LncR-GAS5 decrease in adenine phosphoribosyltransferase expresssion via binding TAF1 to increase kidney damage created by CIH.

Objective: Chronic kidney disease (CKD) related to obstructive sleep apnea-hypopnea syndrome (OSAHS) mainly results from chronic intermittent hypoxia (CIH)-induced renal injury. This study aimed to explore the interaction between the long noncoding RNA (lncRNA) growth arrest-specific transcript 5 (GAS5) and recombinant adenine phosphoribosyltransferase (APRT) in CIH-induced renal injury. Methods: A rat intermittent hypoxia model was constructed, total RNA was extracted from kidney tissue, and transcriptome sequencing was performed using high-throughput sequencing technology. CIH rat models were established and injected with sh-GAS5 or OE-APRT plasmid, the serum levels of blood urea nitrogen (BUN) and creatinine amidohydrolase were measured, and the expression of oxidative stress-related factors was detected. Hematoxylin and eosin (H&E) and Masson's trichrome staining were used for morphological observations, and cell apoptosis was determined by TUNEL staining. Interactions between GAS5, TATA-box binding protein-associated factor 1 (TAF1), and APRT were predicted and verified. After transfection of HK-2 cells, the expression of GAS5, TAF1, APRT, Bax, Bcl-2, apoptosis-related factors, fibrosis-related factors (collagen I and Ⅳ), and autophagy-related proteins (LC3-Ⅱ, LC3-Ⅰ, p62, and Beclin-1) was measured by RT-qPCR and western blotting. Results: Sequencing results revealed that TAF1 was significantly increased and APRT was significantly decreased in the CIH group. RNA was significantly involved in the biological process of kidney injury mediated by CIH. CIH rats injected with GAS5 suppression or APRT overexpression plasmids showed decreased GAS5 and elevated APRT expression, along with suppressed serum levels of BUN and creatinine amidohydrolase. Meanwhile, GAS5 suppression or APRT overexpression attenuated apoptosis and fibrosis, suppressed oxidative stress, and promoted autophagy in CIH-induced renal tubular epithelial cells. The RNA pull-down assay and RIP verified the binding and interaction of GAS5 and TAF1. Chip immunoprecipitation (ChIP) identified TAF1 regulation of the APRT promoter. GAS5 and TAF1 negatively regulated APRT expression. Conclusion: The lncRNA GAS5 can bind TAF1 to suppress APRT transcription, thereby enhancing CIH-induced renal injury in rats.

Resveratrol shields against cisplatin-induced ototoxicity through epigenetic lncRNA GAS5 modulation of miR-455-5p/PTEN pathway.

BACKGROUND: Our previous research demonstrated that resveratrol counters DDP-induced ototoxicity by upregulating miR-455-5p, which targets PTEN. This study aimed to elucidate the underlying mechanisms involving GAS5 and DNA methyltransferase 1 (DNMT1) in resveratrol's protective action. METHODS: A luciferase reporter assay and RNA immunoprecipitation (RIP) assay were employed to study the binding between GAS5 and miR-455-5p, as well as between miR-455-5p and PTEN. HEI-OC1 cells treated with DDP were transfected with vectors for GAS5, si-GAS5, DNMT1, si-DNMT1, and miR-455-5p mimics, as well as PTEN. Subsequently, they were treated with resveratrol and exposed to DDP, both separately and in combination. The distribution of CpG islands in the GAS5 promoter was identified using MethyPrimer, and methylation-specific PCR (MSP) was conducted to determine the methylation levels of GAS5. Chromatin immunoprecipitation (ChIP) was utilized to examine the interaction between DNMT1 and GAS5. The viability of HEI-OC1 cells, catalase (CAT) activity, apoptosis, and ROS levels were assessed using the CCK-8 assay, CAT assay, TUNEL staining, and flow cytometry, respectively. An in vivo mouse model was developed to measure auditory brainstem response (ABR) thresholds, while RT-qPCR and Western blot analysis were employed to evaluate molecular levels. RESULTS: Our study discovered that GAS5 acts as a sponge for miR-455-5p, thereby increasing PTEN expression in DDP-treated HEI-OC1 cells. This process was reversed upon treatment with resveratrol. Importantly, DNMT1 promoted the methylation of the GAS5 promoter, leading to the suppression of GAS5 expression. This suppression enhanced the effectiveness of resveratrol in combating DDP-induced apoptosis and ROS in HEI-OC1 cells and amplified its protective effect against DDP's ototoxicity in vivo. CONCLUSIONS: Our research emphasizes the significance of the DNMT1/GAS5/miR-455-5p/PTEN axis as a promising new route to boost resveratrol's effectiveness against DDP-induced ototoxicity.

