MicroRNAs and apoptosis: implications in the molecular therapy of human disease

Small molecule and big function: MicroRNA-mediated apoptosis in rheumatoid arthritis

Rheumatoid arthritis (RA) is a common autoimmune condition and chronic inflammatory disease, mostly affecting synovial joints. The complex pathogenesis of RA is supportive of high morbidity, disability, and mortality rates. Pathological changes a common characteristic in RA synovial tissue is attributed to the inadequacy of apoptotic pathways. In that regard, apoptotic pathways have been the center of attention in RA therapeutic approaches. As the regulators in the complex network of apoptosis, microRNAs (miRNAs) are found to be vital modulators in both intrinsic and extrinsic pathways through altering their regulatory genes. Indeed, miRNA, a member of the family of non-coding RNAs, are found to be an important player in not even apoptosis, but proliferation, gene expression, signaling pathways, and angiogenesis. Aberrant expression of miRNAs is implicated in attenuation and/or intensification of various apoptosis routes, resulting in culmination of human diseases including RA. Considering the need for more studies focused on the underlying mechanisms of RA in order to elevate the unsatisfactory clinical treatments, this study is aimed to delineate the importance of apoptosis in the pathophysiology of this disease. As well, this review is focused on the critical role of miRNAs in inducing or inhibiting apoptosis of RA-synovial fibroblasts and fibroblast-like synoviocytes and how this mechanism can be exerted for therapeutic purposes for RA.

miR-92a-3p promotes pulmonary fibrosis progression by regulating KLF2-mediated endothelial-to-mesenchymal transition

Pulmonary fibrosis (PF) is a chronic lung disease that has a poor prognosis and a serious impact on the quality of life of patients. Here, we investigated the potential role of miR-92a-3p in PF. The mRNA level of miR-92a-3p was significantly increased in both the lung tissues of bleomycin (BLM)--treated mice and pulmonary microvascular endothelial cells (PMVECs). Overexpressing miR-92a-3p increased the mRNA and protein levels of α‑SMA, vimentin, and Col-1 but downregulated E-cadherin. Additionally, the protein and mRNA expression levels of KLF2 were significantly decreased in the lung tissues of BLM-treated mice, suggesting that KLF2 participated in the progression of BLM-induced PF. Downregulating miR-92a-3p upregulated the expression of KLF2 and inhibited the endothelial-to-mesenchymal transition (EndoMT) process, thus alleviating PF in vivo. Altogether, a miR-92a-3p deficiency could significantly reduce the development of myofibroblasts and ameliorate PF progression.

microRNAs, oxidative stress, and genotoxicity as the main inducers in the pathobiology of cancer development

Cancer is one of the most serious leading causes of death in the world. Many eclectic factors are involved in cancer progression including genetic and epigenetic alongside environmental ones. In this account, the performance and fluctuations of microRNAs are significant in cancer diagnosis and treatment, particularly as diagnostic biomarkers in oncology. So, microRNAs manage and control the gene expression after transcription by mRNA degradation, or also they can inhibit their translation. Conspicuously, these molecular structures take part in controlling the cellular, physiological and pathological functions, which many of them can accomplish as tumor inhibitors or oncogenes. Relatively, Oxidative stress is defined as the inequality between the creation of reactive oxygen species (ROS) and the body's ability to detoxify the reactive mediators or repair the resulting injury. ROS and microRNAs have been recognized as main cancer promoters and possible treatment targets. Importantly, genotoxicity has been established as the primary reason for many diseases as well as several malignancies. The procedures have no obvious link with mutagenicity and influence the organization, accuracy of the information, or fragmentation of DNA. Conclusively, mutations in these patterns can lead to carcinogenesis. In this review article, we report the impressive and practical roles of microRNAs, oxidative stress, and genotoxicity in the pathobiology of cancer development in conjunction with their importance as reliable cancer biomarkers and their association with circulating miRNA, exosomes and exosomal miRNAs, RNA remodeling, DNA methylation, and other molecular elements in oncology.

MicroRNA‑378: An important player in cardiovascular diseases (Review)

Cardiovascular disease (CVD) is a common chronic clinical condition and is the main cause of death in humans worldwide. Understanding the genetic and molecular mechanisms involved in the development of CVD is essential to develop effective prevention strategies and therapeutic measures. An increasing number of CVD‑related genetic studies have been conducted, including those on the potential roles of microRNAs (miRs). These studies have demonstrated that miR‑378 is involved in the pathological processes of CVD, including those of myocardial infarction, heart failure and coronary heart disease. Despite the potential importance of miR‑378 CVD, a comprehensive summary of the related literature is lacking. Thus, the present review aimed to summarize the findings of previous studies on the roles and mechanisms of miR‑378 in a variety of CVDs and provide an up‑to date basis for further r research targeting the prevention and treatment of CVDs.

Understanding the Pathogenesis of Cardiac Complications in Patients with Propionic Acidemia and Exploring Therapeutic Alternatives for Those Who Are Not Eligible or Are Waiting for Liver Transplantation

The guidelines for the management of patients affected by propionic acidemia (PA) recommend standard cardiac therapy in the presence of cardiac complications. A recent revision questioned the impact of high doses of coenzyme Q10 on cardiac function in patients with cardiomyopathy (CM). Liver transplantation is a therapeutic option for several patients since it may stabilize or reverse CM. Both the patients waiting for liver transplantation and, even more, the ones not eligible for transplant programs urgently need therapies to improve cardiac function. To this aim, the identification of the pathogenetic mechanisms represents a key point. Aims: This review summarizes: (1) the current knowledge of the pathogenetic mechanisms underlying cardiac complications in PA and (2) the available and potential pharmacological options for the prevention or the treatment of cardiac complications in PA. To select articles, we searched the electronic database PubMed using the Mesh terms "propionic acidemia" OR "propionate" AND "cardiomyopathy" OR "Long QT syndrome". We selected 77 studies, enlightening 12 potential disease-specific or non-disease-specific pathogenetic mechanisms, namely: impaired substrate delivery to TCA cycle and TCA dysfunction, secondary mitochondrial electron transport chain dysfunction and oxidative stress, coenzyme Q10 deficiency, metabolic reprogramming, carnitine deficiency, cardiac excitation-contraction coupling alteration, genetics, epigenetics, microRNAs, micronutrients deficiencies, renin-angiotensin-aldosterone system activation, and increased sympathetic activation. We provide a critical discussion of the related therapeutic options. Current literature supports the involvement of multiple cellular pathways in cardiac complications of PA, indicating the growing complexity of their pathophysiology. Elucidating the mechanisms responsible for such abnormalities is essential to identify therapeutic strategies going beyond the correction of the enzymatic defect rather than engaging the dysregulated mechanisms. Although these approaches are not expected to be resolutive, they may improve the quality of life and slow the disease progression. Available pharmacological options are limited and tested in small cohorts. Indeed, a multicenter approach is mandatory to strengthen the efficacy of therapeutic options.

The Role of miR-155 in Antitumor Immunity

MicroRNAs belong to a group of short non-coding RNA molecules that are involved in the regulation of gene expression at multiple levels. Their function was described two decades ago, and, since then, microRNAs have become a rapidly developing field of research. Their participation in the regulation of cellular processes, such as proliferation, apoptosis, cell growth, and migration, made microRNAs attractive for cancer research. Moreover, as a single microRNA can simultaneously target multiple molecules, microRNAs offer a unique advantage in regulating multiple cellular processes in different cell types. Many of these cell types are tumor cells and the cells of the immune system. One of the most studied microRNAs in the context of cancer and the immune system is miR-155. MiR-155 plays a role in modulating innate and adaptive immune mechanisms in distinct immune cell types. As such, miR-155 can be part of the communication between the tumor and immune cells and thus impact the process of tumor immunoediting. Several studies have already revealed its effect on antitumor immune responses, and the targeting of this molecule is increasingly implemented in cancer immunotherapy. In this review, we discuss the current knowledge of miR-155 in the regulation of antitumor immunity and the shaping of the tumor microenvironment, and the plausible implementation of miR-155 targeting in cancer therapy.

