GAS5 promotes cytarabine induced myelosuppression via inhibition of hematopoietic stem cell differentiation.

Cytarabine (Ara-C) is widely used in the induction chemotherapy for acute myeloid leukemia (AML). Association between LncRNA GAS5 genetic polymorphism and the recovery of hematopoietic function after Ara-C-based chemotherapy is observed. This study aimed to identify whether intervention of GAS5 expression and GAS5 genotype affect Ara-C-induced inhibition of hematopoietic stem cells (HSCs) differentiation. In this study, cord blood-derived CD34+ cells were cultured in vitro, and a cell model of myelosuppression was established by treatment of CD34+ cells with Ara-C. The effect of GAS5 overexpression, Ara-C treatment, and GAS5 rs55829688 genotype on the hematopoietic colony-forming ability of CD34+ cells was assessed using methylcellulose-based colony forming unit assay. GAS5 overexpression slowed down the proliferation of cord blood-derived CD34+ cells significantly (p < 0.05) and decreased their ability to form hematopoietic colonies in vitro. Ara-C significantly reduced the hematopoietic colony-forming ability of CD34+ cells in vitro (p < 0.0001), and overexpressing GAS5 further decreased the number of hematopoietic colonies. GAS5 expression was higher in CD34+ cells than in CD34- cells, and positively correlated with GATA1 mRNA expression in CD34+ cells in vitro culture. However, GAS5 genotype had no effect on the total number of hematopoietic colonies formed from cord blood-derived CD34+ cells. In conclusion, our study highlights that GAS5 inhibited the in vitro proliferation and reduced the hematopoietic colony-forming ability of cord blood-derived CD34+ cells, with the most pronounced effect observed on CFU-GEMM formation. GAS5 also enhanced the inhibitory effect of Ara-C on the in vitro hematopoietic ability of CD34+ HSCs.

LncRNA GAS5 regulated by FTO-mediated m6A demethylation promotes autophagic cell death in NSCLC by targeting UPF1/BRD4 axis.

Long non-coding RNA (lncRNA) growth arrest-specific transcript 5 (GAS5) has been shown to be a regulator for many cancers, including non-small cell lung cancer (NSCLC). Therefore, its role and mechanism in the process of NSCLC deserve to be further revealed. The expression levels of GAS5, fat mass and obesity-associated protein (FTO) and bromodomain-containing protein 4 (BRD4) were detected by quantitative real-time PCR. Western blot analysis was used to examine the protein expression of FTO, BRD4, up-frameshift protein 1 (UPF1) and autophagy-related markers. Methylated RNA immunoprecipitation was used to assess the m6A level of GAS5 regulated by FTO. Cell proliferation and apoptosis were determined using MTT assay, EdU assay and flow cytometry. Autophagy ability was assessed by immunofluorescence staining and transmission electron microscope. Xenograft tumor model was constructed to explore the effects of FTO and GAS5 on NSCLC tumor growth in vivo. The interaction between UPF1 and GAS5 or BRD4 was confirmed by pull-down assay, RIP assay, dual-luciferase reporter assay, and chromatin immunoprecipitation. Fluorescent in situ hybridization was used to analyze the co-localization of GAS5 and UPF1. Actinomycin D treatment was employed to evaluate BRD4 mRNA stability. GAS5 was downregulated in NSCLC tissues and was associated with poor prognosis in NSCLC patients. FTO was highly expressed in NSCLC, and it inhibited GAS5 expression by reducing GAS5 m6A methylation level. GAS5 suppressed by FTO could promote the autophagic death of NSCLC cells in vitro and inhibit NSCLC tumor growth in vivo. In addition, GAS5 was able to interact with UPF1 to reduce the mRNA stability of BRD4. Knockdown of BRD4 reversed the inhibition of GAS5 or UPF1 silencing on the autophagic cell death of NSCLC. The findings of the study showed that lncRNA GAS5 mediated by FTO could contribute to the autophagic cell death of NSCLC by interacting with UPF1 to reduce BRD4 mRNA stability, suggesting that GAS5 might be a vital therapy target for NSCLC progression.

Neuron-derived exosomes mediate sevoflurane-induced neurotoxicity in neonatal mice via transferring lncRNA Gas5 and promoting M1 polarization of microglia.

