Ablation of long noncoding RNA MALAT1 activates antioxidant pathway and alleviates sepsis in mice.
Ontology highlight
ABSTRACT:
SUBMITTER: Chen J
PROVIDER: S-EPMC9241053 | biostudies-literature |
REPOSITORIES: biostudies-literature
Similar Datasets
Project description:Recent studies suggest that in humans, DNA sequences responsible for protein coding regions comprise only 2% of the total genome. The rest of the transcripts result in RNA transcripts without protein-coding ability, including long noncoding RNAs (lncRNAs). Different from most members in the lncRNA family, the metastasis-associated lung adenocarcinoma transcript 1 (Malat1) is abundantly expressed and evolutionarily conserved throughout various mammalian species. Malat1 is one of the first identified lncRNAs associated with human disease, and cumulative studies have indicated that Malat1 plays critical roles in the development and progression of various cancers. Malat1 is also actively involved in various physiologic processes, including alternative splicing, epigenetic modification of gene expression, synapse formation, and myogenesis. Furthermore, extensive evidences show that Malat1 plays pivotal roles in multiple pathological conditions as well. In this review, we will summarize latest findings related to the physiologic and pathophysiological processes of Malat1 and discuss its therapeutic potentials.
| S-EPMC5731810 | biostudies-other
Project description:The study was designed to determine the role of long noncoding RNA (lncRNA), metastasis-associated lung adenocarcinoma transcript 1 (Malat1), in ischemic stroke outcome. Primary mouse brain microvascular endothelial cells (BMECs) were cultured and treated with Malat1 GapmeR before 16 h oxygen and glucose depravation (OGD). Cell death was assayed by LDH and MTT methods. Malat1 knock-out and wild-type mice were subjected to 1 h of middle cerebral artery occlusion (MCAO) and 24-72 h of reperfusion. To explore the underlying mechanism, apoptotic and inflammatory factors were measured by qPCR, ELISA, and Western blotting. The physical interaction between Malat1 and apoptotic or inflammatory factors was measured by RNA immunoprecipitation. Increased Malat1 levels were found in cultured mouse BMECs after OGD as well as in isolated cerebral microvessels in mice after MCAO. Silencing of Malat1 by Malat1 GapmeR significantly increased OGD-induced cell death and Caspase 3 activity in BMECs. Silencing of Malat1 also significantly aggravated OGD-induced expression of the proapoptotic factor Bim and proinflammatory cytokines MCP-1, IL-6, and E-selectin. Moreover, Malat1 KO mice presented larger brain infarct size, worsened neurological scores, and reduced sensorimotor functions. Consistent with in vitro findings, significantly increased expression of proapoptotic and proinflammatory factors was also found in the cerebral cortex of Malat1 KO mice after ischemic stroke compared with WT controls. Finally, we demonstrated that Malat1 binds to Bim and E-selectin both in vitro and in vivo Our study suggests that Malat1 plays critical protective roles in ischemic stroke.SIGNIFICANCE STATEMENT Accumulative studies have demonstrated the important regulatory roles of microRNAs in vascular and neural damage after ischemic stroke. However, the functional significance and mechanisms of other classes of noncoding RNAs in cerebrovascular pathophysiology after stroke are less studied. Here we demonstrate a novel role of Malat1, a long noncoding RNA that has been originally identified as a prognostic marker for non-small cell lung cancer, in cerebrovascular pathogenesis of ischemic stroke. Our experiments have provided the first evidence that Malat1 plays anti-apoptotic and anti-inflammatory roles in brain microvasculature to reduce ischemic cerebral vascular and parenchymal damages. Our studies also suggest that lncRNAs can be therapeutically targeted to minimize poststroke brain damage.
| S-EPMC5320610 | biostudies-other
Project description:MALAT1 has previously been described as a metastasis-promoting long noncoding RNA (lncRNA). We show here, however, that targeted inactivation of the Malat1 gene in a transgenic mouse model of breast cancer, without altering the expression of its adjacent genes, promotes lung metastasis, and that this phenotype can be reversed by genetic add-back of Malat1. Similarly, knockout of MALAT1 in human breast cancer cells induces their metastatic ability, which is reversed by re-expression of Malat1. Conversely, overexpression of Malat1 suppresses breast cancer metastasis in transgenic, xenograft, and syngeneic models. Mechanistically, the MALAT1 lncRNA binds and inactivates the prometastatic transcription factor TEAD, preventing TEAD from associating with its co-activator YAP and target gene promoters. Moreover, MALAT1 levels inversely correlate with breast cancer progression and metastatic ability. These findings demonstrate that MALAT1 is a metastasis-suppressing lncRNA rather than a metastasis promoter in breast cancer, calling for rectification of the model for this highly abundant and conserved lncRNA.