Expression of Apoptosis-Related Biomarkers in Inflamed Nasal Sinus Epithelium of Patients with Chronic Rhinosinusitis with Nasal Polyps (CRSwNP)—Evaluation at mRNA and miRNA Levels

In chronic upper respiratory tract diseases, increased cell proliferative activity is observed, which is coordinated by BCL-2 proteins and small non-coding RNAs. This study aimed to determine the expression of critical apoptosis markers at the mRNA and miRNA levels in patients with chronic rhinosinusitis with nasal polyps (CSRwNP). The study group consisted of ten patients with CSRwNP and ten healthy subjects. To detect in situ apoptosis in the maxillary sinus mucosa, TUNEL staining was performed. The expression of transcripts was determined by RT-qPCR and included the detection of markers associated with cell survival and apoptosis, i.e., BAX, p53, p21, CASP3, CASP9, c-MYC, CCND1, BRIC5, and APAF1. Levels of miR-17-5p, miR-145-5p, miR-146a-5p, and miR-203a-3p were also measured by RT-qPCR. The obtained results indicated increased apoptosis determined by a TUNEL assay in CSRwNP patients and accompanied by an increased expression of BAX, P21, P53, CASP3, CASP9, c-MYC, and APAF-1 transcripts and decreased mRNA levels of BCL-2 and BIRC5. Furthermore, the nasal sinus epithelium of patients with CSRwNP showed increased levels of miR-203a-3p while also showing a decreased expression of miR-17-5p and miR-145-5p. Our results showed that pro-apoptotic transcripts detected at mRNA and miRNA levels might be involved in the pathogenesis of chronic sinusitis with polyps. The identification of those key molecular mediators may be applicable for the specific diagnostic and/or development of targeted therapies for chronic sinusitis with polyps.

Transcriptional Profiles of Cell Fate Transitions Reveal Early Drivers of Neuronal Apoptosis and Survival

Neuronal apoptosis and survival are regulated at the transcriptional level. To identify key genes and upstream regulators primarily responsible for these processes, we overlayed the temporal transcriptome of cerebellar granule neurons following induction of apoptosis and their rescue by three different neurotrophic factors. We identified a core set of 175 genes showing opposite expression trends at the intersection of apoptosis and survival. Their functional annotations and expression signatures significantly correlated to neurological, psychiatric and oncological disorders. Transcription regulatory network analysis revealed the action of nine upstream transcription factors, converging pro-apoptosis and pro-survival-inducing signals in a highly interconnected functionally and temporally ordered manner. Five of these transcription factors are potential drug targets. Transcriptome-based computational drug repurposing produced a list of drug candidates that may revert the apoptotic core set signature. Besides elucidating early drivers of neuronal apoptosis and survival, our systems biology-based perspective paves the way to innovative pharmacology focused on upstream targets and regulatory networks.

The Regulatory Effect of MicroRNA-101-3p on Disc Degeneration by the STC1/VEGF/MAPK Pathway

Aims. Accumulating evidence reported that the microRNA (miRNA) took an important role in intervertebral disc degeneration (IDD). In this study, we revealed a novel miRNA regulatory mechanism in IDD. Main Methods. The miRNA microarray analyses of human degenerated and normal disc samples were employed to screen out the target miRNA. In vitro and in vivo experiments were conducted to verify the regulatory effect of miR-101-3p. Key Findings. The expression level of miR-101-3p was significantly decreased in the degenerated disc samples which were confirmed by qRT-PCR. Moreover, the miR-101-3p expression level was changed dynamically according to the disc degeneration grade. Upregulation of miR-101-3p expression level inhibited cell apoptosis. Furthermore, stanniocalcin-1 (STC1) was selected to be the target gene of miR-101-3p according to the bioinformatic algorithms. Mechanically, upregulation of miR-101-3p significantly decreased the expression of STC1, vascular endothelial growth factor (VEGF), and MAPK pathway expression levels. Therapeutically, in vivo experiment on IDD rat model illustrated that agomir-101-3p could effectively suspend IDD. Significance. Our findings demonstrated that miR-101-3p alleviated IDD process through the STC1/VEGF/MAPK pathway.

Clinical impact of serum exosomal microRNA in liver fibrosis

BACKGROUND/AIM

We investigated alterations in the expression of serum exosomal miRNAs with the progression of liver fibrosis and evaluated their clinical applicability as biomarkers.

METHODS

This study prospectively enrolled 71 patients who underwent liver biopsy at an academic hospital in Korea. Exosomes were extracted from serum samples, followed by next-generation sequencing (NGS) of miRNAs and targeted real-time quantitative polymerase chain reaction. A model was derived to discriminate advanced fibrosis based on miRNA levels and the performance of this model was evaluated. Validation of the effect of miRNA on liver fibrosis in vitro was followed.

RESULTS

NGS data revealed that exosomal miR-660-5p, miR-125a-5p, and miR-122 expression were changed significantly with the progression of liver fibrosis, of which miR-122 exhibited high read counts enough to be used as a biomarker. The level of exosomal miR-122 decreased as the pathologic fibrosis grade progressed and patients with biopsy-proven advanced fibrosis had significantly lower levels of exosomal miR-122 (P < 0.001) than those without advanced fibrosis. Exosomal miR-122 exhibited a fair performance in discriminating advanced fibrosis especially in combination with fibrosis-4 score and transient elastography. In a subgroup of patients with a non-viral etiology of liver disease, the performance of exosomal miR-122 as a biomarker was greatly improved. Inhibition of miR-122 expression increased the proliferation of the human hepatic stellate cell line, LX-2, and upregulated the expression of various fibrosis related proteins.

CONCLUSION

Exosomal miR-122 may serve as a useful non-invasive biomarker for liver fibrosis, especially in patients with non-viral etiologies of chronic liver disease.

miR-182-5p Serves as an Oncogene in Lung Adenocarcinoma through Binding to STARD13

Lung cancer as one of the commonest invasive malignancies is featured by high morbidity and mortality, wherein lung adenocarcinoma (LUAD) is the most prevalent subtype. Accumulating evidence exhibited that microRNAs are involved in LUAD occurrence and progression. In this study, miR-182-5p was observed to increase in both LUAD tissue and cell lines. Overexpression of miR-182-5p could prominently facilitate cell proliferation, migration, and invasion in LUAD. Through bioinformatics analysis, STARD13 was theorized as the target gene of miR-182-5p, which was lowly expressed in LUAD. Further molecular experiments manifested that miR-182-5p bound to the 3'-untranslated region of STARD13, and there was an inverse correlation between STARD13 and miR-182-5p in LUAD. Rescue experiments demonstrated that silencing STARD13 conspicuously restored the inhibitory effect of decreased miR-182-5p on cell proliferation, migration, and invasion in LUAD. Together, our findings revealed novel roles of the miR-182-5p/STARD13 axis in LUAD progression.

