Hematology and Inflammatory Signaling of Intracerebral Hemorrhage

Background and Purpose-To determine whether the receptor for advanced glycation end-products (RAGE) plays a role in early brain injury from intracerebral hemorrhage (ICH), RAGE expression and activation after injury were examined in a rat model of ICH with or without administration of a RAGE-specific antagonist (FPS-ZM1). Methods-Autologous arterial blood was injected into the basal ganglia of rats to induce ICH. The motor function of the rats was examined, and water content was detected after euthanization. Blood-brain barrier permeability was determined by Evans blue staining and colloidal gold nanoparticle tracers. Nerve fiber injury in white matter was determined by diffusion tensor imaging analysis, and the expression of target genes was analyzed by Western blotting and quantitative reverse transcription polymerase chain reaction. FPS-ZM1 was administered by intraperitoneal injection. Results-Expression of RAGE and its ligand high-mobility group protein B1 were increased at 12 hours after ICH, along with blood-brain barrier permeability and perihematomal nerve fiber injury. RAGE and nuclear factor-κB p65 upregulation were also observed when FeCl 2 was infused into the basal ganglia at 24 hours. FPS-ZM1 administration resulted in significant improvements of blood-brain barrier damage, brain edema, motor dysfunction, and nerve fiber injury, and the expression of RAGE, nuclear factor-κB p65, proinflammatory mediators interleukin 1β, interleukin-6, interleukin-8R, cyclooxygenase-2, inducible nitric oxide synthase, and matrix metallopeptidase-9 was attenuated. Moreover, decreases in claudin-5 and occludin expression were partially recovered. FPS-ZM1 also reversed FeCl 2 -induced RAGE and nuclear factor-κB p65 upregulation. Conclusions-RAGE signaling is involved in blood-brain barrier and white matter fiber damage after ICH, the initiation of which is associated with iron. RAGE antagonists represent a novel therapeutic intervention to prevent early brain injury after ICH. .).The online-only Data Supplement is available with this article at http://stroke.ahajournals.org/lookup/suppl

Section: Discussionmentioning

confidence: 99%

“…26,32 We evaluated white matter fibers in rats after ICH using diffusion tensor imaging analysis and observed white matter fiber bending and reduced FA values in the basal ganglia, indicative of fiber degeneration. 17,19 These changes were accompanied by motor impairment, providing further evidence for functional damage.…”

Section: Discussionmentioning

confidence: 99%

Receptor for Advanced Glycation End-Product Antagonist Reduces Blood–Brain Barrier Damage After Intracerebral Hemorrhage

Yang

Wang

Zhang³

et al. 2015

“…3,23 Leukocyte infiltration can damage vascular endothelium and brain tissue by producing reactive oxygen species, proteases, and proinflammatory mediators. 24,25 It was shown that inflammatory stimuli induced secretion of VWF, 7 leading to leukocyte adhesion and transmigration, which contributes to further amplification and propagation of inflammation.…”

Section: Discussionmentioning

confidence: 99%

Recombinant ADAMTS 13 Attenuates Brain Injury After Intracerebral Hemorrhage

Cai

Luo

et al. 2015

S pontaneous intracerebral hemorrhage (ICH) results from rupture of blood vessels in the brain. It represents ≈10% to 20% of all strokes and is a devastating clinical condition with a 30-day mortality rate of 30% to 55%.1 Currently, there is no proven treatment available for improving ICH outcome. Evidence suggest that ICH is associated with activation of local immune cells and release of inflammatory mediators, which result in enhanced disruption of the blood-brain barrier (BBB), causing an increase in peri-hematomal edema formation and consequent neuronal injury. [2][3][4] Cerebral edema is present in most patients with ICH and is an independent predictor of neurological deterioration.1,2 Therefore, strategies aimed at limiting inflammatory response and BBB dysfunction could be potential therapeutic targets for ICH.von Willebrand factor (VWF) is a multimeric adhesive protein that is released from endothelial Weibel-Palade bodies during injury or inflammation. 5 The multimeric size of VWF is modulated by ADAMTS 13 (a disintegrin and metalloprotease with thrombospondin type I motif, member 13), which processed proteolytically VWF into smaller lessreactive forms. 6 Accumulating data indicate that ADAMTS 13 and VWF play an opposite role in thrombus formation and Background and Purpose-Inflammatory responses and blood-brain barrier (BBB) dysfunction play important roles in brain injury after intracerebral hemorrhage (ICH). The metalloprotease ADAMTS 13 (a disintegrin and metalloprotease with thrombospondin type I motif, member 13) was shown to limit inflammatory responses through its proteolytic effects on von Willebrand factor. In the present study, we addressed the role of ADAMTS 13 after experimental ICH. Methods-ICH was induced in mice by intracerebral infusion of autologous blood. The peri-hematomal inflammatory responses, levels of matrix metalloproteinase-9 and intercellular adhesion molecule-1, pericyte coverage on brain capillaries, and BBB permeability were quantified at 24 hours. Functional outcomes, cerebral edema, and hemorrhagic lesion volume were quantified at day 3. Results-Treatment with recombinant ADAMTS 13 (rADAMTS 13) reduced the levels of chemokines and cytokines, myeloperoxidase activity, and microglia activation and neutrophil recruitment after ICH. rADAMTS 13 also decreased interleukin-6 expression in brain endothelial cells stimulated by lipopolysaccharide, whereas recombinant von Willebrand factor reversed this effect. The anti-inflammatory effect of rADAMTS 13 was accompanied by reduced expression of intercellular adhesion molecule-1 and less activation of matrix metalloproteinase, enhanced pericyte coverage of brain microvessels, and attenuated BBB disruption. Furthermore, neutrophil depletion protected against BBB damage, and rADAMTS 13 treatment had no further beneficial effect. Finally, treatment of mice with rADAMTS 13 reduced cerebral edema and hemorrhagic lesion volume and improved neurological functions. Conclusions-Our findings reveal the importance of rADAMTS 13 in regulating...

