Taurine Upregulated Gene 1 Expression Research Articles

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.

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.

Inhibition of Taurine-upregulated Gene 1 Upregulates MiR-34a-5p to Protect against Myocardial Ischemia/Reperfusion via Autophagy Regulation.

Taurine upregulated gene 1 (TUG1) has been identified on long noncoding RNA (lncRNA); however, its function in myocardial cells following ischemia/ reperfusion (I/R) injury has not been explored. This study aimed to investigate the role of LncTUG1 in I/R injury by focusing on its relationship with autophagy induction by regulating miR-34a-5p expression. We established a myocardial I/R model and H9C2 hypoxia-ischemic and reoxygenation (HI/R) conditions to induce I/R injury. TTC, Western blot, CCK-8 assay, quantitative reverse transcription PCR, flow cytometry, and confocal microscopy were used to assess the size of myocardial infarct, level of some apoptotic-related and autophagy-associated proteins, cell viability, the level of LncRNA TUG1, apoptosis, and autophagy, respectively. The results revealed that a TUG1 knockdown protected against I/R-induced myocardial injury by decreasing the impairment in cardiac function. LncRNA TUG1 expression was increased in a myocardial I/R model and HI/R in H9C2 cells. Moreover, inhibition of LncTUG1 enhanced H9C2 cell viability and protected the cells from HI/R-induced apoptosis. Silencing LncRNA TUG1 promoted HI/R-induced autophagy. Furthermore, TUG1 siRNA upregulated the level of miR-34a-5p compared to the HI/R group. The protective effect of LncRNA TUG1 inhibition on H9C2 cells following HI/R was eliminated by blocking autophagy with an miR-34a-5p inhibitor. These findings indicated that inhibiting TUG1 may reduce the extent of myocardial I/R injury by regulating miR-34a-5p. Taken together, these results suggest that LncRNA TUG1 may represent a novel therapeutic target for myocardial I/R injury.

Study of Long Non-Coding RNA Tug1 Expression in Egyptian Colorectal Adenocarcinoma Patients

Abstract Purpose Colorectal cancer (CRC) is one of the most fatal tumors worldwide. In Egypt, most CRC cases occur in individuals > 40 years old. TUG1 has been proved to be disrupted in different malignancies and may have a critical role in tumor progression, invasion, and metastasis. However, its role in CRC has not been adequately studied. Materials / Methods Quantitative real-time polymerase chain reaction (PCR) was used to evaluate the expression levels of long non-coding RNA (LncRNA) taurine upregulated gene 1 (TUG1), in nonmetastatic and metastatic CRC tissues and adjacent noncancerous tissues as control. Results LncRNA TUG1 expression was significantly upregulated in both nonmetastatic and metastatic CRC tissues, in comparison with the adjacent noncancerous tissue. It was found that TUG1 could have a possible prognostic role in CRC, by comparing the sensitivity and specificity of TUG1 with those of CEA and CA19–9. Conclusion The results of the current study suggest that the LncRNA TUG1 participates in the malignant behaviors of CRC cells.

TUG1 protects against ferroptosis of hepatic stellate cells by upregulating PDK4-mediated glycolysis

The induction of ferroptosis in hepatic stellate cells (HSCs) has shown promise in reversing liver fibrosis. And ferroptosis has been confirmed to be associated with glycolysis. The objective of this study is to determine whether ferroptosis inhibition in HSCs, induced by elevation of recombinant pyruvate dehydrogenase kinase isozyme 4 (PDK4)-mediated glycolysis, could mediate the pathogenesis of liver fibrosis. Liver fibrosis was induced using CCl4, the level of which was assessed through histochemical staining. Lentivirus was used to modulate the expression of specific genes. And underlying mechanisms were explored using primary HSCs extracted from normal mice. The results confirmed that Taurine up-regulated gene 1 (TUG1) expression was upregulated in liver fibrotic tissues and HSCs, showing a positive correlation with fibrosis. In addition, TUG1 attenuated ferroptosis in HSCs by promoting PDK4-mediated glycolysis, thereby promoting the progression of liver fibrosis. Moreover, TUG1 was observed to impact HSCs activation, exacerbating liver fibrosis to some extent. In conclusion, our study revealed that TUG1 expression was elevated in mouse models of liver fibrosis and activated HSCs, which inhibited ferroptosis in HSCs through PDK4-mediated glycolysis. This finding may open up a new therapeutic strategy for liver fibrosis.

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.

