White Matter Hyperintensity, Immediate Antihypertensive Treatment, and Functional Outcome After Acute Ischemic Stroke.

Background and Purpose- It remains unknown that whether white matter hyperintensity (WMH) severity influences the effect of antihypertensive treatment in acute ischemic stroke. We aimed to investigate the effects of early antihypertensive treatment on death and disability among patients with acute ischemic stroke according to WMH severities. Methods- This study was a secondary analysis of the data from CATIS (China Antihypertensive Trial in Acute Ischemic Stroke). Severity of WMH was evaluated using Fazekas rating scale score among 303 participants with available magnetic resonance imaging data and was categorized into none-mild WMH (Fazekas score 0-2) and moderate-severe WMH (Fazekas score 3-6). Functional outcome was death or major disability (modified Rankin Scale score of ≥3) at 14 days or hospital discharge and within 3 months. Results- WMH severity was significantly associated with an increased risk of death or major disability. Each 1 score increase in Fazekas score was associated with an adjusted odds ratio (95% CI) of 1.25 (1.03-1.51) for 14 days or hospital discharge and 1.39 (1.12-1.72) for 3-month functional outcome. There were no significant interactions between antihypertensive treatment and WMH severity (both P>0.1) on functional outcome at 14 days or hospital discharge and within 3 months. The neutral effects of immediate antihypertensive treatment were observed both in patients with moderate-severe WMH and none-mild WMH. Conclusions- Participants with higher WMH burden had increased risk of death or major disability after acute ischemic stroke. Early antihypertensive treatment had a neutral effect on clinical outcomes among acute ischemic stroke patients with a variety of WMH severities. Registration- URL: https://www.clinicaltrials.gov; Unique identifier: NCT01840072.

Artesunate Attenuates Lipopolysaccharide-Stimulated Proinflammatory Responses by Suppressing TLR4, MyD88 Expression, and NF-κB Activation in Microglial Cells.

Microglia are considered as a major target in the prevention of neuroinflammation by modulating the production of pro-inflammatory mediators. Artesunate, a water-soluble artemisinin derivative, exerts an anti-inflammatory effect. In the present study, we showed artesunate dose-dependently suppressed the lipopolysaccharide (LPS)-induced production of nitric oxide (NO), inducible nitric oxide synthase (iNOS), and interleukin-1beta (IL-1ß) in BV2 microglial cells. In addition, artesunate inhibited LPS-induced expression of Toll-like receptor 4 (TLR4), myeloid differentiation factor 88 (MyD88), and activation of nuclear factor kappa B (NF-κB) by blockade of inhibitor of NF-κB (IκB) degradation. This data indicate that artesunate attenuates the generation of proinflammatory mediators on LPS-stimulated BV-2 microglial cells. And this effect may be associated with the suppression of TLR4/MyD88/NF-κB signaling pathways. Therefore, artesunate may be a potential anti-neuroinflammatory agent.

Soluble vascular endothelial growth factor (VEGF) receptor-1 inhibits migration of human monocytic THP-1 cells in response to VEGF.

OBJECTIVE: We aimed to investigate the regulation and contribution of vascular endothelial growth factor (VEGF) and sFlt-1(1-3) to human monocytic THP-1 migration. MATERIALS AND METHODS: Ad-sFlt-1/FLAG, a recombinant adenovirus carrying the human sFlt-1(1-3) (the first three extracellular domains of FLT-1, the hVEGF receptor-1) gene, was constructed. L929 cells were infected with Ad-sFlt-1/FLAG and the expression of sFlt-1 was detected by immunofluorescent assay and ELISA. Corning(®) Transwell(®) Filter Inserts containing polyethylene terephthalate (PET) membranes with pore sizes of 3 µm were used as an experimental model to simulate THP-1 migration. Five VEGF concentrations (0, 0.1, 1, 10 and 100 ng/ml), four concentrations of sFlt-1(1-3)/FLAG expression supernatants (0.1, 1, 10 and 100 ng/ml), and monocyte chemoattractant protein-1 (MCP-1, 10 ng/ml) were used to test the ability of THP-1 cells to migrate through PET membranes. RESULTS: The sFlt-1(1-3) gene was successfully recombined into Ad-sFlt-1/FLAG. sFlt-1(1-3) was expressed in L929 cells transfected with Ad-sFlt-1/FLAG. THP-1 cell migration increased with increasing concentrations of VEGF, while cell migration decreased with increasing concentrations of sFlt1(1-3)/FLAG. sFlt1(1-3)/FLAG had no effect on MCP-1-induced cell migration. CONCLUSIONS: This study demonstrated that VEGF is able to elicit a migratory response in THP-1 cells, and that sFlt-1(1-3) is an effective inhibitor of THP-1 migration towards VEGF.

Macrolide antibiotics aggravate experimental autoimmune encephalomyelitis and inhibit inducible nitric oxide synthase.

