Foxo1-induced miR-92b down-regulation promotes blood-brain barrier damage after ischaemic stroke by targeting NOX4.
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ABSTRACT:
SUBMITTER: Shen J
PROVIDER: S-EPMC8178288 | biostudies-literature |
REPOSITORIES: biostudies-literature
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Project description:Microglia, the major endogenous immune cells of the central nervous system, mediate critical degenerative and regenerative responses in ischaemic stroke. Microglia become "activated", proliferating, and undergoing changes in morphology, gene and protein expression over days and weeks post-ischaemia, with deleterious and beneficial effects. Pro-inflammatory microglia (commonly referred to as M1) exacerbate secondary neuronal injury through the release of reactive oxygen species, cytokines and proteases. In contrast, microglia may facilitate neuronal recovery via tissue and vascular remodelling, through the secretion of anti-inflammatory cytokines and growth factors (a profile often termed M2). This M1/M2 nomenclature does not fully account for the microglial heterogeneity in the ischaemic brain, with some simultaneous expression of both M1 and M2 markers at the single-cell level. Understanding and regulating microglial activation status, reducing detrimental and promoting repair behaviours, present the potential for therapeutic intervention, and open a longer window of opportunity than offered by acute neuroprotective strategies. Pharmacological modulation of microglial activation status to promote anti-inflammatory gene expression can increase neurogenesis and improve functional recovery post-stroke, based on promising preclinical data. Cell-based therapies, using preconditioned microglia, are of interest as a method of therapeutic modulation of the post-ischaemic inflammatory response. Currently, there are no clinically-approved pharmacological options targeting post-ischaemic inflammation. A major developmental challenge for clinical translation will be the selective suppression of the deleterious effects of microglial activity after stroke whilst retaining (or enhancing) the neurovascular repair and remodelling responses of microglia.
| S-EPMC7139954 | biostudies-literature
Project description:ObjectivesCircular RNA (circRNA) is a novel class of RNA, which exhibits powerful biological function in regulating cellular fate of various tumors. Previously, we had demonstrated that over-expression of circRNA circCDYL promoted progression of HER2-negative (HER2-) breast cancer via miR-1275-ULK1/ATG7-autophagic axis. However, the role of circCDYL in HER2-positive (HER2+) breast cancer, in particular its role in modulating cell proliferation, one of the most important characteristics of cellular fate, is unclear.Materials and methodsqRT-PCR and in situ hybridization analyses were performed to examine the expression of circCDYL and miR-92b-3p in breast cancer tissues or cell lines. The biological function of circCDYL and miR-92b-3p were assessed by plate colony formation and cell viability assays and orthotopic animal models. In mechanistic study, circRNAs pull-down, RNA immunoprecipitation, dual luciferase report, western blot, immunohistochemical and immunofluorescence staining assays were performed.ResultsCircCDYL was high-expressed in HER2+ breast cancer tissue, similar with that in HER2- breast cancer tissue. Silencing HER2 gene had no effect on expression of circCDYL in HER2+ breast cancer cells. Over-expression of circCDYL promoted proliferation of HER2+ breast cancer cells but not through miR-1275-ULK1/ATG7-autophagic axis. CircRNA pull down and miRNA deep-sequencing demonstrated the binding of miR-92b-3p and circCDYL. Interestingly, circCDYL did not act as miR-92b-3p sponge, but was degraded in miR-92b-3p-dependent silencing manner. Clinically, expression of circCDYL and miR-92b-3p was associated with clinical outcome of HER2+ breast cancer patients.ConclusionMiR-92b-3p-dependent cleavage of circCDYL was an essential mechanism in regulating cell proliferation of HER2+ breast cancer cells. CircCDYL was proved to be a potential therapeutic target for HER2+ breast cancer, and both circCDYL and miR-92b-3p might be potential biomarkers in predicting clinical outcome of HER2+ breast cancer patients.
| S-EPMC8358302 | biostudies-literature
Project description:MicroRNAs (miRs) are a small non-coding RNA family with a length of 18-22 nucleotides. They are able to regulate gene expression by either triggering target messenger RNA degradation or by inhibiting mRNA translation. Enhancer of zeste homolog 2 (EZH2) is the core enzymatic subunit of polycomb repressor complex 2 and is responsible for the trimethylation of histone 3 on lysine 27 (H3K27me3); it is also able to silence a bundle of tumor suppressor genes through promoter binding. However, little is known regarding the effect of miR?92b on cell autophagy, viability and invasion as well as how it interacts with EZH2. The present study investigated the major role of miR?92b in the autophagy, viability and invasion of breast cancer. It was revealed that in MCF?7 and MDA?MB?453 cells, the expression of miR?92b promoted autophagy induced by starvation and rapamycin treatment. The results of in vitro experiments results demonstrated that miR?92b inhibited breast cancer cell viability, invasion and migration. To further elucidate the regulatory mechanisms of miR?92b in autophagy, a dual luciferase reporter assay was performed to determine whether miR?92b targeted the EZH2 gene. The expression of miR?92b was negatively correlated to EZH2 mRNA expression in breast cancer. Depletion of EZH2 induced phenocopied effects on miR?92b overexpression, thereby demonstrating its importance in autophagy. These results indicated that miR?92b may serve an important role in breast cancer in controlling autophagy, viability and invasion. The present study indicated that miR?92b and EZH2 may serve as potential biomarkers for cancer detection and highlighted their possible therapeutic implications.
