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.

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.

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.

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.

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.

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).

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.

Relation of circulating lncRNA GAS5 and miR-21 with biochemical indexes, stenosis severity, and inflammatory cytokines in coronary heart disease patients.

BACKGROUND: Long noncoding RNA GAS5 (lnc-GAS5) and its target microRNA-21 (miR-21) regulate blood lipid, macrophages, Th cells, vascular smooth muscle cells to participate in atherosclerosis, and related coronary heart disease (CHD). The study aimed to further explore the linkage of their circulating expressions with common biochemical indexes, stenosis severity and inflammatory cytokines in CHD patients. METHODS: Ninety-eight CHD patients and 100 controls confirmed by coronary angiography were enrolled. Plasma samples were collected for lnc-GAS5 and miR-21 detection by reverse transcription-quantitative polymerase chain reaction and inflammatory cytokines determination by enzyme-linked immunosorbent assay. RESULTS: Lnc-GAS5 was increased in CHD patients compared with controls (2.270 (interquartile range [IQR]: 1.676-3.389) vs. 0.999 ([IQR: 0.602-1.409], p < 0.001), whereas miR-21 showed opposite tread (0.442 [IQR: 0.318-0.698] vs. 0.997 [IQR: 0.774-1.368], p < 0.001). In aspect of their intercorrelation, lnc-GAS5 negatively linked with miR-21 in CHD patients (p < 0.001) instead of controls (p = 0.211). Interestingly, among the common biochemical indexes, lnc-GAS5 related to decreased high-density lipoprotein cholesterol (p = 0.008) and increased C-reactive protein (CRP) (p < 0.001), while miR-21 correlated with lower total cholesterol (p = 0.024) and CRP (p < 0.001) in CHD patients. As stenosis degree, lnc-GAS5 positively correlated with Gensini score (p < 0.001), but miR-21 exhibited negative association (p = 0.003) in CHD patients. In terms of inflammatory cytokines, lnc-GAS5 positively related to tumor necrosis factor α (TNF-α) and interleukin (IL)-17A, while miR-21 negatively linked with TNF-α, IL-1ß, IL-6, and IL-17 in CHD patients (all p < 0.05). CONCLUSION: Circulating lnc-GAS5 and its target miR-21 exhibit potency to serve as biomarkers for CHD management.

LncRNA GAS5 relates to Th17 cells and serves as a potential biomarker for sepsis inflammation, organ dysfunctions and mortality risk.

BACKGROUND: Long noncoding RNA GAS5 (lnc-GAS5) is able to regulate macrophage M1 polarization and Th17 cell differentiation, also engaged in sepsis-induced inflammation and organ injury. This study aimed to further evaluate its linkage with Th1 cells and Th17 cells, as well as its clinical value in sepsis management. METHODS: About 101 sepsis patients were enrolled followed by peripheral blood mononuclear cell (PBMC) and serum samples collection. PBMC lnc-GAS5 was detected by RT-qPCR; Th1 cells and Th17 cells in PBMC CD4+ T cells were detected by flow cytometry; serum IFN-γ and IL-17A were detected by ELISA. Besides, PBMC lnc-GAS5 was also detected in 50 health controls (HCs). RESULTS: Lnc-GAS5 was reduced in sepsis patients than in HCs (p < 0.001), which also well-distinguished sepsis patients from HCs with AUC 0.860. Lnc-GAS5 did not relate to Th1 cells (p = 0.059) or IFN-γ (p = 0.192); while negatively linked with Th17 cells (p = 0.002) and IL-17A (p = 0.019) in sepsis patients. Interestingly, lnc-GAS5 negatively correlated with SOFA score (p = 0.001), SOFA-Respiratory system score (p = 0.001), SOFA-Coagulation score (p = 0.015), and SOFA-Renal system score (p = 0.026), but not SOFA-Liver score (p = 0.080), SOFA-Cardiovascular system score (p = 0.207) or SOFA-Nervous system score (p = 0.182) in sepsis patients. Furthermore, lnc-GAS5 was negatively related to CRP (p = 0.002) and APACHE II score (p = 0.004) in sepsis patients. Finally, lnc-GAS5 was decreased in dead sepsis patients compared to survivors (p = 0.007), which also distinguished sepsis deaths from survivors with AUC 0.713. CONCLUSION: Lnc-GAS5 relates to Th17 cells and serves as a potential biomarker for sepsis severity and mortality risk.