Bone marrow mesenchymal stem cells-derived exosomal lncRNA GAS5 mitigates heart failure by inhibiting UL3/Hippo pathway-mediated ferroptosis.

BACKGROUND: Exosomes (Exos) are involved in the therapeutic effects of bone marrow mesenchymal stem cells (BMSCs) on heart failure (HF). We investigated the molecular mechanisms underlying the involvement of BMSC-Exos in ferroptosis on HF. METHODS: A rat model of HF and cellular model of hypoxia were established. BMSC-Exos were injected into model rats or co-cultured with model cells. In model rats, the cardiac function (echocardiography), oxidative stress (commercial kits), pathological damage (HE staining), fibrosis (MASSON staining), iron deposition (Prussian blue staining), and cell apoptosis (TUNEL staining) were examined. Viability (cell counting kit-8; CCK-8), cell cycle (flow cytometry), oxidative stress, and Fe2+ levels were detected in the model cells. GAS5, UL3, YAP, and TAZ expression were detected using qRT-PCR, western blotting, and immunohistochemistry analyses. RESULTS: BMSC-Exos restored cardiac function and inhibited oxidative stress, apoptosis, pathological damage, fibrosis, and iron deposition in myocardial tissues of HF rats. In hypoxic cells, BMSC-Exos increased cell viability, decreased the number of G1 phase cells, decreased Fe2+ levels, and inhibited oxidative stress. Ferrostatin-1 (a ferroptosis inhibitor) exhibited a synergistic effect with BMSC-Exos. Additionally, GAS5 was upregulated in BMSC-Exos, further upregulating its target UL3 and Hippo pathway effectors (YAP and TAZ). The relieving effects of BMSC-Exos on HF or hypoxia-induced injury were enhanced by GAS5 overexpression, but weakened by UL3 silencing or verteporfin (a YAP inhibitor). CONCLUSIONS: GAS5-harbouring BMSC-Exos inhibited ferroptosis by regulating the UL3/Hippo pathway, contributing to HF remission in vivo and in vitro.

Bulk and single-cell transcriptome profiling identify potential cellular targets of the long noncoding RNA Gas5 in renal fibrosis.

The long noncoding RNA growth arrest-specific 5 (lncRNA Gas5) is implicated in various kidney diseases. In this study, we investigated the lncRNA Gas5 expression profile and its critical role as a potential biomarker in the progression of chronic kidney disease. Subsequently, we assessed the effect of lncRNA Gas5 deletion on renal fibrosis induced by unilateral ureteral obstruction (UUO). The results indicated that loss of lncRNA Gas5 exacerbates UUO-induced renal injury and extracellular matrix deposition. Notably, the deletion of lncRNA Gas5 had a similar effect on control mice. The fibrogenic phenotype observed in mice lacking lncRNA Gas5 correlates with peroxisome proliferator-activated receptor (PPAR) signaling pathway activation and aberrant cytokine and chemokine reprogramming. Single-cell RNA sequencing analysis revealed key transcriptomic features of fibroblasts after Gas5 deletion, revealing heterogeneous cellular states suggestive of a propensity for renal fibrosis. Our findings indicate that lncRNA Gas5 regulates the differentiation and activation of immune cells and the transcription of key genes in the PPAR signaling pathway. These data offer novel insights into the involvement of lncRNA Gas5 in renal fibrosis, potentially paving the way for innovative diagnostic and therapeutic targets.

GAS5 regulated by FTO-mediated m6A modification suppresses cell proliferation via the IGF2BP2/QKI axis in breast cancer.