| S-EPMC6086627 | biostudies-literature
Project description:Background:Osteosarcoma (OS) is one of the most common types of primary bone tumors which poses negative effects on the bones of both young children and adolescents. LncRNA LINC00472 has been reported to be involved with poor prognostics in breast cancer and ovarian cancer. As a new lncRNA, its role in OS remains to be elusive. Herein, we are focused to explore its regulatory mechanism in the development of OS. Methods:qRT-PCR was utilized to examine the expressions of LINC00472 and miR-300 in OS tissues and cell lines. OS cell lines of U2OS and MG63 were used to investigate the biological function of LINC00472. Xenograft tumor model was built in nude mice with MG63 cells. Results:The expressions of LINC00472 were inhibited in OS tissues and cells, and were negatively related to the expressions of miR-300. LINC00472 directly targeted miR-300. FOXO1 was inhibited in OS tissues and its expressions were negatively related to the expressions of miR-300. LINC00472 over-expressions decreased cell proliferation abilities and colony formation abilities. These effects were mediated by miR-300. The silence of LINC00472 and over-expressions of miR-300 suppressed FOXO1 expressions. LINC00472 greatly reduced tumor growth in vivo and this effect was attenuated by miR-300 mimic. Conclusions:From all the experiments and observations, we demonstrated that LINC00472 could be a potential tumor suppressor in OS through interacting with miR-300 and FOXO1.
| S-EPMC7106848 | biostudies-literature
Project description:Despite great efforts in stroke research, disability and recurrence rates in ischaemic stroke remain unacceptably high. To address this issue, one potential target for novel therapeutics is the glycoprotein von Willebrand factor (vWF), which increases in thrombogenicity especially under high shear rates as it bridges between vascular sub-endothelial collagen and platelets. The rationale for vWF as a potential target in stroke comes from four bodies of evidence. (1) Animal models which recapitulate the pathogenesis of stroke and validate the concept of targeting vWF for stroke prevention and the use of the vWF cleavage enzyme ADAMTS13 in acute stroke treatment. (2) Extensive epidemiologic data establishing the prognostic role of vWF in the clinical setting showing that high vWF levels are associated with an increased risk of first stroke, stroke recurrence or stroke-associated mortality. As such, vWF levels may be a suitable marker for further risk stratification to potentially fine-tune current risk prediction models which are mainly based on clinical and imaging data. (3) Genetic studies showing an association between vWF levels and stroke risk on genomic levels. Finally, (4) studies of patients with primary disorders of excess or deficiency of function in the vWF axis (e.g. thrombotic thrombocytopenic purpura and von Willebrand disease, respectively) which demonstrate the crucial role of vWF in atherothrombosis. Therapeutic inhibition of VWF by novel agents appears particularly promising for secondary prevention of stroke recurrence in specific sub-groups of patients such as those suffering from large artery atherosclerosis, as designated according to the TOAST classification.
| S-EPMC6193403 | biostudies-literature
Project description:Background and purposeThe chemokine receptor CCR5 is well known for its function in immune cells; however, it is also expressed in the brain, where its specific role remains to be elucidated. Because genetic factors may influence the risk of developing cerebral ischaemia or affect its clinical outcome, we have analysed the role of CCR5 in experimental stroke.Experimental approachPermanent cerebral ischaemia was performed by occlusion of the middle cerebral artery in wild-type and CCR5-deficient mice. Locomotor behaviour, infarct size and histochemical alterations were analysed at different time points after occlusion.Key resultsThe cerebral vasculature was comparable in wild-type and CCR5-deficient mice. However, the size of the infarct and the motor deficits after occlusion were markedly increased in CCR5-deficient mice as compared with wild type. No differences between wild-type and CCR5-deficient mice were elicited by occlusion with respect to the morphology and abundance of astrocytes and microglia. Seven days after occlusion the majority of CCR5-deficient mice displayed neutrophil invasion in the infarct region, which was not observed in wild type. As compared with wild type, the infarct regions of CCR5-deficient mice were characterized by increased neuronal death.Conclusions and implicationsLack of CCR5 increased the severity of brain injury following occlusion of the middle cerebral artery. This is of particular interest with respect to the relatively frequent occurrence of CCR5 deficiency in the human population (1-2% of the Caucasian population) and the advent of CCR5 inhibitors as novel drugs.
