LncRNA NEAT1 aggravates human microvascular endothelial cell injury by inhibiting the Apelin/Nrf2/HO-1 signalling pathway in type 2 diabetes mellitus with obstructive sleep apnoea

Long noncoding RNAs (lncRNAs) regulate the progression of type 2 diabetes mellitus complicated with obstructive sleep apnoea (T2DM-OSA). However, the role of the lncRNA nuclear paraspeckle assembly transcript 1 (NEAT1) in T2DM-OSA remains unknown. This study aimed to reveal the function of NEAT1 in T2DM-OSA and the underlying mechanism. KKAy mice were exposed to intermittent hypoxia (IH) or intermittent normoxia to generate a T2DM-OSA mouse model. HMEC-1 cells were treated with high glucose (HG) and IH to construct a T2DM-OSA cell model. RNA expression was detected by qRT-PCR. The protein expression of Apelin, NF-E2-related factor 2 (Nrf2), haem oxygenase-1 (HO-1), and up-frameshift suppressor 1 (UPF1) was assessed using western blot. Cell injury was evaluated using flow cytometry, enzyme-linked immunosorbent assay, and oxidative stress kit assays. RIP, RNA pull-down, and actinomycin D assays were performed to determine the associations between NEAT1, UPF1, and Apelin. NEAT1 expression was upregulated in the aortic vascular tissues of mice with T2DM exposed to IH and HMEC-1 cells stimulated with HG and IH, whereas Apelin expression was downregulated. The absence of NEAT1 protected HMEC-1 cells from HG- and IH-induced damage. Furthermore, NEAT1 destabilized Apelin mRNA by recruiting UPF1. Apelin overexpression decreased HG- and IH-induced injury to HMEC-1 cells by activating the Nrf2/HO-1 pathway. Moreover, NEAT1 knockdown reduced HG- and IH-induced injury to HMEC-1 cells through Apelin. NEAT1 silencing reduced HMEC-1 cell injury through the Apelin/Nrf2/HO-1 signalling pathway in T2DM-OSA.Abbreviations: LncRNAs, long non-coding RNAs; T2DM, type 2 diabetes mellitus; OSA, obstructive sleep apnoea; NEAT1, nuclear paraspeckle assembly transcript 1; IH, intermittent hypoxia; HMEC-1, human microvascular endothelial cells; HG, high glucose; Nrf2, NF-E2-related factor 2; UPF1, up-frameshift suppressor 1; HO-1, haem oxygenase-1; qRT-PCR, quantitative real-time polymerase chain reaction; ELISA, enzyme-linked immunosorbent assay; GAPDH, glyceraldehyde 3-phosphate dehydrogenase; TNF-α, tumour necrosis factor-α; CCK-8, Cell Counting Kit-8; IL-1β, interleukin-1β; ROS, reactive oxygen species; MDA, malondialdehyde; SOD, superoxide dismutase; RIP, RNA immunoprecipitation; SD, standard deviations; GSH, glutathione; AIS, acute ischaemic stroke; HMGB1, high mobility group box-1 protein; TLR4, toll-like receptor 4.

LncRNA NEAT1 promotes MPP+ induced injury of PC12 cells and accelerates the progression of Parkinson's disease in mice through FUS mediated inhibition of PI3K/AKT/mTOR signalling pathway

Long noncoding RNA nuclear-enriched abundant transcript 1 (NEAT1) is involved in the progression of Parkinson's disease (PD), but the specific regulatory role needs further exploration. This study showed that the expression of NEAT1 was upregulated in the cerebrospinal fluid (CSF) and peripheral blood of patients with different stages of PD. 1-Methyl-4-phenylpyridine (MPP)-treated PC 12 cells were transfected with si-NEAT1, and MPP treatment promoted cell apoptosis, oxidative stress and inflammatory factor secretion. Si-NEAT1 reversed the effects of MPP. NEAT1 silencing eliminated the effect of MPP on the protein expression levels of LC3-II and p62/SQSTM1. By using an online bioinformatics database, Fused in Sarcoma (FUS) was confirmed to be an RNA binding protein of NEAT1, and it was highly expressed in the CSF and peripheral blood of patients with PD. Si-FUS was transfected into MPP-treated PC 12 cells to detect cell apoptosis, oxidative stress, inflammatory factor secretion and autophagy, and the results were the same as those of transfection of si-NEAT1. Furthermore, MPP treatment reduced the phosphorylation levels of PI3K, Akt and mTOR, whereas si-FUS reversed the effects of MPP. In vivo, compared with the model group, the PD mice showed reduced NEAT1 and FUS expression levels and activated PI3K pathway after being injected with si-NEAT1. The brain tissue of NEAT1-silenced PD mice had decreased inflammatory infiltration and apoptosis and increased neurological scores. In conclusion, NEAT1 is involved in PD progression through FUS-mediated inhibition of the PI3K/AKT/mTOR signalling pathway.

LncRNA-NEAT1 blocks the Wnt/β-catenin signaling pathway by targeting miR-217 to inhibit trophoblast cell migration and invasion

OBJECTIVE

This study aimed to study the correlation between preeclampsia (PE) and lncRNA nuclear paraspeckle assembly transcript 1 (NEAT1), and to examine the molecular mechanisms behind the development of PE.

METHODS

30 PE and 30 normal pregnant women placental samples were assessed the levels of NEAT1 and miR-217 by quantitative real-time PCR (qRT-PCR). The trophoblast cell line HTR8/SVneo was used for silencing NEAT1 or miR-217 inhibitor in the absence or presence of an inhibitor and H2O2. Cell counting Kit 8 (CCK-8), flow cytometry, and Transwell were used to detect cell proliferation, apoptosis, migration, and invasion. Luciferase reporter gene assay was utilized to verify the binding between miR-217 and Wnt family member 3 (Wnt3), and between the miR-217 and NEAT1. Proteins related to the Wnt/β-catenin signaling pathway were detected using western blotting.

RESULTS

The PE group exhibited a significantly downregulated expression of miR-217 and a significantly upregulated expression of NEAT1. NEAT1 targeted miR-217, and Wnt is a miR-217 target gene. siRNA-NEAT1 inhibited the apoptosis of trophoblast cells, but promoted their invasion, migration, and proliferation. MiR-217 inhibitor could partially reverse the effects of siRNA-NEAT1. The expression of the Wnt/β-catenin signaling pathway-related proteins, WNT signaling pathway inhibitor 1 (DKK1), cyclin-D1 and β-catenin, was significantly increased after siRNA-NEAT1.

CONCLUSIONS

NEAT1 could reduce trophoblast cell invasion and migration by suppressing miR-217/Wnt signaling pathway, leading to PE.

Modulation of lncRNA NEAT1 overturns the macrophages based immune response in M. tuberculosis infected patients via miR-373 regulation

There is a lack of studies which explore and clarify the interactions that occur between host macrophage and Mycobacterium tuberculosis with regard to microRNA such as LNCNEAT1 and miR-373. The current study determines the mechanisms involved in the control of M. tuberculosis infection by macrophage using LNCNEAT1 and miR-373. The researchers collected different samples from healthy individuals, pulmonary TB patients, and samples like hMDMs cells and H37Rv infected MTB to determine the concentrations of inflammatory factors. The impact of NEAT1 and miR-373 upon macrophages was analyzed in NEAT1-specific siRNA (si-NEAT1), NEAT1 over-expression vector (pcDNA3.1-NEAT1), miR-373 mimic, miR-373 inhibitor (anti-miR-373), and negative control, and macrophages infected with H37Ra. The results inferred that among pulmonary TB patients, NEAT1 got heavily expressed while the expression level of miR-373 was poor. The number of inflammatory factors with pulmonary TB was notably higher. This got further amplified in macrophages after being infected with H37Ra, while no such observations found for miR-373. During post-transfection, low concentration of inflammatory factors was observed while the cells in si-NEAT1 group got proliferated in low volume compared to both pcDNA3.1-NEAT1 group and NEAT1 negative control group. However, the capability of apoptosis was higher compared to the other two groups (p < 0.05). There was an increase observed in inflammatory factors as well as proliferation in anti-miR-373 group compared to miR-373 mimics and miR-373-negative control group while a significant decline was observed in apoptosis. LNCNEAT1 aggravated the number of inflammatory factors in macrophages that got infected with MTB while on the other end, it mitigated both phagocytosis as well as the cellular immunity of macrophages. In addition to this, it enhanced the proliferation of infected cells and inhibited apoptosis via targeted regulation of miR-373, thus resulting in the development of TB.

LncRNA NEAT1 promotes angiogenesis of retinoblastoma cells through regulation of the miR-106a/HIF-1α axis

Objective

To explore the role and mechanisms of lncRNA nuclear enriched abundant transcript 1 (NEAT1) in angiogenesis of retinoblastoma (RB) cells.

Methods

This study investigated the roles of NEAT1 in RB progression. The RNA expression levels of NEAT1, miR-106a, and hypoxia-inducible factor-1alpha (HIF-1α) examined by quantitative reverse transcription polymerase chain reaction (RT-qPCR) were compared between RB cells and normal retinal pigment epithelial (RPE) cells. The binding sites between NEAT1 and miR-106a, and between miR-106a and HIF-1α were predicted by the TargetScan database and verified using the dual-luciferase reporter assay. By transfection of overexpression plasmid or shRNA of NEAT1, and/or treatment of miR-106a inhibitor or mimics, proliferation, invasion, and angiogenesis of RB cells (measured by the MTT assay, the Transwell assay, and the tube formation assay, respectively) were compared between groups. Group comparisons were analyzed using one-way analysis of variance (ANOVA), and Tukey's post-hoc test was employed for further statistical assessment. P-value less than 0.05 was considered statistically significant.

Results

The RNA expression levels of NEAT1 and HIF-1α were upregulated in RB cells, whereas the expression level of miR-106a was downregulated compared with RPE cells. NEAT1 overexpression or miR-106a knockdown advanced proliferation, invasion, and tube formation of RB cells. As a target of NEAT1, miR-106a could sponge HIF-1α to downregulate HIF-1α expression level. Functional analyses indicated that miR-106a knockdown reversed the inhibitory effects of NEAT1 silencing on the proliferation, invasion, and tube formation of RB cells. Furthermore, miR-106a overexpression suppressed RB cell angiogenesis by downregulating HIF-1α expression level.

Conclusion

NEAT1 promoted proliferation, invasion, and angiogenesis of RB cells through upregulation of HIF-1α expression level by sponging miR-106a, demonstrating that NEAT1 may be a novel target for RB treatment.

ZNF143 inhibits hepatocyte mitophagy and promotes non-alcoholic fatty liver disease by targeting increased lncRNA NEAT1 expression to activate ROCK2 pathway

BACKGROUND

Nonalcoholic fatty liver disease (NAFLD) is the most common hepatic disorders worldwide. The mitophagy is suggested to be repressed in NAFLD, but the mechanism remains to be elucidated.

METHODS

NAFLD cell and mouse models were established by treating with free fatty acid (FFA) and feeding a high fat diet (HFD), respectively. QRT-PCR, Western blotting, or IHC measured the expression of ZNF143, lncRNA NEAT1, ROCK2, and lipid formation/mitophagy-related proteins. Cell viability and mitophagy were evaluated by MTT and immunofluorescence. The chloroform-methanol extraction method measured triglyceride and total cholesterol levels. ELISA detected ALT and AST levels. The interactions among ZNF143, lncRNA NEAT1 and SND1 were analysed by ChIP, dual-luciferase reporter, pull-down, and RIP. The lipid droplets were determined by Oil-red O and HE staining.

