MicroRNAs in mucosal inflammation

Targeting hypoxia-inducible factors: therapeutic opportunities and challenges

Hypoxia-inducible factors (HIFs) are highly conserved transcription factors that are crucial for adaptation of metazoans to limited oxygen availability. Recently, HIF activation and inhibition have emerged as therapeutic targets in various human diseases. Pharmacologically desirable effects of HIF activation include erythropoiesis stimulation, cellular metabolism optimization during hypoxia and adaptive responses during ischaemia and inflammation. By contrast, HIF inhibition has been explored as a therapy for various cancers, retinal neovascularization and pulmonary hypertension. This Review discusses the biochemical mechanisms that control HIF stabilization and the molecular strategies that can be exploited pharmacologically to activate or inhibit HIFs. In addition, we examine medical conditions that benefit from targeting HIFs, the potential side effects of HIF activation or inhibition and future challenges in this field.

Exploring the role of IL-1β in inflammatory bowel disease pathogenesis

Interleukin 1β (IL-1β) is a significant mediator of inflammation and tissue damage in IBD. The balance between IL-1β and its endogenous inhibitor-IL-1Ra-, plays a critical role in both initiation and regulation of inflammation. However, the precise role of IL-1β as a causative factor in IBD or simply a consequence of inflammation remains unclear. This review summarizes current knowledge on the molecular and cellular characteristics of IL-1β, describes the existing evidence on the role of this cytokine as a modulator of intestinal homeostasis and an activator of inflammatory responses, and also discusses the role of microRNAs in the regulation of IL-1β-related inflammatory responses in IBD. Current evidence indicates that IL-1β is involved in several aspects during IBD as it greatly contributes to the induction of pro-inflammatory responses through the recruitment and activation of immune cells to the gut mucosa. In parallel, IL-1β is involved in the intestinal barrier disruption and modulates the differentiation and function of T helper (Th) cells by activating the Th17 cell differentiation, known to be involved in the pathogenesis of IBD. Dysbiosis in the gut can also stimulate immune cells to release IL-1β, which, in turn, promotes inflammation. Lastly, increasing evidence pinpoints the central role of miRNAs involvement in IL-1β-related signaling during IBD, particularly in the maintenance of homeostasis within the intestinal epithelium. In conclusion, given the crucial role of IL-1β in the promotion of inflammation and immune responses in IBD, the targeting of this cytokine or its receptors represents a promising therapeutic approach. Further research into the IL-1β-associated post-transcriptional modifications may elucidate the intricate role of this cytokine in immunomodulation.

Interplay of hypoxia-inducible factors and oxygen therapy in cardiovascular medicine

Mammals have evolved to adapt to differences in oxygen availability. Although systemic oxygen homeostasis relies on respiratory and circulatory responses, cellular adaptation to hypoxia involves the transcription factor hypoxia-inducible factor (HIF). Given that many cardiovascular diseases involve some degree of systemic or local tissue hypoxia, oxygen therapy has been used liberally over many decades for the treatment of cardiovascular disorders. However, preclinical research has revealed the detrimental effects of excessive use of oxygen therapy, including the generation of toxic oxygen radicals or attenuation of endogenous protection by HIFs. In addition, investigators in clinical trials conducted in the past decade have questioned the excessive use of oxygen therapy and have identified specific cardiovascular diseases in which a more conservative approach to oxygen therapy could be beneficial compared with a more liberal approach. In this Review, we provide numerous perspectives on systemic and molecular oxygen homeostasis and the pathophysiological consequences of excessive oxygen use. In addition, we provide an overview of findings from clinical studies on oxygen therapy for myocardial ischaemia, cardiac arrest, heart failure and cardiac surgery. These clinical studies have prompted a shift from liberal oxygen supplementation to a more conservative and vigilant approach to oxygen therapy. Furthermore, we discuss the alternative therapeutic strategies that target oxygen-sensing pathways, including various preconditioning approaches and pharmacological HIF activators, that can be used regardless of the level of oxygen therapy that a patient is already receiving.

Research progress in the development of natural-product-based mucosal vaccine adjuvants

Mucosal vaccines have great potential and advantages in preventing infection caused by multiple pathogens. In developing mucosal vaccines, the biggest challenge comes from finding safe and effective adjuvants and drug delivery systems. Great progress has been made in the generation of mucosal adjuvants using detoxified bacterial toxin derivatives, pathogen-related molecules, cytokines, and various vaccine delivery systems. However, many problems, relating to the safety and efficacy of mucosal vaccine adjuvants, remain. Certain natural substances can boost the immune response and thus could be used as adjuvants in vaccination. These natural-product-based immune adjuvants have certain advantages over conventional adjuvants, such as low toxicity, high stability, and low cost of production. In this review, we summarize the latest natural-product-based immune adjuvants, and discuss their properties and clinical applications.

Intestinal recruitment of CCR6-expressing Th17 cells by suppressing miR-681 alleviates endotoxemia-induced intestinal injury and reduces mortality

INTRODUCTION

Sepsis or endotoxemia can induce intestinal dysfunction in the epithelial and immune barrier. Th17 cells, a distinct subset of CD4⁺ T-helper cells, act as "border patrol" in the intestine under pathological condition and in the previous studies, Th17 cells exhibited an ambiguous function in intestinal inflammation. Our study will explore a specific role of Th17 cells and its relevant mechanism in endotoxemia-induced intestinal injury.

MATERIALS AND METHODS

Lipopolysaccharide was used to establish mouse model of endotoxemia. miR-681 was analyzed by RT-PCR and northern blot analysis and its regulation by HIF-1α was determined by chromatin immunoprecipitation and luciferase reporter assay. Intestinal Th17 cells isolated from endotoxemic mice were quantitatively evaluated by flow cytometry and its recruitment to the intestine controlled by miR-681/CCR6 pathway was assessed by using anti-miRNA treatment and CCR6 knockout mice. Intestinal histopathology, villus length, intestinal inflammation, intestinal permeability, bacterial translocation and survival were investigated, by histology and TUNEL analysis, ELISA, measurement of diamine oxidase, bacterial culture, with or without anti-miR-681 treatment in endotoxemic wild-type and (or) CCR6 knockout mice.

RESULTS

In this study, we found that miR-681 was significantly promoted in intestinal Th17 cells during endotoxemia, which was dependent on hypoxia-inducible factor-1α (HIF-1α). Interestingly, miR-681 could directly suppress CCR6, which was a critical modulator for Th17 cell recruitment to the intestines. In vivo, anti-miR-681 enhanced survival, increased number of intestinal Th17 cells, reduced crypt and villi apoptosis, decreased intestinal inflammation and bacterial translocation, resulting in protection against endotoxemia-induced intestinal injury in mice. However, CCR6 deficiency could neutralize the beneficial effect of anti-miR-681 on the intestine during endotoxemia, suggesting that the increment of intestinal Th17 cells caused by anti-miR-681 relies on CCR6 expression.