LncTUG1 ameliorates renal tubular fibrosis in experimental diabetic nephropathy through the miR-145-5p/dual-specificity phosphatase 6 axis

The renal interstitial fibrosis contributes to the progression and deterioration of diabetic nephropathy (DN). Long noncoding RNA taurine-up-regulated gene 1 (TUG1) in kidneys may be down-regulated by hyperglycemia. We aim to explore its role in tubular fibrosis caused by high glucose and the possible target genes of TUG1. In this study, a streptozocin-induced accelerated DN mouse model and a high glucose-stimulated HK-2 cells model was established to evaluate TUG1 expression. Potential targets of TUG1 were analyzed by online tools and confirmed by luciferase assay. A rescue experiment and gene silencing assay were used to investigate whether TUG1 plays its regulation role via miR-145-5p/dual-specificity phosphatase 6 (DUSP6) in HK2 cells. The effects of TUG1 on inflammation and fibrosis in high glucose treated tubular cells were evaluated by in vitro study, as well as in vivo DN mice model through AAV-TUG1 delivery. Results showed TUG1was downregulated in HK2 cells incubated with high glucose while miR-145-5p was upregulated. Overexpression of TUG1 alleviated renal injury by suppressing inflammation and fibrosis in vivo. Overexpression of TUG1 inhibited HK-2 cell fibrosis and relieved the inflammation. A mechanism study demonstrated that TUG1 directly sponged to miR-145-5p, and DUSP6 was identified as a target downstream of miR-145-5p. In addition, miR-145-5 overexpression and DUSP6 inhibition countervailed the impacts of TUG1. Our findings revealed that TUG1 overexpression alleviates kidney injury in DN mice and decreases the inflammatory response and fibrosis of high glucose-stimulated HK-2 cells via miR-145-5p/DUSP6 axis.

Long non-coding RNAs TUG1 and MEG3 in patients with type 2 diabetes and their association with endoplasmic reticulum stress markers.

Long non-coding RNAs (lncRNAs), including taurine upregulated gene 1 (TUG1), metastasis-associated lung adenocarcinoma transcript 1 (MALAT1), and maternally expressed 3 (MEG3) play a regulatory role in endoplasmic reticulum (ER) stress. The present study aimed to investigate the expression of these lncRNAs in patients with type 2 diabetes and their association with biochemical and ER stress parameters. Participants included 57 patients with diabetes and 32 healthy individuals. Real-time PCR was performed to assess MALAT1, TUG1, MEG3, ATF4, and CHOP gene expression in peripheral blood mononuclear cells. Plasma GRP78, advanced glycation end products (AGEs), and insulin were measured using enzyme-linked immunosorbent assay (ELISA), and insulin resistance (IR) was calculated by the homeostasis model assessment of insulin resistance (HOMA-IR). The expression of TUG1, MEG3, ATF4, and CHOP genes was significantly increased in the patients with diabetes compared to healthy individuals. MALAT1 gene expression was also higher in patients group; although it did not reach significant levels. TUG1 and MEG3 expression revealed significant positive correlations with the indices of glycemic control, including FBS, HbA1c, HOMA-IR, and AGEs, as well as markers of ER stress. MALAT1 expression was also positively correlated with ATF4 and AGEs. The expression levels of TUG1 and MEG3 lncRNAs were increased in patients with diabetes and were associated with glycemic control and components of ER stress. Thus, these lncRNAs might be considered appropriate markers to identify ER stress due to hyperglycemia.

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.

Aging-regulated TUG1 is dispensable for endothelial cell function.

The evolutionary conserved Taurine Upregulated Gene 1 (TUG1) is a ubiquitously expressed gene that is one of the highest expressed genes in human and rodent endothelial cells (ECs). We here show that TUG1 expression decreases significantly in aging mouse carotid artery ECs and human ECs in vitro, indicating a potential role in the aging endothelial vasculature system. We therefore investigated if, and how, TUG1 might function in aging ECs, but despite extensive phenotyping found no alterations in basal EC proliferation, apoptosis, barrier function, migration, mitochondrial function, or monocyte adhesion upon TUG1 silencing in vitro. TUG1 knockdown did slightly and significantly decrease cumulative sprout length upon vascular endothelial growth factor A stimulation in human umbilical vein endothelial cells (HUVECs), though TUG1-silenced HUVECs displayed no transcriptome-wide mRNA expression changes explaining this effect. Further, ectopic expression of the highly conserved and recently discovered 153 amino acid protein translated from certain TUG1 transcript isoforms did not alter angiogenic sprouting in vitro. Our data show that, despite a high expression and strong evolutionary conservation of both the TUG1 locus and the protein sequence it encodes, TUG1 does not seem to play a major role in basic endothelial cell function.

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.

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.