Sevoflurane exposure during rapid brain development induces neuronal apoptosis and causes memory and cognitive deficits in neonatal mice. Exosomes that transfer genetic materials including long non-coding RNAs (lncRNAs) between cells play a critical role in intercellular communication. However, the lncRNAs found in exosomes derived from neurons treated with sevoflurane and their potential role in promoting neurotoxicity remain unknown. In this study, we investigated the role of cross-talk of newborn mouse neurons with microglial cells in sevoflurane-induced neurotoxicity. Mouse hippocampal neuronal HT22 cells were exposed to sevoflurane, and then co-cultured with BV2 microglial cells. We showed that sevoflurane treatment markedly increased the expression of the lncRNA growth arrest-specific 5 (Gas5) in neuron-derived extracellular vesicles, which inhibited neuronal proliferation and induced neuronal apoptosis by promoting M1 polarization of microglia and the release of inflammatory cytokines. We further revealed that the exosomal lncRNA Gas5 significantly upregulated Foxo3 as a competitive endogenous RNA of miR-212-3p in BV2 cells, and activated the NF-κB pathway to promote M1 microglial polarization and the secretion of inflammatory cytokines, thereby exacerbating neuronal damage. In neonatal mice, intracranial injection of the exosomes derived from sevoflurane-treated neurons into the bilateral hippocampi significantly increased the proportion of M1 microglia, inhibited neuronal proliferation and promoted apoptosis, ultimately leading to neurotoxicity. Similar results were observed in vitro in BV2 cells treated with the CM from HT22 cells after sevoflurane exposure. We conclude that sevoflurane induces the transfer of lncRNA Gas5-containing exosomes from neurons, which in turn regulates the M1 polarization of microglia and contributes to neurotoxicity. Thus, modulating the expression of lncRNA Gas5 or the secretion of exosomes could be a strategy for addressing sevoflurane-induced neurotoxicity.

Expression of long non-coding RNA GAS5 by first trimester screening predicts the occurrence of gestational hypertension and pre-eclampsia.

AIMS: Hypertensive disorders of pregnancy (HDP) is a unique disease during gestational period, which is detrimental to pregnancy outcome. This study examined the clinical significance of long non-coding RNA GAS5 in gestational hypertension (GH) and preeclampsia (PE), aiming to explore potential biomarkers for the disease detection. METHODS: 180 pregnant women with HPD including 90 cases with GH and 90 cases with PE, and another 100 healthy pregnant women were enrolled. Serum GAS5 levels were measured by RT-qPCR method. The diagnostic performance of GAS5 was assessed in GH and PE through plotting receiver operating characteristic (ROC) curve. Logistic regression was applied for the identification of independent factors. RESULTS: Elevated serum GAS5 was identified in GH patients, and its diagnostic performance in discriminating GH cases from healthy people was determined by ROC curve. Serum GAS5 was positively associated with SBP, DBP, LDL-C and CRP values. Cases with PE had an increased serum GAS5 level relative to those with GH. Serum GAS5 was identified to be an independent predictor for PE, and can differentiate PE cases from GH ones. with a good diagnositc performance. Cases with high levels of serum GAS5 had a high risk of poor pregnancy outcomes. CONCLUSION: Elevated serum GAS5 could serve as an effective diagnostic biomarker in discriminating GH patients from healthy people by first trimester screening. Detection of serum GAS5 level has a certain predictive value for PE.

Systematic Identification of Long Noncoding RNAs during Three Key Organogenesis Stages in Zebrafish.