BACKGROUND: The lncRNA growth arrest-specific 5 (GAS5) is involved in regulating breast cancer progression. In this study, we aimed to elucidate the function and mechanism of GAS5 in breast cancer. METHODS: The expressions of GAS5, fat mass and obesity-associated protein (FTO), insulin-like growth factor 2 mRNA-binding protein 2 (IGF2BP2), and Quaking (QKI) were assessed by quantitative reverse transcription-polymerase chain reaction (qRT-PCR) and western blot. The m6A modification level of GAS5 was detected using m6A immunoprecipitation assay (MeRIP). The interaction between IGF2BP2 and GAS5 or QKI was detected using RNA immunoprecipitation assay (RIP) and dual luciferase reporter assay. Cell proliferation was measured using the Cell Counting Kit-8 (CCK-8) assay. The biological functions of the FTO/GAS5/IGF2BP2/QKI axis was assessed using the tumor xenograft assay. RESULTS: LncRNA GAS5 expression decreased in breast cancer and was regulated by FTO-mediated m6A modification in an IGF2BP2-dependent manner, resulting in decreased GAS5 stability and expression. GAS5 recruited IGF2BP2 to target QKI and upregulated QKI expression in breast cancer cells. GAS5 suppressed breast cancer growth via IGF2BP2/QKI, and this inhibitory effect was modulated by FTO both in vitro and in vivo. CONCLUSIONS: GAS5 regulated by FTO-mediated m6A modification represses the growth of breast cancer via the IGF2BP2/QKI pathway, suggesting that the FTO/GAS5/IGF2BP2/QKI pathway can be a potential target for breast cancer treatment.

LncRNA GAS5 Modulates the Progression of Glioma Through Repressing miR-135b-5p and Upregulating APC.

Purpose: The main purpose of this paper is to explore the interaction between GAS5 and miR-135b-5p to understand their function in the metastasis, invasion, and proliferation of glioma. This may provide new ideas for the pathogenesis and treatment of glioma. Patients and Methods: Western blotting assays and RT­qPCR were employed to investigate the expression of related genes in glioma tissues or cell lines. CCK-8 was used to examine the impact of GAS5 on cell viability. Motile activities were adopted by the transwell and wound healing experiments. A double luciferase experiment was performed to elucidate transcriptional regulation. Results: GAS5 showed low expression in glioma cells and tissues, and up-regulation of GAS5 could depress the invasion, proliferation, and metastasis of glioma. GAS5 negatively regulates miR-135b-5p, which can counteract the cellular effects caused by GAS5. APC was the target of miR-135b-5p, and GAS5 can regulate the expression of APC by sponging miR-135b-5p. APC overexpression reversed the effects of miR-135b-5p promotion on glioma cells, while miR-135b-5p has the opposite function. As a downstream target gene of GAS5, miR-135b-5p was negatively regulated by GAS5. The restoration of miR-135b-5p can remarkably reverse the impact of GAS5 on glioma cells. In addition, GAS5 increased the expression of APC in glioma cells by inhibiting miR-135b-5p. Conclusion: GAS5 increased APC expression by restraining miR-135b-5p and partially blocked the progression of glioma, suggesting that it could be an advantageous therapeutic target for glioma intervention.

Dexamethasone inhibits androgen receptor-negative prostate cancer cell proliferation via the GR-FOXO3a-GAS5 axis.

Background: Studies have shown that glucocorticoid receptor (GR) has inconsistent effects on the proliferation of prostate cancer cells, we found dexamethasone inhibited the proliferation of androgen receptor-negative prostate cancer cells, but the underlying mechanisms remain to be illustrated. Methods: GR expression and its prognosis role were analyzed based on the TCGA dataset. Bioinformatic analysis was performed to identify the candidate of GR downstream, which includes FOXO3a. After overexpressing FOXO3a in PC-3 cells, cell counting kit-8 (CCK-8) and migration assays were performed to evaluate cell proliferation and migration ability. Regulation of FOXO3a on GAS5 was also analyzed by JASPAR and PCR. Results: GR had low expression in prostate cancer and predicted poor prognosis. FOXO3a was identified as the downstream of GR to inhibit the proliferation of prostate cancer cells. Moreover, FOXO3a directly induces GAS5 expression, forming the GR-FOXO3a-GAS5 signaling pathway. Conclusion: Our study showed that GR played a role as a tumor suppressor gene in androgen receptor-negative prostate cancer cells via the GR-FOXO3a-GAS5 axis. Our results suggested patients with prostate cancer should be classified and develop a treatment plan according to the expression of AR and GR.

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.

