GAS5 Expression Research Articles

LncRNA GAS5 alleviates rheumatoid arthritis through regulating miR-222-3p/Sirt1 signalling axis

Introduction Rheumatoid arthritis (RA) is an autoimmune disease that affects millions of people. Fibroblast-like synoviocytes (FLSs) located in rheumatoid panni play a pivotal role in the formation of RA. The long noncoding RNA (lncRNA) GAS5 is reportedly downregulated in rheumatoid arthritis. However, its detailed mechanism in RA remains to be explored. This study investigated the roles and related mechanisms of GAS5 in RA. Methods The expression levels of GAS5, miR-222-3p, and sirtuin 1 (Sirt1) were evaluated by quantitative PCR (qPCR). Cell proliferation was analyzed by CCK-8 and BrdU assays. Cell apoptosis was assessed by flow cytometry and western blotting. Enzyme-linked immunosorbent assay (ELISA) was utilized to evaluate the levels of TNF-α, IL-1β, and IL-6. The interaction between GAS5 or Sirt1 and miR-222-3p was predicted by starBase and validated by dual-luciferase reporter assay. Results GAS5 expression was found to be downregulated in the serum samples of RA patients and in RA-FLSs. GAS5 overexpression or the inhibition of miR-222-3p impeded the activity of RA-FLSs by repressing their proliferation and inflammation and by promoting apoptosis. Mechanistically, GAS5 indirectly regulates Sirt1 expression by binding miR-222-3p. Further experiments confirmed that Sirt1 overexpression restored the anti-RA activity of GAS5 under miR-222-3p mimic. Conclusions The miR-222-3p/Sirt1 axis was found to be critical for the function of GAS5 in regulating the proliferation, inflammation, and apoptosis of RA-FLSs. These data indicate GAS5 activation as a potential therapeutic strategy for RA progression.

LncRNA gas5 regulates granulosa cell apoptosis and viability following radiation by x-ray via sponging miR-205- 5p and Wnt/β-catenin signaling pathway in granulosa cell tumor of ovary

Purpose: To investigate the role of lncRNA gas5 in ovarian granulosa cells exposed to x-ray in granulosa cell tumor of ovary (GCTO).
 Methods: KGN cell line was exposed to X-ray to mimic the radiotherapy for GCSO patients in vitro, cell viability was checked by CCK8 assays. RNA expression of apoptosis-related genes was determined by quantitative reverse transcriptase-polymerase reaction (qRT-PCR) while Western Blot for biomarkers in wnt/β-catenin signaling. Differential expressions of lncRNA gas5 were examined after cells were exposed to a ray for 0,24,48hs. We over expressed gas5 and assessed resultant cell viability, apoptosis and signaling. The sponging between gas5 and miR-205-5p was verified by luciferase assay. CCK8, qRT-PCR and Western blot were applied to investigate the correlation between miR-205-5p, cell viability, and apoptosis after miR-205-5p augmentation. Similarly, interaction between gas5 and miR-205-5p was assessed after co-transfection of miR-205-5p mimics and oe-gas5. Finally, wnt inhibitor was used to study the role of signaling pathway in KGN cells.
 Results: Exposure of KGN to x-ray reduced cell viability and increased apoptosis. Gas5showed reduced expression in the cells, while miR-205-5p expression increased. Gas5 upregulation protected the cells against apoptosis and contributed to cell viability and activation of wnt//β-catenin signaling. lncRNA gas5 targeted miR-205-5p and miR-205-5p mimics counteracted the functions of up-regulated lncRNA gas5, regulating Wnt/β-catenin signaling pathway. Inactivation of Wnt/β-catenin suppressed cell viability.
 Conclusions: lncRNA gas5 regulates cell apoptosis and viability following cellular radiation, thus presenting a potential therapeutic target for the application radiotherapy in GCTO patients.
 Keywords: Ovary, Proliferation, Apoptosis, lncRNA gas5, Radiotherapy, β-catenin signaling

Exaggerated renal fibrosis in lncRNA Gas5-deficient mice after unilateral ureteric obstruction

