myelin-basic-protein and Developmental-Disabilities

Hypoxic-ischemic (HI) injury to the developing brain remains a major cause of morbidity. To date, few therapeutic strategies could provide complete neuroprotection. Erythropoietin (EPO) has been shown to be beneficial in several models of neonatal HI. This study examines the effect of treatment with erythropoietin on postnatal day 2 (P2) rats introduced with HI injury.. Rats at P2 were randomized into four groups: sham, bilateral carotid artery occlusion (BCAO), BCAO + early EPO, and BCAO + late EPO groups. Pups in each group were injected with either saline or EPO (5000U/kg) intraperitoneally once at immediately (early) or 48h (late) after HI induction. Body weight was assessed at P2 before and day 7 after HI. Mortality Rate was assessed at 24h, 48h and 72h after HI and brain water content was assessed at 72h. Brain weight and expression of myelin basic protein (MBP) were assessed at day 7 and day 14. At day 31 to 35 following HI insult, neurological behavior function was assessed via Morris water maze (MWM) test.. HI cause significant higher mortality in male than in female (P=0.0445). Among the surviving animal, HI affect significantly the body growth, brain growth, MBP expression, and neurological behavior. EPO treatments at both early and late time points significantly benefit the rats in injury recovery, in which they promoted weight gains, reduced brain edema, as well as improved spatial learning ability and memory.. We demonstrated a single dose of EPO at 5000U/kg immediately or 48h after HI injury had significant benefit for the P2 rats in injury recovery, and there was no adverse effect associated with either EPO treatment.

Topics: Age Factors; Analysis of Variance; Animals; Animals, Newborn; Body Weight; Brain Edema; Developmental Disabilities; Disease Models, Animal; Erythropoietin; Hypoxia-Ischemia, Brain; Maze Learning; Myelin Basic Protein; Neuroprotective Agents; Rats; Rats, Sprague-Dawley

The inflammatory mediator lipopolysaccharide (LPS) has been shown to induce acute gliosis in neonatal mice. However, the progressive effects on the murine neurodevelopmental program over the week that follows systemic inflammation are not known. Thus, we investigated the effects of repeated LPS administration in the first postnatal week in mice, a condition mimicking sepsis in late preterm infants, on the developing central nervous system (CNS).. Systemic inflammation was induced by daily intraperitoneal administration (i.p.) of LPS (6 mg/kg) in newborn mice from postnatal day (PND) 4 to PND6. The effects on neurodevelopment were examined by staining the white matter and neurons with Luxol Fast Blue and Cresyl Violet, respectively. The inflammatory response was assessed by quantifying the expression/activity of matrix metalloproteinases (MMP), toll-like receptor (TLR)-4, high mobility group box (HMGB)-1, and autotaxin (ATX). In addition, B6 CX3CR1(gfp/+) mice combined with cryo-immunofluorescence were used to determine the acute, delayed, and lasting effects on myelination, microglia, and astrocytes.. LPS administration led to acute body and brain weight loss as well as overt structural changes in the brain such as cerebellar hypoplasia, neuronal loss/shrinkage, and delayed myelination. The impaired myelination was associated with alterations in the proliferation and differentiation of NG2 progenitor cells early after LPS administration, rather than with excessive phagocytosis by CNS myeloid cells. In addition to disruptions in brain architecture, a robust inflammatory response to LPS was observed. Quantification of inflammatory biomarkers revealed decreased expression of ATX with concurrent increases in HMGB1, TLR-4, and MMP-9 expression levels. Acute astrogliosis (GFAP(+) cells) in the brain parenchyma and at the microvasculature interface together with parenchymal microgliosis (CX3CR1(+) cells) were also observed. These changes preceded the migration/proliferation of CX3CR1(+) cells around the vessels at later time points and the subsequent loss of GFAP(+) astrocytes.. Collectively, our study has uncovered a complex innate inflammatory reaction and associated structural changes in the brains of neonatal mice challenged peripherally with LPS. These findings may explain some of the neurobehavioral abnormalities that develop following neonatal sepsis.