Circular RNA circHIPK3 promotes breast cancer progression via sponging MiR-326

Background: This study investigated the potential molecular mechanism of circular RNA HIPK3 (circHIPK3) in breast cancer (BCa). Methods: BCa cells were transfected with miR-326 mimic, miR-326 inhibitor, circHIPK3, sicircHIPK3. The expressions of circHIPK3 and miR-326 in BCa tissues and BCa cell lines were determined by RT-qPCR. Cell viability, colony formation, migration, invasion, and apoptosis of the cells were detected by CCK-8 and colony formation, wound-healing, transwell and flow cytometric assays, respectively. The relationship between circHIPK3 and miR-326 was analyzed and confirmed by circInteractome, dual-luciferase reporter, RT-qPCR, Pearson's correlation assays. Western blot and RT-qPCR were performed to determine the expressions of apoptosis-related molecules (Bcl-2, Bax, and cleaved Caspase-3) and EMT-related molecules (E-cadherin, N-cadherin, and Vimentin) in the BCa cells and tumor tissues. The tumor growth in mice was examined in a xenograft tumor model in which Ki-67 expression was determined by immunohistochemistry (IHC). Results: In BCa, the expression of circHIPK3 was up-regulated and that of miR-326 was down-regulated. CircHIPK3 knockdown inhibited the cell proliferation, invasion, and migration. MiR-326 was the direct target of circHIPK3, and was inversely correlated with circHIPK3 expression. CircHIPK3 overexpression promoted proliferation, migration, invasion, apoptosis resistance, and tumor growth and up-regulated Ki-67 expression, at the same time, the expressions of Bcl-2, N-cadherin, Vimentin were up-regulated, and those of Bax, cleaved Caspase-3 and E-cadherin were inhibited. These above expressions were partially reversed by miR-326 overexpression. Conclusion: CircHIPK3 sponges miR-326 to promote BCa growth and metastasis. The current findings provide a novel therapeutic target for treating BCa.

MiR-340 Promotes the Proliferation of Vascular Smooth Muscle Cells by Targeting von Hippel-Lindau Tumor Suppressor Gene

ABSTRACT

MiRNAs play key roles in the proliferation of vascular smooth muscle cells (VSMCs). However, the roles and underlying mechanism of miRNAs in VSMCs are not fully understood. The aim of this study was to evaluate the role of miR-340 in the proliferation of VSMCs. The expression levels of miR-340 and von Hippel-Lindau tumor suppressor (VHL) in VSMCs induced by platelet-derived growth factor-BB or fetal bovine serum were measured by q-polymerase chain reaction. The effects of miR-340 and VHL on cell proliferation and invasion were evaluated by CCK-8 assay. Target gene prediction and screening as well as luciferase reporter assay were performed to verify the downstream target genes of miR-340. Western blotting was used to detect the protein expression levels of vascular endothelial growth factor and VHL. Our results showed that the miR-340 was upregulated in platelet-derived growth factor-BBor fetal bovine serum-induced VSMCs. In addition, overexpression of miR-340 promoted VSMCs proliferation and invasion. Moreover, VHL was found to be a potential target for miR-340 and upregulation of VHL-inhibited VSMCs proliferation. MiR-340 plays a critical role in VSMC proliferation and neointimal hyperplasia in rats' carotid balloon injury model. Reduced expression levels of miR-340 promoted VHL-inhibited VSMCs proliferation. In conclusion, miR-340 may play a role in the regulation of proliferation of VSMCs by inhibition of VHL.

Quercetin, Perillyl Alcohol, and Berberine Ameliorate Right Ventricular Disorders in Experimental Pulmonary Arterial Hypertension: Effects on miR-204, miR-27a, Fibrotic, Apoptotic, and Inflammatory Factors

ABSTRACT

Pulmonary arterial hypertension (PAH) is a pulmonary vascular disease causing right ventricular (RV) hypertrophy, failure, and death. Some miRNAs are involved in the pathophysiology of PAH. As the current treatments cannot prevent the progression of the disease, we investigated whether 3 plant derivatives, namely perillyl alcohol (PA), quercetin (QS), and berberine (BBR), can improve RV function and affect the expression of miR-204, miR-27a, and biochemical factors in monocrotaline-induced PAH (MCT-PAH). Thirty-six rats were divided into control (CTL), MCT, MCT+Veh (vehicle), MCT+PA, MCT+QS, and MCT + BBR groups (n = 6 each). After inducing PAH using MCT (60 mg/kg), PA (50 mg/kg), QS (30 mg/kg), and BBR (30 mg/kg) were administrated daily for 3 weeks. miR-204 expression, total antioxidant capacity, and antiapoptotic protein Bcl-2 significantly declined in the RV of PAH rats, and PA, QS, and BBR treatment significantly compensated for these decreases. Proapoptotic protein Bax and p21 cell cycle inhibitor increased in the RV. All 3 herbal derivatives compensated for Bax increase, and BBR caused a decrease in p21. TNFα, IL-6, and malondialdehyde increased in the RV, and PA, QS, and BBR significantly counterbalanced these increases. miR-27a expression was not affected by MCT and plant derivatives. Overall, PA, QS, and BBR improved ventricular disorders in rats with PAH by decreasing inflammation, apoptosis, and fibrosis and increasing the antioxidant-to-oxidant ratio. Therefore, these herbal derivatives may be considered as target therapeutic goals for this disease either alone or in combination with current medications.

Lactobacillus Plantarum 299v Changes miRNA Expression in the Intestines of Piglets and Leads to Downregulation of LITAF by Regulating ssc-miR-450a

Lactiplantibacillus plantarum subsp. plantarum 299v (L. plantarum 299v) is one of the most important probiotic strains in animal health, but the molecular mechanisms of how it exerts health benefits remain unclear. The purpose of this study was to explore the changes in miRNA expression profiles in the intestinal tissues of piglets by L. plantarum 299v and to explore its possible molecular regulatory mechanism in intestinal function. Neonatal piglets were orally administered L. plantarum 299v daily from 1 to 20 days old, and high-throughput sequencing was conducted to analyse the changes in miRNA expression in the jejunum and ileum. The results showed that 370 known porcine miRNAs were identified from eight libraries. Five miRNAs (ssc-miR-21-5p, -143-3p, -194b-5p, -192, and -126-3p) were highly expressed in the intestinal tissues. There were 15 differentially expressed miRNAs between the control group and the L. plantarum group, and only miR-450a was expressed differentially in both intestinal tissues. KEGG analysis revealed that the target genes of the 15 differentially expressed miRNAs were involved in 37 significantly enriched pathways (P < 0.01). Then, quantitative polymerase chain reaction confirmed that the miRNA expression was corresponded well with those from the sequencing. Luciferase reporter assays verified that lipopolysaccharide-induced TNF-α factor is a target of miR-450a. Our results also showed L. plantarum 299v could influence intestinal function by changing the levels of cytokines via miRNA expression. This is the first study to analyse differential expression miRNA profiles in intestinal tissue after L. plantarum 299v treatment and investigate the molecular regulatory mechanism of functional miRNA.

Health-Promoting Effects of Thymus Phenolic-Rich Extracts: Antioxidant, Anti-Inflammatory and Antitumoral Properties

Thymus genus comprises numerous species that are particularly abundant in the West Mediterranean region. A growing body of evidence suggests that many of these species are a rich source of bioactive compounds, including phenolic compounds such as rosmarinic acid, salvianolic acids and luteolin glycosides, able to render them potential applications in a range of industrial fields. This review collects the most relevant studies focused on the antioxidant, anti-inflammatory and anti-cancer of phenolic-rich extracts from Thymus plants, highlighting correlations made by the authors with respect to the main phenolic players in such activities.

