Overexpression Of Taurine Upregulated Gene 1 Research Articles

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.

Taurine-Upregulated Gene 1 Attenuates Cerebral Angiogenesis following Ischemic Stroke in Rats.

Angiogenesis is one of the therapeutic targets of cerebral infarction. Long noncoding RNAs (lncRNAs) can regulate the pathological process of angiogenesis following ischemic stroke. Taurine-upregulated gene 1 (TUG1), an lncRNA, is correlated to ischemic stroke. We intended to determine the effect of TUG1 on angiogenesis following an ischemic stroke. Middle cerebral artery occlusion (MCAO) was adopted to build a focal ischemic model of the rat brain, and pcDNA-TUG1 and miR-26a mimics were injected into rats. Neurological function was estimated through modified neurological severity scores. The volume of focal brain infarction was calculated through 2,3,5-triphenyltetrazolium chloride staining. The level of TUG1 and miR-26a was measured by PCR. The expression of vascular endothelial growth factor (VEGF) and CD31 was checked using immunohistochemistry and western blot. The correlation between miR-26a and TUG1 was verified through a luciferase reporter assay. TUG1 increased noticeably while miR-26a was markedly reduced in MCAO rats. Overexpression of miR-26a improved neurological function recovery and enhanced cerebral angiogenesis in MCAO rats. TUG1 overexpression aggravated neurological deficits and suppressed cerebral angiogenesis in MCAO rats. Bioinformatics analysis revealed that miR-26a was one of the predicted targets of TUG1. Furthermore, TUG1 combined with miR-26a to regulate angiogenesis. TUG1 overexpression antagonized the role of miR-26a in neurological recovery and angiogenesis in MCAO rats. TUG1/miR-26a, which may act as a regulatory axis in angiogenesis following ischemic stroke, can be considered a potential target for cerebral infarction therapy.

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 protects intestinal epithelial cells from damage induced by high glucose and high fat via AMPK/SIRT1.

he incidence of obesity and type2 diabetes mellitus (T2DM) is increasing year by year and shows a trend towards younger age groups worldwide. It has become a disease that endangers the health of individuals all over the world. Among numerous weight loss surgeries, sleeve gastrectomy (SG) has become one of the most common surgical strategies for the treatment of T2DM. However, SG‑mediated alterations to the molecular mechanism of metabolism require further investigation. Thus, reverse transcription‑quantitative PCR was used to detect the expression levels of long non‑coding (lnc)RNA taurine‑upregulated gene1 (TUG1), Sirtuin1 (SIRT1), AMP‑activated protein kinase (AMPK) and uncoupling protein2 (UCP2) in the serum of T2DM patients, as well as in HIEC‑6 and SW480 cells following treatment with high glucose and high fat (HGHF). Protein expression was detected by western blotting. Cell Counting Kit‑8 assays were performed to analyze cell viability, and flow cytometry and a TUNEL assay was performed to evaluate cell apoptosis. The secretion of ILs in the culture medium was detected by conducting ELISAs. The results showed that lncRNA TUG1 and UCP2 expression was upregulated, SIRT1 and AMPK expression levels were decreased by SG. Under HGHF conditions, HIEC‑6 and SW480 cell viability was inhibited, apoptosis was promoted, TUG1 expression was downregulated, and SIRT1 and AMPK expression levels were upregulated. The secretory levels of IL‑1β, IL‑6 and IL‑8 were increased, whereas the secretion of IL‑10 was decreased under HGHF conditions. lncRNA TUG1 overexpression significantly reversed the effects of HGHF on cell viability, apoptosis and SIRT1, AMPK, UCP2 and Bcl‑2 expression levels. Together, the findings of the present study demonstrated that lncRNA TUG1 alleviated the damage induced by HGHF in intestinal epithelial cells by downregulating SIRT1 and AMPK expression, and upregulating UCP2 expression. Thus, the lncRNA TUG1/AMPK/SIRT1/UCP2 axis may serve an important role in the treatment of T2DM.

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.

Long noncoding TUG1 promotes angiogenesis of HUVECs in PE via regulating the miR-29a-3p/VEGFA and Ang2/Tie2 pathways.