Thousands of lncRNAs have been found in zebrafish embryogenesis and adult tissues, but their identification and organogenesis-related functions have not yet been elucidated. In this study, high-throughput sequencing was performed at three different organogenesis stages of zebrafish embryos that are important for zebrafish muscle development. The three stages were 10 hpf (hours post fertilization) (T1), 24 hpf (T2), and 36 hpf (T3). LncRNA gas5, associated with muscle development, was screened out as the next research target by high-throughput sequencing and qPCR validation. The spatiotemporal expression of lncRNA gas5 in zebrafish embryonic muscle development was studied through qPCR and in situ hybridization, and functional analysis was conducted using CRISPR/Cas9 (clustered regularly interspaced short palindromic repeats/Cas9, CRISPR/Cas9). The results were as follows: (1) A total of 1486 differentially expressed lncRNAs were identified between T2 and T1, among which 843 lncRNAs were upregulated and 643 were downregulated. The comparison with T3 and T2 resulted in 844 differentially expressed lncRNAs, among which 482 lncRNAs were upregulated and 362 lncRNAs were downregulated. A total of 2137 differentially expressed lncRNAs were found between T3 and T1, among which 1148 lncRNAs were upregulated and 989 lncRNAs were downregulated, including lncRNA gas5, which was selected as the target gene. (2) The results of spatiotemporal expression analysis showed that lncRNA gas5 was expressed in almost all detected embryos of different developmental stages (0, 2, 6, 10, 16, 24, 36, 48, 72, 96 hpf) and detected tissues of adult zebrafish. (3) After lncRNA gas5 knockout using CRISPR/Cas9 technology, the expression levels of detected genes related to muscle development and adjacent to lncRNA gas5 were more highly affected in the knockout group compared with the control group, suggesting that lncRNA gas5 may play a role in embryonic muscle development in zebrafish. (4) The results of the expression of the skeletal myogenesis marker myod showed that the expression of myod in myotomes was abnormal, suggesting that skeletal myogenesis was affected after lncRNA gas5 knockout. The results of this study provide an experimental basis for further studies on the role of lncRNA gas5 in the embryonic skeletal muscle development of zebrafish.

The Role of Long Non-Coding RNAs in Ovarian Cancer Cells.

Among the most deadly malignancies that strike women worldwide, ovarian cancer is still one of the most common. The primary factor affecting a patient's survival is early lesion discovery. Unfortunately, because ovarian cancer is a sneaky illness that usually manifests as nonspecific symptoms only in advanced stages, its early detection and screening are challenging. A lot of research is being conducted on effective methods of diagnosing and treating ovarian cancer. Recently, non-coding RNAs (ncRNAs) have gained great popularity, which are considered to be the main regulators of many cellular processes, especially those occurring in cancer. LncRNAs are also being studied for their therapeutic use in the treatment of ovarian cancer and their use in diagnostics and as indicators of poor prognosis. In this article, we reviewed lncRNAs described in the literature that may play an important role in ovarian cancer.

LncRNA GAS5 suppresses TGF-ß1-induced transformation of pulmonary pericytes into myofibroblasts by recruiting KDM5B and promoting H3K4me2/3 demethylation of the PDGFRα/ß promoter.

BACKGROUND: Idiopathic pulmonary fibrosis (IPF) is a condition that may cause persistent pulmonary damage. The transformation of pericytes into myofibroblasts has been recognized as a key player during IPF progression. This study aimed to investigate the functions of lncRNA growth arrest-specific transcript 5 (GAS5) in myofibroblast transformation during IPF progression. METHODS: We created a mouse model of pulmonary fibrosis (PF) via intratracheal administration of bleomycin. Pericytes were challenged with exogenous transforming growth factor-ß1 (TGF-ß1). To determine the expression of target molecules, we employed quantitative reverse transcription-polymerase chain reaction, Western blotting, and immunohistochemical and immunofluorescence staining. The pathological changes in the lungs were evaluated via H&E and Masson staining. Furthermore, the subcellular distribution of GAS5 was examined using FISH. Dual-luciferase reporter assay, ChIP, RNA pull-down, and RIP experiments were conducted to determine the molecular interaction. RESULTS: GAS5 expression decreased whereas PDGFRα/ß expression increased in the lungs of IPF patients and mice with bleomycin-induced PF. The in vitro overexpression of GAS5 or silencing of PDGFRα/ß inhibited the TGF-ß1-induced differentiation of pericytes to myofibroblasts, as evidenced by the upregulation of pericyte markers NG2 and desmin as well as downregulation of myofibroblast markers α-SMA and collagen I. Further mechanistic analysis revealed that GAS5 recruited KDM5B to promote H3K4me2/3 demethylation, thereby suppressing PDGFRα/ß expression. In addition, KDM5B overexpression inhibited pericyte-myofibroblast transformation and counteracted the promotional effect of GAS5 knockdown on pericyte-myofibroblast transformation. Lung fibrosis in mice was attenuated by GAS5 overexpression but promoted by GAS5 deficiency. CONCLUSION: GAS5 represses pericyte-myofibroblast transformation by inhibiting PDGFRα/ß expression via KDM5B-mediated H3K4me2/3 demethylation in IPF, identifying GAS5 as an intervention target for IPF.

Identification of signalling downstream of the transcription factor forkhead box protein M1 that protects against endoplasmic reticulum stress in a diabetic foot ulcer model.

