miR Expression Profiles Research Articles

Deregulation of microRNA expression in monocytes and CD4+ T lymphocytes from patients with axial spondyloarthritis

BackgroundMicroRNAs (MiRs) play an important role in the pathogenesis of chronic inflammatory diseases. This study is the first to investigate miR expression profiles in purified CD4+ T lymphocytes and CD14+ monocytes from patients with axial spondyloarthritis (axSpA) using a high-throughput qPCR approach.MethodsA total of 81 axSpA patients fulfilling the 2009 ASAS classification criteria, and 55 controls were recruited from October 2014 to July 2017. CD14+ monocytes and CD4+ T lymphocytes were isolated from peripheral blood mononuclear cells. MiR expression was investigated by qPCR using the Exiqon Human MiRnome panel I analyzing 372 miRNAs. Differentially expressed miRNAs identified in the discovery cohort were validated in the replication cohort.ResultsWe found a major difference in miR expression patterns between T lymphocytes and monocytes regardless of the patient or control status. Comparing disease-specific differentially expressed miRs, 13 miRs were found consistently deregulated in CD14+ cells in both cohorts with miR-361-3p, miR-223-3p, miR-484, and miR-16-5p being the most differentially expressed. In CD4+ T cells, 11 miRs were differentially expressed between patients and controls with miR-16-1-3p, miR-28-5p, miR-199a-5p, and miR-126-3p were the most strongly upregulated miRs among patients. These miRs are involved in disease relevant pathways such as inflammation, intestinal permeability or bone formation. Mir-146a-5p levels correlated inversely with the degree of inflammation in axSpA patients.ConclusionsWe demonstrate a consistent deregulation of miRs in both monocytes and CD4+ T cells from axSpA patients, which could contribute to the pathophysiology of the disease with potential interest from a therapeutic perspective.

236: Micro RNA expression profile in pregnant women complicated fetuses with muscular ventricular septal defects

Ventricular septal defects (VSD) account for 20% of congenital heart defects (CHDs) and the pathogenesis and molecular mechanism have not been elucidated. MicroRNAs (miRs) are small single-stranded, non-coding RNA molecules that regulate gene expression at the post-transcriptional level. Recent research demonstrated that miRs help regulate embryonic cardiac development, cardiac mophogenesis, and cardiomyocyte growth and differentiation and are closely related to the occurrence of CHDs. This study aimed to measure differences in miR expression in maternal serum in patients complicated with fetal muscular VSD. This was a prospective study including fetuses at risk for CHD (pregestational diabetes, anticonvulsant use, or history of cardiac defects) during 2nd trimester echocardiographic examination. Fetuses without cardiac abnormalities were marked as control. Fetuses with isolated mVSD were marked as abnormal. Maternal venous serum was collected, RNA extracted, and an expression profile of 797 human miRs was measured using NanoString nCounter technology as counts (molecules/100ng RNA). Expression levels of >2fold increase or <50% decrease compared to control were considered up- or downregulated, respectively. Placental-derived miRs within the entire expression profile were also evaluated separately. miRs profiling was obtained in 6 controls and 7 mVSDs cases. Expression levels ranged from 3-198 counts, indicating relatively low expression. The median count did not vary between normal (20.7) and mVSD (21.4). Of the 797, 12 miRs were significantly upregulated (Fig. 1) and 36 miRs downregulated (P<0.01 for both). There were no differences in expression among the 114 known placentally-derived miRs between groups. This study identifies a select serum miR expression profile in women with mVSD fetuses in the 2nd trimester that differs from women with normal fetuses. This approach may provide a quantitative screening tool for confirming fetal CHDs diagnosed by echocardiography. This will be valuable as a biomarker approach for early detection of fetal CHDs in the first trimester to aid diagnosis by fetal echocardiography.

Exosomes derived from preadipocytes improve osteogenic differentiation, potentially via reduced miR‑223 expression.