RESULTS

ZNF143 and lncRNA NEAT1 were upregulated in hepatic cells treated with FFA (p < 0.01 and p < 0.001). Knockdown of ZNF143 or lncRNA NEAT1 inhibited lipid droplets formation, while promoting mitophagy (p < 0.01 and p < 0.001). ZNF143 promoted lncRNA NEAT1 transcriptional expression through binding to its promoter. LncRNA NEAT1 increased ROCK2 mRNA stability by targeting SND1. LncRNA NEAT1 or ROCK2 overexpression reversed the effect of ZNF143 or lncRNA NEAT1 knockdown on hepatic steatosis and mitophagy (p < 0.01 and p < 0.001). ZNF143 or lncRNA NEAT1 knockdown inhibited HFD-induced steatosis and promoted mitophagy in vivo (p < 0.01 and p < 0.001).

CONCLUSION

The upregulation of lncRNA NEAT1 caused by ZNF143 promoted NAFLD through inhibiting mitophagy via activating ROCK2 pathway by targeting SND1, providing potential targets for NAFLD therapy.

lncRNA NEAT1 mediates LPS-induced pyroptosis of BEAS-2B cells via targeting miR-26a-5p/ROCK1 axis

Acute lung injury (ALI) is an adverse disease of the respiratory system, and one of its prevalent causes is sepsis induction. Cell pyroptosis facilitates the progression of ALI and lncRNAs play critical roles in ALI. Thus, this research seeks to investigate the specific mechanism of NEAT1 in sepsis-ALI.BEAS-2B cells were exposed to lipopolysaccharide (LPS) to construct a cell model of sepsis-induced ALI. The gene and protein expression were assessed using qRT-PCR and western blot. Cell viability was identified by CCK-8. Cell death was discovered using PI staining. The secretion of IL-1β and IL-18 was examined using ELISA. The interconnections among NEAT1, miR-26a-5p, and ROCK1 were confirmed using starbase, luciferase assay, and RIP.LPS treatment augmented NEAT1 and ROCK1 levels while mitigating miR-26a-5p level in BEAS-2B cells. Additionally, LPS treatment facilitated cell death and cell pyroptosis, whereas NEAT1 silencing could reverse these effects in BEAS-2B cells. Mechanistically, NEAT1 positively mediated ROCK1 expression by targeting miR-26a-5p. Furthermore, miR-26a-5p inhibitor offset NEAT1 depletion-mediated suppressive effects on cell death and cell pyroptosis. ROCK1 upregulation decreased the inhibitory impacts produced by miR-26a-5p overexpression on cell death and cell pyroptosis. Our outcomes demonstrated NEAT1 could reinforce LPS-induced cell death and cell pyroptosis by repressing the miR-26a-5p/ROCK1 axis, thereby worsening ALI caused by sepsis. Our data indicated NEAT1, miR-26a-5p, and ROCK1 might be biomarkers and target genes for relieving sepsis-induced ALI.

LncRNA NEAT1 inhibits apoptosis and autophagy of ovarian granulosa cells through miR-654/STC2-mediated MAPK signaling pathway

Long non-coding RNA (lncRNA) anomalies cause early ovarian failure. LncRNA nuclear enriched abundant transcript 1 (NEAT1) was down-regulated in premature ovarian failure (POF) mice and connected to the illness, however, the mechanism remained unclear. The levels of gene and protein were measured by using quantitative real-time polymerase chain reaction, Western blot, and immunofluorescence. Follicle stimulating hormone (FSH), estradiol (E2), and luteinizing hormone (LH) levels were determined using enzyme-linked immunosorbent assay (ELISA). 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide (MTT) and flow cytometry were used to determine cell viability and apoptosis. The interaction of NEAT1, miR-654, and stanniocalcin-2 (STC2) was verified by dual-luciferase reporter assay or RNA binding protein immunoprecipitation (RIP) assays. The results showed NEAT1 and STC2 down-regulated, while miR-654 up-regulated in POF mice. Overexpression of NEAT1 reduced apoptosis and autophagy in cyclophosphamide (CTX)-treated ovarian granulosa cells (OGCs), and Bax, cleaved-caspase3, LC3B, LC3II/LC3I ratio were decreased and Bcl-2 and p62 were raised. NEAT1 suppressed miR-654 expression by directly targeting miR-654. The inhibition of NEAT1 overexpression on apoptosis and autophagy in OGCs was reversed by miR-654 mimics. STC2 was a target gene of miR-654, and miR-654 inhibitor reduced the apoptosis and autophagy by regulating the STC2/MAPK axis. To sum up, NEAT1 reduced miR-654 expression and modulated the STC2/MAPK pathway to decrease apoptosis and autophagy in POF, indicating a potential therapeutic target.

LncRNA NEAT1 accelerates renal fibrosis progression via targeting miR-31 and modulating RhoA/ROCK signal pathway

Renal fibrosis is the final pathway for chronic kidney disease to end-stage renal failure. Noncoding RNAs have been reported to play a crucial role in renal fibrosis. Here, the effects of long noncoding RNA (lncRNA) nuclear-enriched abundant transcript 1 (NEAT1) and miR-31 on renal fibrosis and their regulatory mechanism were evaluated. RT-qPCR was used to assess NEAT1, miR-31, and RhoA levels. Western blot was performed to analyze the expression of fibrosis markers, RhoA, rho-related kinase (ROCK1), and connective tissue growth factor (CTGF). RNA immunoprecipitation (RIP), fluorescence in situ hybridization (FISH), and luciferase reporter assays verified the interaction between miR-31 and NEAT1 or RhoA. Renal fibrosis and injury were observed by Masson and hematoxylin and eosin (H&E) staining. The expression level of inflammatory cytokines was detected by ELISA. Immunohistochemistry (IHC) was performed to examine the expression levels of α-smooth muscle actin (α-SMA) and RhoA in renal tissues. We showed that NEAT1 was highly expressed, whereas miR-31 was decreased in renal fibrosis. NEAT1 was found to directly bind miR-31 to positively regulate RhoA expression. Furthermore, NEAT1 silencing inhibited renal fibrosis and inflammation and suppressed the RhoA/ROCK1 signaling pathway. However, knockdown of miR-31 could reverse these effects. NEAT1 silencing or overexpression of miR-31 alleviated renal fibrosis in vivo. In conclusion, NEAT1 accelerates renal fibrosis progression via negative regulation of miR-31 and the activation of RhoA/ROCK1 pathway, thereby upregulating the expression level of CTGF, providing a theoretical basis for treatment and prognostic evaluation of renal fibrosis.

MiR-490-3p Sponged by lncRNA NEAT1 Can Attenuate Lung Adenocarcinoma Progression by Suppressing the RhoA/ROCK Signaling Pathway

OBJECTIVE

Long noncoding RNAs (lncRNAs) are crucial regulators of lung adenocarcinoma (LUAD) progression. Herein, we explored the role of miR-490-3p and the underlying molecular mechanism involving key lncRNAs and pathways in LUAD.

METHODS

Reverse transcription-quantitative PCR (RT-qPCR) was performed to detect the expression of lncRNA NEAT1 and miR-490-3p in LUAD cells and tissues. Western blotting was used to determine protein expression levels of the Ras homologous gene family member A/Rho-related protein kinase (RhoA/ROCK) signal pathway marker. Considering cell functions, Cell Counting Kit-8 (CCK-8), Transwell, and xenograft experiments were employed to evaluate LUAD cell proliferation, migration, and tumor growth, respectively. The relationship between miR-490-3p and lncRNA NEAT1 was analyzed using a luciferase reporter assay.

RESULTS

Herein, we found that miR-490-3p expression was significantly low in LUAD cells and tissues. MiR-490-3p overexpression markedly suppressed tumor growth, the RhoA/ROCK signaling pathway, migration, and proliferation of LUAD cells. Moreover, lncRNA NEAT1, which is highly expressed in LUAD, was detected upstream of miR-490-3p. Upregulation of lncRNA NEAT1 exacerbated the behavior of LUAD cells and offset the suppressive influence of miR-490-3p-mediated upregulation on malignant LUAD cell behavior.

CONCLUSION

MiR-490-3p sponging by lncRNA NEAT1 could hamper LUAD progression by inhibiting the RhoA/ROCK signaling pathway. These findings provide new insights for LUAD diagnosis and treatment.

Tetrandrine-induced downregulation of lncRNA NEAT1 inhibits rheumatoid arthritis progression through the STAT3/miR-17-5p pathway

BACKGROUND

The inhibitory effect of Tetrandrine (Tet) on rheumatoid arthritis (RA) is well established. However, its exact molecular mechanism remains unknown.

METHODS

RT-qPCR coupled with western blotting was employed to analyze the expression of NEAT1, miR-17-5p, and STAT3 in RA tissues and/or RA-fibroblast-like synoviocytes (RA-FLS) treated with 3 μmol/L of Tet for 48 h. Cell Counting Kit-8 assay and flow cytometry were performed to assess RA-FLS proliferation and apoptosis. Luciferase reporter assays were used to validate the interactions between miR-17-5p and STAT3 or NEAT1.

RESULTS

The expression of NEAT1 decreased in a time-dependent manner upon Tet treatment. Tet significantly inhibited RA-FLS proliferation and triggered apoptosis by downregulating NEAT1 expression. Additionally, NEAT1 directly targeted miR-17-5p to upregulate STAT3 expression. Tet-induced low NEAT1 expression impaired RA-FLS growth by targeting miR-17-5p and inhibiting STAT3.

CONCLUSION

Tet exerts its inhibitory role in RA progression by regulating the NEAT1/miR-17-5p/STAT3 pathway.

lncRNA NEAT1 promotes hypoxia-induced inflammation and fibrosis of alveolar epithelial cells via targeting miR-29a/NFATc3 axis

The objective of the present study was to explore the function and mechanism of long noncoding RNA (lncRNA) nuclear paraspeckle assembly transcript 1 (NEAT1) in pulmonary fibrosis (PF) progression. HPAEpic cells and A549 cells were exposed to hypoxic conditions to establish an in vitro model. Cell apoptosis was detected by TUNEL assay, and inflammatory cytokine levels were detected by ELISA. Gene and protein expression levels were identified by qRT-PCR and Western blot assays, respectively. The interaction among NEAT1, miR-29a, and NFATc3 was identified by dual-luciferase reporter and RNA pull-down assays. In hypoxia-treated cells, hypoxia markers (HIF-1α and HIF-2α), cytokines (TNF-α, IL-1β, and IL-6) and fibrotic markers (α-SMA, collagen I and collagen III) were significantly enhanced. Consistently, the expression levels of NEAT1 and NFATc3 were increased, but miR-29a was decreased in hypoxia-stimulated cells. Knockdown of NEAT1 significantly decreased cell apoptosis and the releases of TNF-α, IL-1β, and IL-6 as well as reduced the levels of α-SMA, collagen I, and collagen III. Moreover, NEAT1 positively regulated NFATc3 expression by directly targeting miR-29a. Functional experiments showed that the anti-apoptotic, anti-inflammatory, and anti-fibrotic effects mediated by NETA1 silencing were impeded by miR-29a inhibition or NFATc3 overexpression in hypoxia-stimulated HPAEpic and A549 cells. Collectively, these data demonstrated that NEAT1 knockdown inhibited hypoxia-induced cell apoptosis, inflammation, and fibrosis by targeting the miR-29a/NFATc3 axis in PF, suggesting that NEAT1 might be a potential therapeutic target for relieving PF progression.

