IL-1 receptor regulates microRNA-135b expression in a negative feedback mechanism during cigarette smoke-induced inflammation

MicroRNAs: Key modulators of inflammation-associated diseases

Inflammation is a multifaceted biological and pathophysiological response to injuries, infections, toxins, and inflammatory mechanisms that plays a central role in the progression of various diseases. MicroRNAs (miRNAs) are tiny, 19-25 nucleotides long, non-coding RNAs that regulate gene expression via post-transcriptional repression. In this review, we highlight the recent findings related to the significant roles of miRNAs in regulating various inflammatory cascades and immunological processes in the context of many lifestyle-related diseases such as diabetes, cardiovascular diseases, cancer, etc. We also converse on how miRNAs can have a dual impact on inflammatory responses, suggesting that regulation of their functions for therapeutic purposes may be disease-specific.

Animal models and mechanisms of tobacco smoke-induced chronic obstructive pulmonary disease (COPD)

Chronic obstructive pulmonary disease (COPD) is the third leading cause of death worldwide, and its global health burden is increasing. COPD is characterized by emphysema, mucus hypersecretion, and persistent lung inflammation, and clinically by chronic airflow obstruction and symptoms of dyspnea, cough, and fatigue in patients. A cluster of pathologies including chronic bronchitis, emphysema, asthma, and cardiovascular disease in the form of hypertension and atherosclerosis variably coexist in COPD patients. Underlying causes for COPD include primarily tobacco use but may also be driven by exposure to air pollutants, biomass burning, and workplace related fumes and chemicals. While no single animal model might mimic all features of human COPD, a wide variety of published models have collectively helped to improve our understanding of disease processes involved in the genesis and persistence of COPD. In this review, the pathogenesis and associated risk factors of COPD are examined in different mammalian models of the disease. Each animal model included in this review is exclusively created by tobacco smoke (TS) exposure. As animal models continue to aid in defining the pathobiological mechanisms of and possible novel therapeutic interventions for COPD, the advantages and disadvantages of each animal model are discussed.

Possible therapeutic targets for NLRP3 inflammasome-induced breast cancer

Inflammation plays a major role in the development and progression of breast cancer(BC). Proliferation, invasion, angiogenesis, and metastasis are all linked to inflammation and tumorigenesis. Furthermore, tumor microenvironment (TME) inflammation-mediated cytokine releases play a critical role in these processes. By recruiting caspase-1 through an adaptor apoptosis-related spot protein, inflammatory caspases are activated by the triggering of pattern recognition receptors on the surface of immune cells. Toll-like receptors, NOD-like receptors, and melanoma-like receptors are not triggered. It activates the proinflammatory cytokines interleukin (IL)-1β and IL-18 and is involved in different biological processes that exert their effects. The Nod-Like Receptor Protein 3 (NLRP3) inflammasome regulates inflammation by mediating the secretion of proinflammatory cytokines and interacting with other cellular compartments through the inflammasome's central role in innate immunity. NLRP3 inflammasome activation mechanisms have received much attention in recent years. Inflammatory diseases including enteritis, tumors, gout, neurodegenerative diseases, diabetes, and obesity are associated with abnormal activation of the NLRP3 inflammasome. Different cancer diseases have been linked to NLRP3 and its role in tumorigenesis may be the opposite. Tumors can be suppressed by it, as has been seen primarily in the context of colorectal cancer associated with colitis. However, cancers such as gastric and skin can also be promoted by it. The inflammasome NLRP3 is associated with breast cancer, but there are few specific reviews. This review focuses on the structure, biological characteristics and mechanism of inflammasome, the relationship between NLRP3 in breast cancer Non-Coding RNAs, MicroRNAs and breast cancer microenvironment, especially the role of NLRP3 in triple-negative breast cancer (TNBC). And the potential strategies of using NLRP3 inflammasome to target breast cancer, such as NLRP3-based nanoparticle technology and gene target therapy, are reviewed.

Association of nanoparticles and Nrf2 with various oxidative stress-mediated diseases

Nuclear factor erythroid 2-related factor 2 (Nrf2) is a transcription factor that regultes the cellular antioxidant defense system at the posttranscriptional level. During oxidative stress, Nrf2 is released from its negative regulator Kelch-like ECH-associated protein 1 (Keap1) and binds to antioxidant response element (ARE) to transcribe antioxidative metabolizing/detoxifying genes. Various transcription factors like aryl hydrocarbon receptor (AhR) and nuclear factor kappa light chain enhancer of activated B cells (NF-kB) and epigenetic modification including DNA methylation and histone methylation might also regulate the expression of Nrf2. Despite its protective role, Keap1/Nrf2/ARE signaling is considered as a pharmacological target due to its involvement in various pathophysiological conditions such as diabetes, cardiovascular disease, cancer, neurodegenerative diseases, hepatotoxicity and kidney disorders. Recently, nanomaterials have received a lot of attention due to their unique physiochemical properties and are also used in various biological applications, for example, biosensors, drug delivery systems, cancer therapy, etc. In this review, we will be discussing the functions of nanoparticles and Nrf2 as a combined therapy or sensitizing agent and their significance in various diseases such as diabetes, cancer and oxidative stress-mediated diseases.

The Role of Epicardial Adipose Tissue-Derived MicroRNAs in the Regulation of Cardiovascular Disease: A Narrative Review

Cardiovascular diseases have been leading cause of death worldwide for many decades, and obesity has been acknowledged as a risk factor for cardiovascular diseases. In the present review, human epicardial adipose tissue-derived miRNAs reported to be differentially expressed under pathologic conditions are discussed and summarized. The results of the literature review indicate that some of the epicardial adipose tissue-derived miRNAs are believed to be cardioprotective, while some others show quite the opposite effects depending on the underlying pathologic conditions. Furthermore, they suggest that that the epicardial adipose tissue-derived miRNAs have great potential as both a diagnostic and therapeutic modality. Nevertheless, mainly due to highly limited availability of human samples, it is very difficult to make any generalized claims on a given miRNA in terms of its overall impact on the cardiovascular system. Therefore, further functional investigation of a given miRNA including, but not limited to, the study of its dose effect, off-target effects, and potential toxicity is required. We hope that this review can provide novel insights to transform our current knowledge on epicardial adipose tissue-derived miRNAs into clinically viable therapeutic strategies for preventing and treating cardiovascular diseases.

Regulation of Inflammasome by microRNAs in Triple-Negative Breast Cancer: New Opportunities for Therapy

During the past decade, researchers have investigated the molecular mechanisms of breast cancer initiation and progression, especially triple-negative breast cancer (TNBC), in order to identify specific biomarkers that could serve as feasible targets for innovative therapeutic strategies development. TNBC is characterized by a dynamic and aggressive nature, due to the absence of estrogen, progesterone and human epidermal growth factor 2 receptors. TNBC progression is associated with the dysregulation of nucleotide-binding oligomerization domain-like receptor and pyrin domain-containing protein 3 (NLRP3) inflammasome, followed by the release of pro-inflammatory cytokines and caspase-1 dependent cell death, termed pyroptosis. The heterogeneity of the breast tumor microenvironment triggers the interest of non-coding RNAs' involvement in NLRP3 inflammasome assembly, TNBC progression and metastasis. Non-coding RNAs are paramount regulators of carcinogenesis and inflammasome pathways, which could help in the development of efficient treatments. This review aims to highlight the contribution of non-coding RNAs that support inflammasome activation and TNBC progression, pointing up their potential for clinical applications as biomarkers for diagnosis and therapy.

