Mechanism of MALAT1 preventing apoptosis of vascular endothelial cells induced by oxygen–glucose deficiency and reoxidation

GSK3β Inhibition Is the Molecular Pivot That Underlies the Mir-210-Induced Attenuation of Intrinsic Apoptosis Cascade during Hypoxia

Apoptotic cell death is a deleterious consequence of hypoxia-induced cellular stress. The master hypoxamiR, microRNA-210 (miR-210), is considered the primary driver of the cellular response to hypoxia stress. We have recently demonstrated that miR-210 attenuates hypoxia-induced apoptotic cell death. In this paper, we unveil that the miR-210-induced inhibition of the serine/threonine kinase Glycogen Synthase Kinase 3 beta (GSK3β) in AC-16 cardiomyocytes subjected to hypoxia stress underlies the salutary protective response of miR-210 in mitigating the hypoxia-induced apoptotic cell death. Using transient overexpression vectors to augment miR-210 expression concomitant with the ectopic expression of the constitutive active GSK3β S9A mutant (ca-GSK3β S9A), we exhaustively performed biochemical and molecular assays to determine the status of the hypoxia-induced intrinsic apoptosis cascade. Caspase-3 activity analysis coupled with DNA fragmentation assays cogently demonstrate that the inhibition of GSK3β kinase activity underlies the miR-210-induced attenuation in the hypoxia-driven apoptotic cell death. Further elucidation and delineation of the upstream cellular events unveiled an indispensable role of the inhibition of GSK3β kinase activity in mediating the miR-210-induced mitigation of the hypoxia-driven BAX and BAK insertion into the outer mitochondria membrane (OMM) and the ensuing Cytochrome C release into the cytosol. Our study is the first to unveil that the inhibition of GSK3β kinase activity is indispensable in mediating the miR-210-orchestrated protective cellular response to hypoxia-induced apoptotic cell death.

The Role of the lncRNA MALAT1 in Neuroprotection against Hypoxic/Ischemic Injury

Hypoxic and ischemic brain injury can cause neurological disability and mortality, and has become a serious public health problem worldwide. Long-chain non-coding RNAs are involved in the regulation of many diseases. Metastasis-related lung adenocarcinoma transcript 1 (MALAT1) is a type of long non-coding RNA (lncRNA), known as long intergenic non-coding RNA (lincRNA), and is highly abundant in the nervous system. The enrichment of MALAT1 in the brain indicates that it may be associated with important functions in pathophysiological processes. Accordingly, the role of MALAT1 in neuronal cell hypoxic/ischemic injury has been gradually discovered over recent years. In this article, we summarize recent research regarding the neuroprotective molecular mechanism of MALAT1 and its regulation of pathophysiological processes of brain hypoxic/ischemic injury. MALAT1 may function as a regulator through interaction with proteins or RNAs to perform its role, and may therefore serve as a therapeutic target in cerebral hypoxia/ischemia.

miR-210 Regulates Apoptotic Cell Death during Cellular Hypoxia and Reoxygenation in a Diametrically Opposite Manner

Apoptotic cell death of cardiomyocytes is a characteristic hallmark of ischemia-reperfusion (I/R) injury. The master hypoxamiR, microRNA-210 (miR-210), is considered the primary driver of the cellular response to hypoxic stress. However, to date, no consensus has emerged with regards to the polarity of the miR-210-elicited cellular response, as miR-210 has been shown to exacerbate as well as attenuate hypoxia-driven apoptotic cell death. Herein, in AC-16 cardiomyocytes subjected to hypoxia-reoxygenation (H-R) stress, we unravel novel facets of miR-210 biology and resolve the biological response mediated by miR-210 into the hypoxia and reoxygenation temporal components. Using transient overexpression and decoy/inhibition vectors to modulate miR-210 expression, we elucidated a Janus role miR-210 in the cellular response to H-R stress, wherein miR-210 mitigated the hypoxia-induced apoptotic cell death but exacerbated apoptotic cell death during cellular reoxygenation. We further delineated the underlying cellular mechanisms that confer this diametrically opposite effect of miR-210 on apoptotic cell death. Our exhaustive biochemical assays cogently demonstrate that miR-210 attenuates the hypoxia-driven intrinsic apoptosis pathway, while significantly augmenting the reoxygenation-induced caspase-8-mediated extrinsic apoptosis pathway. Our study is the first to unveil this Janus role of miR-210 and to substantiate the cellular mechanisms that underlie this functional duality.

