Non-coding RNA Taurine Upregulated Gene 1 Research Articles

M6A-mediated upregulation of lncRNA TUG1 in liver cancer cells regulates the antitumor response of CD8+ T cells and phagocytosis of macrophages.

Tumor immune evasion relies on the crosstalk between tumor cells and adaptive/innate immune cells. Immune checkpoints play critical roles in the crosstalk, and immune checkpoint inhibitors have achieved promising clinical effects. The long non-coding RNA taurine-upregulated gene 1 (TUG1) is upregulated in hepatocellular carcinoma (HCC). However, how TUG1 is upregulated and the effects on tumor immune evasion are incompletely understood. Here, METTL3-mediated m6A modification led to TUG1 upregulation is demonstrated. Knockdown of TUG1 inhibited tumor growth and metastasis, increased the infiltration of CD8+ T cells and M1-like macrophages in tumors, promoted the activation of CD8+ T cells through PD-L1, and improved the phagocytosis of macrophages through CD47. Mechanistically, TUG1 regulated PD-L1 and CD47 expressions by acting as a sponge of miR-141 and miR-340, respectively. Meanwhile, TUG1 interacted with YBX1 to facilitate the upregulation of PD-L1 and CD47 transcriptionally, which ultimately regulated tumor immune evasion. Clinically, TUG1 positively correlated with PD-L1 and CD47 in HCC tissues. Moreover, the combination of Tug1-siRNA therapy with a Pdl1 antibody effectively suppressed tumor growth. Therefore, the mechanism of TUG1 in regulating tumor immune evasion is revealed and can inform existing strategies targeting TUG1 for enhancing HCC immune therapy and drug development.

Alleviation of Angiotensin II-Induced Vascular Endothelial Cell Injury Through Long Non-coding RNA TUG1 Inhibition.

Hypertension damages endothelial cells, causing vascular remodelling. It is caused by Ang II-induced endothelial cell (EC) destruction. The long noncoding RNA (lncRNAs) are emerging regulators of endothelium homeostasis. Injured endothelium expresses lncRNA taurine-upregulated gene 1 (TUG1), which may mediate endothelial cell damage, proliferation, apoptosis, and autophagy and contribute to cardiovascular disease. However, uncertainty surrounds the function of lncRNA TUG1, on arterial endothelium cell damage. This research aimed to investigate the role and mechanism of lncRNA TUG1 in vascular endothelial cell injury. A microarray analysis of lncRNA human gene expression was used to identify differentially expressed lncRNAs in human umbilical vein endothelial cell (HUVEC) cultures. The viability, apoptosis, and migration of Ang II-treated HUVECs were then evaluated. In order to investigate the role of lncRNA TUG1 in hypertension, qRT-PCR, western blotting, and RNA-FISH were used to examine the expression of TUG1 in SHR mice. Ang II-activated HUVECs and SHR rats' abdominal aortas highly express the lncRNA TUG1. LncRNA TUG1 knockdown in HUVECs could increase cell viability, reduce apoptosis, and produce inflammatory factors. In SHR rat abdominal aortas, lncRNA TUG1 knockdown promoted proliferation and inhibited apoptosis. HE spotting showed that lncRNA TUG1 knockdown improved SHR rats' abdominal aorta shape. lncRNA TUG1 knockdown promotes miR-9- 5p, which inhibits CXCR4 following transcription. The lncRNA TUG1/miR-9-5p/CXCR4 axis and vascular cell injury were also examined. MiR-9-5p silencing or CXCR4 overexpression lowered cell survival, apoptosis, and lncRNA TUG1-induced IL-6 and NO expression. lncRNA TUG1 suppression could reduce Ang II-induced endothelial cell damage by regulating and targeting miR-9-5p to limit CXCR4 expression and open new vascular disease research pathways.

LncRNA TUG1 mediates microglial inflammatory activation by regulating glucose metabolic reprogramming

