Diets rich in SFA have been implicated in Alzheimer's disease (AD). There is strong evidence to suggest that microglial activation augments the progression of AD. However, it remains uncertain whether SFA can initiate microglial activation and whether this response can cause neuronal death.
View Article and Find Full Text PDFMicroglial cells exhibit Notch-1 signaling expression which is enhanced upon activation. We reported previously that enhanced Notch-1 expression in activated microglia modulates production of proinflammatory cytokines and nitric oxide (NO). Furthermore, Notch-1 modulates transcription factor nuclear factor-kappa B (NF-κB).
View Article and Find Full Text PDFBlast injury to the brain is one of the major causes of death and can also significantly affect cognition and physical and psychological skills in survivors of blast. The complex mechanisms via which blast injury causes impairment of cognition and other symptoms are poorly understood. In this study, we investigated the effects of varying degrees of primary blast overpressure (BOP; 80 and 200 kPa) on the pathophysiological and magnetic resonance imaging (MRI) changes and neurocognitive performance as assessed by the monkey Cambridge Neuropsychological Test Automated Battery (mCANTAB) in non-human primates (NHP).
View Article and Find Full Text PDFFront Biosci (Schol Ed)
June 2011
The developing brain is susceptible to hypoxic damage because of its high oxygen and energy requirements. Hypoxia-induced inflammatory response has been recognized as one of the main culprits in the development of hypoxic brain injury. In this regard, a hallmark feature is microglial activation which results in overproduction of inflammatory cytokines, free radicals and nitric oxide.
View Article and Find Full Text PDFCostunolide, a sesquiterpene lactone present in Costus speciosus root exerts a variety of pharmacological activity but its effects on neuroinflammation have not been studied. Microglia, the resident phagocytic cells in the central nervous system respond to neuroinflammation and their overwhelming response in turn aggravate brain damage during infection, ischemia and neurodegenerative diseases. In this study, we report the effect of Costunolide on the production of proinflammatory mediators and mechanisms involved in BV2 microglial cells stimulated with LPS.
View Article and Find Full Text PDFBackground: Nox-2 (also known as gp91phox), a subunit component of NADPH oxidases, generates reactive oxygen species (ROS). Nox-dependent ROS generation and nitric oxide (NO) release by microglia have been implicated in a variety of diseases in the central nervous system. Dexamethasone (Dex) has been shown to suppress the ROS production, NO release and inflammatory reaction of activated microglial cells.
View Article and Find Full Text PDFThe incidence of blast attacks and resulting traumatic brain injuries has been on the rise in recent years. Primary blast is one of the mechanisms in which the blast wave can cause injury to the brain. The aim of this study was to investigate the effects of a single sub-lethal blast over pressure (BOP) exposure of either 48.
View Article and Find Full Text PDFRecent studies demonstrated that the molecules secreted from astrocytes play important roles in the cell fate determination of neural stem cells (NSCs). However, the exact molecules involved and its possible mechanisms in the process remain largely unknown. In this study, astrocyte-conditioned medium (ACM) obtained from astrocytes unstimulated or stimulated by lipopolysaccharide was prepared to treat NSCs.
View Article and Find Full Text PDFDiabetic-induced neural tube defects in embryos are caused by apoptosis of neural progenitor cells (NPCs); however, the underlying mechanisms are poorly understood. The present study is aimed to investigate the specific cellular proteins that may be involved in apoptosis of NPCs. We show here that hyperglycemia-induced apoptosis of NPCs was through a PKCδ-dependent mechanism.
View Article and Find Full Text PDFHypoxic injury, including that resulting in the retinopathy of prematurity, may induce retinal ganglion cell (RGC) death in the neonatal retina. We hypothesized that this may be mediated by excess production of tumour necrosis factor-α (TNF-α) and interleukin-1β (IL-1β) by microglia. One-day-old Wistar rats were subjected to hypoxia for 2 h and the expression of TNF-α and IL-1β and their receptors was determined in the retina.
View Article and Find Full Text PDFMelatonin, an endogenously produced neurohormone secreted by the pineal gland, has a variety of physiological functions and neuroprotective effects. It can modulate the functions of neural stem cells (NSCs) including proliferation and differentiation in embryonic brain tissue but its effect and mechanism on the stem cells in hypoxia remains to be explored. Here, we show that melatonin stimulates proliferation of NSCs during hypoxia.
View Article and Find Full Text PDFHorizontal transfer of genetic material between complex organisms often involves transposable elements (TEs). For example, a DNA transposon mariner has been shown to undergo horizontal transfer between different orders of insects and between different phyla of animals. Here we report the discovery and characterization of an ITmD37D transposon, MJ1, in Anopheles sinensis.
View Article and Find Full Text PDFThe genome of bread wheat (Triticum aestivum) is predicted to be greater than 16 Gbp in size and consist predominantly of repetitive elements, making the sequencing and assembly of this genome a major challenge. We have reduced genome sequence complexity by isolating chromosome arm 7DS and applied second-generation technology and appropriate algorithmic analysis to sequence and assemble low copy and genic regions of this chromosome arm. The assembly represents approximately 40% of the chromosome arm and all known 7DS genes.
View Article and Find Full Text PDFThe POU family transcription factor OCT4 is required for maintaining the pluripotency of embryonic stem cells and for generating induced pluripotent stem cells. Although OCT4 is clearly shown to be expressed in some pluripotent germ cell tumours, its expression in human somatic tumours remains controversial. Some studies have shown that OCT4 is expressed in adult stem cells, somatic cancers and, further, cancer stem cells, while other studies failed to make such an observation.