GAS5, a long noncoding RNA, contributes to annulus fibroblast osteogenic differentiation and apoptosis in intervertebral disk degeneration via the miR-221-3p/SOX11 axis.

miR-221-3p has been reported to attenuate the osteogenic differentiation of annulus fibrosus cells (AFs), which has been implicated in intervertebral disk degeneration (IVDD) development. This study aimed to elucidate miR-221-3p's role in osteogenic differentiation and apoptosis of AFs in an IVDD model. After successfully establishing an IVDD rat model by annulus fibrosus needle puncture, AFs were isolated. Bioinformatics, dual-luciferase reporter, and AGO2-RNA immunoprecipitation (RIP) assays predicted and confirmed the potential miR-221-3p lncRNA and gene target. Functional analyses were performed after AF transfection to explore the roles of the identified lncRNA and gene. Western blotting, Alkaline phosphatase (ALP), and Alizarin red and TUNEL staining were performed to investigate AF apoptosis and osteogenic differentiation with different transfections. Compared with AFs isolated from sham rats, IVDD-isolated Afs exhibited stronger osteogenic potential and higher apoptosis rates accompanied by miR-221-3p downregulation. The growth arrest-specific transcript 5 (GAS5) was identified as miR-221-3p's target lncRNA, which was highly expressed in IVDD. GAS5 overexpression facilitated AF apoptosis and osteogenic differentiation, whereas silencing GAS5 had the opposite effect. SRY box-related11 (SOX11) was identified as a downstream miR-221-3p target gene in IVDD. GASS silencing-induced suppression of AF apoptosis and osteogenic differentiation could be reversed by SOX11 overexpression. Our findings uncovered a lncRNA GAS5/miR-221-3p/SOX11 axis in Afs under IVDD, which may help implement novel IVDD therapeutic strategies.

Electroacupuncture Promotes Nerve Regeneration and Functional Recovery Through Regulating lncRNA GAS5 Targeting miR-21 After Sciatic Nerve Injury.

Although the benefits of electroacupuncture (EA) for peripheral nerve injury (PNI) are well accepted in clinical practice, the underlying mechanism remains incompletely elucidated. In our study, we observed that EA intervention led to a reduction in the expression of the long non-coding RNA growth-arrest-specific transcript 5 (GAS5) and an increased in miR-21 levels within the injured nerve, effectively promoting functional recovery and nerve regeneration following sciatic nerve injury (SNI). In contrast, administration of adeno-associated virus expressing GAS5 (AAV-GAS5) weakened the therapeutic effect of EA. On the other hand, both silencing GAS5 and introducing a miR-21 mimic prominently enhanced the proliferation activity and migration ability of Schwann cells (SCs), while also inhibiting SCs apoptosis. On the contrary, inhibition of SCs apoptosis was found to be mediated by miR-21. Additionally, overexpression of GAS5 counteracted the effects of the miR-21 mimic on SCs. Moreover, SCs that transfected with the miR-21 mimic promoted neurite growth in hypoxia/reoxygenation-induced neurons, which might be prevented by overexpressing GAS5. Furthermore, GAS5 was found to be widely distributed in the cytoplasm and was negatively regulated by miR-21. Consequently, the targeting of GAS5 by miR-21 represents a potential mechanism through which EA enhances reinnervation and functional restoration following SNI. Mechanistically, the GAS5/miR-21 axis can modulate the proliferation, migration, and apoptosis of SCs while potentially influencing the neurite growth of neurons.

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.

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.

RBM38 Reverses Sorafenib Resistance in Hepatocellular Carcinoma Cells by Combining and Promoting lncRNA-GAS5.

BACKGROUND: Hepatocellular carcinoma (HCC) is a life-threatening human malignancy and the fourth leading cause of cancer-related deaths worldwide. Patients with HCC are often diagnosed at an advanced stage with a poor prognosis. Sorafenib is a multikinase inhibitor used as the first-line treatment for patients with advanced HCC. However, acquired resistance to sorafenib in HCC leads to tumor aggression and limits the drug's survival benefits; the underlying molecular mechanisms for this resistance remain unclear. METHODS: This study aimed to examine the role of the tumor suppressor RBM38 in HCC, and its potential to reverse sorafenib resistance. In addition, the molecular mechanisms underlying the binding of RBM38 and the lncRNA GAS5 were examined. The potential involvement of RBM38 in sorafenib resistance was examined using both in vitro and in vivo models. Functional assays were performed to assess whether RBM38: binds to and promotes the stability of the lncRNA GAS5; reverses the resistance of HCC to sorafenib in vitro; and suppresses the tumorigenicity of sorafenib-resistant HCC cells in vivo. RESULTS: RBM38 expression was lower in HCC cells. The IC50 value of sorafenib was significantly lower in cells with RBM38 overexpression than in control cells. RBM38 overexpression improved sorafenib sensitivity in ectopic transplanted tumors and suppressed the growth rate of tumor cells. RBM38 could bind to and stabilize GAS5 in sorafenib-resistant HCC cells. In addition, functional assays revealed that RBM38 reversed sorafenib resistance both in vivo and in vitro in a GAS5-dependent manner. CONCLUSIONS: RBM38 is a novel therapeutic target that can reverse sorafenib resistance in HCC by combining and promoting the lncRNA GAS5.