A molecular insight of inflammatory cascades in rheumatoid arthritis and anti-arthritic potential of phytoconstituents

Rheumatoid arthritis (RA) is an auto-immune inflammatory disorder of the synovial lining of joints marked by immune cells infiltration and hyperplasia of synovial fibroblasts which results in articular cartilage destruction and bone erosion. The current review will provide comprehensive information and results obtained from the recent research on the phytochemicals which were found to have potential anti-arthritic activity along with the molecular pathway that were targeted to control RA progression. In this review, we have summarized the scientific data from various animal studies about molecular mechanisms, possible side effects, associations with conventional therapies, and the role of complementary and alternative medicines (CAM) for RA such as ayurvedic medicines in arthritis. In the case of RA, phytochemicals have been shown to act through different pathways such as regulation of inflammatory signaling pathways, T cell differentiation, inhibition of angiogenic factors, induction of the apoptosis of fibroblast-like synoviocytes (FLS), inhibition of autophagic pathway by inhibiting High-mobility group box 1 protein (HMGB-1), Akt/ mTOR pathway and HIF-1α mediated Vascular endothelial growth (VEGF) expression. Also, osteoclasts differentiation is inhibited by down-regulating the VEGF expression by decreasing the accumulation of the ARNT (Aryl Hydrocarbon Receptor Nuclear Translocator)-HIF-1α complex Although phytochemicals have shown to exert potential anti-arthritic activity in many animal models and further clinical data is needed to confirm their safety, efficacy, and interactions in humans.

Emerging role of long non-coding RNAs in endothelial dysfunction and their molecular mechanisms

Long non-coding RNAs (lncRNAs) are the novel class of transcripts involved in transcriptional, post-transcriptional, translational, and post-translational regulation of physiology and the pathology of diseases. Studies have evidenced that the impairment of endothelium is a critical event in the pathogenesis of atherosclerosis and its complications. Endothelial dysfunction is characterized by an imbalance in vasodilation and vasoconstriction, oxidative stress, proinflammatory factors, and nitric oxide bioavailability. Disruption of the endothelial barrier permeability, the first step in developing atherosclerotic lesions is a consequence of endothelial dysfunction. Though several factors interfere with the normal functioning of the endothelium, intrinsic epigenetic mechanisms governing endothelial function are regulated by lncRNAs and perturbations contribute to the pathogenesis of the disease. This review comprehensively addresses the biogenesis of lncRNA and molecular mechanisms underlying and regulation in endothelial function. An insight correlating lncRNAs and endothelial dysfunction-associated diseases can positively impact the development of novel biomarkers and therapeutic targets in endothelial dysfunction-associated diseases and treatment strategies.

Characterization of LncRNA expression profile and identification of functional LncRNAs associated with unstable angina

Background

Increasing evidences suggest that long noncoding RNAs (lncRNAs) play critical roles in the pathogenesis of coronary artery disease (CAD). However, the association between lncRNAs expression profiles and unstable angina (UA) remained poorly known. Thus, the present study aims to investigate expression patterns, biological functions, and diagnostic value of lncRNAs in UA.

Methods

The present study explored the lncRNA and mRNA expression profiles in peripheral blood mononuclear cells (PBMCs) of UA patients and normal coronary artery (NCA) controls using RNA‐seq. The biological function of differentially expressed lncRNAs was analyzed using gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis. The expression of the selected lncRNAs was validated in another 44 UA patients and 46 NCA controls. Receiver operating characteristic curve (ROC) was performed to evaluate the diagnostic value of lncRNAs for UA.

