Publications by authors named "Peter Theriault"

Alzheimer's disease (AD) pathology is characterized by amyloid-β (Aβ) deposition and tau hyper-phosphorylation, accompanied by a progressive cognitive decline. Monocytes have been recently shown to play a major role in modulating Aβ pathology, and thereby have been pointed as potential therapeutic targets. However, the main challenge remains in identifying clinically relevant interventions that could modulate monocyte immune functions in absence of undesired off-target effects.

View Article and Find Full Text PDF

The signals that regulate the fate of circulating monocytes remain unknown. In the present study, we demonstrate that triggering of the NOD2 receptor by muramyl dipeptide (MDP) converts inflammatory Ly6C monocytes into patrolling Ly6C monocytes. Administration of MDP to Nr4a1 mice, which lack Ly6C monocytes, or to Ly6C-depleted mice led to the emergence of blood-patrolling monocytes with a profile similar to that of Ly6C monocytes, including high expression of CX3CR1 and LFA1.

View Article and Find Full Text PDF

Alzheimer's disease (AD) is mainly characterized by the accumulation and aggregation of amyloid-β (Aβ) peptides in brain parenchyma and cerebral microvasculature. Unfortunately, the exact causes of the disease are still unclear. However, blood-brain barrier (BBB) dysfunction and activation of inflammatory pathways are implicated in AD pathogenesis.

View Article and Find Full Text PDF

Growing evidence highlights the crucial physiological functions of microglia that rely on their phagocytic activities, which can be compromised with age. A new study reports the impaired clearance of myelin debris by microglia in the brain, leading to insoluble lysosomal inclusions and contributing to the immune dysfunction and senescence of these cells.

View Article and Find Full Text PDF

Stroke is associated with neuroinflammation, neuronal loss and blood-brain barrier (BBB) breakdown. Thus far, recombinant tissue-type plasminogen activator (rtPA), the only approved treatment for acute ischemic stroke, increases the risk of intracerebral hemorrhage and is poorly efficient in disaggregating platelet-rich thrombi. Therefore, the development of safer and more efficient therapies is highly awaited.

View Article and Find Full Text PDF

Alzheimer's disease (AD) is the leading cause of dementia among elderly population. AD is characterized by the accumulation of beta-amyloid (Aβ) peptides, which aggregate over time to form amyloid plaques in the brain. Reducing soluble Aβ levels and consequently amyloid plaques constitute an attractive therapeutic avenue to, at least, stabilize AD pathogenesis.

View Article and Find Full Text PDF

Alzheimer's disease (AD) is the most common neurodegenerative disorder affecting older people worldwide. It is a progressive disorder mainly characterized by the presence of amyloid-beta (Aβ) plaques and neurofibrillary tangles within the brain parenchyma. It is now well accepted that neuroinflammation constitutes an important feature in AD, wherein the exact role of innate immunity remains unclear.

View Article and Find Full Text PDF

Neurons are extremely vulnerable cells that tightly rely on the brain's highly dynamic and complex vascular network that assures an accurate and adequate distribution of nutrients and oxygen. The neurovascular unit (NVU) couples neuronal activity to vascular function, controls brain homeostasis, and maintains an optimal brain microenvironment adequate for neuronal survival by adjusting blood-brain barrier (BBB) parameters based on brain needs. The NVU is a heterogeneous structure constituted by different cell types that includes pericytes.

View Article and Find Full Text PDF

Background: The Blood-brain barrier (BBB) controls brain supply with oxygen and nutrients, and protects the brain from toxic metabolites, such as beta-amyloid (Aβ) peptides. The neurovascular unit (NVU) couples vascular and neuronal functions by controlling BBB parameters based on brain needs. As such, NVU/BBB dysfunction, associated to irregularities in cerebral blood flow (CBF), has been proposed to contribute in the pathogenesis of Alzheimer's disease (AD), mainly by impairing cerebral Aβ clearance.

View Article and Find Full Text PDF

Alzheimer's disease (AD) is the most common cause of dementia worldwide. The pathogenesis of this neurodegenerative disease, currently without curative treatment, is associated with the accumulation of amyloid β (Aβ) in brain parenchyma and cerebral vasculature. AD patients are unable to clear this toxic peptide, leading to Aβ accumulation in their brains and, presumably, the pathology associated with this devastating disease.

View Article and Find Full Text PDF

3xTg-AD mutant mice are characterized by parenchymal Aβ plaques and neurofibrillary tangles resembling those found in patients with Alzheimer's disease. The mutants were compared with non-transgenic controls in sensorimotor and learning tests. 3xTg-AD mutants were deficient in T-maze reversal, object recognition, and passive avoidance learning.

View Article and Find Full Text PDF