Angiotensin-(1-9) prevents cardiomyocyte hypertrophy by controlling mitochondrial dynamics via miR-129-3p/PKIA pathway

Angiotensin-(1-9) is a peptide from the noncanonical renin-angiotensin system with anti-hypertrophic effects in cardiomyocytes via an unknown mechanism. In the present study we aimed to elucidate it, basing us initially on previous work from our group and colleagues who proved a relationship between disturbances in mitochondrial morphology and calcium handling, associated with the setting of cardiac hypertrophy. Our first finding was that angiotensin-(1-9) can induce mitochondrial fusion through DRP1 phosphorylation. Secondly, angiotensin-(1-9) blocked mitochondrial fission and intracellular calcium dysregulation in a model of norepinephrine-induced cardiomyocyte hypertrophy, preventing the activation of the calcineurin/NFAT signaling pathway. To further investigate angiotensin-(1-9) anti-hypertrophic mechanism, we performed RNA-seq studies, identifying the upregulation of miR-129 under angiotensin-(1-9) treatment. miR-129 decreased the transcript levels of the protein kinase A inhibitor (PKIA), resulting in the activation of the protein kinase A (PKA) signaling pathway. Finally, we showed that PKA activity is necessary for the effects of angiotensin-(1-9) over mitochondrial dynamics, calcium handling and its anti-hypertrophic effects.

Inhibition of miR-182-5p attenuates pulmonary fibrosis via TGF-β/Smad pathway

Idiopathic pulmonary fibrosis (IPF) is a chronic and progressive lung disease with high morbidity and mortality. miR-182-5p is overexpressed in several fibrosis-related diseases but its effect in pulmonary fibrosis has not been reported yet. To investigate the function of miR-182-5p in pulmonary fibrosis, we established bleomycin (BLM)-induced fibrotic mice model and transforming growth factor-β1 (TGF-β1)-treated human embryonic lung fibroblasts model. In this study, miR-182-5p was highly expressed in pulmonary tissues of BLM-induced fibrotic mice. The content of hydroxyproline and TGF-β1 was decreased by downregulating the expression of miR-182-5p, indicating that fibrosis was alleviated in mice treated with Lentivirus-anti-miR-182-5p.Quantification of fibrosis-related proteins demonstrated that downregulation of miR-182-5p inhibited the expression of profibrotic proteins (fibronectin, α-smooth muscle actin, p-Smad2/p-Smad3) as well as enhanced the level of Smad7. In vitro assays validated that miR-182-5p was induced by TGF-β1 with the function of promoting fibrosis. In dual-luciferase reporter assay, Smad7 was demonstrated to be negatively regulated by miR-182-5p. Moreover, the effect of knocking down miR-182-5p on inhibiting fibrosis was achieved by upregulating the expression of Smad7. Therefore, miR-182-5p can be regarded as a biomarker of IPF and its inhibition may be a promising therapeutic approach in treating IPF.

DNA methylation, microRNA expression profiles and their relationships with transcriptome in grass-fed and grain-fed Angus cattle rumen tissue

Rumen is an organ for supplying nutrients for the growth and production of bovine, which might function differently under grass-fed and grain-fed regimens considering the association of gene expression, DNA methylation, and microRNA expression. The objective of this study was to explore the potential mechanism influencing rumen function of grass-fed and grain-fed animals. Methylated DNA binding domain sequencing (MBD-Seq) and microRNA-Seq were respectively utilized to detect the DNA methylation and microRNA expression in rumen tissue of grass-fed and grain-fed Angus cattle. Combined analysis revealed that the expression of the differentially expressed genes ADAMTS3 and ENPP3 was correlated with the methylation abundance of the corresponding differentially methylated regions (DMRs) inside these two genes, and these two genes were reported to be respectively involved in biosynthesis and regulation of glycosyltransferase activity; the differentially expressed microRNA bta-mir-122 was predicted to possibly target the differentially expressed genes OCLN and RBM47, potentially affecting the rumen function; the microRNA bta-mir-655 was exclusively detected in grain-fed group; its targets were significantly enriched in insulin and TGF-beta signaling pathways, which might worked together to regulate the function of rumen, resulting in different characteristics between grass-fed and grain-fed cattle. Collectively, our results provided insights into understanding the mechanisms determining rumen function and unraveled the biological basis underlying the economic traits to improve the productivity of animals.

MiR-184 Retarded the Proliferation, Invasiveness and Migration of Glioblastoma Cells by Repressing Stanniocalcin-2

To investigate the repression of miR-184 on Stanniocalcin-2 (STC2) and how this axis affects the propagation, invasiveness and migration ability of glioblastoma cells. RT-PCR was employed to determine the miR-184 and STC2 mRNA expression both in tissues and cells. Western blot was employed to determine the protein expression levels. The cells were transfected via lipofection. MTT, colony formation, invasion and scratch healing assays were conducted to study the propagation, invasiveness and migratory ability of glioblastoma cells, respectively. The dual luciferase reporter gene assay was conducted to determine whether miR-184 could directly bind to STC2 mRNA 3'UTR. MiR-184 was under-expressed whereas STC2 was over-expressed in glioblastoma tissues and cell line. The up-regulation of miR-184 significantly suppressed the propagation, migratory ability and invasion of glioblastoma cells, whereas the over-expression of STC2 restored this effect. MiR-184 was confirmed to directly target STC2. MiR-184 could retard the propagation, invasiveness and migratory ability of glioblastoma cells by suppressing STC2.

MicroRNA-326 aggravates acute lung injury in septic shock by mediating the NF-κB signaling pathway

Our previous studies have demonstrated that the activation of the nuclear factor-kappa B (NF-κB) signaling pathway contributes to the development of lipopolysaccharide (LPS)-induced acute lung injury (ALI) as well as an inflammatory reaction, and its inhibition may provide future therapeutic values. Thereby, this study aims to explore the effects of miR-326 on inflammatory response and ALI in mice with septic shock via the NF-κB signaling pathway. The study included normal mice and LPS-induced mouse models of septic shock with ALI. Modeled mice were transfected with the blank plasmid, miR-326 mimic, miR-326 inhibitor, si-BCL2A1 and miR-326 inhibitor + si-BCL2A1. Mean arterial pressure (MAP), airway pressure (AP), heart rate (HR) and lung wet dry (W/D) ratio were determined. Serum levels of interleukin (IL)-6, IL-10, IL-1β, and tumor necrosis factor-α (TNF-α) were detected using ELISA. Reverse transcription quantitative polymerase chain reaction (RT-qPCR) and Western blot analysis were performed to detect the miR-326 expression and expression levels of BCL2A1, related genes of inflammatory response and the NF-κB signaling pathway in lung tissues. Cell viability and apoptosis were measured using the CCK-8 assay and flow cytometry, respectively. Compared to the ALI models and those transfected with blank plasmid, the up-regulated miR-326 expression and silenced BCL2A1 lead to decreased levels of MAP, increased AP, HR and lung W/D, increased serum levels of IL-6, IL-10, IL-1β and TNF-α, increased expressions of IL-6, IL-1β, TNF-α, NF-κB p65 (p-NF-κB p65), and iNOS with decreased expressions of BCL2A1s as well as inhibition of cell viability and enhanced cell apoptosis; the down-regulated miR-326 expression reversed the aforementioned situation. MiR-326 targeting the BCL2A1 gene activated the NF-κB signaling pathway, resulting in aggravated inflammatory response and lung injury of septic shock with ALI in mice.