Comparison of effects of tobacco cigarettes, electronic nicotine delivery systems and tobacco heating products on miRNA-mediated gene expression. A systematic review

OBJECTIVES

This work attempts to summarize current knowledge on the effects of cigarettes, electronic nicotine delivery systems and tobacco heating products on miRNA-mediated gene expression regulation and on their possible impact on smoking-related respiratory disease development.

MATERIALS AND METHODS

Literature search by terms combination: 'smoking', 'cigarette' 'THP', 'tobacco heating product', 'ENDS', 'electronic nicotine delivery system', 'e-cigarette', electronic cigarette' and 'miRNA-mediated gene expression' has been performed from October 2021 to February 2022. In this systematic review all relevant literature, including clinical trials, cellular and animal-based studies were included.

RESULTS

Cigarette smoke (CS) significantly altered transcriptome, including miRNAs expression profile. MiRNA-mediated gene expression is mentioned as one of the mechanisms associated with smoking-related respiratory disease development. Differential expression of miRNAs was reduced in aerosol from e-cigarettes (EC) and tobacco heating products (THP) when compared to CS. However, there was a significant alteration of some miRNAs expression when compared to air-controls in both EC and THP.

DISCUSSION

CS negatively affects transcriptome and miRNA-mediated gene expression regulation because of a huge number of hazardous substances which predispose to smoking-related diseases. Despite the reduced effect of ENDS and THP on miRNAs profile compared to CS, differences in expression of miRNAs when compared to air-control were observed, which may be harmful to never-smokers who may perceive such alternative smoking products as non-hazardous. To clearly indicate the role of ENDS and THP in the alteration of miRNA-mediated gene expression and the development of smoking-related respiratory diseases associated with this mechanism, more long-term studies should be performed in the future.

Genetic architecture of microRNA expression and its link to complex diseases in the Japanese population

Understanding the genetic effects on non-coding RNA (ncRNA) expression facilitates functional characterization of disease-associated genetic loci. Among several classes of ncRNAs, microRNAs (miRNAs) are key post-transcriptional gene regulators. Despite its biological importance, previous studies on the genetic architecture of miRNA expression focused mostly on the European individuals, underrepresented in other populations. Here, we mapped miRNA expression quantitative trait loci (miRNA-eQTL) for 343 miRNAs in 141 Japanese using small RNA sequencing (sRNA-seq) and whole-genome sequencing (WGS), identifying 1275 cis-miRNA-eQTL variants for 40 miRNAs (false discovery rate < 0.2). Of these, 25 miRNAs having eQTL were unreported in the European studies, including 5 miRNAs with their lead variant monomorphic in the European populations, which demonstrates the value of miRNA-eQTL analysis in diverse ancestral populations. MiRNAs with eQTL effect showed allele-specific expression (ASE) (e.g. miR-146a-3p), and ASE analysis further detected cis-regulatory variants not captured by the conventional miRNA-eQTL mapping (e.g. miR-933). We identified a copy number variation (CNV) associated with miRNA expression (e.g. miR-570-3p, P = 7.2 × 10-6), which contributes to a more comprehensive landscape of miRNA-eQTLs. To elucidate a post-transcriptional modification in miRNAs, we created a catalog of miRNA-editing sites, including ten canonical and six non-canonical sites. Finally, by integrating the miRNA-eQTLs and Japanese genome-wide association studies of 25 complex traits (mean n = 192 833), we conducted a transcriptome-wide association study (TWAS), identifying miR-1908-5p as a potential mediator for adult height, colorectal cancer, and type 2 diabetes (P < 9.1 × 10-5). Our study broadens the population diversity in ncRNA-eQTL studies and contributes to functional annotation of disease-associated loci found in non-European populations.

Role of Non-Coding RNAs in Post-Transcriptional Regulation of Lung Diseases

Non-coding RNAs (ncRNAs), notably microRNAs (miRNAs) and long noncoding RNAs (lncRNAs), have recently gained increasing consideration because of their versatile role as key regulators of gene expression. They adopt diverse mechanisms to regulate transcription and translation, and thereby, the function of the protein, which is associated with several major biological processes. For example, proliferation, differentiation, apoptosis, and metabolic pathways demand fine-tuning for the precise development of a specific tissue or organ. The deregulation of ncRNA expression is concomitant with multiple diseases, including lung diseases. This review highlights recent advances in the post-transcriptional regulation of miRNAs and lncRNAs in lung diseases such as asthma, chronic obstructive pulmonary disease, cystic fibrosis, and idiopathic pulmonary fibrosis. Further, we also discuss the emerging role of ncRNAs as biomarkers as well as therapeutic targets for lung diseases. However, more investigations are required to explore miRNAs and lncRNAs interaction, and their function in the regulation of mRNA expression. Understanding these mechanisms might lead to early diagnosis and the development of novel therapeutics for lung diseases.

Aberrant Post-Transcriptional Regulation of Protein Expression in the Development of Chronic Obstructive Pulmonary Disease

Chronic obstructive pulmonary disease (COPD) is an incurable and prevalent respiratory disorder that is characterized by chronic inflammation and emphysema. COPD is primarily caused by cigarette smoke (CS). CS alters numerous cellular processes, including the post-transcriptional regulation of mRNAs. The identification of RNA-binding proteins (RBPs), microRNAs (miRNAs), and long non-coding RNAs (lncRNAs) as main factors engaged in the regulation of RNA biology opens the door to understanding their role in coordinating physiological cellular processes. Dysregulation of post-transcriptional regulation by foreign particles in CS may lead to the development of diseases such as COPD. Here we review current knowledge about post-transcriptional events that may be involved in the pathogenesis of COPD.

The Potential Roles of Exosomes in Chronic Obstructive Pulmonary Disease

Currently, chronic obstructive pulmonary disease (COPD) is one of the most common chronic lung diseases. Chronic obstructive pulmonary disease is characterized by progressive loss of lung function due to chronic inflammatory responses in the lungs caused by repeated exposure to harmful environmental stimuli. Chronic obstructive pulmonary disease is a persistent disease, with an estimated 384 million people worldwide living with COPD. It is listed as the third leading cause of death. Exosomes contain various components, such as lipids, microRNAs (miRNAs), long non-coding RNAs(lncRNAs), and proteins. They are essential mediators of intercellular communication and can regulate the biological properties of target cells. With the deepening of exosome research, it is found that exosomes are strictly related to the occurrence and development of COPD. Therefore, this review aims to highlight the unique role of immune-cell-derived exosomes in disease through complex interactions and their potentials as potential biomarkers new types of COPD.

Nanoparticle delivery of microRNA-146a regulates mechanotransduction in lung macrophages and mitigates injury during mechanical ventilation

Mechanical ventilation generates injurious forces that exacerbate lung injury. These forces disrupt lung barrier integrity, trigger proinflammatory mediator release, and differentially regulate genes and non-coding oligonucleotides including microRNAs. In this study, we identify miR-146a as a mechanosensitive microRNA in alveolar macrophages that has therapeutic potential to mitigate lung injury during mechanical ventilation. We use humanized in-vitro systems, mouse models, and biospecimens from patients to elucidate the expression dynamics of miR-146a needed to decrease lung injury during mechanical ventilation. We find that the endogenous increase in miR-146a following injurious ventilation is not sufficient to prevent lung injury. However, when miR-146a is highly overexpressed using a nanoparticle delivery platform it is sufficient to prevent injury. These data indicate that the endogenous increase in microRNA-146a during mechanical ventilation is a compensatory response that partially limits injury and that nanoparticle delivery of miR-146a is an effective strategy for mitigating lung injury during mechanical ventilation.