AimsAbnormal expression of long non-coding RNAs (lncRNAs) occurs in several diseases including renal fibrosis. Notably, growth arrest-specific 5 (Gas5) is a lncRNA, which functions as an essential modulator of cell proliferation and growth. However, the role and expression of lncRNA Gas5 associated with renal fibrosis remains controversial. Herein, we investigate the effect of lncRNA Gas5 deficiency in renal fibrosis induced by the operation of unilateral ureteric obstruction (UUO) in mice. Main methodsSera and urine of mice were used to detect markers of renal function. Further, Masson and immunohistochemical staining, western blotting as well as qRT-PCR were performed to observe the distribution and expression of fibrosis marker in the kidney tissue of the mice. Key findingsUnlike the wild type mice, the obstructed kidney in Gas5+/− mice showed more severe renal fibrosis and collagen deposition. In the UUO-Gas5+/− group, the serum levels of uric acid, serum creatinine, and the urine levels of albumin-to-creatinine ratio were higher. Moreover, the expression of mRNA and protein of α-smooth muscle actin (α-SMA), vimentin, collagen IV, fibronectin, and matrix metalloproteinase 9 (MMP9) were higher, whereas that of phosphatase and tensin homolog (PTEN) were lower with the difference being statistically significant (p < 0.05). SignificancelncRNA Gas5 was up-regulated in renal fibrosis tissues, and its deficiency exacerbated renal fibrosis in the UUO mice model.

Cell Cycle Acceleration in Parathyroid Glands Is Caused by the Suppression of LncRNA Gas5 Expression in the Presence of a High-Phosphorus Diet in an Adenine-Induced CKD Rat Model

Cell Cycle Acceleration in Parathyroid Glands Is Caused by the Suppression of LncRNA Gas5 Expression in the Presence of a High-Phosphorus Diet in an Adenine-Induced CKD Rat Model

Down-regulation of lncRNA Gas5 promotes hypoxia-induced pulmonary arterial smooth muscle cell proliferation by regulating KCNK3 expression

Pulmonary hypertension (PH) is a progressive and potentially serious lung disease, defined by an abnormal elevation of pulmonary arterial pressure. PH occurs for many reasons, and hypoxia is considered as an important stimulus for the disease. Proliferation and migration of pulmonary artery smooth muscular cells (PASMCs) in the small peripheral pulmonary arteries are common characteristic features in hypoxia-induced PH (HPH). However, the mechanisms involved in the hypoxia-induced cell proliferation and migration are not clear. The aim of the present study was to investigate the role of lncRNA Gas5 in the hypoxia-stimulated proliferation and migration of human PASMCs (hPASMCs). We found that the expression of Gas5 was down-regulated in a rat model with hypoxia and in cultured hypoxic hPASMCs, and silence of Gas5 significantly promoted hPASMCs proliferation and migration in both normal and hypoxia condition. Subsequent studies revealed that miR-23b-3p interacted with Gas5 by directly targeting the miRNA-binding site in the Gas5 sequence, and qRT-PCR results showed miR-23b-3p and Gas5 could affect each other's expression, respectively. Further study demonstrated that Gas5 acted as a competing endogenous RNA (ceRNA) for miR-23b-3p to modulate the KCNK3 expression, and these interactions led to promotion of hPASMCs proliferation and migration. This study identified that Gas5/miR-23b-3p/KCNK3 axis may be a mechanism that hypoxia-induced PASMCs proliferation and migration, providing a strategy for clinical treatment of HPH in the future.

Long Non-coding RNA GAS5 Maintains Insulin Secretion by Regulating Multiple miRNAs in INS-1 832/13 Cells.