Long non-coding RNA nuclear enriched abundant transcript 1 (NEAT1) modulates inhibitor of DNA binding 1 (ID1) to facilitate papillary thyroid carcinoma development by sponging microRNA-524-5p

Long non-coding RNA (lncRNA) nuclear-enriched abundant transcript 1 (NEAT1) exerts a pro-oncogenic role in several cancers, whereas its underlying regulatory mechanism in papillary thyroid carcinoma (PTC) progression remains unknown. This research mainly explored the roles of NEAT1 in PTC development. Quantitative real-time polymerase-chain reaction (qRT-PCR) was applied to measure NEAT1, miR-524-5p, and inhibitor of DNA binding 1 (ID1) expression in PTC tissues and cells. Western blot was conducted for detecting the protein levels. MTT, transwell, and flow cytometry assays were applied to assess cell proliferation, metastasis, and apoptosis in PTC cells in vitro. The PTC xenograft tumor model was used for investigating the role of NEAT1 in vivo. Dual-luciferase reporter assay was utilized for confirming the interaction between miR-524-5p and NEAT1 or ID1. In PTC tissues and cells, NEAT1 was significantly up-regulated. NEAT1 silencing blocked cell proliferation, metastasis, and facilitated apoptosis in vitro and impeded xenograft tumor growth in vivo. Bioinformatics prediction revealed the existence of binding sites between NEAT1 and miR-524-5p. Besides, ID1 was confirmed as a direct target to miR-524-5p, and the enhancement of ID1 reversed the regulation of miR-524-5p upregulation on cell progression. In addition, NEAT1 promoted PTC development by regulating ID1 expression via sponging miR-524-5p in PTC. In summary, we demonstrate that NEAT1 advanced the process of PTC by miR-524-5p/ID1 axis, which may enhance our comprehension of PTC pathogenesis.

LncRNA NEAT1 stabilized Wnt3a via U2AF2 and activated Wnt/β-catenin pathway to alleviate ischemia stroke induced injury

BACKGROUND

Ischaemic stroke is the leading cause of mortality and disability in the world. LncRNA NEAT1 has been shown to play an important role in ischaemic injury, but the molecular mechanism remains unclear.

METHODS

qRT-PCR was used to determine the expression of lncRNA NEAT1 in OGD/R-induced BV-2 cells. Cell viability was assessed by an MTT assay, and cell apoptosis was assessed by flow cytometry. The expression of related proteins was evaluated by Western blotting and ELISA. The interactions among lncRNA NEAT1, U2AF2 and Wnt3a mRNA was demonstrated by RIP and RNA pulldown assays. XAV-939 was used as an inhibitor of the Wnt/β-catenin pathway.

RESULTS

LncRNA NEAT1 was found to be downregulated in OGD/R-induced BV-2 cells. Overexpression of lncRNA NEAT1 protected BV-2 cells against OGD/R-induced injury. LncRNA NEAT1 enhanced the stability of Wnt3a mRNA via U2AF2. Knockdown of Wnt3a or blockade of the Wnt/β-catenin pathway rescued the effect of lncRNA NEAT1.

CONCLUSIONS

LncRNA NEAT1 protected cells against OGD/R-induced apoptosis and the inflammatory response by activating the Wnt/β-catenin pathway through upregulation of Wnt3a in a U2AF2-dependent manner. LncRNA NEAT1 could be a promising therapeutic candidate for ischaemic stroke treatment in the future.

Silencing lncRNA NEAT1 reduces nonalcoholic fatty liver fat deposition by regulating the miR-139-5p/c-Jun/SREBP-1c pathway

INTRODUCTION AND OBJECTIVES

Nonalcoholic fatty liver disease (NAFLD) starts with the abnormal accumulation of lipids in the liver. Long noncoding RNA (lncRNA) nuclear enriched abundant transcript 1 (NEAT1) was reported to modulate hepatic metabolic homeostasis in NAFLD. However, little is known about the molecular mechanisms of NAFLD.

MATERIALS AND METHODS

To establish a NAFLD cellular model, HepG2 cells and LO2 cells were treated with 1 mM free fatty acids (FFAs) for 24 h. NEAT1, miRNA (miR)-139-5p, c-Jun and sterol-regulatory element binding protein-1c (SREBP-1c) were evaluated using qPCR. The protein levels of c-Jun, SREBP1c, acetyl-CoA carboxylase (ACC) and fatty acid synthetase (FAS) were determined using western blotting. Moreover, Oil Red O staining was employed to assess lipid accumulation. In addition, a kit assay was performed to evaluate TG levels. Finally, the interactions among NEAT1, miR-139-5p, c-Jun and SREBP1c were identified by dual luciferase reporter gene assay.

RESULTS

NEAT1, c-Jun and SREBP1c expression was markedly elevated, while miR-139-5p expression was reduced in the NAFLD cellular model. NEAT1 knockdown restrained lipid accumulation in the NAFLD cellular model by directly targeting miR-139-5p. Moreover, miR-139-5p overexpression suppressed lipid accumulation by directly suppressing c-Jun expression. In addition, c-Jun silencing suppressed lipid accumulation by directly targeting SREBP1c. Finally, miR-139-5p inhibition mitigated the inhibitory effect of sh-NEAT1 on lipid accumulation.

CONCLUSION

NEAT1 aggravated FFA-induced lipid accumulation in hepatocytes by regulating the c-Jun/SREBP1c axis by sponging miR-139-5p, indicating the potential of NEAT1 as a promising therapeutic target for NAFLD.

The correlation between lncRNA NEAT1 and serum hepcidin in the peripheral blood of non-alcoholic fatty liver disease patients

OBJECTIVES

To explore and analyze the correlation between lncRNA NEAT1 and serum hepcidin (HEPC) in the peripheral blood of non-alcoholic fatty liver disease patients.

METHODS

119 patients, confirmed to have non-alcoholic fatty liver disease (NAFLD) and admitted to our hospital from January 2017 to June 2019, were enrolled in the NAFLD group, and 100 healthy subjects during the same period were enrolled in the control group. We recorded the two groups' general information and routine laboratory examination results and performed correlation analyses on the lncRNA NEAT1 expressions in their peripheral blood mononuclear cells (PBMCs) and HEPC.

RESULTS

The BMI, the waist circumferences, and the ALT, GGT, TC, and TG levels in the NAFLD group were critically higher than they were in the control group (P<0.05). The relative expressions of lncRNA NEAT1 in the PBMCs of the NAFLD group were remarkably higher than they were in the control group (P<0.05). The HEPC levels in the NAFLD group were significantly higher than they were in the control group (P<0.05). The lncRNA NEAT1 expressions in the NAFLD patients presented a remarkable positive correlation with the ALT, GGT, TC, and TG levels (P<0.05). The HEPC levels were positively correlated with the ALT, GGT, TC, and TG levels in the NAFLD patients (P<0.05), and the lncRNA NEAT1 expressions in the peripheral blood had a positive correlation with HEPC (P<0.05). We used ROC curves to analyze the diagnostic value of lncRNA NEAT1 in the peripheral blood to NAFLD, and the area under the curve was 0.822 (95% confidence interval of overall probability: 0.612~0.921). The sensitivity was 86.47%, and the specificity was 82.03%.

CONCLUSION

lncRNA NEAT1 is abnormally overexpressed in the PBMCs of patients with NAFLD. The regulatory effect of lncRNA NEAT1 on NAFLD may be related to the mechanism of HEPC, which is expected to be a potential biological indicator for the prevention and treatment of NAFLD.

Inhibition of lncRNA NEAT1 sensitizes medulloblastoma cells to cisplatin through modulating the miR-23a-3p-glutaminase (GLS) axis

Medulloblastoma (MB) is a commonly occurring brain malignancy in adolescence. Currently, the combination of chemotherapy with subsequent irradiation is a regular therapeutic strategy. However, high dosage of chemotherapy is associated with drug resistance and side effects. The long non-coding RNA nuclear paraspeckle assembly transcript 1 (NEAT1), which is frequently overexpressed in diverse human tumors, is correlated with worse survival rate in cancer patients. Currently, the precise roles of NEAT1 in MB and chemoresistance remain unclear. Our study aimed to investigate the biological functions of NEAT1 in cisplatin-resistant medulloblastoma. We report that NEAT1 was significantly upregulated in medulloblastoma patient specimens. Silencing NEAT1 significantly suppressed MB cell proliferation and sensitized MB cells to cisplatin. In cisplatin-resistant MB cell line, DAOY Cis R, NEAT1 expression, and glutamine metabolism were remarkably upregulated in cisplatin-resistant cells. Under low glutamine supply, cisplatin-resistant cells displayed increased cisplatin sensitivity. Bioinformatical analysis and luciferase assay uncovered that NEAT1 functions as a ceRNA of miR-23a-3p to downregulate its expressions in MB cells. Moreover, miR-23a-3p was apparently downregulated in MB patient tissues and cisplatin resistant MB cells. We identified GLS (glutaminase), a glutamine metabolism enzyme, was directly targeted by miR-23a-3p in MB cells. Rescue experiments demonstrated restoration of miR-23a-3p in NEAT1-overexpressing DAOY cisplatin resistant cells successfully overcame the NEAT1-promoted cisplatin resistance by targeting GLS. In general, our results revealed new molecular mechanisms for the lncRNA-NEAT1-mediated cisplatin sensitivity of MB.

PTRF/Cavin-1 as a Novel RNA-Binding Protein Expedites the NF-κB/PD-L1 Axis by Stabilizing lncRNA NEAT1, Contributing to Tumorigenesis and Immune Evasion in Glioblastoma

Background

Immunotherapy, especially checkpoint inhibitors targeting PD-1 or PD-L1, has revolutionized cancer therapy. However, PD-1/PD-L1 inhibitors have not been investigated thoroughly in glioblastoma (GBM). Studies have shown that polymerase 1 and transcript release factor (PTRF/Cavin-1) has an immune-suppressive function in GBM. Thus, the relationship between PTRF and PD-L1 and their role in immune suppression requires further investigation in GBM.

Methods

We used public databases and bioinformatics analysis to investigate the relationship between PTRF and PD-L1. We next confirmed the predicted relationship between PTRF and PD-L1 in primary GBM cell lines by using different experimental approaches. RIP-Seq, RIP, ChIP, and qRT-PCR were conducted to explore the molecular mechanism of PTRF in immunosuppression.

Results

We found that PTRF stabilizes lncRNA NEAT1 to induce NF-κB and PD-L1 and promotes immune evasion in GBM. PTRF was found to correlate with immunosuppression in the public GBM databases. PTRF increased the level of PD-L1 in primary cell lines from GBM patients. We carried out RIP-Seq of GBM cells and found that PTRF interacts with lncRNA NEAT1 and stabilizes its mRNA. PTRF also promoted the activity of NF-κB by suppressing UBXN1 expression via NEAT1 and enhanced the transcription of PD-L1 through NF-κB activation. Finally, PTRF promoted immune evasion in GBM cells by regulating PD-1 binding and PD-L1 mediated T cell cytotoxicity.

Conclusions

In summary, our study identified the PTRF-NEAT1-PD-L1 axis as a novel immune therapeutic target in GBM.