AIMS: Diabetic foot ulcer (DFU) has a significant impact on the quality of life of diabetic mellitus (DM) patients. Here, we aimed to explore the molecules with aberrant expression and their regulatory mechanisms in DFU. METHODS: The expression of gene and protein was examined using quantitative polymerase chain reaction (qPCR) and western blot. Pearson's correlation analysis was used to analyse interactions among FOXM1, GAS5 and SDF4. Immunofluorescence was used to detect PDI and GRP78 expression. Flow cytometry was used to assess cell apoptosis. Tube formation assay was used to determine angiogenic capacity. Fluorescence in situ hybridization (FISH) assay was employed to determine the cellular localization of GAS5 and SDF4 in human umbilical vein endothelial cells (HUVECs). The interactions among FOXM1, GAS5 and SDF4 were validated by chromatin immunoprecipitation (ChIP), luciferase, RNA pull-down and RNA immunoprecipitation (RIP) assays. RESULTS: FOXM1, GAS5 and SDF4 were decreased in the skin tissues of DFU patients. High glucose (HG) stimulation induced endoplasmic reticulum (ER) stress and cell apoptosis but suppressed angiogenesis in HUVECs, which were abolished by FOXM1 overexpression. FOXM1 promoted GAS5 transcriptional activity, resulting in increased GAS5 expression, and GAS5 knockdown reversed the effects of FOXM1 overexpression in HG-treated HUVECs. Moreover, GAS5 recruited TAF15 to promote SDF4 expression in HUVECs. GAS5 overexpression inhibited ER stress, cell apoptosis and induced angiogenesis in HG-treated HUVECs which could be reversed by silencing SDF4. CONCLUSION: Our results revealed that FOXM1 suppressed ER stress, cell apoptosis and promoted angiogenesis in HG-induced HUVECs via mediating GAS5/TAF15/SDF4 axis, providing a novel therapeutic molecule mechanism for DFU.

lncRNAs dysregulation in monocytes from primary antiphospholipid syndrome patients: a bioinformatic and an experimental proof-of-concept approach.

BACKGROUND: Antiphospholipid syndrome (APS) is the main cause of acquired thrombophilia where peripheral circulating cells such as monocytes have a key role. Currently, several studies have linked long non-coding RNAs (lncRNAs) in different inflammatory and autoimmune processes, including lupus. However, the role of lncRNAs in antiphospholipid syndrome is unknown, therefore, we aimed to select and measure expression levels of three lncRNAs based on its abundance in monocytes from APS patients. METHODS: Selection of lncRNAs candidates were carried out based on its abundance in monocytes and their relationship with Perez-Sanchez miRNA signature by using miRNet 2.0 bioinformatic tool, then lncRNAs expression levels was measured in monocytes by RT-qPCR. RESULTS: This is the first study to report that lncRNAs: FGD5-AS1, OIP5-AS1 and GAS5 are promising candidates for play a role on APS monocytes and they are expressed differently between patients and controls. CONCLUSIONS: OIP5-AS1, FGD5-AS1 and GAS5 are downregulated on monocytes from APS patients.

LncRNA GAS5 Attenuates Cardiac Electrical Remodeling Induced by Rapid Pacing via the miR-27a-3p/HOXa10 Pathway.

Previous studies indicated long non-coding RNAs (lncRNAs) participated in the pathogenesis of atrial fibrillation (AF). However, little is known about the role of lncRNAs in AF-induced electrical remodeling. This study aimed to investigate the regulatory effect of lncRNA GAS5 (GAS5) on the electrical remodeling of neonatal rat cardiomyocytes (NRCMs) induced by rapid pacing (RP). RNA microarray analysis yielded reduced GAS5 level in NRCMs after RP. RT-qPCR, western blot, and immunofluorescence yielded downregulated levels of Nav1.5, Kv4.2, and Cav1.2 after RP, and whole-cell patch-clamp yielded decreased sodium, potassium, and calcium current. Overexpression of GAS5 attenuated electrical remodeling. Bioinformatics tool prediction analysis and dual luciferase reporter assay confirmed a direct negative regulatory effect for miR-27a-3p on lncRNA-GAS5 and HOXa10. Further analysis demonstrated that either miR-27a-3p overexpression or the knockdown of HOXa10 further downregulated Nav1.5, Kv4.2, and Cav1.2 expression. GAS5 overexpression antagonized such effects in Nav1.5 and Kv4.2 but not in Cav1.2. These results indicate that, in RP-treated NRCMs, GAS5 could restore Nav1.5 and Kv4.2 expression via the miR-27a-3p/HOXa10 pathway. However, the mechanism of GAS5 restoring Cav1.2 level remains unclear. Our study suggested that GAS5 regulated cardiac ion channels via the GAS5/miR-27a-3p/HOXa10 pathway and might be a potential therapeutic target for AF.