Dysregulated miRNAs and their pathogenic implications for the neurometabolic disease propionic acidemia

miRNome expression profiling was performed in a mouse model of propionic acidemia (PA) and in patients’ plasma samples to investigate the role of miRNAs in the pathophysiology of the disease and to identify novel biomarkers and therapeutic targets. PA is a potentially lethal neurometabolic disease with patients developing neurological deficits and cardiomyopathy in the long-term, among other complications. In the PA mouse liver we identified 14 significantly dysregulated miRNAs. Three selected miRNAs, miR-34a-5p, miR-338-3p and miR-350, were found upregulated in brain and heart tissues. Predicted targets involved in apoptosis, stress-signaling and mitochondrial function, were inversely found down-regulated. Functional analysis with miRNA mimics in cellular models confirmed these findings. miRNA profiling in plasma samples from neonatal PA patients and age-matched control individuals identified a set of differentially expressed miRNAs, several were coincident with those identified in the PA mouse, among them miR-34a-5p and miR-338-3p. These two miRNAs were also found dysregulated in childhood and adult PA patients’ cohorts. Taken together, the results reveal miRNA signatures in PA useful to identify potential biomarkers, to refine the understanding of the molecular mechanisms of this rare disease and, eventually, to improve the management of patients.

microRNA let-7c is essential for the anisomycin-elicited apoptosis in Jurkat T cells by linking JNK1/2 to AP-1/STAT1/STAT3 signaling

Anisomycin, an antibiotic produced by Streptomyces griseolus, strongly induces apoptosis in various tumor cells in vitro, superior dramatically to adriamycin. The present study aims to elucidate its detailed mechanistic process. The results showed that anisomycin sufficiently promoted the apoptosis in human leukemic Jurkat T cells at a quite low dose. microRNA let-7c (let-7c) contributed to the anisomycin-induced apoptosis, which could be abrogated by the inactivation of JNK signaling. The let-7c over-expression and the addition of its mimics facilitated the activation of AP-1, STAT1 and Bim by linking JNK1/2 to AP-1/STAT1, but rather inhibited the activation of STAT3 and Bcl-xL by connecting JNK1/2 to STAT3, followed by the augmented apoptosis in the cells. The let-7c deficiency reduced the AP-1, STAT1 and Bim activities, and enhanced the STAT3 and Bcl-xL, alleviating the anisomycin-induced apoptosis. The knockdown of the bim gene repressed the anisomycin-boosted apoptosis through the attenuation of the active Bak and Bax. The findings indicate for the first time that miR let-7c is essential for the anisomycin-triggered apoptosis by linking JNK1/2 to AP-1/STAT1/STAT3/Bim/Bcl-xL/Bax/Bak signaling. This provides a novel insight into the mechanism by which anisomycin leads to the tumor cell apoptosis, potentially laying the foundations for its development and clinical application.

miR-9-5p suppresses pro-fibrogenic transformation of fibroblasts and prevents organ fibrosis by targeting NOX4 and TGFBR2

Uncontrolled extracellular matrix (ECM) production by fibroblasts in response to injury contributes to fibrotic diseases, including idiopathic pulmonary fibrosis (IPF). Reactive oxygen species (ROS) generation is involved in the pathogenesis of IPF. Transforming growth factor-β1 (TGF-β1) stimulates the production of NADPH oxidase 4 (NOX4)-dependent ROS, promoting lung fibrosis (LF). Dysregulation of microRNAs (miRNAs) has been shown to contribute to LF. To identify miRNAs involved in redox regulation relevant for IPF, we performed arrays in human lung fibroblasts exposed to ROS. miR-9-5p was selected as the best candidate and we demonstrate its inhibitory effect on TGF-β receptor type II (TGFBR2) and NOX4 expression. Increased expression of miR-9-5p abrogates TGF-β1-dependent myofibroblast phenotypic transformation. In the mouse model of bleomycin-induced LF, miR-9-5p dramatically reduces fibrogenesis and inhibition of miR-9-5p and prevents its anti-fibrotic effect both in vitro and in vivo. In lung specimens from patients with IPF, high levels of miR-9-5p are found. In omentum-derived mesothelial cells (MCs) from patients subjected to peritoneal dialysis (PD), miR-9-5p also inhibits mesothelial to myofibroblast transformation. We propose that TGF-β1 induces miR-9-5p expression as a self-limiting homeostatic response.

Propofol-induced rno-miR-665 targets BCL2L1 and influences apoptosis in rodent developing hippocampal astrocytes

Propofol exerts neurotoxic effects on the developing mammalian brains, but the underlying molecular mechanism remains unclear. MicroRNAs (miRNAs) are a class of small noncoding RNAs that modulate gene expression at the post-transcriptional level. However, in specific types of neurocytes, the detailed functions of miRNAs were not entirely understood. We investigated the potential role of miRNAs in astrocyte pathogenesis caused by propofol. We performed genome-wide microRNA expression profiling in immature cultured hippocampal astrocytes by microarray analysis and predicted their targets and functions using bioinformatics tools. The functional effects of one differentially expressed miRNA were examined experimentally in relation to astrocyte viability. The results showed that 13 miRNAs were significantly differentially expressed after both short-term exposure to high-concentration propofol (10 μg/ml for 1h) and long-term exposure to low-concentration propofol (0.9 μg/ml for 48 h), including rno-miR-665, differing significantly between the 2. Bioinformatics predicted putative binding sites for rno-miR-665 existing in the 3'-untranslated region of Bcl-2-like protein 1 BCL2L1 (Bcl-xl) mRNA. Moreover, such relationship was assessed by luciferase reporter assay, qRT-PCR and western blot. Rno-miR-665 which was significantly up-regulated by propofol can suppress BCL2L1 and elevate cleaved caspase-3 expression in immature astrocytes in vitro. Apoptosis of developing hippocampal astrocytes was thus significantly influenced by propofol or rno-miR-665, or both. Taken together, rno-miR-665 is involved in the neurotoxicity induced by propofol via a caspase-3 mediated mechanism by negatively regulating BCL2L1. It might act as an alternative therapeutic target for treatment of neurological disorders in peadiatric prolonged anesthesia or sedation with propofol clinically.

Significance of serum and hepatic microRNA-122 levels in patients with non-alcoholic fatty liver disease

BACKGROUND & AIMS

Non-alcoholic fatty liver disease (NAFLD) is believed to be a type of metabolic syndrome. MicroRNA-122 (miR-122) is the most abundant microRNA in the liver and is an important factor for the metabolism of glucose and lipids. In the present study, we examined the correlation between the hepatic and serum miR-122 expression levels and the clinicopathological factors of patients with NAFLD.

METHODS

We extracted the total RNA, along with preserved miRNAs, from liver biopsy samples of 67 patients with NAFLD. In 52 of these 67 patients, the total RNA was extracted from serum. The miR-122 that was obtained by quantitative reverse transcription-polymerase chain reaction was quantified using TaqMan MicroRNA assays.

RESULTS

A significant correlation was detected between serum and hepatic miR-122 expression (correlation coefficient, 0.461; P=0.005). Patients with mild steatosis (<33%) showed significantly lower levels of hepatic miR-122 compared with patients with severe steatosis (>33%) (hepatic miR-122: mild/severe=2.158±1.786/4.836±7.506, P=0.0473; serum miR-122: mild/severe=0.002±0.005/0.007±0.001, P=0.0491). Moreover, hepatic and serum miR-122 levels were significantly higher in patients with mild fibrosis than in those with severe fibrosis (hepatic miR-122: mild/severe=5.201±7.275/2.394±1.547, P=0.0087; serum miR-122: mild/severe=0.008±0.011/0.002±0.004, P=0.0191).