| S-EPMC2874853 | biostudies-literature
Project description:Genome-wide association study identifies a variant in HDAC9 associated with large vessel ischemic stroke
| EGAS00000000103 | EGA
Project description:Decidualization of the endometrial stromal cells (ESCs) is essential for successful embryo implantation. It involves the transformation of fibroblastic cells into epithelial-like cells that secrete cytokines, growth factors, and proteins necessary for implantation. Previous studies have revealed altered expression of miR-375 in the endometrium of patients with recurrent implantation failure and the ectopic stromal cells of patients with endometriosis. However, the exact molecular mechanisms, particularly the role of microRNAs (miRNAs) in the regulation of decidualization, remain elusive. In this study, we investigated whether decidualization is affected by miR-375 and its potential target(s). The findings demonstrated the downregulation of the expression of miR-375 in the secretory phase compared to its expression in the proliferative phase of the endometrium in normal donors. In contrast, it was upregulated in the secretory phase of the endometrium in infertility patients. Furthermore, during decidualization of ESCs in vitro, overexpression of miR-375 significantly reduced the transcript-level expression of forkhead box protein O1 (FOXO1), prolactin (PRL), and insulin-like growth factor binding protein-1 (IGFBP1), the well-known decidual cell markers. Overexpression of miR-375 also resulted in reduced decidualization-derived intracellular and mitochondrial reactive oxygen species (ROS) levels. Using the luciferase assay, we confirmed that NADPH oxidase 4 (NOX4) is a direct target of miR-375. Collectively, the study showed that the miR-375-mediated NOX4 downregulation reduced ROS production and attenuated the decidualization of ESCs. It provides evidence that miR-375 is a negative regulator of decidualization and could serve as a potential target for combating infertility.
| S-EPMC9646565 | biostudies-literature
Project description:Ischaemic stroke is a common condition leading to human disability and death. Previous studies have shown that oleanolic acid (OA) ameliorates oxidative injury and cerebral ischaemic damage, and miR-186-5p is verified to be elevated in serum from ischaemic stroke patients. Herein, we investigated whether OA regulates miR-186-5p expression to control neuroglobin (Ngb) levels, thereby inhibiting neuronal pyroptosis in ischaemic stroke. Three concentrations of OA (0.5, 2, or 8 μM) were added to primary hippocampal neurons subjected to oxygen-glucose deprivation/reperfusion (OGD/R), a cell model of ischaemic stroke. We found that OA treatment markedly inhibited pyroptosis. qRT-PCR and western blot revealed that OA suppressed the expression of pyroptosis-associated genes. Furthermore, OA inhibited LDH and proinflammatory cytokine release. In addition, miR-186-5p was downregulated while Ngb was upregulated in OA-treated OGD/R neurons. MiR-186-5p knockdown repressed OGD/R-induced pyroptosis and suppressed LDH and inflammatory cytokine release. In addition, a dual luciferase reporter assay confirmed that miR-186-5p directly targeted Ngb. OA reduced miR-186-5p to regulate Ngb levels, thereby inhibiting pyroptosis in both OGD/R-treated neurons and MCAO mice. In conclusion, OA alleviates pyroptosis in vivo and in vitro by downregulating miR-186-5p and upregulating Ngb expression, which provides a novel theoretical basis illustrating that OA can be considered a drug for ischaemic stroke.
| S-EPMC8752321 | biostudies-literature
Project description:Blood-brain barrier (BBB) integrity injury within the thrombolytic time window is becoming a critical target to reduce haemorrhage transformation (HT). We have previously reported that BBB damage was initially damaged in non-infarcted striatum after acute ischaemia stroke. However, the underlying mechanism is not clear. Since acute ischaemic stroke could induce a significant increase of dopamine release in striatum, in current study, our aim is to investigate the role of dopamine receptor signal pathway in BBB integrity injury after acute ischaemia using rat middle cerebral artery occlusion model. Our data showed that 2-h ischaemia induced a significant increase of endogenous tissue plasminogen activator (tPA) in BBB injury area and intra-striatum infusion of tPA inhibitor neuroserpin, significantly alleviated 2-h ischaemia-induced BBB injury. In addition, intra-striatum infusion of D1 receptor antagonist SCH23390 significantly decreased ischaemia-induced upregulation of endogenous tPA, accompanied by decrease of BBB injury and occludin degradation. More important, inhibition of hypoxia-inducible factor-1 alpha with inhibitor YC-1 significantly decreased 2-h ischaemia-induced endogenous tPA upregulation and BBB injury. Taken together, our data demonstrate that acute ischaemia disrupted BBB through activation of endogenous tPA via HIF-1? upregulation, thus representing a new therapeutic target for protecting BBB after acute ischaemic stroke.
| S-EPMC7417722 | biostudies-literature