Insufficient bone volume remains a key issue when using dental implants. Adipose tissue-derived stem cells (ADSCs) can accelerate bone healing when combined with dental implants. To improve the application of ADSCs for dental uses, the present study aimed to identify optimal implantation conditions. Mesenchymal stem cell-derived exosomes can induce naïve stem cells to differentiate through the osteogenic lineage. In the present study, exosomes derived from 3T3L1 preadipocytes (3T3L1-exo) were purified and characterized. The effects and potential mechanisms of 3T3L1-exo on 3T3L1 cell ossification were examined by reverse transcription-quantitative polymerase chain reaction, western blotting, electron microscopy, RNA sequencing and histological analysis. The current study confirmed that 3T3L1-exo enhanced 3T3L1 preadipocyte osteogenic differentiation, as revealed by upregulation of osteogenic differentiation-associated genes and increased Alizarin Red staining. Furthermore, the microRNA (miR) expression profiles of 3T3L1-exo and 3T3L1 preadipocytes were sequenced and compared. The results of a further analysis demonstrated that miR-223 expression was reduced in 3T3L1 preadipocytes stimulated by 3T3L1-exo compared with in unstimulated cells. This finding suggested that 3T3L1-exo promoted 3T3L1 bone formation by decreasing miR-223 through a competitive mechanism, another miRNA, or another factor. The mechanism by which miR-223 is decreased warrants further investigation. In conclusion, the application of 3T3L1-exo may be useful for investigating preadipocyte-induced bone regeneration.

Combination of a six microRNA expression profile with four clinicopathological factors for response prediction of systemic treatment in patients with advanced colorectal cancer.

BackgroundFirst line chemotherapy is effective in 75 to 80% of patients with metastatic colorectal cancer (mCRC). We studied whether microRNA (miR) expression profiles can predict treatment outcome for first line fluoropyrimidine containing systemic therapy in patients with mCRC.MethodsMiR expression levels were determined by next generation sequencing from snap frozen tumor samples of 88 patients with mCRC. Predictive miRs were selected with penalized logistic regression and posterior forward selection. The prediction co-efficients of the miRs were re-estimated and validated by real-time quantitative PCR in an independent cohort of 81 patients with mCRC.ResultsExpression levels of miR-17-5p, miR-20a-5p, miR-30a-5p, miR-92a-3p, miR-92b-3p and miR-98-5p in combination with age, tumor differentiation, adjuvant therapy and type of systemic treatment, were predictive for clinical benefit in the training cohort with an AUC of 0.78. In the validation cohort the addition of the six miR signature to the four clinicopathological factors demonstrated a significant increased AUC for predicting treatment response versus those with stable disease (SD) from 0.79 to 0.90. The increase for predicting treatment response versus progressive disease (PD) and for patients with SD versus those with PD was not significant. in the validation cohort. MiR-17-5p, miR-20a-5p and miR-92a-3p were significantly upregulated in patients with treatment response in both the training and validation cohorts.ConclusionA six miR expression signature was identified that predicted treatment response to fluoropyrimidine containing first line systemic treatment in patients with mCRC when combined with four clinicopathological factors. Independent validation demonstrated added predictive value of this miR-signature for predicting treatment response versus SD. However, added predicted value for separating patients with PD could not be validated. The clinical relevance of the identified miRs for predicting treatment response has to be further explored.

Alterations of MicroRNA Expression in the Liver, Heart, and Testis of Mice Upon Exposure to Repeated Low-Dose Radiation.

MicroRNAs (miRs), which regulate target gene expression at the post-transcriptional level, play a crucial role in inducing biological effects upon high-dose ionizing radiation. Yet, the miR expression profiles in response to repeated low-dose radiation (LDR) in vivo have not been elucidated. This study investigated the response profiles of 11 miRs with functions involved in metabolism, DNA damage and repair, inflammation, and fibrosis in mouse liver, heart, and testis upon repeated LDR exposure for 4 months. The expression profiles were evaluated using stem-loop quantitative reverse transcription polymerase chain reaction immediately and at 2 months after LDR exposure. The expression profiles varied significantly at both time points. At the organ level, the heart was the most affected, followed by the liver and testis, in which significant miR upregulation related to DNA damage response was found. Metabolism-related miRs decreased in the liver and increased in the testis. The current results showed immediate and long-lasting alterations in the miR expression profiles in response to repeated LDR in different organs.