ALKBH5 promotes the progression of infantile hemangioma through regulating the NEAT1/miR-378b/FOSL1 axis

Our work aims to investigate long non-coding RNA (lncRNA) N6-methyladenosine (m⁶A) modification and its role in infantile hemangioma (IH). The mRNA and protein expression levels were assessed using quantitative real-time polymerase chain reaction, western blot and immunohistochemistry. Me-RIP assay was performed to evaluate lncRNA NEAT1 m⁶A levels. Cell proliferation, migration and invasion were evaluated using cell counting kit-8 assay, transwell migration and invasion assay, respectively. Photo-activatable ribonucleoside-enhanced crosslinking and immunoprecipitation assay was conducted to verify the binding relationship between lncRNA nuclear paraspeckle assembly transcript 1 (NEAT1) and ALKBH5 (an RNA demethylase). The binding relationship between lncRNA NEAT1, microRNA (miR)-378b and FOS-like antigen 1 (FOSL1) was verified using dual-luciferase reporter gene assay and/or RNA immunoprecipitation assay. ALKBH5, lncRNA NEAT1 and FOLS1 expression was elevated in IH tissues, while miR-378b was downregulated. ALKBH5 knockdown suppressed cell proliferation, migration and invasion of IH cells, while promoting cell apoptosis. ALKBH5 promoted lncRNA NEAT1 expression by reducing the m⁶A modification of lncRNA NEAT1. In addition, miR-378b was the target of lncRNA NEAT1, and its overexpression reversed the promotion effect of lncRNA NEAT1 overexpression on IH cell tumor-like behaviors. Moreover, FOLS1 was the target of miR-378b, and its overexpression reversed the inhibitory effect of miR-378b overexpression on IH cell tumor-like behaviors in vitro. ALKBH5 might have great potential as therapeutic target for IH, since ALKBH5 silencing suppressed IH progression by regulation of the NEAT1/miR-378b/FOSL1 axis.

Downregulation of lncRNA NEAT1 inhibits the proliferation of human cutaneous squamous cell carcinoma in vivo and in vitro

Background

The incidence of cutaneous squamous cell carcinoma (CSCC), a malignant tumor that threatens human life, is increasing every year, and yet its pathogenesis is still unclear. This study found that long noncoding RNA (lncRNA) nuclear-enriched abundant transcript 1 (NEAT1) was abnormally expressed in CSCC. However, the biochemical mechanisms of lncRNA NEAT1 in carcinogenesis and the development of cancer remain unclear.

Methods

Fluorescence quantitative polymerase chain reaction (qPCR) was conducted to determine lncRNA NEAT1 expression in CSCC and paracarcinoma tissues and investigate the correlation between NEAT1 levels and patients’ clinicopathological features. The invasion, proliferation, and migration of CSCC cells were measured using colony formation, Cell Counting Kit-8, and Transwell assays. Western blot assay was conducted to test whether NEAT1 knockdown affected invasion and migration-related proteins. In addition, a nude mouse subcutaneous tumorigenesis experiment was performed to determine whether the knockdown of NEAT1 affected the proliferation ability of CSCC cells.

Results

Changes in lncRNA NEAT1 expression in CSCC tissues were correlated with the degree of lymph node metastasis and the tumor, regional lymph nodes, and distant metastasis (TNM) grade of patients. The downregulation of NEAT1 lncRNA significantly impeded cell invasion, proliferation, and migration in CSCC. Through lncRNA NEAT1 knockdown, significant reductions in metalloproteinase-2, metalloproteinase-9, N-cadherin, and vimentin expression were observed, and the level of E-cadherin increased. In vivo experiments in nude mice revealed that knockdown of lncRNA NEAT1 greatly inhibited cell proliferation in CSCC.

Conclusions

In CSCC tissues, NEAT1 lncRNA was expressed at high levels and correlated with lymph node metastasis and TNM stage. The knockdown of NEAT1 lncRNA could significantly impede CSCC proliferation, metastasis, and invasion. Additionally, by measuring the expression level of lncRNA NEAT1, we may be able to detect the clinical and pathological characteristics of CSCC.

Substrate Stiffness Drives Epithelial to Mesenchymal Transition and Proliferation through the NEAT1-Wnt/β-Catenin Pathway in Liver Cancer

Background: Extracellular matrix (ECM)-derived mechanical stimuli regulate many cellular processes and phenotypes through mechanotransduction signaling pathways. Substrate stiffness changes cell phenotypes and promotes angiogenesis, epithelial to mesenchymal transition (EMT), and metastasis in tumors. Enhanced liver tissue matrix stiffness plays a crucial role in the tumorigenesis and malignant development of liver cancer and is associated with unfavorable survival outcomes. However, how liver cancer cells sense changes in ECM stiffness and the underlying molecular mechanisms are largely unknown. Methods: Seeding HepG2 cells on the micropillar gels, HepG2 cells were assessed for responsiveness to mechanotransduction using Western blot and immunofluorescence. Conclusions: We found that higher substrate stiffness dramatically enhanced malignant cell phenotypes and promoted G1/S transition in HepG2 cells. Furthermore, nuclear paraspeckle assembly transcript 1 (NEAT1) was identified as a matrix stiffness-responsive long non-coding RNA (lncRNA) regulating proliferation and EMT in response to increasing matrix stiffness during the progression of HepG2 cells towards liver cancer phenotypes. Higher matrix stiffness contributed to enhancing NEAT1 expression, which activated the WNT/β-catenin pathway. β-catenin translocates and enters the nucleus and the EMT transcription factor zinc finger E-box binding homeobox 1 (ZEB1) was upregulated to trigger EMT. Additionally, the proteins required for matrix stiffness-induced proliferation and resistance were strikingly upregulated in HepG2 cells. Therefore, our findings provide evidence that ECM-derived mechanical signals regulate cell proliferation and drive EMT through a NEAT1/WNT/β-catenin mechanotransduction pathway in the tumor microenvironment of liver cancer.

Long non-coding RNA NEAT1 and its targets (microRNA-21 and microRNA-125a) in rheumatoid arthritis: Altered expression and potential to monitor disease activity and treatment outcome

Background

The present study aimed to explore the association of long non‐coding RNA nuclear‐enriched abundant transcript 1 (lnc‐NEAT1) with inflammation, disease activity, treatment outcome, and its targets (microRNA [miR]‐21 and miR‐125a) in patients with rheumatoid arthritis (RA).

Methods

Peripheral blood mononuclear cells were sampled from 130 RA patients at baseline, week (W) 6, and W12, as well as from 60 healthy controls (HCs) after enrollment. Meanwhile, the expressions of lnc‐NEAT1, miR‐21, and miR‐125a were detected by reverse transcription‐quantitative polymerase chain reaction.

Results

lnc‐NEAT1 was elevated, but miR‐21 and miR‐125a were declined in RA patients compared with HCs (all p < 0.001); meanwhile, lnc‐NEAT1 was negatively correlated with miR‐21 and miR‐125a (both p < 0.05) in RA patients. Besides, elevated lnc‐NEAT1 but declined miR‐21 and miR‐125a were correlated with erythrocyte sedimentation rate (ESR) and C‐reactive protein and the 28‐joint Disease Activity‐ESR score (all p < 0.05) in RA patients. Moreover, lnc‐NEAT1 was declined from baseline to W12 in RA patients (p < 0.001). Additionally, lnc‐NEAT1 at W12 was declined in response patients compared with non‐response patients (p = 0.006), and also decreased in remission patients compared with non‐remission patients (p < 0.001).

Conclusion

lnc‐NEAT1 and its targets (miR‐21 and miR‐125a) correlate with RA risk and disease activity, and declined lnc‐NEAT1 associates with better treatment outcome to some extent in RA patients, suggesting that lnc‐NEAT1 might be a potential biomarker to monitor disease activity and treatment outcome in RA.

Acetylation of H3K27 activated lncRNA NEAT1 and promoted hepatic lipid accumulation in non-alcoholic fatty liver disease via regulating miR-212-5p/GRIA3

Non-alcoholic fatty liver disease (NAFLD) was a world-wide health burden. H3K27 acetylation, long non-coding RNA (lncRNA), and miRNA were all implicated in NAFLD regulation, yet the detailed regulatory mechanism was not well understood. LncRNA NEAT1, miR-212-5p, and GRIA3 expression were detected both in high fatty acid-treated hepatocytes cells and NAFLD patients. Lipid droplets were stained and analyzed by oil red O staining. Expression of fatty acid synthase (FASN), acetyl-CoA carboxylase (ACC), and GRIA3 was detected by qRT-PCR and western blot. RNA level of lncRNA NEAT1 and miR-212-5p was analyzed by qRT-PCR. The binding sequences of lncRNA NEAT1/miR-212-5p and miR-212-5p/GRIA3 were predicted bioinformatically and validated through luciferase assay. ChIP was performed to analyze H3K27 acetylation on the promoter of lncRNA NEAT1. LncRNA NEAT1 and GRIA3 was upregulated, while miR-212-5p was downregulated in NAFLD patients. FFA promoted lncRNA NEAT1 and GRIA3 expression while suppressing miR-212-5p and promoted lipid accumulation as indicated by increased oil red O staining and FAS and ACC expression. ChIP indicated enrichment of H3K27 on NEAT1 promoter. Inhibition of H3K27 acetylation suppressed lncRNA NEAT1 level. Luciferase results indicated direct interaction of NEAT1/miR-212-5p (which was confirmed by RIP) and miR-212-5p/GRIA3. LncRNA NEAT1 knockdown upregulated miR-212-5p level and inhibited FFA-induced lipid accumulation while suppressing GRIA3 expression. Such function was antagonized by miR-212-5p inhibition and GRIA3 knockdown counteracted with miR-212-5p inhibition. H3K27 acetylation was enriched within the promoter of lncRNA NEAT1 and promoted lncRNA NEAT1 transcription. LncRNA NEAT1 could then interact with miR-212-5p and suppress its cellular concentration.

lncRNA NEAT1 regulates CYP1A2 and influences steroid-induced necrosis

The main cause of steroid-induced necrosis of femoral head (SNFH) is excessive glucocorticoid (GC) intake. The aim of this article was to investigate the role of lncRNA NEAT1 as a molecular sponge to adsorb miR-23b-3p and regulate CYP1A2 in SNFH. Fluorescence in situ hybridization was used to localize lncRNA NEAT1. Human bone marrow mesenchymal stem cells (hBMSCs) were collected from patients with SNFH. The expression of lncRNA NEAT1, miR-23b-3p and CYP1A2 in hBMSCs were intervened. Compared to the control group, the lncRNA NEAT1 and CYP1A2 expression in the SNFH group was increased, while miR-23b-3p expression was decreased. GCs could inhibit the osteogenic differentiation of hBMSCs and upregulate the expression of lncRNA NEAT1. Knockdown of lncRNA NEAT1 could promote the proliferation and osteogenic differentiation of hBMSCs in the SNFH group. Overexpression of miR-23b-3p could partially counteract the effect of lncRNA NEAT1 on hBMSCs. CYP1A2 was confirmed to be a target of miR-23b-3p. Overexpression of CYP1A2 could partially rescue the effect of miR-23b-3p overexpression on hBMSCs. In conclusion, lncRNA NEAT1 as a ceRNA can adsorb miR-23b-3p and promote the expression of CYP1A2, which then inhibits the osteogenic differentiation of hBMSCs and promotes the progress of SNFH.

lncRNA NEAT1 promotes the Taxol resistance of breast cancer via sponging the miR-23a-3p-FOXA1 axis

Breast cancer is the most prevalent malignancy among women worldwide. Paclitaxel (Taxol) is a widely applied chemotherapeutic agent against breast cancer. Although Taxol therapy has achieved improvements recently, development of chemoresistance of breast cancer patients is a major obstacle, leading to therapeutic failure. Long non-coding RNAs (lncRNAs) play pivotal roles in tumorigenesis and progresses of breast cancer. However, the biological roles and molecular targets of lncRNA NEAT1 in Taxol-resistant breast cancer remain unclear. Here, we report that NEAT1 is significantly upregulated in breast tumors and cell lines. In addition, silencing NEAT1 effectively sensitizes breast cancer cells to Taxol. Bioinformatical analysis and luciferase assay demonstrated that miR-23a-3p could be sponged and downregulated by NEAT1. We demonstrated that miR-23a-3p was downregulated and functioned as a tumor suppressor in breast cancer. Furthermore, in the established Taxol-resistant MDA-MB-231 breast cancer cell line, we detected significantly increased NEAT1 expression and downregulated miR-23a-3p expression. Importantly, FOXA1 was identified and validated as a direct target of miR-23a-3p in breast cancer cells. Rescue experiments demonstrated that the restoration of miR-23a-3p in NEAT1-overexpressing Taxol-resistant breast cancer cells successfully overcame the NEAT1-promoted Taxol resistance. Taken together, our results revealed the clinical roles and molecular mechanisms for the NEAT1-mediated chemoresistance, providing new insights into the development of non-coding RNA-based therapeutic strategies for enhancing the anti-cancer effects of traditional chemotherapeutic drugs.