Results

A total of 98 lncRNAs and 615 mRNAs were observed differentially expressed in PBMCs of UA patients as compared to NCA controls. The 10 most upregulated lncRNAs were LNC_000226, DANCR, RP1‐167A14.2, LNC_002091, LNC_001526, LNC_001165, LNC_002772, LNC_000088, LNC_001226, and FAM157C, and the 10 most downregulated lncRNAs were RP11‐734I18.1, RP11‐185E8.1, RP11‐360I2.1, LNC_001302, LNC_001287, RN7SL471P, LNC_000914, LINC01506, RP11‐160E2.6, and LNC_000995. LNC_000226 and MALAT1 have high area under the curve values (AUC) for distinguishing UA from NCA patients (0.810 and 0.799, respectively), and the combination of MALAT1 and LNC_000226 increased the AUC value to 0.878.

Conclusions

The present study added our understanding about the lncRNA expression profile in UA patients and provided potential biomarkers for the diagnosis of UA.

LncRNA MALAT1 inhibits hypoxia/reoxygenation-induced human umbilical vein endothelial cell injury via targeting the microRNA-320a/RAC1 axis

Angiogenesis is believed to protect against hypoxia/reoxygenation (H/R)-induced cell injury. MALAT1 and microRNA-320a (miR-320a) are involved in cancer angiogenesis. To investigate the function of the MALAT1/miR-320a axis in H/R-induced cell injury, human umbilical vein endothelial cell (HUVEC) angiogenesis was detected using the Cell Counting Kit-8 (CCK-8), Transwell migration, cell adhesion and tube formation assays. The expression of MALAT1 and miR-320a was revealed by quantitative reverse transcription polymerase chain reaction (qRT-PCR). The direct binding relationship between miR-320a and MALAT1 was detected by RNA immunoprecipitation (RIP) and dual luciferase reporter assays. The data indicated that H/R induces angiogenesis injury and that the expression of MALAT1 was augmented in H/R-stimulated HUVECs. Overexpression of MALAT1 alleviated H/R-stimulated HUVEC dysfunction, whereas silencing of MALAT1 exerted the opposite effects. MALAT1 also reduced miR-320a levels in HUVECs. Overexpression of miR-320a repressed the function of MALAT1 on H/R-stimulated HUVECs, whereas inhibition of miR-320a exerted the opposite effect. Additionally, miR-320a inhibition alleviated H/R-stimulated HUVEC injury via RAC1. Taken together, this investigation concluded that MALAT1 represses H/R-stimulated HUVEC injury by targeting the miR-320a/RAC1 axis.

The lncRNA Malat1 regulates microvascular function after myocardial infarction in mice via miR-26b-5p/Mfn1 axis-mediated mitochondrial dynamics

RATIONALE

Myocardial infarction (MI) is a leading cause of cardiovascular mortality globally. The improvement of microvascular function is critical for cardiac repair after MI. Evidence now points to long non-coding RNAs (lncRNAs) as key regulators of cardiac remodelling processes. The lncRNA Malat1 is involved in the development and progression of multiple cardiac diseases. Studies have shown that Malat1 is closely related to the regulation of endothelial cell regeneration. However, the potential molecular mechanisms of Malat1 in repairing cardiac microvascular dysfunction after MI remain unreported.

METHODS AND RESULTS

The present study found that Malat1 is upregulated in the border zone of infarction in mouse hearts, as well as in isolated cardiac microvascular endothelial cells (CMECs). Targeted knockdown of Malat1 in endothelial cells exacerbated oxidative stress, attenuated angiogenesis and microvascular perfusion, and as a result decreased cardiac function in MI mice. Further studies showed that silencing Malat1 obviously inhibited CMEC proliferation, migration and tube formation, which was at least in part attributed to disturbed mitochondrial dynamics and activation of the mitochondrial apoptosis pathway. Moreover, bioinformatic analyses, luciferase assays and pull-down assays indicated that Malat1 acted as a competing endogenous RNA (ceRNA) for miR-26b-5p and formed a signalling axis with Mfn1 to regulate mitochondrial dynamics and endothelial functions. Overexpression of Mfn1 markedly reversed the microvascular dysfunction and CMEC injuries that were aggravated by silencing Malat1 via inhibition of excessive mitochondrial fragments and mitochondria-dependent apoptosis.