The Changes of MicroRNA Expression in the Corpus Cavernosum of a Rat Model With Cavernous Nerve Injury

BackgroundMicroRNAs (miRs) were found to be dysregulated in erectile dysfunction (ED) related to aging, type 2 diabetes mellitus, and vasculogenic abnormalities. However, miR expression in ED after radical prostatectomy (RP) is not known. AimTo detect abnormal miR expression in post-RP ED and analyze target genes and pathways. Methods16 Sprague Dawley rats were divided into bilateral cavernous nerve crush (BCNC) and control groups. 4 weeks after surgery, erectile function and histological change in the corpus cavernosum were evaluated. Total RNA from 3 rats from each group was isolated and processed to analyze the miR expression profiling by RNA sequencing. The top 10 up-regulated miR profiles were chosen directly and further validated in another 5 rats per each group by quantitative real-time polymerase chain (PCR) reaction. The target genes were predicted by online databases, including: TargetScan, mirwalk, miRanda, miRDB, and DIANA. The enrichment analysis of gene ontology-term analysis and Kyoto Encyclopedia of Genes and Genomes were performed by DAVID database. OutcomesIntra-cavernosal pressure, mean arterial pressure, smooth muscle content, and miR expression were measured. ResultsCompared to the control group, the BCNC group had decreased intra-cavernosal/mean arterial pressure ratio and smooth muscle marker (α-smooth muscle actin). The sequence results showed that 124 miR expression dysregulated in the BCNC group, in which 122 miR expression were up-regulated. Of the 122 miRs, 21 miR expressions were increased above 2-fold. Among the top 10 up-regulated miRs, 4 miRs (miR-101a, miR-138, miR-338, and miR-142) levels were finally validated for over-expression by quantitative (PCR) reaction. The gene ontology analysis results showed that these 4 miRs could regulate the processes of cell apoptosis, fibrosis, endothelium, and smooth muscle cells function. The Kyoto Encyclopedia of Genes and Genomes pathway analysis showed the target genes were involved in 7 pathways related to ED. Clinical TranslationOur findings provide novel insights into post-RP ED that may stimulate further studies to develop miR targeted therapy or damage detection for ED. Strengths & LimitationsTo our knowledge, this is the first study to identify the miR profiling and function in the BCNC rat model. The rat model might not represent the human condition and the miR was only detected at 1 period. Besides that, there is a high probability of false positives for RNA sequence results. Conclusion4 dysregulated miRs were found in the BCNC rat model, which may be related to post-RP ED by regulating apoptosis, fibrosis, endothelial, and smooth muscle cells.Liu C, Cao Y, Ko TC, et al. The Changes of MicroRNA Expression in the Corpus Cavernosum of a Rat Model With Cavernous Nerve Injury. J Sex Med 2018;15:958–965.

MicroRNA expression profile of human advanced coronary atherosclerotic plaques

MicroRNA (miR) is reported to be involved in vascular inflammation and may represent a novel class of diagnostic biomarkers in cardiovascular disease. We aimed to identify the miR expression profile in human advanced coronary atherosclerotic plaques (CAP) and to connect this expression to the processes in atherosclerosis. Microarray techniques and TaqMan polymerase chain reaction were used to analyse the global expression of 352 miRs in CAP obtained during ACS MULTI-LINK study. 11 miRs were selected on the basis of their implication in atherosclerosis, endothelial activation, and inflammation. 6 miRs were found to be differently expressed in CAP when compared to non-atherosclerotic internal mammary arteries (IMA, p < 0.05). The expression of miR-21, -92a, and -99a was verified and found to be significantly up-regulated in CAP versus IMA (p < 0.001). We also performed bioinformatic analysis and found several potential target genes of miR-92a and -99a as well as several pathways with impact on atherosclerosis which could be differently expressed due to this miRNA profile. The most up-regulated miRs are involved in processes known to be connected to atherosclerosis. Interfering with the miR expression in the artery wall is a potential way to affect atherosclerotic plaque and cardiovascular disease development.

