Modulation Of miRNA Expression Research Articles

High-throughput chemical screening to discover new modulators of microRNA expression in living cells by using graphene-based biosensor

MicroRNAs (miRNAs) are important regulatory RNAs that control gene expression in various biological processes. Therefore, control over the disease-related miRNA expression is important both for basic research and for a new class of therapeutic modality to treat serious diseases such as cancer. Here, we present a high-throughput screening strategy to identify small molecules that modulate miRNA expression in living cells. The screen enables simultaneous monitoring of the phenotypic cellular changes associated with the miRNA expression by measuring quantitative fluorescent signals corresponding to target miRNA level in living cells based on a novel biosensor composed of peptide nucleic acid and nano-sized graphene oxide. In this study, the biosensor based cellular screening of 967 compounds (including FDA-approved drugs, enzyme inhibitors, agonists, and antagonists) in cells identified four different classes of small molecules consisting of (i) 70 compounds that suppress both miRNA-21 (miR-21) expression and cell proliferation, (ii) 65 compounds that enhance miR-21 expression and reduce cell proliferation, (iii) 2 compounds that suppress miR-21 expression and increase cell proliferation, and (iv) 21 compounds that enhance both miR-21 expression and cell proliferation. We further investigated the hit compounds to correlate cell morphology changes and cell migration ability with decreased expression of miR-21.

Downregulation of miR-130a, antagonized doxorubicin-induced cardiotoxicity via increasing the PPAR\u03b3 expression in mESCs-derived cardiac cells

Doxorubicin (Dox) is a widely used powerful chemotherapeutic component for cancer treatment. However, its clinical application has been hampered due to doxorubicin-induced cardiomyopathy upon the cessation of chemotherapy. Previous studies revealed that PPARγ plays a crucial protective role in cardiomyocytes. Modulation of miRNA expression is an applicable approach for prohibition of toxicity induction. Therefore, the aim of present study is uprising of PPARγ transcript levels via manipulation of miRNAs to limit Dox-induced cardiotoxicity in mESCs-derived cardiac cells, as in vitro model cell to provide a simple direct approach for further clinical therapies. Based on bioinformatics data mining, eventually miR-130a was selected to target PPARγ. This miRNA is highly expressed in heart. The expression of miR-130a increases sharply upon Dox treatment while specific antagomiR-130a reverses Dox-induced reduced expression of PPARγ, cellular apoptosis, and inflammation. Our data strongly suggest that antagomiR-130a limits Dox-induced cellular toxicity via PPARγ upregulation and may have clinical relevance to limit in vivo Dox toxicity.

MiR-532-5p alleviates hypoxia-induced cardiomyocyte apoptosis by targeting PDCD4

MicroRNAs (miRNAs) are a class of endogenous non-coding RNAs involved in regulating various biological processes at the post-transcription level. Accumulating evidence suggests that hypoxia caused by acute myocardial infarction induces cardiomyocyte damage including apoptosis. Previous studies regarding the miRNAome in H9c2 cells under hypoxia have shown that hypoxia modulates miRNA expression in H9c2 cells, including miR-532-5p. We therefore investigated whether miR-532-5p has a potential function in the cardiomyocyte response to hypoxia. In the present study, we found that miR-532-5p, which was down-regulated in hypoxia-exposed H9c2 cells and the myocardium of acute myocardial infarction rats, alleviated hypoxia-induced H9c2 cell apoptosis. Additionally, we identified PDCD4 as the direct target of miR-532-5p, which partly elucidates the anti-apoptotic mechanism of miR-532-5p. In summary, this study revealed that miR-532-5p has cardioprotective effects against hypoxia-induced apoptosis in H9c2 cells.

2,3,7,8 tetrachlorodibenzo-p-dioxin (TCDD)-induced myeloid derived suppressor cells (MDSC) have heightened metabolic activity which correlates with microRNA and gene expression involved in immunosuppression