CONCLUSIONS

The present study elucidated the functions and mechanisms of Malat1 in cardiac microcirculation repair after MI. The underlying mechanisms of the effects of Malat1 could be attributed to its blocking effects on miR-26b-5p/Mfn1 pathway-mediated mitochondrial dynamics and apoptosis.

The lncRNA MALAT1 participates in regulating coronary slow flow endothelial dysfunction through the miR-181b-5p-MEF2A-ET-1 axis

BACKGROUND

Coronary slow flow (CSF) refers to coronary arteries with no obvious stenosis but have slow coronary flow without effective treatment. The main cause of CSF is endothelial dysfunction. The long non-coding RNA (lncRNA) MALAT1 is involved in regulating endothelial dysfunction, but its role in CSF endothelial dysfunction is still unclear.

METHODS

We included 41 CSF patients and 37 controls in the study, who all underwent coronary angiography, echocardiography, and brachial artery flow-mediated dilatation (FMD) examination. Human umbilical vein endothelial cells (HUVECs) stimulated by oxygen-glucose deprivation were used as CSF-induced HUVECs. Plasma endothelin-1 (ET-1) concentrations were determined by enzyme-linked immunosorbent assay (ELISA). The expression levels of MALAT1, miR-181b-5p, myocyte enhancer factor 2A (MEF2A), and ET-1 were measured by qRT-PCR or western blotting. Cell proliferation was determined by 5-ethynyl-2'-deoxyuridine (EdU) and Cell Counting Kit-8 (CCK-8) assays. Apoptosis was examined by flow cytometry. The relationship between miR-181b-5p and MALAT1 or MEF2A was verified by dual-luciferase reporter assay. MEF2A binding directly to the ET-1 promoter region was verified via chromatin immunoprecipitation (ChIP) assay.

RESULTS

MALAT1 and ET-1 were increased, and miR-181b-5p was decreased in the peripheral blood of the CSF patients, and could be used as predictors of CSF. In the CSF-induced HUVECs, MALAT1 was highly expressed, and MALAT1 knockdown improved endothelial function. In contrast, miR-181b-5p was downregulated in the CSF-induced HUVECs, and miR-181b-5p overexpression improved endothelial function. While MEF2A was highly enriched in CSF-induced HUVECs, MEF2A knockdown reduced ET-1 and increased the endothelial function of CSF-induced HUVECs as a transcriptional regulator of ET-1. MALAT1 modulated MEF2A expression positively by sponging miR-181b-5p.

CONCLUSIONS

Endothelial function is reduced in CSF. MALAT1 participates in regulating CSF endothelial dysfunction through the miR-181b-5p-MEF2A-ET-1 axis, and could provide a new target for CSF treatment.

The Regulatory Functions of lncRNAs on Angiogenesis Following Ischemic Stroke

Ischemic stroke is one of the leading causes of global mortality and disability. It is a multi-factorial disease involving multiple factors, and gene dysregulation is considered as the major molecular mechanisms underlying disease progression. Angiogenesis can promote collateral circulation, which helps the restoration of blood supply in the ischemic area and reduces ischemic necrosis following ischemic injury. Aberrant expression of long non-coding RNAs (lncRNAs) in ischemic stroke is associated with various biological functions of endothelial cells and serves essential roles on the angiogenesis of ischemic stroke. The key roles of lncRNAs on angiogenesis suggest their potential as novel therapeutic targets for future diagnosis and treatment. This review elucidates the detailed regulatory functions of lncRNAs on angiogenesis following ischemic stroke through numerous mechanisms, such as interaction with target microRNAs, downstream signaling pathways and target molecules.