MicroRNA-451a regulates colorectal cancer proliferation in response to radiation

BackgroundColorectal cancer (CRC) is a leading cause of cancer-related death. The biologic response of CRC to standard of care adjuvant therapies such as chemotherapy and radiation are poorly understood. MicroRNAs (miRs) have been shown to affect CRC progression and metastasis. Therefore, we hypothesized that specific miRs modulate CRC response to chemoradiation.MethodsIn this study, we used miR expression profiling and discovered a set of microRNAs upregulated rapidly in response to either a single 2 Gy dose fraction or a 10 Gy dose of γ-radiation in mouse colorectal carcinoma models. We used gain and loss-of-function studies in 2D and 3Dcell proliferation assays and colony formation assays to understand the role of the top miR candidate from our profiling. We used Student’s T-tests for simple comparisons and two-factor ANOVA for evaluating significance.ResultsThe most upregulated candidate at early time points in our signature, miR-451a inhibited tumor cell proliferation and attenuated surviving fraction in longer-term cultures. Conversely, inhibition of miR-451a increased proliferation, tumorsphere formation, and surviving fraction of tumor cells. Using a bioinformatics approach, we identified four genes, CAB39, EMSY, MEX3C, and EREG, as targets of miR-451a. Transfection of miR-451a decreased both mRNA and protein levels of these targets. Importantly, we found miR-451a expression was high and CAB39, EMSY levels were low in a small subset of rectal cancer patients who had a partial response to chemoradiation when compared to patients that had no response. Finally, analysis of a TCGA colorectal cancer dataset revealed that CAB39 and EMSY are upregulated at the protein level in a significant number of CRC patients. Higher levels of CAB39 and EMSY correlated with poorer overall survival.ConclusionsTaken together, our data indicates miR-451a is induced by radiation and may influence colorectal carcinoma proliferation via CAB39 and EMSY pathways.

MicroRNA-145-5p and microRNA-320a encapsulated in endothelial microparticles contribute to the progression of vasculitis in acute Kawasaki Disease

Kawasaki Disease (KD) is an acute inflammatory disease that takes the form of systemic vasculitis. Endothelial microparticles (EMPs) have been recognized as an important transcellular delivery system. We hypothesized whether EMPs are involved in vasculitis in acute KD. Fifty patients with acute KD were enrolled, divided into two subgroups: those with coronary artery lesions (CAL) (n = 5) and those without CAL (NCAL) (n = 45). EMPs were measured using flow cytometry, and microRNA (miR) expression profiling was performed by microRNA array. The percentage of EMPs in acute KD was significantly higher than in controls (P < 0.0001). EMPs in patients with CAL rapidly increased after the initial treatment, and was significantly higher than those in NCAL (P < 0.001). In patients with CAL, we identified 2 specific miRs encapsulated in EMPs, hsa-miR-145-5p and hsa-miR-320a, which are predicted to affect monocyte function using in silico analysis, and were demonstrated to upregulate inflammatory cytokine mRNAs in THP-1 monocytes. In situ hybridization confirmed that hsa-miR-145-5p was preferentially expressed in CAL. EMPs may serve as a sensitive marker for the severity of vasculitis in acute KD. Moreover, these 2 specific miRs encapsulated in EMPs might be involved in inflammatory cytokine regulation and the pathogenesis of vasculitis in acute KD.

Changes of Circulating MicroRNAs in Response to Treatment With Teriparatide or Denosumab in Postmenopausal Osteoporosis.

Expression of microRNAs (miRs) related to bone metabolism in the serum may be affected by antiosteoporotic treatment. To investigate the effect of two antiosteoporotic agents with opposite effects on bone metabolism on miR expression profile in the serum. Observational, open label, nonrandomized clinical trial. The outpatient clinics for Metabolic Bone Diseases of 424 General Military Hospital, Thessaloniki, Greece. Postmenopausal women with low bone mass were treated with either teriparatide (TPTD; n = 30) or denosumab (n = 30) for 12 months. Changes in the serum expression of selected miRs linked to bone metabolism at 3 and 12 months of treatment. Secondary measurements: associations of measured miRs with changes in bone mineral density (BMD) at 12 months and the bone turnover markers (BTMs) C-terminal cross-linking telopeptide of type I collagen and procollagen type I N-terminal propeptide at 3 and 12 months. We found significantly decreased relative expression of miR-33-3p at 3 months (P = 0.03) and of miR-133a at 12 months (P = 0.042) of TPTD treatment. BMD values at 12 months of TPTD treatment were significantly and inversely correlated with miR-124-3p expression at 3 months (P = 0.008). Relative expression of miR-24-3p and miR-27a was correlated with changes in BTMs during TPTD treatment and of miR-21-5p, miR-23a-3p, miR-26a-5p, miR-27a, miR-222-5p, and miR-335-5p with changes in BTMs during denosumab treatment. Circulating miRs are differentially affected by treatment with TPTD and denosumab. TPTD affects the relative expression of miRs related to the expression of RUNX-2 (miR-33) and DKK-1 gene (miR-133).