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.

lncRNA GAS5 suppression of the malignant phenotype of ovarian cancer via the miR-23a-WT1 axis.

Background: Growth arrest-specific 5 (GAS5) is a long noncoding RNA (lncRNA) that regulates cell viability. GAS5 lncRNA has been shown to decrease colorectal and breast cancer carcinogenesis. Although the function and mechanisms related to lncRNA GAS5 in the development of ovarian cancer (OC) remains unclear. The goal of this study was to clarify the essential functions of lncRNA GAS5 in regulating OC progression and its underlying mechanism. Methods: Relative levels of lncRNA GAS5 in OC and normal ovarian tissues were identified by quantitative real-time polymerase chain reaction (qRT-PCR). The regulatory effects of lncRNA GAS5 on the proliferation and apoptosis of SK-OV-3 cells were evaluated. Moreover, bioinformatics tools were used to predict a novel target [microRNA (miRNA)] of lncRNA GAS5. To explore the key functions of the lncRNA GAS5/miRNA-23a/WT1 regulatory loop in mediating OC progression, we performed functional experiments and a dual-luciferase reporter (DLR) gene assessment. Results: Downregulation of lncRNA GAS5 was found in tissues of OC, which was positively correlated with a poor prognosis. In addition, SK-OV-3 cells with a lower expression of lncRNA GAS5 and accelerated cancer cell migration demonstrated a lower percentage of apoptosis in in vitro experiments. It was demonstrated that lncRNA GAS5 acts as a molecular sponge for miR-23a in OC cells. Additionally, WT1 was detected as a miR-23a target gene in OC cells, and through sponging miR-23a, lncRNA GAS5 positively regulated WT1 expression. Rescue tests demonstrated that enhancing the outputs of the miR-23a-WT1 axis reversed the impacts of lncRNA GAS5 silencing on cell proliferation and apoptosis in OC. Conclusions: The lncRNA GAS5/miR-23a/WT1 cascade was found participate in the progression of OC. lncRNA GAS5 also decreases OC progression by upregulating WT1 and attenuating miR-23a, suggesting that it could be an advantageous therapeutic target for OC intervention.

Long non-coding RNA growth arrest-specific 5 inhibits liver fibrogenesis in biliary atresia by interacting with microRNA-222 and repressing IGF1/AKT signaling.

Background: Long non-coding RNA growth arrest-specific 5 (lncRNA GAS5) has been shown to inhibit liver fibrosis through serving as a competing endogenous RNA for microRNA-222 (miR-222). Progressive liver fibrosis is a typical characteristic of biliary atresia (BA). However, the role of GAS5/miR-222 and its underlying mechanisms remain largely unknown in BA. Methods: The expression of GAS5 was determined in the liver and primary hepatic stellate cells (HSCs) of BA patients. Then, the effects of GAS5 on the activation and proliferation of HSCs were evaluated. Furthermore, the interaction between GAS5 and miR-222 was investigated by a luciferase gene report assay. Next, the effects of IGF1/AKT signaling were determined to clarify the downstream mechanism of GAS5. Finally, GAS5 administration was performed to explore its role in an experimental BA mouse model. Results: GAS5 expression was decreased in liver tissues and HSCs of BA patients, and was inversely correlated with liver fibrosis in BA. Up-regulation of GAS5 in LX-2 cells significantly reduced smooth muscle α-actin (α-SMA) and collagen 1a1 (COL1A1) expression, inhibited cell proliferation and clone formation ability, induced S phase increase, and promoted cell apoptosis. Moreover, GAS5 was negatively regulated by miR-222, which promoted HSCs activation and proliferation, and was positively correlated with liver fibrosis in BA. Additionally, the expressions of IGF1, p-PI3K, and p-AKT were decreased when LX-2 cells over-expressed GAS5, whereas knockdown of IGF1 or AKT significantly decreased α-SMA and COL1A1 expression, suppressed cell proliferation, and enhanced cell apoptosis in LX-2 cells. Furthermore, GAS5 administration significantly increased apoptosis and reduced liver fibrosis, α-SMA and COL1A1 expressions in liver tissues of BA mice. Conclusions: GAS5 inhibited liver fibrosis in BA by interacting with miR-222 and regulating IGF1/AKT signaling, which may be a therapeutic target to alleviate liver fibrosis in BA.