Targeting MALAT1 and miRNA-181a-5p for the intervention of acute lung injury/acute respiratory distress syndrome

BACKGROUND

ALI/ARDS is a severe lung injury leading to refractory respiratory failure, accounting for high morbidity and mortality. However, therapeutic approaches are rather limited. Targeting long non-coding RNA MALAT1 and microRNA miR-181a-5p might be potential option for ALI/ARDS intervention.

OBJECTIVE

We aimed to investigate the role of MALAT and miR-181a-5p in the pathogenesis of ALI/ARDS, and test the therapeutic effects of targeting MALAT and miR-181a-5p for ALI/ARDS intervention in vitro.

METHODS

MALAT1 and miR-181a-5p levels were measured in plasma from ALI/ARDS patients. In vitro human pulmonary microvascular endothelial cell (HPMEC) injury was induced by LPS treatment, and molecular targets of MALAT1 and miR-181a-5p were explored by molecular biology approaches, mainly focusing on cell apoptosis and vascular inflammation. Interaction between MALAT1 and miR-181a-5p was also detected. Finally, the effects of targeting MALAT1 and miR-181a-5p for ALI/ARDS intervention were validated in a rat ALI/ARDS model.

RESULTS

MALAT1 upregulation and miR-181a-5p downregulation were observed in ALI/ARDS patients. Transfection of mimic miR-181a-5p into HPMECs revealed decreased Fas and apoptosis, along with reduced inflammatory factors. Fas was proved to be a direct target of miR-181a-5p. Similar effects were also present upon MALAT1 knockdown. As for the interaction between MALAT1 and miR-181a-5p, MALAT1 knockdown increased miR-181a-5p expression. Knocking down of MALAT1 and miR-181a-5p could both improve the outcome in ALI/ARDS rats.

CONCLUSION

MALAT1 antagonism or miR-181a-5p could both be potential therapeutic strategies for ALI/ARDS. Mechanistically, miR-181a-5p directly inhibits Fas and apoptosis, along with reduced inflammation. MALAT1 negatively regulates miR-181a-5p.

Exercise-mediated downregulation of MALAT1 expression and implications in primary and secondary cancer prevention

Long non-coding RNAs (lncRNAs) play critical roles in various biological functions and disease processes including cancer. The metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) was initially identified as a lncRNA with elevated expression in primary human non-small cell lung tumors with high propensity to metastasize, and subsequently shown to be highly expressed in numerous other human cancers including breast, ovarian, prostate, cervical, endometrial, gastric, pancreatic, sarcoma, colorectal, bladder, brain, multiple myeloma, and lymphoma. MALAT1 is deeply involved in several physiological processes, including alternative splicing, epigenetic modification of gene expression, cellular senescence, healthy aging, and redox homeostasis. The aim of this work was to investigate the modulation exerted by a single bout of endurance exercise on the level of MALAT1 expression in peripheral blood mononuclear cells (PBMCs) from healthy male donors displaying different training status and redox homeostasis features. Our findings show that MALAT1 is downregulated after acute endurance exercise in subjects whose fitness level guarantee a high expression of SOD1 and SOD2 antioxidant genes and low levels of endogenous oxidative damage. In vitro protocols in Jurkat lymphoblastoid cells exposed to pro-oxidant environment confirmed the link between MALAT1 expression and antioxidant gene modulation, documenting p53 phosphorylation and its recruitment to MALAT1 promoter. Remarkably, analyses of Microarray-Based Gene Expression Profiling revealed high MALAT1 expression in leukemia patients in comparison to healthy control and a significant negative correlation between MALAT1 and SOD1 expression. Collectively our results highlight the beneficial effect of a physically active lifestyle in counteracting aberrant cancer-related gene expression programs by improving the redox buffering capacity.

Targeting MALAT1 and miRNA-181a-5p for the intervention of acute lung injury/acute respiratory distress syndrome

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This article has been retracted at the request of the authors due to a reported lack of agreement among the authors. The usage of the image in E-b part of Figure 7 had not received permission from the co-author. In order to resolve the issue, the authors agreed to retract the article.

