miRNA-133a Expression Research Articles

Human umbilical cord-derived mesenchymal stromal cells improve myocardial fibrosis and restore miRNA-133a expression in diabetic cardiomyopathy

BackgroundDiabetic cardiomyopathy (DCM) is a serious health-threatening complication of diabetes mellitus characterized by myocardial fibrosis and abnormal cardiac function. Human umbilical cord mesenchymal stromal cells (hUC-MSCs) are a potential therapeutic tool for DCM and myocardial fibrosis via mechanisms such as the regulation of microRNA (miRNA) expression and inflammation. It remains unclear, however, whether hUC-MSC therapy has beneficial effects on cardiac function following different durations of diabetes and which mechanistic aspects of DCM are modulated by hUC-MSC administration at different stages of its development. This study aimed to investigate the therapeutic effects of intravenous administration of hUC-MSCs on DCM following different durations of hyperglycemia in an experimental male model of diabetes and to determine the effects on expression of candidate miRNAs, target mRNA and inflammatory mediators.MethodsA male mouse model of diabetes was induced by multiple low-dose streptozotocin injections. The effects on severity of DCM of intravenous injections of hUC-MSCs and saline two weeks previously were compared at 10 and 18 weeks after diabetes induction. At both time-points, biochemical assays, echocardiography, histopathology, polymerase chain reaction (PCR), immunohistochemistry and enzyme-linked immunosorbent assays (ELISA) were used to analyze blood glucose, body weight, cardiac structure and function, degree of myocardial fibrosis and expression of fibrosis-related mRNA, miRNA and inflammatory mediators.ResultsSaline-treated diabetic male mice had impaired cardiac function and increased cardiac fibrosis after 10 and 18 weeks of diabetes. At both time-points, cardiac dysfunction and fibrosis were improved in hUC-MSC-treated mice. Pro-fibrotic indicators (α-SMA, collagen I, collagen III, Smad3, Smad4) were reduced and anti-fibrotic mediators (FGF-1, miRNA-133a) were increased in hearts of diabetic animals receiving hUC-MSCs compared to saline. Increased blood levels of pro-inflammatory cytokines (IL-6, TNF, IL-1β) and increased cardiac expression of IL-6 were also observed in saline-treated mice and were reduced by hUC-MSCs at both time-points, but to a lesser degree at 18 weeks.ConclusionIntravenous injection of hUC-MSCs ameliorated key functional and structural features of DCM in male mice with diabetes of shorter and longer duration. Mechanistically, these effects were associated with restoration of intra-myocardial expression of miRNA-133a and its target mRNA COL1AI as well as suppression of systemic and localized inflammatory mediators.

Liver Graft MicroRNAs Expression in Different Etiology of Acute Jaundice after Living Donor Liver Transplantation.