Type-2 diabetes mellitus (T2DM) is a complex disease characterized by reduced pancreatic islets β-cell mass and impaired insulin release from these cells. Non-coding RNAs, including microRNAs (miRNA) and long non-coding RNAs (lncRNAs), play a role in the progression of T2DM. Decreased serum lncRNA GAS5 levels were reported to be associated with T2DM. However, the role of GAS5 in regulating islet cell functions remain unknown. In this study, we found that the serum levels of GAS5 were significantly lower in patients with T2DM compared with healthy control subjects, and the low serum GAS5 levels were associated with high levels of HbAlc and fasting glucose in patients with T2DM. In addition, we found that serum GAS5 levels were negatively correlated with the serum levels of miR-29a-3p, miR-96-3p, and miR-208a-3p in patients with T2DM. Consequently, using INS-1 832/13 rat β-cell line, we found that overexpression of GAS5 by lentivirus infection increased glucose-stimulated insulin secretion and insulin content compared with negative control, whereas knockdown of GAS5 expression reduced both them. Moreover, GAS5 interacted with miR-29a-3p, miR-96-3p, and miR-208a-3p in INS-1 832/13 cells, as judged by pull-down assay and dual luciferase reporter assay. GAS5 overexpression caused the decrease in expression of miR-29a-3p, miR-96-3p, and miR-208a-3p in INS-1 832/13 cells and conversely caused the increase in expression of insulin receptor, insulin receptor substrate, and phosphoinositide-3-kinase regulatory subunit 1. Thus, these results reveal a novel mechanism whereby GAS5 is involved in maintaining insulin secretion and may represent a novel therapeutic target for T2DM.

RETRACTED: Low-expressed GAS5 injure myocardial cells and progression of chronic heart failure via regulation of miR-223-3P

Chronic heart failure (CHF) is a common disease in clinical practice, and its incidence has been increasing in recent years. Understanding the pathogenesis of CHF is the key to its future clinical diagnosis and treatment. Molecular research is a hot topic in modern hospitals, and long non-coding RNA (LncRNA) has been gradually understood and applied in many diseases. The situation of LncRNA GAS5 in CHF is still unclear, so this experiment will investigate the situation of GAS5 in CHF and its effect on myocardial cells, aiming to gain a preliminary understanding of the mechanism of GAS5's effect on CHF. In this study, the expression of GAS5 and miR-223-3p in peripheral blood of CHF patients and healthy subjects was first detected, GAS5 was low in CHF while miR-223-3p was high (P<0.05). Subsequently, ROC curve analysis showed that GAS5 and miR-223-3p had good predictive value for the occurrence and recurrence of CHF. Secondly, through in vitro experiments, we found that inhibition of GAS5 with elevated expression of miR-223-3p decreased the proliferative capacity of cardiomyocytes and increased apoptotic capacity and inflammatory factors (P<0.050). Through dual luciferase reporter and RNA immunoprecipitation experiment, we found that miR-223-3p was regulated by GAS5 in a targeted manner.

MeCP2 inactivation of LncRNA GAS5 triggers cardiac fibroblasts activation in cardiac fibrosis

Long non coding RNA growth arrest-specific transcript 5 (LncRNA GAS5) participate in the formation of fibrosis diseases. However, the key role of LncRNA GAS5 in the development of cardiac fibrosis remains unclear. Accumulating evidence suggests that DNA methylation alterations play a central role in cardiac fibroblast activation. In this study, we explored MeCP2 inactivation of LncRNA GAS5 leads to down regulation of LncRNA GAS5 expression in cardiac fibrosis. Gain and loss function of LncRNA GAS5 and MeCP2 was analyzed. The expression of LncRNA GAS5 was significantly decreased in cardiac fibrosis tissues, while MeCP2 was significantly increased. Moreover, the expression of MeCP2 was increased in TGF-β1 induced cardiac fibroblasts, while the expression of LncRNA GAS5 was decreased. Down regulation of LncRNA GAS5 resulted in increasing cellular proliferation. In contrast, exogenous over expression of LncRNA GAS5 in cardiac fibroblasts inhibited cell proliferation. 5-AzadC or knockdown of MeCP2 treatment significantly restored LncRNA GAS5 expression in cardiac fibroblasts, while over expression of MeCP2 treatment significantly inhibited LncRNA GAS5 expression in cardiac fibroblasts. In summary, these results suggested that MeCP2 silencing of LncRNA GAS5 triggers cardiac fibroblasts activation in cardiac fibrosis.

LncRNA GAS5 suppresses ER stress‑induced apoptosis and inflammation by regulating SERCA2b in HG‑treated retinal epithelial cell.