Preeclampsia (PE) is a pregnancy-specific disease that is associated with oxidative stress-induced endothelial dysfunction. Long noncoding RNAs (lncRNAs) are related to PE progression. The purpose is to study whether lncRNA taurine-upregulated gene 1 (TUG1) takes part in endothelial dysfunction in PE. The placenta tissues were collected from PE patients and normal subjects. Human umbilical vein endothelial cells (HUVECs) were suffered from hypoxia-reoxygenation (H/R). TUG1, miR-29a-3p and vascular endothelial growth factor A (VEGFA) were detected via qRT-PCR. soluble fms-related tyrosine kinase-1 (sFLT1) and soluble endoglin (sENG) levels were detected by ELISA. Cell proliferation, migration, invasion and angiogenesis were examined via MTT, wound healing analysis, transwell and tube formation analysis. The proteins in VEGFA and angiopoietin 2 (Ang2)/tyrosine kinase with immunoglobulin-like and EGF-like domains 2 (Tie2) signaling were measured by western blot. The binding relationship was analyzed via Starbase, Jefferson and dual-luciferase reporter analysis. TUG1 and VEGFA levels were downregulated, and levels of miR-29a-3p, sFLT1 and sENG were increased in PE patients. TUG1 abundance was reduced in H/R-stimulated HUVECs, and TUG1 overexpression increased proliferation, migration, invasion and angiogenesis, and activated the VEGFA and Ang2/Tie2 signaling in H/R-stimulated HUVECs. TUG1 sponged miR-29a-3p, and miR-29a-3p overexpression reversed the function of TUG1 on H/R-induced HUVECs dysfunction. MiR-29a-3p knockdown attenuated H/R-induced inhibition of proliferation, migration, invasion, angiogenesis and activation of the VEGFA and Ang2/Tie2 signaling in HUVECs. VEGFA and Ang2 were targeted by miR-29a-3p, and VEGFA or Ang2 silence weakened the role of miR-29a-3p knockdown in H/R-caused HUVECs dysfunction. TUG1 facilitates proliferation, migration, invasion and angiogenesis in H/R-stimulated HUVECs via activating the VEGFA and Ang2/Tie2 signaling by regulating miR-29a-3p.

Long non-coding RNA TUG1 promotes the osteogenic differentiation of bone marrow mesenchymal stem cells by regulating the AMPK/mTOR/autophagy pathway.

Promoting the differentiation of bone marrow mesenchymal stem cells (BMSCs) into osteoblasts is an effective strategy against osteoporosis. Long non-coding RNAs are closely implicated in BMSC osteogenic differentiation. The present study explored the expression pattern and biological role of taurine upregulated gene 1 (TUG1) in osteogenic differentiation. The expressions of TUG1 and osteogenic markers following the osteogenic induction of BMSCs were detected. The functional relevance of TUG1 was evaluated by performing gain- and loss-of-function tests. Inhibitors of AMP-activated protein kinase (AMPK) autophagy were applied to ascertain the effects of TUG1 on the osteogenic differentiation of BMSCs. TUG1 expression increased during the osteogenic differentiation of BMSCs. The overexpression of TUG1 was promoted, whereas the knockdown of TUG1 was suppressed, by BMSC osteogenic differentiation. Mechanically, TUG1 promoted the osteogenesis of BMSCs via the AMPK-mammalian target of rapamycin (mTOR)-autophagy signaling pathway. Blocking AMPK and autophagy could abrogate the osteogenic role of TUG1 in BMSCs. These results demonstrated that TUG1 promoted the osteogenic differentiation of BMSCs by regulating the AMPK/mTOR/autophagy axis, suggesting that targeting TUG1 may be a potential therapy for osteoporosis.

LncRNA TUG1 promotes bladder cancer malignant behaviors by regulating the miR-320a/FOXQ1 axis