Simple SummaryAcute jaundice, a critical problem after living donor liver transplantation, often required efforts to discriminate its etiologies. MicroRNAs are small non-coding RNAs, which express differently during disease development. To differentiate the etiology of acute jaundice after living donor liver transplantation, we examined hepatic microRNA expression patterns in several liver graft pathologies. Eighty liver transplant recipients undergoing post-transplant liver graft biopsy for the evaluation of acute jaundice were enrolled in this one-year prospective study. Using real-time quantitative reverse transcription-polymerase chain reaction profiling assay, we identified intra-graft microRNA (microRNA-122, microRNA-301, microRNA-133a, and microRNA-21) signatures in various allograft pathologies (37 recipients with acute cholangitis, 20 recipients with acute rejection, 12 recipients with recurrent hepatitis, 6 recipients with non-specific pathological change and 5 recipients with fatty change). In acute cholangitis, intra-graft microRNA-122, microRNA-301, and microRNA-21 significantly down-regulated; in acute rejection, intra-graft microRNA-122 significantly up-regulated and intra-graft microRNA-133a significantly down-regulated; in recurrent hepatitis, intra-graft microRNA-122, microRNA-301, and microRNA-21 remarkably up-regulated; and in fatty change, only intra-graft microRNA-133a up-regulated in significance. Our study suggests that specific intra-graft microRNA expression patterns as a checklist may be helpful for differential diagnosis of acute jaundice etiologies following living donor liver transplantation.Background: Acute jaundice remains a critical problem following liver transplantation. MicroRNAs (miRNAs) are involved in regulating gene expression related to various disease phenotypes and statuses. Aims: To differentiate acute jaundice etiology after living donor liver transplantation (LDLT), we examined the hepatic miRNA expression patterns in several liver graft pathologies. Methods: Eighty liver transplant recipients undergoing post-LDLT graft biopsy for the evaluation of acute jaundice were enrolled in this 1-year prospective study. Using a real-time quantitative reverse transcription-polymerase chain reaction profiling assay, we identified hepatic miRNA (miRNA-122, miRNA-301, miRNA-133a, and miRNA-21) signatures in various allografts pathologies. Results: Pathologic findings of the 80 recipients were as follows: acute cholangitis (AC), 37 (46%); acute rejection (AR), 20 (25%); recurrent hepatitis (RH), 12 (15%); non-specific pathological change, 6 (8%); and fatty change (FC), 5 (6%). None of these identified hepatic miRNAs expression pattern was significantly correlated with serum parameters, including neutrophil-lymphocyte ratio. In AC, hepatic miRNA-122, miRNA-301, miRNA-133a, and miRNA-21 expression was significantly downregulated (p < 0.05). MicroRNA-122 expression was elevated in cases of AR and RH (p < 0.05); miRNA-301 and miRNA-21 expression was higher in RH than in AC (p < 0.05); and miRNA-133a expression was higher in FC than in AR (p < 0.05). Conclusions: Our study suggests that specific hepatic miRNA expression patterns as a checklist may be useful for differential diagnosis of acute jaundice following liver transplantation.

Lonicera caerulea Berry Polyphenols Extract Alleviates Exercise Fatigue in Mice by Reducing Oxidative Stress, Inflammation, Skeletal Muscle Cell Apoptosis, and by Increasing Cell Proliferation.

Exercise fatigue can exert deleterious effects on the body. This study evaluated the effects and mechanisms by which Lonicera caerulea berry polyphenols extract (LCBP) improved the treadmill endurance of mice. Comparison was performed between the effects at 25°C and low temperatures (-5°C). Energy storage, product metabolism, and other biochemical indices were determined using vitamin C (VC) as a positive control. Co-immunoprecipitation was performed to detect the interaction between different proteins. Dietary supplementation with LCBP significantly prolonged the exhaustion time during treadmill exercise by 20.4% (25 °C) and 27.4% (-5 °C). LCBP significantly regulated the expression of antioxidant and inflammatory proteins, Bcl-2 /Bax apoptosis proteins, and the PKCα -NOx2 / Nox4 pathway proteins, and activated the expression of AMPK-PGC1α -NRF1-TFAM proteins in skeletal muscle mitochondria. The gene and protein expression of miRNA-133a/IGF-1/PI3K/Akt/mTOR in skeletal muscle cells was also activated. Molecular docking confirmed that the main components of LCBP such as cyanidin-3-glucoside, catechin, and chlorogenic acid, have strong binding affinity toward AMPKα. LCBP alleviates exercise fatigue in mice by reducing oxidative stress, inflammation, and apoptosis of skeletal muscle cells, enhances mitochondrial biosynthesis and cell proliferation, reduces fatigue, and enhances performance. These effects are also significant in a low-temperature environment (Graphical ). Consequently, these results provide novel insights into the anti- fatigue roles of LCBP in exercise fatigue.