Hyperglycemia impairs the retinal functions in patients with diabetic retinopathy (DR). Downregulation of long non‑coding RNA growth arrest‑specific transcript 5 (lncRNA GAS5) expression in diabetes affects glucose intake and insulin signaling. Sarcoplasmic/endoplasmic reticulum Ca2+ ATPase 2 (SERCA2) mediates the regulation of endoplasmic reticulum (ER) stress and apoptosis in high glucose (HG)‑treated podocytes. Therefore, the present study aimed to investigate the roles of lncRNA GAS5 and SERCA2 in retinal pigment epithelium cells exposed to HG. GAS5 expression levels were detected using reverse transcription‑quantitative PCR. In addition, the expression levels of SERCA2b, ER stress‑related proteins, pro‑inflammatory factors and apoptotic proteins were determined by western blot analysis, ELISA or flow cytometry. The results showed that HG treatment induced ER stress in ARPE‑19 human adult retinal pigment epithelial cells by upregulating the expression levels of phosphorylated (p)‑protein kinase R‑like ER kinase, p‑eukaryotic initiation factor 2α, activating transcription factor 4 and CCAAT/enhancer‑binding protein homologous protein. In addition, HG treatment induced apoptosis by increasing Bax, Bad and caspase 12, and by decreasing Bcl‑2 levels expression levels. Moreover, HG treatment induced inflammation by upregulating tumor necrosis factor‑α, interleukin (IL)‑1β and IL‑6 expression. However, GAS5 and SERCA2b overexpression significantly decreased ER stress‑related apoptosis and inflammation, whereas SERCA2b knockdown significantly reversed the inhibitory effect of GAS5 on ER stress, apoptosis and inflammation. The results of the present study indicated that GAS5 may suppress ER stress‑induced apoptosis and inflammation by regulating SERCA2b in HG‑treated cells. These data suggested that GAS5 may serve a vital role in the pathogenesis of DR, and it may be considered a potential target for DR therapy.

Dysregulation of GAS5 and OIP5-AS1 lncRNAs in periodontitis

Periodontitis as a multifactorial disorder has been associated with dysregulation of several genes which contribute in regulation of immune responses. Recently, a number of studies have addressed the role of long non-coding RNAs (lncRNAs) in the pathogenesis of this disorder. In the current study, we evaluated expression of two lncRNAs, namely GAS5 and OIP5-AS1 in peripheral blood and tissues samples of patients with periodontitis and healthy subjects using quantitative real time PCR. Expression of GAS5 was significantly lower in blood samples obtained from patients with periodontitis compared with normal controls (Posterior beta of RE = −2.677, P value < 0.0001). When dividing study participants based on their gender, expression of this lncRNA was also lower in blood samples obtained from female patients compared with female controls (Posterior beta of RE = −3.22, P value = 0.006). However, the differences between male subgroups were insignificant. No significant difference was found in tissue expression of GAS5 between cases and controls. Besides, expression of OIP5-AS1 was significantly lower in blood samples of patients with periodontitis compared with normal controls (Posterior beta of RE = −1.794, P value = 0.015). When dividing study participants based on their gender, expression of OIP5-AS1 was lower in female patients compared with sex-matched controls (Posterior beta of RE = −1.901, P value = 0.032). Moreover, expression of this lncRNA was higher in female subjects compared with male subjects (Posterior beta of RE = 1.056, P value = 0.049). No significant correlation was found between expression of lncRNAs and age either between cases or controls. There were significant correlations between expressions of GAS5 and OIP5-AS1 both in affected tissues and in normal tissues (r = 0.51, P < 0.0001 and r = 0.73, P < 0.0001, respectively). Expression levels of these lncRNAs were correlated in blood samples of patients (r = 0.63, P value < 0.0001), but not healthy subjects (P = 0.29). Consequently, the results of the current study imply a possible role for these lncRNAs in the pathogenesis of periodontitis and warrants further functional investigations.