FoxO1 Silencing Facilitates Neurological Function Recovery in Intracerebral Hemorrhage Mice via the lncRNA GAS5/miR-378a-5p/Hspa5 Axis.

OBJECTIVE: Intracerebral hemorrhage (ICH) is the most devastating stroke subtype. Transcription factor Forkhead box O1 (FoxO1) is extensively implicated in cerebral injury. This study investigated the mechanism of FoxO1 in neurological function recovery in ICH mice. METHODS: A murine model of ICH was established. The modified neurological severity score (mNSS), forelimb placement test, and corner turn test were adopted to evaluate the neurological function of mice. The brain water content was measured and the pathological changes of cerebral tissues were observed. The levels of IL-1ß, IL-6, and TNF-α were determined. The expressions of FoxO1, lncRNA GAS5, miR-378a-5p, and heat shock 70 kDa protein 5 (Hspa5) in mouse cerebral tissues were examined. The binding relationships among FoxO1, lncRNA GAS5, miR-378a-5p, and Hspa5 were validated. Functional rescue experiments were designed to verify the role of lncRNA GAS5/miR-378a-5p/Hspa5 axis in neurological function recovery in ICH mice. RESULTS: FoxO1 was highly expressed in cerebral tissues of ICH mice. FoxO1 silencing facilitated neurological function recovery in ICH mice, evidenced by decreased mNSS, improved forelimb placement rate, reduced turning defects, declined brain water content, relieved edema, intracellular vacuoles, and inflammatory cell infiltration, and reduced IL-1ß, IL-6, and TNF-α levels. FoxO1 enhanced lncRNA GAS5 expression by binding to its promoter. LncRNA GAS5 facilitated Hspa5 transcription by sponging miR-378a-5p. Intervention of lncRNA GAS5/miR-378a-5p/Hspa5 axis reversed the promoting effect of FoxO1 silencing on the neurological function recovery in ICH mice. CONCLUSION: FoxO1 silencing facilitated neurological function recovery in ICH mice via the lncRNA GAS5/miR-378a-5p/Hspa5 axis.

Association of LncRNA-GAS5 gene polymorphisms and PBMC LncRNA-GAS5 level with risk of systemic lupus erythematosus in Chinese population.

Growth arrest-specific 5 (GAS5) is a kind of long non-coding RNAs (lncRNAs). Previous studies showed that down-regulation of LncRNA-GAS5 was involved in the development of systemic lupus erythematosus (SLE). However, the regulatory mechanism of down-expressed LncRNA-GAS5 in SLE remains obscure. In this study, we aimed to investigate the association of LncRNA-GAS5 polymorphism with SLE risk. And further explore how LncRNA-GAS5 is involved in the occurrence of SLE. Here, we evaluated the relationship between the risk for the development of SLE and the 5-base pair (AGGCA/-) insertion/deletion (I/D) polymorphism (rs145204276) in the LncRNA-GAS5 promoter region. A custom 36-Plex SNPscan kit was used for genotyping the LncRNA-GAS5 polymorphisms. The LncRNA-GAS5 and miR-21 target prediction was performed using bioinformatics software. Enzyme-linked immunosorbent assay (ELISA) and quantitative real-time PCR (qRT-PCR) were performed to assess GAS5 and miR-21 mRNA expression and PTEN protein expression. The results revealed that rs145204276 resulted in a decreased risk of SLE (DD genotypes vs II genotypes: adjusted OR = 0.538, 95% CI, 0.30-0.97, P = .039; ID genotypes vs II genotypes: adjusted OR = 0.641, 95% CI, 0.46-0.89, P = .007; ID/DD genotypes vs II genotypes: adjusted OR = 0.621, 95% CI, 0.46-0.84, P = .002; D alleles vs I alleles: adjusted OR = 0.680, 95% CI, 0.53-0.87, P = .002). A reduced incidence of renal disorders in SLE was found to be related to ID/DD genotypes and D alleles (ID/DD genotypes vs II genotypes: OR = 0.57, 95% CI, 0.36-0.92, P = .020; D alleles vs I alleles: OR = 0.63, 95% CI, 0.43-0.93, P = .019). However, no significant association of rs2235095, rs6790, rs2067079 and rs1951625 polymorphisms with SLE risk was observed (P > .05). Additionally, haplotype analysis showed that a decreased SLE risk resulted from the A-A-C-G-D haplotype (OR = 0.67, 95% CI, 0.49-0.91, P = .010). Also, patients in the SLE group showed a down-regulated expression of LncRNA-GAS5 and PTEN than the healthy volunteers; however, patients with rs145204276 ID/DD genotypes showed up-regulated expression of LncRNA-GAS5 and PTEN compared with patients carrying the II genotype. Furthermore, the miR-21 levels were considerably up-regulated in the SLE group than the healthy volunteers, and patients with rs145204276 ID/DD genotype had lower miR-21 levels than the ones with the II genotype. Thus, we found that the LncRNA-GAS5/miR-21/PTEN signalling pathway was involved in the development of SLE, where LncRNA-GAS5 acted as an miR-21 target, and miR-21 regulated the expression of PTEN. These findings indicated that the rs145204276 ID/DD genotypes in the LncRNA-GAS5 gene promoter region may be protected against SLE by up-regulating the expression of LncRNA-GAS5, which consecutively regulated miR-21 and PTEN levels.