Abstract Myeloid-derived suppressor cells (MDSCs) are bone marrow (BM)-derived cells consisting of monocytic (M-MDSC) or granulocytic (G-MDSC) subtypes with immunosuppressive activity. In the current study, we examined the metabolism and functions of MDSCs induced by TCDD a highly toxic environmental pollutant. Inasmuch, we injected mice with either vehicle or 10μg/kg TCDD interpersonally and found that TCDD increased both M-MDSCs and G-MDSCs in the peritoneal exudate when compared to controls. We determined the cell bioenergetics in TCDD-induced MDSCs when compared to naïve BM-MDSCs. For this purpose, we examined the mitochondrial oxygen consumption rate (OCR) and found that TCDD-induced MDSCs had heightened basal respiration, ATP-linked respiration, proton (H+) leak, maximal respiration, spare respiratory capacity as well as total proton efflux rate (PER) which means more suppressive function when compared to BM-MDSCs. We next examined whether the heightened metabolic potential in TCDD-induced MDSCs correlated with the microRNA and gene expression. MiRNA array analysis demonstrated that in TCDD-induced MDSCs, certain miRNAs (e.g. mir-543-3p, mir-150-5p) were downregulated which target immunosuppressive genes involved in MDSC functions, such as ARG2, IL-10, STAT-3, and PIM1. Next, we investigated the role of miRNA-150-5p in IL-10, PIM1, and STAT3 expression as well as miRNA-543-3p effects on ARG2 using transfection experiments. We found that MDSCs transfected with mature miRNA-150-5p and miRNA-543-3p were downregulated whereas inhibitors upregulated the expression of respective targets. In summary, our data revealed that TCDD modulates miRNA expression which can impact gene expression and metabolism in MDSC.

Microparticles miRNAs as biomarkers of aerobic exercise efficacy on vascular function and inflammation in obese patients?

The mechanisms involved by physical exercise, controlling inflammation and micro/macro-circulation are not fully identified. However, they are based in part on the regulation of gene expression at the level of blood circulating cells. A new regulatory mechanism of gene expression involves microRNAs (miRNAs), which are transported in the circulation with microparticules (MPs). The modulation of miRNAs expression has recently been implicated in the regulation of inflammation and vascular diseases and thought to be potential biomarkers of exercise response in healthy subject or athletes. However, never such approach on the role of miRNAs as biomarkers of the efficacy of aerobic exercise intervention in obese patients has been realized. Two groups of sedentary ( n = 6, BMI < 25 kg/m 2 ) and obese women ( n = 9, IMC > 30 kg/m 2 ) recruited at F. Hached Hospital (Sousse, Tunisia) were enrolled in an 8-weeks training program. Vascular function was assessed by Laser Doppler Flowmetry, MPs quantification by flow cytometry, miRNAs content by real-time PCR and inflammation by ELISA before and after exercise training. Aerobic exercise improved significantly the endothelial-dependent vasorelaxation in healthy patients and to a lesser extent in obese patients, improved systemic inflammation, and increased circulating MPs level in both groups. The miRNA profile analysis revealed that (1) miR-21,-150,-320a,-146a,-124a,-126 and -223 were expressed in circulating MPs of sedentary healthy and obese women; (2) after aerobic exercise, the expression of miR-21,-146a,-124a,-150,-320a was differentially overexpressed in healthy and obese subjects while miR-126 and -223 remained unchanged; and finally (3) significant correlation was found between miR-150 and -320a and adiponectin and TNF-α levels. Our results highlight the incidence of aerobic exercise training on MPs content and their role as vehicle for miRNAs, which function as intercellular communication devices regulating particularly inflammation.

Modulation of miRNA expression in aged rat hippocampus by buttermilk and krill oil

The increasing incidence of age-induced cognitive decline justifies the search for complementary ways of prevention or delay. We studied the effects of concentrates of phospholipids, sphingolipids, and/or 3-n fatty acids on the expression of genes or miRNAs related to synaptic activity and/or neurodegeneration, in the hippocampus of aged Wistar rats following a 3-month supplementation. The combination of two phospholipidic concentrates of krill oil (KOC) and buttermilk (BMFC) origin modulated the hippocampal expression of 119 miRNAs (11 were common to both BMFC and BMFC + KOC groups). miR-191a-5p and miR-29a-3p changed significantly only in the BMFC group, whereas miR-195-3p and miR-148a-5p did so only in the combined-supplemented group. Thirty-eight, 58, and 72 differentially expressed genes (DEG) were found in the groups supplemented with KOC, BMFC and BMFC + KOC, respectively. Interaction analysis unveiled networks of selected miRNAs with their potential target genes. DEG found in the KOC and BMFC groups were mainly involved in neuroactive processes, whereas they were associated with lysosomes and mRNA surveillance pathways in the BMFC + KOC group. We also report a significant reduction in hippocampal ceramide levels with BMFC + KOC. Our results encourage additional in-depth investigations regarding the potential beneficial effects of these compounds.