MicroRNAs as Potential Regulators of Immune Response Networks in Asthma and Chronic Obstructive Pulmonary Disease

Chronic respiratory diseases (CRDs) are an important factor of morbidity and mortality, accounting for approximately 6% of total deaths worldwide. The main CRDs are asthma and chronic obstructive pulmonary disease (COPD). These complex diseases have different triggers including allergens, pollutants, tobacco smoke, and other risk factors. It is important to highlight that although CRDs are incurable, various forms of treatment improve shortness of breath and quality of life. The search for tools that can ensure accurate diagnosis and treatment is crucial. MicroRNAs (miRNAs) are small non-coding RNAs and have been described as promising diagnostic and therapeutic biomarkers for CRDs. They are implicated in multiple processes of asthma and COPD, regulating pathways associated with inflammation, thereby showing that miRNAs are critical regulators of the immune response. Indeed, miRNAs have been found to be deregulated in several biofluids (sputum, bronchoalveolar lavage, and serum) and in both structural lung and immune cells of patients in comparison to healthy subjects, showing their potential role as biomarkers. Also, miRNAs play a part in the development or termination of histopathological changes and comorbidities, revealing the complexity of miRNA regulation and opening up new treatment possibilities. Finally, miRNAs have been proposed as prognostic tools in response to both conventional and biologic treatments for asthma or COPD, and miRNA-based treatment has emerged as a potential approach for clinical intervention in these respiratory diseases; however, this field is still in development. The present review applies a systems biology approach to the understanding of miRNA regulatory networks in asthma and COPD, summarizing their roles in pathophysiology, diagnosis, and treatment.

Opposite effects of smoking and nicotine intake on cognition

Our main purpose was to investigate how smoking and nicotine interacted with specific aspects of cognitive functioning. The research was conducted in two parts: (i) an investigation of cognition in heavy smokers and healthy nonsmokers, and (ii) an investigation of cognition in healthy nonsmokers enrolled in a clinical trial involving administration of nicotine gum. Results indicated that the relationship between smoking and nicotine was characterized by an inverted U-shaped effect. On the one hand, cognitive test performance of the heavy smokers group was reduced on all of the cognitive tasks used here. On the other hand, healthy nonsmokers who used 2-mg of nicotine gum performed better, whilst the 4-mg group performed worse than the 2-mg and the placebo group. Demographic data were not related to the cognitive tasks. These data suggest that small doses of nicotine can have an activating function that leads to improved cognition, while heavy smoking on a chronic (and possibly acute) basis leads to cognitive impairment.

Effects of Nicotine Gum Administration on Vision (ENIGMA-Vis): Study Protocol of a Double-Blind, Randomized, and Controlled Clinical Trial

Studies reported that tobacco addiction was related to visual impairments, but one unresolved issue is whether the impairments are related to the many compounds existing in the cigarettes or to the effects of nicotine. On the other hand, nicotine gum can be used as replacement therapy or as a neuroprotective agent for some diseases. The main purpose of this controlled trial is to investigate the effects of nicotine gum on vision. The ENIGMA-Vis trial aims to compare two dosages of nicotine gum (2 and 4 mg) and a placebo gum in a randomized, double-blind, placebo-controlled trial of 100 participants to be allocated into a single group assignment of repeated measures (two studies; N = 50 for each one). Eligibility criteria are healthy non-smokers not diagnosed with substance abuse and without an acute or chronic medical condition. Intervention will last three sessions for each participant with a window frame of 1 week per session. Study outcomes are (1) short-term effects of nicotine gum on contrast sensitivity; (2) short-term effects of nicotine gum on chromatic contrast discrimination; and (3) whether demographics, body mass index, or serum cotinine predicts response of visual processing. This study addresses an important gap in the effects of nicotine on vision. One of the main takeaways of this study is to understand the effects of nicotine on contrast sensitivity and chromatic contrast discrimination. This information will provide a further understanding of how nicotine interacts with early visual processes and help determine how the different components present during smoking can affect vision.

Clinical Trial Registration Number: RBR-46tjy3.

Small RNAs, Big Diseases

The past two decades have seen extensive research done to pinpoint the role of microRNAs (miRNAs) that have led to discovering thousands of miRNAs in humans. It is not, therefore, surprising to see many of them implicated in a number of common as well as rare human diseases. In this review article, we summarize the progress in our understanding of miRNA-related research in conjunction with different types of cancers and neurodegenerative diseases, as well as their potential in generating more reliable diagnostic and therapeutic approaches.

The role of cigarette smoke-induced epigenetic alterations in inflammation

Background

Exposure to cigarette smoke (CS) is a major threat to human health worldwide. It is well established that smoking increases the risk of respiratory diseases, cardiovascular diseases and different forms of cancer, including lung, liver, and colon. CS-triggered inflammation is considered to play a central role in various pathologies by a mechanism that stimulates the release of pro-inflammatory cytokines. During this process, epigenetic alterations are known to play important roles in the specificity and duration of gene transcription.

Main text

Epigenetic alterations include three major modifications: DNA modifications via methylation; various posttranslational modifications of histones, namely, methylation, acetylation, phosphorylation, and ubiquitination; and non-coding RNA sequences. These modifications work in concert to regulate gene transcription in a heritable fashion. The enzymes that regulate these epigenetic modifications can be activated by smoking, which further mediates the expression of multiple inflammatory genes. In this review, we summarize the current knowledge on the epigenetic alterations triggered by CS and assess how such alterations may affect smoking-mediated inflammatory responses.

Conclusion

The recognition of the molecular mechanisms of the epigenetic changes in abnormal inflammation is expected to contribute to the understanding of the pathophysiology of CS-related diseases such that novel epigenetic therapies may be identified in the near future.

Cigarette Smoke Exposure to Pig Larynx in an Inhalation Chamber

OBJECTIVES

This study investigated the effects of cigarette smoke exposure on the pig larynx using an inhalation chamber. Specifically, we compared the effects of cigarette smoke exposure from either 3 cigarettes per day (3cd) or 15 cigarettes per day (15cd) for 20 days.

STUDY DESIGN

In vivo prospective design.

METHODS

Female pigs were exposed via an inhalation chamber to cigarette smoke (3R4F research cigarettes) from 3cd (n = 6) or 15cd (n = 6) for 20 days. Outcomes included histopathology of vocal fold and airway tissues; gene expression of interleukins, TNF-α, and VEGF; protein levels of TNF-α and IL-6; and number of coughs recorded in the chamber.

RESULTS

Pigs exposed to cigarette smoke from 15cd exhibited mild vocal fold edema as compared to the 3cd group on histopathological evaluation. There was also minimal inflammation of nasal and tracheal tissue characterized by presence of more granulocytes in the 15cd group compared to the 3cd group. Cough frequency was significantly greater for the 15cd group compared to the 3cd group.