Characterization and assessment of potential microRNAs involved in phosphate-induced aortic calcification.

Medial artery calcification, a hallmark of type 2 diabetes mellitus and chronic kidney disease (CKD), is known as an independent risk factor for cardiovascular mortality and morbidity. Hyperphosphatemia associated with CKD is a strong stimulator of vascular calcification but the molecular mechanisms regulating this process remain not fully understood. We showed that calcification was induced after exposing Sprague-Dawley rat aortic explants to high inorganic phosphate level (Pi , 6 mM) as examined by Alizarin red and Von Kossa staining. This calcification was associated with high Tissue-Nonspecific Alkaline Phosphatase (TNAP) activity, vascular smooth muscle cells de-differentiation, manifested by downregulation of smooth muscle 22 alpha (SM22α) protein expression which was assessed by immunoblot analysis, immunofluorescence, and trans-differentiation into osteo-chondrocyte-like cells revealed by upregulation of Runt related transcription factor 2 (Runx2), TNAP, osteocalcin, and osteopontin mRNA levels which were determined by quantitative real-time PCR. To unravel the possible mechanism(s) involved in this process, microRNA (miR) expression profile, which was assessed using TLDA technique and thereafter confirmed by individual qRT-PCR, revealed differential expression 10 miRs, five at day 3 and 5 at day 6 post Pi treatment versus control untreated aortas. At day 3, miR-200c, -155, 322 were upregulated and miR-708 and 331 were downregulated. After 6 days of treatment, miR-328, -546, -301a were upregulated while miR-409 and miR-542 were downregulated. Our results indicate that high Pi levels trigger aortic calcification and modulation of certain miRs. These observations suggest that mechanisms regulating aortic calcification might involve miRs, which warrant further investigations in future studies.

Whole blood microRNA expression pattern differentiates patients with rheumatoid arthritis, their seropositive first-degree relatives, and healthy unrelated control subjects

BackgroundEpigenetic mechanisms can integrate gene-environment interactions that mediate disease transition from preclinical to clinically overt rheumatoid arthritis (RA). To better understand their role, we evaluated microRNA (miRNA, miR) expression profile in indigenous North American patients with RA who were positive for anticitrullinated protein antibodies; their autoantibody-positive, asymptomatic first-degree relatives (FDRs); and disease-free healthy control subjects (HCs).MethodsTotal RNA was isolated from whole blood samples obtained from HC (n = 12), patients with RA (n = 18), and FDRs (n = 12). Expression of 35 selected relevant miRNAs, as well as associated downstream messenger RNA (mRNA) targets of miR-103a-3p, was determined by qRT-PCR.ResultsWhole blood expression profiling identified significantly differential miRNA expression in patients with RA (13 miRNAs) and FDRs (10 miRNAs) compared with HCs. Among these, expression of miR-103a-3p, miR-155, miR-146a-5p, and miR-26b-3p was significantly upregulated, whereas miR-346 was significantly downregulated, in both study groups. Expression of miR-103a-3p was consistently elevated in FDRs at two time points 1 year apart. We also confirmed increased miR-103a-3p expression in peripheral blood mononuclear cells from patients with RA compared with HCs. Predicted target analyses of differentially expressed miRNAs in patients with RA and FDRs showed overlapping biological networks. Consistent with these curated networks, mRNA expression of DICER1, AGO1, CREB1, DAPK1, and TP53 was downregulated significantly with miR-103a-3p expression in FDRs.ConclusionsWe highlight systematically altered circulating miRNA expression in at-risk FDRs prior to RA onset, a profile they shared with patients with RA. Prominently consistent miR-103a-3p expression indicates its utility as a prognostic biomarker for preclinical RA while highlighting biological pathways important for transition to clinically detectable disease.