BackgroundGrowing evidence has showed long noncoding RNAs (lncRNAs) play critical roles in bladder cancer (BC) progression. LncRNA taurine upregulated gene 1 (TUG1) was involved in the development of human malignancies. However, the intrinsic and concrete molecular mechanisms of TUG1 in BC remain largely unknown. MethodsExpression patterns of TUG1, miR-320a and FOXQ1 in BC tissues and cell lines were measured using qRT-PCR and western blot, respectively. Cell proliferation was detected by CCK-8 and colony formation assays. The capacity of cell migration and invasion was evaluated using wound healing and transwell assay. Tumor xenograft assay was performed to further validate the role of TUG1 in BC progression. Dual luciferase reporter assay and FISH analysis were employed to verify the TUG1/miR-320a/FOXQ1 regulatory network. ResultsTUG1 was significantly higher expression in BC specimens and cell lines. TUG1 knockdown suppressed BC cells malignant behaviors in vitro and inhibited tumor growth and metastasis in vivo, while TUG1 overexpression promoted BC cells malignant behaviors in vitro. However, the function of miR-320a was opposite to that of TUG1, and miR-320a inhibitor partially eliminated the inhibitory effect of TUG1 knockdown on the malignant behavior of BC cells. As a microRNA sponge, TUG1 actively elevated FOXQ1 expression to sponge miR-320a and subsequently promoted BC cells malignant phenotypes. ConclusionTUG1 may have great potential as therapeutic target for BC, since TUG1 silencing inhibited cell proliferation, migration and invasion in BC, while promoted cell apoptosis, by regulating the miR-320a/FOXQ1 axis.

Long noncoding RNAs Colorectal Neoplasia Differentially Expressed and taurine-upregulated gene 1 are downregulated in sepsis and positively regulate each other to suppress the apoptosis of cardiomyocytes

ABSTRACT Long noncoding RNAs (lncRNAs) Colorectal Neoplasia Differentially Expressed (CRNDE) and taurine-upregulated gene 1 (TUG1) play similar roles in sepsis, indicating the existence of the crosstalk between them. Sepsis is a major cause of injuries in heart, which are related to high mortality rates. This study was therefore carried out to analyze the potential crosstalk between CRNDE and TUG1 in sepsis, with a focus on sepsis-induced cell apoptosis in heart. Expression of CRNDE and TUG1 was analyzed with RT-qPCR. Correlations between them were analyzed by Pearson’s correlation coefficient. CRNDE and TUG1 were overexpressed in cardiomyocytes to determine the relationship between them. The roles of CRNDE and TUG1 in regulating the apoptosis of cardiomyocytes were explored by cell apoptosis assay. We found that both CRNDE and TUG1 were downregulated in sepsis. In cardiomyocytes, LPS treatment resulted in the downregulation of CRNDE and TUG1. Overexpression of CRNDE and TUG1 in cardiomyocytes increased the expression levels of each other. Under lipopolysaccharide (LPS) treatment, decreased apoptosis rates of cardiomyocytes were observed after CRNDE and TUG1 overexpression. CRNDE and TUG1 co-overexpression showed a stronger effect. In conclusion, CRNDE and TUG1 are downregulated in sepsis and they positively regulate each other to suppress the apoptosis of cardiomyocytes.

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 < 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 < 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.

LncRNA-TUG1 promotes the progression of infantile hemangioma by regulating miR-137/IGFBP5 axis

BackgroundPrevious studies indicated that lncRNA taurine upregulated gene 1 (TUG1) played essential roles in human cancers. This study aimed to investigate its function in infantile hemangioma (IH).MethodsA total of 30 pairs of clinical infantile specimens were used in this study. The expression of TUG1 in IH tissues was assessed by quantitative reverse transcriptase PCR (qRT-PCR). Two short hairpin RNA targeting TUG1 (sh-TUG1-1 and sh-TUG1-2) were transfected into hemangioma-derived endothelial cells, HemECs, to block its expression. The effects of TUG1 on HemECs were evaluated by Cell Counting Kit-8 (CCK-8), colony formation assay, wound healing assay, and Transwell assay. The underlying molecular mechanism of TUG1 was investigated by Starbase prediction and luciferase reporter assay and further determined by loss- and gain-of-function approaches. In addition, the role of TUG1 on tumorigenesis of HemECs was confirmed in an in vivo mouse model.ResultsTUG1 was significantly upregulated in infant hemangioma tissues compared with normal adjacent subcutaneous tissues. The loss- and gain-of-function approaches indicated that TUG1 overexpression promoted proliferation, migration, and invasion of HemECs in vitro, and TUG1 knockdown inhibited the tumorigenesis of HemECs in vivo. Specifically, TUG1 could compete with IGFBP5 for miR137 binding. Rescue experiments further confirmed the role of the TUG1/miR137/IGFBP5 axis in HemECs.ConclusionTUG1 was closely associated with the progression of IH by regulating the miR-137/IGFBP5 axis, which might be a potential target for IH treatment.