The Expression and Role of microRNA-133a in Plasma of Patients with Kawasaki Disease

ABSTRACT Kawasaki disease (KD)), also known as mucocutaneous lymph node syndrome (MCLS), is an autoimmune and systemic vasculitis syndrome. Its etiology and pathogenesis are still unclear. microRNAs (miRNA), a novel class of small non-coding RNAs, regulate the expression of multiple protein-encoding genes at the post-transcriptional level. We intend to study the change of miRNA-133a in the plasma of patients with KD, explore the role of miRNA-133a on HUVEC and define the pathogenesis of vascular dysfunction in KD. miRNA-133a expression and the mRNA and protein expression of protein phosphatase 2 catalytic subunit alpha (PPP2CA) were assessed by RT-qPCR and Western blot, respectively. The PPP2CA mRNA 3ʹUTR was predicted to be the potential target of miRNA-133a by using the miRNA databases and verified by the luciferase assay. The plasmids of miRNA-133a mimics and inhibitors were transfected into HUVEC cells. The plasma soluble vascular endothelial cadherin (sVE-cadherin, the excised extracellular part of VE-cadherin) levels were investigated by ELISA. The results suggested that miRNA-133a was increased by 3.8 times in the acute KD group and by 2.7 times in the convalescent KD group compared with the control group (both P = .000). PPP2CA is the target gene of miRNA-133a and its expression was inhibited by miRNA-133a acting on PPP2CA mRNA 3ʹUTR (P = .013). The plasma sVE-cadherin levels in the acute KD groups were increased compared with the control group (P = .024). The ROC curve analysis showed that the expression of miRNA-133a segregate acute KD patients from convalescent KD patients and healthy children. Our results suggest that miRNA-133a might be a new biomarker for KD.

FOXD3-induced miR-133a blocks progression and metastasis of colorectal cancer through regulating UBA2.

Background and Aim: Some studies have verified that miR-133a played an inhibitory role in several cancers. Whereas, the effect of miRNA-133a in colorectal cancer (CRC) has not been fully elucidated. Our study aims to confirm UBA2 as a direct target gene of miRNA-133a and explore the upstream modulatory molecules of miR-133a. In addition, their impacts on the biological characteristics of CRC cells were assessed.Methods: QRT-PCR analyzed miR-133a expression levels in colorectal cells including HCT116, SW48 cells and human normal colorectal cell line NCM460. A serial biological experiment assessed miR-133a effects on cell proliferation, migration, invasion and apoptosis capacities in HCT116 and SW48 cells. MiRNA targeting gene prediction and a dual luciferase assay were employed to confirm miR-133a-targeted UBA2. Transcription factors (TFs) FOXD3 was identified as an upstream regulator of miR-133a via JASPAR. The influence of miR-133a and FOXD3 on UBA2 expression was analyzed by qRT-PCR or western blot.Results: miR-133a was lowly expressed in CRC cells. High miRNA-133a expression suppressed the proliferation, migration, invasion and enhanced apoptosis capacities of CRC cells. MiR-133a targeted the UBA2 mRNA 3ʹUTR area and reduced UBA2 protein expression. We also unveiled that FOXD3 high-expression significantly raised miR-133a expression and diminished UBA2 expression. We also discovered that high miR-133a expression augmented the effects of elevated FOXD3 expression on CRC cell proliferation, migration and invasion, whereas, low miR-133a expression generated the opposite outcomes.Conclusion: FOXD3 induced miRNA-133a directly targeting UBA2 could affect the progression and growth of CRC.

Plasma MicroRNA-133a as a Potential Predictor for Coronary Artery Stenosis Severity

Background: Several scoring systems tried to determine coronary artery stenosis severity to investigate its correlation with laboratory parameters.Aim of the study: To investigate the correlation between the expression levels of circulating miRNA-133a & coronary artery stenosis severity .Patients and Methods: The study was conducted in Medical Biochemistry Department and Cardiology Department - Faculty of Medicine, Zagazig University& Medical Scientific Research Center. It included 72 subjects classified into 2 groups; Group (1): included 18 healthy subjects served as a control. Group (2 included 54 acute coronary syndrome patients. It was subdivided into 3 subgroups each 18 patient: unstable angina , non-ST-segment elevation myocardial infarction and ST-segment elevation myocardial infarction . Plasma miRNA-133a expression level was analyzed by real time PCR. Cardiac Cathetrization was done for showing the severity of stenosis. Results: The present study showed high significant positive correlation between miRNA-133a level and coronary stenosis percentage in unstable angina group (p

MicroRNA-133a downregulated EGFR expression in human non-small cell lung cancer cells via AKT/ERK signaling.