MicroRNAs in the development and neoplasia of the mammary gland

Study on the role of microRNAs (miRs) as regulators of gene expression through posttranscriptional gene silencing is currently gaining much interest,due to their wide involvement in different physiological processes. Understanding mammary gland development, lactation, and neoplasia in relation to miRs is essential. miR expression profiling of the mammary gland from different species in various developmental stages shows their role as critical regulators of development. miRs such as miR-126, miR-150, and miR-145 have been shown to be involved in lipid metabolism during lactation. In addition, lactogenic hormones influence miR expression as evidenced by overexpression of miR-148a in cow mammary epithelial cells, leading to enhanced lactation. Similarly, the miR-29 family modulates lactation-related gene expression by regulating DNA methylation of their promoters. Besides their role in development, lactation and involution, miRs are responsible for breast cancer development. Perturbed estrogen (E2) signaling is one of the major causes of breast cancer. Increased E2 levels cause altered expression of ERα, and ERα-miR cross-talk promotes tumour progression. miRs, such as miR-206, miR-34a, miR-17-5p, and miR-125 a/b are found to be tumour suppressors; whereas miR-21, miR-10B, and miR-155 are oncogenes. Oncogenic miRs like miR-21, miR-221, and miR-210 are overexpressed in triple negative breast cancer cases which can be diagnostic biomarker for this subtype of cancer. This review focuses on the recent findings concerning the role of miRs in developmental stages of the mammary gland (mainly lactation and involution stages) and their involvement in breast cancer progression. Further studies in this area will help us to understand the molecular details of mammary gland biology, as well as miRs that could be therapeutic targets of breast cancer.

Profile of MicroRNA Expression in Endometrial Cell during In Vitro Culture According to Progesterone Concentration.

Artificial uterus using endometrium implant can be a novel treatment strategy for infertile women with refractory endometrial dysfunction. At early pregnancy, the function of uterine endometrial cells for the communication between the conceptus of pre-implantation period and maternal reproductive system is essential. MicroRNA (miR) expression profile of endometrial cells according to progesterone, a crucial pregnancy-maintaining hormone, provides important data for in vitro endometrial cell culture strategy that is useful for engineering artificial uteri using endometrial implants. The present study aimed to evaluate the miR expression profile of in vitro cultured endometrial cells under hormonal milieu mimicking early pregnancy period in terms of progesterone concentration. We cultured murine uterine endometrial cells, human uterine endometrial carcinoma cells, and immortalized human uterine endometrial cells using different progesterone concentrations, and analyzed the expression of miRs critical for early pregnancy. The expression of miR-20a, -21, -196a, -199a, and -200a was differently regulated according to progesterone concentration in different endometrial cell lines. The analysis of candidate target genes showed that the expression of phosphatase and tensin homolog, mucin 1 (MUC1), progesterone receptor, transforming growth factor β receptor II, matrix metallopeptidase-9 was up-regulated by progesterone treatment in mouse and human endometrial cell lines. These results indicate that physiological concentration range (10-7 and 10-9 M) of progesterone affect the survival and target gene expression via modulating miR expression. Taken together, progesterone can be a crucial factor in regulating miR expression on in vitro cultured endometrial cells.

MicroRNAs in the development and neoplasia of the mammary gland.

Study on the role of microRNAs (miRs) as regulators of gene expression through posttranscriptional gene silencing is currently gaining much interest,due to their wide involvement in different physiological processes. Understanding mammary gland development, lactation, and neoplasia in relation to miRs is essential. miR expression profiling of the mammary gland from different species in various developmental stages shows their role as critical regulators of development. miRs such as miR-126, miR-150, and miR-145 have been shown to be involved in lipid metabolism during lactation. In addition, lactogenic hormones influence miR expression as evidenced by overexpression of miR-148a in cow mammary epithelial cells, leading to enhanced lactation. Similarly, the miR-29 family modulates lactation-related gene expression by regulating DNA methylation of their promoters. Besides their role in development, lactation and involution, miRs are responsible for breast cancer development. Perturbed estrogen (E2) signaling is one of the major causes of breast cancer. Increased E2 levels cause altered expression of ERα, and ERα-miR cross-talk promotes tumour progression. miRs, such as miR-206, miR-34a, miR-17-5p, and miR-125 a/b are found to be tumour suppressors; whereas miR-21, miR-10B, and miR-155 are oncogenes.Studies using an ACI rat model showed similar findings of miR dysregulation due to excess E2, and a natural phenol antioxidant ellagic acid showed therapeutic properties by reversing the miR dysregulation. This review focuses on the recent findings concerning the role of miRs in developmental stages of the mammary gland (mainly lactation and involution stages) and their involvement in breast cancer progression. Further studies in this area will help us understand the molecular details of mammary gland biology,as well as miRs that could be therapeutic targets of breast cancer.