LncRNA TUG1 promotes the migration and invasion in type I endometrial carcinoma cells by regulating E–N cadherin switch

ObjectiveAccumulating evidence has demonstrated that lncRNA Taurine-upregulated gene 1 (TUG1) plays an important role in regulation of cell morphology, migration, proliferation and apoptosis. Our aim was to evaluate the oncogenic role of TUG1 in type I Endometrial Carcinoma (EC) and explore the precise mechanism of TUG1 involved in tumor progression. Materials and methodsThe GSE17025 data set was used to analyze the correlation of TUG1 expression with type I EC patients’ prognosis. Furthermore, TUG1 expression profiles were measured by qRT-PCR from carcinoma tissues and adjacent nonneoplastic tissues (NNT) of 105 type I EC patients. The regulation of epithelial–mesenchymal transition (EMT) related molecules, p-AKT and AKT by TUG1 knockdown was investigated using Western blot analysis; meanwhile, the oncogenic roles of TUG1 were evaluated using cell viability and transwell migration/invasion assay in Hec-1-A and Ishikawa cell lines. ResultsFirstly, we observed a significant association between higher TUG1 expression and lower survival rate in type I EC patients using the GSE17025 data set. A significant elevation of TUG1 levels was confirmed in type I EC tissues compared with NNT in the 105 type I EC patients, and high expression of TUG1 was associated with lymph vascular space invasion (LVSI) and lymph node metastasis (LNM). Subsequently, TUG1 knockdown could remarkably inhibit the Hec-1-A and Ishikawa cell invasion and migration in the functional experiment. Furthermore, our results showed that the protein levels of E-cadherin increased and N-cadherin decreased significantly, while β-catenin and Vimentin were not significantly altered upon TUG1 silencing in both Hec-1-A and Ishikawa cells. Finally, we found the p-AKT and AKT protein levels, and the rate of p-AKT/t-AKT has a tendency to be down-regulate in Hec-1-A cells, while the AKT pathway was not change significantly in Ishikawa cells after TUG1 knockdown. ConclusionCollectively, our data reveal that TUG1 might be regarded as an oncogenic molecule that promotes type I EC cells metastasis leading to tumor progression, at least partially, by regulating E–N cadherin switch and the AKT pathway.

LncRNA TUG1 regulates hyperuricemia-induced renal fibrosis in a rat model.

Renal fibrosis is most common among chronic kidney diseases. Molecular studies have shown that long noncoding RNAs (lncRNAs) and microRNAs (miRNAs) participate in renal fibrosis, while the roles of lncRNA taurine upregulated gene 1 (TUG1) and miR-140-3p in hyperuricemia-induced renal fibrosis remain less investigated. In this study, a rat hyperuricemia model is constructed by oral administration of adenine. TUG1, miR-140-3p, and cathepsin D (CtsD) expression levels in rat models are measured. After altering TUG1, miR-140-3p, or CtsD expression in modelled rats, biochemical indices, including uric acid (UA), serum creatine (SCr), blood urea nitrogen (BUN), and 24-h urine protein are detected, pathological changes in the renal tissues, and renal fibrosis are examined. In renal tissues from hyperuricemic rats, TUG1 and CtsD are upregulated, while miR-140-3p is downregulated. Inhibiting TUG1 or CtsD or upregulating miR-140-3p relieves renal fibrosis in hyperuricemic rats. Downregulated miR-140-3p reverses the therapeutic effect of TUG1 reduction, while overexpression of CtsD abolishes the role of miR-140-3p upregulation in renal fibrosis. Collectively, this study highlights that TUG1 inhibition upregulates miR-140-3p to ameliorate renal fibrosis in hyperuricemic rats by inhibiting CtsD.

Regulation of the TUG1/miR-145-5p/SOX2 axis on the migratory and invasive capabilities of melanoma cells.

Melanoma is the most prevalent malignancy of cutaneous carcinomas. Taurine-upregulated gene 1 (TUG1), a lncRNA, is a pivotal regulator of cutaneous malignancies. The present study aimed to investigate the impact and possible mechanisms of action of TUG1 behind the progression of melanomas. Reverse transcription-quantitative PCR was conducted to detect the expression levels of TUG1, microRNA (miR)-145-5p and SOX2 in melanoma tissues and cell lines. Cell Counting Kit-8 (CCK-8) assays were performed to measure the proliferative ability of melanoma cells and transwell assays were used to examine the migration and invasion of melanoma cells. Dual luciferase reporter and RNA immunoprecipitation (RIP) assays were utilized to identify the interactions among TUG1, miR-145-5p and SOX2. Western blotting and immunohistochemical assays were performed to determine the expression profile of SOX2. The impact of TUG1 on melanoma tumorigenesis was assessed using tumorigenicity assays. TUG1 expression levels were elevated in melanoma tumor tissues and cell lines. Reduced TUG1 expression levels significantly inhibited the proliferative, migratory and invasive abilities of melanoma cells. The expression levels of miR-145-5p were decreased in melanoma tumor tissues and cell lines. TUG1 directly targeted miR-145-5p and downregulated miR-145-5p. Upregulation of TUG1 counteracted the promotion of the proliferative, migratory and invasive abilities of melanoma cells induced by the overexpression of miR-145-5p. SOX2 was a target of miR-145-5p and its expression was negatively regulated by miR-145-5p, while positively regulated by TUG1. TUG1 regulated SOX2 expression through sponging miR-145-5p. Silencing of TUG1 also inhibited melanoma tumorigenesis in mice. In conclusion, the TUG1/miR-145-5p/SOX2 axis regulated the migration and invasion of melanoma cells.