CONCLUSIONS

We found that the hepatic and serum miR-122 levels were associated with hepatic steatosis and fibrosis. The serum miR-122 level can be a useful predictive marker of liver fibrosis in patients with NAFLD.

miR-15b suppression of Bcl-2 contributes to cerebral ischemic injury and is reversed by sevoflurane preconditioning

Ischemic neuroprotection afforded by sevoflurane preconditioning has been previously demonstrated, yet the underlying mechanism is poorly understood and likely affects a wide range of cellular activities. Several individual microRNAs have been implicated in both the pathogenesis of cerebral ischemia and cellular survival, and are capable of affecting a range of target mRNA. Conceivably, sevoflurane preconditioning may lead to alterations in ischemia-induced microRNA expression that may subsequently exert neuroprotective effects. We first examined the microRNA expression profile following transient cerebral ischemia in rats and the impact of sevoflurane preconditioning. Microarray analysis revealed that 3 microRNAs were up-regulated (>2.0 fold) and 9 were down-regulated (< 0.5 fold) following middle cerebral artery occlusion (MCAO) compared to sham controls. In particular, miR-15b was expressed at significantly high levels after MCAO. Preconditioning with sevoflurane significantly attenuated the upregulation of miR-15b at 72h after reperfusion. Bcl-2, an anti-apoptotic gene involved in the pathogenesis of cerebral ischemia, has been identified as a direct target of miR-15b. Consistent with the observed downregulation of miR-15b in sevoflurane-preconditioned brain, postischemic Bcl-2 expression was significantly increased by sevoflurane preconditioning. We identified the 3'-UTR of Bcl-2 as the target for miR-15b. Molecular inhibition of miR-15b was capable of mimicking the neuroprotective effect of sevoflurane preconditioning, suggesting that the suppression of miR-15b due to sevoflurane contributes to its ischemic neuroprotection. Thus, sevoflurane preconditioning may exert its anti-apoptotic effects by reducing the elevated expression of miR-15b following ischemic injury, allowing its target proteins, including Bcl-2, to be translated and expressed at the protein level.

Expression of apoptosis-associated microRNAs in ethanol-induced acute gastric mucosal injury via JNK pathway

MicroRNAs (miRNAs) have been shown to be closely associated with cellular apoptosis, but their involvement in response to ethanol-induced gastric mucosal epithelial cell apoptosis remains largely unknown. The purpose of this study was to investigate the expression profile of apoptosis-associated miRNAs in ethanol-induced acute gastric mucosal injury and the mechanisms underlying injury. Gastric mucosal injury was induced in rats by oral administration of ethanol, and gastric tissues were collected for analysis of gastric ulcer index, apoptosis ratio, caspase-3 activity, and miRNAs expression. Cell cultures of human gastric mucosal epithelial cells (GES-1) were incubated with ethanol to induce apoptosis. Mimics or inhibitors of miRNAs or c-Jun N-terminal kinase (JNK) inhibitor were added to the cell culture medium. GES-1 cells were collected for analysis of apoptosis ratio, caspase-3 activity, miRNAs expression, and protein phosphorylation levels of JNK, p38 mitogen-activated protein kinase (p38MAPK), or extracellular signal-regulated kinase (ERK). In the animal experiments, gastric ulcer index, cellular apoptosis, and caspase-3 activity were significantly increased, accompanied by up-regulation of miR-145 and down-regulation of the microRNAs miR-17, miR-19a, miR-21, miR-181a, and miR-200c. In the human cell culture experiments, the anti-apoptotic effects of miR-19a and miR-21 or pro-apoptotic effect of miR-145 were confirmed by their corresponding mimics or inhibitor; the ethanol-induced GES-1 apoptosis as well as the changes in miRNAs expression were significantly attenuated in the presence of JNK inhibitor. These results demonstrated that miR-145, miR-19a, and miR-21 were the apoptosis-associated miRNAs in gastric mucosal epithelial cells. The regulation of expression of these 3 miRNAs in ethanol-induced GES-1 apoptosis involved the JNK pathway.

GNAI1 Suppresses Tumor Cell Migration and Invasion and is Post-Transcriptionally Regulated by Mir-320a/c/d in Hepatocellular Carcinoma

Objective

To explore the role and regulation of guanine nucleotide-binding protein G(i), α-1 subunit (GNAI1) in hepatocellular carcinoma (HCC).

Methods

Expression of GNAI1 in HCC samples was determined by qRT–PCR and immunohistochemical (IHC) staining. Huh-7 and SNU-387 cells stably expressing GNAI1 were established by the infection of lentivirus transducing unit containing GNAI1. siRNA against GNAI1 was transfected into SMMC-7721 cells to knock down the GNAI1 expression in HCC cells. Mir-320a/c/d mimics were transfected into SMMC-7721 and SK-Hep-1 cells and the expression of GNAI1 was determined by Western blot. The migration and invasion of Huh-7, SNU-387, SK-Hep-1 and SMMC-7721 cells were investigated by Transwell assays.

Results

The GNAI1 protein was significantly downregulated in HCC samples without changes in its mRNA levels. GNAI1 could inhibit the migration and invasion of HCC cells in vitro. Further investigations indicated that GNAI1 was a target of miR-320a/c/d in HCC cells. Transwell assays demonstrated that these microRNAs could promote the migratory ability and invasivesess of HCC cells in vitro.

Conclusions

GNAI1 is downregulated in HCC and inhibits the migration and invasion of HCC cells. This study is the first to investigate the role of GNAI1 in cancer. Regulation of GNAI1 by miR-320a/c/d indicates new therapeutic avenues for targeting HCC metastasis.

MicroRNA let-7c inhibits Bcl-xl expression and regulates ox-LDL-induced endothelial apoptosis

Endothelial cells (ECs) apoptosis induced by oxidized low-density lipoprotein (ox-LDL) is thought to play a critical role in atherosclerosis. MicroRNAs (miRNAs) are a class of noncoding RNAs that posttranscriptionally regulate the expression of genes involved in diverse cell functions, including differentiation, growth, proliferation, and apoptosis. MiRNA let-7 family is known to be involved in the regulation of cell apoptosis. However, the function of let-7 in ox-LDL induced ECs apoptosis and atherosclerosis is still unknown. Here, we show that let-7c expression was markedly up-regulated in ox-LDL induced apoptotic human umbilical cord vein endothelial cells (HUVECs). Let-7c over-expression enhanced apoptosis in ECs whereas inhibition of let-7c could partly alleviate apoptotic cell death mediated by ox-LDL. Searching for how let-7c affected apoptosis, we discovered that antiapoptotic protein Bcl-xl was a direct target of let-7c in ECs. Our data suggest that let-7c contributes to endothelial apoptosis through suppression of Bcl-xl.

miR-1228 prevents cellular apoptosis through targeting of MOAP1 protein

Apoptosis is a critical cellular process that balances the effects of cell proliferation and cell death. MicroRNAs play important roles in cell growth, differentiation, and apoptosis. In this study, we observed a reduction of miR-1228 expression in apoptotic cells. Enforced miR-1228 expression can reduce MOAP1 expression and delay the progression of stress-induced cell apoptosis. Rescue experiment demonstrated that miR-1228 inhibition of cellular apoptosis is significantly attenuated by repressing MOAP1 expression, suggesting the direct interaction between miR-1228 and MOAP1 protein. Taken together, this study provides evidences that miR-1228 plays an inhibitory role in stress-induced cellular apoptosis. miR-1228 may become a critical therapeutic target for apoptosis relevant diseases in the future.

MicroRNAs: emerging roles in lipid and lipoprotein metabolism

PURPOSE OF REVIEW

MicroRNAs (miRNAs) regulate gene expression by binding to target mRNAs and control a wide range of biological functions. Recent reports have identified specific miRNAs as major regulators of fatty acid and cholesterol homeostasis. This review examines the biological function of various miRNAs and the emerging evidence linking specific miRNAs to critical pathways in lipid metabolism.

