MicroRNA-195a-5p inhibits mouse medullary thymic epithelial cells proliferation by directly targeting Smad7.
Ontology highlight
ABSTRACT:
SUBMITTER: Guo D
PROVIDER: S-EPMC4885129 | biostudies-literature |
REPOSITORIES: biostudies-literature
Similar Datasets
Project description:Medullary thymic epithelial cells (mTECs) ectopically express a diversity of peripheral tissue-restricted antigens (PTAs) and provide unique cues for the expansion, maturation and selection of a repertoire of functionally diverse T lymphocytes. Genetic deletion of all mature microRNAs in thymic epithelial cells (TECs) results in premature thymic involution, progressive disorganisation of the thymic epithelium, and alteration in thymic T cell lineage commitment, consequently eliciting autoimmune disorders. In the present study, we identified that microRNA-449a (miR-449a), a member of miR-449 cluster, regulated mTEC differentiation. Expression of miR-449a was induced by RANK ligand in mouse fetal thymus. In in vitro studies, overexpression of miR-449a induced thymic epithelial progenitor cells (TEPCs) differentiation into mature mTECs. Despite abundant expression of miR-449a in developing thymus, miR-449a-mutant mice exhibited normal thymic development. This might be partially due to in miR-449a-mutant thymus the up-regulation of miR-34a which shared similar seed sequence with miR-449a. However, thymic expression of miR-449/34 sponge which was able to neutralize the function of miR-449/34 family members significantly reduced the number of mature Ly51-MHCIIhi mTECs. Taken together, our data suggested that miR-449a modulated mTEC differentiation, and members of miR-34 cluster functioned redundantly to rescue miR-449a deficiency in thymus development.
| S-EPMC5698406 | biostudies-literature
Project description:BackgroundPrevious studies showed that miR-195a-5p was among the most abundant microRNAs (miRNAs) expressed in the kidney.MethodsLentivirus silencing of tumor necrosis factor-α (TNF) was performed in vivo and in vitro. Luciferase reporter assays confirmed that bumetanide-sensitive Na+-K+-2Cl- cotransporter isoform A (NKCC2A) mRNA is targeted and repressed by miR-195a-5p. Radiotelemetry was used to measure mean arterial pressure.ResultsTNF upregulates mmu-miR-195a-5p, and -203 and downregulates mmu-miR-30c and -100 in the medullary thick ascending limb of male mice. miR-195a-5p was >3-fold higher in the renal outer medulla of mice given an intrarenal injection of murine recombinant TNF, whereas silencing TNF inhibited miR-195a-5p expression by ≈51%. Transient transfection of a miR-195a-5p mimic into medullary thick ascending limb cells suppressed NKCC2A mRNA by ≈83%, whereas transfection with Anti-miR-195a-5p increased NKCC2A mRNA. Silencing TNF in medullary thick ascending limb cells prevented increases in miR-195 induced by 400 mosmol/kg H2O medium, an effect reversed by transfection with a miR-195a-5p mimic. Expression of phosphorylated NKCC2 increased 1.5-fold in medullary thick ascending limb cells transfected with Anti-miR-195a-5p and a miR-195a-5p mimic prevented the increase, which was induced by silencing TNF in cells exposed to 400 mosmol/kg H2O medium after osmolality was increased by adding NaCl. Intrarenal injection of TNF suppressed NKCC2A mRNA, whereas injection of miR-195a-5p prevented the increase of NKCC2A mRNA abundance and phosphorylated NKCC2 expression when TNF was silenced. Intrarenal injection with miR-195a-5p markedly attenuated MAP after renal silencing of TNF in mice given 1% NaCl.ConclusionsThe study identifies miR-195a-5p as a salt-sensitive and TNF-inducible miRNA that attenuates NaCl-mediated increases in blood pressure by inhibiting NKCC2A.
| S-EPMC9852070 | biostudies-literature
Project description:BackgroundMicroRNAs can be used in the prognosis of malignancies; however, their regulatory mechanisms are unknown, especially in pancreatic ductal adenocarcinoma (PDAC).MethodsIn 120 PDAC specimens, miRNA levels were assessed by quantitative real time polymerase chain reaction (qRT-PCR). Then, the role of miR-29b-2-5p in cell proliferation was evaluated both in vitro (Trypan blue staining and cell cycle analysis in the two PDAC cell lines SW1990 and Capan-2) and in vivo using a xenograft mouse model. Next, bioinformatics methods, a luciferase reporter assay, Western blot, and immunohistochemistry (IHC) were applied to assess the biological effects of Cbl-b inhibition by miR-29b-2-5p. Moreover, the relationship between Cbl-b and p53 was evaluated by immunoprecipitation (IP), Western blot, and immunofluorescence.ResultsFrom the 120 PDAC patients who underwent surgical resection, ten patients with longest survival and ten with shortest survival were selected. We found that high miR-29b-2-5p expression was associated with good prognosis (p = 0.02). The validation cohort confirmed miR-29b-2-5p as an independent prognostic factor in PDAC (n = 100, 95% CI = 0.305-0.756, p = 0.002). Furthermore, miR-29b-2-5p inhibited cell proliferation, induced cell cycle arrest, and promoted apoptosis both in vivo and in vitro. Interestingly, miR-29b-2-5p directly bound the Cbl-b gene, down-regulating its expression and reducing Cbl-b-mediated degradation of p53. Meanwhile, miR-29b-2-5p expression was negatively correlated with Cbl-b in PDAC tissues (r = - 0.33, p = 0.001).ConclusionsTaken together, these findings indicated that miR-29b-2-5p improves prognosis in PDAC by targeting Cbl-b to promote p53 expression, and would constitute an important prognostic factor in PDAC.