lncRNA GAS5 suppresses rheumatoid arthritis by inhibiting miR-361-5p and increasing PDK4.

Rheumatoid arthritis (RA) is an inflammatory disease that causes hyperplasia of synovial tissue and cartilage destruction. This research was to investigate the effects of lncRNA GAS5/miR-361-5p/PDK4 on rheumatoid arthritis. By qRT-PCR, GAS5 and PDK4 were found to be overexpressed in synovial tissue, fibroblast-like synoviocytes of RA patients and LPS-induced chondrocytes, while the miR-361-5p expression was significantly reduced. GAS5 overexpression resulted in a decrease in the proliferation and Bcl-2 protein expression, and an increase in the Bax protein level. On the contrary, miR-361-5p sponged by GAS5 could accelerate chondrocyte proliferation, inhibit apoptosis. PDK4 targeted by miR-361-5p could inhibit RA, and partially eliminated the effect of miR-361-5p on RA. Our study suggested that GAS5 suppressed RA by competitively adsorbing miR-361-5p to modulate PDK4 expression.

Circulating Long Non-Coding RNA GAS5: A Non-Invasive Molecular Marker for Prognosis, Response to Treatment and Survival in Non-Small Cell Lung Cancer.

Circulating long non-coding RNAs (lncRNA) are dysregulated in several diseases, especially cancers, e.g. non-small-cell lung cancer (NSCLC). Of specific notice in this regard is growth arrest-specific 5 gene (lncRNA GAS5), which is principally recognised as a tumor suppressor gene in numerous cancers. Functionally, GAS5 is involved in arresting cellular growth and induction of apoptosis. We analysed plasma GAS5 expression by qRT-PCR in 100 patients with NSCLC before and after tumour resection surgery. We reported a downregulation of GAS5 expression in NSCLC tissue and plasma, which showed elevation after surgery. Downregulation of GAS5 was associated with poor prognosis of NSCLC patients.

Long non-coding RNA GAS5 suppresses rheumatoid arthritis progression via miR-128-3p/HDAC4 axis.

Rheumatoid arthritis (RA) is a highly relevant public health problem. RA fibroblast-like synoviocytes (RAFLSs) play an important role in RA progression. Long non-coding RNA growth arrest-specific transcript 5 (GAS5) could improve RA by inducing RAFLSs apoptosis. However, the mechanism of GAS5 in RA remains unclear. RT-qPCR detected the expressions of GAS5, microRNA-128-3p (miR-128-3p), and histone deacetylase 4 (HDAC4) in RA synovial tissues and RAFLSs. Proliferation, apoptosis, migration, and invasion were measured by Cell Counting Kit-8 assay (CCK-8), flow cytometry, and transwell assays, severally. The protein levels of B-cell lymphoma-2 (Bcl-2), C-caspase 3, Bcl-2 related X protein (Bax), Tumor Necrosis factor-α (TNF-α), Interleukin 6 (IL-6), Interleukin 17 (IL-17), HDAC4, phosphorylation-protein kinase B (p-AKT), AKT, a phosphorylation-mechanistic target of rapamycin (p-mTOR), and mTOR were assessed by western blot assay. The interaction between miR-128-3p and GAS5 or HDAC4 was predicted by ENCORI or TargetScan Human and verified by the dual-luciferase reporter, RNA Immunoprecipitation (RIP), and RNA pull-down assays. GAS5 and HDAC4 were downregulated, and miR-128-3p was upregulated in RA synovial tissues and RAFLSs. Function analysis indicated that GAS5 curbed proliferation, migration, invasion, inflammation, and facilitated apoptosis of RAFLSs. Rescue assay confirmed that miR-128-3p overexpression or HDAC4 knockdown weakened the inhibitory effect of GAS5 or anti-miR-128-3p on RA development. GAS5 acted as a miR-128-3p sponge to upregulate HDAC4 expression. Besides, GAS5/miR-128-3p/HDAC4 axis regulated RA progression partially through the AKT/mTOR pathway. Our studies disclosed that GAS5 restrained inflammation in synovial tissue partly through regulating HDAC4 via miR-128-3p, suggesting a potential lncRNA-targeted therapy for RA treatment.