RECENT FINDINGS

Disruption of lipid balance can lead to metabolic disturbances and thus tight regulation is required to maintain lipid homeostasis. Recent studies have shown key roles for miR-33 and miR-122 in regulation of lipid metabolism, and further evidence implicates miR-370 in regulation of miR-122. In addition, miRNAs involved in adipogenesis (miR-378/378* and miR-27) as well as newly discovered miRNAs such as miR-613, miR-302a, and miR-168 have now been implicated in regulation of lipid metabolism.

SUMMARY

Growing evidence support key roles for miRNAs in regulating both cholesterol and fatty acid metabolism, leading to considerable interest in miRNAs as potential drug targets to modulate lipid and lipoprotein metabolism. MiRNA-based therapeutics hold considerable promise in the fight to curtail the growing epidemic of obesity and type 2 diabetes and the associated risk of atherosclerosis.

MicroRNA-125b induces metastasis by targeting STARD13 in MCF-7 and MDA-MB-231 breast cancer cells

MicroRNAs (miRNAs) are a class of small noncoding RNAs that regulate gene expression by targeting mRNAs to trigger either translation repression or mRNA degradation. miR-125b is down-regulated in human breast cancer cells compared with the normal ones except highly metastatic tumor cells MDA-MB-231. However, few functional studies were designed to investigate metastatic potential of miR-125b. In this study, the effects of miR-125b on metastasis in human breast cancer cells were studied, and the targets of miR-125b were also explored. Transwell migration assay, cell wound healing assay, adhesion assay and nude mice model of metastasis were utilized to investigate the effects of miR-125b on metastasis potential in vitro and in vivo. In addition, it was implied STARD13 (DLC2) was a direct target of miR-125b by Target-Scan analysis, luciferase reporter assay and western blot. Furthermore, activation of STARD13 was identified responsible for metastasis induced by miR-125b through a siRNA targeting STARD13. qRT-PCR, immunofluorescent assay and western blot was used to observe the variation of Vimentin and α-SMA in breast cancer cells. In summary, our study provided new insights into the function of miR-125b during the metastasis of breat cancer cells and also suggested the role of miR-125b in pro-metastasis by targeting STARD13.

Extracts of Lycoris aurea induce apoptosis in murine sarcoma S180 cells

Lycoris species have been known since long ago as a multi-utility ethnomedicinal herbal in China. It has been reported to exhibit a number of properties such as anticancer, neuroprotective, and antibacterial activities. In the present study, the anticancer efficacy of dichloromethane extracts of Lycoris aurea (DELA), was evaluated both in vivo and in vitro using murine sarcoma 180 cells. To evaluate the effects of DELA on apoptotic cell death, flow cytometry and Western blotting were performed. DELA demonstrated promising inhibition effects on sarcoma 180 cells in vitro and a 53.49% inhibitory rate on cancer cells in vivo. DELA treatment increased thymus indices and spleen indices in vivo, indicating that it reduced tumours, but did not damage the main immune organs. The DELA-evoked increase in apoptotic cell death was accompanied by occurrence of cleaved caspase-3 and decreases in the ratio of Bcl-2/Bax. Further purification and LCMS analysis showed DELA contained homolycorine, 2α-hydroxyoduline, oduline, hippeastrine, 2α-hydroxy-6-O- methyloduline, and 2α-methoxy-6-O-methyloduline. These results indicate that DELA exerted its anticancer effects, at least in part, by inducing cancer cell apoptosis and thus can be considered as a potential candidate agent for treatment of cancer.

Atrial remodeling in atrial fibrillation and some related microRNAs

Atrial fibrillation is the most common sustained arrhythmia associated with substantial cardiovascular morbidity and mortality, with stroke being the most critical complication. The role of atrial remodeling has emerged as the new pathophysiological mechanism of atrial fibrillation. Electrical remodeling and structural remodeling will increase the probability of generating multiple atrial wavelets by enabling rapid atrial activation and dispersion of refractoriness. MicroRNAs (miRNAs) are small non-coding RNAs of 20-25 nucleotides in length that regulate expression of target genes through sequence-specific hybridization to the 3' untranslated region of messenger RNAs and either block translation or direct degradation of their target messenger RNA. They have also been implicated in a variety of pathological conditions, such as arrhythmogenesis and atrial fibrillation. Target genes of miRNAs have the potential to affect atrial fibrillation vulnerability.

Alteration in miRNA gene expression pattern in acute promyelocytic leukemia cell induced by arsenic trioxide: a possible mechanism to explain arsenic multi-target action

MicroRNAs (miRNAs) are involved in cancer pathogenesis, apoptosis, and cell growth, and these miRNAs are thought to be functional as oncogenes and/or tumor suppressors in the gene regulatory networks. We studied the potential contribution of miRNAs in acute promyelocytic leukemia (APL) cell NB4 during the apoptosis induction by arsenic trioxide (ATO). The apoptotic effects of ATO on the NB4 cell line at a pharmacological dose (2 μM) was verified using cell growth and viability assays, MTT assay, BrdU cell proliferation assay, flow cytometric analysis, and caspase-3 activity assay. miRNAs from untreated and 2 μM ATO-treated NB4 cell line were extracted, purified, and converted to complementary DNAs. Differential expressions of 88 cancer-related miRNAs were analyzed by real-time reverse transcription PCR using miRNA PCR cancer-array system. After normalizing to the average Ct value of three housekeeping genes in the array (U6, SNORD47, and SNORD48), the fold change of miRNAs was calculated in the ATO-treated cells as compared to untreated. Among the 88 cancer-focused miRNAs, 51 miRNAs were found to be differentially expressed more than 2-fold after ATO treatment. Of these, 48 miRNAs were upregulated up to 21.65-fold changes, while three miRNAs were downregulated up to 5.19-fold changes. By screening the literature, a majority of these upregulated miRNAs were found to have tumor and/or metastatic suppressors' functions associated with cell cycle arrest and apoptosis, as well as inhibition of angiogenesis, invasion, and metastasis. Our results demonstrate that ATO, at the relevant concentration, modulate a substantial number of cancer-related miRNAs in APL cell line; most of these are known to function as a tumor and/or metastatic suppressors and have confirmed targets involved in cell cycle arrest and apoptosis. The results of this study support the hypothesis that miRNAs may play a mediatory role in eliciting the multi-target and pleiotropic action of ATO.

MiR-204 regulates cardiomyocyte autophagy induced by ischemia-reperfusion through LC3-II

BACKGROUND

Autophagy plays a significant role in myocardial ischemia-reperfusion (IR) injury. So it is important to inhibit autophagy to protect cardiomyocytes besides anti-apoptosis. MiRNA has been demonstrated to protect cardiomyocytes against apoptosis during IR, while whether it has anti-autophagy effect has not been known. The aim of this study was to investigate whether miR-204 regulated autophagy by regulating LC3-II protein, which is the marker of autophagosome during myocardial IR injury.

METHODS

Adult SD rats were randomized to Control and IR groups. IR group was treated with 30 min ischemia by ligating the left anterior descending coronary artery, followed by 2 h reperfusion by loosing the ligation. The expression of miR-204 was measured by RT-PCR, and LC3 protein was measured by western-blot.

RESULTS

We found that IR induced cardiomyocytes autophagy, together with down-regulation of miR-204 and up-regulation of LC3-II protein. And, we have found that LC3-II protein was regulated by miR-204, using the method of transferring miR-204 mimic or AMO-204 into the cardiomyocytes, before.

CONCLUSIONS

These studies provided evidence that miR-204 played an important role in regulating autophagy through LC3-IIprotein during IR.