CONCLUSIONS

A custom-designed large animal inhalation chamber successfully challenged pigs repeatedly, to varying levels of cigarette smoke. Future studies will combine such low levels of smoke exposure with other common challenges such as acid reflux to understand the multifactorial causation of laryngeal pathologies.

Integrative analysis reveals disrupted pathways regulated by microRNAs in cancer

MicroRNAs (miRNAs) are small endogenous regulatory molecules that modulate gene expression post-transcriptionally. Although differential expression of miRNAs have been implicated in many diseases (including cancers), the underlying mechanisms of action remain unclear. Because each miRNA can target multiple genes, miRNAs may potentially have functional implications for the overall behavior of entire pathways. Here, we investigate the functional consequences of miRNA dysregulation through an integrative analysis of miRNA and mRNA expression data using a novel approach that incorporates pathway information a priori. By searching for miRNA-pathway associations that differ between healthy and tumor tissue, we identify specific relationships at the systems level which are disrupted in cancer. Our approach is motivated by the hypothesis that if an miRNA and pathway are associated, then the expression of the miRNA and the collective behavior of the genes in a pathway will be correlated. As such, we first obtain an expression-based summary of pathway activity using Isomap, a dimension reduction method which can articulate non-linear structure in high-dimensional data. We then search for miRNAs that exhibit differential correlations with the pathway summary between phenotypes as a means of finding aberrant miRNA-pathway coregulation in tumors. We apply our method to cancer data using gene and miRNA expression datasets from The Cancer Genome Atlas and compare ∼10⁵ miRNA-pathway relationships between healthy and tumor samples from four tissues (breast, prostate, lung and liver). Many of the flagged pairs we identify have a biological basis for disruption in cancer.

Cigarette smoke extract alters genome-wide profiles of circular RNAs and mRNAs in primary human small airway epithelial cells

As a novel kind of non-coding RNA, circular RNAs (circRNAs) were involved in various biological processes. However, the role of circRNAs in the developmental process of chronic obstructive pulmonary disease (COPD) is still unclear. In the present study, by using a cell model of COPD in primary human small airway epithelial cells (HSAECs) treated with or without cigarette smoke extract (CSE), we uncovered 4,379 previously unknown circRNAs in human cells and 903 smoke-specific circRNAs, with the help of RNA-sequencing and bioinformatic analysis. Moreover, 3,872 up- and 4,425 down-regulated mRNAs were also identified under CSE stimulation. Furthermore, a putative circRNA-microRNA-mRNA network was constructed for in-depth mechanism exploration, which indicated that differentially expressed circRNAs could influence expression of some key genes that participate in response to pentose phosphate pathway, ATP-binding cassette (ABC) transporters, glycosaminoglycan biosynthesis pathway and cancer-related pathways. Our research indicated that cigarette smoke had an influence on the biogenesis of circRNAs and mRNAs. CircRNAs might be involved in the response to CSE in COPD through the circRNA-mediated ceRNA networks.

Activation of GPR55 induces neuroprotection of hippocampal neurogenesis and immune responses of neural stem cells following chronic, systemic inflammation

New neurons are continuously produced by neural stem cells (NSCs) within the adult hippocampus. Numerous diseases, including major depressive disorder and HIV-1 associated neurocognitive disorder, are associated with decreased rates of adult neurogenesis. A hallmark of these conditions is a chronic release of neuroinflammatory mediators by activated resident glia. Recent studies have shown a neuroprotective role on NSCs of cannabinoid receptor activation. Yet, little is known about the effects of GPR55, a candidate cannabinoid receptor, activation on reductions of neurogenesis in response to inflammatory insult. In the present study, we examined NSCs exposed to IL-1β in vitro to assess inflammation-caused effects on NSC differentiation and the ability of GPR55 agonists to attenuate NSC injury. NSC differentiation and neurogenesis was determined via immunofluorescence and flow cytometric analysis of NSC markers (Nestin, Sox2, DCX, S100β, βIII Tubulin, GFAP). GPR55 agonist treatment protected against IL-1β induced reductions in neurogenesis rates. Moreover, inflammatory cytokine receptor mRNA expression was down regulated by GPR55 activation in a neuroprotective manner. To determine inflammatory responses in vivo, we treated C57BL/6 and GPR55^-/- mice with LPS (0.2 mg/kg/day) continuously for 14 days via osmotic mini-pump. Reductions in NSC survival (as determined by BrdU incorporation), immature neurons, and neuroblast formation due to LPS were attenuated by concurrent direct intrahippocampal administration of the GPR55 agonist, O-1602 (4 µg/kg/day). Molecular analysis of the hippocampal region showed a suppressed ability to regulate immune responses by GPR55^-/- animals manifesting in a prolonged inflammatory response (IL-1β, IL-6, TNFα) after chronic, systemic inflammation as compared to C57BL/6 animals. Taken together, these results suggest a neuroprotective role of GPR55 activation on NSCs in vitro and in vivo and that GPR55 provides a novel therapeutic target against negative regulation of hippocampal neurogenesis by inflammatory insult.

MiR-5571-3p and miR-135b-5p, derived from analyses of microRNA profile sequencing, correlate with increased disease risk and activity of rheumatoid arthritis

OBJECTIVES

This study aimed to investigate microRNA (miRNA) expression profiles in synovium tissues of rheumatoid arthritis (RA) patients by RNA sequencing and to evaluate the values of dysregulated miRNAs in RA diagnosis and monitoring.

METHODS

Thirty RA patients who underwent knee arthroscopy and 30 controls with knee trauma who underwent surgery were consecutively recruited, and synovium tissue samples of both groups were obtained during surgeries. In the exploration part, miRNA and mRNA expression profiles of 3 RA samples and 3 control samples were detected using RNA sequencing then followed by bioinformatic analyses. In the validation part, 5 candidate miRNA levels were detected by quantitative polymerase chain reaction (qPCR) in 30 RA patients and 30 control patients.

RESULTS

In the exploration part, 78 miRNAs and 1582 mRNAs were upregulated while 40 miRNAs and 1295 mRNAs were downregulated in synovium tissue samples of RA patients compared with those of controls. Furthermore, enrichment analyses revealed that these dysregulated miRNAs and mRNAs were mainly implicated in immune activities and inflammatory diseases such as leukocyte migration, complement activation, and RA. In the validation part, qPCR assay revealed that miR-5571-3p and miR-135b-5p expressions were increased in RA patients compared with those in controls and disclosed good predictive values for RA risk with high area under the curves (AUCs). Besides, both miR-5571-3p and miR-135b-5p levels were positively correlated with disease activity and inflammation level of RA.

CONCLUSIONS

Analyses of miRNA expression profiles by sequencing indicate that miR-5571-3p and miR-135b-5p correlate with increased RA risk and activity.

The role of microRNAs in chronic respiratory disease: recent insights

Chronic respiratory diseases encompass a group of diverse conditions affecting the airways, which all impair lung function over time. They include cystic fibrosis (CF), idiopathic pulmonary fibrosis (IPF), chronic obstructive pulmonary disease (COPD) and asthma, which together affect hundreds of millions of people worldwide. MicroRNAs (miRNAs), a class of small non-coding RNAs involved in post-transcriptional gene repression, are now recognized as major regulators in the development and progression of chronic lung disease. Alterations in miRNA abundance occur in lung tissue, inflammatory cells, and freely circulating in blood and are thought to function both as drivers and modifiers of disease. Their importance in lung pathology has prompted the development of miRNA-based therapies and biomarker tools. Here, we review the current literature on miRNA expression and function in chronic respiratory disease and highlight further research that is needed to propel miRNA treatments for lung disorders towards the clinic.