LncRNA NEAT1 regulates MMP-16 by targeting miR-200a/b to aggravate inflammation in asthma

Asthma is a common respiratory disease which is characterized by persistent airway inflammation. Abnormal expression of long non-coding RNAs (lncRNAs) is observed in asthma. However, whether lncRNA nuclear-enriched abundant transcript 1 (NEAT1) regulates asthmatic inflammation and its mechanism still needs to be further investigated. The expression levels of inflammatory factors (tumour necrosis factor (TNF)-α, interleukin (IL)-4, IL-13, and IL-10) were detected using reverse transcription quantitative real-time PCR (RT-qPCR) and enzyme-linked immunosorbent assay (ELISA). MTT and flow cytometry assays were employed to determine cell proliferation and apoptosis, respectively. Dual luciferase reporter assay was performed to verify the relationship between miR-200a/b and MMP-16 or NEAT1. NEAT1 silencing markedly reduced TNF-α, IL-4, and IL-13 levels, while elevated IL-10 expression, suppressed cell proliferation, and promoted cell apoptosis. However, NEAT1 overexpression elicited the opposite effects on cell proliferation and inflammation cytokines secretion. What is more, NEAT1 negatively regulated miR-200a/b expression, and MMP16 was a target gene of miR-200a/b. miR-200a/b overexpression suppressed inflammation, cell proliferation, and enhanced cell apoptosis through regulation of MMP16. Moreover, MMP-16 overexpression or miR-200a/b inhibition abolished the regulatory effect of sh-NEAT1 on cell inflammation and apoptosis in BEAS-2B cells. NEAT1 acted as the role of sponge for miR-200a/b to regulate MMP-16 expression, thereby promoting asthma progression, suggesting that NEAT1 might have great potential as therapeutic target for asthma.

Long non-coding RNA (lncRNA) nuclear enriched abundant transcript 1 (NEAT1) regulates fibroblast growth factor receptor substrate 2 (FRS2) by targeting microRNA (miR)-29-3p in hypertrophic scar fibroblasts

Long non-coding RNAs (lncRNAs) play crucial roles in human diseases. However, the detailed role of lncRNAs in hypertrophic scar fibroblasts (HSFs) is inadequately understood. This study aimed to investigate the potential role of lncRNA nuclear enriched abundant transcript 1 (NEAT1) in hypertrophic scarring. Expression of lncRNAs, miRNAs, and genes were detected by polymerase chain reaction; protein expression was evaluated using western blotting. Cellular function was determined using the CCK-8 assay. The interaction between microRNA (miR)-29-3p and NEAT1 or fibroblast growth factor receptor substrate 2 (FRS2) was verified by luciferase and RNA pull-down assays. The results showed that NEAT1 was overexpressed in the hypertrophic dermis and in HSFs. However, knockdown of NEAT1 suppressed the proliferation and extracellular matrix (ECM) production of HSFs. Moreover, NEAT1 functioned as a competing endogenous RNA to upregulate FRS2 by sponging miR-29-3p. Downregulation of miR-29-3p or overexpression of FRS2 antagonized the effects of NEAT1 knockdown and promoted HSF proliferation and ECM release. In conclusion, NEAT1 knockdown protected against hypertrophic scarring by modulating the miR-29-3p/FRS2 axis, which is a viable target in scar treatment.

LncRNA NEAT1 correlates with Th1 and Th17 and could serve as an assistant biomarker in sepsis

Aim: Investigating correlation of lncRNA NEAT1 with Th1 and Th17 in sepsis, and their associations with inflammation, disease severity and prognosis. Materials & methods: A total of 127 sepsis patients and 50 health subjects were included. LncRNA NEAT1, Th1, Th17 and Th1/Th17-secreted cytokines were detected. Results: LncRNA NEAT1 positively correlated with Th1 and Th17 cell proportions in sepsis patients. LncRNA NEAT1 positively correlated with Th1 and Th17-secreted cytokine levels in sepsis patients. LncRNA NEAT1 and Th17 cell proportion positively correlated with CRP level, acute physiology and chronic health evaluation II score and sequential organ failure assessment score. High lncRNA NEAT1 expression, Th1 and Th17 cell proportions correlated with elevated accumulating mortality. Conclusion: LncRNA NEAT1 positively correlated with Th1 and Th17, and may serve as an assistant biomarker in sepsis patients.

LncRNA NEAT1 promotes Alzheimer's disease by down regulating micro-27a-3p

OBJECTIVE

Alzheimer's disease (AD) is a common neurodegenerative disease. This study was designed to investigate the roles of lncRNA NEAT1/miR-27a-3p axis in AD.

METHODS

Amyloid protein was used to treat SH-SY5Y cells and rats to construct AD model. RT-qPCR was used to quantify lncRNA NEAT1 and micro-27a-3p in AD model cells. Western blot was used to determine the β-amyloid-precursor-protein-cleaver-enzyme 1 (BACE1), amyloid, Tau protein and its phosphorylation, Caspase 3 protein and its lytic cell protein and amyloid precursor protein (APP). Flow cytometry was used to detect apoptosis. The cell activity was detected by CCK-8. The lncRNA NEAT1 and miR-27a-3p inhibition or over-expression vectors were constructed. The dual luciferase reporter gene and RNA pull-down assay were used to detect the targeting relationship between lncRNA NEAT1 and micro-27a-3p. The cognitive function of rats was tested by water maze.

RESULTS

After being induced by amyloid protein, lncRNA NEAT1 was up-regulated while micro-27a-3p was down-regulated in SH-SY5Y cells. Apoptosis rate was increased and cell activity was decreased. Amyloid protein, BACE1 protein, APP protein, Tau protein and its phosphorylation, Caspase 3 protein and its lytic cell protein were up-regulated. Down-regulation of lncRNA NEAT1 or up-regulation of micro-27a-3p could reduce cell apoptosis, increase cell activity, down-regulate amyloid protein, BACE1 protein, APP protein, Tau protein and its phosphorylation, and up-regulate caspase 3 protein and its lysate protein. Dual luciferase reporter gene assay and RNA pull-down experiments revealed that micro-27a-3p was the target gene of lncRNA NEAT1. Down-regulation of micro-27a-3p could offset the changes caused by LncRNA NEAT1. AD caused cognitive dysfunction in rats, which was improved by down-regulation of lncRNA NEAT1.

CONCLUSION

lncRNA NEAT1 regulates the development of AD by down-regulating micro-27a-3p.

Baicalin enhances the proliferation and invasion of trophoblasts and suppresses vascular endothelial damage by modulating long non-coding RNA NEAT1/miRNA-205-5p in hypertensive disorder complicating pregnancy

AIM

Trophoblastic and vascular endothelial injuries were closely associated with the pathogenesis of hypertensive disorder complicating pregnancy (HDCP). The present study was designed to determine the functional role of baicalin in the proliferation and invasion of trophoblasts and vascular endothelial injury.

METHODS

Ang II was adopted to stimulate HTR-8/SVneo and human umbilical vein endothelial cells (HUVECs). Cell viability was examined by CCK-8 assay. Flow cytometry and TUNEL staining determined cell apoptosis. Invasive ability of HTR-8/SVneo cells was measured by transwell assay. In vitro angiogenesis of HUVECs was assessed by Tube formation assay. In addition, the production of reactive oxygen species (ROS) was determined by DCFH-DA staining. Furthermore, long non-coding RNA (lncRNA) NEAT1 and miRNA-205-5p levels were detected using real-time quantitative polymerase chain reaction and the binding relationship between lncRNA NEAT1 and miRNA-205-5p was verified by dual-luciferase reporter assay. Moreover, interactions among lncRNA NEAT1, miRNA-205-5p, and MMP9 or vascular endothelial growth factor (VEGF) were confirmed by RNA immunoprecipitation assay.

RESULTS

Baicalin visibly improved cell viability, reduced the apoptosis of Ang II-stimulated HTR-8/SVneo and HUVEC cells, and repressed overproduction of ROS. Additionally, baicalin promoted the invasion of Ang II-stimulated HTR-8/SVneo cells and induced a stronger in vitro angiogenesis of Ang II-stimulated HUVECs. What's more, baicalin upregulated lncRNA NEAT1 expression and downregulated miR-205-5p expression. LncRNA NEAT1 sponged miR-205-5p and inhibited the combination of miR-205-5p and MMP9 or VEGF.

CONCLUSIONS

Baicalin can facilitate the proliferation and invasion of trophoblasts and alleviate vascular endothelial damage by upregulating lncRNA NEAT1 to impede the interaction between miR-205-5p and MMP9 or VEGF.

LncRNA GAS8-AS1 downregulates lncRNA NEAT1 to inhibit glioblastoma cell proliferation

BACKGROUND

LncRNA GAS8-AS1 has been reported to participate in several types of cancer, while its role in glioblastoma (GBM) is unknown. In the present study, we aimed to investigate the function of GAS8-AS1 in GBM and the underlying mechanisms.

METHODS

The expression levels of GAS8-AS1 and NEAT1 in GBM patients and the healthy controls were measured by performing RT-qPCR. Diagnostic values of plasma GAS8-AS1 and NEAT1 for GBM were analyzed by performing ROC curve analysis with GBM patients as true positive cases and the healthy controls as true negative cases. Linear regression analysis was performed to study the correlation between the expression levels of GAS8-AS1 and NEAT1. The expression levels of GAS8-AS1 and NEAT1 in GBM cells were also determined by RT-qPCR. CCK-8 and transwell invasion assays were performed to detect the proliferation and invasion of GBM cells. Western blot assay was performed to detect the expression levels of β-catenin, Axin2, c-myc, cyclin D1, and GAPDH in GBM cells.