Microglia are natural immune cells in the central nervous system, and the activation of microglia is accompanied by a reprogramming of glucose metabolism. In our study, we investigated the role of long non-coding RNA taurine-upregulated gene 1 (TUG1) in regulating microglial glucose metabolism reprogramming and activation. BV2 cells were treated with Lipopolysaccharides (LPS)/Interferon-γ (IFN-γ) to establish a microglial activation model. The glycolysis inhibitor 2-Deoxy-D-glucose (2-DG) was used as a control. The expression levels of TUG1 mRNA and proinflammatory cytokines such as Interleukin-1β (IL-1β), Interleukin -6, and Tumor Necrosis Factor-α mRNA and anti-inflammatory cytokines such as IL-4, Arginase 1(Arg1), CD206, and Ym1 were detected by RT-qPCR. TUG1 was silenced using TUG1 siRNA and knocked out using CRISPR/Cas9. The mRNA and protein expression levels of key enzymes involved in glucose metabolism, such as Hexokinase2, Glyceraldehyde-3-phosphate dehydrogenase (GAPDH), Lactate dehydrogenase, Glucose 6 phosphate dehydrogenase, and Pyruvate dehydrogenase (PDH), were determined by RT-qPCR and Western blotting. The glycolytic rate of microglial cells was measured using Seahorse. Differential metabolites were determined by metabolomics, and pathway enrichment was performed using these differential metabolites. Our findings revealed that the expression of TUG1 was elevated in proinflammatory-activated microglia and positively correlated with the levels of inflammatory factors. The expression of anti-inflammatory cytokines such as IL-4, Arg1, CD206, and Ym1 were decreased when induced with LPS/IFN-γ. However, this decrease was reversed by the treatment with 2-DG. Silencing of GAPDH led to an increase in the expression of TUG1 and inflammatory factors. TUG1 knockout (TUG1KO) inhibited the expression of glycolytic key enzymes and promoted the expression of oxidative phosphorylation key enzymes, shifting the metabolic profile of activated microglia from glycolysis to oxidative phosphorylation. Additionally, TUG1KO reduced the accumulation of metabolites, facilitating the restoration of the tricarboxylic acid cycle and enhancing oxidative phosphorylation in microglia. Furthermore, the downregulation of TUG1 was found to reduce the expression of both proinflammatory and anti-inflammatory cytokines under normal conditions. Interestingly, when induced with LPS/IFN-γ, TUG1 downregulation showed a potentially beneficial effect on microglia in terms of inflammation. Downregulation of TUG1 expression inhibits glycolysis and facilitates the shift of microglial glucose metabolism from glycolysis to oxidative phosphorylation, promoting their transformation towards an anti-inflammatory phenotype and exerting anti-inflammatory effects in BV2.

Abstract 5613: Study of long non-coding RNA TUG1 kinetics under replication stress conditions in cancer cell

Abstract Long non-coding RNAs (lncRNAs) are transcripts longer than 200 nucleotides that are not translated into proteins. In contrast to protein-coding mRNAs, certain lncRNAs carry out their functions within the nucleus. A detailed elucidation of the kinetics of lncRNAs contributes to a comprehensive understanding of their bona fide biological characteristics. Consequently, advancements in the in vivo visualization of lncRNAs have continued. Currently, various techniques, including RNA imaging technologies, have been employed to facilitate real-time tracking and visualization of RNA molecules within living cells. Taurine upregulated gene 1 (TUG1) is an oncogenic lncRNA, playing a pivotal role in cancer cells by resolving R-loops formed at stalled replication forks, particularly under replication stress conditions such as Hydroxyurea (HU) treatment. Despite its significance, the dynamic regulation of TUG1 under replication stress conditions remains largely unknown. In this study, we developed a stem loop-based live imaging system enabling real-time visualization of TUG1, providing insights into its subcellular localization and dynamic roles in physiological contexts. Upon treatment with HU, a chemical that interferes with replication, TUG1 expression was rapidly upregulated in the nucleus within 20 minutes. Additionally, we observed TUG1 molecules relocating close to the nuclear membrane. Considering the reported relocation of collapsed forks to the nuclear pore complex, this suggests that TUG1 may be involved in this relocation structure. These data indicate that TUG1 is associated with the fork restore mechanism occurring at the relocated collapsed forks, and the current live-cell imaging system holds potential for further uncovering the critical roles of TUG1 in cancer cells. Our stem loop-based imaging may contribute to a more precise understanding of RNA dynamics in live cells. Citation Format: Tomoya Fujita, Miho Suzuki, Osamu Masui, Keiko Shinjo, Yutaka Kondo. Study of long non-coding RNA TUG1 kinetics under replication stress conditions in cancer cell [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 5613.

Abstract 3286: Synergistic impact of long non-coding RNA TUG1 depletion in overcoming temozolomide chemoresistance in glioblastoma

