LncRNA FTX Regulates Angiogenesis Through miR-342-3p/SPI1 Axis in Stroke

Long noncoding RNA H19 knockdown promotes angiogenesis via IMP2 after ischemic stroke

AIMS

This study aimed to explore the effects of long noncoding RNA (lncRNA) H19 knockdown on angiogenesis and blood-brain barrier (BBB) integrity following cerebral ischemia/reperfusion (I/R) and elucidate their underlying regulatory mechanisms.

METHODS

A middle cerebral artery occlusion/reperfusion model was used to induce cerebral I/R injury. The cerebral infarct volume and neurological impairment were assessed using 2,3,5-triphenyl-tetrazolium chloride staining and neurobehavioral tests, respectively. Relevant proteins were evaluated using western blotting and immunofluorescence staining. Additionally, a bioinformatics website was used to predict the potential target genes of lncRNA H19. Finally, a rescue experiment was conducted to confirm the potential mechanism.

RESULTS

Silencing of H19 significantly decreased the cerebral infarct volume, enhanced the recovery of neurological function, mitigated BBB damage, and stimulated endothelial cell proliferation following ischemic stroke. Insulin-like growth factor 2 mRNA-binding protein 2 (IMP2) is predicted to be a potential target gene for lncRNA H19. H19 knockdown increased IMP2 protein expression and IMP2 inhibition reversed the protective effects of H19 inhibition.

CONCLUSION

Downregulation of H19 enhances angiogenesis and mitigates BBB damage by regulating IMP2, thereby alleviating cerebral I/R injury.

Molecular subtype identification of cerebral ischemic stroke based on ferroptosis-related genes

Cerebral ischemic stroke (CIS) has the characteristics of a high incidence, disability, and mortality rate. Here, we aimed to explore the potential pathogenic mechanisms of ferroptosis-related genes (FRGs) in CIS. Three microarray datasets from the Gene Expression Omnibus (GEO) database were utilized to analyze differentially expressed genes (DEGs) between CIS and normal controls. FRGs were obtained from a literature report and the FerrDb database. Weighted gene co-expression network analysis (WGCNA) and protein-protein interaction (PPI) network were used to screen hub genes. The receiver operating characteristic (ROC) curve was adopted to evaluate the diagnostic value of key genes in CIS, followed by analysis of immune microenvironment, transcription factor (TF) regulatory network, drug prediction, and molecular docking. In total, 128 CIS samples were divided into 2 subgroups after clustering analysis. Compared with cluster A, 1560 DEGs were identified in cluster B. After the construction of the WGCNA and PPI network, 5 hub genes, including MAPK3, WAS, DNAJC5, PRKCD, and GRB2, were identified for CIS. Interestingly, MAPK3 was a FRG that differentially expressed between cluster A and cluster B. The expression levels of 5 hub genes were all specifically highly in cluster A subtype. It is noted that neutrophils were the most positively correlated with all 5 real hub genes. PRKCD was one of the target genes of FASUDIL. In conclusion, five real hub genes were identified as potential diagnostic markers, which can distinguish the two subtypes well.

Non-coding RNAs and angiogenesis in cardiovascular diseases: a comprehensive review

Non-coding RNAs (ncRNAs) have key roles in the etiology of many illnesses, including heart failure, myocardial infarction, stroke, and in physiological processes like angiogenesis. In transcriptional regulatory circuits that control heart growth, signaling, and stress response, as well as remodeling in cardiac disease, ncRNAs have become important players. Studies on ncRNAs and cardiovascular disease have made great progress recently. Here, we go through the functions of non-coding RNAs (ncRNAs) like circular RNAs (circRNAs), and microRNAs (miRNAs) as well as long non-coding RNAs (lncRNAs) in modulating cardiovascular disorders.

Emerging roles of long non-coding RNA FTX in human disorders

Long non-coding RNAs (lncRNAs) are involved the progression of cancerous and non-cancerous disorders via different mechanism. FTX (five prime to xist) is an evolutionarily conserved lncRNA that is located upstream of XIST and regulates its expression. FTX participates in progression of various malignancy including gastric cancer, glioma, ovarian cancer, pancreatic cancer, and retinoblastoma. Also, FTX can be involved in the pathogenesis of non-cancerous disorders such as endometriosis and stroke. FTX acts as competitive endogenous RNA (ceRNA) and via sponging various miRNAs, including miR-186, miR-200a-3p, miR-215-3p, and miR-153-3p to regulate the expression of their downstream target. FTX by targeting various signaling pathways including Wnt/β-catenin, PI3K/Akt, SOX4, PDK1/PKB/GSK-3β, TGF-β1, FOXA2, and PPARγ regulate molecular mechanism involved in various disorders. Dysregulation of FTX is associated with an increased risk of various disorders. Therefore, FTX and its downstream targets may be suitable biomarkers for the diagnosis and treatment of human malignancies. In this review, we summarized the emerging roles of FTX in human cancerous and non-cancerous cells.