Qingda granule exerts neuroprotective effects against ischemia/reperfusion-induced cerebral injury via lncRNA GAS5/miR-137 signaling pathway.

Background: Ischemic stroke is the second leading cause of death and disability worldwide, which needs to develop new pharmaceuticals for its prevention and treatment. Qingda granule (QDG), a traditional Chinese medicine formulation, could improve angiotensin II-induced brain injury and decrease systemic inflammation. In this study, we aimed to evaluate the neuroprotective effect of QDG against ischemia/reperfusion-induced cerebral injury and illustrate the potential mechanisms. Methods: The middle cerebral artery occlusion/reperfusion (MCAO/R) surgery in vivo and oxygen-glucose deprivation/reoxygenation (OGD/R) in vitro models were established. Ischemic infarct volume was quantified using magnetic resonance imaging (MRI). Neurobehavioral deficits were assessed using a five-point scale. Cerebral histopathology was determined by hematoxylin-eosin (HE) staining. Neuronal apoptosis was evaluated by TUNEL and immunostaining with NeuN antibodies. The protective effect of QDG on OGD/R-injured HT22 cells was determined by MTT assay and Hoechst 33258 staining. The expression of lncRNA GAS5, miR-137 and apoptosis-related proteins were investigated in MCAO/R-injured rats and in OGD/R-injured HT22 cells using RT-qPCR and western blot analysis. Results: QDG significantly reduced the ischemic infarct volume, which was accompanied with improvements in neurobehavioral deficits. Additionally, QDG significantly ameliorated cerebral histopathological changes and reduced neuron loss in MCAO/R-injured rats. Moreover, QDG improved growth and inhibited apoptosis of HT22 cells injured by OGD/R in vitro. Finally, QDG significantly decreased the expression of lncRNA GAS5, Bax and cleaved caspase3, whereas it increased miR-137 and Bcl-2 expression in MCAO/R-injured rats and in OGD/R-injured HT22 cells. Conclusion: QDG plays a neuroprotective role in ischemic stroke via regulation of the lncRNA GAS5/miR-137 signaling pathway.

LncRNA GAS5 sponges miR-362-5p to promote sensitivity of thyroid cancer cells to 131 I by upregulating SMG1.

This study aims to investigate the role of lncRNA growth arrest-specific transcript 5 (GAS5)/miR-362-5p/suppressor of morphogenesis in the genitalia 1 (SMG1) axis in 131 I-resistance in thyroid cancer (TC). GAS5, miR-362-5p, and SMG1 expression in TC tissues was assessed and the 131 I-resistant TC cells were established, which were treated with altered GAS5, miR-362-5p, and SMG1. The proliferation and apoptosis of 131 I-resistant TC cells were detected, and the expression of Akt/mTOR signaling pathway-related proteins was assessed. Binding relations between GAS5 and miR-362-5p, and miR-362-5p and SMG1 were confirmed. The role of GAS5 in 131 I-resistant TC cell growth in vivo was observed. GAS5 was downregulated and miR-362-5p was upregulated in TC tissues and 131 I-resistant cells. The 131 I-resistant TC cells had enhanced proliferation and repressed apoptosis, and the Akt/mTOR signaling pathway was activated. Overexpressed GAS5 strengthened 131 I sensitivity and suppressed TC cell growth, while upregulated miR-362-5p had an opposite effect. MiR-362-5p upregulation reversed the effect of GAS5, and SMG1 overexpression eliminated the impact of miR-362-5p upregulation on 131 I-resistant TC cells. GAS5 competitively binds to miR-362-5p and SMG1 is targeted by miR-362-5p. GAS5 sponges miR-362-5p to promote sensitivity of TC cells to 131 I by upregulating SMG1 and inactivating Akt/mTOR signaling pathway.

Long non-coding RNA GAS5, by up-regulating PRC2 and targeting the promoter methylation of miR-424, suppresses multiple malignant phenotypes of glioma.