Evaluating lncRNA Expression Patterns during HIV-1 Treatment Interruption.

Lately, the interest in long non-coding RNAs (lncRNAs) as potential drug targets and predictive markers in the context of HIV-1 has peaked, but their in vivo expression and regulation remains largely unexplored. Therefore, the present study examined lncRNA expression patterns during a clinical antiretroviral treatment interruption (ATI) trial. Peripheral blood mononuclear cells were isolated from ten patients at four timepoints: prior to ATI, 7-15 days after stop, at viral rebound and 3 months post antiretroviral therapy re-initiation. RNA was extracted and RT-qPCR on five known HIV-1-related lncRNAs (HEAL, MALAT1, NEAT1, GAS5 and NRON) was performed and correlated with HIV-1 and host marker expression. All lncRNAs correlated stronger with interferon stimulated genes (ISGs) than with HIV-1 reservoir and replication markers. However, one lncRNA, HEAL, showed significant upregulation at viral rebound during ATI compared to baseline and re-initiation of therapy (p = 0.0010 and p = 0.0094, respectively), following a similar viral-load-driven expression pattern to ISGs. In vitro knockdown of HEAL caused a significant reduction in HIV-1 infection levels, validating HEAL's importance for HIV-1 replication. We conclude that the HIV-1-promoting lncRNA HEAL is upregulated at viral rebound during ATI, most likely induced by viral cues.

Whole Blood Expression Levels of Long Noncoding RNAs: HOTAIRM1, GAS5, MZF1-AS1, and OIP5-AS1 as Biomarkers in Adolescents with Obesity-Related Asthma.

Asthma is a heterogeneous entity encompassing distinct endotypes and varying phenotypes, characterized by common clinical manifestations, such as shortness of breath, wheezing, and variable airflow obstruction. Two major asthma endotypes based on molecular patterns are described: type 2 endotype (allergic-asthma) and T2 low endotype (obesity-related asthma). Long noncoding RNAs (lncRNAs) are transcripts of more than 200 nucleotides in length, currently involved in many diverse biological functions, such as chromatin remodeling, gene transcription, protein transport, and microRNA processing. Despite the efforts to accurately classify and discriminate all the asthma endotypes and phenotypes, if long noncoding RNAs could play a role as biomarkers in allergic asthmatic and adolescent obesity-related asthma, adolescents remain unknown. To compare expression levels of lncRNAs: HOTAIRM1, OIP5-AS1, MZF1-AS1, and GAS5 from whole blood of Healthy Adolescents (HA), Obese adolescents (O), allergic asthmatic adolescents (AA) and Obesity-related asthma adolescents (OA). We measured and compared expression levels from the whole blood of the groups mentioned above through RT-q-PCR. We found differentially expressed levels of these lncRNAs between the groups of interest. In addition, we found a discriminative value of previously mentioned lncRNAs between studied groups. Finally, we generated an interaction network through bioinformatics. Expression levels of OIP5-AS1, MZF1-AS1, HOTAIRM1, and GAS5 in whole blood from the healthy adolescent population, obese adolescents, allergic asthma adolescents, and obesity-related asthma adolescents are differently expressed. Moreover, these lncRNAs could act as molecular biomarkers that help to discriminate between all studied groups, probably through molecular mechanisms with several genes and miRNAs implicated.

Intron Editing Reveals SNORD-Dependent Maturation of the Small Nucleolar RNA Host Gene GAS5 in Human Cells.

The GAS5 gene encodes a long non-coding RNA (lncRNA) and intron-located small nucleolar RNAs (snoRNAs). Its structure, splice variants, and diverse functions in mammalian cells have been thoroughly investigated. However, there are still no data on a successful knockout of GAS5 in human cells, with most of the loss-of-function experiments utilizing standard techniques to produce knockdowns. By using CRISPR/Cas9 to introduce double-strand breaks in the terminal intronic box C/D snoRNA genes (SNORDs), we created monoclonal cell lines carrying continuous deletions in one of the GAS5 alleles. The levels of GAS5-encoded box C/D snoRNAs and lncRNA GAS5 were assessed, and the formation of the novel splice variants was analyzed. To comprehensively evaluate the influence of specific SNORD mutations, human cell lines with individual mutations in SNORD74 and SNORD81 were obtained. Specific mutations in SNORD74 led to the downregulation of all GAS5-encoded SNORDs and GAS5 lncRNA. Further analysis revealed that SNORD74 contains a specific regulatory element modulating the maturation of the GAS5 precursor transcript. The results demonstrate that the maturation of GAS5 occurs through the m6A-associated pathway in a SNORD-dependent manner, which is a quite intriguing epitranscriptomic mechanism.