Honokiol suppresses proliferation and induces apoptosis via regulation of the miR‑21/PTEN/PI3K/AKT signaling pathway in human osteosarcoma cells.

Honokiol (HNK) is a small biphenolic compound, which exerts antineoplastic effects in various types of cancer. However, the mechanism underlying the antitumor effects of HNK in osteosarcoma (OS) cells is not yet fully understood. Emerging evidence has indicated that microRNAs (miRNAs/miRs) serve key roles in numerous pathological processes, including cancer. It has previously been reported that Chinese medicinal herbs harbor anticancer properties via modulating miRNA expression. Therefore, the present study aimed to determine whether HNK could suppress OS cell growth by regulating miRNA expression. The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and flow cytometric analysis were used to evaluate the cell proliferation and apoptosis in human OS cells after treatment with HNK, respectively. The results demonstrated that HNK inhibits proliferation and induces apoptosis of human OS cells in a dose-dependent manner. Furthermore, HNK-induced apoptosis was characterized by upregulation of proapoptotic proteins, including cleaved-caspase-3, cleaved-poly (ADP-ribose) polymerase and B-cell lymphoma 2 (Bcl-2)-associated X protein, and downregulation of the anti-apoptotic protein Bcl-2. Reverse transcription-quantitative polymerase chain reaction (RT-qPCR) verified that HNK was able to induce aberrant expression of miRNAs in human OS cells, and miR-21 was one of the miRNAs that was most significantly downregulated. To further investigate miR-21 function, the present study validated that HNK reduces miR-21 levels in a dose-dependent manner. In addition, restoration of miR-21 expression abrogated the suppressive effects of HNK on OS cells. Luciferase assay and western blot analysis identified that miR-21 inhibits the expression of phosphatase and tensin homolog (PTEN) by directly targeting its 3′-UTR. Notably, HNK was able to suppress the phosphoinositide 3-kinase (PI3K)/protein kinase B (AKT) signaling pathway; however, it was reactivated by miR-21 overexpression. Taken together, these data indicated that HNK may inhibit proliferation and induce apoptosis of human OS cells by modulating the miR-21/PTEN/PI3K/AKT signaling pathway. Therefore, miR-21 may be considered a potential therapeutic target for the treatment of osteosarcoma with HNK.

Role of dietary phytochemicals in modulation of miRNA expression: Natural swords combating breast cancer

The National Cancer Institute had projected breast cancer (BC) as one of the topmost prevalent malignancies around the globe. In many cases, BC becomes resistant to chemotherapy, radiation and hormonal therapies. Traditional BC therapies are associated with adverse side effects, drug resistance and recurrence. Extensive research work has shown that these dietary phytochemicals (DPs) may exert therapeutic effects by regulating the miRNA expression. A large number of DPs have been researched as miRNA regulatory agents against BC and some other DPs have not yet been tested against BC. We have discussed the effects of curcumin, diallyl disulphide, 3,3′ diindolylmethane, ellagic acid, genistein, indole-3-carbinol, quercetin, resveratrol, and sulforaphane on regulation of expression of BC miRNAs in a wide range of in vitro and in vivo models. We have also shown some of the possible DPs (Oleanolic acid, capsaicin, benzyl isothiocyanate, epigallocatechin gallate, phenethyl isothiocyanate and ursolic acid) that have shown miRNA regulatory activities and have not yet been tested against BC miRNAs. Finally, current limitations, challenges, future perspectives of DPs and BC research are also critically discussed.

The involvement of serum exosomal miR-500-3p and miR-770-3p in aging: modulation by calorie restriction.

Recent studies have shown a role for miRNAs in aging and age-related diseases, and the modulation of miRNA expression by diet attracts attention as a new therapeutic strategy. Here, we focused on identifying specific exosomal miRNAs derived from serum of aged rats and the effect of short-term calorie restriction (CR) on their expression.Exosomes from serum of young (7-month), old (22-month), and old-CR Sprague Dawley rats were isolated and characterized by transmission electron microscopy analyses, dynamic light scattering measurements, and Western blotting. A total of 12 significantly expressed miRNAs in serum exosomes of young and old rats were identified by next generation sequencing. After analysis of qRT-PCR, we found that miR-500-3p and miR-770-3p expression was significantly upregulated by aging and downregulated by CR. Furthermore, receiver operating characteristic (ROC) curve revealed that the selected miRNAs represented high accuracy in discriminating old rats from young rats. Finally, PANTHER analysis predicted selected miRNAs targets genes involved in Wnt/chemokines and cytokines -related inflammatory signaling pathway and function as transcription factor.In conclusion, our results suggest that the expression of serum exosomal miR-500-3p and miR-770-3p was significantly increased with aging, whereas these were decreased by CR, and age-/CR-modulated exosomal miR-500-3p and miR-770-3p could potentially be used as informative biomarkers candidates for aging.