MicroRNAs (miRNAs) may serve important roles in the regulation of human non-small cell lung cancer (NSCLC) cell growth and apoptosis. To the best of our knowledge, the present study was the first to explore the role of miRNA-133a/epidermal growth factor receptor (EGFR) in regulating NSCLC cell growth and apoptosis via the AKT/extracellular signal-regulated kinase (ERK) signaling pathway. It was determined that miRNA-133a expression was lower in NSCLC tissue than in the adjacent mucosae. Additionally, EGFR expression in the NSCLC tissue was higher compared with in the adjacent mucosae. Furthermore, the upregulation of miRNA-133a in NSCLC cells suppressed cell growth and induced apoptosis. Upregulating miRNA-133a also increased caspase-3 protein expression, while suppressing that of EGFR, phosphorylated (p)-AKT and p-ERK in NSCLC cells. Therefore, the results of the current study demonstrated that miRNA-133a downregulates EGFR expression in NSCLC via the AKT/ERK signaling pathway. These findings provide insights into the function of miRNA-133a in NSCLC, as well as into the molecular mechanisms underlying the miRNA-133a-mediated downregulation of the EGFR/AKT/ERK signaling pathway in NSCLC.

Effects of hydrogen sulfide (H2S) on cardiac hypertrophy and miRNA-133a-mediated Ca2+/calcineurin/NFATc4 signal pathway in rats

To investigate the effects of hydrogen sulfide (H2S) on the negatively regulation of cardiomyocyte hypertrophy and the relationship between the effect of H2S with miRNA-133a-mediated Ca2+/calcineurin/NFATc4 signal pathway. Cardiomyocyte hypertrophy was induced by isoproterenol (ISO). The cell surface area was measured by image analysis system (Leica). The expression of brain natriuretic peptide(BNP), β-myosin heavy chain(β-MHC), cystathionase (CSE), miRNA-133a, calcineurin (CaN) were detected by qRT-PCR. The protein expressions of CaN、nuclear factors of activated T cells (NFATc4) were detected by Western blot. The concentration of H2S in the cardiomyocyte was detected by Elisa. The concentration of intracellular calcium was measured by calcium imaging using confocal microscope. The nuclear translocation of NFATc4 was checked by immuno-fluorescence cell staining technique. ①The level of system of CSE/H2S and expression of miRNA-133a were significantly reduced in cardiomyocyte hypertrophy. Pretreatment with NaHS increased the concentration of H2S and the expression of miRNA-133a mRNA in cardiomyocytes, and suppressed cardiomyocyte hypertrophy. ②The concentration of intracellular calcium, the expression of CaN and nulear protein NFATc4 were significantly increased, and the nuclear translocation of NFATc4 were obviously enhanced in cardiomyocyte hypertrophy. NaHS pretreatment markedly inhibited these effects of ISO induced cardiomyocyte hypertrophy. ③Application of antagomir-133a reversed the inhibitory effects of NaHS on cardiomyocyte hypertrophy, and increased the influx of intracellular calcium, and elevated the expression of CaN and nuclear protein NFATc4, and enhanced the nuclear translocation of NFATc4. H2S can negatively regulate cardiomyocyte hypertrophy. The effects might be associated with H2S increasing expression of miRNA-133a and inhibiting inactivation of Ca2+/calcineurin/NFATc4 signal pathway.

Prognostic Value of MicroRNAs in Coronary Artery Diseases: A Meta-Analysis.

