Dataset Information

Modulators of microglial activation and polarization after intracerebral haemorrhage.

ABSTRACT: Intracerebral haemorrhage (ICH) is the most lethal subtype of stroke but currently lacks effective treatment. Microglia are among the first non-neuronal cells on the scene during the innate immune response to ICH. Microglia respond to acute brain injury by becoming activated and developing classic M1-like (proinflammatory) or alternative M2-like (anti-inflammatory) phenotypes. This polarization implies as yet unrecognized actions of microglia in ICH pathology and recovery, perhaps involving microglial production of proinflammatory or anti-inflammatory cytokines and chemokines. Furthermore, alternatively activated M2-like microglia might promote phagocytosis of red blood cells and tissue debris, a major contribution to haematoma clearance. Interactions between microglia and other cells modulate microglial activation and function, and are also important in ICH pathology. This Review summarizes key studies on modulators of microglial activation and polarization after ICH, including M1-like and M2-like microglial phenotype markers, transcription factors and key signalling pathways. Microglial phagocytosis, haematoma resolution, and the potential crosstalk between microglia and T lymphocytes, neurons, astrocytes, and oligodendrocytes in the ICH brain are described. Finally, the clinical and translational implications of microglial polarization in ICH are presented, including the evidence that therapeutic approaches aimed at modulating microglial function might mitigate ICH injury and improve brain repair.

SUBMITTER: Lan X

PROVIDER: S-EPMC5575938 | biostudies-other | 2017 Jul

REPOSITORIES: biostudies-other

ACCESS DATA

Publications

Modulators of microglial activation and polarization after intracerebral haemorrhage.

Lan Xi X Han Xiaoning X Li Qian Q Yang Qing-Wu QW Wang Jian J

Nature reviews. Neurology 20170519 7

Intracerebral haemorrhage (ICH) is the most lethal subtype of stroke but currently lacks effective treatment. Microglia are among the first non-neuronal cells on the scene during the innate immune response to ICH. Microglia respond to acute brain injury by becoming activated and developing classic M1-like (proinflammatory) or alternative M2-like (anti-inflammatory) phenotypes. This polarization implies as yet unrecognized actions of microglia in ICH pathology and recovery, perhaps involving micr ...[more]

PMID: 28524175

Similar Datasets

Project description:Late seizures after intracerebral haemorrhage occur after the initial acute haemorrhagic insult subsides, and represent one of its most feared long-term sequelae. Both susceptibility to late seizures and their functional impact remain poorly characterized. We sought to: (i) compare patients with new-onset late seizures (i.e. delayed seizures), with those who experienced a recurrent late seizure following an immediately post-haemorrhagic seizure; and (ii) investigate the effect of late seizures on long-term functional performance after intracerebral haemorrhage. We performed prospective longitudinal follow-up of consecutive intracerebral haemorrhage survivors presenting to a single tertiary care centre. We tested for association with seizures the following neuroimaging and genetic markers of cerebral small vessel disease: APOE variants ?2/?4, computer tomography-defined white matter disease, magnetic resonance imaging-defined white matter hyperintensities volume and cerebral microbleeds. Cognitive performance was measured using the Modified Telephone Interview for Cognitive Status, and functional performance using structured questionnaires obtained every 6 months. We performed time-to-event analysis using separate Cox models for risk to develop delayed and recurrent seizures, as well as for functional decline risk (mortality, incident dementia, and loss of functional independence) after intracerebral haemorrhage. A total of 872 survivors of intracerebral haemorrhage were enrolled and followed for a median of 3.9 years. Early seizure developed in 86 patients, 42 of whom went on to experience recurrent seizures. Admission Glasgow Coma Scale, increasing haematoma volume and cortical involvement were associated with recurrent seizure risk (all P < 0.01). Recurrent seizures were not associated with long-term functional outcome (P = 0.67). Delayed seizures occurred in 37 patients, corresponding to an estimated incidence of 0.8% per year (95% confidence interval 0.5-1.2%). Factors associated with delayed seizures included cortical involvement on index haemorrhage (hazard ratio 1.63, P = 0.036), pre-haemorrhage dementia (hazard ratio 1.36, P = 0.044), history of multiple prior lobar haemorrhages (hazard ratio 2.50, P = 0.038), exclusively lobar microbleeds (hazard ratio 2.22, P = 0.008) and presence of ? 1 APOE ?4 copies (hazard ratio 1.95, P = 0.020). Delayed seizures were associated with worse long-term functional outcome (hazard ratio 1.83, P = 0.005), but the association was removed by adjusting for neuroimaging and genetic markers of cerebral small vessel disease. Delayed seizures after intracerebral haemorrhage are associated with different risk factors, when compared to recurrent seizures. They are also associated with worse functional outcome, but this finding appears to be related to underlying small vessel disease. Further investigations into the connections between small vessel disease and delayed seizures are warranted.