Epigenome-wide association study and multi-tissue replication of individuals with alcohol use disorder: evidence for abnormal glucocorticoid signaling pathway gene regulation

Alcohol use disorder (AUD) is a chronic debilitating disorder with limited treatment options and poorly defined pathophysiology. There are substantial genetic and epigenetic components; however, the underlying mechanisms contributing to AUD remain largely unknown. We conducted the largest DNA methylation epigenome-wide association study (EWAS) analyses currently available for AUD (total N = 625) and employed a top hit replication (N = 4798) using a cross-tissue/cross-phenotypic approach with the goal of identifying novel epigenetic targets relevant to AUD. Results show that a network of differentially methylated regions in glucocorticoid signaling and inflammation-related genes were associated with alcohol use behaviors. A top probe consistently associated across all cohorts was located in the long non-coding RNA growth arrest specific five gene (GAS5) (p < 10−24). GAS5 has been implicated in regulating transcriptional activity of the glucocorticoid receptor and has multiple functions related to apoptosis, immune function and various cancers. Endophenotypic analyses using peripheral cortisol levels and neuroimaging paradigms showed that methylomic variation in GAS5 network-related probes were associated with stress phenotypes. Postmortem brain analyses documented increased GAS5 expression in the amygdala of individuals with AUD. Our data suggest that alcohol use is associated with differential methylation in the glucocorticoid system that might influence stress and inflammatory reactivity and subsequently risk for AUD.

Role of Long Noncoding RNA Gas5 in Cocaine Action

BackgroundLong noncoding RNAs (lncRNAs) are a class of transcribed RNA molecules greater than 200 nucleotides in length. Although lncRNAs do not encode proteins, they play numerous functional roles in gene expression regulation. lncRNAs are notably abundant in brain; however, their neural functions remain largely unknown. MethodsWe examined the expression of the lncRNA Gas5 in nucleus accumbens (NAc), a key brain reward region, of adult male mice after cocaine administration. We then performed viral-mediated overexpression of Gas5 in NAc neurons to determine its role in addiction-related behaviors. We also carried out RNA sequencing to investigate Gas5-mediated transcriptomic changes. ResultsWe demonstrated that repeated short-term or long-term cocaine administration decreased expression of Gas5 in NAc. Viral-mediated overexpression of Gas5 in NAc neurons decreased cocaine-induced conditioned place preference. Likewise, Gas5 overexpression led to decreased cocaine intake, decreased motivation, and compulsive-like behavior to acquire cocaine, and it facilitated extinction of cocaine-seeking behavior. Transcriptome profiling identified numerous Gas5-mediated gene expression changes that are enriched in relevant neural function categories. Interestingly, these Gas5-regulated gene expression changes significantly overlap with chronic cocaine-induced transcriptome alterations, suggesting that Gas5 may serve as an important regulator of transcriptional responses to cocaine. ConclusionsAltogether, our study demonstrates a novel lncRNA-based molecular mechanism of cocaine action.

SAT-LB138 The LncRNA Growth Arrest Specific 5 Regulates Cell Survival via Distinct Structural Modules With Independent Functions

The growth arrest-specific 5 (gas5) gene encodes a long non-coding RNA (lncRNA) that is required for normal growth arrest, slows down the cell cycle, controls apoptosis, and is required for the inhibition of cell growth by mTOR inhibitors such as rapamycin. In agreement with this role in regulating cell proliferation, Gas5 expression is reduced and acts as a tumor suppressor in numerous cancers, including B-cell lymphoma and leukemia. At its 3’ terminal end (nucleotides 546-566) Gas5 contains a predicted stem-loop structure that specifically interacts with steroid receptors (SRs) and blocks DNA-dependent steroid signalling. In steroid-sensitive cancer cells such as prostate cancers this SR binding motif is responsible for Gas5 effects on cell growth. This is not true in other cell types, however, where proliferation is not strongly dependent on SR signaling (e.g. leukemic T cells). Therefore, other regions in Gas5 must be active and use different mechanisms to regulate cell survival. We have used SHAPE chemical probing to analyze the secondary structure of Gas5 in vitro and in cellulo. We find that the secondary structure of endogenous Gas5 resembles that of in vitro transcribed Gas5 RNA. The molecule contains three separate structural modules: a 5’ module with low secondary structure content, a highly structured core module, and the SR binding module, which forms separate from the rest of the molecule close to its 3’ end. Functional studies in leukemic T cells show that the 5’ module mediates Gas5’s role in inhibiting basal cell survival and slowing the cell cycle, whereas the core module is required for mediating the effects of mTOR inhibition. These results confirm that the Gas5 structural modules function independently in cells and each module acts under different cellular conditions, likely using different molecular mechanisms. RNA pull-downs from cell lysates using the identified modules and full-length RNA identified proteins preferentially associated with each module. Proteins preferentially associated with the 5’ terminal region are enriched in splicing and RNA processing factors. The structured central region preferentially interacts with proteins involved in chromosome organization such as the SWI/SNF family of nucleosome remodeling complexes.