MicroRNAs in Muscle: Characterizing the Powerlifter Phenotype.

Powerlifters are the epitome of muscular adaptation and are able to generate extreme forces. The molecular mechanisms underpinning the significant capacity for force generation and hypertrophy are not fully elucidated. MicroRNAs (miRs) are short non-coding RNA sequences that control gene expression via promotion of transcript breakdown and/or translational inhibition. Differences in basal miR expression may partially account for phenotypic differences in muscle mass and function between powerlifters and untrained age-matched controls. Muscle biopsies were obtained from m. vastus lateralis of 15 national level powerlifters (25.1 ± 5.8 years) and 13 untrained controls (24.1 ± 2.0 years). The powerlifters were stronger than the controls (isokinetic knee extension at 60°/s: 307.8 ± 51.6 Nm vs. 211.9 ± 41.9 Nm, respectively P < 0.001), and also had larger muscle fibers (type I CSA 9,122 ± 1,238 vs. 4,511 ± 798 μm2 p < 0.001 and type II CSA 11,100 ± 1,656 vs. 5,468 ± 1,477 μm2 p < 0.001). Of the 17 miRs species analyzed, 12 were differently expressed (p < 0.05) between groups with 7 being more abundant in powerlifters and five having lower expression. Established transcriptionally regulated miR downstream gene targets involved in muscle mass regulation, including myostatin and MyoD, were also differentially expressed between groups. Correlation analysis demonstrates the abundance of eight miRs was correlated to phenotype including peak strength, fiber size, satellite cell abundance, and fiber type regardless of grouping. The unique miR expression profiles between groups allow for categorization of individuals as either powerlifter or healthy controls based on a five miR signature (miR-126, -23b, -16, -23a, -15a) with considerable accuracy (100%). Thus, this unique miR expression may be important to the characterization of the powerlifter phenotype.

Pterostilbene suppresses human endometrial cancer cells in vitro by down-regulating miR-663b.

Resveratrol has long been known as an antioxidant and a chemopreventive agent. Similar to resveratrol, pterostilbene (PT) is also a phenolic compound extracted from the Vitis species. However, there are few studies on the antitumor effect of PT. Thus, we investigated the effects of PT on the endometrial cancer (EC) cells in vitro and the related molecular mechanisms. Treatment of EC cell lines HTB-111 and Ishikawa with PT (25-100 μmol/L) dose-dependently suppressed the cell viability and induced apoptosis. Using miR microarrays, we examined the miR expression profile in Ishikawa cells with or without PT, and revealed that miR-663b was the most decreased in PT-treated Ishikawa cells. Furthermore, we predicted and verified that the pro-apoptosis factor BCL2L14 is the direct target of miR-663b. Over-expression of miR-663b and knock-down of BCL2L14 counteracted the suppressing effects of PT on HTB-111 and Ishikawa cells. In addition, we evaluated the miR-663b levels in EC tissues of 51 patients using an in situ hybridization technique. With the median of the score of miR-663b as a cut-off value, these EC patients were divided into two groups, and the patients with high miR-663b expression had significantly poor prognosis.

Dysregulation of miRNA Expression in Cancer Associated Fibroblasts (CAFs) and Its Consequences on the Tumor Microenvironment.