Abstract Glioblastoma (GBM) stands out as the most prevalent and aggressive primary brain tumor in adults, marked by a high mortality rate. Standard therapy involves temozolomide (TMZ) chemotherapy, an alkylating agent. However, most cases develop resistance to TMZ, necessitating the development of new treatment options to overcome TMZ-resistant GBM. Long non-coding RNAs (lncRNAs) constitute a class of RNA molecules that, despite not encoding proteins, play pivotal roles in regulating diverse cellular processes. Overexpression of specific lncRNAs in cancer is linked to crucial aspects of cancer progression, such as cell proliferation, apoptosis, and metastasis. Taurine upregulated gene 1 (TUG1) is a highly expressed lncRNA in GBM, playing a crucial role in preventing excessive DNA replication stress and associated DNA damage (Nat Commun 2023).This study aimed to investigate the combined effects of TUG1 depletion and TMZ in TMZ-resistant GBM. First, we established a TMZ-resistant U251MG cell line, U251MG-R, characterized by a low DNA methylation level of the O6-methylguanine-DNA methyltransferase (MGMT) promoter. We observed that TMZ increased DNA replication stress in the U251MG-R. Depleting TUG1 by using antisense oligonucleotide (TUG1-ASO) sensitized U251MG-R cells to TMZ. Treatment with TMZ or TUG1-ASO alone inhibited cell proliferation, with the most significant inhibition observed when both were combined. Next, we employed a xenograft mouse model to evaluate the efficacy of intravenous TUG1-ASO treatment coupled with a tumor-specific drug delivery system (antiTUG1-DDS). The combination of antiTUG1-DDS with TMZ displayed the most effective suppression of tumor growth compared to either TMZ or antiTUG1-DDS alone. Targeted therapy aimed at TUG1 may be a promising approach for overcoming TMZ resistance in GBM. Citation Format: Hidekazu Kito, Yuji Kibe, Miho Suzuki, Keiko Shinjo, Yutaka Kondo. Synergistic impact of long non-coding RNA TUG1 depletion in overcoming temozolomide chemoresistance in glioblastoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 3286.

The study of long noncoding RNA TUG 1 and ZEB2-AS1 expression in newly diagnosed Egyptian adult acute myeloid leukemia patients

BackgroundThe hematopoietic malignancy acute myeloid leukemia is a fatal disease with poor clinical prognoses. Long non-coding RNA taurine-upregulated gene1 (lncRNA TUG1) and zinc finger E-box binding homeobox 2 antisense RNA1 (lncRNA ZEB2-AS1) are reported to participate in the development and progression of different types of malignancies. The goal of the current study was to evaluate the prognostic value of the lncRNAs TUG1 and ZEB2-AS1 as well as their various expression patterns in newly diagnosed Egyptian adult acute myeloid leukemia patients.MethodsWe assessed the expression levels of both lncRNA TUG1 and lncRNA ZEB2-AS1 using the quantitative real-time reverse transcription polymerase chain reaction technique (qRT-PCR) in 80 newly diagnosed AML patients and 20 healthy subjects.ResultslncRNA TUG1 expression was significantly higher in the AML cases compared to the controls (P < 0.001), whereas lncRNA ZEB2-AS1 expression was considerably lower in the AML cases in comparison with the controls (P < 0.001). The expression levels of the lncRNAs ZEB2-AS1 and TUG1 exhibited a significantly positive association in the AML group (P < 0.001). There was no difference in overall survival (OS) and disease-free survival (DFS) between the groups with low and high lncRNA TUG1 expression (P = 0.139 and 0.918, respectively). Furthermore, the AML cases with higher lncRNA ZEB2-AS1 expression levels had shorter DFS than patients with lower lncRNA ZEB2-AS1 expression levels (P = 0.014), while OS did not significantly differ between the studied cases with lower and higher lncRNA ZEB2-AS1 expression (P = 0.589).ConclusionOverexpression of lncRNA TUG1 could serve as a diagnostic biomarker for Egyptian adult AML cases, while lncRNA ZEB2-AS1 high expression could be regarded as an indicator of poor outcome in Egyptian adult AML studied cases.

Abstract 6205: Visualizing dynamics of long non-coding RNA TUG1 in live glioblastoma cells

Abstract Long non-coding RNAs (lncRNAs) are transcripts longer than 200 nucleotides that are not translated into proteins. lncRNA TUG1 (taurine upregulated gene 1) is highly expressed in various cancers, including glioblastoma. Previously we found that TUG1 is an essential molecule for cancer cells to cope with excessive replication stress in the S phase. Albeit its importance to cell cycle-related function, how it is dynamically regulated during the cell cycle is entirely unknown. Here, we established a system visualizing endogenous TUG1 molecules in live cells. TUG1 was tagged with stem-loop motifs recognized by a specific binding protein fused with GFP. We tracked TUG1 RNA by the GFP signal for 22 hours in T98G glioblastoma cells and found that the expression started from the later G1 phase. When cells were treated with Hydroxy Urea, a chemical that interferes with replication and increases replication stress, the expression of TUG1 was further upregulated in the S phase within 20 mins. We also observed some TUG1 molecules accumulated in several nuclear locations. It may indicate that TUG1 assembles to protect damaged DNA loci efficiently. Our results suggest that the expression of TUG1 is regulated in a cell cycle-dependent manner and is strongly connected with its function of TUG1. The current live-cell imaging system could help further discover the critical roles of TUG1 in cancer cells. Citation Format: Ayaka Minematsu. Visualizing dynamics of long non-coding RNA TUG1 in live glioblastoma cells [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 6205.