LncRNA GAS5 affects epithelial-mesenchymal transition and invasion of breast cancer cells by regulating miR-216b.

To study the mechanism of lncRNA GAS5 affecting epithelial-mesenchymal transition and invasion of breast cancer cells by regulating miR-216b. Quantitative Real Time-Polymerase Chain Reaction (qRT-PCR) was used to detect the expressions of GAS5 and miR-216b in breast cancer and paracancerous tissues. The relationship between GAS5 and clinicopathological parameters of breast cancer patients was analyzed. The Dual-Luciferase reporter gene was used to detect the interaction between GAS5 and miR-216b and the transwell invasion assay was used to detect the invasive ability of lung cancer cells after GAS5 inhibition. Apoptosis assay was used to detect the apoptosis of breast cancer cells after GAS5 inhibition. Western blotting and immunofluorescence staining were used to detect the inhibition of GAS5 epithelial-mesenchymal transition. Compared with paracancerous tissues, in breast cancer tissues, the expression of GAS5 was increased and the expression of miR-216b was decreased. As the patients enter the later stages of breast cancer, the expression level of GAS5 in breast cancer patients was significantly elevated. The expression of GAS5 in the tissues with lymph node metastasis of breast cancer was markedly increased. The inhibition of GAS5 can promote the apoptosis of breast cancer cells; GAS5 can specifically bind to the 3' UTR of miR-216b. The expression of GAS5 inhibited the expression of E-cadherin in breast cancer cells and significantly upregulated N-cadherin, which has been confirmed by immunofluorescence staining experiments. GAS5 plays an important role in the development of breast cancer. GAS5 can target on miR-216b to regulate the biological behavior and epithelial-mesenchymal transition of breast cancer cells.

LncRNA GAS5 and miR-137 Polymorphisms and Expression are Associated with Multiple Sclerosis Risk: Mechanistic Insights and Potential Clinical Impact.

The pathogenesis of multiple sclerosis (MS) is influenced by the interaction of genetic and epigenetic mechanisms. The long noncoding RNA GAS5 acts as a competing endogenous RNA for microRNA-137 and is involved in demyelination. We investigated the association of GAS5 and miR-137 expression and their polymorphisms with MS susceptibility. One hundred and eight MS patients and 104 healthy controls were included. Expression analysis and genotyping of GAS5-rs2067079 and miR-137-rs1625579 single nucleotide polymorphisms were performed by qPCR. Serum GAS5 was upregulated, while serum miR-137 was downregulated in MS compared with the controls. Serum miR-137 was an excellent discriminator of MS patients from the controls (AUC = 0.97) and a negative independent predictor of MS in multivariate logistic analysis. Serum GAS5 expression was positively correlated with the expanded disability status scale scores in the relapsing-remitting MS patients. The rs2067079TT minor homozygote genotype was associated with an increased MS risk, while the rs1625579G minor allele was protective. rs1625579 showed an age-specific effect, while the rs2067079 affected the MS risk in gender- and age-specific manners. In MS patients, rs2067079TT was associated with a higher serum GAS5 than other genotypes, while serum miR-137 did not differ between rs1625579 genotypes. Our results suggest serum GAS5 and miR-137 as MS biomarkers, with miR-137 as a negative predictor of MS risk and GAS5 as a marker of MS severity. We propose rs2067079 and rs1625579 as novel genetic markers of MS susceptibility, and at least, rs2067079 possibly impacts the crosstalk between GAS5 and miR-137.