Overexpression of lncRNA TUG1 Alleviates NLRP3 Inflammasome-Mediated Cardiomyocyte Pyroptosis Through Targeting the miR-186-5p/XIAP Axis in Coronary Microembolization-Induced Myocardial Damage.

Coronary microembolization (CME) is a complicated problem that commonly arises in the context of coronary angioplasty. The lncRNA taurine-up regulated gene 1 (TUG1), significantly contributes to cardiovascular diseases; however, its contribution to CME-induced myocardial damage remains elusive. Herein, we establish the rat CME model and investigate the role of TUG1 in CME. The cell viability was evaluated via CCK-8 assay. Serum and cell culture supernatant samples were evaluated via ELISA. The dual luciferase reporter (DLR) assay, RIP, and RNA-pull down were conducted to validate the associations between TUG1 and miR-186-5p as well as miR-186-5p and XIAP. The expression of TUG1, miR-186-5p, and XIAP mRNA were determined by RT-qPCR, and proteins were evaluated via immuneblotting. As a result, TUG1 and XIAP were significantly down-regulated, and the miR-186-5p level was found to be remarkably up-regulated in CME myocardial tissues. Overexpression of TUG1 alleviated CME-induced myocardial injury and pyroptosis, whereas TUG1 knockdown showed the opposite effects. The DLR assay, RIP, and RNA-pull down results reveal that TUG1 directly targets miR-186-5p and miR-186-5p directly targets XIAP. In vitro rescue experiments show that TUG1 overexpression alleviates LPS-caused cardiomyocyte injury and pyroptosis via sponging miR-186-5p and regulating XIAP, and depression of miR-186-5p reduces LPS-induced cardiomyocyte injury and pyroptosis by targeting XIAP. Concludingly, the overexpression of TUG1 alleviates NLRP3 inflammasome-mediated cardiomyocyte pyroptosis through targeting the miR-186-5p/XIAP axis in CME-induced myocardial injury.

LncRNA TUG1 ameliorates diabetic nephropathy via inhibition of PU.1/RTN1 signaling pathway.

Diabetic nephropathy (DN) is a leading cause of end-stage renal failure. The study aimed to investigate whether long noncoding RNA taurine-upregulated gene 1 (TUG1) can ameliorate the endoplasmic reticulum stress (ERS) and apoptosis of renal tubular epithelial cells in DN, and the underlying mechanism. The DN mouse model was established by streptozocin injection, and the human renal tubular epithelial cell line HK-2 was treated with high glucose (HG) to mimic DN in vitro. The molecular mechanism was explored through dual-luciferase activity assay, RNA pull-down assay, RNA immunoprecipitation (RIP), and chromatin immunoprecipitation (CHIP) assay. The expression of TUG1 was significantly decreased in the renal tubules of DN model mice. Overexpression of TUG1 reduced the levels of ERS markers and apoptosis markers by inhibiting reticulon-1 (RTN1) expression in HG-induced HK-2 cells. Furthermore, TUG1 down-regulated RTN1 expression by inhibiting the binding of transcription factor PU.1 to the RTN1 promoter, thereby reducing the levels of ERS markers and apoptosis markers. Meanwhile, TUG1-overexpression adenovirus plasmids injection significantly alleviated tubular lesions, and reduced RTN1 expression, ERS markers and apoptosis markers, whereas these results were reversed by injection of PU.1-overexpression adenovirus plasmids. TUG1 restrains the ERS and apoptosis of renal tubular epithelial cells and ameliorates DN through inhibition of transcription factor PU.1.

LncRNA TUG1 inhibits the cancer stem cell‑like properties of temozolomide‑resistant glioma cells by interacting with EZH2.

Temozolomide (TMZ) is currently one of the first-line drugs used for the treatment of high-grade gliomas. However, TMZ resistance results in unsatisfactory therapeutic effects in gliomas. Cancer stem cells (CSCs) have recently been determined to serve a pivotal regulatory role in tumor metastasis, recurrence and chemoresistance. In addition, numerous reports have shown that long non-coding RNAs (lncRNAs) exert an essential role in the occurrence and development of tumors, and can be used as biomarkers for tumor diagnosis and treatment. Among them, studies have revealed that taurine upregulated gene 1 (TUG1) exhibits an important regulatory effect on the malignant biological behavior of glioma cells. Moreover, it has been reported that enhancer of Zeste homolog 2 polycomb repressive complex subunit 2 (EZH2) promotes tumorigenesis, including in glioma. However, the underlying mechanism of the interaction of TUG1 and EZH2 with CSCs of glioma remains elusive, and thus requires further clarification. The present study aimed to explore the role of TUG1 and EZH2 in TMZ resistance in glioma. Cell Counting Kit-8, colony formation,sphere formation and Annexin V-FITC/PI assays were used to detect the proliferation, clone formation efficiency, stemness and apoptosis of TMZ-resistant glioma cells. Xenograft tumor assay was used to detect the effect of TUG1 on the tumorigenesis of TMZ-resistant glioma cells. The present findings demonstrated that TUG1 exhibited a low expression in glioma cells, while EZH2 expression was the opposite. Moreover, it was observed that A172/TMZ cells possessed higher CSCs-like properties compared with parent cells, and that TUG1 and EZH2 were abnormally expressed in A172/TMZ cells. Knockdown of TUG1 or overexpression of EZH2 promoted A172/TMZ cell proliferation and CSCs-like properties, as well as inhibited their apoptosis, thereby enhancing the TMZ resistance of A172/TMZ cells. Furthermore, it was found that TUG1 alleviated the TMZ resistance of A172/TMZ cells by inhibiting EZH2 expression. Of note, overexpression of TUG1 inhibited the tumorigenicity of A172/TMZ cells by downregulating EZH2 expression in vivo. Collectively, the present study demonstrated that TUG1 served an essential regulatory role in TMZ resistance of gliomas.

LncRNA Taurine Upregulated Gene 1 as a Potential Biomarker in the Clinicopathology and Prognosis of Multiple Malignant Tumors: A Meta-Analysis

Background The lncRNA taurine upregulated gene 1 (TUG1) is a recently identified potential biomarker in cancer. However, its prognostic role in various cancers is inconsistent among published data. We conducted this meta-analysis to comprehensively confirm the prognostic effect of TUG1 in malignant tumors. Methods We systemically analyzed the prognostic-predictive capacity of TUG1 through amplifying sample sizes and cancer types. STATA 12.0 was applied for this meta-analysis. Results A total of 57 eligible studies were included in our meta-analysis. The pooled results suggested that overexpression of TUG1 was significantly correlated with unfavorable overall survival (OS) (HR = 1.70, p < 0.001), shorter recurrence-free survival (RFS) (HR = 2.40, p ≤ 0.001), and shorter event-free survival (EFS) (HR = 1.88, p < 0.001) in patients with cancer. In the subgroup analysis by cancer type, elevated TUG1 expression was associated with poorer survival in patients with gastrointestinal cancer, urinary tumors, gynecological tumors, hematological tumors, and osteosarcoma. However, high expression of TUG1 in respiratory tumors indicated a better prognosis. There was no correlation between high TUG1 expression and OS in patients with head and neck neoplasms or melanoma. Additionally, overexpression of TUG1 was found to be correlated with low-grade tumor differentiation, advanced tumor stage, positive lymphatic metastasis, and positive distant metastasis. Conclusions High TUG1 expression correlates with poor prognosis and advanced clinicopathological features, verifying the prognostic-predictive capacity of TUG1 in tumors, especially in gastrointestinal cancer, urinary tumors, gynecological tumors, hematological tumors, and osteosarcoma. Meanwhile, the prognostic role of TUG1 in respiratory tumor may be opposite to other tumors.

Knockdown of lncRNA TUG1 inhibits hippocampal neuronal apoptosis and participates in aerobic exercise-alleviated vascular cognitive impairment

