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Item Argonaute 2 Expression Correlates with a Luminal B Breast Cancer Subtype and Induces Estrogen Receptor Alpha Isoform Variation(MDPI, 2016-09-21) Conger, Adrienne K.; Martin, Elizabeth C.; Yan, Thomas J.; Rhodes, Lyndsay V.; Hoang, Van T.; La, Jacqueline; Anbalagan, Muralidharan; Burks, Hope E.; Rowan, Brian G.; Nephew, Kenneth P.; Collins-Burow, Bridgette M.; Burow, Matthew E.; Cellular and Integrative Physiology, School of MedicineEstrogen receptor alpha (ERα) signaling pathways are frequently disrupted in breast cancer and contribute to disease progression. ERα signaling is multifaceted and many ERα regulators have been identified including transcription factors and growth factor pathways. More recently, microRNAs (miRNAs) are shown to deregulate ERα activity in breast carcinomas, with alterations in both ERα and miRNA expression correlating to cancer progression. In this study, we show that a high expression of Argonaute 2 (AGO2), a translation regulatory protein and mediator of miRNA function, correlates with the luminal B breast cancer subtype. We further demonstrate that a high expression of AGO2 in ERα+ tumors correlates with a poor clinical outcome. MCF-7 breast cancer cells overexpressing AGO2 (MCF7-AGO2) altered ERα downstream signaling and selective ERα variant expression. Enhanced ERα-36, a 36 kDa ERα isoform, protein and gene expression was observed in vitro. Through quantitative polymerase chain reaction (qPCR), we demonstrate decreased basal expression of the full-length ERα and progesterone receptor genes, in addition to loss of estrogen stimulated gene expression in vitro. Despite the loss, MCF-7-AGO2 cells demonstrated increased estrogen stimulated tumorigenesis in vivo. Together with our clinical findings on AGO2 expression and the luminal B subtype, we suggest that AGO2 is a regulator of altered ERα signaling in breast tumors.Item Biomarkers of β-Cell Stress and Death in Type 1 Diabetes(Springer, 2016-10) Mirmira, Raghavendra G.; Sims, Emily K.; Syed, Farooq; Evans-Molina, Carmella; Medicine, School of MedicineThe hallmark of type 1 diabetes (T1D) is a decline in functional β-cell mass arising as a result of autoimmunity. Immunomodulatory interventions at disease onset have resulted in partial stabilization of β-cell function, but full recovery of insulin secretion has remained elusive. Revised efforts have focused on disease prevention through interventions administered at earlier disease stages. To support this paradigm, there is a parallel effort ongoing to identify circulating biomarkers that have the potential to identify stress and death of the islet β-cells. Whereas no definitive biomarker(s) have been fully validated, several approaches hold promise that T1D can be reliably identified in the pre-symptomatic phase, such that either β-cell preservation or immunomodulatory agents might be employed in at-risk populations. This review summarizes the most promising protein- and nucleic acid-based biomarkers discovered to date and reviews the context in which they have been studied.Item Computational Analysis of Drought Stress-Associated miRNAs and miRNA Co-Regulation Network in Physcomitrella patens.(Elsevier, 2011-04) Wan, Ping; Wu, Jun; Zhou, Yuan; Xiao, Junshu; Feng, Jie; Zhao, Weizhong; Xiang, Shen; Jiang, Guanglong; Chen, Jake Yue; Department of Biohealth Informatics, IU School of Informatics and ComputingmiRNAs are non-coding small RNAs that involve diverse biological processes. Until now, little is known about their roles in plant drought resistance. Physcomitrella patens is highly tolerant to drought; however, it is not clear about the basic biology of the traits that contribute P. patens this important character. In this work, we discovered 16 drought stress-associated miRNA (DsAmR) families in P. patens through computational analysis. Due to the possible discrepancy of expression periods and tissue distributions