| S-EPMC6265076 | biostudies-literature
Project description:MALAT1, one of the few highly conserved nuclear long noncoding RNAs (lncRNAs), is abundantly expressed in normal tissues. Previously, targeted inactivation and genetic rescue experiments identified MALAT1 as a suppressor of breast cancer lung metastasis. On the other hand, Malat1-knockout mice are viable and develop normally. On a quest to discover the fundamental roles of MALAT1 in physiological and pathological processes, we find that this lncRNA is downregulated during osteoclastogenesis in humans and mice. Remarkably, Malat1 deficiency in mice promotes osteoporosis and bone metastasis of melanoma and mammary tumor cells, which can be rescued by genetic add-back of Malat1. Mechanistically, Malat1 binds to Tead3 protein, a macrophage-osteoclast-specific Tead family member, blocking Tead3 from binding and activating Nfatc1, a master regulator of osteoclastogenesis, which results in the inhibition of Nfatc1-mediated gene transcription and osteoclast differentiation. Notably, single-cell transcriptome analysis of clinical bone samples reveals that reduced MALAT1 expression in pre-osteoclasts and osteoclasts is associated with osteoporosis and metastatic bone lesions. Altogether, these findings identify Malat1 as a lncRNA that protects against osteoporosis and bone metastasis.
| S-EPMC10944492 | biostudies-literature
Project description:Human islet isolation is a cost-/resource-intensive program generating islets for cell therapy in Type 1 diabetes. However, only a third of cadaveric pancreas get to clinical transplantation due to low quality/number of islets. There is a need to identify biomarker(s) that predict the quality of islets, prior to initiating their isolation. Here, we sequenced transcriptome from 18 human islet preparations stratified into three groups (Gr.1: Best quality/transplantable islets, Gr.2: Intermediary quality, Gr.3: Inferior quality/non-transplantable islets) based on routine measurements including islet purity/viability. Machine-learning algorithms involving penalized regression analyses identified 10 long-non-coding(lnc)RNAs significantly different across all group-wise comparisons (Gr1VsGr2, Gr2vsGr3, Gr1vsGr3). Two variants of Metastasis-Associated Lung Adenocarcinoma Transcript-1(MALAT1) lncRNA were common across all comparisons. We confirmed RNA-seq findings in a "validation set" of 75 human islet preparations. Finally, in 19 pancreas samples, we demonstrate that assessing the levels of MALAT1 variants alone (ROC curve AUC: 0.83) offers highest specificity in predicting post-isolation islet quality and improves the predictive potential for clinical islet transplantation when combined with Edmonton Donor Points/Body Mass Index(BMI)/North American Islet Donor Score(NAIDS). We present this resource of islet-quality-stratified lncRNA transcriptome data and identify MALAT1 as a biomarker that significantly enhances current selection methods for clinical (GMP)-grade islet isolation.
| S-EPMC6777802 | biostudies-literature
Project description:RNA targeting has gained traction over the past decade. It has become clear that dysregulation of RNA can be linked to many diseases, leading to a need for new scaffolds recognizing RNA specifically. Long noncoding RNAs are emerging as key controllers of gene expression and potential therapeutic targets. However, traditional targeting methods have overwhelmingly been focused on proteins. In this study, we used a protein computational tool and found several possible targetable pockets in a structurally characterized long noncoding RNA, MALAT1. Screening against those identified pockets revealed several hit compounds. We tested the binding of those compounds to MALAT1 RNA and tRNA as a negative control, using SPR. While several compounds were nonspecific binders, others were able to recognize MALAT1 specifically. One of them, MTC07, has an apparent affinity of 400.2 ± 14.4 μM. Although it has weak affinity, MTC07 is the first compound targeting MALAT1 originating from in silico docking.
| S-EPMC8201487 | biostudies-literature
Project description:BackgroundMetastasis-associated lung adenocarcinoma transcript 1 (MALAT1) participates in the occurrence and development of cardiovascular and cerebrovascular diseases such as stroke and coronary heart disease by regulating inflammatory reactions, programmed cell death, and other pathological processes. Previous studies revealed that the MALAT1 gene polymorphism was associated with cardiac and cerebrovascular diseases. However, the prognostic role of the MALAT1 polymorphism in major adverse cardiac and cerebrovascular events (MACCEs) remains unknown. Therefore, this study intends to explore the association between the MALAT1 rs3200401 polymorphism and MACCEs.MethodWe enrolled 617 myocardial infarction (MI) patients and 1125 control participants who attended the First Affiliated Hospital of Xinjiang Medical University from January 2010 to 2018. SNPscan™ typing assays were used to detect the MALAT1 rs3200401 genotype. During the follow-up, MACCEs were recorded. Kaplan-Meier curves and univariate and multivariate Cox survival analyses were used to explore the correlation between MALAT1 gene polymorphisms and the occurrence of MACCEs.ResultsAmong the total participants and MI patients, the frequencies of the T allele (total Participants 19.5% vs. 15.3%, P = 0.047, MI patients 20.7% vs. 14.1%, P = 0.014) and CT + TT genotypes (total Participants 37.4% vs. 28.1%, P = 0.013, MI patients 39.5% vs. 25.8%, P = 0.003) were significantly higher in subjects with MACCEs than in subjects without MACCEs. However, in control participants, the frequencies of the T allele (16.6% vs. 16.0%, P = 0.860) and CT + TT genotypes (31.4% vs. 29.3%, P = 0.760) were not higher in subjects with MACCEs than in subjects without MACCEs. In addition, among the total participants and MI patients, the Kaplan-Meier curve analysis indicated that the subjects with rs3200401 CT + TT genotypes had a higher incidence of MACCEs than CC genotype carriers (P = 0.015, P = 0.001). Nevertheless, similar results were not observed in the control participants (P = 0.790). Multivariate Cox regression indicated that compared with patients with the CC genotype, patients with CT + TT genotypes had a 1.554-fold increase in MACCE risk (hazard ratio: 1.554, 95% confidence interval: 1.060-2.277, P = 0.024).ConclusionsThe MALAT1 rs3200401 CT + TT genotypes could be a risk factor for MACCEs in MI patients, suggesting that the MALAT1 gene may become a biomarker for poor prognosis in MI patients.