Long Non-Coding RNA TUG1 Attenuates Insulin Resistance in Mice with Gestational Diabetes Mellitus via Regulation of the MicroRNA-328-3p/SREBP-2/ERK Axis.

Long non-coding RNAs (lncRNAs) have been illustrated to contribute to the development of gestational diabetes mellitus (GDM). In the present study, we aimed to elucidate how lncRNA taurine upregulated gene 1 (TUG1) influences insulin resistance (IR) in a high-fat diet (HFD)-induced mouse model of GDM. We initially developed a mouse model of HFD-induced GDM, from which islet tissues were collected for RNA and protein extraction. Interactions among lncRNA TUG1/microRNA (miR)-328-3p/sterol regulatory element binding protein 2 (SREBP-2) were assessed by dual-luciferase reporter assay. Fasting blood glucose (FBG), fasting insulin (FINS), homeostasis model assessment of insulin resistance (HOMA-IR), HOMA pancreatic β-cell function (HOMA-β), insulin sensitivity index for oral glucose tolerance tests (ISOGTT) and insulinogenic index (IGI) levels in mouse serum were measured through conducting gain- and loss-of-function experiments. Abundant expression of miR-328 and deficient expression of lncRNA TUG1 and SREBP-2 were characterized in the islet tissues of mice with HFD-induced GDM. LncRNA TUG1 competitively bound to miR-328-3p, which specifically targeted SREBP-2. Either depletion of miR-328-3p or restoration of lncRNA TUG1 and SREBP-2 reduced the FBG, FINS, HOMA-β, and HOMA-IR levels while increasing ISOGTT and IGI levels, promoting the expression of the extracellular signal-regulated kinase (ERK) signaling pathway-related genes, and inhibiting apoptosis of islet cells in GDM mice. Upregulation miR-328-3p reversed the alleviative effects of SREBP-2 and lncRNA TUG1 on IR. Our study provides evidence that the lncRNA TUG1 may prevent IR following GDM through competitively binding to miR-328-3p and promoting the SREBP-2-mediated ERK signaling pathway inactivation.

Long noncoding RNA TUG1 decreases bladder cancer chemo-sensitivity toward doxorubicin through elevating KPNA2 expression and activating the PI3K/AKT pathway via adsorbing miR-582-5p.

Long noncoding RNA taurine-upregulated gene1 (TUG1) has been reported to be implicated in the chemo-resistance of bladder cancer. Hence, this study aimed to survey regulatory mechanism by which TUG1 regulates the chemo-resistance of bladder cancer cells to doxorubicin (DOX). Relative expression of TUG1, miR-582-5p, and karyopherin alpha 2 (KPNA2) was detected by qRT-PCR. The viability and proliferation of DOX-resistant bladder cancer cells were determined by 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide (MTT) assay. Protein levels were measured by western blot analysis. The apoptosis, migration, and invasion of DOX-resistant bladder cancer cells were determined by flow cytometry or transwell assays. The relationship between TUG1 or KPNA2 and miR-582-5p was verified by dual-luciferase reporter assay. TUG1 and KPNA2 were upregulated while miR-582-5p was downregulated in resistant bladder cancer tissues and cells. TUG1 inhibition elevated cell chemo-sensitivity, facilitated cell apoptosis, and curbed proliferation, migration, invasion, and autophagy of DOX-resistant bladder cancer cells. Also, TUG1 acted as a sponge for miR-582-5p, and miR-582-5p inhibitor reversed TUG1 knockdown-mediated influence on DOX chemo-sensitivity and malignant behaviors in DOX-resistant bladder cancer cells. Furthermore, miR-582-5p targeted KPNA2, and KPNA2 overexpression counteracted the inhibitory impact of miR-582-5p mimic on DOX chemo-resistance and malignant behaviors in DOX-resistant bladder cancer cells. Additionally, TUG1 silencing inactivated the PI3K/AKT pathway through sponging miR-582-5p. TUG1 sponged miR-582-5p to increase KPNA2 expression and activated the KPNA2/PI3K/AKT pathway, thereby elevating DOX chemo-resistance and malignant behaviors in bladder cancer cells.

Long noncoding RNA TUG1 induces angiogenesis of endothelial progenitor cells and dissolution of deep vein thrombosis.

