Project description:Over-expression of miR-155 induces changes in the pattern of gene expression of hCMEC/D3 cells. hypothesis tested in the present study was that miR-155 constitute an important regulatory control of the brain endothelial response to inflammatory cytokines. To identify miR-155 target genes in brain endothelim that might be implicated in BBB dysfunction relevant to human disease, we then analysed changes in mRNA expression of hCMEC/D3 cells that overexpress miR-155 and results were contrasted to cells transfected with scrambled miR. To ectopically express miR-155 in hCMEC/D3 cells, 30 nM of pre-miR-155 and the siPORT Amine transfection agent (Applied Biosystems, Warrington, UK) were combined following the manufacturerM-bM-^@M-^Ys instructions.
Project description:Here, we investigated the time-course changes in the pattern of microRNA (miRNA) expression of TNFα and IFNγ-stimulated and unstimulated hCMEC/D3 cells, an immortalized human cerebral microvascular endothelial cell line. In order to investigate pro-inflammatory cytokine-induced changes in miRNA levels in hCMEC/D3 cells, we challenged brain endothelial cells with TNFα and IFNγ (100 ng/ml) for 2 h, 6 h and 24 h and determined microRNA expression in cytokine-stimulated and unstimulated cells
Project description:Over-expression of miR-155 induces changes in the pattern of gene expression of hCMEC/D3 cells. hypothesis tested in the present study was that miR-155 constitute an important regulatory control of the brain endothelial response to inflammatory cytokines.
Project description:Here, we investigated the time-course changes in the pattern of microRNA (miRNA) expression of TNFα and IFNγ-stimulated and unstimulated hCMEC/D3 cells, an immortalized human cerebral microvascular endothelial cell line.
Project description:miR-155 has been shown to participate in host response to infection and neuro-inflammation via negative regulation of blood-brain-barrier (BBB) integrity and T cell function. We hypothesized that miR-155 may contribute to the pathogenesis of cerebral malaria (CM). To test this hypothesis, we used a genetic approach to modulate miR-155 expression in an experimental model of cerebral malaria (ECM). In addition, an engineered endothelialized microvessel system and serum samples from Ugandan children with CM were used to examine an anti-miR-155 as a potential adjunctive therapeutic for severe malaria. Despite higher parasitemia, survival was significantly improved in miR-155-/- mice vs. wild-type littermate mice in ECM. Improved survival was associated with preservation of BBB integrity and reduced endothelial activation, despite increased levels of pro-inflammatory cytokines. Pre-treatment with antagomir-155 reduced vascular leak induced by human CM sera in an ex vivo endothelial microvessel model. These data provide evidence supporting a mechanistic role for miR-155 in host response to malaria via regulation of endothelial activation, microvascular leak and BBB dysfunction in CM.
Project description:The blood-brain barrier (BBB) dysfunction is an initial event of various neuroinflammatory diseases. However, the absence of reliable markers and mechanisms for BBB damage greatly limits the diagnosis and treatment of neuroinflammatory diseases. Soluble CD146 (sCD146) is mainly derived from vascular endothelial cells (ECs) and highly elevated in inflammatory settings. Based on a small cohort, our previous study showed that sCD146 is elevated in the cerebrospinal fluid (CSF) of multiple sclerosis (MS), which is accompanied with BBB damage. Nevertheless, whether sCD146 monitors and regulates the BBB dysfunction remains unknown. Methods: Coupled serum and CSF samples from patients with or without neuroinflammatory diseases were collected via multicenter collaborations. sCD146 was measured by sandwich ELISA using anti-CD146 antibodies AA1 and AA98, both of which were generated in our laboratory. The correlations between sCD146 and other clinical parameters or inflammatory factors were analyzed by Spearman's correlation coefficient analysis. The role of sCD146 on BBB function was examined in an in vitro BBB model. Results: Between July 20, 2011, and February 31, 2017, we collected coupled serum and CSF samples from 823 patients, of which 562 (68.3%) had neuroinflammatory diseases, 44 (5.3%) had remitting MS, and 217 (26.4%) had non-inflammatory neurological diseases (NIND). We found that sCD146 in CSF, but not in serum, is abnormally elevated in neuroinflammatory diseases (37.3 ± 13.3 ng/mL) compared with NIND (4.7 ± 2.9 ng/mL) and remitting MS (4.6 ± 3.5 ng/mL). Abnormally elevated CSF sCD146 is significantly correlated with the hyperpermeability-related clinical parameters of BBB and neuroinflammation-related factors. Moreover, CSF sCD146 shows higher sensitivity and specificity for evaluating BBB damage. Using an in vitro BBB model, we found that sCD146 impairs BBB function by promoting BBB permeability via an association with integrin ?v?1. Blocking integrin ?v?1 significantly attenuates sCD146-induced hyperpermeability of the BBB. Conclusion: Our study provides convincing evidence that CSF sCD146 is a sensitive marker of BBB damage and neuroinflammation. Furthermore, sCD146 is actively involved in BBB dysfunction.
Project description:Electronic cigarette (e-cigarette) use has grown substantially since inception, particularly among adolescents and combustible tobacco users. Several cigarette smoke constituents with known neurovascular effect are present in e-cigarette liquids or formed during the vapor generation. The present study establishes inhaled models of cigarette and e-cigarette use with normalized nicotine delivery, then characterizes the impact on blood-brain barrier (BBB) function. Sequencing of microvessel RNA following exposure revealed downregulation of several genes with critical roles in BBB function. Reduced protein expression of Occludin and Glut1 is also observed at the tight junction in all groups following exposure. Pro-inflammatory changes in leukocyte-endothelial cell interaction are also noted, and mice exposed to nicotine-free e-cigarettes have impaired novel object recognition performance. On this basis, it is concluded that long term e-cigarette use may adversely impact neurovascular health. The observed effects are noted to be partly independent of nicotine content and nicotine may even serve to moderate the effects of non-nicotinic components on the blood-brain barrier.
Project description:Electronic cigarette (EC) use has grown substantially since entry into the US market, particularly among adolescents and combustible tobacco users. Despite growing popularity and claims of harm reduction, the health effects of these products outside the lung is poorly understood. Several constituents of cigarette smoke (CS) with known neurovascular and inflammatory effects are present in EC liquids or formed during the generation of vapor. The present study characterizes the impact of EC exposure on neuroinflammation and blood-brain barrier (BBB) function, and provides comparison of outcomes with reference cigarette exposure normalized to comparable levels of nicotine delivery. Additionally, the contribution of nicotine to observed effects is elucidated through comparison with EC liquids which are verified to be nicotine-free. C57BL/6 mice are exposed to 2 hrs of daily EC vapor or CS, beginning at 8 wks of age. Changes in BBB gene expression are first characterized by whole exome sequencing of isolated brain microvessels following chronic (2 month) EC exposure.