RNAi-based therapeutics for lung cancer: biomarkers, microRNAs, and nanocarriers

INTRODUCTION

Despite the current advances in the discovery of the lung cancer biomarkers and, consequently, in the diagnosis, this pathology continues to be the primary cause of cancer-related death worldwide. In most cases, the illness is diagnosed in an advanced stage, which limits the current treatment options available and reduces the survival rate. Therefore, RNAi-based therapy arises as a promising option to treat lung cancer.

AREAS COVERED

This review provides an overview on the exploitation of lung cancer biology to develop RNAi-based therapeutics to be applied in the treatment of lung cancer. Furthermore, the review analyzes the main nanocarriers designed to deliver RNAi molecules and induce antitumoral effects in lung cancer, and provides updated information about current RNAi-based therapeutics for lung cancer in clinical trials.

EXPERT OPINION

RNAi-based therapy uses nanocarriers to perform a targeted and efficient delivery of therapeutic genes into lung cancer cells, by taking advantage of the known biomarkers in lung cancer. These therapeutic genes are key regulatory molecules of crucial cellular pathways involved in cell proliferation, migration, and apoptosis. Thereby, the characteristics and functionalization of the nanocarrier and the knowledge of lung cancer biology have direct influence in improving the therapeutic effect of this therapy.

The role of noncoding RNAs in regulating epithelial responses in COPD

Chronic obstructive pulmonary disease (COPD), one of the leading causes of death in the world, is a chronic inflammatory disease of the airways usually caused by long-term exposure to inhaled irritants. Airway epithelial cells (AECs) play a key role in initializing COPD and driving the exacerbation of this disease through the release of various cytokines. This AEC-derived cytokine response is tightly regulated possibly through the regulatory effects of noncoding RNAs (ncRNAs). Although the importance of ncRNAs in pulmonary diseases has been increasingly realized, little is known about the role of ncRNA in the regulation of inflammatory responses in COPD. This review outlines the features of AEC-derived cytokine responses in COPD and how ncRNAs regulate these inflammatory responses.

microRNA profiling in lung tissue and bronchoalveolar lavage of cigarette smoke-exposed mice and in COPD patients: a translational approach

Chronic obstructive pulmonary disease (COPD) is characterized by a progressive airflow limitation and is associated with a chronic inflammatory response in both airways and lungs. microRNAs (miRNAs) are often highly conserved between species and have an intricate role within homeostatic conditions and immune responses. Also, miRNAs are dysregulated in smoking-associated diseases. We investigated the miRNA profile of 523 miRNAs by stem-loop RT-qPCR in lung tissue and cell-free bronchoalveolar lavage (BAL) supernatant of mice exposed to air or cigarette smoke (CS) for 4 or 24 weeks. After 24 weeks of CS exposure, 31 miRNAs were differentially expressed in lung tissue and 78 in BAL supernatant. Next, we correlated the miRNA profiling data to inflammation in BAL and lung, obtained by flow cytometry or ELISA. In addition, we surveyed for overlap with newly assessed miRNA profiles in bronchial biopsies and with previously assessed miRNA profiles in lung tissue and induced sputum supernatant of smokers with COPD. Several miRNAs showed concordant differential expression between both species including miR-31*, miR-155, miR-218 and let-7c. Thus, investigating miRNA profiling data in different compartments and both species provided accumulating insights in miRNAs that may be relevant in CS-induced inflammation and the pathogenesis of COPD.

MicroRNAs in lung cancer

Lung cancer (LC) is a serious public health problem responsible for the majority of cancer deaths and comorbidities in developed countries. Tobacco smoking is considered the main risk factor for LC; however, only a few smokers will be affected by this cancer. Current screening methods are focused on identifying the early stages of this malignancy. Thus, new data concerning the roles of microRNA alterations in inflammation, epithelial-mesenchymal transition and lung disease have increased hope about LC pathogenesis, diagnosis, treatment and prognosis. MicroRNA mechanisms include angiogenesis promotion, cell cycle regulation by modulating cellular proliferation and apoptosis, and migration and invasion inhibition. In this context, this manuscript reviews the current information about many important microRNAs as they relate to the initiation and progression of LC.

Multi-walled carbon nanotube-induced genotoxic, inflammatory and pro-fibrotic responses in mice: Investigating the mechanisms of pulmonary carcinogenesis

The International Agency for Research on Cancer has classified one type of multi-walled carbon nanotubes (MWCNTs) as possibly carcinogenic to humans. However, the underlying mechanisms of MWCNT- induced carcinogenicity are not known. In this study, the genotoxic, mutagenic, inflammatory, and fibrotic potential of MWCNTs were investigated. Muta™Mouse adult females were exposed to 36±6 or 109±18μg/mouse of Mitsui-7, or 26±2 or 78±5μg/mouse of NM-401, once a week for four consecutive weeks via intratracheal instillations, alongside vehicle-treated controls. Samples were collected 90days following the first exposure for measurement of DNA strand breaks, lacZ mutant frequency, p53 expression, cell proliferation, lung inflammation, histopathology, and changes in global gene expression. Both MWCNT types persisted in lung tissues 90days post-exposure, and induced lung inflammation and fibrosis to similar extents. However, there was no evidence of DNA damage as measured by the comet assay following Mitsui-7 exposure, or increases in lacZ mutant frequency, for either MWCNTs. Increased p53 expression was observed in the fibrotic foci induced by both MWCNTs. Gene expression analysis revealed perturbations of a number of biological processes associated with cancer including cell death, cell proliferation, free radical scavenging, and others in both groups, with the largest response in NM-401-treated mice. The results suggest that if the two MWCNT types were capable of inducing DNA damage, strong adaptive responses mounted against the damage, resulting in efficient and timely elimination of damaged cells through cell death, may have prevented accumulation of DNA damage and mutations at the post-exposure time point investigated in the study. Thus, MWCNT-induced carcinogenesis may involve ongoing low levels of DNA damage in an environment of persisting fibres, chronic inflammation and tissue irritation, and parallel increases or decreases in the expression of genes involved in several pro-carcinogenic pathways.

Long Noncoding RNA GAS5 Inhibits Tumorigenesis and Enhances Radiosensitivity by Suppressing miR-135b Expression in Non-Small Cell Lung Cancer

Growth arrest-specific transcript 5 (GAS5) has been demonstrated to correlate with clinicopathological characteristics and serve as a tumor suppressor in non-small cell lung cancer (NSCLC). However, the underlying mechanism of the competing endogenous RNA (ceRNA) regulatory network involving GAS5 in NSCLC remains to be elucidated. In this study, qRT-PCR results showed that GAS5 was downregulated and miR-135b was upregulated in NSCLC tissues and cells. The expressions of GAS5 and miR-135b changed inversely in response to irradiation. Gain-of-function experiments revealed that GAS5 overexpression and miR-135b downregulation significantly suppressed tumorigenesis by repressing cell proliferation and invasion, and enhanced the radiosensitivity of NSCLC cells by reducing colony formation rates. Luciferase reporter assay confirmed that GAS5 could directly target miR-135b and negatively regulate its expression. Moreover, rescue experiments demonstrated that miR-135b upregulation markedly abolished GAS5 overexpression-induced tumorigenesis inhibition and radiosensitivity improvement. Furthermore, xenograft model analysis validated that GAS5 overexpression suppressed tumor growth and improved radiosensitivity of NSCLC cells in vivo. Taken together, GAS5 inhibits tumorigenesis and enhances radiosensitivity by suppressing miR-135b expression in NSCLC cells, deepening our understanding of the mechanism of miRNA-lncRNA interaction and providing a novel therapeutic strategy for NSCLC.