between potential DsAmRs and their targeting genes, and the existence of false positive results in computational identification, the prediction results should be examined with further experimental validation. We also constructed an miRNA co-regulation network, and identified two network hubs, miR902a-5p and miR414, which may play important roles in regulating drought-resistance traits. We distributed our results through an online database named ppt-miRBase, which can be accessed at http://bioinfor.cnu.edu.cn/ppt_miRBase/index.php. Our methods in finding DsAmR and miRNA co-regulation network showed a new direction for identifying miRNA functions.Item Downregulation of p16 Decreases Biliary Damage and Liver Fibrosis in the Mdr2 / Mouse Model of Primary Sclerosing Cholangitis(Cognizant Communication Corporation, 2020-11) Kyritsi, Konstantina; Francis, Heather; Zhou, Tianhao; Ceci, Ludovica; Wu, Nan; Yang, Zhihong; Meng, Fanyin; Chen, Lixian; Baiocchi, Leonardo; Kundu, Debjyoti; Kennedy, Lindsey; Liangpunsakul, Suthat; Wu, Chaodong; Glaser, Shannon; Alpini, Gianfranco; Medicine, School of MedicineBiliary senescence and hepatic fibrosis are hallmarks of cholangiopathies including primary sclerosing cholangitis (PSC). Senescent cholangiocytes display senescence-associated secretory phenotypes [SASPs, e.g., transforming growth factor-1 (TGF-1)] that further increase biliary senescence (by an autocrine loop) and trigger liver fibrosis by paracrine mechanisms. The aim of this study was to determine the effect of p16 inhibition and role of the TGF-1/microRNA (miR)-34a/sirtuin 1 (SIRT1) axis in biliary damage and liver fibrosis in the Mdr2/ mouse model of PSC. We treated (i) in vivo male wild-type (WT) and Mdr2/ mice with p16 Vivo-Morpholino or controls before measuring biliary mass [intrahepatic bile duct mass (IBDM)] and senescence, biliary SASP levels, and liver fibrosis, and (ii) in vitro intrahepatic murine cholangiocyte lines (IMCLs) with small interfering RNA against p16 before measuring the mRNA expression of proliferation, senescence, and fibrosis markers. p16 and miR-34a increased but SIRT1 decreased in Mdr2/ mice and PSC human liver samples compared to controls. p16 immunoreactivity and biliary senescence and SASP levels increased in Mdr2/ mice but decreased in Mdr2/ mice treated with p16 Vivo-Morpholino. The increase in IBDM and hepatic fibrosis (observed in Mdr2/ mice) returned to normal values in Mdr2/ mice treated with p16 Vivo-Morpholino. TGF-1 immunoreactivity and biliary SASPs levels were higher in Mdr2/ compared to those of WT mice but returned to normal values in Mdr2/ mice treated with p16 Vivo-Morpholino. The expression of fibrosis/senescence markers decreased in cholangiocytes from Mdr2/ mice treated with p16 Vivo-Morpholino (compared to Mdr2/ mice) and in IMCLs (after p16 silencing) compared to controls. Modulation of the TGF-1/miR-34a/SIRT1 axis may be important in the management of PSC phenotypes.Item The EGLN-HIF O2-Sensing System: Multiple Inputs and Feedbacks(Cell Press, 2017-06-15) Ivan, Mircea; Kaelin, William G., Jr.; Medicine, School of MedicineItem Endocervical miRNA Expression Profiles in Women Positive for Chlamydia trachomatis with Clinical Signs and/or Symptoms Are Distinct from Those in Women Positive for Chlamydia trachomatis without Signs and Symptoms(American Society for Microbiology, 2020-09-18) Batteiger, Teresa A.; Spencer, Nicole; Washam, Charity L.; Byrum, Stephanie; Eledge, Michael; Batteiger, Byron E.; Rank, Roger G.; Yeruva, Laxmi; Medicine, School of MedicineChlamydia trachomatis is the leading cause of sexually transmitted infections that may progress to pelvic inflammatory disease and infertility. No effective vaccine exists for Chlamydia, nor are there biomarkers available that readily predict disease progression. In this cross-sectional pilot study, we recruited symptomatic and asymptomatic women with C. trachomatis (CT) infection and asymptomatic, uninfected