Down-regulation of lncRNA MALAT1 alleviates vascular lesion and vascular remodeling of rats with hypertension

Objective: Recently, the effect of long non-coding RNAs (lncRNAs) in hypertension (HTN) has been identified. This study aims to explore the expression of lncRNA metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) in HTN and its role in vascular lesion and remodeling of HTN rats.

Results: LncRNA MALAT1 expression was up-regulated in HTN patients, and lncRNA MALAT1 could be an effective index of HTN diagnosis. Down-regulated MALAT1 and inhibited Notch-1 could reduce relative factor expression, including inflammation-related factors, endothelial function-related factors and oxidative stress-related factors, and inhibit apoptosis of aortic endothelial cells of HTN rats.

Methods: LncRNA MALAT1 expression in HTN patients and healthy controls was detected by reverse transcription quantitative polymerase chain reaction (RT-qPCR). Angiotensin II (Ang II)-induced HTN rat models were injected with MALAT1-siRNA, empty lentivirus vector, Notch pathway inhibitor (DAPT) and dimethyl sulphoxide (DMSO) via caudal vein. After three-week treatment, changes of blood pressure, inflammatory factor levels, endothelial function-related factors, oxidative stress indices and apoptosis of vascular endothelial cells were determined by a series of assays.

Conclusion: This study revealed that down-regulated lncRNA MALAT1 could alleviate the vascular lesion and remodeling of HTN rats, the mechanism may be related to the inhibited activation of Notch signaling pathway.

A genetic variant in the promoter of lncRNA MALAT1 is related to susceptibility of ischemic stroke

Background

Metastasis-associated lung adenocarcinoma transcript-1 (MALAT1) was aberrantly expressed in diverse diseases. Particularly in ischemic stroke (IS), the abnormal expression of MALAT1 played important roles including promotion of angiogenesis, inhibition of apoptosis and inflammation and regulation of autophagy. However, the effects of genetic variation (single nucleotide polymorphisms, SNPs) of MALAT1 on IS have rarely been explored. This study aimed to investigate whether SNPs in promoter of MALAT1 were associated with the susceptibility to IS.

Methods

A total of 316 IS patients and 320 age-, gender-, and ethnicity-matched controls were enrolled in this study. Four polymorphisms in the promoter of MALAT1 (i.e., rs600231, rs1194338, rs4102217, and rs591291) were genotyped by using a custom-by-design 48-Plex SNPscan kit.

Results

The rs1194338 C > A variant in the promoter of MALAT1 was associated with the risk of IS (AC vs. CC: adjusted OR = 0.623, 95% CI, 0.417–0.932, P = 0.021; AA vs. CC: adjusted OR = 0.474, 95% CI, 0.226–0.991, P = 0.047; Dominant model: adjusted OR = 0.596, 95% CI, 0.406–0.874, P = 0.008; A vs. C adjusted OR = 0.658, 95% CI, 0.487–0.890, P = 0.007). The haplotype analysis showed that rs600231-rs1194338-rs4102217-rs591291 (A-C-G-C) had a 1.3-fold increased risk of IS (95% CI, 1.029–1.644, P = 0.027). Logistic regression analysis identified some independent impact factors for IS including rs1194338 AC/AA, TC, TG, HDL-C, LDL-C, Apo-A1, Apo-B and NEFA (P < 0.05).

Conclusions

These results suggest that the rs1194338 AC/AA genotypes may be a protective factor for IS.