CONCLUSION

The results of the study indicate that control of intestinal Th17 cells by regulating novel miR-681/CCR6 signaling attenuates endotoxemia-induced intestinal injury.

Innate immunity and immunotherapy for hemorrhagic shock

Hemorrhagic shock (HS) is a shock result of hypovolemic injury, in which the innate immune response plays a central role in the pathophysiology ofthe severe complications and organ injury in surviving patients. During the development of HS, innate immunity acts as the first line of defense, mediating a rapid response to pathogens or danger signals through pattern recognition receptors. The early and exaggerated activation of innate immunity, which is widespread in patients with HS, results in systemic inflammation, cytokine storm, and excessive activation of complement factors and innate immune cells, comprised of type II innate lymphoid cells, CD4⁺ T cells, natural killer cells, eosinophils, basophils, macrophages, neutrophils, and dendritic cells. Recently, compelling evidence focusing on the innate immune regulation in preclinical and clinical studies promises new treatment avenues to reverse or minimize HS-induced tissue injury, organ dysfunction, and ultimately mortality. In this review, we first discuss the innate immune response involved in HS injury, and then systematically detail the cutting-edge therapeutic strategies in the past decade regarding the innate immune regulation in this field; these strategies include the use of mesenchymal stem cells, exosomes, genetic approaches, antibody therapy, small molecule inhibitors, natural medicine, mesenteric lymph drainage, vagus nerve stimulation, hormones, glycoproteins, and others. We also reviewed the available clinical studies on immune regulation for treating HS and assessed the potential of immune regulation concerning a translation from basic research to clinical practice. Combining therapeutic strategies with an improved understanding of how the innate immune system responds to HS could help to identify and develop targeted therapeutic modalities that mitigate severe organ dysfunction, improve patient outcomes, and reduce mortality due to HS injury.

Inflammation resolution in environmental pulmonary health and morbidity

Inflammation and resolution are dynamic processes comprised of inflammatory activation and neutrophil influx, followed by mediator catabolism and efferocytosis. These critical pathways ensure a return to homeostasis and promote repair. Over the past decade research has shown that diverse mediators play a role in the active process of resolution. Specialized pro-resolving mediators (SPMs), biosynthesized from fatty acids, are released during inflammation to facilitate resolution and are deficient in a variety of lung disorders. Failed resolution results in remodeling and cellular deposition through pro-fibrotic myofibroblast expansion that irreversibly narrows the airways and worsens lung function. Recent studies indicate environmental exposures may perturb and deregulate critical resolution pathways. Environmental xenobiotics induce lung inflammation and generate reactive metabolites that promote oxidative stress, injuring the respiratory mucosa and impairing gas-exchange. This warrants recognition of xenobiotic associated molecular patterns (XAMPs) as new signals in the field of inflammation biology, as many environmental chemicals generate free radicals capable of initiating the inflammatory response. Recent studies suggest that unresolved, persistent inflammation impacts both resolution pathways and endogenous regulatory mediators, compromising lung function, which over time can progress to chronic lung disease. Chronic ozone (O3) exposure overwhelms successful resolution, and in susceptible individuals promotes asthma onset. The industrial contaminant cadmium (Cd) bioaccumulates in the lung to impair resolution, and recurrent inflammation can result in chronic obstructive pulmonary disease (COPD). Persistent particulate matter (PM) exposure increases systemic cardiopulmonary inflammation, which reduces lung function and can exacerbate asthma, COPD, and idiopathic pulmonary fibrosis (IPF). While recurrent inflammation underlies environmentally induced pulmonary morbidity and may drive the disease process, our understanding of inflammation resolution in this context is limited. This review aims to explore inflammation resolution biology and its role in chronic environmental lung disease(s).

Alternative adenosine Receptor activation: The netrin-Adora2b link

During hypoxia or inflammation, extracellular adenosine levels are elevated. Studies using pharmacologic approaches or genetic animal models pertinent to extracellular adenosine signaling implicate this pathway in attenuating hypoxia-associated inflammation. There are four distinct adenosine receptors. Of these, it is not surprising that the Adora2b adenosine receptor functions as an endogenous feedback loop to control hypoxia-associated inflammation. First, Adora2b activation requires higher adenosine concentrations compared to other adenosine receptors, similar to those achieved during hypoxic inflammation. Second, Adora2b is transcriptionally induced during hypoxia or inflammation by hypoxia-inducible transcription factor HIF1A. Studies seeking an alternative adenosine receptor activation mechanism have linked netrin-1 with Adora2b. Netrin-1 was originally discovered as a neuronal guidance molecule but also functions as an immune-modulatory signaling molecule. Similar to Adora2b, netrin-1 is induced by HIF1A, and has been shown to enhance Adora2b signaling. Studies of acute respiratory distress syndrome (ARDS), intestinal inflammation, myocardial or hepatic ischemia and reperfusion implicate the netrin-Adora2b link in tissue protection. In this review, we will discuss the potential molecular linkage between netrin-1 and Adora2b, and explore studies demonstrating interactions between netrin-1 and Adora2b in attenuating tissue inflammation.

Differential expression profile of plasma exosomal microRNAs in acute type A aortic dissection with acute lung injury

MicroRNAs (miRNAs) packaged into exosomes mediate cell communication and contribute to the pathogenesis of acute type A aortic dissection (ATAAD) with acute lung injury (ALI). The expression profile of plasma exosomal miRNAs in ATAAD patients with ALI hasn’t been identified. We performed a miRNA-sequencing to analyze the differentially expressed miRNAs (DE-miRNAs) of circulating exosomes in ATAAD patients with ALI compared to patients without ALI, founding 283 specific miRNAs in two groups. We respectively selected the top 10 downregulated and upregulated DE-miRNAs for further studies. The predicted transcription factors (TFs) of these DE-miRNAs were SMAD2, SRSF1, USF1, etc. The Gene Ontology (GO) and Kyoto Encyclopedia Genes and Genomes (KEGG) analysis predicted their target genes mainly involved acute inflammatory response, cell junction, cytoskeleton, NF-κB signaling pathway, etc. Construction and analysis of the PPI network revealed that RHOA and INSR were considered hub genes with the highest connectivity degrees. Moreover, we confirmed two exosomal miRNAs (hsa-miR-485-5p and hsa-miR-206) by real-time quantitative polymerase chain reaction (RT-qPCR) in a validation cohort. Our study identified a plasma exosomal miRNAs signature related to ATAAD with ALI. Certain DE-miRNAs may contribute to the progression of this disease, which help us better understand the pathogenesis of ATAAD with ALI.

