beclin-1 (Becn1); proapoptotic genes Fas, Faslg and growth arrest and DNA-damage-inducible 45 alpha (Gadd45a); and apoptosis-related microRNA miR181a-1 levels on I/R injury, as well as, the potential protective effects of PostC through this gene and microRNAs.

METHODS

The left main coronary artery was subjected to ischemia for 30 minutes, followed by reperfusion for 120 minutes. PostC involved three cycles of I/R, each lasting 10 seconds. Gene and microRNA levels were analyzed using a quantitative reverse transcription-polymerase chain reaction.

RESULTS

Although an increase was observed in the expression levels of the Cybb, Fas, Faslg and Gadd45a genes, the miR139-3p, miR181a-1, and Becn1 expression levels were found to decrease with I/R injury. PostC was determined to restore the expression of all the genes to the normal levels.

CONCLUSIONS

The abovementioned genes can be used as important prognostic markers in the diagnosis of reperfusion injury and in the evaluation of treatment efficacy. It was further noted that increased expression of CYBB, which is one of the target genes for miR139-3p, and a decreased expression of miR181a-1 may cause apoptosis by affecting Fas and Faslg signaling. PostC can inhibit apoptosis by increasing miR139-3p and miR181a-1 levels.

Novel Roles of Non-Coding RNAs in Opioid Signaling and Cardioprotection

Cardiovascular disease (CVD) is a significant cause of morbidity and mortality across the world. A large proportion of CVD deaths are secondary to coronary artery disease (CAD) and myocardial infarction (MI). Even though prevention is the best strategy to reduce risk factors associated with MI, the use of cardioprotective interventions aimed at improving patient outcomes is of great interest. Opioid conditioning has been shown to be effective in reducing myocardial ischemia-reperfusion injury (IRI) and cardiomyocyte death. However, the molecular mechanisms behind these effects are under investigation and could provide the basis for the development of novel therapeutic approaches in the treatment of CVD. Non-coding RNAs (ncRNAs), which are functional RNA molecules that do not translate into proteins, are critical modulators of cardiac gene expression during heart development and disease. Moreover, ncRNAs such as microRNAs (miRNAs) and long non-coding RNAs (lncRNAs) are known to be induced by opioid receptor activation and regulate opioid signaling pathways. Recent advances in experimental and computational tools have accelerated the discovery and functional characterization of ncRNAs. In this study, we review the current understanding of the role of ncRNAs in opioid signaling and opioid-induced cardioprotection.

miR‑133b‑5p contributes to hypoxic preconditioning‑mediated cardioprotection by inhibiting the activation of caspase‑8 and caspase-3 in cardiomyocytes

In a previous study using a microRNA (miRNA/miR) microarray assay, we demonstrated that miR-133b-5p was upregulated in response to hypoxic preconditioning (HPC). The present study was designed to investigate the role of the miR‑133b‑5p in HPC‑induced cardioprotection and the underlying mechanisms involving caspase‑8 and caspase‑3 apoptotic signaling. Adult rats were subjected to myocardial ischemia/reperfusion (I/R) injury with or without ischemic preconditioning (IPC), and the level of miR‑133b‑5p in myocardium was measured. Neonatal rat cardiomyocytes were isolated and subjected to hypoxia/reoxygenation (H/R) injury, with or without HPC. miR‑133b‑5p antagomir was transfected into the cardiomyocytes to observe whether it could block HPC‑induced cardioprotection. Cellular injury was evaluated by detecting cell viability, lactate dehydrogenase (LDH) activity and apoptotic rate. Reverse transcription‑quantitative polymerase chain reaction was used to measure the level of miR‑133b‑5p. The activation of caspase‑8 and caspase‑3 were measured by western blot analysis to detect the cleaved fragments as well as a colorimetric assay. Following myocardial I/R injury, the expression of miR‑133b‑5p was decreased in myocardium, while this decrease was restored by IPC. HPC protected neonatal rat cardiomyocytes against H/R injury by increasing cell viability, while reducing LDH release and cell apoptosis. These protective effects were coupled with the upregulation of miR‑133b‑5p. However, the knockdown of miR‑133b‑5p in the cardiomyocytes blocked HPC‑mediated cardioprotection as reflected by the aggravation of cell injury and apoptosis. HPC upregulated miR‑133b‑5p level was markedly suppressed by the antagomir. In addition, the cleavage and activities of caspase‑8 and caspase‑3 were inhibited by HPC while reversed by knockdown of miR‑133b‑5p. Upregulation of miR‑133b‑5p contributes to HPC‑mediated cardioprotection in cardiomyocytes, and the mechanism may be associated with inhibition of caspase‑8 and caspase‑3 apoptotic signaling.

Differential microRNA expression in human placentas of term intra-uterine growth restriction that regulates target genes mediating angiogenesis and amino acid transport

Placental insufficiency leading to intrauterine growth restriction (IUGR) demonstrates perturbed gene expression affecting placental angiogenesis and nutrient transfer from mother to fetus. To understand the post-transcriptional mechanisms underlying such placental gene expression changes, our objective was to identify key non-coding microRNAs that express biological function. To this end, we initially undertook microarrays targeting microRNAs in a small sub-set of placentas of appropriate (AGA) versus small for gestational age (SGA) weight infants, and observed up-regulation of 97 miRs and down-regulation of 44 miRs in SGA versus AGA. In a larger cohort of samples (AGA, n = 21; SGA, n = 11; IUGR subset, n = 5), we validated by qRT-PCR differential expression of three specific microRNAs (miR-10b, -363 and -149) that target genes mediating angiogenesis and nutrient transfer. Validation yielded an increase in miR-10b and -363 expression of ~2.5-fold (p<0.02 each) in SGA versus AGA, and of ~3-fold (p<0.005) in IUGR versus AGA, with no significant change despite a trending increase in miR-149. To further establish a cause-and-effect paradigm, employing human HTR8 trophoblast cells, we assessed the effect of nutrient deprivation on miR expression and inhibition of endogenous miRs on target gene expression. In-vitro nutrient deprivation (~50%) increased the expression of miR-10b and miR-149 by 1.5-fold (p<0.02) while decreasing miR-363 (p<0.0001). Inhibition of endogenous miRs employing antisense sequences against miR-10b, -363 and -149 revealed an increase respectively in the expression of the target genes KLF-4 (transcription factor which regulates angiogenesis), SNAT1 and 2 (sodium coupled neutral amino acid transporters) and LAT2 (leucine amino acid transporter), which translated into a similar change in the corresponding proteins. Finally to establish functional significance we performed dual-luciferase reporter assays with 3'-insertion of miR-10b alone and observed a ~10% reduction in the 5'-luciferase activity versus the control. Lastly, we further validated by microarray and employing MirWalk software that the pathways and target genes identified by differentially expressed miRs in SGA/IUGR compared to AGA are consistent in a larger cohort. We have established the biological significance of various miRs that target common transcripts mediating pathways of importance, which are perturbed in the human IUGR placenta.