RESULTS

GAS8-AS1 was downregulated, while lncRNA NEAT1 was upregulated in the plasma of GBM patients. Altered expression levels of GAS8-AS1 and NEAT1 distinguished GBM patients from the healthy controls. The expression of GAS8-AS1 and NEAT1 was inversely correlated only in GBM patients. Overexpression of GAS8-AS1 reduced the expression levels of NEAT1 in GBM cells, while knock-down of GAS8-AS1 increased the expression levels of NEAT1. However, overexpression of NEAT1 showed no significant effects on the expression of GAS8-AS1. Knock-down of GAS8-AS1 promoted GBM cell proliferation and invasion and enhanced the activation of the Wnt/β-catenin pathway. However, the effects of knock-down of GAS8-AS1 were alleviated by the knock-down of NEAT1.

CONCLUSION

Overexpression of GAS8-AS1 inhibits GBM cell proliferation and invasion by downregulating NEAT1.

Long Noncoding RNA NEAT1: A Potential Biomarker in the Progression of Laryngeal Squamous Cell Carcinoma

INTRODUCTION

Laryngeal squamous cell carcinoma (LSCC) is diverse in its natural history and responsiveness to treatments. There is an urgent need to generate candidate biomarkers for the stratification and individualization of treatment to avoid overtreatment or inadequate treatment. Long noncoding RNA nuclear paraspeckle assembly transcript 1 (NEAT1) has been identified as an oncogenic gene in multiple human tumors entitles, and dysregulation of NEAT1 was tightly linked to carcinogenesis and cancer progression.

METHODS

One hundred two paraffin samples of LSCC patients were collected. Furthermore, in situ hybridization (ISH), Kaplan-Meier, and MTT were used to analyze the relationship between NEAT1 and the progress of LSCC.

RESULTS

In this study, ISH revealed that NEAT1 was strongly expressed in the nucleus. The increased expression of NEAT1 was correlated with T grade, neck nodal metastasis, clinical stage, drinking history, or smoking history of LSCC. The Kaplan-Meier analysis indicated that patients with higher NEAT1 expression had a worse overall survival in LSCC patients. In addition, NEAT1 knockdown significantly inhibited the growth of LSCC cells.

CONCLUSION

Together, these results suggested that NEAT1 involved in the progress of LSCC and might act as a tumor oncogenic gene. This study provides a potential new marker and target for gene therapy in the treatment of LSCC.

LncRNA NEAT1 activates MyD88/NF-κB pathway in bronchopneumonia through targeting miR-155-5p

BACKGROUND

Bronchopneumonia is a disease of the respiratory tract. It leads to other complications and endangers life and health. Long non-coding RNA (lncRNA) participates in the occurrence and development of bronchopneumonia. Nuclear paraspeckle assembly transcript 1 (NEAT1) plays a key role in inflammatory diseases, but the function of NEAT1 in bronchopneumonia remains unclear.

METHODS

RT-qPCR and Western blotting were performed to determine genes and proteins expressions. MTT was applied to test cell viability. Cell apoptosis was detected by flow cytometry. RIP was used to investigate the correlation between NEAT1 and miR-155-5p. The interaction between miR-155-5p and NEAT1 or MyD88 was evaluated by the dual-luciferase reporter gene.

RESULTS

NEAT1 and MyD88 were upregulated in BEAS-2B cells by LPS, while miR-155-5p was downregulated. Knockdown of NEAT1 inhibited LPS-induced BEAS-2B cells growth inhibition by inhibiting the apoptosis. In addition, NEAT1 silencing suppressed LPS-induced inflammatory responses in BEAS-2B cells via suppression of TNF-α, IL-1β, IL-6, and IL-18. Meanwhile, NEAT1 is directly bound to miR-155-5p to regulate MyD88/NF-κB axis, and overexpression of miR-155-5p increased cell proliferation and suppressed inflammatory factors expression levels and cell apoptosis. Furthermore, sh-NEAT1-induced inhibition of BEAS-2B cells injury was partially reversed by miR-155-5p inhibitor or MyD88 overexpression.

CONCLUSION

NEAT1 silencing suppressed LPS-induced BEAS-2B cells injury and inflammation by the mediation of miR-155-5p/MyD88/NF-κB axis. Thus, our study might shed new light on exploring the new strategies for the treatment of bronchopneumonia.

Prognostic Value of lncRNA NEAT1 as a New Biomarker in Digestive System Tumors: a Systematic Study and Meta-analysis

OBJECTIVE

Nuclear paraspeckle assembly transcript 1 (NEAT1), a newly found lncRNA, is found abnormally expressed in digestive system tumors. This meta-analysis aims to evaluate the effect of NEAT1 on digestive system tumors.

METHODS

An analysis was conducted to investigate NEAT1 expression in digestive system tumors from the PubMed, Embase, and Web of Science databases. The relationship between NEAT1 expression and patient overall survival (OS) and clinicopathology was evaluated by correlation analysis with the pooled hazard ratio (HR), 95% confidence interval (CI), and odds ratio (OR).

RESULTS

A total of 12 published studies were enrolled in this meta-analysis. The NEAT1 overexpression was significantly associated with poor OS (HR = 1.64, 95% CI:1.41-1.91, p < 0.05), lymphatic metastasis (OR = 2.70, 95% CI: 2.02-3.61, p < 0.05), distal metastasis (OR = 3.01, 95% CI: 1.97-4.59, p < 0.05) and advanced tumor stage (OR = 3.04, 95% CI: 2.32-3.99, p < 0.05). However, digestive system tumor patients with high NEAT1 expression was not related to the patients' age (OR = 0.91, 95% CI: 0.65-1.26, p = 0.561), gender (OR = 1.04, 95% CI: 0.81-1.33, p = 0.761), tumor size (OR = 1.84, 95% CI: 0.88-3.88, p = 0.106), and tumor differentiation (OR = 0.86, 95% CI: 0.51-1.44, p = 0.570).

CONCLUSION

Collectively, NEAT1 can be used as a potential biomarker to predict the prognosis of patients with digestive system tumors, which is worth verifying in clinical practice.

LncRNA NEAT1 mediates progression of oral squamous cell carcinoma via VEGF-A and Notch signaling pathway

BACKGROUND

lncRNAs and VEGF have been shown to have close connections with oral squamous cell carcinoma (OSCC). We explored the interaction between lncRNA NEAT1 and VEGF-A in OSCC.

METHODS

RT-qPCR was implemented to measure levels of lncRNA NEAT1 and VEGF-A in OSCC cell lines and normal cell lines. Cell functions then were checked after regulating the expressions of lncRNA NEAT1 and VEGF-A separately. Cell viabilities were examined with CCK-8 and apoptosis rate was checked with flow cytometry. Meanwhile, EMT-related genes E-cadherin, N-cadherin, Vimentin, and Snail and Notch signaling genes Notch1, Notch2, and Jagged were evaluated by RT-qPCR. IMR-1 was applied for impeding Notch signaling pathway. Later, cell viabilities, apoptosis, and EMT were assessed.

RESULTS

Expressions of lncRNA NEAT1 and VEGF-A were both increased significantly in OSCC cell lines especially in TSCC1 cell line. Suppression of lncNRA NEAT1 was associated with lower cell viabilities and EMT and higher apoptosis rate in the TSCC1 cell line. Meanwhile, knockdown of VEGF-A significantly repressed cell viabilities and EMT in the TSCC1 cell line. Magnifying functions of inhibited lncRNA NEAT1 Notch signaling pathway was obviously activated with overexpressions of lncRNA NEAT1 and VEGF-A. Adding IMR-1 significantly downregulated cell viabilities and EMT and sharply increased apoptosis in the context of lncRNA NEAT1 and VEGF-A overexpression.

CONCLUSION

LncRNA NEAT1 may upregulate proliferation and EMT and repress apoptosis through activating VEGF-A and Notch signaling pathway in vitro, suggesting an underlying regulatory factor in OSCC. Nevertheless, further research is necessary to gain a greater understanding of lncRNA NEAT1 and connections with VEGF-A in vivo and in clinical study.

NEAT1/miR-140-3p/MAPK1 mediates the viability and survival of coronary endothelial cells and affects coronary atherosclerotic heart disease

Studies have shown that long non-coding RNAs (lncRNA) play critical roles in coronary atherosclerotic heart disease (CAD). However, the function of lncRNA nuclear enriched abundant transcript 1 (NEAT1) in CAD is unclear. In this study, we aimed to investigate the functions of lncRNA NEAT1 in CAD. RT-PCR and western blot analysis were carried out to examine the expressions of related RNAs. Colony formation assay, cell proliferation assay, apoptosis assay, and dual-luciferase reporter assay were conducted to investigate the abilities of colony migration, cell proliferation, apoptosis, and targeting. The results showed that NEAT1 was up-regulated in CAD blood samples and in human coronary endothelial cells (HCAECs). Transfection of pcNEAT1 significantly inhibited the survival rate of HCAECs and induced apoptosis of HCAECs. MiR-140-3p was down-regulated in HCAECs. NEAT1 directly targeted miR-140-3p, and the expression of miR-140-3p was inversely correlated with the expression of NEAT1 in CAD patients. In addition, co-transfection of NEAT1 with miR-140-3p mimic reversed the effect of pcNEAT1 on cell viability and apoptosis. mitogen-activated protein kinase 1 (MAPK1) was proved to be a target gene of miR-140-3p, and the miR-140-3p mimic was shown to reduce the expression of MAPK1 in HCAECs. pcNEAT1 significantly increased the expression level of MAPK1, while shNEAT1 significantly reduced the expression level of MAPK1. Our results revealed that lncRNA NEAT1 increased cell viability and inhibited CAD cell apoptosis possibly by activating the miR-140-3p/MAPK1 pathway, and lncRNA NEAT1 might serve as a potential therapeutic target for CAD.

Long Non-Coding RNA NEAT1 Promotes the Proliferation, Migration, and Metastasis of Human Breast-Cancer Cells by Inhibiting miR-146b-5p Expression

Background

Breast cancer (BC) is the most commonly diagnosed cancer in women. Tumor recurrence and metastasis are the key causes of death in BC patients. Long non-coding RNA (lncRNA) is closely associated with BC progression. lncRNA nuclear-enriched abundant transcript (NEAT)1 has been reported to regulate the proliferation and mobility of several types of cancer cells. However, how lncRNA NEAT1 affects the proliferation and invasion of BC cells is not known.

Methods

Quantitative real time-polymerase chain reaction (qRT-PCR) was used to measure expression of lncRNA NEAT1 and microRNA (miR)-146b-5p in BC tissues and cell lines. Cell Counting Kit (CCK)-8, cell colony-formation, wound-healing, and Transwell™ assays were undertaken to determine the effects of lncRNA NEAT1 and miR-146b-5p on progression of BC cells. The interaction between lncRNA NEAT1 and miR-146b-5p was examined by luciferase reporter, RNA-binding protein immunoprecipitation (RIP), and RNA-pulldown assays.

Results

Expression of lncRNA NEAT1 was upregulated in BC tissues and cell lines. High expression of lncRNA NEAT1 predicted poor overall survival in BC patients. Silencing of expression of lncRNA NEAT1 inhibited epithelial–mesenchymal transition (EMT) and suppressed the proliferation, migration and invasion of BC cells. Ectopic expression of lncRNA NEAT1 induced EMT and promoted BC progression. Mechanistic investigations revealed that miR-146b-5p was a direct target of lncRNA NEAT1, and its expression was correlated negatively with expression of lncRNA NEAT1 in BC tissues.

Conclusion

lncRNA NEAT1 could (i) serve as a novel prognostic marker for BC and (ii) be a potential therapeutic target for BC.