“…The formula for calculation was as follows: [(Wet 5 Weight-Dry Weight) / Wet Weight] x 100%. 6 7 Hemoglobin quantification 8 We also detected the amount of extravasated blood in the brain tissue by performing hemoglobin ELISA using a 9 commercial kit (Kamiya Biomedical Company, USA) and a microplate photometer (Thermo Scientific, Varioskan 10 Flash, USA) capable of reading at 450 nm and 570 nm were used to calculate quantity of hemoglobin. 11 12 Isolation of cellular components from CNS and peripheral blood for flow cytometry analysis 13 Brain tissues were mechanically homogenized through a 40 μm nylon cell strainer (Becton Dickinson, Franklin Lakes, 14 NJ, USA) in PBS on ice, then cell suspension was collected and centrifuged at 400 x g for 10 min; the pellet was 15 resuspended in 5 ml of 60 % Percoll (GE Healthcare Bio Science AB, Uppsala, Sweden) and 5 ml 30 % Percoll was 16 overlaid on the top of the 60 % solution.…”

mentioning

confidence: 99%

Selective Sphingosine-1-Phosphate Receptor 1 Modulation Attenuates Experimental Intracerebral Hemorrhage

Sun

Shen

Han

et al. 2016

Intracerebral hemorrhage (ICH) is a devastating disease, which accounts for ≈10% to 15% of strokes with high mortality and morbidity.1,2 Effective treatments for ICH remain sparse.1 Accumulating evidence has demonstrated that brain inflammation provoked by microglia and infiltrating lymphocytes exacerbates ICH-induced brain injury.3 After ICH, brain-intrinsic microglia are the first immune responder and followed by inflammatory infiltrates such as neutrophils, monocytes, macrophages, and subsets of lymphocytes. 4,5 Activation of these cellular components together with factors they produce and cell death products, further contribute to brain inflammation, which results in the development of perihematomal edema.3-7 Perihematomal edema can aggravate the mass effect and secondary brain injury through subsequent oligemia and inflammatory insults.1,8 Edema, as a surrogate marker for inflammation in ICH, 1,9,10 and the persistence of perihematomal edema after ictus makes it amenable for intervention.1 Thus, targeting inflammation could be a viable approach for treating ICH.Sphingosine-1-phosphate (S1P) is a ligand for 5 G-proteincoupled receptors: S1P receptors 1 to 5 (S1PR1-5) are responsible for numerous cell-intrinsic and extrinsic activities. 11,12 Fingolimod (FTY720, Glenya), an oral therapy for multiple sclerosis (MS), is a S1PR modulator that binds to S1PR1, 3, 4, and 5. The beneficial effects of fingolimod in MS may be mediated by S1PR1 expressed on lymphocytes, vascular endothelia, neurons, and glia.11 Recent preclinical and clinical studies have demonstrated that fingolimod can attenuate neurodeficits and brain edema in ICH. [13][14][15][16][17][18] However, it remains unclear whether immune modulations via S1PR1 are sufficient for fingolimod to provide Background and Purpose-Preclinical studies and a proof-of-concept clinical study have shown that sphingosine-1-phosphate receptor (S1PR) modulator, fingolimod, improves the clinical outcome of intracerebral hemorrhage (ICH). However, the specific subtype of the S1PRs through which immune modulation provides protection in ICH remains unclear. In addition, fingolimod-induced adverse effects could limit its use in patients with stroke because of interactions with other S1PR subtypes, particularly with S1PR3. RP101075 is a selective S1PR1 agonist with superior cardiovascular safety profile. In this study, we investigated the impact of RP101075 treatment in a mouse model of ICH. Methods-ICH was induced by injection of autologous blood in 294 male C57BL/6J and Rag2 −/− mice. ICH mice randomly received vehicle, RP101075, or RP101075 plus S1PR1 antagonist W146 by daily oral gavage for three consecutive days, starting from 30 minutes after surgery. Neurodeficits, brain edema, brain infiltration of immune cells, blood-brain barrier integrity, and cell death were assessed after ICH. Results-RP101075 significantly attenuated neurological deficits and reduced brain edema in ICH mice. W146 blocked the effects of RP101075 on neurodeficits and brain edema. RP101075 reduced th...