Imaging of Microglia Activation in Stroke

  title={Imaging of Microglia Activation in Stroke},
  author={Alexander Thiel and W.-D. Heiss},
Activated microglia is one of the most important cellular components of poststroke neuroinflammation, which occurs early in the area of the infarct but also in remote regions with fiber tract connections to the site of the primary lesion. The development of different radioligands for the translocator protein, a mitochondrial membrane protein expressed in microglial cells when they transform from the resting to the activated state, allows to study the temporal dynamics of this cellular… 

Figures from this paper

In Vivo Imaging of Neuroinflammation in Acute Brain Injury

This chapter is an introduction into the basic principles of microglia imaging with PET, its application to ischaemic stroke and traumatic brain injury in both animal models and clinical imaging in patients and future developments towards magnetic resonance imaging of neuroinflammation and imaging of specific enzyme activity in the neuroinflammatory cascade are discussed.

Imaging neuroinflammation in ischemic stroke and in the atherosclerotic vascular disease.

The aim of this review is to discuss the most recent knowledge about imaging neuroinflammation in ischemic stroke and in the atherosclerotic and vascular inflammatory disorders, trying to elucidate the interplay between the clinical course and the activation of a microglial response.

In vivo imaging of activated microglia in a mouse model of focal cerebral ischemia by two-photon microscopy.

In vivo TPM imaging of ICW would be a useful tool to screen for therapeutic interventions lowering microglial activation hence neuroinflammation and indomethacin, a non-steroidal anti-inflammatory drug significantly attenuated CD68-positive microglia activation in ICW, which was further confirmed by qRT-PCR biochemical analyses.

Polarization of Microglia/Macrophages in Brain Ischaemia: Relevance for Stroke Therapy

The innate immune system plays a pivotal role in ischemic stroke pathobiology, involving soluble and cellular mediators activated locally or recruited from the periphery, and can eventually turn into a round amoeboid phenotype morphologically indistinguishable from blood-derived macrophages.

Longitudinal monitoring of microglial/macrophage activation in ischemic rat brain using Iba-1-specific nanoparticle-enhanced magnetic resonance imaging

The results suggest that nanoparticle-enhanced MRI may constitute a novel approach for monitoring the dynamic development of neuroinflammation in living animals during the progression and treatment of stroke.

Microglial Polarization: Novel Therapeutic Strategy against Ischemic Stroke

The process of microglial polarization is discussed, the alternation of signaling pathways and epigenetic regulation that control microglian polarization in ischemic stroke is summarized, and the potential mechanisms by which microglia can be transformed into the M2 polarized phenotype are found.

Microglial Responses to Brain Injury and Disease: Functional Diversity and New Opportunities

Microglia-targeted therapeutic opportunities are described, including pharmacologic modulation of phenotype and repopulation of the brain with fresh microglia, which may translate into potential therapeutics against brain injury and neurological disease.

The biphasic function of microglia in ischemic stroke

New Insights Into the Roles of Microglial Regulation in Brain Plasticity-Dependent Stroke Recovery

This review focuses on the crosstalk between microglial activation and endogenous neuroplasticity, with a special focus on the plastic alterations in the whole brain network and their implications for structural and functional restoration after stroke.



In vivo imaging of activated microglia using [11 C]PK11195 and positron emission tomography in patients after ischemic stroke

This PET method is considered as a promising tool to study the late pathogenetic consequences of cerebral infarction and to evaluate neuroprotective strategies with respect to the consequences of the microglial activation.

Imaging Microglial Activation During Neuroinflammation and Alzheimer’s Disease

Imaging microglia in vivo in live subjects by confocal or two/multiphoton microscopy offers the advantage of studying these cells over time in their native environment, and can offer a measure of the inflammatory process and a means of detecting progression of disease and efficacy of therapeutics over time.

Intrinsic Activated Microglia Map to the Peri-infarct Zone in the Subacute Phase of Ischemic Stroke

In ischemic stroke patients, minimal activation of microglia is seen before 72 hours and extending to 30 days in core infarction, contralateral hemisphere, and peri-infarct zone, suggesting a therapeutic opportunity that extends beyond time windows traditionally reserved for neuroprotection.

Imaging Inflammation in Acute Brain Ischemia

Iron oxide nanoparticles such as ultrasmall superparamagnetic iron oxide (USPIO) are novel cell-specific contrast agents for MRI, and USPIO-laden macrophages cause typical signal changes in MRI of infarcted brain parenchyma, which has been demonstrated in studies of both experimental ischemia and human stroke.

Microglia in ischemic brain injury.

Microglia are resident CNS immune cells that are active sensors in healthy brain and versatile effectors under pathological conditions. Cerebral ischemia induces a robust neuroinflammatory response

In vivo imaging of neuroinflammation

Proliferating Resident Microglia after Focal Cerebral Ischaemia in Mice

  • Á. DénesR. Vidyasagar S. Allan
  • Biology
    Journal of cerebral blood flow and metabolism : official journal of the International Society of Cerebral Blood Flow and Metabolism
  • 2007
Interestingly, the more severe injury associated with 60 mins of MCAo leads to a markedly reduced proliferation of resident microglial cells, suggesting that these cells may play a protective function, possibly through phagocytosis of infiltrating neutrophils, which further support possible beneficial actions of microglia cells in the injured brain.

Microglia: active sensor and versatile effector cells in the normal and pathologic brain

This review focuses on several key observations that illustrate the multi-faceted activities of microglia in the normal and pathologic brain.

The Temporal Dynamics of Poststroke Neuroinflammation: A Longitudinal Diffusion Tensor Imaging–Guided PET Study with 11C-PK11195 in Acute Subcortical Stroke

DTI-guided 11C-PK11195 PET in acute subcortical stroke demonstrates differential temporal dynamics of local and remote AMG, which might contribute differently to clinical outcome.