| S-EPMC6019739 | biostudies-literature
Project description:BACKGROUND:Glioma is the most common malignant tumor in the adult human brain and has one of the lowest patient survival rates. MicroRNAs (miRNAs) play important roles in the development of cancers, including glioma, and potentially have valuable therapeutic applications in glioma; however, their specific functions and mechanisms of action have yet to be fully defined. Here, we report that miR-129-5p directly targets DNA (cytosine-5)-methyltransferase 3A (DNMT3A) and functions as a tumor-suppressor in glioma. METHOD:We analyzed the expression profiles of miR-129-5p and DNMT3A in glioma-related databases. Quantitative reverse transcription-PCR was applied to detect the level of miR-129-5p in glioma specimens and cell lines. Western blotting was applied to detect the level of DNMT3A. We examined the effect of miR-129-5p on the cell cycle and proliferation of glioma cells using CCK-8 and EDU assays and flow cytometry. TargetScan software predicted DNMT3A to be a target of miR-129-5p, which we confirmed by means of luciferase reporter assays and rescue experiments. RESULT:miR-129-5p was expressed at low levels in glioma and negatively correlated with glioma grade. Over-expression of miR-129-5p in U87and LN229 cells inhibited proliferation and blocked the cell cycle in G1 Phase. DNMT3A is a direct target of miR-129-5p, and miR-129-5p affects glioma cell proliferation by targeting DNMT3A. CONCLUSION:Taken together, our results demonstrate that miR-129-5p plays a significant role in glioma suppression through inhibition of DNMT3A, which may provide a novel therapeutic strategy for treatment of glioma and other DNMT3A-driven cancers.
| S-EPMC6176228 | biostudies-literature
Project description:Glioma accounts for the majority of primary malignant brain tumors in adults and is highly aggressive. Although various therapeutic approaches have been applied, outcomes of glioma treatment remain poor. Acquiring a better understanding of the pathogenic mechanisms is essential to the design of effective therapeutic strategies. Previous studies have found that miR-520d-5p was negatively correlated with glioma grade, but its role and mechanism in glioma progression remain largely unknown. In the present study, we reported that miR-520d-5p directly targeted the Pituitary Tumor Transforming Gene 1 (PTTG1) and functioned as a tumor-suppressor in glioma. The expression of miR-520d-5p in glioma cells and specimens were detected by Quantitative reverse transcription-PCR and Fluorescence in situ hybridization (FISH). The effects of miR-520d-5p on glioma progression was examined by cell-counting kit 8, colony formation, 5-ethynyl-2-deoxyuridine (EDU) and flow cytometry assays. Using bioinformatics and luciferase reporter assays, we identified PTTG1 as a novel and direct target of miR-520d-3p. A xenograft model was used to study the effect of miR-520d-5p on tumor growth and angiogenesis. We found that miR-520d-5p expression was significantly decreased in glioma cell lines and tissues. Overexpression of miR-520d-5p showed a significant inhibitory effect on cell proliferation and accompanied cell cycle G0/G1 arrest in U87-MG and LN229 glioma cells. PTTG1 was a novel and direct target of miR-520d-5p, and the protein expression of PTTG1 was markedly reduced after overexpression of miR-520d-5p in U87-MG and LN229 cells. Overexpression of PTTG1 reversed the inhibitory effect of miR-520d-5p on glioma cell proliferation. In vivo studies confirmed that miR-520d-5p overexpression retarded the growth of U87 xenograft tumors, which was accompanied by reduced expression of PTTG1. In conclusion, these results provide compelling evidence that miR-520d-5p functions as an anti-onco-miRNA, which is important in inhibiting cell proliferation in GBM, and its anti-oncogenic effects are mediated chiefly through direct suppression of PTTG1 expression. Therefore, we suggest that miR-520d-5p is a potential candidate for the prevention of glioblastoma.
| S-EPMC5714772 | biostudies-literature
Project description:Thymic epithelial cells (TECs) support T cell development in the thymus. Cortical thymic epithelial cells (cTECs) facilitate positive selection of developing thymocytes whereas medullary thymic epithelial cells (mTECs) facilitate the deletion of self-reactive thymocytes in order to prevent autoimmunity. The mTEC compartment is highly dynamic with continuous maturation and turnover, but the genetic regulation of these processes remains poorly understood. MicroRNAs (miRNAs) are important regulators of TEC genetic programs since miRNA-deficient TECs are severely defective. However, the individual miRNAs important for TEC maintenance and function and their mechanisms of action remain unknown. Here, we demonstrate that miR-205 is highly and preferentially expressed in mTECs during both thymic ontogeny and in the postnatal thymus. This distinct expression is suggestive of functional importance for TEC biology. Genetic ablation of miR-205 in TECs, however, neither revealed a role for miR-205 in TEC function during homeostatic conditions nor during recovery from thymic stress conditions. Thus, despite its distinct expression, miR-205 on its own is largely dispensable for mTEC biology.