LncRNA-GAS5 regulates PDCD4 expression and mediates myocardial infarction-induced cardiomyocytes apoptosis via targeting MiR-21

ABSTRACT The present study was designed to investigate whether and how lncRNA-GAS5 regulates cardiomyocyte apoptosis in MI. MI rat model was established by the left anterior descending (LAD) coronary artery ligation. MI model was further evaluated by biomarkers detection and TUNEL, HE and Masson staining. The roles of lncRNA-GAS5 on hypoxia/reoxygenation (H/R)-induced cardiomyocytes survival, cell cycle arrest, and apoptosis were examined by MTT and flow cytometry in rat heart-derived H9c2 cells. Western blot was used to determine the effect of GAS5 on the expression of apoptosis-associated proteins and PI3 K/AKT signaling pathway. The direct bindings of GAS5 to miR-21 and miR-21 to PDCD4 were measured by dual-luciferase reporter assay or RNA immunoprecipitation. Decreased expressions of GAS5 and PDCD4 as well as increased miR-21 level were observed in the hearts of MI-modeled rat, accompanying with morphologically myocardial cell injury, as well as collagen deposition and fibrosis, and elevated levels of cTnl, CK, CK-MB and LDH. In the cell model, the knockdown of GAS5 promoted cell survival, prevented cell cycle arrest and inhibited cell apoptosis while the overexpression of GAS5 showed the opposite effects. GAS5 was found to downregulate miR-21 and the effects of GAS5 were attenuated by miR-21 mimics. GAS5 positively regulated PDCD4 expression by functioning as a sponge of miR-21 in H/R model. Moreover, GAS5 stimulated PDCD4 and suppressed PI3 K/AKT signal pathway. LncRNA-GAS5 regulates PDCD4 expression to mediate MI-induced cardiomyocyte apoptosis via targeting miR-21, suggesting that GAS5 could be a therapeutic target for MI.

Inhibition of cardiomyocyte differentiation of human induced pluripotent stem cells by Ribavirin: Implication for its cardiac developmental toxicity

Ribavirin has been proven to be an antiviral treatment, whereas there are still risks of hemolysis and congenital malformation. Abnormal cardiac development contributes to the occurrence and development of many heart diseases. However, there is so far no evidence that ribavirin induces human cardiac developmental toxicity. Herein, we employed the cardiac differentiation model of human induced pluripotent stem cells (hiPSCs) to determine the impact of ribavirin on heart development. Our data showed that ribavirin at clinically high concentrations (5 and 10 μM) significantly inhibited the proliferation and differentiation of hiPSCs from mesoderm to cardiac progenitor cells and cardiac progenitor cells to cardiomyocytes, but not from pluripotent status to mesoderm. Meanwhile, DCFH-DA staining revealed that ribavirin could increase ROS content in the mid-phase of differentiation. In addition, ribavirin treatment (1, 5 and 10 μM) remarkably caused DNA damage which was shown by the increase of γH2AX-positive cells and upregulation of the p53 during the differentiation of hiPSCs from mesoderm to cardiac progenitor cells. Moreover, exposuring to ribavirin (5 and 10 μM) markedly upregulated the expression of lncRNAs Gas5 in both mid-phase and late phase of differentiation and HBL1 in the mid-phase. In conclusion, our results suggest that ribavirin is detrimental in cardiac differentiation of hiPSCs, which may be associated with DNA damage, upregulated p53 and increased Gas5. It may provide the evidence for the rational clinical application of ribavirin.

Long non-coding RNA GAS5 regulates the growth and metastasis of human cervical cancer cells via induction of apoptosis and cell cycle arrest