Topics: Age Factors; Anethole Trithione; Animals; Animals, Newborn; Body Weight; Cerebellum; CX3C Chemokine Receptor 1; Demyelinating Diseases; Developmental Disabilities; Gene Expression Regulation; Green Fluorescent Proteins; HMGB1 Protein; Inflammation; Lipopolysaccharides; Mice; Mice, Inbred C57BL; Mice, Transgenic; Microglia; Myelin Basic Protein; Nervous System Malformations; Neurodegenerative Diseases; Receptors, Chemokine; Time Factors; Toll-Like Receptor 4

SLC25A12, a susceptibility gene for autism spectrum disorders that is mutated in a neurodevelopmental syndrome, encodes a mitochondrial aspartate-glutamate carrier (aspartate-glutamate carrier isoform 1 [AGC1]). AGC1 is an important component of the malate/aspartate shuttle, a crucial system supporting oxidative phosphorylation and adenosine triphosphate production.. We characterized mice with a disruption of the Slc25a12 gene, followed by confirmatory in vitro studies.. Slc25a12-knockout mice, which showed no AGC1 by immunoblotting, were born normally but displayed delayed development and died around 3 weeks after birth. In postnatal day 13 to 14 knockout brains, the brains were smaller with no obvious alteration in gross structure. However, we found a reduction in myelin basic protein (MBP)-positive fibers, consistent with a previous report. Furthermore, the neocortex of knockout mice contained abnormal neurofilamentous accumulations in neurons, suggesting defective axonal transport and/or neurodegeneration. Slice cultures prepared from knockout mice also showed a myelination defect, and reduction of Slc25a12 in rat primary oligodendrocytes led to a cell-autonomous reduction in MBP expression. Myelin deficits in slice cultures from knockout mice could be reversed by administration of pyruvate, indicating that reduction in AGC1 activity leads to reduced production of aspartate/N-acetylaspartate and/or alterations in the dihydronicotinamide adenine dinucleotide/nicotinamide adenine dinucleotide(+) ratio, resulting in myelin defects.. Our data implicate AGC1 activity in myelination and in neuronal structure and indicate that while loss of AGC1 leads to hypomyelination and neuronal changes, subtle alterations in AGC1 expression could affect brain development, contributing to increased autism susceptibility.

Topics: Aggrecans; Animals; Animals, Newborn; Brain; Calbindins; Cells, Cultured; Cerebellum; Developmental Disabilities; Disease Models, Animal; Embryo, Mammalian; Encephalitis; Gene Expression Regulation, Developmental; Green Fluorescent Proteins; Male; Membrane Transport Proteins; Mice; Mice, Knockout; Mitochondrial Membrane Transport Proteins; Mitochondrial Proteins; Myelin Basic Protein; Myelin-Associated Glycoprotein; Neurons; Oligodendroglia; Organ Culture Techniques; Pyruvic Acid; Receptors, Cell Surface; S100 Calcium Binding Protein G; Stem Cells

A Japanese boy with the typical manifestations of 18q-syndrome and delayed myelination on magnetic resonance imaging is described. Cytogenetic investigation revealed a deletion at 18q21.3. Three serial magnetic resonance images demonstrated that myelination in the central nervous system was delayed except for the corpus callosum and brainstem. This pattern of delayed myelination appears to be peculiar to the 18q- syndrome. Because the gene for myelin basic protein has been localized to the distal end of the long arm of chromosome 18, we speculate that the abnormal myelination in our patient was partly due to the failure of expression of the myelin basic protein gene.

Topics: Brain; Brain Stem; Child, Preschool; Chromosome Aberrations; Chromosome Deletion; Chromosome Disorders; Chromosomes, Human, Pair 18; Corpus Callosum; Demyelinating Diseases; Developmental Disabilities; Glucuronidase; Humans; Magnetic Resonance Imaging; Male; Muscle Hypotonia; Myelin Basic Protein; Neurologic Examination