PurposeCoronary artery diseases (CADs) are the leading causes of death in the world. Recent studies have reported that differentially expressed microRNAs (miRNAs) are associated with prognosis or major adverse cardiac events (MACEs) in CAD patients. In a previous meta-analysis, the authors made serious mistakes that we aimed to correct through an updated systematic review and meta-analysis of the prognostic value of altered miRNAs in patients with CADs.Materials and MethodsWe performed a systematic search of MEDLINE (from inception to May 2017) and EMBASE (from inception to May 2017) for English-language publications. Studies of CADs with results on miRNAs that reported survival data or MACEs were included. Data were extracted from each publication independently by two reviewers.ResultsAfter reviewing 515 articles, a total eight studies were included in this study. We measured pooled hazard ratios (HRs) and 95% confidence intervals (CIs) of miRNA 133a with a fixed-effect model (pooled HR, 2.35; 95% CI, 1.56–3.55). High expression of miRNA 133a, 208b, 126, 197, 223, and 122-5p were associated with high mortality. Additionally, high levels of miRNA 208b, 499-5p, 134, 328, and 34a were related with MACEs.ConclusionThe present study confirmed that miRNA 133a, which was associated with high mortality in CAD patients, holds prognostic value in CAD. More importantly, this study corrected issues raised against a prior meta-analysis and provides accurate information.

Comparing the effects of fluticasone, anti-IgE and anti-TNF treatments in a chronic asthma model

BackgroundCorticosteroids are used in the treatment of asthma. The aim of this study was to determine the efficacy of anti-IgE and anti-TNF alpha as asthma treatments. MethodsA mouse model of chronic asthma was developed. The fluticasone group was exposed to fluticasone and the anti-IgE and anti-TNF groups were administered anti-IgE or anti-TNF. IL-4, and IgE levels were measured, and histological analysis, pathological analysis and miRNA-126, miRNA-133a analyses were applied. ResultsThe cell concentration in the BAL fluid decreased in all the treatment groups. The rate of perivascular and peribronchial cell infiltration decreased in the lung in the high-dose anti-IgE and anti-TNF groups. Smooth muscle thickness decreased in the lung tissue in the low-dose anti-IgE and anti-TNF groups. Bronchial wall thickness decreased in the lung tissue in the fluticasone+anti-IgE group. The IL-4 level in BAL fluid decreased in the high-dose anti-IgE, fluticasone+anti-IgE and anti-TNF groups. IgE levels increased in the BAL fluid in the high-dose anti-IgE and anti-TNF groups. The lymphocyte level increased in the BAL fluid in the high-dose anti-IgE group. The macrophage level decreased in the BAL fluid in the anti-TNF group. The relative expression of miRNA-126 increased in all groups. The relative expression of miRNA-133a decreased in the placebo and fluticasone groups. The relative expression of miRNA-133a increased in the low-dose anti-IgE, high-dose anti-IgE, fluticasone+anti-IgE and anti-TNF groups. ConclusionsThe results showed that anti-IgE is successful as a treatment. Fluticasone+anti-IgE and anti-TNF were seen to be superior to other therapeutic modalities when used for prophylaxis.

Effect of α-Hederin on IL-2 and IL-17 mRNA and miRNA-133a Levels in Lungs of Ovalbumin-Sensitized Male Rats.

α-hederin, a saponin that is a major constituent of English Ivy (Hedera helix) is effective in the treatment of asthma. In the present study, the effect of α-hederin on lung tissue pathology and the levels of the inflammatory mediators; IL-2 mRNA, IL-17 mRNA, and MicroRNAs (miRNA)-133a was evaluated in a rat ovalbumin (OVA)-sensitized model of asthma. Rats were divided randomly into control (C), OVA-sensitized (S), OVA-sensitized pretreated with the antioxidant, thymoquinone (3 mg/kg, S + TQ) or OVA-sensitized pretreated with α-hederin (0.02 mg/kg, S + AH) groups. Levels of IL-2 and IL-17 mRNA were higher in the OVA-sensitized group than controls while the level of miRNA-133a gene expression was lower. IL-2 mRNA and miRNA-133a gene expression in the S + TQ group was higher than in the control and OVA-sensitized groups while the level of IL-17 mRNA in the S + TQ group was lower than in the OVA-sensitized group. Pretreatment with α-hederin decreased IL-17 mRNA levels and increased miRNA-133a gene expression compared with OVA-sensitized animals. All pathological changes in pretreated groups were lower than the OVA-sensitized group. These results showed a beneficial effect of α-hederin in OVA-sensitized rats, suggesting that α-hederin affects the IL-2 and IL-17 secretion pathways, altering miRNA-133a expression.