ObjectiveLong non-coding RNA (lncRNA) essentially controls many physiological and pathological processes of deep vein thrombosis (DVT). Based on that, lncRNA taurine upregulated gene 1 (TUG1)-involved angiogenesis of endothelial progenitor cells (EPCs) and dissolution of DVT was explored.MethodsIn the in-vitro experiments, EPCs were engineered with mimic, inhibitor, siRNA, and plasmid, after which tube formation, proliferation, migration, and apoptosis were checked. In the in-vivo experiments, a DVT mouse model was established. Before the DVT operation, the mice were injected with agomir, antagomir, siRNA, and plasmid. Subsequently, thrombosis and damage to the femoral vein were pathologically evaluated. TUG1, miR-92a-3p, and 3-Hydroxy-3-methylglutaryl coenzyme A reductase (Hmgcr) expression in the femoral vein was tested. The relationship between TUG1, miR-92a-3p, and Hmgcr was validated.ResultsDVT mice showed suppressed TUG1 and Hmgcr expression, and elevated miR-92a-3p expression. In EPCs, TUG1 overexpression or miR-92a-3p inhibition promoted cellular angiogenesis, whereas Hmgcr silencing blocked cellular angiogenesis. In DVT mice, elevated TUG1 or inhibited miR-92a-3p suppressed thrombosis and damage to the femoral vein whilst Hmgcr knockdown acted oppositely. In both cellular and animal models, TUG1 overexpression-induced effects could be mitigated by miR-92a-3p up-regulation. Mechanically, TUG1 interacted with miR-92a-3p to regulate Hmgcr expression.ConclusionEvidently, TUG1 promotes the angiogenesis of EPCs and dissolution of DVT via the interplay with miR-92a-3p and Hmgcr.Supplementary InformationThe online version contains supplementary material available at 10.1186/s12959-022-00413-y.

LncRNA TUG1 Promoted Stabilization of BAG5 by Binding DDX3X to Exacerbate Ketamine-Induced Neurotoxicity.

As a clinically widely used anesthetic, ketamine (KET) has been reported to cause neurotoxicity in patients. Our work aimed to probe the function of long-chain non-coding RNA taurine-upregulated gene 1 (lncRNA TUG1) in KET-induced neurotoxicity. HT22 cells were subjected to KET to build the cell model. 3-(4, 5-Dimethylthiazolyl2)-2, 5-diphenyltetrazolium bromide (MTT) assay was employed to determine cell viability. Additionally, cell apoptosis was evaluated by flow cytometry. The binding relationships among TUG1, DEAD-box RNA helicase 3X (DDX3X), and Bcl-2-associated athanogene 5 (BAG5) were verified by RIP and RNA pull-down assays. Cell viability was impaired and cell apoptosis was increased in KET-treated HT22 cells accompanied by increased TUG1, DDX3X, and BAG5 expressions. TUG1 knockdown dramatically enhanced cell viability and repressed the of KET-induced apoptosis in HT22 cells, while TUG1 overexpression presented the opposite effects. In addition, we found that TUG1 promoted DDX3X expression via directly binding with DDX3X. As expected, DDX3X overexpression abolished the palliative effect of TUG1 knockdown on KET-induced neurotoxicity. Further research proved that TUG1 increased the stability of BAG5 through interacting with DDX3X. Finally, as expected, the moderating effect of TUG1 knockdown on KET-induced neuron injury was abolished by BAG5 overexpression. Taken together, TUG1 promoted BAG5 expression by binding DDX3X to exacerbate KET-induced neurotoxicity.

Silencing of Long Noncoding RNA TUG1 Ameliorates Atherosclerosis-Induced Myocardial Injury by Upregulating microRNA-30b-3p and Downregulating Brd4.

Long noncoding RNAs and microRNAs (miRNAs) are emerging biomarkers involved in human diseases, and we focused on the roles of long noncoding RNA taurine upregulated gene 1 (TUG1) and miR-30b-3p in the related mechanisms of atherosclerosis-induced myocardial injury. ApoE-deficient mice were fed with high-fat diet to establish atherosclerotic models and then were subjected to either TUG1 downregulation or miR-30b-3p upregulation treatment. The serum myocardial enzymes, inflammatory biomarkers, pathological changes, intramyocardial macrophage infiltration, and apoptosis of cardiomyocytes in atherosclerotic mice were determined. The expression of TUG1, miR-30b-3p, and bromodomain protein 4 (Brd4) in atherosclerotic models was evaluated. Moreover, the correlations of TUG1, miR-30b-3p, and Brd4 were verified. TUG1 and Brd4 were increased while miR-30b-3p was decreased in atherosclerotic mice. The silenced TUG1 or elevated miR-30b-3p attenuated atherosclerosis-induced myocardial injury mainly by reducing serum myocardial enzyme content and inflammatory response, improving pathological changes, and preventing macrophage infiltration and cardiomyocyte apoptosis in atherosclerotic mice. Mechanistically, TUG1 could competitively bind with miR-30b-3p to prevent the degradation of its target gene Brd4. This study reveals that the silencing of TUG1 ameliorates atherosclerosis-induced myocardial injury by upregulating miR-30b-3p and downregulating Brd4, which may provide novel targets for atherosclerosis treatment.