| S-EPMC4535774 | biostudies-literature
Project description:Despite the clear distinction between cortical (cTECs) and medullary thymic epithelial cells (mTECs) in physiology, the cell of origin of thymic carcinomas (TCs) and other thymic epithelial tumors remained enigmatic. We addressed this issue by focusing on AIRE, an mTEC-specific transcriptional regulator that is required for immunological self-tolerance. We found that a large proportion of TCs expressed AIRE with typical nuclear dot morphology by immunohistochemistry. AIRE expression in TCs was supported by the RNA-seq data in the TCGA-THYM database. Furthermore, our bioinformatics approach to the recent single-cell RNA-seq data on human thymi has revealed that TCs hold molecular characteristics of multiple mTEC subpopulations. In contrast, TCs lacked the gene signatures for cTECs. We propose that TCs are tumors derived from mTECs.
| S-EPMC10166898 | biostudies-literature
Project description:TRAF6, an E3 ubiquitin protein ligase, plays a critical role in T cell tolerance by regulating medullary thymic epithelial cell (mTEC) development. mTECs regulate T cell tolerance by ectopically expressing self-antigens and eliminating autoreactive T cells in the thymus. Here we show that mice with mTEC depletion due to conditional deletion of Traf6 expression in murine thymic epithelial cells (Traf6?TEC mice) showed a surprisingly narrow spectrum of autoimmunity affecting the liver. The liver inflammation in Traf6?TEC mice exhibited all the histological and immunological characteristics of human autoimmune hepatitis (AIH). The role of T cells in AIH establishment was supported by intrahepatic T cell population changes and AIH development after transfer of liver T cells into immunodeficient mice. Despite a 50% reduction in natural Treg thymic output, peripheral tolerance in Traf6?TEC mice was normal, whereas compensatory T regulatory mechanisms were evident in the liver of these animals. These data indicate that mTECs exert a cell-autonomous role in central T cell tolerance and organ-specific autoimmunity, but play a redundant role in peripheral tolerance. These findings also demonstrate that Traf6?TEC mice are a relevant model with which to study the pathophysiology of AIH, as well as autoantigen-specific T cell responses and regulatory mechanisms underlying this disease.
| S-EPMC3726151 | biostudies-literature
Project description:Thymic epithelial cells are one of the main components of the thymic microenvironment required for T-cell development. In this work, we describe an efficient method free of enzymatic and Facs-sorted methods to culture human medullary thymic epithelial cells without affecting the cell phenotypic, physiologic and functional features. Human medulla thymic epithelial cells (mTECs) are obtained by culturing thymic biopsies explants. After 7 days of primo-culture, mTECs keep their ability to express key molecules involved in immune tolerance processes such as autoimmune regulator, tissue-specific antigens, chemokines, and cytokines. In addition, the cells sensor their cultured environment and consequently adjust their gene expression network. Therefore, we describe and provide a human mTEC model that may be used to test the effect of various molecules on thymic epithelial cell homeostasis and physiology. This method should allow the investigations of the specificities and the knowledge of human mTECs in normal or pathological conditions and therefore discontinue the extrapolations done on the murine models.
| S-EPMC6064927 | biostudies-literature
Project description:Background:MicroRNAs (miRNAs) are important regulators for cancer cell proliferation. miR-585 has been shown to inhibit the proliferation of several types of cancer, however, little is known about its role in human glioma cells. Methods:miR-585 levels in human glioma clinical samples and cell lines were examined by quantitative real-time PCR (qRT-PCR) analysis. Cell proliferation was measured by Cell Counting Kit-8 (CCK-8) and EdU incorporation assays in vitro. For in vivo investigations, U251 cells were intracranially inoculated in BALB/c nude mice and xenografted tumors were visualized by magnetic resonance imaging (MRI). Results:miR-585 expression is downregulated in human glioma tissues and cell lines compared with non-cancerous counterparts. Additionally, miR-585 overexpression inhibits and its knockdown promotes human glioma cell proliferation in vitro. Moreover, miR-585 overexpression also inhibits the growth of glioma xenografts in vivo, suggesting that miR-585 may act as a tumor suppressor to inhibit the proliferation of human glioma. Furthermore, miR-585 directly targets and decreases the expression of oncoprotein murine double minute 2 (MDM2). More importantly, the restoration of MDM2 via enforced overexpression markedly rescues miR-585 inhibitory effect on human glioma cell proliferation, thus demonstrating that targeting MDM2 is a critical mechanism by which miR-585 inhibits human glioma cell proliferation. Conclusions:Our study unveils the anti-proliferative role of miR-585 in human glioma cells, and also implicates its potential application in clinical therapy.
| S-EPMC7523344 | biostudies-literature