Oligonucleotide Therapy for Obstructive and Restrictive Respiratory Diseases

Inhaled oligonucleotide is an emerging therapeutic modality for various common respiratory diseases, including obstructive airway diseases like asthma and chronic obstructive pulmonary disease (COPD) and restrictive airway diseases like idiopathic pulmonary fibrosis (IPF). The advantage of direct accessibility for oligonucleotide molecules to the lung target sites, bypassing systemic administration, makes this therapeutic approach promising with minimized potential systemic side effects. Asthma, COPD, and IPF are common chronic respiratory diseases, characterized by persistent airway inflammation and dysregulated tissue repair and remodeling, although each individual disease has its unique etiology. Corticosteroids have been widely prescribed for the treatment of asthma, COPD, and IPF. However, the effectiveness of corticosteroids as an anti-inflammatory drug is limited by steroid resistance in severe asthma, the majority of COPD cases, and pulmonary fibrosis. There is an urgent medical need to develop target-specific drugs for the treatment of these respiratory conditions. Oligonucleotide therapies, including antisense oligonucleotide (ASO), small interfering RNA (siRNA), and microRNA (miRNA) are now being evaluated both pre-clinically and clinically as potential therapeutics. The mechanisms of action of ASO and siRNA are highly target mRNA specific, ultimately leading to target protein knockdown. miRNA has both biomarker and therapeutic values, and its knockdown by a miRNA antagonist (antagomir) has a broader but potentially more non-specific biological outcome. This review will compile the current findings of oligonucleotide therapeutic targets, verified in various respiratory disease models and in clinical trials, and evaluate different chemical modification approaches to improve the stability and potency of oligonucleotides for the treatment of respiratory diseases.

Aryl hydrocarbon receptor (AhR)-dependent regulation of pulmonary miRNA by chronic cigarette smoke exposure

The aryl hydrocarbon receptor (AhR) is a ligand-activated transcription factor historically known for its toxic responses to man-made pollutants such as dioxin. More recently, the AhR has emerged as a suppressor of inflammation, oxidative stress and apoptosis from cigarette smoke by mechanisms that may involve the regulation of microRNA. However, little is known about the AhR regulation of miRNA expression in the lung in response to inhaled toxicants. Therefore, we exposed Ahr^−/− and Ahr^+/− mice to cigarette smoke for 4 weeks and evaluated lung miRNA expression by PCR array. There was a dramatic regulation of lung miRNA by the AhR in the absence of exogenous ligand. In response to cigarette smoke, there were more up-regulated miRNA in Ahr^−/− mice compared to Ahr^+/− mice, including the cancer-associated miRNA miR-96. There was no significant change in the expression of the AhR regulated proteins HuR and cyclooxygenase-2 (COX-2). There were significant increases in the anti-oxidant gene sulfiredoxin 1 (Srxn1) and FOXO3a- predicted targets of miR-96. Collectively, these data support a prominent role for the AhR in regulating lung miRNA expression. Further studies to elucidate a role for these miRNA may further uncover novel biological function for the AhR in respiratory health and disease.

Tanshinones suppress AURKA through up-regulation of miR-32 expression in non-small cell lung cancer

Tanshinone is the liposoluble constituent of Salia miltiorrhiza, a root used in traditional herbal medicine which is known to possess certain health benefits. Although it is known that tanshinones, including tanshinone I (T1), tanshinone IIA (T2A), and cryptotanshinone (CT), can inhibit the growth of lung cancer cells in vitro, the mechanism under which they act is still unclear. AURKA, an oncogene, encodes a serine-threonine kinase which regulates mitotic processes in mammalian cells. Here, we reported that tanshinones mediate AURKA suppression partly through up-regulating the expression of miR-32. We found that tanshinones could inhibit cell proliferation, promote apoptosis, and impede cell-cycle progression, thus performing an antineoplastic function in non-small cell lung cancer (NSCLC). Additionally, we demonstrated that tanshinones attained these effects in part by down-regulating AURKA, corroborating previous reports. Our results showed that in NSCLC, similar effects were obtained with knock-down of the AURKA gene by siRNA. We also verified that AURKA was the direct target of miR-32. Collectively, our results demonstrated that tanshinones could inhibit NSCLC by suppressing AURKA via up-regulating the expressions of miR-32 and other related miRNAs.

Environmentally induced epigenetic toxicity: potential public health concerns

Throughout our lives, epigenetic processes shape our development and enable us to adapt to a constantly changing environment. Identifying and understanding environmentally induced epigenetic change(s) that may lead to adverse outcomes is vital for protecting public health. This review, therefore, examines the present understanding of epigenetic mechanisms involved in the mammalian life cycle, evaluates the current evidence for environmentally induced epigenetic toxicity in human cohorts and rodent models and highlights the research considerations and implications of this emerging knowledge for public health and regulatory toxicology. Many hundreds of studies have investigated such toxicity, yet relatively few have demonstrated a mechanistic association among specific environmental exposures, epigenetic changes and adverse health outcomes in human epidemiological cohorts and/or rodent models. While this small body of evidence is largely composed of exploratory in vivo high-dose range studies, it does set a precedent for the existence of environmentally induced epigenetic toxicity. Consequently, there is worldwide recognition of this phenomenon, and discussion on how to both guide further scientific research towards a greater mechanistic understanding of environmentally induced epigenetic toxicity in humans, and translate relevant research outcomes into appropriate regulatory policies for effective public health protection.

hsa-miR-29c and hsa-miR-135b differential expression as potential biomarker of gastric carcinogenesis

AIM

To investigate the expression profiles of hsa-miR-29c and hsa-miR-135b in gastric mucosal samples and their values as gastric carcinogenesis biomarkers.

METHODS

The expression levels of hsa-miR-29c and hsa-miR-135b in normal gastric mucosa, non-atrophic chronic gastritis, intestinal metaplasia and intestinal-type gastric adenocarcinoma were analysed using quantitative real-time PCR. The difference between hsa-miR-29c and hsa-miR-135b expression profiles in the grouped samples was evaluated by ANOVA and Student's t-test tests. The results were adjusted for multiple testing by using Bonferroni's correction. P values ≤ 0.05 were considered statistically significant. To evaluate hsa-miR-29c and hsa-miR-135b expressions as potential biomarkers of gastric carcinogenesis, we performed a receiver operating characteristic curve analysis and the derived area under the curve, and a Categorical Principal Components Analysis. In silico identification of the genetic targets of hsa-miR-29c and hsa-miR-135b was performed using different prediction tools, in order to identify possible genes involved in gastric carcinogenesis.