BET bromodomain inhibitor JQ1 modulates microRNA expression in thyroid cancer cells.

Anaplastic thyroid carcinoma (ATC) represents the most lethal thyroid cancer sub-type, currently unresponsive to standard treatments. Recently, bromodomain and extra-terminal (BET) proteins have emerged as attractive therapeutic targets in several diseases, including cancer. In different cancer models, the anti-neoplastic activity of BET inhibitors such as JQ1, I-BET762 and I-BET151 have already been established, due to both direct and indirect effects. miRNAs are 20-22nucleotide transcriptional regulators which play important roles in proliferation, differentiation and apoptosis. Hitherto, the relationship between JQ1 and miRNAs has not been explored. The goal of this study was to delineate JQ1-associated miRNA regulation in ATC cells. Two ATC-derived cell lines (SW1736 and 8505c) were treated with either 5µM JQ1 or vehicle for 48or 72h. A non-tumorigenic thyroid cell line (Nthy-ori3-1) was used as a control. miRNome analysis displayed a JQ1-related dysregulation of several miRNAs, 7of which turned out to be commonly dysregulated in both cell lines at both time-points. Furthermore, miR-4516 turned out to be downregulated in both ATC cell lines, when compared to the non-tumorigenic ones and notably, JQ1 treatment in both ATC cell lines induced its upregulation, restoring, in some way, its basal expression levels. We, therefore, focused on miR-4516 expression and STAT3 levels, since it was previously predicted to be a putative target of this microRNA. Consistently, phospho-STAT3 and its target p21Waf1/Cip1 turned out to be downregulated and upregulated in both JQ1-treated ATC cell lines, respectively. Thus, our data revealed that modulation of miRNA expression is one of the multiple mechanisms of the effect of JQ1 in thyroid cancer cells.

Chemoprevention by resveratrol and pterostilbene: Targeting on epigenetic regulation.

Epigenetic mechanisms are essential in regulating normal cellular functions and play an important role during the disease developmental stages. However, aberrant epigenetic mechanisms may lead to pathological consequences such as cancer, neurological disorders, bone and skeletal diseases, cardiovascular dysfunction, and metabolic syndrome. The molecular mechanisms of epigenetic modification include DNA methylation, histone modification (acetylation, methylation and phosphorylation), and microRNAs (miRNAs). Unlike genetic modifications, epigenetic states of genes are reversible and can be altered by certain intrinsic and extrinsic factors. In the past few decades, accumulated evidence shows that dietary phytochemicals with chemopreventive effects are also potent epigenetic regulators. Resveratrol and pterostilbene are stilbenoids, which have been reported to have anti-cancer, anti-inflammatory, anti-lipid, and anti-diabetic properties. Stilbenoids are also reported to improve cardiovascular disease. By altering DNA methylation and histone modification or by modulating miRNA expression, resveratrol, and pterostilbene become potent epigenetic modifiers. In this review, we summarize these studies and underlying mechanisms of resveratrol and pterostilbene and their influence on epigenetic mechanisms. © 2017 BioFactors, 44(1):26-35, 2018.

Intrahepatic MicroRNA Profile of Liver Transplant Recipients with Hepatitis C Virus Co-Infected with Human Immunodeficiency Virus