LncRNA NEAT1/miR-129/Bcl-2 signaling axis contributes to HDAC inhibitor tolerance in nasopharyngeal cancer

Histone deacetylase inhibitors (HDACis) - based therapeutic drug tolerance is one of the principal factors of poor prognosis of patients with nasopharyngeal cancer (NPC). Mechanisms of tolerance to HDACis are not well understood. Nowadays, dysregulation of long non-coding RNAs (LncRNAs) and microRNAs (miRNAs) has been reported to provide beneficial or inhibitory effects in drug-tolerance in various cancers. Herein, we established the HDAC inhibitor (SAHA)-tolerant NPC cell sublines, which had decreased apoptosis in response to SAHA treatment. We observed that the expression of miR-129 was significantly reduced in SAHA-tolerant NPC cells. Manipulating the expression of miR-129 overcame SAHA tolerance, and enhanced the SAHA-induced apoptosis. In terms of miR-129 downregulation, we identified that NEAT1 suppresses miR-129 expression. NEAT1 was found to be upregulated in SAHA tolerance cells. The depletion of NEAT1 phenocopied the effect of miR-129 overexpression, which also enhanced SAHA-induced apoptosis. Bcl-2 was the downstream target of miR-129 and contributed to SAHA tolerance in NPC. Our in vivo xenograft experiment confirmed that the administration of miR-129 or inhibition of Bcl-2 overcame the SAHA tolerance in NPC. In conclusion, NEAT1 increases in NPC tissues and manages to facilitate SAHA tolerance by modulating the miR-129/Bcl-2 axis, providing novel therapeutic targets for NPC treatment.

Stress Induces Dynamic, Cytotoxicity-Antagonizing TDP-43 Nuclear Bodies via Paraspeckle LncRNA NEAT1-Mediated Liquid-Liquid Phase Separation

Despite the prominent role of TDP-43 in neurodegeneration, its physiological and pathological functions are not fully understood. Here, we report an unexpected role of TDP-43 in the formation of dynamic, reversible, liquid droplet-like nuclear bodies (NBs) in response to stress. Formation of NBs alleviates TDP-43-mediated cytotoxicity in mammalian cells and fly neurons. Super-resolution microscopy reveals distinct functions of the two RRMs in TDP-43 NB formation. TDP-43 NBs are partially colocalized with nuclear paraspeckles, whose scaffolding lncRNA NEAT1 is dramatically upregulated in stressed neurons. Moreover, increase of NEAT1 promotes TDP-43 liquid-liquid phase separation (LLPS) in vitro. Finally, we discover that the ALS-associated mutation D169G impairs the NEAT1-mediated TDP-43 LLPS and NB assembly, causing excessive cytoplasmic translocation of TDP-43 to form stress granules, which become phosphorylated TDP-43 cytoplasmic foci upon prolonged stress. Together, our findings suggest a stress-mitigating role and mechanism of TDP-43 NBs, whose dysfunction may be involved in ALS pathogenesis.

Mir-370-3p Impairs Glioblastoma Stem-Like Cell Malignancy Regulating a Complex Interplay between HMGA2/HIF1A and the Oncogenic Long Non-Coding RNA (lncRNA) NEAT1

Glioblastoma (GBM) is the most aggressive and prevalent form of a human brain tumor in adults. Several data have demonstrated the implication of microRNAs (miRNAs) in tumorigenicity of GBM stem-like cells (GSCs). The regulatory functions of miRNAs in GSCs have emerged as potential therapeutic candidates for glioma treatment. The current study aimed at investigating the function of miR-370-3p in glioma progression, as aberrant expression of miR-370-3p, is involved in various human cancers, including glioma. Analyzing our collection of GBM samples and patient-derived GSC lines, we found the expression of miR-370-3p significantly downregulated compared to normal brain tissues and normal neural stem cells. Restoration of miR-370-3p expression in GSCs significantly decreased proliferation, migration, and clonogenic abilities of GSCs, in vitro, and tumor growth in vivo. Gene expression analysis performed on miR-370-3p transduced GSCs, identified several transcripts involved in Epithelial to Mesenchymal Transition (EMT), and Hypoxia signaling pathways. Among the genes downregulated by the restored expression of miR-370-3p, we found the EMT-inducer high-mobility group AT-hook 2 (HMGA2), the master transcriptional regulator of the adaptive response to hypoxia, Hypoxia-inducible factor (HIF)1A, and the long non-coding RNAs (lncRNAs) Nuclear Enriched Abundant Transcript (NEAT)1. NEAT1 acts as an oncogene in a series of human cancers including gliomas, where it is regulated by the Epidermal Growth Factor Receptor (EGFR) pathways, and contributes to tumor growth and invasion. Noteworthy, the expression levels of miR-370-3p and NEAT1 were inversely related in both GBM tumor specimens and GSCs, and a dual-luciferase reporter assay proved the direct binding between miR-370-3p and the lncRNAs NEAT1. Our results identify a critical role of miR-370-3p in the regulation of GBM development, indicating that miR-370-3p acts as a tumor-suppressor factor inhibiting glioma cell growth, migration and invasion by targeting the lncRNAs NEAT1, HMGA2, and HIF1A, thus, providing a potential candidate for GBM patient treatment.

Down-regulation of lncRNA NEAT1 regulated by miR-194-5p/DNMT3A facilitates acute myeloid leukemia

OBJECTIVE

miR-194-5p and NEAT1 have been reported to be associated with multiple malignancies, but their roles in acute myeloid leukemia (AML) remains not fully understood.

METHODS

Bone marrow samples were collected for monocyte separation. qRT-PCR assay was performed to investigate the expression patterns of NEAT1 and miR-194-5p in AML. CCK-8, soft agar colony formation, flow cytometry and transwell assays were employed to explore the biological functions of NEAT1 or miR-194-5p. Methylation PCR was performed to monitor the methylation of NEAT1. Luciferase reporter assay was subjected to verify the relationship between miR-194-5p and DNMT3A. Immunofluorescence and western blotting were performed to detect the alterations of protein expression.

RESULTS

NEAT1 and miR-194-5p were both down-regulated in AML. Overexpression of either NEAT1 or miR-194-5p repressed proliferation, induced apoptosis and restrained migration and invasion of AML cells. There was a negative correlation between NEAT1 and DNMT3A in AML. Knockdown of DNMT3A dramatically decreased the methylation of NEAT1. Moreover, DNMT3A was identified as a downstream target of miR-194-5p. Furthermore, down-regulation of DNMT3A rescued the impacts on the malignant phenotypes of NEAT1 inhibition by miR-194-5p inhibitor.

CONCLUSION

Altogether, down-regulation of NEAT1 mediated by miR-194-5p/DNMT3A axis promotes AML progression, which might provide therapeutic targets in AML treatment.

Suppression of long noncoding RNA NEAT1 attenuates hypoxia-induced cardiomyocytes injury by targeting miR-378a-3p

BACKGROUND/AIMS

lncRNA NEAT1 is involved in the development of many diseases. However, the function of lncRNA NEAT1 in myocardial infarction is unclear. Therefore, this experimental design based on lncRNA NEAT1 to explore the pathogenesis of myocardial infarction.

METHODS

RT-qPCR was used to detect the expression of lncRNA NEAT1 and miR-378a-3p in peripheral blood and mouse cardiomyocytes of patients with myocardial infarction. MTT assay, flow cytometry, Caspase-3 kit and transwell assay were used to detect the effects of lncRNA NEAT1 and miR-378a-3p on cardiomyocyte proliferation, apoptosis and migration. Target gene prediction and screening, luciferase reporter assays were used to verify downstream target genes for lncRNA NEAT1 and miR-378a-3p. Western blotting was used to detect the protein expression of Atg12 and related autophagy genes.

RESULTS

lncRNA NEAT1 was highly expressed in peripheral blood and mouse cardiomyocytes of patients with myocardial infarction. Moreover, lncRNA NEAT1 significantly promoted cell proliferation and migration of cardiomyocytes. In addition, lncRNA NEAT1 inhibited miR-378a-3p expression, and miR-378a-3p inhibited Atg12 expression, while lncRNA NEAT1 regulated expression of Atg12 and related autophagic factors via miR-378a-3p. Knockout of microRNA-378-3p reversed the effects of NEAT1 silencing on cell damage.

CONCLUSION

lncRNA NEAT1 can regulate the proliferation of cardiomyocytes by regulating miR-378-3p/Atg12 axis, thus accelerating the occurrence and development of cardiomyocytes.

Long non-coding RNA NEAT1 overexpression associates with increased exacerbation risk, severity, and inflammation, as well as decreased lung function through the interaction with microRNA-124 in asthma

Background

This study aimed to explore the association of long non‐coding RNA nuclear‐enriched abundant transcript 1 (lncRNA NEAT1) with exacerbation risk, lung function, and inflammatory cytokines in asthma.

Methods

A total of 170 patients with asthma in exacerbation, 170 patients with asthma in remission, and 170 healthy controls (HCs) were enrolled, and their plasma samples were collected. The expressions of lncRNA NEAT1 and microRNA‐124 (miRNA‐124) in plasma were detected by real‐time quantitative polymerase chain reaction; inflammatory cytokines in plasma were measured by the Enzyme‐linked immunosorbent assay (ELISA); and pulmonary ventilation function was detected by examination of forced expiratory volume in 1 second (FEV1) and forced vital capacity (FVC).

Results

LncRNA NEAT1 expression was upregulated in asthma patients in exacerbation compared with HCs and asthma patients in remission, and receiver operating characteristic curve exhibited that it was of good value in distinguishing asthma patients in exacerbation from HCs (AUC: 0.869 (0.830‐0.908)) and asthma patients in remission (AUC: 0.775 (0.724‐0.825)). Furthermore, lncRNA NEAT1 was positively correlated with exacerbation severity, TNF‐α, IL‐1β, and IL‐17, but negatively correlated with IL‐10, FEV₁/FVC and FEV₁%predicted in asthma patients. Additionally, lncRNA NEAT1 was negatively correlated with miR‐124, and miR‐124 was negatively associated with exacerbation risk, exacerbation severity, and inflammation, but positively associated with lung function in asthma patients.

Conclusion

Circulating lncRNA NEAT1 exhibits potential to be a new biomarker for elevated exacerbation risk and severity of asthma.

Long non-coding RNA-NEAT1, a sponge for miR-98-5p, promotes expression of oncogene HMGA2 in prostate cancer

Increasing evidence demonstrated that noncoding RNAs (lncRNA, miRNA) play important roles in the cancer development. LncRNA NEAT1 functions as an oncogene in many cancers. However, the roles of NEAT1 in prostate cancer (PCa) remain largely unknown. In the present study, we aim to explore the molecular mechanism of NEAT1 in the development of PCa. We detected the expression levels of NEAT1 in a total of 16 benign prostatic hyperplasia tissues (BPH), 30 matched adjacent healthy control (HC) tissues and 30 PCa tissues, as well as PCa cell lines PC-3, DU-145, LNCaP and normal prostate epithelial cell line RWPE-1. The results showed that NEAT1 was significantly up-regulated in PCa tissues and PCa cell lines. Knockdown of NEAT1 can largely inhibit DU-145 and PC-3 cell growth and invasion. Bioinformatics analysis predicted NEAT1 has the binding site of miR-98-5p which can bind to the 3′UTR of HMGA2. And the expression level of NEAT1 has a positive correlation with HMAG2, while negative correlation with miR-98-5p in PCa cells. In addition, luciference assay and RNA immunoprecipitation (RIP) assay confirmed that NEAT1 can function as a competing endogenous RNA (ceRNA) by sponging miR-98-5p to active HMGA2. Moreover, silencing of HMGA2 can decrease the proliferation ability of PCa cells. Taken together, NEAT1/miR-98-5p/HMGA2 pathway is involved in the development and progression of PCa. NEAT1 could be recommended as a prognostic biomarker and inhibition of NEAT1 expression may be a promising strategy for PCa therapy.

