A single mild juvenile TBI in male mice leads to regional brain tissue abnormalities at 12 months of age that correlate with cognitive impairment at the middle age.

Traumatic brain injury (TBI) has the highest incidence amongst the pediatric population and its mild severity represents the most frequent cases. Moderate and severe injuries as well as repetitive mild TBI result in lasting morbidity. However, whether a single mild TBI sustained during childhood can produce long-lasting modifications within the brain is still debated.

Early cerebrovascular and long-term neurological modifications ensue following juvenile mild traumatic brain injury in male mice.

Clinical evidence suggests that a mild traumatic brain injury occurring at a juvenile age (jmTBI) may be sufficient to elicit pathophysiological modifications. However, clinical reports are not adequately integrated with experimental studies examining brain changes occurring post-jmTBI. We monitored the cerebrovascular modifications and assessed the long-term behavioral and electrographic changes resulting from experimental jmTBI.

Juvenile mild traumatic brain injury elicits distinct spatiotemporal astrocyte responses.

Mild-traumatic brain injury (mTBI) represents ~80% of all emergency room visits and increases the probability of developing long-term cognitive disorders in children. To date, molecular and cellular mechanisms underlying post-mTBI cognitive dysfunction are unknown. Astrogliosis has been shown to significantly alter astrocytes' properties following brain injury, potentially leading to significant brain dysfunction.

Aquaporins in brain edema.

Brain edema is a common feature of brain injuries, which leads to increased intracranial pressure (ICP) and ischemia that worsen outcome. Current management of edema focuses on reduction of ICP, but there are no treatments targeting the molecular players directly involved in edema process. The perivascular astrocyte endfeet are critical in maintaining brain homeostasis with ionic and water exchange; in this context, aquaporins (AQPs), astrocyte water channels, have emerged as privileged targets for edema modulation.

Gliovascular changes precede white matter damage and long-term disorders in juvenile mild closed head injury.

Traumatic brain injury (TBI) is a leading cause of hospital visits in pediatric patients and often leads to long-term disorders even in cases of mild severity. White matter (WM) alterations are commonly observed in patients months or years after the injury assessed by magnetic resonance imaging (MRI), but little is known about WM pathophysiology early after mild pediatric TBI. To evaluate the status of the gliovascular unit in this context, mild TBI was induced in postnatal-day 17 mice using a closed head injury model with two grades of severity (G1, G2).

Early to Long-Term Alterations of CNS Barriers After Traumatic Brain Injury: Considerations for Drug Development.

Traumatic brain injury (TBI) is one of the leading causes of death and disability, particularly amongst the young and the elderly. The functions of the blood-brain barrier (BBB) and blood-cerebrospinal fluid barrier (BCSFB) are strongly impaired after TBI, thus affecting brain homeostasis. Following the primary mechanical injury that characterizes TBI, a secondary injury develops over time, including events such as edema formation, oxidative stress, neuroinflammation, and alterations in paracelullar and transcellular transport.

Gas Diffusion in the CNS.

Gases have been long known to have essential physiological functions in the CNS such as respiration or regulation of vascular tone. Since gases have been classically considered to freely diffuse, research in gas biology has so far focused on mechanisms of gas synthesis and gas reactivity, rather than gas diffusion and transport. However, the discovery of gas pores during the last two decades and the characterization of diverse diffusion patterns through different membranes has raised the possibility that modulation of gas diffusion is also a physiologically relevant parameter.

Vascular impairment as a pathological mechanism underlying long-lasting cognitive dysfunction after pediatric traumatic brain injury.

Traumatic brain injury (TBI) is the leading cause of death and disability in children. Indeed, the acute mechanical injury often evolves to a chronic brain disorder with long-term cognitive, emotional and social dysfunction even in the case of mild TBI. Contrary to the commonly held idea that children show better recovery from injuries than adults, pediatric TBI patients actually have worse outcome than adults for the same injury severity.

Pentraxin 3 mediates neurogenesis and angiogenesis after cerebral ischaemia.

Background: The acute phase protein pentraxin 3 (PTX3) is a new biomarker of stroke severity and is a key regulator of oedema resolution and glial responses after cerebral ischaemia, emerging as a possible target for brain repair after stroke. Neurogenesis and angiogenesis are essential events in post-stroke recovery. Here, we investigated for the first time the role of PTX3 in neurogenesis and angiogenesis after stroke.

The acute-phase protein PTX3 is an essential mediator of glial scar formation and resolution of brain edema after ischemic injury.

Acute-phase proteins (APPs) are key effectors of the immune response and are routinely used as biomarkers in cerebrovascular diseases, but their role during brain inflammation remains largely unknown. Elevated circulating levels of the acute-phase protein pentraxin-3 (PTX3) are associated with worse outcome in stroke patients. Here we show that PTX3 is expressed in neurons and glia in response to cerebral ischemia, and that the proinflammatory cytokine interleukin-1 (IL-1) is a key driver of PTX3 expression in the brain after experimental stroke.

Activation of brain endothelial cells by interleukin-1 is regulated by the extracellular matrix after acute brain injury.

The extracellular matrix (ECM) of the central nervous system (CNS) is essential for normal brain function, whilst ECM remodelling is associated with cerebrovascular inflammation driven by the cytokine interleukin-1 (IL-1) after acute brain injury. The effect of ECM remodelling on endothelial activation during neuroinflammation remains unknown. Here we report that ECM remodelling in the cerebrovasculature critically regulates IL-1-induced endothelial cell activation after cerebral ischaemia; Expression levels of ECM molecules associated with the cerebrovasculature, namely fibronectin (FN) and collagen IV (Col IV), strongly increased in brain blood vessels after middle cerebral artery occlusion (MCAo) in a time-dependent manner, reaching a peak of vascular expression 48 h after MCAo.

The immune system in stroke: clinical challenges and their translation to experimental research.

Stroke represents an unresolved challenge for both developed and developing countries and has a huge socio-economic impact. Although considerable effort has been made to limit stroke incidence and improve outcome, strategies aimed at protecting injured neurons in the brain have all failed. This failure is likely to be due to both the incompleteness of modelling the disease and its causes in experimental research, and also the lack of understanding of how systemic mechanisms lead to an acute cerebrovascular event or contribute to outcome.

Loss of substance P and inflammation precede delayed neurodegeneration in the substantia nigra after cerebral ischemia.

Focal cerebral ischemia leads to delayed neurodegeneration in remote brain regions. The substantia nigra (SN) does not normally show primary neuronal death after ischemic events affecting the striatum, but can exhibit delayed neuronal loss after the ischemic injury through mechanisms that are unknown. No data are available in mice showing acute post-stroke inflammation and remote injury in the SN.