BackgroundIn patients with human immunodeficiency virus (HIV) and hepatitis C virus (HCV) co-infection, HIV can modulate HCV replication and immune response as well as accelerate liver fibrosis. The role of miRNA in HIV/HCV co-infection is not fully elucidated. The aim of this study was to examine the differential expression of miRNAs in the liver.Material/MethodsThirteen patients who had undergone a liver transplant (7 HCV-infected and 6 HIV/HCV-co-infected patients) were examined using a miRNA array containing 1347 human miRNAs. To confirm the microarray results, data for 20 patients (10 HCV-infected and 10 HIV/HCV-co-infected) were validated using real-time polymerase chain reaction probing for miR101b, miR149, and miR200c. This miRNA was selected based on microarray results and its biological significance in liver fibrosis.ResultsMicroarray analysis revealed 22 miRNAs that were differentially expressed in the HIV/HCV-co-infected group compared to the HCV-infected group (p<0.05). The expression of miR-101b and miR149 was significantly decreased in the HIV/HCV-co-infected group compared to that in the HCV-infected group (miR101b, 0.103±0.09 vs. 0.0157±0.0093, p=0.007; miR149, 0.152±0.159 vs. 0.0192±0.015, p=0.025).ConclusionsHIV/HCV co-infection may promote liver fibrosis by modulating miRNA expression.

Haloperidol induces pharmacoepigenetic response by modulating miRNA expression, global DNA methylation and expression profiles of methylation maintenance genes and genes involved in neurotransmission in neuronal cells.

IntroductionHaloperidol has been extensively used in various psychiatric conditions. It has also been reported to induce severe side effects. We aimed to evaluate whether haloperidol can influence host methylome, and if so what are the possible mechanisms for it in neuronal cells. Impact on host methylome and miRNAs can have wide spread alterations in gene expression, which might possibly help in understanding how haloperidol may impact treatment response or induce side effects.MethodsSK-N-SH, a neuroblasoma cell line was treated with haloperidol at 10μm concentration for 24 hours and global DNA methylation was evaluated. Methylation at global level is maintained by methylation maintenance machinery and certain miRNAs. Therefore, the expression of methylation maintenance genes and their putative miRNA expression profiles were assessed. These global methylation alterations could result in gene expression changes. Therefore genes expressions for neurotransmitter receptors, regulators, ion channels and transporters were determined. Subsequently, we were also keen to identify a strong candidate miRNA based on biological and in-silico approach which can reflect on the pharmacoepigenetic trait of haloperidol and can also target the altered neuroscience panel of genes used in the study.ResultsHaloperidol induced increase in global DNA methylation which was found to be associated with corresponding increase in expression of various epigenetic modifiers that include DNMT1, DNMT3A, DNMT3B and MBD2. The expression of miR-29b that is known to putatively regulate the global methylation by modulating the expression of epigenetic modifiers was observed to be down regulated by haloperidol. In addition to miR-29b, miR-22 was also found to be downregulated by haloperidol treatment. Both these miRNA are known to putatively target several genes associated with various epigenetic modifiers, pharmacogenes and neurotransmission. Interestingly some of these putative target genes involved in neurotransmission were observed to be upregulated while CHRM2 gene expression was down regulated.ConclusionsHaloperidol can influence methylation traits thereby inducing a pharmacoepigenomic response, which seems to be regulated by DNMTs and their putative miRNA expression. Increased methylation seems to influence CHRM2 gene expression while microRNA could influence neurotransmission, pharmacogene expression and methylation events. Altered expression of various therapeutically relevant genes and miRNA expression, could account for their role in therapeutic response or side effects.

Systemic antimiR-337-3p delivery inhibits cerebral ischemia-mediated injury

Modulation of miRNA expression has been shown to be beneficial in the context of multiple diseases. The purpose of this study was to determine if an inhibitor of miR-337-3p is neuroprotective for hypoxic injury after tail vein injection. We evaluated miR-337-3p expression levels and in brain tissue in vivo before and after permanent middle cerebral artery occlusion (pMCAO) in mice. Subsequently, a custom locked nucleic acid (LNA) antimir-337-3p oligonucleotide was developed and tested in vitro after induction of oxygen glucose-deprivation (OGD) and in vivo by injection into the mouse tail vein for 3 consecutive days before pMCAO. Ischemic lesion volume was measured by TTC staining. We show that systemically administered LNA antimir-337-3p crosses the blood brain-brain-barrier (BBB), penetrates into neurosn, downregulates endogenous miR-337-3p expression and reduces ischemic brain injury. The findings support the use of similar antimir-LNA constructs as novel therapies in neurological disease.

Coordinated Actions of MicroRNAs with other Epigenetic Factors Regulate Skeletal Muscle Development and Adaptation.