Long non-coding RNA Tug1 modulates mitochondrial and myogenic responses to exercise in skeletal muscle

BackgroundMitochondria have an essential role in regulating metabolism and integrate environmental and physiological signals to affect processes such as cellular bioenergetics and response to stress. In the metabolically active skeletal muscle, mitochondrial biogenesis is one important component contributing to a broad set of mitochondrial adaptations occurring in response to signals, which converge on the biogenesis transcriptional regulator peroxisome proliferator-activated receptor coactivator 1-alpha (PGC-1α), and is central to the beneficial effects of exercise in skeletal muscle. We investigated the role of long non-coding RNA (lncRNA) taurine-upregulated gene 1 (TUG1), which interacts with PGC-1α in regulating transcriptional responses to exercise in skeletal muscle.ResultsIn human skeletal muscle, TUG1 gene expression was upregulated post-exercise and was also positively correlated with the increase in PGC-1α gene expression (PPARGC1A). Tug1 knockdown (KD) in differentiating mouse myotubes led to decreased Ppargc1a gene expression, impaired mitochondrial respiration and morphology, and enhanced myosin heavy chain slow isoform protein expression. In response to a Ca2+-mediated stimulus, Tug1 KD prevented an increase in Ppargc1a expression. RNA sequencing revealed that Tug1 KD impacted mitochondrial Ca2+ transport genes and several downstream PGC-1α targets. Finally, Tug1 KD modulated the expression of ~300 genes that were upregulated in response to an in vitro model of exercise in myotubes, including genes involved in regulating myogenesis.ConclusionsWe found that TUG1 is upregulated in human skeletal muscle after a single session of exercise, and mechanistically, Tug1 regulates transcriptional networks associated with mitochondrial calcium handling, muscle differentiation and myogenesis. These data demonstrate that lncRNA Tug1 exerts regulation over fundamental aspects of skeletal muscle biology and response to exercise stimuli.

Long Noncoding RNA TUG1 Aggravates Cerebral Ischemia/Reperfusion Injury by Acting as a ceRNA for miR-3072-3p to Target St8sia2.

Long noncoding RNA taurine-upregulated gene 1 (TUG1) is considered to be involved in postischemic cerebral inflammation, whereas polysialic acid (polySia, PSA), the product of St8sia2, constitutes polysialylated neural adhesion cell molecule (PSA-NCAM) in both mice and humans and that cerebral PSA-NCAM level is elevated in neuronal progenitor cells in response to transient focal ischemia. Herein, we aim to identify novel miRNAs that bridge the functions of St8sia2 and TUG1 in ischemia-associated injuries. In both in vivo (C57BL/6J mouse ischemia/reperfusion, I/R model) and in vitro (mouse neuroblastoma N2A cell oxygen glucose deprivation/reoxygenation, OGD model) settings, we observed upregulated TUG1 and St8sia2 after the induction of ischemic injury, accompanied by reduced miR-3072-3p expression. We performed siRNA-induced TUG1 knockdown combined with the induction of ischemic injury; the results showed that inhibiting TUG1 expression led to the reduced infarct area and improved neurological deficit. Through bioinformatics analysis, miR-3072-3p was found to target both St8sia2 and TUG1, which was subsequently verified by the luciferase reporter system and RNA binding protein immunoprecipitation assay. Also, the addition of miR-3072-3p mimic/inhibitor resulted in reduced/elevated St8sia2 expression at the protein level. Further studies revealed that in both in vivo and in vitro settings, TUG1 bound competitively to miR-3072-3p to regulate St8sia2 expression and promote apoptosis. In summary, targeting the TUG1/miR-3072-3p/St8sia2 regulatory cascade, a novel cascade we identified in cerebral ischemia injury, may render feasible therapeutic possibilities for overcoming cerebral ischemic insults.