The pluripotent factor OCT4A enhances the self-renewal of human dental pulp stem cells by targeting lncRNA FTX in an LPS-induced inflammatory microenvironment

BACKGROUND

Regulating the pluripotency of human dental pulp stem cells (hDPSCs) is key for the self-repair of injured dental pulp. We previously found that OCT4A promotes the proliferation and odontogenic differentiation of human dental pulp cells (hDPCs). Recent studies have shown the interaction between OCT4A and lncRNAs in pluripotency maintenance of various stem cells. The aim of this study was to explore the underlying roles and mechanisms of OCT4A and its related lncRNAs in the proliferation and multidirectional differentiation of hDPSCs in an inflammatory microenvironment.

METHODS

Human lncRNA microarrays were applied to screen out the differentially expressed lncRNAs in hDPSCs between the OCT4A-overexpressing and vector groups. Lipopolysaccharide (LPS) was used to simulate the inflammatory microenvironment. The effects of OCT4A and the lncRNA FTX on the proliferation and multidifferentiation of hDPSCs were observed by the CCK-8 assay, EdU staining, real-time PCR, western blotting, and Alizarin red and oil red O staining. Bioinformatics analysis and chromatin immunoprecipitation (ChIP) assays were performed to clarify the targeted mechanism of OCT4A on FTX. The regulation by FTX of the expression of OCT4A and its downstream pluripotent transcription factors SOX2 and c-MYC was further detected by real-time PCR and western blotting.

RESULTS

The microarray results showed that 978 lncRNAs (250 of which were upregulated and 728 downregulated) were potentially differentially expressed genes (fold change ≥ 2, P < 0.05). LPS stimulation attenuated the self-renewal of hDPSCs. OCT4A enhanced the cell proliferation and multidifferentiation capacities of hDPSCs in an inflammatory microenvironment, while FTX exhibited the opposite effects. OCT4A negatively regulated FTX function by binding to specific regions on the FTX promoter, thereby inhibiting the transcription of FTX. Moreover, overexpression of FTX downregulated the expression of OCT4A, SOX2 and c-MYC, whereas knockdown of FTX facilitated their expression.

CONCLUSIONS

OCT4A was found to be a crucial factor maintaining the self-renewal of hDPSCs by transcriptionally targeting FTX in an inflammatory microenvironment. Moreover, we proposed a novel function of FTX in negatively regulating the pluripotency and multilineage differentiation capacity of hDPSCs. The hierarchical organization between OCT4A and FTX expanded the understanding of the network between transcription factors and lncRNAs in fine-tuning the pluripotency/differentiation balance of adult stem cells, and provided prospective targets for optimizing dental-derived stem cell sources for regenerative endodontics.

Emerging effects of non-coding RNA in vascular endothelial cells during strokes

Vascular and neurological damage are the typical outcomes of ischemic strokes. Vascular endothelial cells (VECs), a substantial component of the blood-brain barrier (BBB), are necessary for normal cerebrovascular physiology. During an ischemic stroke (IS), changes in the brain endothelium can lead to a BBB rupture, inflammation, and vasogenic brain edema, and VECs are essential for neurotrophic effects and angiogenesis. Non-coding RNAs (nc-RNAs) are endogenous molecules, and brain ischemia quickly changes the expression patterns of several non-coding RNA types, such as microRNA (miRNA/miR), long non-coding RNA (lncRNA), and circular RNA (circRNA). Furthermore, vascular endothelium-associated nc-RNAs are important mediators in the maintenance of healthy cerebrovascular function. In order to better understand how VECs are regulated epigenetically during an IS, in this review, we attempted to assemble the molecular functions of nc-RNAs that are linked with VECs during an IS.