ObjectivesOur previous study indicated that aerobic exercise relieves cognitive impairment in patients with vascular cognitive impairment (VCI) via regulating brain-derived neurotrophic factor (BDNF), but the mechanism is not yet clear. This study aimed to explore whether lncRNA taurine upregulated gene 1 (TUG1) participates in the process of VCI by regulating BDNF.MethodsThe expressions of TUG1 and BDNF in the serum of VCI patients were detected. The potential molecular mechanisms of TUG1 in regulating hippocampal neuronal apoptosis were explored in oxygen and glucose deprivation-induced (OGD-induced) hippocampal cell line HT22. The VCI mouse model was established, and TUG1 and BDNF were overexpressed via lentivirus injection. The cognitive impairment of mice was detected by the Morris water maze experiment after the aerobic exercise.ResultsThe level of TUG1 was elevated in the serum of VCI patients compared with the control group. The knockdown of TUG1 in OGD-induced HT22 cells increased BDNF level and decreased cell apoptosis, and the downregulation of BDNF restored the decreased cell apoptosis. RNA immunoprecipitation and RNA pull-down assays showed that TUG1 could bind to BDNF protein. The aerobic exercise alleviated cognitive impairment and inhibited hippocampal apoptosis in VCI mice. Meanwhile, the overexpression of TUG1 reversed the therapeutic effects of aerobic exercise on cognitive impairment.ConclusionsThe knockdown of TUG1 reduced hippocampal neuronal apoptosis and participates in the aerobic exercise-alleviated VCI, which was partly through regulating BDNF.

TUG1 enhances high glucose-impaired endothelial progenitor cell function via miR-29c-3p/PDGF-BB/Wnt signaling

BackgroundDiabetes is associated with the dysfunction of endothelial progenitor cells (EPCs), characterized as impaired angiogenesis, a phenomenon thought to be involved in the development of diabetic foot. lncRNA plays an essential role in microvascular dysfunction and signaling pathways in patients with diabetes. lncRNA taurine upregulated gene 1 (TUG1) participates in angiogenesis in various cells. However, the mechanisms of TUG1 activity in EPCs have not been elucidated.MethodsWe isolated and then characterized EPCs from the peripheral blood of mice using immunofluorescence and flow cytometry. Western blot detected the wnt/β-catenin pathway in high glucose-treated EPCs. Bioinformatics analysis predicted a putative binding site for TUG1 on miR-29c-3p. The interactions among TUG1, platelet-derived growth factor-BB (PDGF-BB), and miR-29c-3p were analyzed by luciferase assays. In vivo, diabetic mouse ischemic limb was treated with normal saline or TUG1 overexpression lentiviruses.ResultsWe found that EPC migration, invasion, and tube formation declined after treatment with high glucose, but improved with TUG1 overexpression. Mechanically, wnt/β-catenin pathway and autophagy were involved in the function of TUG1 overexpression in high glucose-treated EPCs. Moreover, TUG1 regulates the PDGF-BB/wnt pathway and function of high glucose-treated EPCs via miR-29c-3p. In vivo, injection of TUG1 lentivirus in a diabetic mouse ischemic limb model stimulated angiogenesis.ConclusionsOur findings suggest that TUG1 restores high glucose-treated EPC function by regulating miR-29c-3p/PDGF-BB/Wnt signaling.

LncRNA TUG1 reduces inflammation and enhances insulin sensitivity in white adipose tissue by regulating miR-204/SIRT1 axis in obesity mice.

Prevalence of obesity becomes an important health issue worldwide, but the management of obesity remains unsatisfied. This study aimed to explore the mechanism of long non-coding RNA TUG/miR-204/SIRT1 axis, which was involved in the pathogenesis of obesity. Obesity mouse model was induced by high-fat diet and treated with taurine upregulated gene1 (TUG1) virus via tail intravenous injection. Then, body weight, serum glucose, insulin tolerance, testicular fat weight were detected, as well as the expression of TUG1, microRNA-204 (miR-204), sirtuin1 (SIRT1), and inflammation and fatty accumulation associated proteins and cytokines. Regulatory relationship between TUG1/SIRT1 and miR-204 was confirmed by dual-luciferase reporter activity assay. A high-glucose-induced 3T3-L1 cell model was also constructed to explore the regulatory mechanism of TUG/miR-204/SIRT1 axis in the pathogenesis of obesity at cell level after altering the expression of TUG1, miR-204, and SIRT1. Overexpression of TUG1 could significantly attenuate the weight, serum glucose, glucose, insulin tolerance, fatty accumulation, and inflammation in obesity mice, as well as the elevation of miR-204, but increase the expression of SIRT1, phosphorylated AKT (p-AKT), glucose transporter4 (GLUT4), and peroxisome proliferator activated receptorγ (PPARγ). Both TUG1 and SIRT1 were targets of miR-204 and could be negatively regulated by miR-204. Overexpression of TUG1 could suppress the inflammation in adipocytes via downregulating miR-204 and promote GLUT4/PPARγ/AKT pathway high-glucose-induced inflammation in 3T3-L1 cells. miR-204 inhibitors could also suppress high-glucose-induced inflammation in 3T3-L1 cells via promoting SIRT1/ GLUT4/PPARγ/AKT pathway. LncRNA TUG1 could negatively regulate miR-204 to alleviate inflammation and insulin tolerance via promoting SIRT1/GLUT4/PPARγ/AKT pathway.