MicroRNA-1297 participates in the repair of intestinal barrier injury in patients with HIV/AIDS via negative regulation of PLCβ1

To explore the role of the miRNA-1297/phospholipase Cβ1 (PLCβ1) axis in intestinal barrier injury. Abnormally expressed miR-1297 and its target gene PLCβ1 as well as their transcriptome sequencing were confirmed by bioinformatics analysis. Next, the intestinal barrier injury was induced by lipopolysaccharide (LPS) in the CCCHIE-2 cells. Subsequently, the impacts of miR-1297 and PLCβ1 on the transcriptome were estimated. QRT-PCR and Western blotting were conducted to detect the relative mRNA and protein expressions, respectively. The cell viability and permeability were analyzed by MTT assay and fluorescent yellow detection. miR-1297 was significantly upregulated in patients with human immunodeficiency virus/acquired immunodeficiency syndrome and targeted PLCβ1. Moreover, overexpressed PLCβ1 was mainly enriched in the transforming growth factor-beta signaling pathway, while the knockdown of miR-1297 was focused on the arginine biosynthesis pathway. The overexpression of miR-1297 could reduce the PLCβ1 expression and inhibit the viability of CCCHIE-2 cells injured by LPS, while the effect of the downregulation of miR-1297 was on the opposite. Western blotting and cell fluorescence localization experiments revealed that the inhibition of miR-1297 increased the expressions of PLCβ1 and ZO-1. In addition, the upregulation of miR-1297 strengthened the permeability in cells injured by LPS, as did the knockdown of PLCβ1. miR-1297 could restrain the repair of intestinal barrier injury via negatively regulating PLCβ1 and its tight junction downstream protein ZO-1 in CCC-HIE-2 cells injured by LPS, which indicated that PLCβ1 and miR-1297 might be important targets for the repair of intestinal barrier injury.

Perioperative acute kidney injury: impact and recent update

PURPOSE OF REVIEW

Acute kidney injury (AKI) is common in hospitalized patients and is a major risk factor for increased length of stay, morbidity, and mortality in postoperative patients. There are multiple barriers to reducing perioperative AKI - the etiology is multi-factorial and the diagnosis is fraught with issues. We review the recent literature on perioperative AKI and some considerations for anesthesiologists that examine the far-reaching effects of AKI on multiple organ systems.

RECENT FINDINGS

This review will discuss recent literature that addresses the epidemiology, use of novel biomarkers in risk stratification, and therapeutic modalities for AKI in burn, pediatrics, sepsis, trauma, cardiac, and liver disease, contrast-induced AKI, as well as the evidence assessing goal-directed fluid therapy.

SUMMARY

Recent studies address the use of risk stratification models and biomarkers, more sensitive than creatinine, in the preoperative identification of patients at risk for AKI. Although exciting, these scores and models need validation. There is a need for research assessing whether early AKI detection improves outcomes. Enhanced recovery after surgery utilizing goal-directed fluid therapy has not been shown to make an appreciable difference in the incidence of AKI. Reducing perioperative AKI requires a multi-pronged and possibly disease-specific approach.

Streptococcus gordonii-induced miRNAs regulate CCL20 responses in human oral epithelial cells

The mechanisms through which oral commensal bacteria mitigates uncontrolled inflammatory responses of the oral mucosa remain unknown. Here, we show that representative oral bacterial species normally associated with oral health [S. gordonii (Sg), V. parvula (Vp); A. naeslundii (An); C. sputigena (Cs), and N. mucosa (Nm)] enhanced differential chemokine responses in oral epithelial cells (OECs), with some bacteria (An, Vp, and Nm) inducing higher chemokine levels (CXCL1, CXCL8) than others (Sg, Cs). Although all bacterial species (except Cs) increased CCL20 mRNA levels consistent with protein elevations in cell lysates, only An, Vp and Nm induced higher CCL20 secretion, similar to the effect of the oral pathogen F. nucleatum (Fn). In contrast, most CCL20 remained associated with OECs exposed to Sg and negligible amounts released into the cell supernatants. Consistently, Sg attenuated An-induced CCL20. MiR-4516 and miR-663a were identified as Sg-specifically induced miRNAs modulating validated targets of chemokine-associated pathways. Cell transfection with miR-4516 and miR-663a decreased An- and Fn-induced CCL20. MiRNAs up-regulation and attenuation of An-induced CCL20 by Sg were reversed by catalase. Up-regulation of both miRNAs was specifically enhanced by oral streptococci H₂O₂-producers. These findings suggest that CCL20 levels produced by OECs in response to bacterial challenge are regulated by Sg-induced miR-4516 and miR-663a in a mechanism that involves hydrogen peroxide. This type of molecular mechanism could partly explain the central role of specific oral streptococcal species in balancing inflammatory and antimicrobial responses given the critical role of CCL20 in innate (antimicrobial) and adaptive immunity (modulates Th17 responses).

Sweeteners Maintain Epithelial Barrier Function Through the miR-15b/RECK/MMP-9 Axis, Remodel Microbial Homeostasis, and Attenuate Dextran Sodium Sulfate-Induced Colitis in Mice

Non-nutritive sweeteners are the most widely used food additives designed to provide sweetness and reduce caloric intake. Studies have confirmed a link between sweeteners and colitis, yet supporting scientific data remain exiguous and controversial. In this study, three common sweeteners (Saccharin sodium, Stevioside, and Sucralose) in acceptable daily intake dosage were added to water in order to determine their effects on dextran sodium sulfate-induced colitis in mice. Our results show that the three sweeteners meliorate colitis to varying degrees─Saccharin exerts the most pronounced effect, followed by Stevioside and Sucralose. Intake of sweeteners alleviates colitis symptoms, alters gut microbiota, reshapes the TH17/Treg balance, protects the intestinal barrier, and reduces inflammation. Most significantly, sweeteners can enhance the abundance of Mucispirillum and Alistipes, which are conducive to colitis recovery, and upregulate the expression of E-cadherin through the miR-15b/RECK/MMP-9 axis to improve intestinal barrier integrity. Moreover, by inhibiting the MMP-9/AKT/NF-κB pathway, inflammation is relieved, as reflected in the restoration of the Th17/Treg balance. Our results link the consumption of sweeteners to the remission of colitis, which provides new scientific evidence for the safe use of sweeteners.

miRNA-Signature of Irradiated Ptch1+/- Mouse Lens is Dependent on Genetic Background

One harmful long-term effect of ionizing radiation is cataract development. Recent studies have been focused on elucidating the mechanistic pathways involved in this pathogenesis. Since accumulating evidence has established a role of microRNAs in ocular diseases, including cataract, the goal of this work was to determine the microRNA signature of the mouse lens, at short time periods postirradiation, to understand the mechanisms related to radio-induced cataractogenesis. To evaluate the differences in the microRNA profiles, 10-week-old Patched1 heterozygous (Ptch1+/-) mice, bred onto two different genetic backgrounds (CD1 and C57Bl/6J), received whole-body 2 Gy γ-ray irradiation, and 24 h later lenses were collected. Next-generation sequencing and bioinformatics analysis revealed that genetic background markedly influenced the list of the deregulated microRNAs and the mainly predicted perturbed biological functions of 2 Gy irradiated Ptch1+/- mouse lenses. We identified a subset of microRNAs with a contra-regulated expression between strains, with a key role in regulating Toll-like receptor (TLR)-signaling pathways. Furthermore, a detailed analysis of miRNome data showed a completely different DNA damage response in mouse lenses 24 h postirradiation, mainly mediated by a marked upregulation of p53 signaling in Ptch1+/-/C57Bl/6J lenses that was not detected on a CD1 background. We propose a strict interplay between p53 and TLR signaling in Ptch1+/-/C57Bl/6J lenses shortly after irradiation that could explain both the resistance of this strain to developing lens opacities and the susceptibility of CD1 background to radiation-induced cataractogenesis through activation of epithelial-mesenchymal transition.