Complex interaction between dengue virus replication and expression of miRNA-133a.

BackgroundDengue virus (DENV) is the most common vector-borne viral infection worldwide with approximately 390 million cases and 25,000 reported deaths each year. MicroRNAs (miRNAs) are small non-coding RNA molecules responsible for the regulation of gene expression by repressing mRNA translation or inducing mRNA degradation. Although miRNAs possess antiviral activity against many mammalian-infecting viruses, their involvement in DENV replication is poorly understood.MethodsHere, we explored the relationship between DENV and cellular microRNAs using bioinformatics tools. We overexpressed miRNA-133a in Vero cells to test its role in DENV replication and analyzed its expression using RT-qPCR. Furthermore, the expression of polypyrimidine tract binding protein (PTB), a protein involved in DENV replication, was analyzed by western blot. In addition, we profiled miRNA-133a expression in Vero cells challenged with DENV-2, using Taqman miRNA.ResultsBioinformatic analysis revealed that the 3' untranslated region (3'UTR) of the DENV genome of all four DENV serotypes is targeted by several cellular miRNAs, including miRNA-133a. We found that overexpression of synthetic miRNA-133a suppressed DENV replication. Additionally, we observed that PTB transcription , a miRNA-133a target, is down-regulated during DENV infection. Based in our results we propose that 3'UTR of DENV down-regulates endogenous expression of miRNA-133a in Vero cells during the first hours of infection.ConclusionsmiRNA-133a regulates DENV replication possibly through the modulation of a host factor such as PTB. Further investigations are needed to verify whether miRNA-133a has an anti-DENV effect in vivo.Electronic supplementary materialThe online version of this article (doi:10.1186/s12879-016-1364-y) contains supplementary material, which is available to authorized users.

Establishment of robust controls for the normalization of miRNA expression in neuroendocrine tumors of the ileum and pancreas

There is need to determine tissue-specific robust controls for normalization of microRNA expression to avoid false results and misinterpretation. The aim of this study was to evaluate the expression of different small RNAs in neuroendocrine tumors (NETs) and their suitability as normalizers in miRNA real-time PCR experiments. We investigated the expression of the nine small RNAs miR-93, miR-191, SNORD48, SNORD61, SNORD68, SNORD72, SNORD95, SNORD96a, and RNU6-2 in formalin-fixed, paraffin-embedded tissue samples of 25 ileal NETs by real-time PCR determining the most stable controls for expression normalization using four different algorithms. This analysis was expended to ten pancreatic NETs. Finally, five small RNAs were further tested as normalizers for miRNA-133a expression, which is known to be downregulated in metastases of ileal NETs, in ten matched pairs of ileal NETs and their metastases. Ranking of the expression results revealed the following order of stability from high to low: SNORD61 < SNORD95 < SNORD72 < SNORD96a < SNORD68 < miR-191 < miR-93 < RNU6-2 < SNORD48 for ileal NETs and SNORD95 < miR-93 < SNORD96a < SNORD61 < SNORD68 < SNORD72 < RNU6-2 < miR-191 < SNORD48 for pancreatic NETs. The determination of SNORD61 and SNORD95 for ileal NETs and SNORD95 and miR-93 for pancreatic NETs as good normalizers presents a useful tool for experiments involving the analysis of miRNA expression.

MicroRNA-133a expression in the ventricular remodeling process after myocardial ischemia-reperfusion injury