Project description:BackgroundOutcome after spontaneous (non-traumatic) intracerebral haemorrhage (ICH) is influenced by haematoma volume; up to one-third of ICHs enlarge within 24 hours of onset. Early haemostatic therapy might improve outcome by limiting haematoma growth. This is an update of a Cochrane Review first published in 2006, and last updated in 2009.ObjectivesTo examine 1) the effectiveness and safety of individual classes of haemostatic therapies, compared against placebo or open control, in adults with acute spontaneous intracerebral haemorrhage, and 2) the effects of each class of haemostatic therapy according to the type of antithrombotic drug taken immediately before ICH onset (i.e. anticoagulant, antiplatelet, or none).Search methodsWe searched the Cochrane Stroke Trials Register, CENTRAL; 2017, Issue 11, MEDLINE Ovid, and Embase Ovid on 27 November 2017. In an effort to identify further published, ongoing, and unpublished randomised controlled trials (RCT), we scanned bibliographies of relevant articles and searched international registers of RCTs in November 2017.Selection criteriaWe sought randomised controlled trials (RCTs) of any haemostatic intervention (i.e. pro-coagulant treatments such as coagulation factors, antifibrinolytic drugs, or platelet transfusion) for acute spontaneous ICH, compared with placebo, open control, or an active comparator, reporting relevant clinical outcome measures.Data collection and analysisTwo authors independently extracted data, assessed risk of bias, and contacted corresponding authors of eligible RCTs for specific data if they were not provided in the published report of an RCT.Main resultsWe included 12 RCTs involving 1732 participants. There were seven RCTs of blood clotting factors versus placebo or open control involving 1480 participants, three RCTs of antifibrinolytic drugs versus placebo or open control involving 57 participants, one RCT of platelet transfusion versus open control involving 190 participants, and one RCT of blood clotting factors versus fresh frozen plasma involving five participants. We were unable to include two eligible RCTs because they presented aggregate data for adults with ICH and other types of intracranial haemorrhage. We identified 10 ongoing RCTs. Across all seven criteria in the 12 included RCTs, the risk of bias was unclear in 37 (44%), high in 16 (19%), and low in 31 (37%). Only one RCT was at low risk of bias in all criteria.In one RCT of platelet transfusion versus open control for acute spontaneous ICH associated with antiplatelet drug use, there was a significant increase in death or dependence (modified Rankin Scale score 4 to 6) at day 90 (70/97 versus 52/93; risk ratio (RR) 1.29, 95% confidence interval (CI) 1.04 to 1.61, one trial, 190 participants, moderate-quality evidence). All findings were non-significant for blood clotting factors versus placebo or open control for acute spontaneous ICH with or without surgery (moderate-quality evidence), for antifibrinolytic drugs versus placebo (moderate-quality evidence) or open control for acute spontaneous ICH (moderate-quality evidence), and for clotting factors versus fresh frozen plasma for acute spontaneous ICH associated with anticoagulant drug use (no evidence).Authors' conclusionsBased on moderate-quality evidence from one trial, platelet transfusion seems hazardous in comparison to standard care for adults with antiplatelet-associated ICH.We were unable to draw firm conclusions about the efficacy and safety of blood clotting factors for acute spontaneous ICH with or without surgery, antifibrinolytic drugs for acute spontaneous ICH, and clotting factors versus fresh frozen plasma for acute spontaneous ICH associated with anticoagulant drug use.Further RCTs are warranted, and we await the results of the 10 ongoing RCTs with interest.

Dataset Information

Modulators of microglial activation and polarization after intracerebral haemorrhage.

Publications

Modulators of microglial activation and polarization after intracerebral haemorrhage.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets