LncRNA DANCR promotes macrophage lipid accumulation through modulation of membrane cholesterol transporters.

The progression of atherosclerosis (AS), the pathological foundation of coronary artery disease (CAD), is featured by massive lipid deposition in the vessel wall. LncRNAs are implicated in lipid disorder and AS, whereas the specific role of lncRNA DANCR in atherogenesis remains unknown. Here, we demonstrated that DANCR promotes macrophage lipid accumulation by regulating the expression of membrane cholesterol transport proteins. qPCR showed that compared to control groups, CAD patients and atherosclerotic mice had higher DANCR levels. Treating human THP-1 macrophages and mouse RAW264.7 macrophages with ox-LDL significantly upregulated the expression levels of DANCR. Oil Red O staining showed that the silence of DANCR robustly reduced, while overexpression of DANCR significantly increased the numbers and size of lipid droplets in ox-LDL-treated THP-1 macrophages. In contrast, the opposite phenomena were observed in DANCR overexpressing cells. The expression of ABCA1, ABCG1, SR-BI, and NBD-cholesterol efflux was increased obviously by DANCR inhibition and decreased by DANCR overexpression, respectively. Furthermore, transfection with DANCR siRNA induced a robust decrease in the levels of CD36, SR-A, and Dil-ox-LDL uptake, while DANCR overexpression amplified the expression of CD36, SR-A and the uptake of Dil-ox-LDL in lipid-laden macrophages. Lastly, we found that the effects of DANCR on macrophage lipid accumulation and the expression of membrane cholesterol transport proteins were not likely related to miR-33a. The present study unraveled the adverse role of DANCR in foam cell formation and its relationship with cholesterol transport proteins. However, the competing endogenous RNA network underlying these phenomena warrants further exploration.

HOXB2 promotes cisplatin resistance by upregulating lncRNA DANCR in ovarian cancer.

Ovarian cancer (OV) is a highly fatal malignant disease that commonly manifests at an advanced stage. Drug resistance, particularly platinum resistance, is a leading cause of treatment failure because first-line systemic chemotherapy primarily relies on platinum-based regimens. By analyzing the gene expression levels in the Cancer Genome Atlas database, Genotype-Tissue Expression database, and Gene Expression Omnibus datasets, we discerned that HOXB2 was highly expressed in OV and was associated with poor prognosis and cisplatin resistance. Immunohistochemistry and loss-of-function experiments on HOXB2 were conducted to explore its role in OV. We observed that suppressing HOXB2 could impair the growth and cisplatin resistance of OV in vivo and in vitro. Mechanical investigation and experimental validation based on RNA-Seq revealed that HOXB2 regulated ATP-binding cassette transporter members and the ERK signaling pathway. We further demonstrated that HOXB2 modulated the expression of long non-coding RNA DANCR, a differentiation antagonizing non-protein coding RNA, and thus influenced its downstream effectors ABCA1, ABCG1, and ERK signaling to boost drug resistance and cancer proliferation. These results verified that high expression of HOXB2 correlated with platinum resistance and poor prognosis of OV. Therefore, targeting HOXB2 may be a promising strategy for OV therapy.

Activation of lncRNA DANCR by H3K27 acetylation regulates proliferation of colorectal cancer cells.

The long noncoding DANCR functions as a tumor oncogene in many cancers, including colorectal cancer (CRC). However, the molecular mechanism of DANCR in CRC has not been explored. This study probed the function and potential mechanism by which DANCR contributes to the progression of CRC. The obtained data indicated that DANCR is overexpressed in CRC tissues and cell lines. Knockdown of DANCR hindered CRC cell proliferation, which was mediated by cyclin D1 and CDK4. Bioinformatic analysis, luciferase reporter assays and subcellular fractionation verified that DANCR directly binds to miR-508-5p. Moreover, DANCR acts as a miR-508-5p ceRNA to regulate expression of ATF1. In addition, upregulation of DANCR is attributed to H3K27 acetylation at the promoter region. In conclusion, our study confirmed that activation of lncRNA DANCR by H3K27 acetylation has an oncogenic role in CRC progression and provides a potential therapeutic target for CRC.

New evidence for a role of DANCR in cancers: a comprehensive review.

Cancer remains a leading cause of mortality and poses a substantial threat to public health. Studies have revealed that Long noncoding RNA DANCR is a cytoplasmic lncRNA whose aberrant expression plays a pivotal role in various cancer types. Within tumour biology, DANCR exerts regulatory control over crucial processes such as proliferation, invasion, metastasis, angiogenesis, inflammatory responses, cellular energy metabolism reprogramming, and apoptosis. By acting as a competitive endogenous RNA for miRNAs and by interacting with proteins and mRNAs at the molecular level, DANCR contributes significantly to cancer progression. Elevated DANCR levels have also been linked to heightened resistance to anticancer drugs. Moreover, the detection of circulating DANCR holds promise as a valuable biomarker for aiding in the clinical differentiation of different cancer types. This article offers a comprehensive review and elucidation of the primary functions and molecular mechanisms through which DANCR influences tumours.

DANCR maintained colon epithelial homeostasis by regulating the TNFα/NF-κB pathway.

Epithelial homeostasis is fundamental for the physiological functions of colon tissue. Dysregulation of colon epithelial structure leads to abnormal immune responses and diseases such as inflammatory bowel disease. In this work we found long non-coding RNA DANCR was a novel regulator to colon epithelial homeostasis. Silencing DANCR resulted in decreased expression of epithelial barrier proteins and enhanced susceptibility to TNFα stimulation, which was accompanied by hyperactivation of the NF-κB pathway. Mechanistical studies revealed DANCR modulated the expression of a protein methyltransferase SET7 to suppress responses to TNFα, as well as the activity of NF-κB pathway. In summary, DANCR regulated colon epithelial homeostasis through modulating the TNFα/NF-κB axis. These findings cast light on the discovery of novel regulators to colon epithelial homeostasis and added new evidence to the physiological functions of DANCR.

Depression of LncRNA DANCR alleviates tubular injury in diabetic nephropathy by regulating KLF5 through sponge miR-214-5p.

OBJECTIVE: Diabetic nephropathy (DN) manifests a critical aspect in the form of renal tubular injury. The current research aimed to determine the function and mechanism of long non-coding ribonucleic acid (LncRNA) differentiation antagonising non-protein coding RNA (DANCR), with a focus on its impact on renal tubular injury. METHODS: Quantitative reverse transcription polymerase chain reaction was employed to analyze the RNA levels of DANCR in the serum of patients with DN or human proximal tubular epithelial cells (human kidney 2 [HK2]). The diagnostic significance of DANCR was assessed using a receiver operating characteristic curve. A DN model was established by inducing HK-2 cells with high glucose (HG). Cell proliferation, apoptosis, and the levels of inflammatory factors, reactive oxygen species (ROS), and malondialdehyde (MDA) were detected using the Cell Counting Kit - 8, flow cytometry, and enzyme-linked immunosorbent assay. The interaction between microRNA (miR)-214-5p and DANCR or Krüppel-like factor 5 (KLF5) was investigated using RNA immunoprecipitation and dual-luciferase reporter assays. RESULTS: Elevated levels of DANCR were observed in the serum of patients with DN and HG-inducted HK-2 cells (P < 0.05). DANCR levels effectively identified patients with DN from patients with type 2 diabetes mellitus. Silencing of DANCR protected against HG-induced tubular injury by restoring cell proliferation, inhibiting apoptosis, and reducing the secretion of inflammatory factors and oxidative stress production (P < 0.05). DANCR functions as a sponge for miR-214-5p, and the mitigation of DANCR silencing on HG-induced renal tubular injury was partially attenuated with reduced miR-214-5p (P < 0.05). Additionally, KLF5 was identified as the target of miR-214-5p. CONCLUSION: DANCR was identified as diagnostic potential for DN and the alleviation of renal tubular injury via the miR-214-5p/KLF5 axis, following DANCR silencing, introduces a novel perspective and approach to mitigating DN.

Long non-coding RNA DANCR increases spinal cord neuron apoptosis and inflammation of spinal cord injury by mediating the microRNA-146a-5p/MAPK6 axis.

OBJECTIVE: This research was to unravel the impact of the lncRNA differentiation antagonizing non-protein coding RNA (DANCR)/microRNA (miR)-146a-5p/mitogen-activated protein kinase 6 (MAPK6) axis on spinal cord injury (SCI). METHODS: SCI mouse models were established and injected with si-DANCR or miR-146a-5p agomir. The recovery of motor function was assessed by Basso Mouse Scale. SCI was pathologically evaluated, and serum inflammatory factors were measured in SCI mice. Mouse spinal cord neurons were injured by H2O2 and transfected, followed by assessment of proliferation and apoptosis. DANCR, miR-146a-5p, and MAPK6 in tissues and cells were detected, as well as their relationship. RESULTS: DANCR increased and miR-146a-5p decreased in SCI. Silencing DANCR or enhancing miR-146a-5p stimulated the proliferation of mouse spinal cord neurons and reduced apoptosis. DANCR was bound to miR-146a-5p to target MAPK6. DANCR affected the proliferation and apoptosis of spinal cord neurons by mediating the miR-146a-5p/MAPK6 axis. Downregulating DANCR or upregulating miR-146a-5p improved inflammation, the destruction of spinal cord tissue structure, and apoptosis in SCI mice. CONCLUSION: DANCR affects spinal cord neuron apoptosis and inflammation of SCI by mediating the miR-146a-5p/MAPK6 axis.

Exploring the effect of LncRNA DANCR to regulate the Keap1-Nrf2/ARE pathway on oxidative stress in rheumatoid arthritis.

INTRODUCTION: Aberrant expression of long noncoding RNAs (LncRNAs) can regulate oxidative stress in rheumatoid arthritis (RA). This study focused on investigating the effects of LncRNA differentiation antagonizing nonprotein coding RNA (DANCR) regulation of Keap1-Nrf2/ARE pathway on inflammation and oxidative stress in RA. METHODS: The levels of LncRNA DANCR/miR-486-3p/Keap1 in peripheral blood of 30 RA groups and 30 normal subjects were examined, and the association of LncRNA DANCR with inflammatory indicators of RA was investigated. We stimulated fibroblast-like synoviocytes (FLS) from RA patients with tumor necrosis factor α and subsequently performed in vitro cellular assays to construct overexpression plasmids and small interfering RNAs of LncRNA DANCR to investigate the relationship between LncRNA DANCR and FLSs viability and migration in RA, as well as the effects on cellular oxidative stress factors and Keap1-Nrf2/ARE pathway; molecular biology analysis was used to predict microRNAs that can bind LncRNA DANCR, and luciferase verified the binding sites of LncRNA DANCR with Keap1 and miR-486-3p; to further refine the gene and protein expression results, we used reverse transcription-quantitative polymerase chain reaction and immunoblotting assays. RESULTS: In both groups of peripheral blood mononuclear cells, the expression levels of LncRNA DANCR and Keap1 messenger RNA were higher in the RA group than in the normal control group, and the opposite was true for miR-486-3p; LncRNA DANCR was positively correlated with total antioxidant capacity (TAOC), IL6, IL17, malondialdehyde (MDA), but not with IL11, rheumatoid factor, cyclic citrullinated peptide, superoxide dismutase (SOD), with 28-joint disease activity score, reactive oxygen species, C-reactive protein, and erythrocyte sedimentation rate were negatively correlated; overexpression of LncRNA DANCR stimulated the Keap1-Nrf2/ARE pathway, decreased the expression of IL10, SOD, TAOC, and increased the expression levels of MDA, IL11, IL-17, PD-L1, and silencing of LncRNA DANCR was the opposite, but knockdown of miR-486-3p or overexpression of keap1 reversed the expression of the above-mentioned inflammatory and oxidative factors. In addition, pcDNA-DANCR clearly showed stronger cell invasion and migration ability and exacerbated its inflammatory response, which may be related to the regulatory role of miR-486-3p and Keap1-Nrf2/ARE signaling pathway, and we verified their targeting relationship using dual luciferase, showing that DANCR could regulate Keap1-Nrf2/ARE through miR-486-3p modulates the Keap1-Nrf2/ARE pathway and affects inflammatory and oxidative responses in RA patients. CONCLUSION: The low-expressed LncRNA DANCR may regulate the Keap1-Nrf2/ARE pathway and suppress the inflammatory and oxidative responses in RA patients.

Dancr-BRG1 regulates Nfatc1 transcription and Pgc1ß-dependent metabolic shifts in osteoclastogenesis.

Long non-coding RNA (lncRNA) serves as a vital regulator of bone metabolism, but its role in pathologically overactive osteoclast differentiation remains elusive. Here, we identify lncRNA Dancr (Differentiation Antagonizing Non-protein Coding RNA) as a critical suppressor of osteoclastogenesis and bone resorption, which is down-regulated in response to estrogen deficiency. Global or osteoclast-specific Dancr Knockout mice display significant trabecular bone deterioration and enhanced osteoclast activity, but minimal alteration of bone formation. Moreover, the bone-targeted delivery of Dancr by Adeno-associated viral remarkably attenuates ovariectomy-induced osteopenia in mice. Mechanistically, Dancr establishes a direct interaction with Brahma-related gene 1 to prevent its binding and preserve H3K27me3 enrichment at the nuclear factor of activated T cells 1 and proliferator-activated receptor gamma coactivator 1-beta promoters, thereby maintaining appropriate expression of osteoclastic genes and metabolic programs during osteoclastogenesis. These results demonstrate that Dancr is a key molecule maintaining proper osteoclast differentiation and bone homeostasis under physiological conditions, and Dancr overexpression constitutes a potential strategy for treating osteoporosis.

DANCR Regulates hESC Differentiation Towards Definitive Endoderm / 中山大学学报(医学科学版)

ObjectiveTo explore the function of DANCR during the differentiation of human embryonic stem cells （hESC） toward definitive endoderm （DE）. MethodsThe in vitro DE differentiation system was established and its efficiency was verified. The correlation between the expression level of DANCR and DE differentiation process was detected. Using lentivirus system， we stably knocked down DANCR in hESC. The shDANCR hESC line was applied to DE differentiation， using qPCR and Western blot to detect the expression of DE marker genes SOX17 and FOXA2， and that of primitive streak marker genes Brachyury （T）， EOMES， MIXL1 and GSC. Dual luciferase reporter assay and qPCR were used to confirm the interaction between DANCR and the WNT pathway during DE differentiation. ResultsThe in vitro differentiation system mimicked DE differentiation efficiently. And the expression of DANCR was gradually downregulated during differentiation. DANCR was efficiently knocked down in the shDANCR hESC line （P < 0.001）. Compared with those in the control group， the expression levels of primitive markers Brachyury （T）， EOMES， MIXL1 and GSC， as well as DE markers SOX17 and FOXA2， were significantly decreased in shDANCR groups （P < 0.05）. Furthermore， the transcriptional activity of the WNT pathway in shDANCR groups was lower than that in the control group （P < 0.05）. And RNA levels of downstream genes of the WNT pathway， FZD5， FZD8， SFRP1， FRZB and ANKRD6， were significantly decreased in shDANCR groups （P < 0.05）. However， differences in protein levels of the TGFβ pathway effectors SMAD2/3 and p-SMAD2 were statistically insignificant in shDANCR and control groups （P > 0.05）. Forced activation of β-CATENIN rescued DANCR knock down-induced deficiency in DE differentiation. ConclusionsThe expression of DANCR decreases during DE differentiation. DANCR may promote DE differentiation through modulating the activity of the WNT pathway.

Long Non-Coding RNA Dancr Affects Myocardial Fibrosis in Atrial Fibrillation Mice via the MicroRNA-146b-5p/Smad5 Axis.

Objectives: Atrial fibrillation (AF) is the most frequent arrhythmia, and myocardial fibrosis (MF) has a close association with atrial remodeling and leads to AF. This study aimed to explore the function of the long non-coding RNA (lncRNA) differentiation antagonizing non-protein coding RNA (Dancr)/microRNA (miR)-146b-5p/Smad5 axis on MF in AF mice. Methods: AF mouse models were established. Overexpression Dancr lentivirus was injected into AF mice to increase Dancr expression in myocardial tissues. LncRNA Dancr, miR-146b-5p, and Smad5 expression levels and inflammatory factors (IL-18 and TNF-α) in the myocardial tissues were measured. MF was measured and the expression levels of MF-related genes (COL1A1, α-SMA, and FN1) were detected. In addition, in vitro HL-1 cell rapid pacing models were constructed, and after lncRNA Dancr and miR-146b-5p-related construct transfection, cell viability and cell apoptosis were determined. Results: LncRNA Dancr up-regulation ameliorated MF in the AF mice, reduced IL-18 and TNF-α expression levels in myocardial tissues, and decreased COL1A1, α-SMA, and FN1 expression levels. The in vitro HL-1 cell rapid pacing models suggested that miR-146b-5p overexpression reversed the inhibitory effects of lncRNA Dancr overexpression on MF in HL-1 cells, and Smad5 interference reversed the ameliorative effects of miR-146b-5p interference on MF in HL-1 cells. Conclusions: LncRNA Dancr can sponge miR-146b-5p to promote Smad5 expression, thereby delaying MF in AF mice.

Inhibition of lncRNA DANCR Prevents Heart Failure by Ameliorating Cardiac Hypertrophy and Fibrosis Via Regulation of the miR-758-3p/PRG4/Smad Axis.

The current work was developed to explore the functions and possible mechanism of PRG4 in cardiac hypertrophy and heart failure. Ang II-stimulated H9c2 cells and AC16 cells were used as in vitro cell models. The binding relation between genes in cells was explored using luciferase reporter assays and RNA immunoprecipitation assay. The cardiac functions of rats received transverse-ascending aortic constriction (TAC) surgery and adeno-associated virus (AAV) injection were examined with echocardiography. The myocardial histological changes were observed using H&E, wheat germ agglutinin, and sirius red staining. It was discovered that PRG4 silencing attenuated cell hypertrophy and fibrosis and inactivated the Smad pathway under Ang II treatment. PRG4 was targeted by miR-758-3p, and miR-758-3p interacted with long noncoding RNA DANCR. DANCR silencing inhibited cardiac dysfunction, fibrosis, and TGFß1/Smad pathway. In addition, DANCR was highly expressed in myocardial extracellular vesicles. Overall, DANCR depletion prevents heart failure by inhibiting cardiac hypertrophy and fibrosis via the miR-758-3p/PRG4/Smad pathway.

Corrigendum: METTL3 contributes to osteosarcoma progression by increasing DANCR mRNA stability via m6A modification.

[This corrects the article DOI: 10.3389/fcell.2021.784719.].

Evaluation of the expression level of some coding and non-coding genes in oral squamous cell carcinoma.

INTRODUCTION: Oral squamous cell carcinoma (OSCC) is the most common cancers arising from the head and neck region. There is growing evidence that lncRNAs play an important role in OSCC progression. The study aims to investigate correlations between the expression levels of LncRNAs of PARROT, MYCNUT, DANCR, and KTN1-AS1 with clinicopathological characteristics and finding suitable biomarkers for OSCC. MATERIAL AND METHOD: Total lncRNAs related to cancers and HNSC trascriptomics data were downloaded from lncRNADisease v2.0 database and xenabrowser, respectively. Then, ACO was perfomed on shared of LncRNAs between two databases. Finally, some lncRNAs were proposed as potential biomarkers. Thirty biopsies samples from patients with the OSCC and 30 healthy subjects were collected by the surgery. Questionnaires including clinical and demographic data were filled for all cases. Using Real-time PCR, the expression levels of PARROT, MYCNUT, DANCR, and KTN1-AS1 lncRNAs were quantified. RESULT: According to the results,17 novel gene symbol was identified.All the candidate lncRNAs the expression levels of PARROT, MYCNUT, DANCR, and KTN1-AS1 were remarkably upregulated in OSCC tumors in comparison with control group (RQ: 10.00 (P < 0.0001), RQ: 2.920 (P < 0.0001), RQ: 1.623 (P = 0.002), and 4.467 (P < 0.0001), respectively). Also, we found significant associations between tumor lncRNAs expression of PARRPT and DANCER and tumor metastasis (P = 0.009, and P = 0.005, respectively). Additionally, lncRNA KTN1-AS1 expression level was significantly higher in the patients with tumor size more than 3 cm, in comparison with tumor less than 3 cm (P = 0.005). According ROC analysis, all these candidate lncRNAs can be a significant predictor for OSCC (AUC of PARROT lncRNA = 69.72%, AUC of MYCNUT = 98.22%, AUC of DANCR = 74.83%, and AUC of KTN1-AS1 = 99.22%). CONCLUSION: we found that overexpression levels of PARROT, MYCNUT, DANCR, and KTN1-AS1 lncRNAs were correlated with poor clinicopathological characteristics in patients with OSCC. Also, PARROT, MYCNUT, DANCR, and KTN1-AS1 are novel biomarker for the detection of OSCC.

LncRNA DANCR restrained the survival of mycobacterium tuberculosis H37Ra by sponging miR-1301-3p/miR-5194.

Tuberculosis is a worldwide contagion caused by Mycobacterium tuberculosis (MTB). MTB is characterized by intracellular parasitism and is semi-dormant inside host cells. The persistent inflammation caused by MTB can form a granuloma in lesion regions and intensify the latency of bacteria. In recent years, several studies have proven that long non-coding RNAs (lncRNAs) play critical roles in modulating autophagy. In our study, the Gene Expression Omnibus (GEO) databases were searched for lncRNAs that are associated with tuberculosis. We found that lncRNA differentiation antagonizing non-protein coding RNA (DANCR) increased in the peripheral blood samples collected from 54 pulmonary tuberculosis patients compared to 23 healthy donors. By constructing DANCR overexpression cells, we analyzed the possible cellular function of DANCR. After analyzing our experiments, it was found that the data revealed that upregulation of DANCR facilitated the expression of signal transducer and activator of transcription 3, autophagy-related 4D cysteine peptides, autophagy-related 5, Ras homolog enriched in the brain, and microtubule-associated protein 1A/1B light chain 3 (STAT3, ATG4D, ATG5, RHEB, and LC3, respectively) by sponging miR-1301-3p and miR-5194. Immunofluorescence analysis indicated that DANCR played a positive role in both autophagosome formation and fusion of autolysosomes in macrophages. The colony-forming unit (CFU) assay data also showed that the cells overexpressing DANCR were more efficient in eliminating the intracellular H37Ra strain. Consequently, these data suggest that DANCR restrained intracellular survival of M. tuberculosis by promoting autophagy via miR-1301-3p and miR-5194.

LncRNA DANCR Enhances Angiogenesis to Promote Melanoma Progression Via Sponging miR-5194.

Background and aim: As an oncogenic long noncoding RNA, differentiation antagonizing non-protein coding RNA (DANCR) was identified in many kinds of cancers. However, the specific function of DANCR in melanoma remains unclear. Here, we aimed to clarify the role of DANCR played in melanoma progression and the underlying mechanisms. Methods: TCGA data base and patients' tissue samples were used to analyzed the function of DANCR in melanoma progression. Transwell assay was used to detect cell migration and tube formation assay was employed to assess the ability of angiogenesis. Western blot, qRT-PCR, ELISA and IHC assay were used to examine VEGFB expression and secrection. Luciferase assay verified the binding of DANCR and miRNA. Results: We found that the expression of DANCR was positively related to poor clinical prognosis of melanoma. DANCR knockdown suppressed melanoma progression with a more significant suppression in vivo compared with it in vitro. Further detection showed that beyond promoting proliferation, DANCR also enhanced angiogenesis via upregulating VEGFB. Mechanistic analysis revealed that DANCR upregulating VEGFB through sponging miR-5194, which negatively regulated VEGFB expression and secretion. Conclusion: We demonstrated a novel oncogenic role DANCR played in melanoma and suggested a new avenue for melanoma therapy by targeting the DANCR/miR-5194/VEGFB signaling.

LncRNA DANCR deficiency promotes high glucose-induced endothelial to mesenchymal transition in cardiac microvascular cells via the FoxO1/DDAH1/ADMA signaling pathway.

Cardiac fibrosis is the main pathological basis of diabetic cardiomyopathy (DCM), and endothelial-to-meschenymal transition (EndMT) is a key driver to cardiac fibrosis and plays an important role in the pathogenesis of DCM. Asymmetric dimethylarginine (ADMA), a crucial pathologic factor in diabetes mellitus, is involved in organ fibrosis. This study aims to evaluate underlying mechanisms of ADMA in DCM especially for EndMT under diabetic conditions. A diabetic rat model was induced by streptozotocin (STZ) injection, and human cardiac microvascular endothelial cells (HCMECs) were stimulated with high glucose to induce EndMT. Subsequently, the role of ADMA in EndMT was detected either by exogenous ADMA or by over-expressing dimethylarginine dimethylaminohydrolase 1 (DDAH1, degradation enzyme for ADMA) before high glucose stimulation. Furthermore, the relationships among forkhead box protein O1 (FoxO1), DDAH1 and ADMA were evaluated by FoxO1 over-expression or FoxO1 siRNA. Finally, we examined the roles of LncRNA DANCR in FoxO1/DDAH1/ADMA pathway and EndMT of HCMECs. Here, we found that EndMT in HCMECs was induced by high glucose, as evidenced by down-regulated expression of CD31 and up-regulated expression of FSP-1 and collagen Ⅰ. Importantly, ADMA induced EndMT in HCMECs, and over-expressing DDAH1 protected from developing EndMT by high glucose. Furthermore, we demonstrated that over-expression of FoxO1-ADA with mutant phosphorylation sites of T24A, S256D, and S316A induced EndMT of HCMECs by down-regulating of DDAH1 and elevating ADMA, and that EndMT of HCMECs induced by high glucose was reversed by FoxO1 siRNA. We also found that LncRNA DANCR siRNA induced EndMT of HCMECs, activated FoxO1, and inhibited DDAH1 expression. Moreover, over-expression of LncRNA DANCR could markedly attenuated high glucose-mediated EndMT of HCMECs by inhibiting the activation of FoxO1 and increasing the expression of DDAH1. Collectively, our results indicate that LncRNA DANCR deficiency promotes high glucose-induced EndMT in HCMECs by regulating FoxO1/DDAH1/ADMA pathway.

Decreased DANCR contributes to high glucose-induced extracellular matrix accumulation in human renal mesangial cell via regulating the TGF-ß/Smad signaling.

Glomerulosclerosis is one of the major histopathologic changes in diabetic kidney diseases (DKD), which is characterized by excessive deposition of extracellular matrix (ECM) in the glomerulus mainly produced by mesangial cells in response to transforming growth factor-ß (TGF-ß) stimuli under diabetic conditions. Despite TGF-ß has been implicated as a major pathogenic factor in the development of diabetic glomerulosclerosis, clinical trials of monoclonal antibodies against TGF-ß failed to demonstrate therapeutic benefits. Thus, developing alternative therapeutic strategies to effectively block the TGF-ß/Smad signaling could be of paramount importance for DKD treatment. Emerging evidence indicates that dysregulation of certain lncRNAs can lead to aberrant activation of TGF-ß/Smad signaling. Herein, we identified a novel lncRNA, named DANCR, which could efficiently function as a negative regulator of TGF-ß/Smad signaling in mesangial cells. Ectopic expression of DANCR could specifically block the activation of TGF-ß/Smad signaling induced by high-glucose or TGF-ß in human renal mesangial cells (HRMCs). Mechanistically, DANCR functions to stabilize nemo-like kinase (NLK) mRNA through interaction with insulin-like growth factor 2 mRNA-binding protein 2 (IGF2BP2), resulting in enhanced phosphorylating on the linker region of activated Smad2/3 in the nucleus. Taken together, our data have uncovered an lncRNA-based regulatory modality of the TGF-ß/Smad signaling and identified DANCR as an endogenous blocker of TGF-ß/Smad signaling in HRMCs, which may represent a potential therapeutic target against the diabetic glomerulosclerosis.

Long non-coding RNA DANCR alleviates acute myocardial infarction damage via regulating microRNA-509-5p/KLF transcription factor 13 pathway.

Acute myocardial infarction (AMI) is the most important cause of death among cardiovascular diseases. Long noncoding RNAs (lncRNAs) have been widely implicated in the regulation of AMI progression. Discrimination antagonizing nonprotein coding RNA (DANCR) alleviated hypoxia-caused cardiomyocyte damages, and the underlying mechanisms remain unclear. Here, we investigated the function and mechanism of DANCR in hypoxia-induced cardiomyocytes and AMI model by enzyme-linked immunosorbent assay, reactive oxygen species and adenosine triphosphate measurement, and mitochondrial activity determination. Additionally, luciferase reporter assay, immunoblotting, and qRT-PCR were performed to validate the interactions between DANCR/miR-509-5p and miR-509-5p/Kruppel-like factor 13 (KLF13). The role of DANCR was also verified in AMI model by overexpression. Our results showed that DANCR expression was significantly downregulated in hypoxia-induced cardiomyocytes or AMI model. Overexpression of DANCR significantly alleviated mitochondrial damages, reduced inflammation, and improved cardiac function in the AMI model. Furthermore, we demonstrated that miR-509-5p/KLF13 axis mediated the protective effect of DANCR. The current study highlighted the critical role of DANCR in alleviating AMI progression through targeting the miR-509-5p/KLF13 signaling axis, suggesting that DANCR may serve as a potential diagnostic marker or therapeutic target for AMI.

Expression analysis of Rho GTPase-related lncRNAs in breast cancer.

The Rho GTPases have prominent roles in cell cycle transition and cell migration. Some members of this family have been found to be mutated in cancers. Moreover, alterations in expression levels and/or activity of these proteins have been reported in many types of cancers. Thus, Rho GTPases are involved in the carcinogenesis. Rho GTPases regulate growth, motility, invasiveness and metastatic ability of breast cancer cells. Long non-coding RNAs (lncRNAs) have been revealed to exert significant effect in the regulation of these proteins via direct routes or through sequestering microRNAs that inhibit Rho GTPases. We aimed to assess expression levels of four Rho GTPase-related lncRNAs, namely NORAD, RAD51-AS1, NRAV and DANCR in breast cancer samples versus non-cancerous specimens from the same individuals. Expression levels of NORAD were shown to be elevated in tumoral tissues compared with non-tumoral tissues (Expression ratio (95% CI)= 5.85 (3.16-10.83), Standard error of mean (SEM)= 0.44, P value< 0.0001). NRAV expression was also higher in tumoral tissues compared with control tissues (Expression ratio=2.85 (1.52-5.35), SEM= 0.45, P value= 0.0013). Similar to these lncRNAs, RHOA was demonstrated to be up-regulated in malignant tissues (Expression ratio=6.58 (3.17-13.63), SEM= 0.52, P value< 0.0001). Although expression ratio values showed up-regulation of RAD51-AS1 and DANCR in cancerous tissues (Expression ratio (95% CI)= 2.2 (1.05-4.6) and 1.35 (0.72-2.53), respectively), P values did not reach significance level (P values=0.0706 and 0.3746, respectively). There were significant associations between expression level of NRAV gene in tumor tissues and a number of parameters including age, histological tumor grade and tubule formation. Taken together, the current study shows dysregulation of a number of RHOA-related lncRNAs in breast cancer in association with abnormal up-regulation of this member of Rho GTPase family and suggests conduction of additional functional studies to unravel their mode of participation in the breast carcinogenesis.