| S-EPMC8991554 | biostudies-literature
Project description:The metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) regulates cell motility via the transcriptional or post-transcriptional control of motility-related genes. Whether MALAT1 plays a critical role in cancer progression in breast cancer remains unclear. In this study, we found that MALAT1 was downregulated in breast tumor cell lines and cancer tissue, and showed that knockdown of MALAT1 in breast cancer cell lines induced an epithelial-to-mesenchymal transition (EMT) program via phosphatidylinositide-3 kinase-AKT pathways. Furthermore, lower expression of MALAT1 in breast cancer patients was associated with shorter relapse-free survival. Thus, our results indicate for the first time that MALAT1 is a novel regulator of EMT in breast cancer and may be a potential therapeutic target for breast cancer metastasis.
| S-EPMC4503053 | biostudies-literature
Project description:BackgroundMetastasis-associated lung adenocarcinoma transcript 1 (MALAT1) drives tumorigenesis of various human cancers. However, the association between MALAT1 variants and gastric cancer (GC) risk is unknown. We performed a case-control study to evaluate the possible association between rs619586 and rs3200401 SNPs in MALAT and GC risk.MethodsSamples from 458 patients with GC and 381 controls were genotyped using the TaqMan genotyping assay.ResultsIn stratified analyses, we observed that rs3200401 CT in the codominant model and CT+TT in the dominant model were associated with increased GC risk in male patients (CT: odds ratio [OR] = 1.81, 95% confidence interval [CI] = 1.09-3.01, p = 0.022; CT+TT: OR = 1.74, 95% CI = 1.07-2.83, p = 0.026), and the differentiated (CT: OR =1.79, 95% CI = 1.18-2.73, p = 0.007; CT+TT: OR = 1.76, 95% CI = 1.17-2.64, p = 0.007), and intestinal (CT: OR = 1.67, 95% CI = 1.11-2.49, p = 0.013; CT+TT: OR = 1.68, 95% CI = 1.14-2.47, p = 0.009) GC subgroups.ConclusionMALAT1 rs3200401 increases GC susceptibility and might affect GC development. Further studies are needed to validate our results in large populations and different ethnic groups.
| S-EPMC7767557 | biostudies-literature
Project description:Macrophage activation, i.e., classical M1 and the alternative M2, plays a critical role in many pathophysiological processes, such as inflammation and tissue injury and repair. Although the regulation of macrophage activation has been under extensive investigation, there is little knowledge about the role of long noncoding RNAs (lncRNAs) in this event. In this study, we found that lncRNA Malat1 expression is distinctly regulated in differentially activated macrophages in that it is upregulated in LPS-treated and downregulated in IL-4-treated cells. Malat1 knockdown attenuates LPS-induced M1 macrophage activation. In contrast, Malat1 knockdown enhanced IL-4-activated M2 differentiation as well as a macrophage profibrotic phenotype. Mechanistically, Malat1 knockdown led to decreased expression of Clec16a, silencing of which phenocopied the regulatory effect of Malat1 on M1 activation. Interestingly, Malat1 knockdown promoted IL-4 induction of mitochondrial pyruvate carriers (MPCs) and their mediation of glucose-derived oxidative phosphorylation (OxPhos), which was crucial to the Malat1 regulation of M2 differentiation and profibrotic phenotype. Furthermore, mice with either global or conditional myeloid knockout of Malat1 demonstrated diminished LPS-induced systemic and pulmonary inflammation and injury. In contrast, these mice developed more severe bleomycin-induced lung fibrosis, accompanied by alveolar macrophages displaying augmented M2 and profibrotic phenotypes. In summary, we have identified what we believe is a previously unrecognized role of Malat1 in the regulation of macrophage polarization. Our data demonstrate that Malat1 is involved in pulmonary pathogeneses in association with aberrant macrophage activation.
| S-EPMC6478413 | biostudies-literature