Studies have proved the role of GAS5 in the development of different cancers. This study was undertaken to investigate the role and explore therapeutic implications of GAS5 in human cervical cancer. The results showed that GAS5 was significantly (p < 0.05) downregulated in human cervical cancer tissues. The results also showed that cervical cancer progresses with the suppression of GAS5 expression levels. Additionally, the expression of GAS5 was also significantly (p < 0.05) downregulated in human cervical cancer cell lines. Nonetheless, overexpression of GAS5 caused a remarkable decrease in the proliferation of C33A and HeLa cervical cancer cells. The decrease in the proliferation rate was attributed to the induction of apoptosis of C33A and HeLa cells which was accompanied with upregulation of Bax and suppression of Bcl-2. Additionally, GAS5 overexpression also promoted the arrest of C33A and HeLa cells at the G2/M check point of cell cycle via suppression of cyclin B1 and CDK1 expression. The transwell assays showed that GAS5 overexpression significantly (p < 0.05) inhibited the migration and invasion of the C33A and HeLa cervical cancer cells. The bioinformatics analysis as well as the dual luciferase assay showed GAS5 acts as a target of miR-135a. Interestingly, the expression of miR-135a was upregulated in the human cervical cancer cells and its suppression exerted growth inhibitory effects on the C33A and HeLa cells. However, silencing of GAS5 could nullify the effects of miR-135a suppression on the proliferation of C33A and HeLa cells. Taken together, the results of this study point towards the therapeutic implications of GAS5 in the treatment of cervical cancer.

Effects of small nucleolar RNA SNORD44 on the proliferation, apoptosis and invasion of glioma cells.

To master the effect of small nucleolar RNA, SNORD44, on the proliferation, apoptosis and invasion of glioma cells and its relevant mechanism. SNORD44 and GAS5 expression in glioma tissues and cells was detected through qRT-PCR. Then, the glioma cell lines (U87 and U251) were divided into different groups with different treatments. Cell proliferation was determined by MTT assay, while the abilities of the cell migration and invasion were measured by wound-healing test and Transwell assay, respectively. Cell apoptosis were detected by flow cytometry and TUNEL assay. The expression of apoptosis proteins was quantified through Western blotting. Finally, the xenograft models were established on nude mice to investigate the effects of SNORD44 on the growth of glioma and the expressions of Ki67, MMP2 and MMP9 in vivo. SNORD44 and GAS5 were down-regulated in glioma tissues and cells in a positive correlation. Either SNORD44 or GAS5 overexpression decreased the proliferation, invasion and migration of U87 and U251 cells with the up-regulation of apoptosis rates, as well as the expressions of cleaved PARP, caspase 3, caspase 8 and caspase 9. Moreover, the in vivo experiment showed that overexpression of SNORD44 blocked the growth of glioma xenograft in nude mice accompanying with the inhibition of Ki67, MMP2 and MMP9 expressions. The combination overexpression of SNORD44 and GAS5 gained better inhibitory effects on glioma cells. Overexpression of SNORD44 and GAS5 activate the caspase-dependent apoptosis pathway to facilitate the apoptosis with the inhibited proliferation, invasion and migration of glioma cells.

Aging and biomarkers: Transcriptional levels evaluation of Osteopontin/miRNA-181a axis in hepatic tissue of rats in different age ranges.

Osteopontin (OPN), a novel hepatic damage marker, as well as several non-coding RNA seem to be associated with liver aging, a little studied and not yet defined process. The aim of the study was to evaluate the expression variations of OPN and miRNA-181a, the transcriptional profiling of long non coding (lnc) RNA GAS-5/miRNA-222 axis and lncRNA NEAT-1 in liver tissue of rats. In addition, to monitor the senescence process, the telomere shortening and TERT/TERC gene expression were also measured. Three groups of male Wistar rats were studied: A (n=6, young); B (n=13, adult); C (n=10, old). Total RNA, including miRNAs, was extracted from liver and analysed by Real-Time PCR. Ultrasound and biochemical evaluation were performed in all rats as well as the histological analysis. OPN mRNA resulted lower in C with respect to A and B while miRNA-181a expression was significantly increased as a function of age. An increasing of both NEAT-1 and miRNA-222 expression as a function of age in parallel with a decreasing of GAS-5 expression in young and old rats, but not in the adults, was observed. A positive correlation was detected between miRNA-181a and miRNA-222. The hepatic ultrasound analysis revealed areas of hyperechogenicity distributed as a function of age. A significant telomere shortening was measured as a function of age while the two subunits TERT and TERC expressions showed an opposite trend. This work could provide a valid starting point to better understand the physiopathological changes during aging, pinpointing in the OPN/miRNA-181a axis significant predictors of successful aging.