The role of microRNAs in regulating cadmium-induced apoptosis by targeting Bcl-2 in IEC-6 cells

Cadmium (Cd) is one of the most harmful environmental pollutants and has been found to have adverse effects on the gut. However, the toxic effects and potential mechanism of Cd on intestinal epithelial cells (IECs) are poorly understood. This study evaluated the effects of Cd exposure (0, 0.25, 0.5, 1, 2, and 4 μM) on IEC-6 cells in terms of cell viability and apoptosis, as well as apoptosis-associated gene expression. The results indicated that low doses (0.25- 1 μM) of Cd exhibited hormetic effects, while high doses of Cd (2 and 4 μM) reduced cell viability. The apoptotic effect increased in a dose-dependent pattern. Moreover, the mRNA levels of the Bcl-2, Bax and Caspase 3 genes were altered, which was in agreement with their protein expression. Based on sequencing analysis, the expression pattern of the microRNAs (miRNAs) changed significantly in the 2 μM Cd-treated group. QRT-PCR verified that 7 miRNAs, including miR-124-3p and miR-370-3p, were all upregulated with dose-effect relationship. Besides, transfection of miR-124-3p and miR-370-3p mimics /inhibitor and Bcl-2 siRNA into IEC-6 cells verified that these two miRNAs could regulate Cd-induced apoptosis by targeting Bcl-2. Finally, the direct targeting relationship between miR-370-3p and Bcl-2 gene was confirmed by luciferase reporter assay. Overall, the results demonstrated that Cd exposure could induce apoptosis in IEC-6 cells. The potential mechanism may be interference with the regulation of Bcl-2 gene expression by miR-370-3p and miR-124-3p.

miRNA-223 as a regulator of inflammation and NLRP3 inflammasome, the main fragments in the puzzle of immunopathogenesis of different inflammatory diseases and COVID-19

Millions of people around the world are involved with COVID-19 due to infection with SARS-CoV-2. Virological features of SARS-CoV-2, including its genomic sequence, have been identified but the mechanisms governing COVID-19 immunopathogenesis have remained uncertain. miR-223 is a hematopoietic cell-derived miRNA that is implicated in regulating monocyte-macrophage differentiation, neutrophil recruitment, and pro-inflammatory responses. The miR-223 controls inflammation by targeting a variety of factors, including TRAF6, IKKα, HSP-70, FOXO1, TLR4, PI3K/AKT, PARP-1, HDAC2, ITGB3, CXCL2, CCL3, IL-6, IFN-I, STMN1, IL-1β, IL-18, Caspase-1, NF-κB, and NLRP3. The key role of miR-223 in regulating the inflammatory process and its antioxidant and antiviral role can suggest this miRNA as a potential regulatory factor in the process of COVID-19 immunopathogenesis.

Characterization of a Murine Model System to Study MicroRNA-147 During Inflammatory Organ Injury

Inflammatory organ injury and sepsis have profound impacts on the morbidity and mortality of surgical and critical care patients. MicroRNAs are small RNAs composed of 20-25 nucleotides that have a significant contribution to gene regulation. MicroRNA-147 (miR-147), in particular, has been shown to have an emerging role in different physiological functions such as cell cycle regulation and inflammatory responses. However, animal model systems to study tissue-specific functions of miR-147 during inflammatory conditions in vivo are lacking. In the present study, we characterize miR-147 expression in different organs and cell types. Next, we generated a transgenic mouse line with a floxed miR-147 gene. Subsequently, we used this mouse line to generate mice with whole-body deletion of miR-147 (miR-147 -/-) by crossing "floxed" miR-147 mice with transgenic mice expressing Cre recombinase in all tissues (CMVcre mice). Systematic analysis of miR-147 -/- mice demonstrates normal growth, development, and off-spring. In addition, deletion of the target gene in different organs was successful at baseline or during inflammation, including the heart, intestine, stomach, liver, spleen, bone marrow, lungs, kidneys, or stomach. Moreover, miR-147 -/- mice have identical baseline inflammatory gene expression compared to C57BL/6 mice, except elevated IL-6 expression in the spleen (7.5 fold, p < 0.05). Taken together, our data show the successful development of a transgenic animal model for tissue and cell-specific deletion of miR-147 that can be used to study the functional roles of miR-147 during inflammatory organ injury.

miR-4456/CCL3/CCR5 Pathway in the Pathogenesis of Tight Junction Impairment in Chronic Obstructive Pulmonary Disease

Background: Cigarette smoke exposure (CSE) is a major cause of chronic obstructive pulmonary disease (COPD). The smoke disrupts cell-cell adhesion by inducing epithelial barrier damage to the tight junction (TJ) proteins. Even though the inflammatory mechanism of chemokine (C-C motif) ligand 3 (CCL3) in COPD has gained increasing attention in the research community, however, the underlying signaling pathway, remains unknown.

Objectives: To identify the relationship of CCL3 in the pathogenesis of tight junction impairment in COPD and the pathway through which CSE causes damage to TJ in COPD via CCL3, both in vivo and in vitro.

Methods: We screened the inflammatory factors in the peripheral blood mononuclear cells (PBMCs) from healthy controls and patients at each GOLD 1-4 stage of chronic obstructive pulmonary disease. RT-PCR, western blot, and ELISA were used to detect the levels of CCL3, ZO-1, and occludin after Cigarette smoke exposure. Immunofluorescence was applied to examine the impairment of the TJs in 16-HBE and A549 cells. The reverse assay was used to detect the effect of a CCR5 antagonist (DAPTA) in COPD. In the CSE-induced COPD mouse model, H&E staining and lung function tests were used to evaluate the pathological and physical states in each group. Immunofluorescence was used to assess the impairment of TJs in each group. ELISA and RT-PCR were used to examine the mRNA or protein expression of CCL3 or miR-4456 in each group.

Results: The in vivo and in vitro results showed that CCL3 expression was increased in COPD compared with healthy controls. CCL3 caused significant injury to TJs through its C-C chemokine receptor type 5 (CCR5), while miR-4456 could suppress the effect of CCL3 on TJs by binding to the 3′-UTR of CCL3.

Conclusion: miR-4456/CCL3/CCR5 pathway may be a potential target pathway for the treatment of COPD.