Long noncoding RNA Gas5 induces cell apoptosis and inhibits tumor growth via activating the CHOP-dependent endoplasmic reticulum stress pathway in human hepatoblastoma HepG2 cells.

In recent years, long noncoding RNAs (lncRNAs) have been demonstrated to be important tumor-associated regulatory factors. LncRNA growth arrest-specific transcript 5 (Gas5) acts as an anti-oncogene in most cancers. Whether Gas5 acts as an oncogene or anti-oncogene in hepatocellular carcinoma (HCC) remains unclear. In the present study, the expression and role of Gas5 in HCC were investigated in vitro and in vivo. Lower expression levels of Gas5 were determined in HCC tissues and cells by quantitative reverse transcription-polymerase chain reaction. Overexpressed Gas 5 lentiviral vectors were constructed to analyze their influence on cell viability, migration, invasion, and apoptosis. Fluorescence in situ hybridization was used to identify the subcellular localization of Gas5. Protein complexes that bound to Gas5 were isolated from HepG2 cells through pull-down experiments and analyzed by mass spectrometry. A series of novel Gas5-interacting proteins were identified and bioinformatics analysis was carried out. These included ribosomal proteins, proteins involved in protein folding, sorting, and transportation in the ER, some nucleases and protein enzymes involved in gene transcription, translation, and other proteins with various functions.78 kDa glucose-regulated protein (GRP78) was identified as a direct target of Gas5 by Rip-qPCR and Western blot analysis assay. Gas5 inhibited HepG2 cell growth and induced cell apoptosis via upregulating CHOP to activate the ER stress signaling pathway. Further studies indicated that the knockdown of CHOP by shRNA partially reversed Gas5-mediated apoptosis in HepG2 cells. Magnetic resonance imaging showed that the ectopic expression of Gas5 inhibited the growth of HCC in nude mice. These findings suggest that Gas5 functions as a tumor suppressor and induces apoptosis through activation of ER stress by targeting the CHOP signal pathway in HCC.

Growth arrest-specific transcript 5 represses endometrial cancer development by promoting antitumor function of tumor-associated macrophages.

The tumor-suppressor role of long noncoding RNA (lncRNA) growth arrest-specific transcript 5 (GAS5) has been proven in various types of cancer. However, the specific function of GAS5 in tumor-associated macrophages (TAMs) of endometrial cancer (EC) is elusive. Quantitative PCR results showed that GAS5 expression decreased in EC tissues and primary TAMs from EC tumors. Tumor-associated macrophage infiltration was significantly positively associated with the developmental stage of EC. Direct coculture of GAS5-overexpressing TAMs and EC cells showed that GAS5 enhanced phagocytosis, antigen presentation, and activation of cytotoxic T cells, and repressed "Don't eat me" signals between TAMs and EC cells. Tumor formation in immunodeficient mice showed that GAS5-overexpressing macrophages could repress EC formation in vivo. GAS5 promoted M1 polarization by activating the microRNA-21- phosphatase and tensin homolog (PTEN)-AKT signaling pathway and directly repressing the nuclear accumulation and phosphorylation of oncogenic yes-associated protein 1 (YAP1) in TAMs. GAS5 inhibited the development of EC from both innate and adaptive immunity by transforming TAMs from a protumor to an antitumor phenotype. These antitumor effects of GAS5 on TAMs were mediated by the activation of the miR-21-PTEN-AKT pathway and inhibition of YAP1.

GAS5/METTL14/ESR1 genetic variants are related to the susceptibility of coronary heart disease.