RESULTS

The expression levels of hsa-miR-29c were higher in normal gastric mucosal samples, and decreased progressively in non-atrophic chronic gastritis samples, intestinal metaplasia samples and intestinal-type gastric adenocarcinoma samples. The expression of hsa-miR-29c in the gastric lesions showed that non-atrophic gastritis have an intermediate profile to gastric normal mucosa and intestinal-type gastric adenocarcinoma, and that intestinal metaplasia samples presented an expression pattern similar to that in intestinal-type gastric adenocarcinoma. This microRNA (miRNA) has a good discriminatory accuracy between normal gastric samples and (1) intestinal-type gastric adenocarcinoma; and (2) intestinal metaplasia, and regulates the DMNT3A oncogene. hsa-miR-135b is up-regulated in non-atrophic chronic gastritis and intestinal metaplasia samples and down-regulated in normal gastric mucosa and intestinal-type gastric adenocarcinoma samples. Non-atrophic chronic gastritis and intestinal metaplasia are significantly different from normal gastric mucosa samples. hsa-miR-135b expression presented a greater discriminatory accuracy between normal samples and gastric lesions. This miRNA was associated with Helicobacter pylori presence in non-atrophic chronic gastritis samples and regulates the APC and KLF4 tumour suppressor genes.

CONCLUSION

Our results provide evidence of epigenetic alterations in non-atrophic chronic gastritis and intestinal metaplasia and suggest that hsa-miR-29c and hsa-miR-135b are promising biomarkers of gastric carcinogenesis.

Targeting MicroRNA Function in Respiratory Diseases: Mini-Review

MicroRNAs (miRNAs) are small non-coding RNA molecules that modulate expression of the majority of genes by inhibiting protein translation. Growing literature has identified functional roles for miRNAs across a broad range of biological processes. As such, miRNAs are recognized as potential disease biomarkers and novel targets for therapies. While several miRNA-targeted therapies are currently in clinical trials (e.g., for the treatment of hepatitis C virus infection and cancer), no therapies have targeted miRNAs in respiratory diseases in the clinic. In this mini-review, we review the current knowledge on miRNA expression and function in respiratory diseases, intervention strategies to target miRNA function, and considerations specific to respiratory diseases. Altered miRNA expression profiles have been reported in a number of respiratory diseases, including asthma, chronic obstructive pulmonary disease, cystic fibrosis, and idiopathic pulmonary fibrosis. These include alterations in isolated lung tissue, as well as sputum, bronchoalveolar lavage fluids and peripheral blood or serum. The observed alterations in easily accessible body fluids (e.g., serum) have been proposed as new biomarkers that may inform disease diagnosis and patient management. In a subset of studies, miRNA-targeted interventions also improved disease outcomes, indicating functional roles for altered miRNA expression in disease pathogenesis. In fact, direct administration of miRNA-targeting molecules to the lung has yielded promising results in a number of animal models. The ability to directly administer compounds to the lung holds considerable promise and may limit potential off-target effects and side effects caused by the systemic administration required to treat other diseases.

Integrative miRNA and whole-genome analyses of epicardial adipose tissue in patients with coronary atherosclerosis

BACKGROUND

Epicardial adipose tissue (EAT) is an atypical fat depot surrounding the heart with a putative role in the development of atherosclerosis.

METHODS AND RESULTS

We profiled genes and miRNAs in perivascular EAT and subcutaneous adipose tissue (SAT) of metabolically healthy patients without coronary artery disease (CAD) vs. metabolic patients with CAD. Compared with SAT, a specific tuning of miRNAs and genes points to EAT as a tissue characterized by a metabolically active and pro-inflammatory profile. Then, we depicted both miRNA and gene signatures of EAT in CAD, featuring a down-regulation of genes involved in lipid metabolism, mitochondrial function, nuclear receptor transcriptional activity, and an up-regulation of those involved in antigen presentation, chemokine signalling, and inflammation. Finally, we identified miR-103-3p as candidate modulator of CCL13 in EAT, and a potential biomarker role for the chemokine CCL13 in CAD.

CONCLUSION

EAT in CAD is characterized by changes in the regulation of metabolism and inflammation with miR-103-3p/CCL13 pair as novel putative actors in EAT function and CAD.

Transcriptome analysis provides insights into the regulatory function of alternative splicing in antiviral immunity in grass carp (Ctenopharyngodon idella)

Characterization of the transcriptomic response to infection is an effective approach to understanding the immune mechanisms. Herein we challenged grass carp (Ctenopharyngodon idella) with grass carp reovirus (GCRV) and sequenced four cDNA libraries obtained from head-kidney and spleen by using Illumina Miseq. As a result, we gained a total of 21.52 Gb clean data with 107.96 million reads, and de novo assembled 55,199 unigenes with an average length of 1,470 bp. Comparative transcriptome analysis reveals that 217 unigenes are differentially expressed (fold-change of at least 4) between resistant and susceptible fish in both head-kidney and spleen, and of which 36 unigenes were validated by RT-qPCR experiment. The expression profile of immune-related genes demonstrates that the immune response of spleen is more intense than that of head-kidney. Remarkably, 11,811 unigenes contain multiple transcripts, of which 322 unigenes possess notably differentially expressed transcripts between the four transcriptomic datasets. Furthermore, the splicing transcripts of IL-12p40 and IL-1R1 are firstly found to play diverse roles in the antiviral response of fishes. This study provides a complete transcriptome dataset of C. idella, which is valuable for the studies of immune complexity and, moreover, throws light on the regulatory role of AS in antiviral immunity.

Unravelling the complexity of COPD by microRNAs: it's a small world after all

Chronic obstructive pulmonary disease (COPD) is a progressive lung disease and is currently the fourth leading cause of death worldwide. Chronic inflammation and repair processes in the small airways are characteristic of COPD. Despite extensive efforts from researchers and industry, there is still no cure for COPD, hence an urgent need for new therapeutic alternatives. MicroRNAs are such an option; they are small noncoding RNAs involved in gene regulation. Their importance has been shown with respect to maintaining the balance between health and disease. Although previous reviews have discussed the expression of microRNAs related to lung disease, a detailed discussion regarding the function of differential miRNA expression in the pathogenesis of COPD is lacking.In this review we link the expression of microRNAs to different features of COPD and explain their importance in the pathogenesis of this disease. We further discuss their potential to contribute to the development of future therapeutic strategies.

MiR-135b-5p and MiR-499a-3p Promote Cell Proliferation and Migration in Atherosclerosis by Directly Targeting MEF2C

Proliferation and migration of endothelial cells (ECs) and vascular smooth muscle cells (VSMCs) are critical processes involved in atherosclerosis. Recent studies have revealed that microRNAs (miRNAs) can be detected in circulating blood with a stable form and the expression profiles differ in many cellular processes associated with coronary artery disease (CAD). However, little is known about their role, especially serum-derived miRNAs, in ECs and VSMCs phenotype modulation during atherosclerosis. We compared the miRNA expressions in serum samples from 13 atherosclerotic CAD patients and 5 healthy control subjects and identified 36 differentially expressed miRNAs. The expression of selected miRNAs (miR-135b-5p and miR-499a-3p) was further validated in 137 serum samples. Interestingly, miR-135b-5p and miR-499a-3p directly regulated a common target gene: myocyte enhancer factor 2C (MEF2C) which plays an important role in modulating cell phenotype of cardiovascular systems. Furthermore, our results indicated that the 2 elevated miRNAs could jointly promote ECs and VSMCs proliferation and migration by repressing MEF2C expression. Together, our findings demonstrated a serum-based miRNA expression profile for atherosclerotic CAD patients, potentially revealing a previously undocumented mechanism for cell proliferation and migration mediated by miR-135b-5p and miR-499a-3p, and might provide novel insights into the role of circulating miRNAs in atherosclerosis pathogenesis.