The tumor microenvironment, including cancer-associated fibroblasts (CAF), has developed as an important target for understanding tumor progression, clinical prognosis and treatment responses of cancer. Cancer cells appear to transform normal fibroblasts (NF) into CAFs involving direct cell-cell communication and epigenetic regulations. This review summarizes the current understanding on miR involvement in cancer cell—tumor environment/stroma communication, transformation of NFs into CAFs, their involved targets and signaling pathways in these interactions; and clinical relevance of CAF-related miR expression profiles. There is evidence that miRs have very similar roles in activating hepatic (HSC) and pancreatic stellate cells (PSC) as part of precancerous fibrotic diseases. In summary, deregulated miRs affect various intracellular functional complexes, such as transcriptional factors, extracellular matrix, cytoskeleton, EMT/MET regulation, soluble factors, tyrosine kinase and G-protein signaling, apoptosis and cell cycle & differentiation, but also formation and composition of the extracellular microenvironment. These processes result in the clinical appearance of desmoplasia involving CAFs and fibrosis characterized by deregulated stellate cells. In addition, modulated release of soluble factors can act as (auto)activating feedback loop for transition of NFs into their pathological counterparts. Furthermore, epigenetic communication between CAFs and cancer cells may confer to cancer specific functional readouts and transition of NF. MiR related epigenetic regulation with many similarities should be considered as key factor in development of cancer and fibrosis specific environment.

Attenuation of Staphylococcal enterotoxin-B (SEB)-induced lung injury (ALI) by resveratrol results from miR-193a down-regulation and alterations in metabolic profile

Abstract Resveratrol, (RES), a phytoalexin, is well-known for its anti-inflammatory and anti-oxidant properties. SEB, a superantigen, is known to trigger ALI and cause mortality. In the current study, we tested the effect of RES in a dual-dose model of SEB exposure that triggers ALI and causes 100% mortality in C3H/HeJ-mice. The data revealed RES attenuated SEB-induced ALI and prevented mortality. Forty eight hours post-SEB exposure, lung-infiltrating mononuclear cells were tested for microRNA expression profile to determine the epigenetic regulation by resveratrol. SEB-activated splenocytes were pre-treated with 50 μM of RES or vehicle for metabolic profile analysis by measuring oxygen consumption rate (OCR) and extracellular acidification rate (ECAR). We also noted significant decline in miR-193a in the lungs of RES-treated SEB group, which targeted and caused an increase in TGFβ2 and TGFβR3, potent inhibitors of T-cell proliferation, by using RT-PCR and validation by transfection studies. RES-induced downregulation of miR-193a also influenced the activity of mechanistic target of rapamycin (mTOR) as well as pyruvate kinase muscle isozyme2 (PKM2) genes, and caused RES-treated SEB-activated T cells to be quiescent metabolically in comparison to the energetic vehicle-treated SEB-activated T cells. Together, RES caused inhibition in the proliferation of SEB-activated T-cells by alterations in miR expression and metabolic profiles. (Supported by NIH grants P01AT003961, R01AT006888, R01ES019313, R01MH094755, P20GM103641 and R01AI129788).

Dicer and microRNAs protect adult dopamine neurons

MicroRNAs (miRs) are important post-transcriptional regulators of gene expression implicated in neuronal development, differentiation, aging and neurodegenerative diseases, including Parkinson’s disease (PD). Several miRs have been linked to PD-associated genes, apoptosis and stress response pathways, suggesting that deregulation of miRs may contribute to the development of the neurodegenerative phenotype. Here, we investigate the cell-autonomous role of miR processing RNAse Dicer in the functional maintenance of adult dopamine (DA) neurons. We demonstrate a reduction of Dicer in the ventral midbrain and altered miR expression profiles in laser-microdissected DA neurons of aged mice. Using a mouse line expressing tamoxifen-inducible CreERT2 recombinase under control of the DA transporter promoter, we show that a tissue-specific conditional ablation of Dicer in DA neurons of adult mice led to decreased levels of striatal DA and its metabolites without a reduction in neuronal body numbers in hemizygous mice (DicerHET) and to progressive loss of DA neurons with severe locomotor deficits in nullizygous mice (DicerCKO). Moreover, we show that pharmacological stimulation of miR biosynthesis promoted survival of cultured DA neurons and reduced their vulnerability to thapsigargin-induced endoplasmic reticulum stress. Our data demonstrate that Dicer is crucial for maintenance of adult DA neurons, whereas a stimulation of miR production can promote neuronal survival, which may have direct implications for PD treatment.