The Role of MicroRNAs in Acute Respiratory Distress Syndrome and Sepsis, From Targets to Therapies: A Narrative Review

Acute respiratory distress syndrome (ARDS) is a significant cause of morbidity and mortality in the intensive care unit (ICU) and is characterized by lung epithelial and endothelial cell injury, with increased permeability of the alveolar-capillary membrane, leading to pulmonary edema, severe hypoxia, and difficulty with ventilation. The most common cause of ARDS is sepsis, and currently, treatment of ARDS and sepsis has consisted mostly of supportive care because targeted therapies have largely been unsuccessful. The molecular mechanisms behind ARDS remain elusive. Recently, a number of microRNAs (miRNAs) identified through high-throughput screening studies in ARDS patients and preclinical animal models have suggested a role for miRNA in the pathophysiology of ARDS. miRNAs are small noncoding RNAs ranging from 18 to 24 nucleotides that regulate gene expression via inhibition of the target mRNA translation or by targeting complementary mRNA for early degradation. Unsurprisingly, some miRNAs that are differentially expressed in ARDS overlap with those important in sepsis. In addition, circulatory miRNA may be useful as biomarkers or as targets for pharmacologic therapy. This can be revolutionary in a syndrome that has neither a measurable indicator of the disease nor a targeted therapy. While there are currently no miRNA-based therapies targeted for ARDS, therapies targeting miRNA have reached phase II clinical trials for the treatment of a wide range of diseases. Further studies may yield a unique miRNA profile pattern that serves as a biomarker or as targets for miRNA-based pharmacologic therapy. In this review, we discuss miRNAs that have been found to play a role in ARDS and sepsis, the potential mechanism of how particular miRNAs may contribute to the pathophysiology of ARDS, and strategies for pharmacologically targeting miRNA as therapy.

Strategies to Modulate MicroRNA Functions for the Treatment of Cancer or Organ Injury

Cancer and organ injury-such as that occurring in the perioperative period, including acute lung injury, myocardial infarction, and acute gut injury-are among the leading causes of death in the United States and impose a significant impact on quality of life. MicroRNAs (miRNAs) have been studied extensively during the last two decades for their role as regulators of gene expression, their translational application as diagnostic markers, and their potential as therapeutic targets for disease treatment. Despite promising preclinical outcomes implicating miRNA targets in disease treatment, only a few miRNAs have reached clinical trials. This likely relates to difficulties in the delivery of miRNA drugs to their targets to achieve efficient inhibition or overexpression. Therefore, understanding how to efficiently deliver miRNAs into diseased tissues and specific cell types in patients is critical. This review summarizes current knowledge on various approaches to deliver therapeutic miRNAs or miRNA inhibitors and highlights current progress in miRNA-based disease therapy that has reached clinical trials. Based on ongoing advances in miRNA delivery, we believe that additional therapeutic approaches to modulate miRNA function will soon enter routine medical treatment of human disease, particularly for cancer or perioperative organ injury. SIGNIFICANCE STATEMENT: MicroRNAs have been studied extensively during the last two decades in cancer and organ injury, including acute lung injury, myocardial infarction, and acute gut injury, for their regulation of gene expression, application as diagnostic markers, and therapeutic potentials. In this review, we specifically emphasize the pros and cons of different delivery approaches to modulate microRNAs, as well as the most recent exciting progress in the field of therapeutic targeting of microRNAs for disease treatment in patients.

Intestinal barrier damage, systemic inflammatory response syndrome, and acute lung injury: A troublesome trio for acute pancreatitis

Severe acute pancreatitis (SAP), a serious inflammatory disease of the pancreas, can easily lead to systemic inflammatory response syndrome (SIRS) and multiple organ dysfunction syndromes (MODS). Acute lung injury (ALI) is one of the most serious complications of SAP. However, the specific pathogenesis of SAP-associated ALI is not fully understood. Crosstalk and multi-mechanisms involving pancreatic necrosis, bacteremia, intestinal barrier failure, activation of inflammatory cascades and diffuse alveolar damage is the main reason for the unclear pathological mechanism of SAP-associated ALI. According to previous research on SAP-associated ALI in our laboratory and theories put forward by other scholars, we propose that the complex pattern of SAP-associated ALI is based on the "pancreas-intestine-inflammation/endotoxin-lung (P-I-I/E-L) pathway". In this review, we mainly concentrated on the specific details of the "P-I-I/E-L pathway" and the potential treatments or preventive measures for SAP-associated ALI.

The effect of baicalin on microRNA expression profiles in porcine aortic vascular endothelial cells infected by Haemophilus parasuis

Glässer's disease, caused by Haemophilus parasuis (H. parasuis), is associated with vascular damage and vascular inflammation in pigs. Therefore, early assessment and treatment are essential to control the inflammatory disorder. MicroRNAs have been shown to be involved in the vascular pathology. Baicalin has important pharmacological functions, including anti-inflammatory, antimicrobial and antioxidant effects. In this study, we investigated the changes of microRNAs in porcine aortic vascular endothelial cells (PAVECs) induced by H. parasuis and the effect of baicalin in this model by utilizing high-throughput sequencing. The results showed that 155 novel microRNAs and 76 differentially expressed microRNAs were identified in all samples. Subsequently, Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis of the target genes of the differentially expressed microRNAs demonstrated that regulation of actin cytoskeleton, focal adhesion, ECM-receptor interaction, bacterial invasion of epithelial cells, and adherens junction were the most interesting pathways after PAVECs were infected with H. parasuis. In addition, when the PAVECs were pretreated with baicalin, mismatch repair, peroxisome, oxidative phosphorylation, DNA replication, and ABC transporters were the most predominant signaling pathways. STRING analysis showed that most of the target genes of the differentially expressed microRNAs were associated with each other. The expression levels of the differentially expressed microRNAs were negatively co-regulated with their target genes' mRNA following pretreatment with baicalin in the H. parasuis-induced PAVECs using co-expression networks analysis. This is the first report that microRNAs might have key roles in inflammatory damage of vascular tissue during H. parasuis infection. Baicalin regulated the microRNAs changes in the PAVECs following H. parasuis infection, which may represent useful novel targets to prevent or treat H. parasuis infection.

Serum miRNAs Are Pharmacodynamic Biomarkers Associated With Therapeutic Response in Pediatric Inflammatory Bowel Disease

BACKGROUND

We sought to identify microRNAs (miRNAs) associated with response to anti-TNF-α or glucocorticoids in children with inflammatory bowel disease (IBD) to generate candidate pharmacodynamic and monitoring biomarkers.

METHODS

Clinical response was assessed by Pediatric Crohn's Disease Activity Index and Pediatric Ulcerative Colitis Activity Index. Quantitative real-time polymerase chain reaction via Taqman Low-Density Array cards were used to identify miRNAs in a discovery cohort of responders (n = 11) and nonresponders (n = 8). Seven serum miRNAs associated with clinical response to treatment, along with 4 previously identified (miR-146a, miR-146b, miR-320a, miR-486), were selected for further study. Candidates were assessed in a validation cohort of serum samples from IBD patients pre- and post-treatment and from healthy controls. Expression of miRNA was also analyzed in inflamed mucosal biopsies from IBD patients and non-IBD controls.