Recent studies have implicated Chlamydia pneumoniae (C. pneumoniae) is present in a subset of patients with multiple sclerosis (MS) in which C. pneumoniae could act as a cofactor in the development of the disease. Macrolide antibiotics are most widely used anti-chlamydial agents and have immunomodulatory effect independently of their anti-bacterial activity. To investigate their effects on experimental autoimmune encephalomyelitis (EAE), EAE was induced by immunization with MBP68-86 peptide emulsified in complete Freund's adjuvant (CFA). Clarithromycin (CM) or azithromycin (AM, 50 mg/100 g body weight) was administrated daily from day 2 before immunization. All rats developed and survived EAE, but the groups administrated CM or AM had more severe symptoms. On day 11 post-immunization, mononuclear cells (MNCs) were prepared from the spleen of control group and cultured with or without macrolide antibiotics (10mug/ml). We evaluated nitric oxide (NO) production in the serum and culture supernatant. Inducible nitric oxide synthase (iNOS) mRNA and protein expression in the spinal cords and cultured MNCs were measured. The results showed that CM and AM similarly inhibited NO production and iNOS mRNA and protein expression in vivo and in vitro. Macrolide antibiotics may aggravate EAE by inhibiting iNOS mRNA and protein expression. Further studies are needed to investigate the effect of macrolide antibiotics on MS and to compare the effect of different anti-chlamydial antibiotics on MS.

Overexpression of CNTF in Mesenchymal Stem Cells reduces demyelination and induces clinical recovery in experimental autoimmune encephalomyelitis mice.

Human Mesenchymal Stem Cells (MSCs) were previously reported to ameliorate neuronal functional deficits in the MOG35-55-induced experimental autoimmune encephalomyelitis (EAE) mice by inducing T cell anergy. Human Ciliary neurotrophic factor (CNTF) recently was found to promote myelogenesis and reduce inflammation in CNTF-deficient EAE mice. We ectopically overexpressed CNTF in human MSCs to investigate its potential role in promoting remyelination and improving functional recovery in EAE mice. MSCs transfected by Ad-CNTF-IRES-EGFP (MSC-CNTF) were injected intravenously into EAE mice 10 days after the immunization. Neurological functional tests were scored daily by grading clinical signs (score 0-6). Immunofluorescence microscopy was used to detect MSC-CNTF in spinal cord. Expression of NG2, CNTF, and cleaved caspase-3 was measured by immunohistochemistry. CNTF expression was also analyzed by Western blot. Myelin was detected by Solochrome Cyanin staining. Our results found that CNTF concentration in MSC-CNTF cells was 20-fold higher than that in either MSC or Ad-EGFP-transfected MSCs (MSC-EGFP) in vitro. Mice receiving MSC-CNTF cells showed remarkable neuronal functional recovery: the cumulative clinical scores were significantly decreased, and the disease onset was statistically delayed. Mice receiving MSC-CNTF cells showed reduced TNF-alpha, IFN-gamma and increased the level of cytokine IL-10 in peripheral blood and a large number of MSC-CNTF cells were detected in the spleen, but were not detected in other organs such as lung, liver and kidney. In the lesions of these mice, 1) the number of cleaved caspase3-positive cells was significantly reduced; 2) MSC-CNTF- and NG2-positive cells were significantly increased; and 3) the expression of CNTF was dramatically increased. In addition, demyelination was significantly reduced in MSC-CNTF mice. These data indicated that MSC-CNTF may improve functional recovery in EAE mice, possibly by exerting their immunoregulatory activity, inhibiting inflammation, homing MSC-CNTF cells to the lesions, elevating CNTF expression, reducing demyelination, and stimulating oligodendrogenesis.

Adenoviral delivery of soluble VEGF receptor 1 (sFlt-1) inhibits experimental autoimmune encephalomyelitis in dark Agouti (DA) rats.

Previous studies have shown that vascular endothelial growth factor (VEGF) expression is up-regulated in both multiple sclerosis (MS) and experimental autoimmune encephalomyelitis (EAE), a model for MS, and may exacerbate the disease. However, it remains unknown whether anti-VEGF modalities could serve as a potential treatment for such central nervous system (CNS) autoimmune diseases. We constructed a recombinant adenoviral vector carrying FLAG-tagged sFlt-1(1-3) (the first three extracellular domains of Flt-1, the hVEGF receptor-1). Intramuscular transfection of the recombinant adenoviral vector suppressed VEGF-induced inflammatory cell infiltration in matrigel plugs. When given intracerebrally to EAE rats, recombinant sFlt-1(1-3) adenoviral vector significantly reduced disease severity compared to untreated rats. sFlt-1(1-3) gene transfer blocked VEGF and greatly reduced the number of cells that express VEGF and ED1-positive cells in CNS in EAE rats. This study demonstrates that sFlt-1(1-3) gene transfer into the brain ameliorates the severity of EAE by inhibiting monocyte recruitment in the CNS of dark Agouti rats.