Search

Supplemental material, sj-pdf-1-jcb-10.1177_0271678X221119288 for Persistent neuroinflammation and behavioural deficits after single mild traumatic brain injury by Antoine Drieu, Anastasia Lanquetin, Paul Prunotto, Zuhal Gulhan, Swannie Pédron, Gloria Vegliante, Daniele Tolomeo, Sophie Serrière, Johnny Vercouillie, Laurent Galineau, Clovis Tauber, Bertrand Kuhnast, Marina Rubio, Elisa R Zanier, Damien Levard, Sylvie Chalon, Denis Vivien and Carine Ali in Journal of Cerebral Blood Flow & Metabolism

Additional file 1: Figure S1. Characterization of a tPA-reporter viral construct in the dentate gyrus. Figure S2. Plat-GFP reporter expression in the cortex after LPS treatment. Figure S3. Plat-GFP reporter expression in excitatory neurons in the cortex. Figure S4. tPA mRNA is expressed in PV interneurons enwrapped with PNNs. Figure S5. Conditional depletion of tPA in PV interneurons. Figure S6. PNN-like structures in vitro. Figure S7. Interneuron-derived tPA promotes PNN degradation through plasmin. Figure S8. tPA/plasmin mediated PNNs degradation is MMP-independent. Table S1. Sequences of PCR primers. Supplementary materials and methods.

Additional file 1: Figure S1. In contrast to tPA coupled to Alexa, Alexa alone is not taken-up by CPECs in vivo. A, Experimental design: mice were injected intravenously with of tPA555 and Alexa488 (50µg each), brains were harvested 30min later for immunohistochemistry. B, Representative confocal photomicrographs (n=4) of CPs sections with tPA555 (magenta), Alexa488 (green) and DAPI (blue) staining; scale bar 50µm (upper panels) and 10µm in the magnified inserts (lower panels). Figure S2. CPECs internalized tPA by clathrin-coated endocytosis vesicles. A, Confocal photomicrographs (representative of n=6 slices) of CPs sections with tPA555 (left bottom, magenta), TTR (left top, white) and AP2 (right top, green) staining; scale bar 50µm and 10µm in the magnified inserts. B, Image analysis of confocal photomicrographs using the Imaris Microscopy Image Analysis Software to study the colocalization between tPA555 and AP2 staining (yellow, right). tPA endocytosis (white arrow); scale bar 10µm. Figure S3. Existence of an efflux pathway for tPA. A, Experimental design: mice received an intra-cerebroventricular injection of tPA555 (1µl at 0.9mg/ml), and brains were harvested 10, 30 or 60min later for immunohistochemistry. B, Representative confocal photomicrographs (n=4) of CPs sections with tPA555 (magenta), LRP1 (green), TTR (white) and DAPI (blue) staining; scale bar 50µm and 10µm in the magnified inserts. Figure S4. Evolution of tPA555 levels in the blood and CSF. A, Experimental design illustrating that mice were injected intravenously with 50µg of tPA555 and BSA488, CSF, blood and brains were harvested 15, 30, or 45min later for protein analysis by electrophoresis (2µl of CSF and 1 µl of plasma were resolved for each animal). B, Representative electrophoreses and C, corresponding quantification for tPA555 levels in the plasma and in the CSF (mean ±SEM, n=5). ** significant difference (p

Delayed cerebral ischemia (DCI) is one of the main prognosis factors for disability after aneurysmal subarachnoid hemorrhage (SAH). The lack of a consensual definition for DCI had limited investigation and care in human until 2010, when a multidisciplinary research expert group proposed to define DCI as the occurrence of cerebral infarction (identified on imaging or histology) associated with clinical deterioration. We performed a systematic review to assess whether preclinical models of SAH meet this definition, focusing on the combination of noninvasive imaging and neurological deficits. To this aim, we searched in PUBMED database and included all rodent SAH models that considered cerebral ischemia and/or neurological outcome and/or vasospasm. Seventy-eight publications were included. Eight different methods were performed to induce SAH, with blood injection in the cisterna magna being the most widely used (n = 39, 50%). Vasospasm was the most investigated SAH-related complication (n = 52, 67%) compared to cerebral ischemia (n = 30, 38%), which was never investigated with imaging. Neurological deficits were also explored (n = 19, 24%). This systematic review shows that no preclinical SAH model meets the 2010 clinical definition of DCI, highlighting the inconsistencies between preclinical and clinical standards. In order to enhance research and favor translation to humans, pertinent SAH animal models reproducing DCI are urgently needed.

Tissue-type plasminogen activator (tPA) a serine protease is constituted of five functional domains through which it interacts with different substrates, binding proteins, and receptors. In the last years, great interest has been given to the clinical relevance of targeting tPA in different diseases of the central nervous system, in particular stroke. Among its reported functions in the central nervous system, tPA displays both neurotrophic and neurotoxic effects. How can the protease mediate such opposite functions remain unclear but several hypotheses have been proposed. These include an influence of the degree of maturity and/or the type of neurons, of the level of tPA, of its origin (endogenous or exogenous) or of its form (single chain tPA versus two chain tPA). In this review, we will provide a synthetic snapshot of our current knowledge regarding the natural history of tPA and discuss how it sustains its pleiotropic functions with focus on excitotoxic/ischemic neuronal death and neuronal survival.

SEE SUN ET AL DOI101093/AWW306 FOR A SCIENTIFIC COMMENTARY ON THIS ARTICLE: About 20% of patients with ischaemic stroke have a preceding transient ischaemic attack, which is clinically defined as focal neurological symptoms of ischaemic origin resolving spontaneously. Failure to diagnose transient ischaemic attack is a wasted opportunity to prevent recurrent disabling stroke. Unfortunately, diagnosis can be difficult, due to numerous mimics, and to the absence of a specific test. New diagnostic tools are thus needed, in particular for radiologically silent cases, which correspond to the recommended tissue-based definition of transient ischaemic attack. As endothelial activation is a hallmark of cerebrovascular events, we postulated that this may also be true for transient ischaemic attack, and that it would be clinically relevant to develop non-invasive in vivo imaging to detect this endothelial activation. Using transcriptional and immunohistological analyses for adhesion molecules in a mouse model, we identified brain endothelial P-selectin as a potential biomarker for transient ischaemic attack. We thus developed ultra-sensitive molecular magnetic resonance imaging using antibody-based microparticles of iron oxide targeting P-selectin. This highly sensitive imaging strategy unmasked activated endothelial cells after experimental transient ischaemic attack and allowed discriminating transient ischaemic attack from epilepsy and migraine, two important transient ischaemic attack mimics. We provide preclinical evidence that combining conventional magnetic resonance imaging with molecular magnetic resonance imaging targeting P-selectin might aid in the diagnosis of transient ischaemic attack.