Epigenetics plays a pivotal role in regulating gene expression in development, in response to cellular stress or in disease states, in virtually all cell types. MicroRNAs (miRNAs) are short, non-coding RNA molecules that mediate RNA silencing and regulate gene expression. miRNAs were discovered in 1993 and have been extensively studied ever since. They can be expressed in a tissue-specific manner and play a crucial role in tissue development and many biological processes. miRNAs are responsible for changes in the cell epigenome because of their ability to modulate gene expression post-transcriptionally. Recently, numerous studies have shown that miRNAs and other epigenetic factors can regulate each other or cooperate in regulating several biological processes. On the one hand, the expression of some miRNAs is silenced by DNA methylation, and histone modifications have been demonstrated to modulate miRNA expression in many cell types or disease states. On the other hand, miRNAs can directly target epigenetic factors, such as DNA methyltransferases or histone deacetylases, thus regulating chromatin structure. Moreover, several studies have reported coordinated actions between miRNAs and other epigenetic mechanisms to reinforce the regulation of gene expression. This paper reviews multiple interactions between miRNAs and epigenetic factors in skeletal muscle development and in response to stimuli or disease.

New insights into vitamin D anticancer properties: focus on miRNA modulation.

Vitamin D anticancer properties are well known and have been demonstrated in many in vitro and in vivo studies. Mechanistic insights have given an explanation on how vitamin D exerts antineoplastic functions, which are mainly conducted via the canonical vitamin D receptor (VDR)-vitamin D response elements (VDRE) pathway. Numerous findings indicate that dietary components, including vitamin D, could exert chemopreventive effects through alterations of microRNA (miRNA) expression. As miRNAs have important roles in regulating diverse and vital cellular processes, it has been speculated that vitamin D's non-classical effects, including anticancer effects, could be mediated through alterations of miRNA expression level. The current review focuses on up-to-date experimental data on modulation of miRNA expression by vitamin D treatment in cancer, obtained in a cell culture system, animal models and human cohorts. Reported findings in the review show that vitamin D modulates expression of numerous and diverse miRNAs specific for cancer types. Even in its early phases, with many questions remaining to be answered, dissecting the molecular pathways of vitamin D miRNA modulation is an emerging area of science. The complete unraveling of vitamin D molecular mechanisms will emphasize the vitamin D dietary component as a potential chemopreventive agent in cancer and personalized nutrition.

Identification and Characterization of MicroRNA Differentially Expressed in Macrophages Exposed to Porphyromonas gingivalis Infection.

MicroRNAs (miRNAs) are short, noncoding RNAs involved in the regulation of several processes associated with inflammatory diseases and infection. Bacterial infection modulates miRNA expression to subvert any innate immune response. In this study we analyzed, using microarray analysis, the bacterial modulation of miRNAs in bone marrow-derived macrophages (BMMs) in which activity was induced by infection with Porphyromonas gingivalis The expression of several miRNAs was modulated 3 h postinfection (at a multiplicity of infection of 25). A bioinformatic analysis was performed to further identify pathways related to the innate immune host response under the influence of selected miRNAs. To assess the effects of the miRNAs identified on cytokine secretion (tumor necrosis factor alpha [TNF-α] and interleukin-10 [IL-10]), BMMs were transfected with selected miRNA mimics and inhibitors. Transfection with mmu-miR-155 and mmu-miR-2137 did not modify TNF-α secretion, while their inhibitors increased it. Inhibitors of mmu-miR-2137 and mmu-miR-7674 increased the secretion of the anti-inflammatory factor IL-10. In P. gingivalis-infected BMMs, mmu-miR-155-5p significantly decreased TNF-α secretion while inhibitor of mmu-miR-2137 increased IL-10 secretion. In vivo, in a mouse model of P. gingivalis-induced calvarial bone resorption, injection of mmu-miR-155-5p or anti-mmu-miR-2137 reduced the size of the lesion significantly. Furthermore, anti-mmu-miR-2137 significantly reduced inflammatory cell infiltration, osteoclast activity, and bone loss. Bioinformatic analysis demonstrated that pathways related to cytokine- and chemokine-related pathways but also osteoclast differentiation may be involved in the effects observed. This study contributes further to our understanding of P. gingivalis-induced modulation of miRNAs and their physiological effects. It highlights the potential therapeutic merits of targeting mmu-miR-155-5p and mmu-miR-2137 to control inflammation induced by P. gingivalis infection.