RESULTS

Discovery cohort analysis identified 7 miRNAs associated with therapeutic response: 5 that decreased (miR-126, miR-454, miR-26b, miR-26a, let-7c) and 2 that increased (miR-636, miR-193b). In the validation cohort, 7 of 11 candidate miRNAs changed in the same direction with response to anti-TNF-α therapies, glucocorticoids, or both. In mucosal biopsies, 7 out of 11 miRNAs were significantly increased in IBD vs healthy controls.

CONCLUSIONS

Five candidate miRNAs associated with clinical response and mucosal inflammation in pediatric IBD patients were identified (miR-126, let-7c, miR-146a, miR-146b, and miR-320a). These miRNAs may be further developed as pharmacodynamic and response monitoring biomarkers for use in clinical care and trials.

Upregulation of microRNA-219-5p relieves ulcerative colitis through balancing the differentiation of Treg/Th17 cells

OBJECTIVE

This study aimed to investigate the specific regulatory roles of microRNA-219-5p (miR-219-5p) on ulcerative colitis (UC), and reveal the potential mechanisms relating with the differentiation of Treg/Th17 cells.

METHODS

The mouse model of chronic UC was established by oral administration of 3% dextran sodium sulfate for three cycles. After intravenous injected with lentivirus (LV)-miR-219-5p for 24 h, the disease activity index (DAI), colon length, as well as the serum levels of Interleukin (IL)-6, -17A, -21, and -23 were measured. In addition, the histopathological changes in colon tissues were observed by Hematoxylin-eosin staining. The differentiation of Treg/Th17 cells was detected by Flow cytometry, and the expression of retinoic acid-related orphan receptor (RORrt), signal transducer and activator of transcription 3 (STAT3), and forkhead box p3 (Foxp3) were detected by quantitative real-time PCR and Western blot.

RESULTS

MiR-219-5p was downregulated in colonic mucosal tissues of UC mice (P < 0.05). UC mice injected with LV-miR-219-5p exhibited significantly relieved histopathological changes of colon tissues, increased colon length, decreased DAI, as well as decreased serum levels of IL-6, -17A, -21, and -23 (P < 0.05). In addition, the injection of LV-miR-219-5p significantly increased the percentage of Treg cells via upregulating Foxp3, and decreased the percentage of Th17 cells via downregulating RORrt and STAT3 in UC mice (P < 0.05).

CONCLUSION

The upregulation of miR-219-5p relieved the colonic damage and inflammation of UC through balancing the differentiation of Treg/Th17 cells.

microRNA-223 promotes autophagy to aggravate lung ischemia-reperfusion injury by inhibiting the expression of transcription factor HIF2α

Lung ischemia-reperfusion (I/R) injury severely endangers human health, and recent studies have suggested that certain microRNAs (miRNAs) play important roles in this pathological phenomenon. The current study aimed to ascertain the ability of miR-223 to influence lung I/R injury by targeting hypoxia-inducible factor-2α (HIF2α). First, mouse models of lung I/R injury were established: during surgical procedures, pulmonary arteries and veins and unilateral pulmonary portal vessels were blocked and resuming bilateral pulmonary ventilation, followed by restoration of bipulmonary ventilation. In addition, a lung I/R injury cell model was constructed by exposure to hypoxic reoxygenation (H/R) in mouse pulmonary microvascular endothelial cells (PMVECs). Expression of miR-223, HIF2α and β-catenin in tissues or cells was determined by RT-qPCR and Western blot analysis. Correlation between miR-223 and HIF2α was analyzed by dual luciferase reporter gene assay. Further, lung tissue injury and mouse PMVEC apoptosis was evaluated by HE, TUNEL staining and flow cytometry. Autophagosomes in cells were detected by light chain3 immunofluorescence assay. miR-223 was expressed at a high level while HIF2α/β-catenin was downregulated in tissues and cells with lung I/R injury. Further, miR-223 targeted and repressed HIF2α expression to downregulate β-catenin expression. The miR-223/HIF2α/β-catenin axis aggravated H/R injury in mouse PMVECs and lung I/R injury in mice by enhancing autophagy. Taken together, miR-223 inhibits HIF2α to repress β-catenin, thus contributing to autophagy to complicate lung I/R injury. These findings provide a promising therapeutic target for treating lung I/R injury.

Perioperative Acute Kidney Injury

Perioperative organ injury is among the leading causes of morbidity and mortality of surgical patients. Among different types of perioperative organ injury, acute kidney injury occurs particularly frequently and has an exceptionally detrimental effect on surgical outcomes. Currently, acute kidney injury is most commonly diagnosed by assessing increases in serum creatinine concentration or decreased urine output. Recently, novel biomarkers have become a focus of translational research for improving timely detection and prognosis for acute kidney injury. However, specificity and timing of biomarker release continue to present challenges to their integration into existing diagnostic regimens. Despite many clinical trials using various pharmacologic or nonpharmacologic interventions, reliable means to prevent or reverse acute kidney injury are still lacking. Nevertheless, several recent randomized multicenter trials provide new insights into renal replacement strategies, composition of intravenous fluid replacement, goal-directed fluid therapy, or remote ischemic preconditioning in their impact on perioperative acute kidney injury. This review provides an update on the latest progress toward the understanding of disease mechanism, diagnosis, and managing perioperative acute kidney injury, as well as highlights areas of ongoing research efforts for preventing and treating acute kidney injury in surgical patients.

MicroRNA Determines the Fate of Intestinal Epithelial Cell Differentiation and Regulates Intestinal Diseases

The rapid self-renewal of intestinal epithelial cells enhances intestinal function, promotes the nutritional needs of animals and strengthens intestinal barrier function to resist the invasion of foreign pathogens. MicroRNAs (miRNAs) are a class of short-chain, non-coding RNAs that regulate stem cell proliferation and differentiation by down-regulating hundreds of conserved target genes after transcription via seed pairing to the 3' untranslated regions. Numerous studies have shown that miRNAs can improve intestinal function by participating in the proliferation and differentiation of different cell populations in the intestine. In addition, miRNAs also contribute to disease regulation and therefore not only play a vital role in the gastrointestinal disease management but also act as blood or tissue biomarkers of disease. As changes to the levels of miRNAs can change cell fates, miRNA-mediated gene regulation can be used to update therapeutic strategies and approaches to disease treatment.

Inflammation-Related MicroRNAs Are Associated with Plaque Stability Calculated by IVUS in Coronary Heart Disease Patients

Objectives

This study aimed to investigate the association between inflammation-related microRNAs (miR-21, 146a, 155) and the plaque stability in coronary artery disease patients.

Methods

The expression of miR-21, 146a, and 155 was measured by real-time PCR in 310 consecutive patients. The level of hs-CRP, IL-6, and IL-8 was measured by ELISA. The plaque stability of coronary stenotic lesions was evaluated with intravascular ultrasound (IVUS).