control women from an urban sexually transmitted disease clinic to determine if there were differences in microRNA (miRNA) expression. Infected women with signs and/or symptoms (CTSS) have distinct miRNA profiles compared to asymptomatic infected women (CTNS). In the CTSS group, miR-142 and -147 showed 2.2- to 6.9-fold increases in expression. In the CTNS group, miR-449c, -6779, -519d, -449a, and -2467 showed 3.9- to 9.0-fold increases in expression. In the CTNS group, cyclins and cell cycle regulation and IL-17 pathways were likely downregulated, while the same signaling pathways were upregulated in the CTSS group. In addition, in the CTSS group, additional inflammatory pathways associated with TNFR1 and IL-8 appear to be upregulated. The miRNA expression patterns differ between CT-infected symptomatic and asymptomatic women, and these differences may warrant further study.Item Hypermethylation of miRNA-17-92 cluster in peripheral blood mononuclear cells in diabetic retinopathy(Elsevier, 2022) Luo, Qianyi; Bhamidipalli, Surya Sruthi; Eckert, George J.; Bhatwadekar, Ashay D.; Ophthalmology, School of MedicineBackground and aims: Diabetic retinopathy (DR) is the most common complication of diabetes. The inflammatory milieu of diabetes results in changes throughout the body. This study asked whether epigenetic changes in peripheral blood mononuclear cells (PBMCs) reflect DR severity. Methods: PBMCs were separated from the whole blood of DR individuals using density gradient centrifugation. DNA was isolated, and methylation of micro-RNA (miR)-17-92 cluster was evaluated. Results: We observed that the miR-17-92 cluster was hypermethylated in DR individuals; specifically, this change was most remarkable with proliferative-DR (PDR). Conclusions: miR-17-92 methylation in PBMCs could help understand DR's pathogenesis and identify individuals at the risk of severe DR for early intervention.Item Integrative network analysis of rifampinregulated miRNAs and their functions in human hepatocytes(IOS, 2015) Li, Jin; Wang, Ying; Wang, Lei; Liang, Hong; Feng, Weixing; Meng, Xianglian; Cong, Wang; Liu, Yunlong; Department of Medical & Molecular Genetics, IU School of MedicineRifampin is an important drug used in the treatment of tuberculosis, and it increases the drug metabolism in human hepatocytes. Previous studies have shown that rifampin can indirectly influence drug deposition through the regulation of molecular interactions of miRNA, PXR and other genes. The potential functions of miRNAs associated with rifampin- induced drug disposition are poorly understood. In this study, significantly differentially expressed miRNAs (SDEM) were extracted and used to predict the miRNA-regulated co-expression target genes (MCeTG). Additionally, a miRNA-regulated co-expressed protein interaction network (MCePIN) was constructed for SDEM by extending from the protein interaction network (PIN). The functioning of the miRNAs were analyzed using GO analysis and KEGG pathway enrichment analysis. A total of 20 miRNAs belonging to SDEM were identified, and 632 miRNA-regulated genes were predicted. The MCePIN was constructed by extending from PIN, and 10 miRNAs and 33 genes that are relevant to 7 functions, including response to wounding, wound healing, response to drug, defense response, inflammatory response, liver development and drug metabolism, were discerned. The results provided by this study offer valuable insights into the effect of rifampin on miRNAs, genes and protein levels.Item Mapping the miRNA‐mRNA Interactome in Human Hepatocytes and Identification of Functional mirSNPs in Pharmacogenes(American Society for Clinical Pharmacology & Therapeutics, 2021-10) Powell, Nicholas R.; Zhao, Harrison; Ipe, Joseph; Liu, Yunlong; Skaar, Todd C.; Medicine, School of MedicineMiRNAs regulate the expression of hepatic genes involved in pharmacokinetics and pharmacodynamics. Genetic variants affecting miRNA binding (mirSNPs) have