Effects of Long Noncoding RNA TUG1 (Taurine Up-Regulated Gene 1) on Growth and Metastasis of the Non-Small Cell Lung Cancer and Its Mechanism

Objective: Our research was to discuss effects and mechanism of lncRNA TUG1 in NSCLC by vitro study. Methods: A549 and H1299 cells were divided into NC, pcDNA 3.1 and lncRNA TUG1 groups. Measuring cell proliferation using CCK-8 assay, cell apoptosis by flow cytometry, invasion cell number by transwell and wound healing rate by wound healing assay. Relative gene and protein expressions by RT-qPCR and WB assay. Results: Compared with NC group, the cell proliferation rate, invasion cell number and wound healing rate were significantly depressed in A549 and H1299 cell lines (P &lt; 0.001, respectively). By RT-qPCR and WB assay, lncRNA TUG1 gene expression were significantly increased (P &lt; 0.001, respectively); E-cadherin gene and protein expression were significantly up-regulation, and N-cadherin and Vimentin gene and protein expressions were significantly depressed compared with those of NC group in A549 and H1299 cell lines (P &lt; 0.001, respectively). Conclusion: lncRNA TUG1 had effects to suppress NSCLC cell biological activities by regulation EMT relative gene and proteins expression in vivo study.

The renoprotective effects of gallic acid on cisplatin-induced nephrotoxicity through anti-apoptosis, anti-inflammatory effects, and downregulation of lncRNA TUG1.

Cisplatin, an antineoplastic drug used in cancer therapy, -induced nephrotoxicity mediated by the production of reactive oxygen species (ROS). Gallic acid (GA) is identified as an antioxidant substance with free radical scavenging properties. This research was designed to examine the ameliorative impact of GA caused by cisplatin-induced nephrotoxicity through apoptosis and long non-coding RNA (lncRNA) Taurine-upregulated gene 1 (TUG1) expression. Thirty-two male Sprague Dawley rats (200 - 220g) were randomly allocated to four groups: (1) control group; (2) rats treated with cisplatin (7.5mg/kg, i.p.) on the fourth day; and the two other groups include rats pretreated with GA (20 and 40mg/kg by gavage) for s7 days and cisplatin (7.5mg/kg, i.p.) at the fourth day. The rats were anesthetized and sacrificed for collecting samples, 72h after cisplatin administration. The blood samples were used to investigate biochemical factors and kidney tissue was evaluated for measuring oxidative stress and inflammatory factors and the gene expression of molecular parameters. The results indicated that GA administration increased the B-cell lymphoma-2 (Bcl-2) mRNA and lncRNA TUG1 expression, and reduced Bcl-2-associated x protein (Bax), and caspase-3 expression. Likewise, the TAC level increased, and kidney MDA content decreased by administration of GA. GA also decreased the inflammatory factor levels, including IL-1β and TNF-α. Moreover, GA led to the improvement of kidney dysfunction as evidenced by reducing plasma BUN (blood urea nitrogen) and Cr (creatinine). Taken together, GA could protect the kidney against cisplatin-induced nephrotoxicity through antioxidant, anti-inflammatory, and anti-apoptosis properties and reduction of lncRNA TUG1 expression.

Long non-coding RNA TUG1 sponges microRNA-9 to protect podocytes from high glucose-induced apoptosis and mitochondrial dysfunction via SIRT1 upregulation.

Podocyte apoptosis and mitochondrial dysfunction serve a major role in diabetic nephropathy progression. The present study revealed a molecular mechanism regulating podocyte apoptosis and mitochondrial dysfunction. In vitro models were established using conditionally immortalized mouse podocyte clonal cells treated with high glucose (HG). Reverse quantitative-transcription PCR were used to detect gene expression, western blotting and immunofluorescence were used to detect protein expression, Cell Counting Kit-8 was used to detect cell viability and flow cytometry was used to detect cell apoptosis. HG treatment in the mouse podocyte clonal cells downregulated taurine-upregulated gene 1 (TUG1) expression and decreased viability in a dose-dependent manner. In addition, TUG1 knockdown (KD) increased HG-induced apoptosis, while TUG1 overexpression (OE) reduced HG-induced apoptosis in podocytes. HG-induced mitochondrial dysfunction was identified in podocytes, with increased reactive oxygen species levels, decreased complex I/III activity and decreased basal/maximal oxygen consumption rate. TUG1 KD worsened HG-induced mitochondrial dysfunction, and TUG1 OE reversed these effects. At the molecular level, TUG1 was revealed to promote sirtuin 1 (SIRT1) expression by sponging microRNA (miR)-9, and SIRT1 OE reversed the HG-induced apoptosis and mitochondrial dysfunction increased by TUG1 KD. The present data indicated that downregulation of TUG1 induced by HG was associated with HG-induced apoptosis and mitochondrial dysfunction in podocytes, and that TUG1 protected HG-induced podocytes by promoting SIRT1 expression via miR-9 inhibition.