Results

(1) The levels of hs-CRP, IL-6, and IL-8 were significantly increased in the UAP and AMI groups compared with the CPS group (P < 0.01). (2) The expression of miR-21 and miR-146a in peripheral blood mononuclear cells (PBMCs) and plasma was significantly higher in CAD patients compared with non-CAD patients, whereas the miR-155 expression in PBMCs and plasma was significantly lower in patients with CAD. (3) The miR-21 expression in PBMCs was higher in UAP and AMI groups compared with CPS group. The miR-146a expression in PBMCs was higher in SAP, UAP, and AMI groups than in CPS group. Although the level of miR-155 in PBMCs was lower in SAP, UAP, and AMI groups than in CPS group. The expression patterns of miR-21, miR-146a, and miR-155 in plasma were consistent with those of PBMCs. (4) The expressions of miR-21 and miR-146a in PBMCs and plasma were significantly higher in the vulnerable plaque group than those in stable plaque group. While miR-155 in PBMCs and plasma was significantly lower in vulnerable plaque group compared with stable plaque group. (5) The levels of miR-21 and miR-146a in PBMCs and plasma were significantly higher in soft plaque group than in fibrous plaque group and calcified plaque group. However, miR-155 in PBMCs and plasma was significantly lower in soft plaque group.

Conclusions

The expression of miR-21 and miR-146a are associated with the plaque stability in coronary stenotic lesions, whereas miR-155 expression is inversely associated with the plaque stability.

miR-488 mediates negative regulation of the AKT/NF-κB pathway by targeting Rac1 in LPS-induced inflammation

Endometritis is an inflammatory change in the structure of the endometrium due to various causes and is a common cause of infertility. Studies have confirmed that microRNAs (miRNAs) play a key regulatory role in various inflammatory diseases. However, the miRNA-mediated mechanism of endometrial inflammation induced by lipopolysaccharides (LPS) remains unclear. In this study, real-time quantitative polymerase chain reaction, Western blot analysis, immunofluorescence and Rac family small GTPase 1 (Rac1) interference were used to reveal the overexpression of miR-488 in the LPS-induced bovine uterus, and the effect of protein kinase B κ-light chain enhancement of the nuclear factor-activated B cells (AKT/NF-κB) pathway in intimal epithelial cells. The results showed that the expression of inflammatory cytokines such as interleukin-1β (IL-1β), IL-6, and tumor necrosis factor-α in the experimental group was significantly lower than that in the control group when miR-488 was overexpressed. Similar results were observed in the expression levels of p-AKT, p-IKK, and p-p65 proteins. In addition, the dual-luciferase reporter system confirmed that miRNA-488 may directly target the 3'-untranslated region of Rac1. In turn, the expression of Rac1 was inhibited. Moreover, the nuclear translocation of NF-κB was inhibited, and meanwhile, the accumulation of reactive oxygen species (ROS) in the cells was reduced. Thus, we provide basic data for the negative regulation of miR-488 in LPS-induced inflammation by inhibiting ROS production and the AKT/NF-kB pathway in intimal epithelial cells.

The role of the miR1976/CD105/integrin αvβ6 axis in vaginitis induced by Escherichia coli infection in mice

Vaginitis is very common among women, especially women of childbearing age, and is associated with significantly increased risk of preterm birth and pelvic inflammatory diseases. An imbalance in the vaginal flora, the primary cause of vaginitis, promotes the initiation and progression of vaginal infections. However, the responsible mechanisms are still poorly understood. Using a murine vaginitis model of Escherichia coli infection, we demonstrated that decreased expression of microRNA1976 and increased expression of CD105 and integrin αvβ6 were closely associated with the progression of vaginal infection. Importantly, we demonstrated for the first time that the microRNA1976/CD105/integrin αvβ6 axis regulates E. coli-mediated vaginal infection in mice, as evidenced by the finding that E. coli-induced vaginal infection was reversed by microRNA1976 overexpression and exacerbated by CD105 overexpression. The regulation of CD105 and integrin αvβ6 by microRNA1976 was further confirmed in a murine model of vaginitis with adenoviral vector treatment. Taken together, our data suggested that microRNA1976 negatively regulates E. coli-induced vaginal infection in mice at least in part by suppressing CD105 and integrin αvβ6 expression. These findings may provide new insight into the mechanisms of E. coli-induced vaginitis, identify a novel diagnostic biomarker and a potential therapeutic target for flora imbalance-associated vaginitis.

Helicobacter pylori CagA promotes the malignant transformation of gastric mucosal epithelial cells through the dysregulation of the miR-155/KLF4 signaling pathway

The Helicobacter pylori (H. pylori) cytotoxin-associated gene A (CagA) and Krüppel-like transcription factor (KLF4) were both closely associated with the development and progression of gastric cancer (GC). However, the nature of the interactions between CagA and KLF4 in GC development has not been elucidated. Therefore, we focused on the CagA-mediated promotion of the malignant transformation of gastric epithelial cells. Herein, we first examined the expression of KLF4 in both human cancer and paracarcinoma tissues with or without H. pylori infection and found that KLF4 expression was significantly decreased in H. pylori-positive GC cells compared with the H. pylori-negative GC cells. Further functional studies revealed that the increased expression of CagA could suppress KLF4 expression and promote the malignant transformation of normal epithelial cells. Subsequently, we found that CagA could upregulate miR-155 and further restrict the expression of downstream KLF4. More importantly, the overexpression of miR-155 in GES-1 promoted epithelial-mesenchymal transition and eventually facilitated tumor growth in vivo. Overall, the identification of the CagA/miR-155/KLF4 signaling pathway provided a new insight into the development and treatment of GC.

Effects of microRNA-208a on inflammation and oxidative stress in ketamine-induced cardiotoxicity through Notch/NF-κB signal pathways by CHD9

Background: MicroRNA can regulate gene expression, and participate in multiple vital activities, such as inflammation, oxidative stress epigenetic modification, cell proliferation, and apoptosis. It plays an important role in the genesis and development of cardiovascular disease.Objective: To assess the role of microRNA-208a in ketamine-induced cardiotoxicity.Methods: All rats were randomly selected into two groups: sham and model groups. After fixed, all rats in the model group was intraperitoneally (IP) injected with 100 mg/kg of ketamine. Heart samples were stained with HE assay. Total RNAs from serum were used to hybridize with the SurePrint G3 Rat Whole Genome GE 8×60 K Microarray G4858A platform.Results: In the rat model with ketamine-induced cardiotoxicity, microRNA-208a expression was increased. Then, over-expression of microRNA-208a increased inflammation and oxidative stress in vitro model. However, down-regulation of microRNA-208a decreased inflammation and oxidative stress in vitro model. Over-expression of microRNA-208a suppressed CHD9 and Notch1, and induced p65 protein expression in vitro model. Overexpression of CHD9 reduced the effects of microRNA-208a on inflammation and oxidative stress in heart cell through Notch/p65 signal pathways. Notch1 activation reduced the effects of microRNA-208a on inflammation and oxidative stress in heart cell through p65 signal pathways.Conclusion: MicroRNA-208a may be a potential biomarker for ketamine-induced cardiotoxicity through inflammation and oxidative stress by Notch/NF-κB signal pathways by CHD9.