been associated with altered drug response, but previously used methods to identify miRNA binding sites and functional mirSNPs in pharmacogenes are indirect and limited by low throughput. We utilized the high-throughput chimeric-eCLIP assay to directly map thousands of miRNA-mRNA interactions and define the miRNA binding sites in primary hepatocytes. We then used the high-throughput PASSPORT-seq assay to functionally test 262 potential mirSNPs with coordinates overlapping the identified miRNA binding sites. Using chimeric-eCLIP, we identified a network of 448 miRNAs that collectively target 11,263 unique genes in primary hepatocytes pooled from 100 donors. Our data provide an extensive map of miRNA binding of each gene, including pharmacogenes, expressed in primary hepatocytes. For example, we identified the hsa-mir-27b-DPYD interaction at a previously validated binding site. A second example is our identification of 19 unique miRNAs that bind to CYP2B6 across 20 putative binding sites on the transcript. Using PASSPORT-seq, we then identified 24 mirSNPs that functionally impacted reporter mRNA levels. To our knowledge, this is the most comprehensive identification of miRNA binding sites in pharmacogenes. Combining chimeric-eCLIP with PASSPORT-seq successfully identified functional mirSNPs in pharmacogenes that may affect transcript levels through altered miRNA binding. These results provide additional insights into potential mechanisms contributing to interindividual variability in drug response.Item microRNA regulation of mammalian target of rapamycin expression and activity controls estrogen receptor function and RAD001 sensitivity(BioMed Central, 2014-10-06) Martin, Elizabeth C.; Rhodes, Lyndsay V.; Elliott, Steven; Krebs, Adrienne E.; Nephew, Kenneth P.; Flemington, Erik K.; Collins-Burow, Bridgette M.; Burow, Matthew E.; Department of Cellular & Integrative Physiology, School of MedicineBackground: The AKT/mammalian target of rapamycin (mTOR) signaling pathway is regulated by 17 α -estradiol (E2) signaling and mediates E2-induced proliferation and progesterone receptor (PgR) expression in breast cancer. Methods and results: Here we use deep sequencing analysis of previously published data from The Cancer Genome Atlas to demonstrate that expression of a key component of mTOR signaling, rapamycin-insensitive companion of mTOR (Rictor), positively correlated with an estrogen receptor- α positive (ER α + ) breast tumor signature. Through increased microRNA-155 (miR-155) expression in the ER α + breast cancer cells we demonstrate repression of Rictor enhanced activation of mTOR complex 1 (mTORC1) signaling with both qPCR and western blot. miR-155-mediated mTOR signaling resulted in deregulated ER α signalingbothinculturedcells in vitro and in xenografts in vivo in addition to repressed PgR expression and act ivity.FurthermoreweobservedthatmiR-155 enhanced mTORC1 signaling (observed through western blot for increased phosphorylation on mTOR S2448) and induced inhibition of mTORC2 signaling (evident through repressed Rictor and tuberous sclerosis 1 (TSC1) gene expression). mTORC1 induced deregulation of E2 signaling was confirmed using qPCR and the mTORC1-specific inhibitor RAD001. Co-treatment of MCF7 breast cancer cells stably overexpressing miR-155 with RAD001 and E2 restored E2-induced PgR gene expression. RAD001 treatment of SCID/CB17 mice inhibited E2-induced tumorigenesis of the MCF7 miR-155 overexpressing cell line. Finally we demonstrated a strong positive correlation between Rictor and PgR expression and a negative correlation with Raptor expression in Luminal B breast cancer samples, a breast cancer histological subtype known for having an altered ER α -signaling pathway. Conclusions: miRNA mediated alterations in mTOR and ER α signaling establishes a new mechanism for altered estrogen responses independent of growth factor stimulation.
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