The Regulatory Role of Long Noncoding RNAs in Different Brain Cell Types Involved in Ischemic Stroke

Stroke results in high morbidity and high mortality worldwide, with ischemic stroke accounting for 80% to 85%. As effective treatments for ischemic stroke remain limited because of the narrow therapeutic time window, a better understanding of the pathologic mechanism and new therapeutic intervention targets are needed. Due to the development of next-generation sequencing technologies and the genome-wide analysis of eukaryotic transcriptomes, a large amount of evidence to date demonstrates that long noncoding RNAs (lncRNAs) play a vital role in gene regulation and in ischemic stroke. In recent years, many studies have been focused on the clinical significance of lncRNAs in ischemic stroke, and data shows that the pathological processes underlying ischemic stroke are driven by interactions among different brain cell types, including neurons, glial cells, and vascular cells, which actively participate in the mechanisms of tissue injury and repair. In this mini review article, we provide an overview of the characteristics and underlying regulation mechanisms of lncRNAs relevant to different brain cell types during the course of ischemic stroke. Moreover, we reveal the roles of lncRNAs as potential biomarkers and treatment targets in ischemic stroke.

LncRNA MALAT1 modulates ox-LDL induced EndMT through the Wnt/β-catenin signaling pathway

Background

Endothelial-to-mesenchymal transition (EndMT) plays significant roles in atherosclerosis, but the regulatory mechanisms involving lncRNAs remain to be elucidated. Here we sort to identify the role of metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) in ox-LDL-induced EndMT.

Methods

The atherosclerosis model was established by feeding ApoE^−/− mice with high-fat diet, and the levels of lncRNA MALAT1 in mouse arterial tissue were detected by RT-qPCR. Cell model was established by treating human umbilical vein endothelial cells (HUVECs) with ox-LDL, and the levels of EndMT markers, such as CD31, vWF, α-SMA and Vimentin and lncRNA MALAT1 levels were detected and their correlations were analyzed. The role of MALAT1 in EndMT and its dependence on Wnt/β-catenin signaling pathway was further detected by knocking down or overexpressing MALAT1.

Results

MALAT1 was upregulated in high-fat food fed ApoE^−/− mice. HUVECs treated with ox-LDL showed a significant decrease in expression of CD31 and vWF, a significant increase in expression of α-SMA and vimentin, and upregulated MALAT1. An increased MALAT1 level facilitated the nuclear translocation of β-catenin induced by ox-LDL. Inhibition of MALAT1 expression reversed nuclear translocation of β-catenin and EndMT. Moreover, overexpression of MALAT1 enhanced the effects of ox-LDL on HUVEC EndMT and Wnt/β-catenin signaling activation.

Conclusions

Our study revealed that the pathological EndMT required the activation of the MALAT1-dependent Wnt/β-catenin signaling pathway, which may be important for the onset of atherosclerosis.

Trial registration

Not applicable.

Xingnaojing Injection Protects against Cerebral Ischemia Reperfusion Injury via PI3K/Akt-Mediated eNOS Phosphorylation

Xingnaojing (XNJ) injection, derived from traditional Chinese medicine formulation, has a protective effect against stroke, but the underlying mechanism is unclear, which severely limited its clinical application. This research aims to elucidate the role and mechanism of XNJ in reducing cerebral ischemic reperfusion (I/R) injury. Rats received 2 h cerebral ischemia followed by reperfusion of 24 h and were intraperitoneally given 5, 10, or 15 ml/kg XNJ 24 h before ischemia and at the onset of reperfusion, respectively. TTC staining, HE staining, and neurological score were implied to evaluate the effectiveness of XNJ. The protein expressions of PI3K/Akt and eNOS signaling were measured. Experiments were further performed in human brain microvascular endothelial cells (HBMECs) to investigate the protective mechanisms of XNJ. HBMECs were subjected to 3 h oxygen and glucose deprivation following 24 h of reoxygenation (OGD) to mimic cerebral I/R in vitro. PI3K inhibitor LY294002 was added with or without the preconditioning of XNJ. Multiple methods including western blot, immunofluorescence, DAPI staining, JC-1, and flow cytometry were carried out to evaluate the effect of XNJ on HBMECs. XNJ could improve rat cerebral ischemic injury and OGD induced HBMECs apoptosis. In vivo and in vitro researches indicated that the mechanism might be relevant to the activation of PI3K/Akt/eNOS signaling.