The potential of plasma miRNAs for diagnosis and risk estimation of colorectal cancer

Circulating microRNAs (miRNAs) were recognized to be potential non-invasive biomarkers for colorectal cancer (CRC) detection and prediction. Meanwhile, the association of the expression of plasma miRNAs with the risk of CRC patients has rarely been analyzed. Therefore, we conducted this study to evaluate the value of plasma miRNAs for CRC diagnosis and risk estimation. Fasting blood samples from 100 CRC patients and 79 cancer-free controls were collected. Plasma miR-106a, miR-20a, miR-27b, miR-92a and miR-29a levels were detected by RT-qPCR. Sensitivity and specificity were employed to evaluate the diagnostic value of miRNAs for CRC. Univariate and multivariate logistic regression were employed to analyze the association between miRNAs expression and CRC risk. As results, miR-106a and miR-20a were elevated in the patients with CRC. The sensitivity of miR-106a was 74.00% and the specificity was 44.40%, while the cutoff value was 2.03. As for miR-20a, the sensitivity was 46.00% and specificity was 73.42% when employed 2.44 as cutoff value. High expression of plasma miR-106a increased CRC risk by 1.80 -fold. Plasma miR-106a and miR-20a may as noninvasive biomarkers for detecting the CRC. High expression of miR-106a associated with CRC risk.

Epigenetic mechanisms in nanomaterial-induced toxicity

With the growing advent of nanotechnology in medicine (therapeutic, diagnostic and imaging applications), cosmetics, electronics, clothing and food industries, exposure to nanomaterials (NMs) is on the rise and therefore exploring their toxic biological effects have gained great significance. In vitro and in vivo studies over the last decade have revealed that NMs have the potential to cause cytotoxicity and genotoxicity although some contradictory reports exist. However, there are only few studies which have explored the epigenetic mechanisms (changes to DNA methylation, histone modification and miRNA expression) of NM-induced toxicity, and there is a scarcity of information and many questions in this area remain unexplored and unaddressed. This review comprehensively describes the epigenetic mechanisms involved in the induction of toxicity of engineered NMs, and provides comparisons between similar effects observed upon exposure to small or nanometer-sized particles. Lastly, gaps in existing literature and scope for future studies that improve our understanding of NM-induced epigenetic toxicity are discussed.

The Lung Immune Response to Nontypeable Haemophilus influenzae (Lung Immunity to NTHi)

Haemophilus influenzae is divided into typeable or nontypeable strains based on the presence or absence of a polysaccharide capsule. The typeable strains (such as type b) are an important cause of systemic infection, whilst the nontypeable strains (designated as NTHi) are predominantly respiratory mucosal pathogens. NTHi is present as part of the normal microbiome in the nasopharynx, from where it may spread down to the lower respiratory tract. In this context it is no longer a commensal and becomes an important respiratory pathogen associated with a range of common conditions including bronchitis, bronchiectasis, pneumonia, and particularly chronic obstructive pulmonary disease. NTHi induces a strong inflammatory response in the respiratory tract with activation of immune responses, which often fail to clear the bacteria from the lung. This results in recurrent/persistent infection and chronic inflammation with consequent lung pathology. This review will summarise the current literature about the lung immune response to nontypeable Haemophilus influenzae, a topic that has important implications for patient management.

Non-coding RNAs in the pathogenesis of COPD

A large part of the human genome is transcribed in non-coding RNAs, transcripts that do not code for protein, including microRNAs (miRNAs) and long non-coding RNAs (lncRNAs). MiRNAs are short single-stranded RNA molecules that negatively regulate gene expression at the post-transcriptional level. They play an important regulatory role in many biological processes. Consequently, altered expression of these non-coding RNAs has been shown to lead to inflammation and disease. In contrast, lncRNAs, can both enhance or repress the expression of protein-coding genes. COPD is typically caused by tobacco smoking and leads to a progressive decline in lung function and a premature death. Exaggerated pulmonary inflammation is a hallmark feature in this disease, leading to obstructive bronchiolitis and emphysema. In this review, we discuss the miRNA expression patterns in lungs of patients with COPD and in mouse models and we highlight various miRNAs involved in COPD pathogenesis. In addition, we briefly discuss a specific lncRNA that is upregulated upon cigarette smoke exposure, providing a short introduction to this more recently discovered group of non-coding RNAs.

MicroRNAs as potential signatures of environmental exposure or effect: a systematic review

BACKGROUND

The exposome encompasses all life-course environmental exposures from the prenatal period onward that influence health. MicroRNAs (miRNAs) are interesting entities within this concept as markers and causation of disease. MicroRNAs are short oligonucleotide sequences that can interact with several mRNA targets.

OBJECTIVES

We reviewed the current state of the field on the potential of using miRNAs as biomarkers for environmental exposure. We investigated miRNA signatures in response to all types of environmental exposure to which a human can be exposed, including cigarette smoke, air pollution, nanoparticles, and diverse chemicals; and we examined the health conditions for which the identified miRNAs have been reported (i.e., cardiovascular disease, cancer, and diabetes).

METHODS

We searched the PubMed and ScienceDirect databases to identify relevant studies.

RESULTS

For all exposures incorporated in this review, 27 miRNAs were differentially expressed in at least two independent studies. miRNAs that had expression alterations associated with smoking observed in multiple studies are miR-21, miR-34b, miR-125b, miR-146a, miR-223, and miR-340; and those miRNAs that were observed in multiple air pollution studies are miR-9, miR-10b, miR-21, miR-128, miR-143, miR-155, miR-222, miR-223, and miR-338. We found little overlap among in vitro, in vivo, and human studies between miRNAs and exposure. Here, we report on disease associations for those miRNAs identified in multiple studies on exposure.

CONCLUSIONS

miRNA changes may be sensitive indicators of the effects of acute and chronic environmental exposure. Therefore, miRNAs are valuable novel biomarkers for exposure. Further studies should elucidate the role of the mediation effect of miRNA between exposures and effect through all stages of life to provide a more accurate assessment of the consequences of miRNA changes.

T-ReCS: stable selection of dynamically formed groups of features with application to prediction of clinical outcomes

Feature selection is used extensively in biomedical research for biomarker identification and patient classification, both of which are essential steps in developing personalized medicine strategies. However, the structured nature of the biological datasets and high correlation of variables frequently yield multiple equally optimal signatures, thus making traditional feature selection methods unstable. Features selected based on one cohort of patients, may not work as well in another cohort. In addition, biologically important features may be missed due to selection of other co-clustered features We propose a new method, Tree-guided Recursive Cluster Selection (T-ReCS), for efficient selection of grouped features. T-ReCS significantly improves predictive stability while maintains the same level of accuracy. T-ReCS does not require an a priori knowledge of the clusters like group-lasso and also can handle "orphan" features (not belonging to a cluster). T-ReCS can be used with categorical or survival target variables. Tested on simulated and real expression data from breast cancer and lung diseases and survival data, T-ReCS selected stable cluster features without significant loss in classification accuracy.