The prevention and treatment of coronary heart disease (CHD) is a difficult problem to be solved urgently. Genetic factors play a crucial role in CHD development. This study aimed to investigate the association of GAS5/METTL14/ESR1 polymorphisms with CHD susceptibility. We carried out a case-control study that included 506 patients and 506 healthy subjects to detect the correlation between GAS5/METTL14/ESR1 polymorphisms and CHD risk in a Chinese population. Odds ratios (OR) and 95% confidence intervals (CI) were computed to assess the associations. Our study showed that GAS5 rs17359906 (OR 2.32, p = 0.020) and rs75315904 (OR 0.41, p = 0.039) were related to the risk of CHD in females. ESR1 rs6927072 (OR 1.76, p = 0.007) and rs4870061 (OR 0.74, p = 0.036) correlated with CHD risk in age ≤ 60 years. GAS5 rs17359906 (OR 0.10, p = 0.032) and ESR1 rs3020308 (OR 2.73, p = 0.041) were associated with an increased susceptibility to CHD in smokers. We also found that METTL14 rs4834698 (OR 1.57, p = 0.044) and ESR1 rs4870061 (OR 0.62, p = 0.040) were associated with CHD susceptibility in non-drinkers. Besides, METTL14 rs17050450 (OR 0.48, p = 0.029) and ESR1 rs3853248 (OR 1.61, p = 0.018) had the susceptibility of CHD patients with diabetes. Our study indicated that GAS5/METTL14/ESR1 polymorphisms were associated with CHD risk, which might provide a new understanding of CHD in a Chinese population.

The m6A demethylase FTO promotes renal epithelial-mesenchymal transition by reducing the m6A modification of lncRNA GAS5.

BACKGROUND: Renal interstitial fibrosis (RIF) is the main pathological change of a variety of chronic kidney diseases (CKD). Epigenetic modifications of fibrosis-prone genes regulate RIF progression. This study aimed to investigate long non-coding RNA (lncRNA) N6-methyladenosine (m6A) modification and its role in regulating RIF progression. METHODS: Unilateral ureteral occlusion (UUO) was employed to construct the RIF in vivo model; and TGF-ß1-treated HK-2 and HKC-8 cells were used for in vitro experiments. The mRNA and protein expressions were assessed using qRT-PCR and western blot. The proliferation and migration were evaluated by EdU assay and transwell assay, respectively. In addition, levels of inflammatory cytokines were determined by ELISA assay and qRT-PCR. Moreover, lncRNA GAS5 m6A level was detected using Me-RIP assay. HE and Masson staining were employed to evaluate fibrotic lesions of the kidney. RESULTS: FTO expression was elevated in HK-2 and HKC-8 cells after TGF-ß1 treatment and mouse kidney tissue following UUO, and lncRNA GAS5 was downregulated. LncRNA GAS5 overexpression or FTO silencing suppressed TGF-ß1-induced the increase of EMT-related proteins (Vimentin, Snail and N-cadherin) and inflammatory cytokines (IL-6, IL-1ß and TNF-α) levels in HK-2 cells. FTO suppressed lncRNA GAS5 expression by reducing the m6A modification of lncRNA GAS5. Additionally, FTO knockdown could suppress EMT process and inflammation response induced by TGF-ß1 and UUO in vitro and in vivo. As expected, FTO knockdown abrogated the promotion effects of lncRNA GAS5 silencing on TGF-ß1-induced EMT process and inflammation response in HK-2 and HKC-8 cells. CONCLUSION: FTO promoted EMT process and inflammation response through reducing the m6A modification of lncRNA GAS5.

LncRNA GAS5 promotes epilepsy progression through the epigenetic repression of miR-219, in turn affecting CaMKIIγ/NMDAR pathway.

