intracerebroventricular-intravascular-injection-viral-particles

Intracerebroventricular and Intravascular Injection of Viral Particles and Fluorescent Microbeads into the Neonatal Brain

In the study on the pathogenesis of viral encephalitis, the infection method is critical. The first of the two main infectious routes to the brain is the ...

Hamamatsu University School of Medicine

Congenital cytomegalovirus (CMV) infection is the leading viral cause of neurodevelopmental disorders in humans, with the most severe and permanent sequelae being those affecting the cerebrum. As the fetal immune reactions to congenital CMV infection in the brain and their effects on cerebral development remain elusive, our aim was to investigate primitive innate immunity to CMV infection and its effects on cerebral corticogenesis in a mouse model for congenital CMV infection using a precise intraplacental inoculation method.

Aberrant fetal macrophage/microglial reactions to cytomegalovirus infection.

Cytomegalovirus (CMV) is a prevalent pathogen in intrauterine infections that causes congenital anomalies such as CMV encephalitis, which is characterized by the focal areas of reactive gliosis, reactive mononuclear cells, microglial nodules, and ventriculoencephalitis. To elucidate the mechanisms of CMV susceptibility in the developing brain, cell tropism and the infectious dynamics of CMV infection were investigated. We evaluated intraventricular and intravascular infections from the perspective of the distribution of CMV and its receptor (β1 integrin) in the earliest phase of infection. Murine CMV (MCMV) immediate early 1-positive cells were colocalized mainly with meninges and choroid plexus (after intraventricular infection) or with endothelial cells and pericytes (after intravascular infection). Using green fluorescent protein-expressing recombinant MCMV particles and fluorescent microbeads (100 to 300 nm), we revealed that CMV particle size is the primary factor determining the initial CMV distribution. β1 Integrin inhibition using a shRNA and functional blocking antibody significantly reduced MCMV infection. IHC analysis, flow cytometric, and brain slice analyses strongly support that high-level β1 integrin-expressing cells (eg, endothelial cells, pericytes, meninges, choroid plexus, and neural stem progenitor cells) are the first targets of MCMV. Therefore, our data demonstrate that the initial distributions of MCMV particles and β1 integrin determine the distinct pattern of infection in the brain in the acute phase.

Cytomegalovirus initiates infection selectively from high-level β1 integrin-expressing cells in the brain.

Idiopathic hypoparathyroidism (IHP) is accompanied by cognitive impairment. We report the case of a 70-year-old IHP patient with cognitive disturbance. Brain computed tomography showed bilateral calcification in basal ganglia, thalamus, and cerebellum. Neuropsychological assessment revealed low scores for intelligence, memory, and perseverative errors. Brain positron emission tomography showed a significant reduction in [(18)F]-Fludeoxyglucose (FDG) uptake in bilateral frontal, left temporal and parietal cortices, along with a marked reduction in [(11)C]-flumazenil binding in left frontal, temporal, parietal, and bilateral cerebellum. These findings suggest cognitive impairment in IHP may be ascribed to GABAergic dysfunction, thus leading to, or coexisting with, cerebral hypometabolism.

Article	Year
Aberrant fetal macrophage/microglial reactions to cytomegalovirus infection. Annals of clinical and translational neurology\| PubMed ID: 25356429	2014
Cytomegalovirus initiates infection selectively from high-level β1 integrin-expressing cells in the brain. The American journal of pathology\| PubMed ID: 25797647	2015
The Possible Link between GABAergic Dysfunction and Cognitive Decline in a Patient with Idiopathic Hypoparathyroidism. Internal medicine (Tokyo, Japan)\| PubMed ID: 26328655	2015

Makiko Sakao-Suzuki

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