LncRNA PEG11as aggravates cerebral ischemia/reperfusion injury after ischemic stroke through miR-342-5p/PFN1 axis

AIM

LncRNAs are highly expressed in the CNS and regulate pathophysiological processes. However, the potential role of lncRNAs inischemic stroke (IS) remains unknown. In this study, we investigated the functions and possible molecular mechanism of lncRNA paternal expressed gene 11 antisense (PEG11as) in this process.

METHODS

Middle cerebral artery occlusion/reperfusion (MCAO/R) mice model and N2a cells model from oxygen-glucose deprivation/reoxygenation (OGD/R) were used to simulate cerebral I/R in vivo and in vitro. High-throughput sequencing (RNA-Seq) was used todetect differential expression of lncRNAs in cerebral I/R. QRT-PCR was used to detect the expression of PEG11as and miR-342-5p. Bioinformatics analysis, FISH, luciferase reporter assay, RIP, Western blot, and immunofluorescence were used to detect the interaction between PEG11as, miR-342-5p and PFN1. The effect on neuronal apoptosis was analyzed using loss-of-function combined with TUNEL, Hoechst, and caspase3 activity assays.

KEY FINDINGS

254 lncRNAs were differentially expressed in MCAO1h/R6h mice. Among them, PEG11as was significantly up-regulated. PEG11as down-regulated could markedly attenuate the brain infarct volume, alleviate neurological deficit in vivo, and effectively promote neuron survival, attenuate neuronal apoptosis both in vivo and in vitro. FISH assay discovered that PEG11as was mainly located in the cytoplasm. Furthermore, we demonstrated that PEG11as was able to bind miR-342-5p to inhibit miR-342-5p activity, whereas the down-regulated of miR-342-5p resulted in profilin 1 (PFN1) overexpression and thus promoting apoptosis.

SIGNIFICANCE

This study suggests that PEG11as regulates neuronal apoptosis by miR-342-5p/PFN1 axis, which may contribute to our understanding of pathogenesis and provide a potential therapeutic option for cerebral I/R.

Long non-coding RNAs as biomarkers and therapeutic targets for ischemic stroke

Background

The problem of ischemic stroke (IS) has become increasingly important in recent years, as it ranks first in the structure of disability and mortality, crowding out other vascular diseases. In this regard, the study of this pathology and the search for new therapeutic and diagnostic tools remains an urgent problem of modern medical science and practice. Long non-coding RNAs (lncRNAs)-based therapeutics and diagnostic tools offer a very attractive area of study. Therefore, this systematic review aims at summarizing current knowledge on promising lncRNAs as biomarkers and therapeutic targets for IS exploring original articles and literature reviews on in vivo, in vitro and ex vivo experiments.

Methods

The current systematic review was performed according to PRISMA guidelines. PubMed, MEDLINE and Google Scholar databases were comprehensively explored to perform the article search.

Results

34 eligible studies were included and analyzed: 25 focused on lncRNAs-based therapeutics and 9 on lncRNAs-based diagnosis. We found 31 different lncRNAs tested as potential therapeutic and diagnostic molecules in cells and animal model experiments. Among all founded lncRNA-based therapeutics and non-invasive diagnostic tools, nuclear enriched abundant transcript 1 (NEAT1) emerged to be the most investigated and proposed as a potential molecule for IS diagnosis and treatment.

Conclusions

Our analysis provides a snapshot of the current scenario regarding the lncRNAs as therapeutic molecules and biomarkers in IS. Different lncRNAs are differently expressed in IS, and some of them can be further evaluated as therapeutic targets and biomarkers for early diagnosis and prognosis or treatment response. However, despite many efforts, none of the selected studies go beyond preclinical studies, and their translation into clinical practice seems to be very premature.

Flow-Responsive Noncoding RNAs in the Vascular System: Basic Mechanisms for the Clinician

The vascular system is largely exposed to the effect of changing flow conditions. Vascular cells can sense flow and its changes. Flow sensing is of pivotal importance for vascular remodeling. In fact, it influences the development and progression of atherosclerosis, controls its location and has a major influx on the development of local complications. Despite its importance, the research community has traditionally paid scarce attention to studying the association between different flow conditions and vascular biology. More recently, a growing body of evidence has been accumulating, revealing that ncRNAs play a key role in the modulation of several biological processes linking flow-sensing to vascular pathophysiology. This review summarizes the most relevant evidence on ncRNAs that are directly or indirectly responsive to flow conditions to the benefit of the clinician, with a focus on the underpinning mechanisms and their potential application as disease biomarkers.