Impact of Polyunsaturated Fatty Acids on miRNA Profiles of Monocytes/Macrophages and Endothelial Cells-A Pilot Study.

Alteration of miRNAs and dietary polyunsaturated fatty acids (PUFAs) underlies vascular inflammation. PUFAs are known to be incorporated into the cell membrane of monocytes/macrophages or endothelial cells, the major cellular players of vascular diseases, thereby affecting cellular signal transduction. Nevertheless, there are no investigations concerning the PUFA impact on miRNA expression by these cells. With regard to the key role miRNAs play for overall cellular functionality, this study aims to elucidate whether PUFAs affect miRNA expression profiles. To this end, the monocyte/macrophage cell line RAW264.7 and the endothelial cell line TIME were enriched with either docosahexaenoic acid (DHA; n3-PUFA) or arachidonic acid (AA; n6-PUFA) until reaching a stable incorporation into the plasma membrane and, at least in part, exposed to an inflammatory milieu. Expressed miRNAs were determined by deep sequencing, and compared to unsupplemented/unstimulated controls. Data gained clearly show that PUFAs in fact modulate miRNA expression of both cell types analyzed regardless the presence/absence of an inflammatory stimulator. Moreover, certain miRNAs already linked to vascular inflammation were found to be affected by cellular PUFA enrichment. Hence, vascular inflammation appears to be influenced by dietary fatty acids, inter alia, via PUFA-mediated modulation of the type and amount of miRNAs synthesized by cells involved in the inflammatory process.

Role of phytochemicals in the modulation of miRNA expression in cancer.

MicroRNAs (miRNAs) are single-stranded non-coding endogenous RNAs linked with normal developmental and physiological processes. Recent studies have demonstrated that the dysregulation of miRNAs plays an important role in the beginning, progression, and metastasis of many cancers. Additionally, they are involved in the regulation of the epithelial-to-mesenchymal transition (EMT) in many cancer cells. Several studies have suggested that phytochemicals play an important role in the modulation of miRNA expression, which is related to changes in oncogenes, tumour suppressors, and cancer-related protein expression. Hence, phytonutrients can suppress tumour development, prevent metastasis, reverse the EMT, and improve drug sensitivity via the modulation of miRNA expression. In this review, we discuss tumour-suppressing and oncogenic miRNAs and the mechanism of action for miRNAs as well as the role of phytochemicals in the modulation of miRNAs in various cancer cells.

Baicalein, a Natural Anti-Cancer Compound, Alters MicroRNA Expression Profiles in Bel-7402 Human Hepatocellular Carcinoma Cells

Background/Aims: Baicalein has been shown to possess significant anti-hepatoma activity by inhibiting cell proliferation. Whether the anti-proliferative effect of baicalein is related to its modulation of miRNA expression in hepatocellular carcinoma (HCC) is still unknown. Methods: The anti-proliferative effects of baicalein on HCC cell line Bel-7402 was assessed by detecting the proliferation activity, cell cycle distribution, expression changes of p21/CDKN1A, P27/CDKN1B, total Akt and phosphoryted AKT. Microarray analysis was conducted to determine the miRNA expression profiles in baicalein-treated or untreated Bel-7402 cells and then validated by qRT-PCR in two HCC cell lines (Bel-7402 and Hep3B). The gain-of-function of miR-3127-5p was performed by detecting anti-proliferative effects after transfecting miRNA mimics in cells. Finally, the expression level of miR-3127-5p in different HCC cell lines was determined by qRT-PCR. Results: Baicalein was able to inhibit the proliferation of Bel-7402 cells by inducing cell cycle arrest at the S and G2/M phase via up-regulating the expression of p21/CDKN1A and P27/CDKN1B and suppressing the PI3K/Akt pathway. Baicalein could alter the miRNA expression profiles in Bel-7402 cells. Putative target genes for differentially expressed miRNAs could be enriched in terms of cell proliferation regulation, cell cycle arrest and were mainly involved in MAPK, PI3K-Akt, Wnt, Hippo and mTOR signaling pathways. MiR- 3127-5p, one of up-regulated miRNAs, exhibits low expression level in several HCC cell lines and its overexpression could inhibit cell growth of Bel-7402 and Hep3B cell lines by inducing S phase arrest by up-regulating the expression of p21and P27 and repressing the PI3K/Akt pathway. Conclusions: Modulation of miRNA expression may be an important mechanism underlying the anti-hepatoma effects of baicalein.