TUG1 Represses Apoptosis, Autophagy, and Inflammatory Response by Regulating miR-27a-3p/SLIT2 in Lipopolysaccharide-Treated Vascular Endothelial Cells

BackgroundThe dysfunction of vascular endothelial cells is associated with sepsis development. Long noncoding RNAs take part in the regulation of vascular endothelial cell function. This study aimed to explore the role and mechanism of long noncoding RNA taurine-upregulated gene 1 (TUG1) in lipopolysaccharide (LPS)-induced endothelial cell injury. MethodsLPS-treated human umbilical vein endothelial cells (HUVECs) were used as a model of sepsis in vitro. Quantitative real-time polymerase chain reaction was performed to detect the expression of TUG1, microRNA-27a-3p (miR-27a-3p) and slit guidance ligand 2 (SLIT2) messenger RNA. Western blot was conducted to measure the protein levels of SLIT2 as well as those involved in apoptosis, autophagy, and inflammatory response. Flow cytometry was used to detect cell apoptotic rate. The targets of TUG1 and miR-27a-3p were predicted via starBase (http://starbase.sysu.edu.cn/index.php). Dual-luciferase reporter, RNA immunoprecipitation, and pull-down assays were carried out to validate the target correlation between miR-27a-3p and TUG1/SLIT2. ResultsTUG1 expression was decreased after the treatment of LPS in HUVECs. Overexpression of TUG1 decreased LPS-induced apoptosis, autophagy, and inflammatory response. TUG1 was a sponge of miR-27a-3p. Upregulation of miR-27a-3p reversed the suppressive effect of TUG1 overexpression on LPS-induced apoptosis, autophagy, and inflammatory response. SLIT2 was a target of miR-27a-3p. Knockdown of miR-27a-3p could inhibit LPS-induced injury by increasing SLIT2 in HUVECs. TUG1 could enhance SLIT2 expression by competitively sponging miR-27a-3p. ConclusionsTUG1 could repress cell apoptosis, autophagy, and inflammatory response in LPS-treated HUVECs by sponging miR-27a-3p to target SLIT2, providing a potential target for the treatment of sepsis.

TUG1 knockdown inhibits the tumorigenesis and progression of prostate cancer by regulating microRNA-496/Wnt/β-catenin pathway.

Our study aimed to further investigate the roles and molecular mechanisms of lncRNA taurine upregulated gene 1 (TUG1) in the development and progression of PC. RT-qPCR assay was carried out to measure expression of TUG1, miR-496, together with β-catenin, cyclin D1 and c-myc. Protein levels of β-catenin, cyclin D1 and c-myc were detected by western blot assay. Cell proliferative ability was assessed by colony formation assay and CCK-8 assay. Cell migratory and invasive capacities were evaluated by Transwell migration and invasion assay. The interaction between miR-496 and TUG1 was explored by bioinformatics analysis, luciferase reporter assay and RNA immunoprecipitation assay. Mouse xenograft experiments were performed to further investigate the roles and molecular basis of TUG1 in the tumorigenesis of PC in vivo. TUG1 was highly expressed in PC tissues and cells (DU145 and PC3). TUG1 knockdown inhibited proliferation, migration and invasion in DU145 and PC3 cells. Moreover, TUG1 suppressed miR-496 expression by direct interaction. TUG1 overexpression abrogated miR-96-mediated antiproliferation, anti-migration and anti-invasion effects in DU145 and PC3 cells. TUG1 knockdown inactivated Wnt/β-catenin signaling pathway by upregulating miR-496 in DU145 and PC3 cells. Additionally, TUG1 knockdown inhibited DU145 cells derived PC xenograft growth by upregulating miR-496 and inactivating Wnt/β-catenin signaling in vivo. TUG1 knockdown suppressed PC cell proliferation, migration and invasion in vitro and curbed PC xenograft growth in vivo by regulating miR-496/Wnt/ β-catenin signaling pathway, deepening our understanding on etiology of PC.