It has been widely reported that dysregulated long-chain noncoding RNAs (lncRNAs) are closely associated with epilepsy. This study aimed to probe the function of lncRNA growth arrest-specific 5 (GAS5), microRNA (miR)-219 and Calmodulin-dependent protein kinase II (CaMKII)γ/N-methyl-D-aspartate receptor (NMDAR) pathway in epilepsy. Epileptic cell and animal models were constructed using magnesium deficiency treatment and diazepam injection, respectively. GAS5 and miR-219 expressions in epileptic cell and animal models were determined using qRT-PCR assay. The protein levels of CaMKIIγ, NMDAR and apoptosis-related proteins levels were assessed by western blot. Cell counting kit-8 (CCK-8) assay was employed to determine cell proliferation. Besides, TNFα, IL-1ß, IL-6 and IL-8 levels were analyzed using enzyme-linked immunosorbent assay (ELISA). Furthermore, cell apoptosis was evaluated using TUNEL staining and flow cytometric analysis. Finally, the binding relationship between GAS5 and EZH2 was verified using RIP and ChIP assay. Our results revealed that GAS5 was markedly upregulated in epileptic cell and animal models, while miR-219 was down-regulated. GAS5 knockdown dramatically increased cell proliferation of epileptic cells, whereas suppressed inflammation and the apoptosis. Furthermore, our results showed that GAS5 epigenetically suppressed transcriptional miR-219 expression via binding to EZH2. miR-219 mimics significantly enhanced cell proliferation of epileptic cells, while inhibited inflammation and the apoptosis, which was neutralized by CaMKIIγ overexpression. Finally, miR-219 inhibition reversed the effects of GAS5 silence on epileptic cells, which was eliminated by CaMKIIγ inhibition. In conclusion, GAS5 affected inflammatory response and cell apoptosis of epilepsy via inhibiting miR-219 and further regulating CaMKIIγ/NMDAR pathway (See graphic summary in Supplementary Material).

LncRNA SCIRT absorbs miR-221 to advance the expression of lncRNA GAS5 in oral squamous cell carcinoma to inhibit cancer cell apoptosis.

BACKGROUND: Although SCIRT has been reported to suppress breast cancer, its role in other cancers, such as oral squamous cell carcinoma (OSCC), is hardly known. We predicted that SCIRT might interact with miR-221 to target lncRNA GAS5 and analyzed the interaction between SCIRT and miR-221 in OSCC. METHODS: SCIRT and miR-221 expression levels were quantified using RT-qPCR. SCIRT subcellular localization was analyzed by subcellular fractionation assay. RNA pull-down assay was applied to study the interaction between SCIRT and miR-221. The role of SCIRT and miR-221 in regulating GAS5 expression was analyzed by overexpression assay and RT-qPCR. Cell apoptosis was analyzed by flow cytometry. RESULTS: SCIRT and GAS5 were downregulated, while miR-221 was overexpressed in OSCC. SCIRT was detected in both nucleus and cytoplasm and directly interacted with miR-221, while SCIRT overexpression failed to affect miR-221 expression. In addition, GAS5 expression was increased by SCIRT and decreased by miR-221. Moreover, SCIRT suppressed the role of miR-221 in suppressing GAS5 expression and OSCC cell apoptosis. CONCLUSION: SCIRT sponges miR-221 to upregulate lncRNA GAS5 in OSCC and inhibit cancer cell apoptosis.

The clinical value of long noncoding RNA GAS5 in acute ischemic stroke: Correlation with disease risk, inflammation, severity, and risk of recurrence.

BACKGROUND: Long noncoding RNA growth arrest-specific 5 (lnc-GAS5) is involved in the pathophysiology of acute ischemic stroke (AIS) by regulating vascular stenosis, inflammation, and neurocyte apoptosis. This study aimed to explore the clinical value of lnc-GAS5 in patients with AIS. METHODS: Plasma samples were collected from 120 patients with AIS at admission and 60 controls after enrollment, and lnc-GAS5 expression in the plasma of all participants was assessed by reverse transcription quantitative polymerase chain reaction. In patients with AIS, disease severity was evaluated using National Institute of Health Stroke Scale (NIHSS) score, and plasma inflammatory cytokine levels were measured by enzyme-linked immunosorbent assay. Recurrence-free survival (RFS) was calculated during a 36-month follow-up period. RESULTS: Lnc-GAS5 expression levels were higher in patients with AIS than in the controls (p < 0.001), and it had the potential to discriminate the controls from patients with AIS (area under the curve: 0.893, 95% confidence interval: 0.849-0.938). In patients with AIS, elevated lnc-GAS5 levels were positively correlated with NIHSS score (r = 0.397, p < 0.001), diabetes mellitus (p = 0.046), and higher levels of tumor necrosis factor alpha (TNF-α; r = 0.374, p < 0.001), interleukin-6 (IL-6; r = 0.223, p < 0.001), and interleukin-17A (IL-17A; r = 0.222, p = 0.015). The expression levels of lnc-GAS5 were also negatively correlated with the levels of interleukin-10 (IL-10; r = -0.350, p < 0.001) and RFS (p = 0.036). CONCLUSION: Lnc-GAS5 is correlated with higher susceptibility to AIS, inflammation, and severity, and can predict an increased risk of AIS recurrence, indicating that monitoring of lnc-GAS5 might improve the management of AIS.