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.

Sodium hydrosulfide and bone marrow derived mesenchymal stem cells combined therapy for bleomycin induced pulmonary fibrosis in rats: Implication of micro RNA-21 and Lnc GAS5.

AIMS: Pulmonary fibrosis (PF) is considered as an end stage for many lung diseases. Mesenchymal stem cells (MSC) as regenerative therapy have become a remarkably valuable therapeutic strategy in different diseases. Hydrogen sulfide has been recently introduced into the medical field for its antifibrotic properties in addition to enhancement of MSC stemness and function. The aim of the present study was to investigate the ability of BM-MSC in combination with NaHS to attenuate Bleomycin induced pulmonary fibrosis was studied in rats. A special emphasis was given to miR-21 and GAS5 as important players in the development of PF. MAIN METHODS: PF was induced in 32 Wistar male rats by single endotracheal injection of bleomycin, those were randomly divided into four groups (8 rats each): (untreated PF group) - (PF + MSC) treated group- (PF + NaHS treated group) - PF + combined (NAHS + MSC) treated group. KEY FINDINGS: Induction of PF was associated with increased miR-21 and decreased lncRNA-GAS5 expression. Treatment with either NaHS or BM-MSC leads to an inhibitory effect on pulmonary fibrosis as evidenced by improvement of histopathological studies, pulmonary function tests, reduction of inflammatory and fibrotic markers like Hydroxyproline, TNF α, TGF-ß and caspase -3 together with downregulation miR-21 and increase lncRNA-GAS5 expression. SIGNIFICANCE: The current work revealed the inhibitory effect of combined NaHS and BM-MSC on pulmonary fibrosis with concomitant modulation of miR-21 and lncRNA-GAS5 expression.

Histone demethylase KDM3C regulates the lncRNA GAS5-miR-495-3p-PHF8 axis in cardiac hypertrophy.

Cardiac hypertrophy (CH) is a pathological phenotype of cardiomyopathy. Epigenetic modification is a mechanism associated with CH. Our study here investigated the histone demethylase KDM3C in relation to epigenetic regulation in CH. We found that KDM3C mRNA silencing alleviated CH, as evidenced by reduced ANP, BNP, and ß-MHC mRNAs, increased α-MHC mRNA, decreased cell surface area, and reduced cellular protein/DNA ratios. Specifically, KDM3C upregulated miR-200c-3p expression through demethylation of H3K9me2, leading to enhanced binding of miR-200c-3p to GAS5 and suppression of GAS5 expression; these effects then led to reduced binding of GAS5 to miR-495-3p, increased miR-495-3p expression, and repression of PHF8 transcription. Through these mechanisms, our data indicate that KDM3C-dependent epigenetic modification promotes CH.

Gas5 inhibition promotes the axon regeneration in the adult mammalian nervous system.

Neurons in the peripheral nervous system (PNS) have robust regenerative capacity after axon injury, but the regenerative capacity is generally absent in the neurons of the central nervous system (CNS) in mammals. Increasing evidence highlighted the pivotal roles of long-noncoding RNAs (lncRNAs) in development and disease, but the role of LncRNA in triggering the regenerative capacity in CNS and PNS is not well studied. Here, we reported that lncRNA Gas5 is a suppressor for axon regeneration. Bioinformatics analysis shows that Gas5 is age-dependent up-regulated during DRG neurons development and down-regulated after sciatic nerve injury. In vitro, inhibiting the expression of Gas5 promotes the neurite growth of DRG neurons both in mice and rats. Consistently, Gas5 overexpression inhibits axon growth of mice DRG neurons. In vivo, Gas5 knockout(Gas5-/-) mice display enhanced nerve regeneration ability after sciatic nerve injury. RNA pull-down analysis indicates that Gas5 can interacts with soluble Vimentin, which is essential for peripheral nerve development and regeneration. Vimentin knockdown reverses the Gas5 silence-regulated axon pro-regeneration demonstrating that the function of Gas5 depending on Vimentin. Besides, inhibition of Gas5 expression can also enhance optic nerve regeneration indicating a potential pro-regenerative ability of Gas5 silence in CNS. Our study for the first time provides direct evidence in vivo that lncRNA plays a role in regulating central axon regrowth and Gas5 might be a novel therapeutic target for axon regeneration in both PNS and CNS.