View Article and Find Full Text PDFThe present study was focused on identifying the expression of N-methyl D-aspartate receptor (NMDAR) subunits on activated microglia and to determine their role in the pathogenesis of periventricular white matter damage (PWMD) in neonatal rats following hypoxia. One day old wistar rats were subjected to hypoxia (5% O(2) ; 95% N(2) ) and the mRNA and protein expression of NMDAR subunits (NR1, NR2A-D, and NR3A) in the periventricular white matter (PWM) was determined at different time points (3,24 h, 3, 7, and 14 days) following hypoxic exposure. Immunoexpression of NR1 and NR2A-D was localized in amoeboid microglial cells (AMC) suggesting the presence of functional NMDARs in them.
View Article and Find Full Text PDFSphingosine kinase 1 (SphK1), a key enzyme responsible for phosphorylating sphingosine into sphingosine-1-phosphate (S1P) has been shown to be expressed in monocytes and monocyte-derived peripheral macrophages. This study demonstrates SphK1 immunoexpression in amoeboid microglial cells (AMC), a nascent monocyte-derived brain macrophage in the corpus callosum of developing rat brain. SphK1 immunofluorescence expression, which appeared to be weak in AMC in normal brain, was markedly induced by lipopolysaccharide (LPS) or hypoxia treatment.
View Article and Find Full Text PDFMajor changes in arterial pressure, autonomic, and respiratory activity occur in response to hypoxia. We analyzed structural damage and increased vascular permeability in the ventrolateral medulla and nucleus tractus solitarius, which control autonomic, respiratory, and cardiovascular functions in adult Wistar rats subjected to 2 hours of hypoxia (7% oxygen + 93% nitrogen) for up to 14 days after hypoxicexposure. Brainstem tissue levels of vascular endothelial growth factor (VEGF), nitric oxide (NO), and glutamate were significantly increased over control levels after hypoxic injury.
View Article and Find Full Text PDFAmong potential radiological, nuclear, biological and chemical weapons, cholinergic nerve agents from chemical weapons remain a realistic terrorist threat due to its combination of high lethality, demonstrated use and relative abundance of un-destroyed stockpiles in various militaries around the world. While current fielded antidotes are able to mitigate acute poisoning, effective neuroprotection in the field remains a challenge amongst subjects with established status epilepticus following nerve agent intoxication. Due to ethical, safety and surety issues, extensive preclinical and clinical research on cholinergic nerve agents is not possible.
View Article and Find Full Text PDFSpinal cord injury (SCI) damages axons and disrupts myelination interrupting sensory and motor neuronal transmission to and from the brain. Patients suffering from SCI although continue to survive, are often left chronically disabled and with no promise of a cure. Advances in stem cell biology has opened up doors for the use of human embryonic, adult neural and induced pluripotent stem cell strategies for SCI.
View Article and Find Full Text PDFVariations in the arterial supply of the upper limb are relatively common, with reported prevalence rates ranging from 11 to 24.4%. Of these, the most commonly encountered variation in the arm is a high origin of the radial artery.
View Article and Find Full Text PDFBackground: Insect innate immunity can be affected by juvenile hormone (JH) and 20-hydroxyecdysone (20E), but how innate immunity is developmentally regulated by these two hormones in insects has not yet been elucidated. In the silkworm, Bombyx mori, JH and 20E levels are high during the final larval molt (4 M) but absent during the feeding stage of 5(th) instar (5 F), while JH level is low and 20E level is high during the prepupal stage (PP). Fat body produces humoral response molecules and hence is considered as the major organ involved in innate immunity.
View Article and Find Full Text PDF20-Hydroxyecdysone (20E) and juvenile hormone (JH) control a variety of physiological events during insect development and metamorphosis. To understand how 20E and JH developmentally regulate energy metabolism in insects, we performed a genome-wide microarray analysis of fat body tissues isolated from the silkworm, Bombyx mori. Many genes involved in energy metabolism, including genes in the glycolytic pathway, were down-regulated during molting and pupation, when 20E levels are high.
View Article and Find Full Text PDFMicroglial cells constitutively express Notch-1 and nuclear factor-kappaB/p65 (NF-kappaB/p65), and both pathways modulate production of inflammatory mediators. This study sought to determine whether a functional relationship exists between them and, if so, to investigate whether they synergistically regulate common microglial cell functions. By immunofluorescence labeling, real-time polymerase chain reaction (RT-PCR), flow cytometry, and Western blot, BV-2 cells exhibited Notch-1 and NF-kappaB/p65 expression, which was significantly up-regulated in cells challenged with lipopolysaccharide (LPS).
View Article and Find Full Text PDFCulexpipiens quinquefasciatus (C. quinquefasciatus) is an important vector that can transmit human diseases such as West Nile virus, lymphatic filariasis, Japanese encephalitis and St. Louis encephalitis.
View Article and Find Full Text PDFAlthough Bombyx mori systematic immunity is extensively studied, little is known about the silkworm's intestine-specific responses to bacterial infection. Antimicrobial peptides (AMPs) gene expression analysis of B. mori intestinal tissue to oral infection with the Gram-positive (Staphylococcus aureus) and -negative (Escherichia coli) bacteria revealed that there is specificity in the interaction between host immune responses and parasite types.
View Article and Find Full Text PDF