Granulocytic myeloid-derived suppressor cells contribute to IFN-I signaling activation of B cells and disease progression through the lncRNA NEAT1-BAFF axis in systemic lupus erythematosus

Activation of interferon (IFN)-I signaling in B cells contributes to the pathogenesis of systemic lupus erythematosus (SLE). Recent studies have shown that myeloid-derived suppressor cells (MDSCs) significantly expand in SLE patients and lupus-prone MRL/lpr mice and contribute to the pathogenesis of SLE. However, the role of SLE-derived MDSCs in regulating IFN-I signaling activation of B cells remains unknown. Here, we demonstrate that expansions of MDSCs, including granulocyte (G)-MDSCs and monocytic (M)-MDSCs, during the progression of SLE were correlated with the IFN-I signature of B cells. Interestingly, G-MDSCs from MRL/lpr mice, but not M-MDSCs, could significantly promote IFN-I signaling activation of B cells and contribute to the pathogenesis of SLE. Mechanistically, we identified that the long non-coding RNA NEAT1 was over-expressed in G-MDSCs from MRL/lpr mice and could induce the promotion of G-MDSCs on IFN-I signaling activation of B cells through B cell-activating factor (BAFF) secretion. Importantly, NEAT1 deficiency significantly attenuated the lupus symptoms in pristane-induced lupus mice. In addition, there was a positive correlation between NEAT1 and BAFF with the IFN signature in SLE patients. In conclusion, G-MDSCs may contribute to the IFN signature in SLE B cells through the NEAT1-BAFF axis, highlighting G-MDSCs as a potential therapeutic target to treat SLE.

Long non-coding RNA NEAT1 predicts elevated chronic obstructive pulmonary disease (COPD) susceptibility and acute exacerbation risk, and correlates with higher disease severity, inflammation, and lower miR-193a in COPD patients

This study aimed to explore the value of long non-coding RNA nuclear enriched abundant transcript 1 (lnc-NEAT1) in predicting chronic obstructive pulmonary disease (COPD) susceptibility and acute exacerbation risk, and to investigate the correlation of lnc-NEAT1 with disease severity, inflammation level, and miR-193a in COPD patients. 90 AECOPD patients, 90 stable COPD patients and 90 healthy controls were consecutively recruited. Severity of airflow obstruction in COPD patients was defined by GOLD guidelines. Plasma samples were collected from all participants, then lnc-NEAT1 and miR-193a expressions were measured by qPCR, and TNF-α, IL-1β, IL-6, and IL-17 were measured by ELISA. Lnc-NEAT1 expression was elevated in AECOPD patients and stable COPD patients compared to healthy controls, as well as in AECOPD patients compared to stable COPD patients; moreover, ROC curves showed that lnc-NEAT1 predicted increased COPD susceptibility and acute exacerbation risk of COPD. Also, lnc-NEAT1 expression positively correlated with GOLD stage and levels of TNF-α, IL-1β, IL-6 and IL-17 in both AECOPD and stable COPD patients. Furthermore, lnc-NEAT1 expression negatively correlated with miR-193a expression, and miR-193a could predict decreased COPD susceptibility and acute exacerbation risk, and negatively correlated with GOLD stage and levels of TNF-α, IL-1β, IL-6 and IL-17 in both AECOPD and stable COPD patients. lnc-NEAT1 predicts elevated COPD susceptibility and increased acute exacerbation risk, and positively correlates with disease severity as well as inflammation, but negatively associates with miR-193a in COPD patients.

YY1-induced upregulation of lncRNA NEAT1 contributes to OGD/R injury-induced inflammatory response in cerebral microglial cells via Wnt/β-catenin signaling pathway

Stroke can lead to the serious long-term neurological disability. The dysregulation of long non-coding RNAs (lncRNAs) has been proven to be a pivotal factor for the progression of ischemic stroke. However, it is largely unknown whether lncRNAs regulated the OGD/R injury of cerebral microglial cells. In this study, we designed experiments to reveal the role of lncRNA Nuclear Enriched Abundant Transcript 1 (NEAT1) in the OGD/R injury of microglial cells. We found that NEAT1 contributed to the OGD/R injury and neuroinflammation damage in microglial cells. Moreover, the molecular mechanism involved in the NEAT1-mediated OGD/R injury. Mechanism investigation revealed that NEAT1 was upregulated by the transcription factor YY1. Moreover, Western blot analysis suggested that NEAT1 enhance the protein levels of core factors of Wnt/β-catenin signaling pathway, indicating that NEAT1 contributed to the activation of Wnt/β-catenin signaling pathway. Rescue assays were carried out in the microglial cells treated with OGD/R. The results showed that NEAT1 regulated the OGD/R injury and neuroinflammation damage via Wnt/β-catenin signaling pathway. In conclusion, our findings suggested that YY1-induced upregulation of NEAT1 contributed to the OGD/R injury and neuroinflammation damage of microglial cells via Wnt/β-catenin signaling pathway.

The Long Noncoding RNA NEAT1 Targets miR-34a-5p and Drives Nasopharyngeal Carcinoma Progression via Wnt/β-Catenin Signaling

PURPOSE

Long noncoding RNA nuclear paraspeckle assembly transcript 1 (NEAT1) has been deemed an oncogene in many human cancers. However, the underlying mechanism of NEAT1 in nasopharyngeal carcinoma (NPC) progression remains largely unclear.

MATERIALS AND METHODS

Quantitative real-time PCR assay was performed to assess the expression of NEAT1 and miR-34a-5p in NPC tissues and cells. Western blot analysis was used to observe cell epithelial to mesenchymal transition (EMT) and the activation of Wnt/β-catenin signaling in 5-8F cells. MiRNA directly interacting with NEAT1 were verified by dual-luciferase reporter assay and RNA immunoprecipitation. Cell proliferation ability was determined by CCK-8 assay, and cell migration and invasion capacities were assessed by transwell assays. An animal model was used to investigate the regulatory effect of NEAT1 on tumor growth in vivo.

RESULTS

Our data revealed that NEAT1 is upregulated, while miR-34a-5p is downregulated in NPC tissues and cell lines. NEAT1 knockdown repressed tumor growth in vitro and in vivo. Additionally, we discovered that NEAT1 directly binds to miR-34a-5p and suppresses miR-34a-5p expression. Moreover, NEAT1 knockdown exerted suppression effects on cell proliferation, migration, invasion, and EMT by miR-34a-5p. NEAT1 knockdown blocked Wnt/β-catenin signaling via miR-34a-5p.

CONCLUSION

Our study demonstrated that NEAT1 targets miR-34a-5p at least partly to drive NPC progression by regulating Wnt/β-catenin signaling, suggesting a potential therapeutic target for NPC.

Investigations on the mechanism of progesterone in inhibiting endometrial cancer cell cycle and viability via regulation of long noncoding RNA NEAT1/microRNA-146b-5p mediated Wnt/β-catenin signaling

Progesterone is often used to protect the endometrium and prevent endometrial cancer. An intensive study on its molecular mechanism in endometrial cancer would contribute to the development of more promising therapies. Relevant lncRNAs and mRNAs expression data in endometrial cancer cell line Ishikawa pretreated and post-treated with progesterone were derived from Gene Expression Omnibus (accession no. GSE29435), and then we analyzed long noncoding RNAs and mRNAs with differential expressions in two different conditions. The Cytoscape software, TargetScan, miRanda, and Human microRNA Disease Database (HMDD) websites were employed. Gene set enrichment analysis (GSEA) was used to determine related Kyoto Encyclopedia of Genes and Genomes pathways alteration in Ishikawa cells treated with progesterone. In addition to bioinformatics analysis, Reverse Transcription-Polymerase Chain Reaction (RT-PCR), Western blot, and dual-luciferase reporter assays were performed. The impact of progesterone on cell propagation and cell cycle was testified by colony formation and flow cytometry analysis. LncRNA nuclear enriched abundant transcript 1 (NEAT1) was the most significantly downregulated lncRNA in endometrial cancer cells treated with progesterone. Lymphoid enhancing factor 1 (LEF1) was positively associated with NEAT1, and eventually hsa_miR-146b-5p was validated to target both LEF1 and NEAT1. Wnt/β-catenin signaling pathway was identified to involve in endometrial cancer. NEAT1 or LEF1 was overexpressed in endometrial cancer cells while downregulated following post-treatment with progesterone. Conversely, miR-146b-5p was notably decreased in Ishikawa cells while upregulated after treatment with progesterone. Downstream gene c-myc or MMP9 regulated by upstream gene LEF1 in Wnt/β-catenin signaling pathway was remarkably increased in Ishikawa cells and positively related with NEAT1. Progesterone inhibited cell cycle and viability through regulating NEAT1/miR-146b-5p axis via Wnt/β-catenin signaling pathway. Progesterone exerted suppressive influence on endometrial cancer progression via regulation of lncRNA NEAT1/miR-146b-5p-mediated Wnt/β-catenin signaling pathway, which might reveal new strategies for developing more effective therapeutics. © 2018 IUBMB Life, 71(1):223-234, 2019.

LncRNA NEAT1 facilitates survival and angiogenesis in oxygen-glucose deprivation (OGD)-induced brain microvascular endothelial cells (BMECs) via targeting miR-377 and upregulating SIRT1, VEGFA, and BCL-XL

OBJECTIVE

The present study was designed to investigate the mechanism by which lncRNA NEAT1 regulates survival and angiogenesis in oxygen-glucose deprivation (OGD)-induced brain microvascular endothelial cells (BMECs).

METHODS

OGD-treated BMECs were used to mimic cerebral ischaemia in vitro. The expression of lncRNA NEAT1 and miR-377 and proteins including VEGFA, SIRT1, and BCL-XL were measured by real-time quantitative PCR (qRT-PCR) and western blot, respectively. Cell viability and caspase 3 activity of BMECs under different conditions were determined using MTT and caspase activity assays, respectively. Matrigel-based angiogenesis assays were employed to evaluate the effect of lncRNA NEAT1 on angiogenesis. A dual-luciferase reporter assay was used to validate direct binding of miR-377 to putative targets.

RESULTS

OGD exposure reduced the cell viability of BMECs. Upregulation of lncRNA NEAT1 and downregulation of miR-377 were also observed under OGD conditions. Knockdown of lncRNA NEAT1 inhibited angiogenesis and aggravated apoptosis in OGD-induced BMECs. Meanwhile, the expression level of miR-377 was upregulated while its downstream targets (VEGFA, SIRT1, and BCL-XL) were downregulated after lncRNA NEAT1 knockdown. Furthermore, miR-377 inhibited the angiogenesis and survival of OGD-induced BMECs. The expression of VEGFA, SIRT1, and BCL-XL were all attenuated by miR-377 overexpression. The dual-luciferase reporter assay proved miR-377 targeted the 3' UTR sequences of lncRNA NEAT1, VEGFA, SIRT1, and BCL-XL.

CONCLUSION

lncRNA NEAT1 facilitated the survival and angiogenesis of OGD-induced BMECs via targeting miR-377 and promoting the expression of VEGFA, SIRT1, and BCL-XL, suggesting that lncRNA NEAT1 could be a promising target for cerebral ischaemia treatment.