MicroRNA‑223 attenuates LPS‑induced inflammation in an acute lung injury model via the NLRP3 inflammasome and TLR4/NF‑κB signaling pathway via RHOB

Acute lung injury (ALI) and the more severe acute respiratory distress syndrome are common and complex inflammatory lung diseases. MicroRNAs (miRs) have emerged as novel gene regulatory molecules, serving a crucial role in a variety of complex diseases, including ALI. In the present study, the anti‑inflammatory action of miR‑223 on inflammation in ALI was demonstrated and the possible mechanism was further examined. In lipopolysaccharide‑induced ALI, the expression of miR‑223 was reduced compared with that in the control normal group. An in vitro model was used to analyze the effect of miR‑223 downregulation on an ALI model, which increased inflammation, and induced the activation of the NACHT, LRR and PYD domains‑containing protein 3 (NLRP3) inflammasome and Toll‑like receptor 4 (TLR4)/nuclear factor (NF)‑κB signaling pathway via rho‑related GTP‑binding protein RhoB (RHOB). In addition, the overexpression of miR‑223 reduced inflammation and suppressed the NLRP3 inflammasome and TLR4/NF‑κB signaling pathway via RHOB in the in vitro model. Furthermore, TLR4 inhibitor or NLRP3 inhibitor reduced the pro‑inflammatory effect of miR‑223 downregulation in ALI. In conclusion, the results of the present study indicated that miR‑223 functioned as a biological indicator by regulating inflammation in ALI, and may represent a novel potential therapeutic target and prognostic marker of ALI.

MicroRNA repertoire and comparative analysis of Andrias davidianus infected with ranavirus using deep sequencing

Andrias davidianus is a large and economically important amphibian in China. Ranavirus infection causes serious losses in A. davidianus farming industry. MicroRNA mediated host-pathogen interactions are important in antiviral defense. In this study, five small-RNA libraries from ranavirus infected and non-infected A. davidianus spleens were sequenced using high throughput sequencing. The miRNA expression pattern, potential functions, and target genes were investigated. In total, 1356 known and 431 novel miRNAs were discovered. GO and KEGG analysis revealed that certain miRNA target genes are associated with apoptotic, signal pathway, and immune response categories. Analysis identified 82 downregulated and 9 upregulated differentially expressed miRNAs, whose putative target genes are involved in pattern-recognition receptor signaling pathways and immune response. These findings suggested miRNAs play key roles in A. davidianus's response to ranavirus and could provide a reference for further miRNA functional identification, leading to novel approaches to improve A. davidianus ranavirus resistance.

MiR-663, a MicroRNA Linked with Inflammation and Cancer That Is under the Influence of Resveratrol

Resveratrol (trans-3,5,4′-trihydroxystilbene, RSV) is a non-flavonoid dietary polyphenol with antioxidant, anti-inflammatory and anti-cancer properties that is primarily found in red berries. While RSV displays many beneficial effects in vitro, its actual effects in vivo or in animal models remain passionately debated. Recent publications suggest that RSV pleiotropic effects could arise from its capability to regulate the expression and activity of microRNAs, short regulators themselves capable of regulating up to several hundreds of target genes. In particular, RSV increases microRNA miR-663 expression in different human cell lines, suggesting that at least some of its multiple beneficial properties are through the modulation of expression of this microRNA. Indeed, the expression of microRNA miR-663 is reduced in certain cancers where miR-663 is considered to act as a tumor suppressor gene, as well as in other pathologies such as cardiovascular disorders. Target of miR-663 include genes involved in tumor initiation and/or progression as well as genes involved in pathologies associated with chronic inflammation. Here, we review the direct and indirect effects of RSV on the expression of miR-663 and its target transcripts, with emphasise on TGFβ1, and their expected health benefits, and argue that elucidating the molecular effects of different classes of natural compounds on the expression of microRNAs should help to identify new therapeutic targets and design new treatments.

MicroRNA miR-223 as regulator of innate immunity

MicroRNAs were discovered more than 2 decades ago and have profound impact on diverse biological processes. Specific microRNAs have important roles in modulating the innate immune response and their dysregulation has been demonstrated to contribute to inflammatory diseases. MiR-223 in particular, is very highly expressed and tightly regulated in hematopoietic cells. It functions as key modulator for the differentiation and activation of myeloid cells. The central role of miR-223 in myeloid cells, especially neutrophil and macrophage differentiation and activation has been studied extensively. MiR-223 contributes to myeloid differentiation by enhancing granulopoiesis while inhibiting macrophage differentiation. Uncontrolled myeloid activation has detrimental consequences in inflammatory disease. MiR-223 serves as a negative feedback mechanism controlling excessive innate immune responses in the maintenance of myeloid cell homeostasis. This review summarizes several topics covering the function of miR-223 in myeloid differentiation, neutrophil and macrophage functions, as well as in inflammatory diseases including acute respiratory distress syndrome and inflammatory bowel disease. In addition, nonmyeloid functions of miR-223 are also discussed in this review. Therapeutic enhancement of miR-223 to dampen inflammatory targets is also highlighted as potential treatment to control excessive innate immune responses during mucosal inflammation.

Reduced atherosclerosis lesion size, inflammatory response in miR-150 knockout mice via macrophage effects

Atherosclerosis is considered to be a chronic inflammatory disease that can lead to severe clinically important cardiovascular events. miR-150 is a small noncoding RNA that significantly enhances inflammatory responses by upregulating endothelial cell proliferation and migration, as well as intravascular environmental homeostasis. However, the exact role of miR-150 in atherosclerosis remains unknown. Here, we investigated the effect of miR-150 deficiency on atherosclerosis development. Using double-knockout (miR-150^-/- and ApoE^-/-) mice, we measured atherosclerotic lesion size and stability. Meanwhile, we conducted in vivo bone marrow transplantation to identify cellular-level components of the inflammatory response. Compared with mice deficient only in ApoE, the double-knockout mice had significantly smaller atherosclerotic lesions and displayed an attenuated inflammatory response. Moreover, miR-150 ablation promoted plaque stabilization via increases in smooth muscle cell and collagen content and decreased macrophage infiltration and lipid accumulation. The in vitro experiments indicated that an inflammatory response with miR-150 deficiency in atherosclerosis results directly from upregulated expression of the cytoskeletal protein, PDZ and LIM domain 1 (PDLIM1), in macrophages. More importantly, the decreases in phosphorylated p65 expression and inflammatory cytokine secretion induced by miR-150 ablation were reversed by PDLIM1 knockdown. These findings suggest that miR-150 is a promising target for the management of atherosclerosis.