Objective To observe the dynamic process of ventricular remodeling after myocardial ischemia-reperfusion injury,and to explore the expression of microRNA (miRNA)-133a in the dynamic process of ventricular remodeling.Methods The model of myocardial ischemia-reperfusion injury in rats was constructed.Healthy adult male wistar rats were randomly divided into two groups:(1) Sham group ; (2) I/R group.In postoperative 1,3,7,15,and 30d,cardiac function was analyzed,indicators of ventricular remodeling and miRNA-133a levels were detected.Results In L/R group:with reperfusion time extension,cardiac function was gradually declined.The expression of type I collagen were significantly higher.Apoptosis were significantly increased (P ＜ 0.05).Ischemia area myocardial fibrosis was gradually worsened.miRNA-133a expression levels were markedly lowered (P ＜ 0.05).On the 3 d after reperfusion,apoptosis rate was highest (54.6 ±-7.3) ％,Fibrosis became obvious [I/R VS Sham:(5.60 ± 2.30) ％ vs.(1.64 ± 0.41) ％,P ＜ 0.05],and miRNA-133a was the lowest (0.57 ± 0.22).Conclusion Fibrosis remodeling occurred after myocardial ischemia-reperfusion.An important period of ventricular remodeling was from 3d after reperfusion.The miRNA-133a expression was significantly lowered in the process of ventricular remodeling after myocardial ischemia-reperfusion injury.miRNA-133a may be involved in the regulation of myocardial ischemia and reperfusion ventricular remodeling process. Key words: MicroRNA-133a; Myocardial ischemia and reperfusion; Ventricular remodeling; Cell apoptosis

MicroRNA expression in ileal carcinoid tumors: downregulation of microRNA-133a with tumor progression

MicroRNAs (miRNAs) are involved in cell proliferation, differentiation, and apoptosis and can function as tumor suppressor genes or oncogenes. The role of miRNAs in neuroendocrine tumors such as ileal carcinoids is largely unknown. We examined the differential expression of 95 miRNAs by RT–PCR using the QuantiMir System in eight matching primary and metastatic carcinoid tumors from the ileum. All miRNAs chosen for the QuantiMir System array were based on their potential functions related to cancer biology, cell development, and apoptosis. The expression of miRNAs for the samples was normalized to miRNA-197, and the matching primary and metastatic tumors were compared. There was downregulation of miRNA-133a, -145, -146, -222, and -10b in all samples between the primary and matching metastatic tumors and upregulation of miRNA-183, -488, and -19a+b in six of eight metastatic carcinoids compared to the primary tumors. miRNA-133a was further analyzed by TaqMan real-time RT–PCR and northern hybridization using six additional matching primary and metastatic samples, which supported the PCR array findings. There were significant differences in miRNA-133a expression with downregulation in the metastasis compared to the primary in the eight original cases (P<0.009) and in the six additional cases used for validation (P<0.014). Laser capture microdissection and real-time RT–PCR analysis using normal ileum found miRNA-133a expression in normal enterochromaffin cells. In situ hybridization in normal ileum showed that some of the mucosal endocrine cells expressed miRNA-133a. Both primary and metastatic ileal carcinoid tumors expressed miRNA-133a by in situ hybridization. These results provide information about novel marker miRNAs that may be used as biomarkers and/or therapeutic targets in intestinal carcinoid tumors.

MiR133a regulates cardiomyocyte hypertrophy in diabetes

Diabetic cardiomyopathy, characterized by cardiac hypertrophy and contractile dysfunction, eventually leads to heart failure. We have previously shown that alterations of a number of key molecules are involved in producing cardiomyocyte hypertrophy in diabetes. The aim of the present study was to determine whether microRNAs (miRNA) play a role in mediating altered gene expression and structural/functional deficits in the heart in diabetes. STZ-induced diabetic mice were haemodynamically investigated after 2 months of diabetes to establish the development of cardiomyopathy. The tissues were then examined for gene expression and microRNA analysis. We further investigated neonatal rat cardiomyocytes to identify the mechanisms of glucose-induced hypertrophy and the potential role of miR133a. Diabetic mice showed myocardial contractile dysfunction and augmented mRNA expression of atrial and brain natriuretic peptides (ANP, BNP), MEF2A and MEF2C, SGK1 and IGF1R compared to age- and sex-matched controls. Cardiac tissues from these mice showed alteration of multiple miRNAs by array analysis including miR133a, which was confirmed by RT-PCR. In vitro exposure of cardiomyocytes to high levels of glucose produced hypertrophic changes and reduced expression of miRNA133a. Finally, transfection of miR133a mimics prevented altered gene expression and hypertrophic changes. Data from these studies demonstrate a novel glucose-induced mechanism regulating gene expression and cardiomyocyte hypertrophy in diabetes which is mediated through miR133a.