Identification of microRNA-target interaction in APRIL-knockdown colorectal cancer cells

MicroRNAs (miRNAs) regulate mammalian gene expression by targeting mRNAs and have key roles in several cellular processes, including differentiation, development, apoptosis and cancer pathomechanisms. Our previous studies have confirmed that a proliferation-inducing ligand (APRIL) gene is overexpressed in colorectal cancer (CRC) tumors and SW480 cells. To study the potential mechanisms of APRIL gene in the occurrence and development of the CRC, herein, we investigated whether APRIL-knockdown had the inhibitory effect on the growth of SW480 cells and had the simultaneous expression changes of miRNAs and mRNAs by microarrays. Our results suggest that siRNA-APRIL can effectively inhibit the growth of SW480 cells in vitro and in vivo and several miRNAs via specific pathways might be involved in regulating the phenotype of loss-of-function in APRIL-knockdown SW480 cells. Thus, our study highlights the possible mechanisms of miRNA-target regulating the function of APRIL gene in CRC cells, moreover, siRNA-APRIL holds great promise as a novel gene therapy approach for APRIL- positive CRC treatment.

Essential role of microRNA-155 in the pathogenesis of autoimmune arthritis in mice

OBJECTIVE

MicroRNAs (miRNA) are a new class of regulatory elements. Altered expression of miRNA has been demonstrated in the inflamed joints of patients with rheumatoid arthritis (RA). The aim of this study was to examine the role of miRNA in the pathogenesis of autoimmune arthritis, using 2 murine models.

METHODS

Collagen-induced arthritis (CIA) and K/BxN serum-transfer arthritis were induced in wild-type (WT) and miR-155-deficient (miR-155(-/-) ) mice. The severity of arthritis was determined clinically and histologically. Anticollagen antibodies and cytokines were measured by enzyme-linked immunosorbent assay. The cellular composition of the draining lymph nodes after induction of CIA was measured by flow cytometry.

RESULTS

The miR-155(-/-) mice did not develop CIA. Deficiency in miR-155 prevented the generation of pathogenic autoreactive B and T cells, since anticollagen antibodies and the expression levels of antigen-specific T cells were strongly reduced in miR-155(-/-) mice. Moreover, Th17 polarization of miR-155(-/-) mouse T cells was impaired, as shown by a significant decrease in the levels of interleukin-17 (IL-17) and IL-22. In the K/BxN serum-transfer arthritis model, which only depends on innate effector mechanisms, miR-155(-/-) mice showed significantly reduced local bone destruction, attributed to reduced generation of osteoclasts, although the severity of joint inflammation was similar to that in WT mice.

CONCLUSION

These results demonstrate that miR-155 is essentially involved in the adaptive and innate immune reactions leading to autoimmune arthritis, and therefore miR-155 might provide a novel target for the treatment of patients with RA.

MicroRNAs in idiopathic pulmonary fibrosis

In this review, we describe the recent advances in the understanding of the role of microRNAs in idiopathic pulmonary fibrosis (IPF), a chronic progressive and lethal fibrotic lung disease. Approximately 10% of the microRNAs are significantly changed in IPF lungs. Among the significantly downregulated microRNAs are members of let-7, mir-29, and mir-30 families as well as miR-17∼92 cluster among the upregulated mir-155 and mir-21. Downregulation of let-7 family members leads to changes consistent with epithelial mesenchymal transition in lung epithelial cells both in vitro and in vivo, whereas inhibition of mir-21 modulates fibrosis in the bleomycin model of lung fibrosis. Perturbations of mir-155 and mir-29 have profibrotic effects in vitro but have not yet been assessed in vivo in the context of lung fibrosis. A recurrent global theme is that many microRNAs studied in IPF are both regulated by transforming growth factor β1 (TGFβ1) and regulate TGFβ1 signaling pathway by their target genes. As a result, their aberrant expression leads to a release of inhibitions on the TGFβ1 pathway and to the creation of feed-forward loops. Coanalysis of published microRNA and gene expression microarray data in IPF reveals enrichment of the TGFβ1, Wnt, sonic hedgehog, p53, and vascular endothelial growth factor pathways and complex regulatory networks. The changes in microRNA expression in the IPF lung and the evidence for their role in the fibrosis suggest that microRNAs should be evaluated as therapeutic targets in IPF.

Critical care "normality": individualized versus protocolized care

Patients with critical illness are heterogeneous, with differing physiologic requirements over time. Goal-directed therapy in the emergency room demonstrates that protocolized care could result in improved outcomes. Subsequent studies have confirmed benefit with such a "bundle-based approach" in the emergency room and in preoperative and postoperative scenarios. However, this cannot be necessarily extrapolated to the medium-term and long-term care pathway of the critically ill patient. It is likely that the development of mitochondrial dysfunction could result in goal-directed types of approaches being detrimental. Equally, arterial pressure aims are likely to be considerably different as the patient's physiology moves toward "hibernation." The agents we utilize as sedative and pressor agents have considerable effects on immune function and the inflammatory profile, and should be considered as part of the total clinical picture. The role of gut failure in driving inflammation is considerable, and the drive to feed enterally, regardless of aspirate volume, may be detrimental in those with degrees of ileus, which is often a difficult diagnosis in the critically ill. The pathogenesis of liver dysfunction may be, at least in part, related to venous engorgement that will contribute toward portal hypertension and gut edema. This, in association with loss of the hepatosplanchnic buffer response, it is likely to contribute to venous pooling in the abdominal cavity, impaired venous return, and decreased central blood volumes. Therapies such as those used in "small-for-size syndrome" may have a role in the chronic stages of septic vascular failure.

Epigenetic regulation of cell life and death decisions and deregulation in cancer

For every cell, there is a time to live and a time to die. It is apparent that cell life and death decisions are taken by individual cells based on their interpretation of physiological or non-physiological stimuli, or their own self-assessment of internal damage or changes in their environment. Apoptosis or programmed cell death is a key regulator of physiological growth control and regulation of tissue homoeostasis. One of the most important advances in cancer research in recent years is the recognition that cell death, mostly by apoptosis, is crucially involved in the regulation of tumour formation and also critically determines treatment response. The initiation and progression of cancer, traditionally seen as a genetic disease, is now realized to involve epigenetic abnormalities along with genetic alterations. The study of epigenetic mechanisms in cancer, such as DNA methylation, histone modifications and microRNA expression, has revealed a plethora of events that contribute to the neoplastic phenotype through stable changes in the expression of genes critical to cell death pathways. A better understanding of the epigenetic molecular events that regulate apoptosis, together with the reversible nature of epigenetic aberrations, should contribute to the emergence of the promising field of epigenetic therapy.

MicroRNAs and atrial fibrillation: new fundamentals

Atrial fibrillation (AF) is the most commonly encountered clinical arrhythmia associated with pronounced morbidity, mortality, and socio-economic burden. This pathological entity is associated with an altered expression profile of genes that are important for atrial function. MicroRNAs (miRNAs), a new class of non-coding mRNAs of around 22 nucleotides in length, have rapidly emerged as one of the key players in the gene expression regulatory network. The potential roles of miRNAs in controlling AF have recently been investigated. The studies have provided some promising results for our better understanding of the molecular mechanisms of AF. In this review article, we provide a synopsis of the studies linking miRNAs to cardiac excitability and other processes pertinent to AF. To introduce the main topic, we discuss basic knowledge about miRNA biology and our current understanding of mechanisms for AF. The most up-to-date research data on the possible roles of miRNAs in AF initiation and maintenance are presented, and the available experimental results on miRNA and AF are discussed. Some speculations pertinent to the subject are made. Finally, perspectives on future directions of research on miRNAs in AF are provided.