PURPOSE: Malignant gliomas remain significant challenges in clinic and pose dismal prognosis on patients. In this study, we focused on growth arrest-specific 5 (GAS5), a tumor suppressive long non-coding RNA in glioma, explored its crosstalk with miR-424, and examined their biological functions in glioma. METHODS: Expressions of GAS5 and miR-424 were measured using qRT-PCR. The regulation of GAS5 on miR-424 expression was examined in GAS5-overexpressing glioma cells by combining methylation-specific PCR, western blotting, and RNA immunoprecipitation. Functional significance of GAS5 and miR-424 on in vitro cell proliferation, apoptosis, migration, invasion, and in vivo tumor growth was examined using colony formation, flow cytometry, wound healing, transwell assay, and the xenograft model, respectively. The potential targeting of AKT3 by miR-424 was investigated using luciferase reporter assay. RESULTS: GAS5 and miR-424 were significantly down-regulated in glioma cells. GAS5 directly interacted with enhancer of zeste homolog 2 (EZH2), stimulated the formation of polycomb repressive complex 2 (PRC2), reduced the levels of DNA methyltransferases (Dnmts), alleviated promoter methylation of miR-424, and promoted miR-424 expression. Functionally, GAS5, by up-regulating miR-424, inhibited cell proliferation, migration, and invasion, while increased apoptosis of glioma cells in vitro, and suppressed xenograft growth in vivo. miR-424 directly inhibited AKT3 and altered the expressions of AKT3 targets, cyclinD1, c-Myc, Bax, and Bcl-2, which might contribute to its tumor suppressive activities. CONCLUSIONS: GAS5, by inhibiting methylation and boosting expression of miR-424, inhibits AKT3 signaling and suppresses multiple malignant phenotypes. Therefore, stimulating GAS5/miR-424 signaling may benefit the treatment of glioma.

Long non-coding RNA GAS5 expression in patients with Down syndrome.

Trisomy 21, also known as Down Syndrome (DS), is the most common chromosome abnormality and causes intellectual disability. Long non-coding RNA (lncRNA) growth arrest-specific 5 (GAS5), whose differential expression has recently been reported in patients with Klinefelter syndrome, has been addressed to play a role in the development of inflammatory and autoimmune diseases, vascular endothelial cells apoptosis and atherosclerosis, all being common features in patients with DS. Therefore, the aim of this study was to assess the lncRNA GAS5 expression profile in DS patients and in controls. lncRNA GAS5 levels were evaluated by qRT-PCR assay in 23 patients with DS and 23 age-matched controls. A significant lncRNA GAS5 down-regulation was observed in patients with DS by RT-PCR analysis, The RNA sequencing experiments confirmed the qRT-PCR data. LncRNA GAS5 down-expression may play a role in the development of some typical features of the patients with DS and, particularly, in inflammatory and autoimmune diseases.

Association of genetic variants in lncRNA GAS5/miR-21/mTOR axis with risk and prognosis of coronary artery disease among a Chinese population.

BACKGROUND: Allowing for the significance of single nucleotide polymorphisms (SNPs) in reflecting disease risk, this investigation attempted to uncover whether SNPs situated in lncRNA GAS5/miR-21/mTOR axis were associated with risk and prognosis of coronary heart disease (CHD) among a Chinese Han population. METHODS: Altogether 436 patients with CHD were recruited as cases, and meanwhile, 471 healthy volunteers were included into the control group. Besides, SNPs of GAS5/MIR-21/mTOR axis were genotyped utilizing mass spectrometry. Chi-square test was applied to figure out SNPs that were strongly associated with CHD risk and prognosis, and combined effects of SNPs and environmental parameters on CHD risk were evaluated through multifactor dimensionality reduction (MDR) model. RESULTS: Single nucleotide polymorphisms of GAS5 (ie, rs2067079 and rs6790), MIR-21 (ie, rs1292037), and mTOR (rs2295080, rs2536, and rs1034528) were associated with susceptibility to CHD, and also Gensini score change of patients with CHD (P < .05). MDR results further demonstrated that rs2067079 and rs2536 were strongly interactive in elevating CHD risk (P < .05), while smoking, rs6790 and rs2295080 showed powerful reciprocity in predicting Gensini score change of patients with CHD (P < .05). CONCLUSION: Single nucleotide polymorphisms of lncRNA GAS5/miR-21/mTOR axis might interact with smoking to regulate CHD risk, which was conducive to diagnosis and prognostic anticipation of CHD.