Ginsenoside Rg3 alleviates septic liver injury by regulating the lncRNA TUG1/miR-200c-3p/SIRT1 axis

BackgroundStudies have shown that ginsenoside R3 (Rg3) plays a protective role in sepsis-induced organ injuries and mitochondrial dysfunction. Long noncoding RNA (lncRNA) taurine-upregulated gene 1 (TUG1) is regarded as a regulator in sepsis. However, the association between TUG1 and Rg3 remains elusive.MethodsA sepsis mouse model was established by caecal ligation and puncture (CLP), and liver injury was induced by haematoxylin-eosin (H&E) staining. Lipopolysaccharide (LPS) was used to induce hepatocyte damage. The expression levels of TUG1, microRNA (miR)-200a-3p, and silencing information regulator 1 (SIRT1) were examined by quantitative real-time polymerase chain reaction (qRT–PCR) assays. Cell viability was monitored using the Cell Counting Kit-8 (CCK-8) assay. MitoSOX Red staining and CBIC2 (JC-1) dye were employed to detect mitochondrial reactive oxygen species (ROS) and mitochondrial transmembrane potential (MTP) levels, respectively. The interaction between miR-200a-3p and TUG1 or SIRT1 was confirmed via dual-luciferase reporter or RNA immunoprecipitation (RIP) assay.ResultsRg3 upregulated TUG1 expression in liver tissues of CLP mice and LPS-induced hepatocytes. Rg3 could activate autophagy to improve mitochondrial dysfunction in LPS-treated hepatocytes, which was partially reversed by TUG1 depletion or miR-200a-3p overexpression. Importantly, TUG1 targeted miR-200a-3p to activate the SIRT1/AMP-activated protein kinase (AMPK) pathway in LPS-treated hepatocytes. Moreover, gain of TUG1 ameliorated mitochondrial dysfunction in LPS-treated hepatocytes by sequestering miR-200a-3p.ConclusionOur study revealed that Rg3 increased TUG1 expression and reduced miR-200a-3p expression to stimulate the SIRT1/AMPK pathway, thereby enhancing autophagy to improve sepsis-induced liver injury and mitochondrial dysfunction.

Long non-coding RNA TUG1 promotes proliferation and migration in PDGF-BB-stimulated HASMCs by regulating miR-216a-3p/SMURF2 axis

BackgroundAbnormal proliferation and migration of human airway smooth muscle cells (HASMCs) play an important role in the development of childhood asthma. Long non-coding RNAs (lncRNAs) have been demonstrated to participate in HASMC proliferation and migration. We aimed to explore more effects and molecular mechanism of taurine upregulated gene 1 (TUG1) in childhood asthma.ResultsTUG1 and SMURF2 were overexpressed and miR-216a-3p was downregulated in childhood asthma patients and PDGF-BB-stimulated HASMCs. TUG1 knockdown attenuated PDGF-BB-triggered proliferation and migration of HASMCs. MiR-216a-3p was targeted by TUG1, and miR-216a-3p suppression counteracted the repressive effects of TUG1 interference on proliferation and migration in PDGF-BB-treated HASMCs. SMURF2 was a downstream target of miR-216a-3p, and SMURF2 upregulation abated the inhibiting effects of miR-216a-3p on migration and proliferation in PDGF-BB-exposed HASMCs. TUG1 sponged miR-216a-3p to positively regulate SMURF2 expression.ConclusionTUG1 downregulation inhibited PDGF-BB-induced HASMC proliferation and migration by regulating miR-216a-3p/SMURF2 axis, offering novel insight into the potential application of TUG1 for childhood asthma treatment.

LncRNA TUG1 facilitates the development of endometrial cancer via interaction with FXR1

Purpose: To investigate the potential influence of long non-coding RNA (lncRNA) TUG1 on the development of endometrial cancer (EC).Methods: A total of 24 paired EC species and paracancerous species were collected, and the differential expressions of TUG1 in them were determined. The regulatory effects of TUG1 on proliferative and migratory potential in Ishikawa and HEC-1A cells were assessed using cell counting kit-8 (CCK-8) and Transwell assay, respectively. Potential protein binding TUG1 was predicted by bioinformatics analysis and subsequently verified using RIP (RNA-Binding Protein Immunoprecipitation) assay. Rescue experiments were conducted to uncover the mechanism of TUG1 in regulating the development of EC.Results: TUG1 was highly expressed in EC species and cell lines. Higher levels of TUG1 was observed in EC patients with metastases than those without metastatic cancer (p &lt; 0.05). Overexpression of TUG1 markedly facilitated proliferative and migratory potential in EC cells. Taurine-upregulated gene 1 (TUG1) directly bound Fragile X-related protein 1 (FXR1) and positively regulated its level (p &lt; 0.05). Through interaction with FXR1, TUG1 stimulated the malignant development of EC.Conclusion: LncRNA TUG1 is upregulated in EC species, which facilitates proliferative and migratory potentials in EC cells by interacting with FXR1.