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.

LncRNA TUG1 Promotes Apoptosis, Invasion, and Angiogenesis of Retinal Endothelial Cells in Retinopathy of Prematurity via MiR-145-5p.

PurposeRetinopathy of prematurity (ROP) is a common retinal vascular disease in premature neonates. In recent years, there is increasing evidence that the long non-coding RNA taurine upregulated gene 1 (TUG1) plays a regulatory role in vascular diseases, suggesting a potential role for TUG1 in vascular endothelial cells. We hypothesized that TUG1 may be associated with ROP. Our aim, therefore, was to explore the biological functions of TUG1 in aberrant retinal development.MethodsWe used the mouse oxygen-induced retinopathy (OIR) model to simulate the pathological changes of retinal in ROP. Quantitative real-time polymerase chain reaction was used to detect the expression of TUG1, miR-145-5p and cellular communication network factor 1 (CCN1). Human retinal endothelial cells (HRECs) were treated with CoCl2 to mimic hypoxia conditions. Cellular functional changes were observed after transfection with RNA interference (RNAi)-TUG1 and miR-145-5p mimics. The apoptosis of HRECs was detected by flow cytometry, the migration ability was detected by wound healing and transwell migration assays, and the ability of angiogenesis was detected by tube formation assay. The potential binding sites between TUG1, miR-145-5p, and CCN1 were verified by dual-luciferase reporter assays. The degree of retinopathy was evaluated by staining retinal sections with hematoxylin and eosin, and the expression of CCN1, HIF-1α, VEGF, caspase-3, Bcl-2, IL-1β, and TNF-α protein was analyzed by Western blotting and immunohistochemistry.ResultsIn the retina tissue of OIR mice, TUG1, miR-145-5p, and CCN1 were differentially expressed. Knocking down TUG1 attenuated apoptosis, migration, and angiogenesis induced by hypoxia on HRECs, as did miR-145-5p overexpression. Results from reporter assays indicate direct interactions between TUG1, miR-145-5p, and CCN1. Intravitreal injection of miR-145-5p mimics reduced the degree of retinopathy.ConclusionTUG1 acts as a molecular sponge of miR-145-5p to regulate CCN1 expression and thus regulate the development of retinal neovascularization. This regulatory mechanism may provide a new theoretical basis for the prevention and treatment of ROP.

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.

Role of lncRNA TUG1 in Adenomyosis and its Regulatory Mechanism in Endometrial Epithelial Cell Functions.

Adenomyosis (AM) is a common gynecological disorder that can cause pelvic pain. The regulatory role of long noncoding RNAs (lncRNAs) in AM progression has been widely reported. This study investigated the effect and mechanism of lncRNA taurine-upregulated gene 1 (TUG1) on endometrial epithelial cells (EECs) in AM. Endometrial tissues of AM patients and controls were collected. A murine model of AM was established by tamoxifen induction. TUG1 expression in endometrial tissues of AM patients and mice was determined. In vivo, the effect of TUG1 on AM mice was measured through H&E staining, Masson's staining, uterine weight, and estradiol concentration. EECs isolated from AM patients were transfected with sh-TUG1. In vitro, the effect of TUG1 on the proliferation, migration, invasion, epithelial-mesenchymal transition (EMT), and angiogenesis of EECs was evaluated by CCK8, colony formation, immunofluorescence, wound healing, and Transwell assays. The binding relationship among TUG1, E2F4, and KLF5 was confirmed using RNA immunoprecipitation and RNA pull-down assays. A function rescue experiment was designed to verify the effect of KLF5 on EECs. TUG1 expression was elevated in AM mice and patients. Downregulation of TUG1 promoted the recovery of AM mice. Downregulation of TUG1 suppressed proliferation, migration, invasion, EMT, and angiogenesis of EECs. Mechanically, TUG1 suppressed KLF5 transcription by binding to E2F4. Downregulation of KLF5 reversed the inhibitory effect of TUG1 silencing on the functions of EECs. TUG1 expression was elevated in AM, and TUG1 facilitated proliferation, migration, invasion, EMT, and angiogenesis of EECs via E2F4/KLF5, thereby aggravating AM.